REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

 

 

Apresentação

 

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. [Saiba mais]

 

Comunidade no repositório

Selecione a comunidade para navegar nas coleções.

Submissões recentes

  • IPEN-DOC 27159

    LOPES, RENATO P.; PEREIRA, JAMIL C.; DILLENBURG, SERGIO R.; TATUMI, SONIA H.; YEE, MARCIO; FIGUEIREDO, ANA M.G. ; KINOSHITA, ANGELA; BAFFA, OSWALDO. Late Pleistocene-Holocene fossils from Mirim Lake, Southern Brazil, and their paleoenvironmental significance: I - Vertebrates. Journal of South American Earth Sciences, v. 100, p. 1-19, 2020. DOI: 10.1016/j.jsames.2020.102566

    Abstract: Mirim Lake is located in the southern Brazilian/northeastern Urugayan coastal plain. Fossils of mollusks have been discovered on its shores since the XIX century, and in recent years, several new remains of invertebrates and vertebrates have been found in the Brazilian area of the lake that provide insights on the geological evolution and environmental changes that affected this lake during the late Quaternary. In this first of two papers describing these new findings we focus on vertebrates, consisting of aquatic and terrestrial taxa. The former include the first associated fossil remains of one adult and one juvenile balaenid whale known in Brazil, probably a female and calf of the southern right whale (baleia-franca) Eubalaena australis, besides bull sharks (Carcharhinus leucas) also recorded for the first time in southern Brazil, rays (Dasyatidae and Myliobatidae) and teleost fishes. The fossils of terrestrial vertebrates include several extinct mammals, found on the margins and retrieved from the lake bottom by fishermen at depths of up to 4 m. One molar tooth of Toxodon discovered in situ in one irrigation channel yielded an electron spin resonance (ESR) age of 68 ± 13 ka, in agreement with an age of 32.8 ± 5.1 ka obtained in quartz grains extracted from a caliche nodule collected above that fossil and dated by optically-stimulated luminescence (OSL). Other quartz grains in the same nodule that yielded ages of 16.9 ± 2.5 ka indicate partial dissolution of the caliche by increased rainfall at the beginning of the last glacialinterglacial transition (Termination I) . The lake was invaded by marine waters and organisms during the Holocene sea-level highstand of +3 m around 5–6 ka b2k through paleo-connections with the Atlantic Ocean, becoming a paleo-lagoon. At that time coastal waters were warmer than today, as indicated by the presence of the tropical shark C. leucas. The ESR and OSL ages indicate chronocorrelation with the Pleistocene fossil-bearing Santa Vitória Formation that outcrops to the east. The fossil and sedimentary records indicate that the geological evolution and environmental conditions of the lake were controlled by climate and sea-level oscillations related to glacial-interglacial cycles.

    Icon

  • IPEN-DOC 27158

    FARIA, FABIO H.C.; KINOSHITA, ANGELA; CARVALHO, ISMAR de S.; ARAUJO-JUNIOR, HERMINIO I. de; PEGORIN, PRISCILA; FIGUEIREDO, ANA M.G. ; BAFFA, OSWALDO. ESR dating of late Quaternary megafauna fossils from João Dourado, Bahia, Brazil. Journal of South American Earth Sciences, v. 101, p. 1-7, 2020. DOI: 10.1016/j.jsames.2020.102586

    Abstract: We applied the ESR (Electron Spin Resonance) dating method to fossils of Notiomastodon platensis (two teeth) and Toxodontinae (two teeth) found in the fossiliferous deposit of Lajedão do Patrício, João Dourado, State of Bahia, Brazil, to identify the period of formation of this fossil accumulation. Neutron Activation Analysis was applied to determine the concentrations of the main radioisotopes in enamel, dentine and sediment. The ages found for N. platensis are 16.8 ± 2.6 ka and 12.5 ± 2.3 ka, while the ages for Toxodontinae are 9.6 ± 1 ka and 9.1 ± 1 ka. The results for Notiomastodon. platensis and Toxodontinae are similar to other fossiliferous of Brazil. The estimated maximum time-averaging for Lajedão do Patrício is 11.3 ka, indicating a long period of accumulation of skeletal remains, attributed to resedimentation and reworking. The crossing between the period of formation of fossil assemblage Lajedão do Patrício and ages of climatic variations diponible in paleoclimatic curves produced for the Quaternary of northeastern Brazil indicates different climatic and environmental conditions during the formation of the deposit.

    Icon

  • IPEN-DOC 27157

    GONZALES-LORENZO, CARLOS D.; WATANABE, SHIGUEO; CAVALIERI, TASSIO A. ; CANO, NILO F.; RAO, T.K.G.; CHUBACI, JOSE F.D.; CARMO, LUCAS S. ; BUENO, CARMEN C. . Calculated and experimental response of calcium silicate polycrystalline to high and very-high neutron doses. Radiation Physics and Chemistry, v. 172, p. 1-7, 2020. DOI: 10.1016/j.radphyschem.2020.108820

    Abstract: In the scope to the discovery of new detectors for high and very-high gamma and neutron radiation dose (mGy- MGy), synthetic polycrystals of CaSiO3 have been produced by the devitrification method in our laboratory. CaSiO3 polycrystals were irradiated with thermal, epithermal and a small fraction of fast neutrons. In the position of irradiation, the thermal neutron flux is about 83% of the total neutron flux and the thermal neutron fluences range from 5.82 × 1013 to 2.97 × 1016 n/cm2. This thermal neutron reacts with Ca, Si and O through (n,γ) process, all or part of the gamma emitted in this reaction is absorbed by the sample and is responsible for the induction of thermoluminescence (TL). The total energy emitted by the (n,γ) reaction was calculated analytically. Furthermore, Monte Carlo simulations using MCNP5 radiation transport code was carried out to calculate the deposited dose on CaSiO3 by the neutron interaction finding doses ranging from 42 Gy to 21 kGy. CaSiO3 TL glow curves, after radiation exposure from the reactor, display the main prominent TL peak around 234–259 °C and when exposed to gamma radiation (Co-60) it shows the main TL peak around same 234–272 °C.

    Icon

  • IPEN-DOC 27156

    AZEVEDO, LUCIANA C. de ; ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; DIAS, DJALMA B. ; NASCIMENTO, SANDI S.; OLIVEIRA, FABIO F.; SILVA, LEONARDO G.A. ; FUNGARO, DENISE A. . Biodegradable films derived from corn and potato starch and study of the effect of silicate extracted from sugarcane waste ash. ACS Applied Polymer Materials, v. 2, n. 6, p. 2160-2169, 2020. DOI: 10.1021/acsapm.0c00124

    Abstract: The growing concern with the amount of plastic materials found in the oceans makes it necessary to develop biodegradable materials that have low toxicity to marine animals and humans, but at the same time are resistant to the actions of microorganisms such as fungi or bacteria. On the other hand, agricultural waste rich in inorganic materials (such as silica) is often discarded, while it could be reused as a source of raw material. Considering these points, sodium silicate solution extracted from sugarcane waste ash was utilized to prepare biodegradable bioplastics based on corn starch and potato starch. The starch-based bioplastics were produced by casting and characterized by several physical-chemical techniques evaluating tensile strength, elongation at break, color analyses, transparency, opacity, moisture, and biodegradation assay. Bioplastics prepared with corn starch presented better physical, mechanical, and thermal properties and optical quality than bioplastics based on potato starch. The samples called CS3 and PS3, with 5.0% glycerol, were the most resistant to tensile strengths of 0.73 and 0.36 MPa, respectively. On the other hand, the highest elongation at break values were found for the samples with 7.5% glycerol (CS9, 52.90% and PS9, 49.33%). Corn starch-based bioplastics were more thermally resistant (CS3, 152.86 °C and CS9, 135.20 °C) when compared to potato starch-based bioplastics (PS3, 140.39 °C and PS9, 127.57 °C). In general, the addition of sodium silicate solution improved the mechanical and thermal properties of both types of bioplastics. The potato starch-based bioplastics were biodegraded in 5 days, while those made from corn starch took almost 40 days. The inclusion of sodium silicate inhibited fungal growth for both corn starch and potato starch bioplastics. The results suggest that sodium silicate solution obtained from renewable sources can be incorporated into starch-based bioplastics for production of biodegradable packaging with antifungal activity.

    Icon

  • IPEN-DOC 27155

    RABELO, THAIS F. ; ZAMATARO, CLAUDIA B. ; KUCHAR, NIELSEN G. ; ZANINI, NATHALIA ; JUVINO, AMANDA C. ; DEL-VALLE, MATHEUS; CASTRO, PEDRO A.A. ; SANTOS, MOISES O. ; ZEZELL, DENISE M. . Human dental enamel evaluation after radiotherapy simulation and laminates debonding with Er,Cr:YSGG using SEM and EDS. Journal of Oral Diagnosis, v. 4, p. 1-5, 2019. DOI: 10.5935/2525-5711.20190022

    Abstract: The pursuit of perfection makes younger people undergo aesthetic procedures without formal indication. However, young patients may be susceptible to a disease such as head and neck cancer which treatment can compromise the adhesion of these indirect mate-rials. Here, we present an analyze, of the gamma radiation effects on crystallographic morphology of human dental enamel after laminate veneer debonding with Er,Cr:YSGG laser. Thus, human dental enamel samples were prepared and randomized into 2 groups (n=10): Laser Irradiation (L) and Gamma + Laser Irradiation (GL) group. Scanning elec-tron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were performed before bonding and after debonding using Er,Cr:YSGG. Only Gamma + Laser Irradia-tion group received a cumulative dose of 70 Gy gamma radiation used in head and neck cancer radiotherapy. SEM images showed that both GL and L groups presented altered morphology. EDS showed an decrease in Ca and P intensities after laser debonding of laminates veneers in both group. Therefore, a proper laser facet removal protocol should be established for healthy patients and patients who have been exposed to radiotherapy for head and neck cancer.

    Icon

  • IPEN-DOC 27154

    SABINO, CAETANO P.; WAINWRIGHT, MARK; RIBEIRO, MARTHA S. ; SELLERA, FABIO P.; ANJOS, CAROLINA dos; BAPTISTA, MAURICIO da S.; LINCOPAN, NILTON. Global priority multidrug-resistant pathogens do not resist photodynamic therapy. Journal of Photochemistry and Photobiology B: Biology, v. 208, p. 1-9, 2020. DOI: 10.1016/j.jphotobiol.2020.111893

    Abstract: Microbial drug-resistance demands immediate implementation of novel therapeutic strategies. Antimicrobial photodynamic therapy (aPDT) combines the administration of a photosensitizer (PS) compound with low-irradiance light to induce photochemical reactions that yield reactive oxygen species (ROS). Since ROS react with nearly all biomolecules, aPDT offers a powerful multitarget method to avoid selection of drug-resistant strains. In this study, we assayed photodynamic inactivation under a standardized method, combining methylene blue (MB) as PS and red light, against global priority pathogens. The species tested include Acinetobacter baumannii, Klebsiella aerogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecium, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and Cryptococcus neoformans. Our strain collection presents resistance to all tested antimicrobials (> 50). All drug-resistant strains were compared to their drugsensitive counterparts. Regardless of resistance phenotype, MB-aPDT presented species-specific dose-response kinetics. More than 5log10 reduction was observed within less than 75 s of illumination for A. baumannii, E. coli, E. faecium, E. faecalis and S. aureus and within less than 7 min for K. aerogenes, K. pneumoniae, P. aeruginosa, C. albicans and C. neoformans. No signs of correlations in between drug-resistance profiles and aPDT sensitivity were observed. Therefore, MB-aPDT can provide effective therapeutic protocols for a very broad spectrum of pathogens. Hence, we believe that this study represents a very important step to bring aPDT closer to implementation into mainstream medical practices.

    Icon

  • IPEN-DOC 27153

    CORRÊA, BRUNO S.; COSTA, MESSIAS S. ; CABRERA-PASCA, GABRIEL A. ; SENA, CLEIDILANE ; PINTO, RAFAEL H.H.; SILVA, ANA P.S.; CARVALHO JUNIOR, RAUL N.; ISHIDA, LINA; RAMON, JONATHAN G.A.; FREITAS, RAFAEL S.; SAIKI, MITIKO ; MATOS, IZABELA T. ; CORRÊA, EDUARDO L. ; CARBONARI, ARTUR W. . High-saturation magnetization in small nanoparticles of Fe3O4 coated with natural oils. Journal of Nanoparticle Research, v. 22, n. 3, p. 1-15, 2020. DOI: 10.1007/s11051-020-4761-5

    Abstract: The enhancement of nanoparticle’s magnetic properties with a suitable coating is the main tool to increase their potential as an effective candidate for applications in different areas, especially in biomedicine. In the work here reported, Fe3O4 nanoparticles coated with natural oils were synthesized by iron (III) acetylacetonate thermal decomposition and the effects of the coating on the magnetic properties of these particles have been investigated. The oils were extracted from three Amazon fruits seeds: açaí, ucuúba, and bacaba by CO2 supercritical extraction process, and the relative percentage composition of fatty acids were determined by gas chromatography. A systematic study of crystalline, morphological, and magnetic properties revealed a saturation magnetization (Ms) enhancement and high values of the anisotropy constant for Fe3O4 samples when coated with açaí and ucuúba oils, which present a large percentage of saturated total fatty acid. Our results indicate that nanoparticles with sizes smaller than around 5 nm present Ms values as high as that found for bulk Fe3O4 and, consequently, much higher than Ms values for nanoparticles usually coated with oleic acid. The nuclear techniques neutron activation analysis and perturbed angular correlations were used to better characterize the nanoparticles.

    Icon

  • IPEN-DOC 27152

    MATOS, B.R. ; GOULART, C.A. ; TOSCO, B.; SILVA, J.S. da ; ISIDORO, R.A. ; SANTIAGO, E.I. ; LINARDI, M. ; SCHADE, U.; PUSKAR, L.; FONSECA, F.C. ; TAVARES, A.C.. Properties and DEFC tests of Nafion: functionalized titanate nanotubes composite membranes prepared by melt-extrusion. Journal of Membrane Science, v. 604, p. 1-7, 2020. DOI: 10.1016/j.memsci.2020.118042

    Abstract: Nafion based composites are promising materials to improve the performance of direct ethanol fuel cells. In this work, composite membranes of Nafion and titanate nanotubes functionalized with sulfonic acid groups were prepared by melt-extrusion and tested in a direct ethanol fuel cell. Far and mid infrared spectroscopies evidenced the formation of ionic bridges between the sulfonic acid groups of both functionalized nanoparticles and the ionomer. Small angle X-ray scattering measurements revealed that the melt-extrusion method leads to an uniform distribution of the inorganic phase in the ionomer matrix. Such structural analysis indicated that the improved the proton conduction properties of the composites, even with the addition of a high concentration of functionalized nanoparticles, are an outcome of the synergistic ionic network due to the hydrid organic/inorganic proton conducting phases. However, an improvement of the fuel cell performance is observed for 2.5 wt% of functionalized titanate nanotubes, which is a result of the lower ethanol crossover and the plasticizing effect of the aliphatic segments of the organic moieties grafted at the surface of the titanate nanoparticles.

    Icon

  • IPEN-DOC 27151

    ANTUZEVICS, ANDRIS; FEDOTOVS, ANDRIS; BERZINS, DZINTARS; ROGULIS, ULDIS; AUZINS, KRISJANIS; ZOLOTARJOVS, ALEKSEJS; BALDOCHI, SONIA L. . Recombination luminescence of X-ray induced paramagnetic defects in BaY2F8. Journal of Luminescence, v. 223, p. 1-6, 2020. DOI: 10.1016/j.jlumin.2020.117216

    Abstract: Recombination luminescence (RL) and RL-detected electron paramagnetic resonance (RL-EPR) in BaY2F8 single crystal has been investigated after irradiation with X-rays at low temperature. The recombination process, which lasts for several hours at 4 K, results in several broad bands in the RL spectrum. RL-EPR spectra show pronounced angular dependences on crystal orientation relative to external magnetic field. Based on the determined spin-Hamiltonian parameter values the recombination centres have been proposed to be F-type electron and self-trapped hole (VK) centres.

    Icon

  • IPEN-DOC 27150

    BARDELLA, FERNANDO ; RODRIGUES, ANDRE M. ; LEAL NETO, RICARDO M. . Crystalwalk: an educational interactive software for synthesis and visualization of crystal structures. Journal of Materials Education, v. 41, n. 5-6, p. 157-180, 2019.

    Icon

  • IPEN-DOC 27149

    MUTARELLI, RITA de C. ; LIMA, ANA C. de S.; SANTOS, JOAQUIM R. dos; SABUNDJIAN, GAIANE. IPEN radiopharmaceutical market trends: an approach to system dynamics. International Journal of Development Research, v. 9, n. 12, p. 32542-32555, 2019.

    Abstract: The Instituto de Pesquisas Energéticas e Nucleares (IPEN) is today responsible for providing radiopharmaceuticals for 80% of nuclear medicine procedures in Brazil. The aim of this study is to analyze the impact of different radiopharmaceutical demands on IPEN production. The methodology used in this study is based on the system dynamics simulation paradigm, combined with empirical data obtained from the institutions and regulatory authorities. The results from the simulations suggest that the IPEN's response to different demands depends on how it balances policies acting on the supply and demand for the resources. Sustainable and long-term management of this market requires active monitoring to support events caused by changes in demand. This study contributes to the systems dynamics and also to the radiopharmaceutical management literature, presenting an integrative model to evaluate the resilience of a specific market. Although there are previous studies on this subject in other countries, the present one focuses on the role that IPEN plays in this market and integrates several variables in a simulation process to understand the market as a whole. For this reason, this work is original in the area of radiopharmaceuticals.

    Palavras-Chave: brazilian cnen; nuclear medicine; radiopharmaceuticals; production; supply and demand; dynamic function studies; dynamical systems; investment; computerized simulation; interactions; forecasting; statistical models

    Icon

  • IPEN-DOC 27148

    VILLANI, DANIEL ; MORENO, CAROLINA dos S.; SAKURABA, ROBERTO K.; CAMPOS, LETICIA L. . Application of OSL dosimetry and 3D printed phantom for comparison of calculation algorithms for VMAT treatment planning. QUARKS: Brazilian Electronic Journal of Physics, Chemistry and Material Science, v. 1, n. 1, p. 30-39, 2019. DOI: 10.34019/2674-9688.2019.v1.28227

    Abstract: The application of new commercial and industrial technologies in the fields of dosimetry and medical physics is of great interest to the scientific community, both to validate existing protocols and to develop new methodologies. The popularization of 3D printing techniques has been analyzed as a great advantage in quality control in complex treatment techniques, such as radiotherapy and the development of patient simulators. Portable dosimetry systems such as Landauer MicroStar OSL system are versatile and their use in quality control is of great importance. The aim of this paper is to compare two of the most used dose calculation algorithms used in Varian Eclipse TPS – AAA and Acuros XB – for treatment planning of multiple brain metastases using a 3D printed anthropomorphic phantom and the OSL InLight system for experimental dosimetry validation. A 3D printed anthropomorphic skull phantom was submitted to a CT scan and planed five target volumes. In order of comparison, two dose calculations were performed in the Varian Eclipse 13.6 TPS with "Alabama technique", using the Varian’s AAA and AXB algorithms, and treatment delivered with 6 MV photon beam of a Varian TrueBeam linear accelerator. Landauer nanoDot dosimeters were positioned inside each of the five target volumes planned and the experimental dosimetric results were compared with the algorithms’ calculated doses. The findings of this work indicate that ACUROS XB calculates more accurate doses compared with AAA, with all the experimental agreements better than 96.0 %, probably because of the heterogeneity corrections. The uncertainty analysis of the InLight system device is enough to sustain the dosimetric uncertainties below 3.0 %, validating the results.

    Palavras-Chave: dosimetry; luminescent dosemeters; phantoms; calculation methods; algorithms; radiation doses; radiation dose distributions; radiotherapy; planning; brain; metastases

    Icon

  • IPEN-DOC 27140

    SOUZA, LUIZA F. de; SOUZA, DIVANIZIA N.; RIVERA, GERARDO B.; VIDAL, ROGERIO M.; CALDAS, LINDA V.E. . Dosimetric characterization of MgB4O7:Ce,Li as an optically stimulated dosimeter for photon beam radiotherapy. Perspectives in Science, v. 12, p. 1-3, 2019. DOI: 10.1016/j.pisc.2019.100397

    Abstract: Currently there is a growing interest in the development of optically stimulatedluminescence (OSL) dosimeters that may be useful for assessing the neutron flux contribution onthe doses in radiotherapy due to neutrons produced in the interaction of megavoltage photonbeams. In this work, OSL responses of MgB4O7:Ce,Li with11B are presented for some photonbeams, including 6 MV and 10 MV. For 10 MV, the behavior of the phosphor containing10B wasalso evaluated. The material with10B exhibited an OSL response slightly more intense thanthat with11B, indicating a possible application of this new material for dosimetry in photonradiotherapy.

    Palavras-Chave: thermoluminescence; radioluminescence; photon beams; magnesium; borates; radiotherapy; dosemeters; dosimetry

    Icon

  • IPEN-DOC 27147

    SOUZA, A.P.S.; OLIVEIRA, L.P. de; YOKAICHIYA, F.; GENEZINI, F.A. ; FRANCO, M.K.K.D. . Neutron Guide Building instruments of the Brazilian Multipurpose Reactor (RMB) project. Journal of Instrumentation, v. 15, n. 4, p. 1-24, 2020. DOI: 10.1088/1748-0221/15/04/P04011

    Abstract: A growing community of scientists has been using neutrons in the most diverse areas of science. In order to meet the researchers demand in the areas of physics, chemistry, materials sciences, engineering, cultural heritage, biology and earth sciences, the Brazilian Multipurpose Reactor (RMB) will provide 3 thermal guides and 3 cold guides, with the installation of several instruments for materials characterization. In this study, we present a standard design requirement of two primordial instruments, namely Sabiá and Araponga. They are, respectively, cold and thermal neutron instruments and correspond to a Small-Angle Neutron Scattering (SANS) and High-Resolution Powder Neutron Diffractometer (HRPND) to be installed in the Neutron Guide Building (N02) of RMB. To provide adequate flux for both instruments, we propose here an initial investigation of the use of simple and split guides to transport neutron beams to two different instruments on the same guide. For this purpose, we use Monte Carlo simulations utilizing McStas software to check the efficiency of thermal neutron transport for different basic configuration and sources. By considering these results, it is possible to conclude that the split guide configuration is, in most cases, more efficient than cases that use transmitted neutron beams independently of source. We also verify that the employment of different coating indexes for concave and convex surfaces on curved guides is crucial, at least on simulated cases, to optimise neutron flux (intensity and divergence) and diminish facility installation cost.

    Palavras-Chave: neutron guides; neutron sources; neutron transport; rmb reactor; buildings; cold neutrons; thermal neutrons; reactor instrumentation; simulators; small angle scattering; neutron diffraction; scattering; monte carlo method

    Icon

  • IPEN-DOC 27146

    OLIVEIRA, L.P. de; SOUZA, A.P.S.; YOKAICHIYA, F.; GENEZINI, F.A. ; FRANCO, M.K.K.D. . Monte Carlo simulations of the S-shaped neutron guide. Journal of Instrumentation, v. 15, n. 1, p. 1-14, 2020. DOI: 10.1088/1748-0221/15/01/P01012

    Abstract: Neutron transport along guides is governed by the Liouville theorem and the technology involved has advanced in recent decades. Computer simulations have proven to be useful tools in the design and conception of neutron guide systems in facilities. In this study, we use a Monte Carlo method to perform simulations for an S-shaped neutron guide with different dimensions for a Small-Angle Neutron Scattering (SANS) instrument, through the MCSTAS software. Awavelength cutoff is observed and shown to be dependent on the geometrical parameters of the guide. Results for the neutron flux at sample position are presented and greater sensitivity of cutoffs concerning the curvatures of the guides than to their lengths is noticed. Our results are in agreement with those obtained from the Acceptance Diagram method and we analyse the beam divergence behaviour along the S-shaped guide.

    Palavras-Chave: monte carlo method; neutron guides; neutron sources; simulation; computerized simulation; computer calculations; shape; neutron transport; small angle scattering; computer codes

    Icon

  • IPEN-DOC 27137

    MONACO, DANIEL F. . FastLAP : desenvolvimento de um pré-processador gráfico visual para o código RELAP5 / FastLAP: development of a graphic visual preprocessor for RELAP5 . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 222 p. Orientador: Gaianê Sabundjian. DOI: 10.11606/D.85.2019.tde-05072019-144235

    Abstract: As energias limpas têm contribuído para o aumento de investimento e pesquisas em energia nuclear na última década. No entanto, as ocorrências dos acidentes nucleares ao longo da história ainda geram insegurança para a população em geral. Os órgãos reguladores têm aumentado as exigências de segurança em plantas nucleares e, devido a isto, vêm fazendo esforços na realização de simulações numéricas com programas computacionais de análise de acidentes em instalações nucleares, com a finalidade de garantir a segurança da planta e da população do entorno, antes mesmo de sua construção. No Brasil, para atender as exigências do órgão regulador brasileiro, a administradora dos reatores nucleares nacionais deve apresentar um estudo termo-hidráulico na área de análise de acidentes e transientes operacionais para as instalações nucleares. Isto é feito com a finalidade de licenciar as plantas nucleares, utilizando ferramentas computacionais apropriadas, tais como o código RELAP5. Esse programa computacional é muito eficiente na simulação de acidentes em usinas nucleares, mas não é muito amigável quanto à inserção de seus dados de entrada. Essa dificuldade motivou o desenvolvimento de pré-processadores para auxiliar a preparação dos dados geométricos de plantas nucleares, que é uma parte dos dados de entrada para o código RELAP5. Além disso, antes de iniciar o uso dessas ferramentas computacionais, faz-se necessário que o usuário monte uma nodalização ou modelagem do problema, de forma a representar mais adequadamente a planta e a fenomenologia envolvida durante um acidente ou transiente, sendo que ambas sejam adequadamente atendidas pela ferramenta. O objetivo desse trabalho foi o de criar um pré-processador capaz de auxiliar o usuário na tarefa de preparar os dados de entrada para o código RELAP5 e, também, de auxiliá-lo na elaboração da nodalização necessária para representar de forma mais real possível a planta em estudo. O pré-processador desenvolvido nesse trabalho é gráfico, visual e amigável, de forma a permitir que o usuário inicie a nodalização com o uso desta ferramenta, integrando assim as etapas de modelagem e preparação dos dados de entrada para o código RELAP5 em uma única fase, reduzindo assim, os esforços necessários para a sua realização, otimizando o tempo gasto. Para atingir esse objetivo, foi utilizado como plataforma de desenvolvimento o MS Excel®, uma ferramenta de planilha de cálculo eletrônica largamente utilizada, e foi construído para ele um complemento por meio da linguagem C# e da plataforma .NET. E através desta linguagem, seus recursos de orientação a objetos e total integração com a ferramenta MS Excel®, como Interop e Visual Studio Tools for Office (VSTO) integrados, foi possível um desenvolvimento mais rápido de uma ferramenta eficiente para essa finalidade, fazendo uso de recursos que não estariam disponíveis por meio do VBA (Visual Basic for Applications). O pré-processador desenvolvido nesse trabalho permite a criação da nodalização de um problema termo-hidráulico, onde os componentes hidrodinâmicos são desenhados por meio da automação de AutoShapes do MS Excel® e os dados de entrada desses componentes são alimentados por meio de caixas de diálogo amigáveis e funcionais. Uma vez que o pré-processador foi criado como um complemento para MS Excel®, as linhas de programação do pré-processador criado não ficam restritas a uma única planilha, facilitando sua atualização e redistribuição. O resultado obtido por meio desse trabalho foi o FastLAP, um pré-processador para RELAP5 visual, robusto e amigável. Por meio do FastLAP, criado nesse trabalho, reduziu-se o esforço do usuário do código RELAP5 tanto no preparo da nodalização como no preparo dos dados de entrada para o código, uma vez que a ferramenta é amigável e exibe tanto os nomes das propriedades conforme definidos pelo código RELAP5, bem como os nomes das grandezas físicas reais que estão sendo representadas. O pré-processador foi testado na elaboração da nodalização e dos dados de entrada do RELAP5 para um problema experimental encontrado na literatura e mostrou-se uma poderosa ferramenta gráfica, ajudando os usuários do RELAP5 a organizar visualmente os dados de entrada e oferecendo condições para analisar os resultados mais rapidamente. Esse trabalho criou não somente uma nova ferramenta de apoio para o usuário RELAP5, mas sim uma nova abordagem para a simulação de acidentes termo-hidráulicos com o código, fundindo as duas etapas: de nodalização e preparação dos dados de entrada.

    Palavras-Chave: simulation; functional models; reactor cooling systems; coupled reactor cores; reactor accidents; excursions; reactor safety; leak detectors; computer codes; graphical user interface; programming; input-output analysis; data visualization; process development units

    Icon

  • IPEN-DOC 27136

    MORAIS, CHRISTIANE S. de . Estudo da evolução das concentrações de metano na última década na Amazônia / Evolution of methane concentration in the last decade in the Amazon . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 66 p. Orientador: Luciana Vanni Gatti. DOI: 10.11606/D.85.2020.tde-21022020-135554

    Abstract: A mudança do uso da terra e o desmatamento para fins de produção agropecuária na Amazônia tem sido motivo de grande preocupação. Atualmente, os estudos acerca das emissões (naturais e antrópicas) de Gases de Efeito Estufa - GEE vêm se intensificando no meio científico. A proposta deste trabalho é realizar estudo da evolução das concentrações de metano no período entre 2010 a 2017 na Amazônia e realizar uma intercomparação entre as medidas de perfis verticais de avião e da coluna total de CH4 utilizando Espectrômetro de Absorção - FTIR nos anos de 2016 a 2017. As coletas do perfil vertical de avião foram realizadas na Floresta Amazônica em RBA (9,01°S, 64,72°O, região localizada entre as cidades de Porto Velho e Rio Branco). As medidas realizadas pelo FTIR foram feitas no município de Porto Velho 8,8°S, 63,9°O. As análises das medidas de perfil vertical de avião foram realizadas no Laboratório de Gases de Efeito Estufa - LaGEE, no Instituto Nacional de Pesquisas Espaciais - INPE, em São José dos Campos - SP, enquanto que as medidas do FTIR foram analisadas pelo Instituto de Aeoronomia da Bélgica (Belgian Institute for Space Aeronomy (BIRA-IASB)). As medidas obtidas nesse trabalho, revelam uma variação interanual com crescimento das concentrações de CH4 no decorrer dos anos. As concentrações de metano obtidas nos perfis verticais de avião são maiores nas alturas mais próximas da superfície, abaixo da camada limite planetária (< 1,5 km), o que é um indicativo que esta região da Amazônia contribui com as emissões de metano para a atmosfera, contudo, a taxa de crescimento das concentrações de CH4 do local de estudo (5,7 ppb ano-1), ainda é menor que a taxa média global (7,7 ppb ano-1). Os resultados da intercomparação entre as medidas de perfil de avião e do FTIR indicam que os perfis de avião validam os resultados obtidos pelo FTIR.

    Palavras-Chave: fourier analysis; emission spectroscopy; fourier transform spectrometers; infrared spectrometers; natural gas; methane; greenhouse gases; hydrocarbons; air pollution; climatic change; amazon river; brazil

    Icon

  • IPEN-DOC 27145

    MONTEIRO, LUCILENA R. ; LANGE, CAMILA N.; FREIRE, BRUNA M.; PEDRON, TATIANA; SILVA, JULIO J.C. da; MAGALHÃES JUNIOR, ARIANO M. de; PEGORARO, CAMILA; BUSANELLO, CARLOS; BATISTA, BRUNO L.. Inter- and intra-variability in the mineral content of rice varieties grown in various microclimatic regions of southern Brazil. Journal of Food Composition and Analysis, v. 92, p. 1-11, 2020. DOI: 10.1016/j.jfca.2020.103535

    Abstract: The most common goal for rice breeding is to improve the nutritional content and to reduce toxic components. Fourteen varieties of rice were grown for this purpose in six microclimatic regions in southern Brazil. The elemental composition of rice and As-Species were measured by ICP-MS and HPLC-ICP-MS, respectively. Intraand inter-species variations of essential and non-essential elements in husked grains from an important riceproducing region in Brazil are presented. Arsenic, Cd, Co, Cu, Fe, Mg, Mn, Ni, Se, and Zn were significantly affected by the microclimatic region and the rice varieties. The only exception observed was the effect of Pb variety selection, with 35.4 % associated with random fluctuations. Varieties with both higher levels of Fe/Zn and lower levels of As/Cd were identified in all regions studied. All regions and varieties were able to produce rice with Cd<10 μg kg−1, but the Santa Vitoria do Palmar region where varieties with Cd<45 μg kg−1 were selected. Well-established varieties result in a higher daily intake of essential elements than the varieties under development. Therefore, our findings may provide information to support the selection procedures for varieties, as well as to encourage improvements in management practices between regions.

    Palavras-Chave: rice; food; safety; safety analysis; arsenic; elements; cadmium; intake; nutrients; chemical composition; microclimates; cultivation; geologic structures; soils

    Icon

  • IPEN-DOC 27144

    ARAUJO, LEANDRO G. de ; PRADO, EDUARDO S.P. ; MIRANDA, FELIPE de S.; VICENTE, ROBERTO ; SILVA SOBRINHO, ARGEMIRO S. da; PETRACONI FILHO, GILBERTO; MARUMO, JULIO T. . Physicochemical modifications of radioactive oil sludge by ozone treatment. Journal of Environmental Chemical Engineering, v. 8, n. 5, p. 1-8, 2020. DOI: 10.1016/j.jece.2020.104128

    Abstract: An experimental study on the degradation of organic compounds from radioactive oil sludge by the ozonation process is presented. The effects of different concentrations of ozone in the oil sludge degradation over time were investigated. The experiments were performed in a 0.125 L glass reactor with magnetic stirring and a diffuser plate at the bottom to feed the ozone. The ozone concentration varied from 13 to 53 mg L−1 and the total interaction time was 1 h. To investigate the physicochemical properties of the oil sludge (solid and liquid components) prior to and after the treatment, multiple analytical characterization methods were used: Thermal Gravimetric Analysis, X-ray diffraction, Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy, Fourier Transform Infrared spectroscopy, Spectrophotometer, and Residual Gas Analyzer. The most perceptive change is in the color of the liquid medium turned from dark brown to light yellow, especially under ozone concentrations higher than 33 mg L−1. Absorbance values decreased about 3.5 times after 30 min of treatment with [O3] =53 mg L−1. FTIR spectroscopy showed that the bands associated with the CH3 and CeH in CH2 disappeared during treatment. On the other hand, a greater presence of C]C aromatics was observed. By residual gas analysis, various organic and inorganic gases were identified during the treatment, such as CH4, H2, CO2, and H2S. Finally, the ozonation of the oil sludge proved to be effective, due to its high reaction capacity.

    Palavras-Chave: ozone; therapy; ozonization; radioactivity; sludges; oxidation; naturally occurring radioactive materials; fourier transformation; thermal gravimetric analysis

    Icon

  • IPEN-DOC 27143

    MATOS, B.R. . The genuine ac-to-dc proton conductivity crossover of nafion and polymer dielectric relaxations as a fuel cell polarization loss. Journal of Electroanalytical Chemistry, v. 871, p. 1-13, 2020. DOI: 10.1016/j.jelechem.2020.114357

    Abstract: The non-ohmic behavior of Nafion electrical properties, i. e., the thickness and potential dependent conductivity, was studied in the impedance, dielectric and conductivity representations with the use of a special through-plane sampleholder in a 4-probe array. Such measurements allowed identifying the genuine ac-to-dc conductivity crossover frequency in Nafion, which occurs for f<10-1 Hz. In addition, the minimization of the interfacial electrode/ionomer polarizations with the 4-probe setup permitted the determination of the bulk dc conductivity and dielectric constant of Nafion, which are σ~0.03 Scm-1 and ε′~106 (T=40 °Cand RH=100%), respectively. The colossal dielectric constant is shown to increase the Debye length of the electric double layer to values comparable to the membrane thickness. Therefore, the exponential increase of the proton conductivity with increasing both membrane thickness and electric potential are a result of canceling out the non-linear effects of electric double layer caused by the high dielectric permittivity of Nafion. The ac-to-dc conductivity crossover in H2/O2 fuel cell impedance curves takes place for f<100 Hz and matches with the ex situ impedance spectroscopy study in excellent agreement, revealing a striking result: the potential dependent conductivity of Nafion requires extra fuel cell overpotential to overcome the electrode/ionomer interfacial polarization representing an additional polarization loss to polymer electrolyte fuel cells.

    Palavras-Chave: ionic conductivity; electric conductivity; electrical properties; fuel cells; electric fields; layers; dielectric properties; electrical properties; nonlinear problems; nmr imaging; spectroscopy

    Icon

  • IPEN-DOC 27142

    SANTOS, M.C.L. ; GODOI, C.M. ; KANG, H.S.; SOUZA, R.F.B. de ; RAMOS, A.S.; ANTOLINI, E.; NETO, A.O. . Effect of Ni content in PdNi/C anode catalysts on power and methanol co-generation in alkaline direct methane fuel cell type. Journal of Colloid and Interface Science, v. 578, p. 390-401, 2020. DOI: 10.1016/j.jcis.2020.06.017

    Abstract: PdNi electrocatalysts supported on carbon were used as anode materials for methane oxidation in alkaline direct methane fuel cells (ADMEFCs). The electrocatalysts were successfully synthesized by the NaBH4 reduction method. X-ray diffraction measurements showed the formation of non-alloyed Pd in the face- centered cubic (FCC) structure for all materials and formation of NiO and Ni(OH)2 species. TEM images showed that the metal particles are well dispersed on the support with small agglomeration regions. Information about the surface structure of the catalyst were obtained by Raman spectra, mainly confirming the presence of Ni(OH)2. The species observed by DEMS, that is, methanol (m/z = 32), CO2 (m/ z = 44) and potassium formate (m/z = 84) were confirmed by FTIR, which also showed the presence of a high amount of carbonate in the methane oxidation products of the ADMEFC with Pd50Ni50/C as the anode catalyst. Tests in ADMEFCs showed that the dependence of the maximum power density on nickel content in the catalysts goes through a maximum value of 13.5 lW cm 2 at 50 at% Ni. Moreover, the amount of produced methanol decreases with increasing Ni content in the PdNi/C catalysts. Both these results can be explained by the enhanced methanol oxidation in the presence of nickel.

    Palavras-Chave: electrocatalysts; fcc lattices; methane; nickel; palladium; methanol; fuel cells; direct methanol fuel cells; alkaline electrolyte fuel cells; greenhouse gases

    Icon

  • IPEN-DOC 27141

    AMARAL, MARCELLO M.; DEL-VALLE, MATHEUS; RAELE, MARCUS P. ; DE PRETTO, LUCAS R. ; ANA, PATRICIA A.. Osteoporosis evaluation through full developed speckle imaging. Journal of Biophotonics, v. 13, n. 7, p. 1-9, 2020. DOI: 10.1002/jbio.202000025

    Abstract: Osteoporosis is a disease characterized by bone mineral density reduction, weakening the bone structure. Its diagnosis is performed using ionizing radiation, increasing health risk. Optical techniques are safer, due to non-ionizing radiation use, but limited to the analyses of bone tissue. This limitation may be circumvented in the oral cavity. In this work we explored the use of laser speckle imaging (LSI) to differentiate the sound and osteoporotic maxilla andmandible bones in an in vitro model. Osteoporosis lesions were simulated with acid attack. The samples were evaluated by optical profilometry and LSI, using a custom software. Two image parameters were evaluated, speckle contrast ration and patches ratio. With the speckle contrast ratio, it was possible to differentiate sound from osteoporotic tissue. From speckle patches ratio it was observed a negative correlation with the roughness parameter. LSI is a promissory technique for assessment of osteoporosis lesions on alveolar bone.

    Palavras-Chave: osteoporosis; lasers; images; laser radiation; skeleton; bone tissues; diagnosis; optical properties; ionizing radiations; bone mineral density; statistical models; statistical models

    Icon

  • IPEN-DOC 27139

    TORRES, LARISSA H.; REAL, CAROLINE C.; TURATO, WALTER M.; SPELTA, LÍDIA W.; DURÃO, ANA C.C. dos S.; ANDRIOLI, TATIANA C.; POZZO, LORENA ; SQUAIR, PETERSON L. ; PISTIS, MARCO; FARIA, DANIELE de P.; MARCOURAKIS, TANIA. Environmental tobacco smoke during the early postnatal period of mice interferes with brain 18F-FDG uptake from infancy to early adulthood: a longitudinal study. Frontiers in Neuroscience, v. 14, p. 1-11, 2020. DOI: 10.3389/fnins.2020.00005

    Abstract: Exposure to environmental tobacco smoke (ETS) is associated with high morbidity and mortality, mainly in childhood. Our aim was to evaluate the effects of postnatal ETS exposure in the brain 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) uptake of mice by positron emission tomography (PET) neuroimaging in a longitudinal study. C57BL/6J mice were exposed to ETS that was generated from 3R4F cigarettes from postnatal day 3 (P3) to P14. PET analyses were performed in male and female mice during infancy (P15), adolescence (P35), and adulthood (P65). We observed that ETS exposure decreased 18F-FDG uptake in the whole brain, both left and right hemispheres, and frontal cortex in both male and female infant mice, while female infant mice exposed to ETS showed decreased 18F-FDG uptake in the cerebellum. In addition, all mice showed reduced 18F-FDG uptake in infancy, compared to adulthood in all analyzed VOIs. In adulthood, ETS exposure during the early postnatal period decreased brain 18FFDG uptake in adult male mice in the cortex, striatum, hippocampus, cingulate cortex, and thalamus when compared to control group. ETS induced an increase in 18F-FDG uptake in adult female mice when compared to control group in the brainstem and cingulate cortex. Moreover, male ETS-exposed animals showed decreased 18F-FDG uptake when compared to female ETS-exposed in the whole brain, brainstem, cortex, left amygdala, striatum, hippocampus, cingulate cortex, basal forebrain and septum, thalamus, hypothalamus, and midbrain. The present study shows that several brain regions are vulnerable to ETS exposure during the early postnatal period and these effects on 18F-FDG uptake are observed even a long time after the last exposure. This study corroborates our previous findings, strengthening the idea that exposure to tobacco smoke in a critical period interferes with brain development of mice from late infancy to early adulthood.

    Palavras-Chave: tobacco; tobacco smokes; nicotiana; environment; image processing; positron computed tomography; uptake; fluorodeoxyglucose; mice; glucose; longitudinal momentum; brain; children; nerve cells

    Icon

  • IPEN-DOC 27138

    OLIVEIRA, J.R.B.; MORALLES, M. ; FLECHAS, D.; CARBONE, D.; CAVALLARO, M.; TORRESI, D.; ACOSTA, L.; AGODI, C.; AMADOR-VALENZUELA, P.; BONANNO, D.; BORELLO-LEWIN, T.; BRISCHETTO, G.A.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CAPPUZZELLO, F.; CHAVEZ-LOMELÍ, E.R.; CIRALDO, I.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GALLO, G.; GUAZZELLI, M.A.; HACISALIHOGLU, A.; IAZZI, F.; LINARES, R.; LO PRESTI, D.; MA, J.; MEDINA, N.H.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; REITO, S.; RIES, P.; RUSSO, G.; SGOUROS, O.; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; SPATAFORA, A.; TUDISCO, S.; WANG, J.S.; YANG, Y.Y.; YILDIRIM, A.; ZAGATTO, V.A.B.. First comparison of GEANT4 hadrontherapy physics model with experimental data for a NUMEN project reaction case. European Physical Journal A, v. 56, n. 5, p. 1-9, 2020. DOI: 10.1140/epja/s10050-020-00152-6

    Abstract: Gamma-ray and neutron spectra from the 18O +76Se reaction at 15.3 MeV/u were measured with the EDEN array of liquid scintillators at the LNS. The results were compared to GEANT Hadrontherapy physics list simulations in order to assess the reliability of this model for the development of theNUMENproject.Agood agreement with the shape of the experimental gamma-ray spectra and a reasonable agreement with the total count rates were obtained. The gamma spectra originated from the nuclear reactions were selected by time coincidence with the Superconducting Cyclotron radio-frequency reference signal. The random coincidence background rate was appropriately described only when the Faraday Cup, the material and geometry of the experimental hall and its contents were included in the simulationwith sufficient detail. The information on the radiation spectra is important for the adequate development of the project of the detector arrays and electronic equipment for the advanced phase of NUMEN. Since orders of magnitude larger beam intensities are planned for this phase, the random coincidence rate is also of significant importance, particularly for the performance of the G-NUMEN gamma calorimeter array.

    Palavras-Chave: angular distribution; beam monitoring; coincidence spectrometry; computerized simulation; counting rates; energy spectra; external beam radiation therapy; faraday cups; g codes; gamma radiation; gamma spectra; gamma spectroscopy; mev range 100-1000; neutron spectra; neutrons; oxygen 18 beams; oxygen 18 reactions; selenium 76 target

    Icon

  • IPEN-DOC 27135

    LOCOSSELLI, GIULIANO M.; MOREIRA, TIANA C.L.; CHACON-MADRID, KATHERINE; ARRUDA, MARCO A.Z.; CAMARGO, EVELYN P. de; KAMIGAUTI, LEONARDO Y.; TRINDADE, RICARDO I.F. da; ANDRADE, MARIA de F.; ANDRE, CARMEN D.S. de; ANDRE, PAULO A. de; SINGER, JULIO M.; SAIKI, MITIKO ; ZACCARELLI-MARINO, MARIA A.; SALDIVA, PAULO H.N.; BUCKERIDGE, MARCOS S.. Spatial-temporal variability of metal pollution across an industrial district, evidencing the environmental inequality in São Paulo. Environmental Pollution, v. 263, Part A, p. 1-8, 2020. DOI: 10.1016/j.envpol.2020.114583

    Abstract: Although air pollution decreased in some cities that shifted from an industrial to a service-based economy, and vehicular emission regulation became more restrictive, it is still a major risk factor for mortality worldwide. In central S~ao Paulo, Brazil, air quality monitoring stations and tree-ring analyses revealed a decreasing trend in the concentrations of particulate matter and metals. Such trends, however, may not be observed in industrial districts located in the urban periphery, where the usual mobile sources may be combined with local stationary sources. To evaluate environmental pollution in an industrial district in southeastern S~ao Paulo, we assessed its spatial variability, by measuring magnetic properties and concentrations of Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, P, S, Sr, Zn in the bark of 62 trees, and its temporal trends, by measuring Cd, Cu, Ni, Pb, V, Zn in tree rings of three trees. Source apportionment analysis based on tree barks revealed two clusters with high concentrations of metals, one related to vehicular and industrial emissions (Al, Ba, Cu, Fe, Zn) in the east side of the industrial cluster, and the other related to soil resuspension (Cu, Zn, Mn) in its west side. These patterns are also supported by the magnetic properties of bark associated with iron oxides and titanium-iron alloy concentrations. Dendrochemical analyses revealed that only the concentrations of Pb consistently decreased over the last four decades. The concentrations of Cd, Cu, Ni, V, and Zn did not significantly decrease over time, in contrast with their negative trends previously reported in central S~ao Paulo. This combined biomonitoring approach revealed spatial clusters of metal concentration in the vicinity of this industrial cluster and showed that the local population has not benefited from the decreasing polluting metal concentrations in the last decades.

    Palavras-Chave: pollution; air pollution; air pollution monitoring; trees; bark; tree rings; microanalysis; vehicles; gaseous wastes; environmental impacts; brazil

    Icon

  • IPEN-DOC 27134

    PELEGRINO, MILENA T.; KOHATSU, MARCIO Y.; SEABRA, AMEDEA B.; MONTEIRO, LUCILENA R. ; GOMES, DIEGO G.; OLIVEIRA, HALLEY C.; ROLIM, WALLACE R.; JESUS, TATIANE A. de; BATISTA, BRUNO L.; LANGE, CAMILA N.. Effects of copper oxide nanoparticles on growth of lettuce (Lactuca sativa L.) seedlings and possible implications of nitric oxide in their antioxidative defense. Environmental Monitoring and Assessment, v. 192, n. 4, p. 1-14, 2020. DOI: 10.1007/s10661-020-8188-3

    Abstract: Copper oxide nanoparticles (CuO NPs) have been extensively explored for use in agriculture. Previous studies have indicated that application of CuO NPs might be promising for development and conservation of plants, pest control, and for the recovery of degraded soils. However, depending on the applied concentration copper can cause phytotoxic effects. In this work, biosynthesized CuO NPs (using green tea extract) were evaluated on their effects on lettuce (Lactuca sativa L.) seedling growth, which were exposed at concentrations ranged between 0.2 and 300 μg mL−1. From the biosynthesized were obtained ultra-small CuO NPs (~ 6.6 nm), with high stability in aqueous suspension. Toxicity bioassays have shown that at low concentrations (up to 40 μg mL−1), CuO NPs did not affect or even enhanced the seed germination. At higher concentrations (higher than 40 μg mL−1), inhibition of seed germination and radicle growth ranging from 35 to 75% was observed. With the increase of CuO NPs concentrations, nitrite and S-nitrosothiols levels in radicles increased, whereas superoxide dismutase and total antioxidant activities decreased. The nitrite and Snitrosothiols levels in lettuce radicles showed a direct dose response to CuO NP application, which may indicate nitric oxide-dependent signaling pathways in the plant responses. Therefore, the results demonstrated that at low concentrations (≤ 20 μg mL−1) of CuO NPs, beneficial effects are obtained from seedlings, enhancing plant growth, and the involvement of nitric oxide signaling in the phytotoxic effects induced by high concentration of this formulation.

    Palavras-Chave: copper oxides; nanoparticles; lettuce; toxicity; bioassay; plants; seeds; beverages; metals

    Icon

  • IPEN-DOC 27133

    COUTO, CAMILA P. ; REVILLA, REYNIER I.; COLOSIO, MARCO A.; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; DE GRAEVE, IRIS; TERRYN, HERMAN; ROSSI, JESUALDO L. . Electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si before and after hot-stamping process investigated by means of scanning Kelvin probe microscopy. Corrosion Science, v. 174, p. 1-10, 2020. DOI: 10.1016/j.corsci.2020.108811

    Abstract: Press-hardened steels are commonly protected with hot-dip Al-Si coating. Due to the electrochemical complexity of this system, either before or after hot-stamping process, SKPFM was used to investigate the influence of the thermo-mechanical process on the electrochemical behaviour of the galvanic coupling. The hot-stamping process changed significantly the anodic/cathodic coupling of the coating/steel due to iron enrichment in the coating layer. Hence, a concurrent mechanism was thoroughly established, i.e., while the press hardening enhances the corrosion properties of the steel system (steel and metallic coating) through diffusion, at the same time it diminishes the cathodic protection of the Al-Si layer.

    Palavras-Chave: steels; hardness; coupling; electrochemical corrosion; surface coating; coatings; electron scanning; scanning electron microscopy; electrochemical coating

    Icon

  • IPEN-DOC 27132

    COELHO, EDNEI; REIS, TATIANA A.; COTRIM, MARYCEL ; MULLAN, THOMAS K.; CORREA, BENEDITO. Resistant fungi isolated from contaminated uranium mine in Brazil shows a high capacity to uptake uranium from water. Chemosphere, v. 248, p. 1-9, 2020. DOI: 10.1016/j.chemosphere.2020.126068

    Abstract: The Osamu Utsumi uranium mine occupies a 20 km2 area in the city of Caldas, which is located in the state of Minas Gerais, Brazil. Since mining activities ended at Osamu Utsumi 24 years ago, the surrounding area has become contaminated by acid effluents containing high concentrations of uranium. Thus, the aim of this study was to assess the uranium bioremediation capacity of 57 fungi isolated from the mine area. In tolerance tests, 38% (22) of the fungal isolates were considered tolerant to uranium, including 10 Penicillium species. At a uranium concentration of 2000 mg L 1 48 fungi did not exhibit mycelial growth index inhibition. Minimal inhibitory concentration (MIC) analysis showed growth of 25 fungi above a uranium concentration of 8000 mg L 1. At high uranium concentrations, some fungi (i.e., Talaromyces amestolkiae and Penicillium citrinum) showed morphological changes and pigment (melanin) production. Among the fungal isolates, those considered to be more tolerant to uranium were isolated from soil and sediment samples containing higher concentrations of heavy metal. When comparing the results of resistance/tolerance tests with those for uranium biosorption capacity, we concluded that the fungi isolated from the Osamu Utsumi mine with the best potential for uranium bioremediation were Gongronella butleri, Penicillium piscarium, Penicillium citrinum, Penicillium ludwigii, and Talaromyces amestolkiae. Biosorption tests with live fungal biomass showed that 11 species had a high potential for uranium uptake from contaminated water.

    Palavras-Chave: uranium mines; bioremediation; fungi; water; scanning electron microscopy; bioadsorbents; biomass; osamu utsumi mine

    Icon

  • IPEN-DOC 27131

    DUARTE, LUIS F. de A.; BLASCO, JULIAN; CATHARINO, MARILIA G.M. ; MOREIRA, EDSON G. ; TROMBINI, CHIARA; NOBRE, CAIO R.; MORENO, BEATRIZ B.; ABESSA, DENIS M. de S.; PEREIRA, CAMILO D.S.. Lead toxicity on a sentinel species subpopulation inhabiting mangroves with different status conservation. Chemosphere, v. 251, p. 1-13, 2020. DOI: 10.1016/j.chemosphere.2020.126394

    Abstract: Lead is a priority pollutant introduced in the aquatic environment by different sources commonly located in estuarine regions, such as ports, marinas and industries. Environmental agencies around the world set the maximum allowable concentration of lead in effluents, surface water and sediment, but few studies reported its accumulation and chronic toxicity in mangrove benthic invertebrates using concentrations believed to be safe. In the case of Brazilian mangrove environments, Ucides cordatus is a crab species of choice to be used in bioaccumulation studies. We have assessed biomarkers’ responses (DNA strand breaks, micronucleated cells, metallothioneins, enzymatic activity of aminolevulinic acid dehydratase and neutral red retention time) and the total bioaccumulation in six tissues of U. cordatus crabs resident to mangrove areas under different conservation status during a 28-day period bioassay. We also investigated Pb subcellular partition and biomarkers’ responses using a supposedly safe concentration (10 mg L 1). During the Pb exposure, the highest concentration of Pb was observed in crab gills. Crabs also showed a high ability to allocate Pb in detoxified forms. Multivariate analysis pointed out that bioaccumulation (total, active and detoxified) is linked to biomarkers. Even in supposedly safe dosage, U. cordatus triggered its defense mechanisms expressing more metallothioneins and presented relevant cyto-genotoxic damage. Our data suggest the development of biological tolerance to Pb in crabs from polluted areas. Our results provided a new insight about lead toxicity even at concentrations considered environmentally safe, which could support new strategies to manage estuarine areas considering their respective conservation status.

    Palavras-Chave: lead; toxicity; environment; biological accumulation; subcellular distribution; metals; partition; mangroves; crabs; aquatic ecosystems; resource conservation; environmental protection

    Icon

  • IPEN-DOC 27130

    RICHARD, DIEGO; RENTERÍA, MARIO; CARBONARI, ARTUR W. ; ROMERO, MARIANO; FACCIO, RICARDO. Preparation of In-doped Y2O3 ceramics through a sol-gel process: effects on the structural and electronic properties. Ceramics International, v. 46, n. 10, p. 16088-16095, 2020. DOI: 10.1016/j.ceramint.2020.03.161

    Abstract: The Pechini-type sol-gel (PSG) process has been used for the preparation of doped oxides due to its capability to overcome most of the difficulties that frequently occur by using other producing methods. In this work we analyze the case of samples of pure and In-doped yttria (Y2O3) prepared by the PSG process. We experimentally characterize the synthesized samples by x-ray diffraction, micro-Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and time-differential perturbed γ-γ angular correlation (PAC) spectroscopy, and we compare these results with those obtained starting from commercial oxide powders. We found that the PSG process can be used to successfully produce doped yttria in the cubic phase, with the impurities substitutionally located at the cationic sites of the structure. By the proposed PSG route, the inclusion of impurities does not affect the particle size nor the resistivity. However, when we compare the PSG samples with other samples produced from commercial powder, we found that the first have lower resistivities at grain interiors. On the other hand, PAC spectroscopy in 111In(→111Cd)-doped yttria allows the study of the dynamic hyperfine interactions observed by the radioactive 111Cd impurity-probe, which can be used to “sense” the host electron availability near the impurities after the electron-capture decay of 111In. Differences between PAC spectra for PSG samples and the commercial powder suggest that the PSG process introduces additional donor defects into the yttria electronic structure, which is consistent with the lower resistivity observed in the PSG samples by EIS spectroscopy.

    Palavras-Chave: oxides; impurities; semiconductor materials; ceramics; sol-gel process; doped materials; crystal doping; electrochemistry; impedance; hyperfine structure; interactions; raman spectra; spectroscopy; perturbed angular correlation

    Icon

  • IPEN-DOC 27129

    BERTOLETE, M.; BARBOSA, P.A. ; ROSSI, WAGNER de ; FREDERICCI, C.; MACHADO, I.F.. Mechanical characterisation and machining evaluation of ceramic cutting tools functionally graded with six layers. Ceramics International, v. 46, n. 10, p. 15137-15145, 2020. DOI: 10.1016/j.ceramint.2020.03.048

    Abstract: Functionally graded materials (FGMs) are composites graded in one or more directions by the mean volume fraction variation of their constituents in a continuous or stepwise design. The objective of this study is to apply the FGM concept to ceramic cutting tools to widen its application range. Thus, two cutting tool materials were selected: cemented carbide, owing to its higher toughness, and alumina-based ceramic, owing to its high wear resistance at elevated temperatures. Ceramics based on alumina were functionally graded with cemented carbide and sintered using the spark plasma sintering technique. The thermal residual stresses were predicted; additionally, the microstructure, relative density, and Vickers hardness and fracture toughness for the alumina layer were evaluated, and flexural strength and machining tests were conducted. From the results, cracks were not observed in the microstructure and full density was obtained. In general, the hardness and fracture toughness values were close to those in the literature. A flexural strength improvement of at least 50% on FGM samples was observed in comparison to homogeneous ceramic ones. The FGM cutting tools supported approximately 1000 N of machining force without catastrophic failure when turning martensitic stainless steel into a conventional lathe. The values of surface roughness (Ra and Rz) agree with those in the literature under similar cutting and geometry conditions.

    Palavras-Chave: cutting tools; machining; mechanical properties; sintering; ceramics; stainless steels; microstructure; evaluation

    Icon

  • IPEN-DOC 27128

    VIEIRA, LAÍS H.S.; SABINO, CARLA M.S.; SOARES JÚNIOR, FRANCISCO H.; ROCHA, JANAINA S.; CASTRO, MANUELA O.; ALENCAR, RAFAEL S.; COSTA, LUELC S. da; VIANA, BARTOLOMEU C.; PAULA, AMAURI J. de; SOARES, JOAO M.; SOUZA FILHO, ANTONIO G.; OTUBO, LARISSA ; FECHINE, PIERRE B.A.; GHOSH, ANUPAMA; FERREIRA, ODAIR P.. Strategic design of magnetic carbonaceous nanocomposites and its application as multifunctional adsorbent. Carbon, v. 161, p. 758-771, 2020. DOI: 10.1016/j.carbon.2020.01.089

    Abstract: Magnetic carbonaceous nanocomposites (MCN) were prepared by hydrothermal carbonization (HTC) of a carbohydrate in the presence of Fe3þ, followed by thermal treatment with KOH for simultaneous activation and magnetization. The precursor formed (IOCN) in the HTC process contained iron oxide nanoparticles encapsulated in the hydrochar matrix. The thermochemical parameters of the activation (temperature and IOCN/KOH mass-ratio) were varied to achieve an increase of the specific surface area along with formation of magnetic phases in MCN compared to IOCN. Activation temperature was found to be responsible for the structural and morphological properties of the MCNs whereas the IOCN/KOH mass-ratio controlled the porosity. The magnetic properties of the MCNs originated from the formation of Fe3O4 and Fe0 phases, which are encapsulated in the carbonaceous material. The MCNs were tested for adsorption of methylene blue (MB) dye, followed by magnetic separation. The MCN, produced in the optimized conditions, showed a specific surface area of 766 m2 g 1, magnetization of 8 emu g 1 and a MB adsorption capacity of 570 mg g 1. Detailed kinetic and isotherm studies of MB adsorption were also performed. The methodology of simultaneous activation and magnetization to generate MCNs, presented here, could be extended to obtain new multifunctional carbon-based nanocomposite adsorbent starting from different biomasses.

    Palavras-Chave: nanocomposites; carbonaceous materials; magnetic materials; magnetic fields; iron oxides; hydrothermal systems; adsorbents; carbon

    Icon

  • IPEN-DOC 27127

    BORDON, ISABELLA C.; JOVIANO, WILLIAN R.; MEDEIROS, ALINE M.Z. de; CAMPOS, BRUNO G. de; ARAUJO, GIULIANA S. de; GUSSO-CHOUERI, PALOMA K.; PRETO, MAYRA de F.; FAVARO, DEBORAH I.T. ; ABESSA, DENIS M. de S.. Heavy metals in tissues of blue crabs Callinectes danae from a subtropical protected estuary influenced by mining residues. Bulletin of Environmental Contamination and Toxicology, v. 104, n. 4, p. 418-422, 2020. DOI: 10.1007/s00128-020-02815-y

    Abstract: This short note aims to report in detail a preliminary assessment of the concentrations of Cd, Hg and Pb in tissues of blue crabs Callinectes danae collected from the Cananéia-Iguape-Peruíbe estuarine complex (CIP), in the South of São Paulo State coast, Brazil. In October 2014, blue crabs were collected from CIP. Tissues were removed by dissection and metal determination was performed by GF-AAS and CV-AAS. According to statistical analysis, Pb and Cd concentrations in gills were significantly higher than those found in muscles and hepatopancreas, respectively. There were no significant differences in Hg concentrations between samples. Cd, Hg and Pb concentrations in gills and hepatopancreas were lower than those reported in a previous study performed at CIP. However, Cd concentration in hepatopancreas was higher than the Brazilian limit for consumption and new efforts to monitor Cd concentrations in C. danae tissues must be performed.

    Palavras-Chave: crabs; environmental impacts; heavy metals; cadmium; mercury; lead; estuaries; aquatic ecosystems; mineral industry; mining; mines; water pollution; toxicity; ecological concentration; environment

    Icon

  • IPEN-DOC 27126

    DALTOE, FELIPE P.; OLIVEIRA, NÉLIO A.J. de ; PERONI, CIBELE N. ; SHARPE, PAUL T.; MANTESSO, ANDREA. Phenotype changes of oral epithelial stem cells after in vitro culture. Brazilian Oral Research, v. 34, p. 1-8, 2020. DOI: 10.1590/1807-3107bor-2020.vol34.0033

    Abstract: The aim of our study was to isolate populations of keratinocyte stem cells based on the expression of cell surface markers and to investigate whether the culture could affect their phenotype. keratinocytes from human oral mucosa were sorted based on the expression of the epithelial stem cell markers p75NTR and CD71. We also examined the co-expression of other epithelial stem markers such as integrins β1 and α6 and their stem cell-like proprieties in in vitro assays. Three passages after being sorted by MACS, more than 93% of the p75NTR+ve cells lost the expression of p75NTR, while 5.46% of the p75NTR-ve gained it. Within the small population of the p75NTR+ve cells, 88% co-expressed other epithelial stem cell markers such as integrins β1 and α6, while only 28% of p75NTR-ve cells co-expressed these markers. These results were confirmed by sorting cells by FACS. Additionally, when double staining was used for sorting cells, 99% of the p75NTR+veCD71-ve and 33% of the p75NTR-veCD71+ve cells expressed both integrins, but just one week after culture, only 1.74% of the p75NTR+veCD71-ve cells still expressed p75NTR and only 0.32% still expressed CD71. Similar results were obtained when co-culturing p75NTR+ve and p75NTR-ve populations before analysis. Our results suggest that phenotype changes may be part of an intrinsic cellular mechanism to conserve levels of protein expression as they may found in the human body. In addition, in vitro culture may not offer ideal conditions for epithelial stem cell maintenance due to phenotype changes under standard culture conditions.

    Palavras-Chave: stem cells; phenotype; mucous membranes; oral cavity; epithelium; animal cells; animal tissues; cell cultures; in vitro

    Icon

  • IPEN-DOC 27125

    BELLEZZO, MURILLO ; FONSECA, GABRIEL P.; VONCKEN, ROBERT; VERRIJSSEN, AN-SOFIE; VAN BEVEREN, CELINE; ROELOFS, ERIK; YORIYAZ, HELIO ; RENIERS, BRIGITTE; VAN LIMBERGEN, EVERT J.; BERB EE, MAAIKE; VERHAEGEN, FRANK. Advanced design, simulation, and dosimetry of a novel rectal applicator for contact brachytherapy with a conventional HDR 192Ir source. Brachytherapy, v. 19, n. 4, p. 544-553, 2020. DOI: 10.1016/j.brachy.2020.03.009

    Abstract: PURPOSE: Dose escalation yields higher complete response to rectal tumors, which may enable the omission of surgery. Dose escalation using 50 kVp contact x-ray brachytherapy (CXB) allow the treatment of a selective volume, resulting in low toxicity and organs-at-risk preservation. However, the use of CXB devices is limited because of its high cost and lack of treatment planning tools. Hence, the MAASTRO applicator (for HDR 192Ir sources) was developed and characterized by measurements and Monte Carlo simulations to be a cost-effective alternative to CXB devices. METHODS AND MATERIALS: A cylindrical applicator with lateral shielding was designed to be used with a rectoscope using its tip as treatment surface. Both the applicator and the rectoscope have a slanted edge to potentially allow easier placement against tumors. The applicator design was achieved by Monte Carlo modeling and validated experimentally with film dosimetry, using the Papillon 50 (P50) device as reference. RESULTS: The applicator delivers CXB doses in less than 9 min using a 20375 U source for a treatment area of approximately 20 20 mm2 at 2 mm depth. Normalized at 2 mm, the dose falloff for depths of 0 mm, 5 mm, and 10 mm are 130%, 70%, and 43% for the P50 and 140%, 67%, and 38% for the MAASTRO applicator, respectively. CONCLUSIONS: The MAASTRO applicator was designed to use HDR 192Ir sources to deliver a dose distribution similar to those of CXB devices. The applicator may provide a cost-effective solution for endoluminal boosting with clinical treatment planning system integration.

    Palavras-Chave: brachytherapy; monte carlo method; rectal administration; iridium 192; dose rates; radiation sources; simulation; radiotherapy; neoplasms; film dosimetry

    Icon

  • IPEN-DOC 27124

    COURROL, LILIA C.; ESPINOZA-CULUPÚ, ABRAHAM; SILVA JUNIOR, PEDRO I. da; GONÇALVES, KARINA de O.; SILVA, FLAVIA R. de O. ; BORGES, MONAMARIS M.. Antibacterial and antitumoral activities of the spider acylpolyamine Mygalin silver nanoparticles. BioNanoScience, v. 10, n. 2, p. 463-472, 2020. DOI: 10.1007/s12668-020-00738-w

    Abstract: Mygalin is a synthetic analog of polyamine spermidine isolated from spider hemocytes. Polyamines show potential therapeutic activity against a wide range of human diseases such as cancer and microbial infections. In this work, we analyzed the antibacterial and antitumoral activities of Mygalin silver nanoparticles synthesized by the photoreduction method. The formation and distribution of MygAgNPs were confirmed by UV-visible spectroscopy, zeta potential, and transmission electron microscopy. The obtained nanoparticles were mostly spherical with a particle size distribution in the range of ~ 10–60 nm. We have demonstrated that MygAgNPs increased the effectiveness of the native Mygalin by approximately 6400-fold. Cytotoxicity tests were performed, and it was possible to reach a concentration that was not toxic to healthy cells (NHI-3T3) and at the same time toxic to the tumor cell line (MCF-7). The obtained results suggest that this system shows potential enhanced antibacterial activity against Escherichia coli, DH5α and anticancer activity against MCF-7 cell line.

    Palavras-Chave: drugs; neoplasms; antibiotics; spiders; silver; nanoparticles; cell cultures; drugs; amines; bacteria

    Icon

  • IPEN-DOC 27123

    MOREIRA, GREGORI de A. ; GUERRERO-RASCADO, JUAN L.; BRAVO-ARANDA, JUAN A.; FOYO-MORENO, INMACULADA; CAZORLA, ALBERTO; ALADOS, INMACULADA; LYAMANI, HASSAN; LANDULFO, EDUARDO ; ALADOS-ARBOLEDAS, LUCAS. Study of the planetary boundary layer height in an urban environment using a combination of microwave radiometer and ceilometer. Atmospheric Research, v. 240, p. 1-15, 2020. DOI: 10.1016/j.atmosres.2020.104932

    Abstract: The Planetary Boundary Layer (PBL) is an important part of the atmosphere that is relevant in different atmospheric fields like pollutant dispersion, and weather forecasting. In this study, we analyze four and five-year datasets of measurements gathered with a ceilometer and a microwave radiometer to study the PBL structure respectively, in the mid-latitude urban area of Granada (Spain). The methodologies applied for the PBL Height (PBLH) detection (gradient method for ceilometer and the combination of parcel method and temperature gradient method for microwave radiometer) provided a description in agreement with the literature about the PBL structure under simple scenarios. Then, the PBLH behavior is characterized by a statistical study of the convective and stable situations, so that the PBLH was obtained from microwave radiometer measurements. The analysis of the PBLH statistical study shows some agreement with other PBLH studies such as daily pattern and yearly cycle, and the discrepancies were explained in terms of distinct latitudes, topography and climate conditions. Finally, it was performed a joint long-term analysis of the residual layer (RL) provided by ceilometer and the stable and convective layer heights determined by microwave radiometer, offering a complete picture of the PBL evolution by synergetic combination of remote sensing techniques. The PBL behavior has been used for explaining the daily cycle of Black Carbon (BC) concentration, used as tracer of the pollutants emissions associated to traffic.

    Palavras-Chave: boundary layers; urban areas; atmospheres; clouds; microwave radiation; radiometers; weather; cloud cover; remote sensing; climates; monitoring

    Icon

  • IPEN-DOC 27122

    DAFRÉ-MARTINELLI, MARCELLE; FIGUEIREDO, ANA M.G. ; DOMINGOS, MARISA. Trace element leaf accumulation in native trees from the remaining Semideciduous Atlantic Forest in Brazil. Atmospheric Pollution Research, v. 11, n. 5, p. 871-879, 2020. DOI: 10.1016/j.apr.2020.01.015

    Abstract: Remnants of Semideciduous Atlantic Forest surrounded by numerous industries, intense road traffic and agricultural lands in Southeast Brazil have been affected by trace elements. We implemented a passive biomonitoring with the three most abundant native tree species (Astronium graveolens, Croton floribundus and Piptadenia gonoacantha) to answer these questions: 1) which species has the greatest potential to accumulate trace elements?; 2) does the leaf accumulation level of trace elements vary between the edge and interior of the forest remnants, between dry and wet periods or due to the distance from the industrial area?; 3) which species, among the most abundant in the forest remnants, would better indicate the spatial variations in trace elements pollution and which elements would be the most relevant for such spatial discrimination? Leaf samples were collected during the dry and wet seasons, at the edge and interior of four forest remnants. Trace elements were determined using inductively coupled plasma mass spectrometry (ICP MS). Few edge effects were evidenced in the leaf concentrations in all species. Higher concentrations of most trace elements were measured during dry season. Although C. floribundus showed the most accumulating capacity, A. graveolens was the most appropriate species to discriminate spatial variations. The forest closer to the industrial area was distinguished from the others by Mn and Ni from oil burning, but the metal pollution from the industrial area did not interfere on the leaf concentrations in A. graveolens sampled in the urban and rural forests.

    Palavras-Chave: air pollution; particulates; deposition; air pollution monitoring; biological indicators; trace amounts; elements; forests; brazil; trees; monitoring; leaves; environment; mass spectroscopy; plasma

    Icon

  • IPEN-DOC 27121

    ARAUJO, G.S.; GUSSO-CHOUERI, P.K.; FAVARO, D.I.T. ; ROCHA, R.C.C.; SAINT'PIERRE, T.D.; HAUSER-DAVIS, R.A.; BRAZ, B.; SANTELLI, R.E.; FREIRE, A.S.; MACHADO, W.T.V.; CRUZ, A.C.F.; ABESSA, D.M.S.. Metal‑associated biomarker responses in crabs from a marine protected area in Southeastern Brazil. Archives of Environmental Contamination and Toxicology, v. 78, n. 3, p. 463-477, 2020. DOI: 10.1007/s00244-020-00710-5

    Abstract: The environmental quality of a Ramsar wetland site located at the Cananéia-Iguape-Peruíbe Protected Area (CIP-PA), in São Paulo, Brazil, was assessed by geochemical analyses and biomarker assessments (GPx, GST, GSH, GST, MT, LPO, DNA damage) performed in swimming crab Callinectes danae Smith, 1869 organs (posterior and anterior gills and hepatopancreas) to estimate sediment contaminant bioavailability. The results indicated that two sampling stations, PT and PM, exhibited the worst environmental conditions, as sediments collected at both points contained metal contamination, while crabs exhibited significant responses for GPx, GST, and LPO (mostly during winter). Sediment contamination tended to be associated to fine sediments (both seasons) and organic matter (winter). During the summer survey, Pb concentrations in sediments of station PT exceeded the Brazilian Sediment Quality Guidelines (SQGs) and the Canadian Interim Marine Sediment Quality Guidelines. Metal concentrations in sediments sampled in winter were higher compared with summer, with Co, Ni, and Pb exceeding SQGs levels at PT, whereas Co, Ni, Hg, Zn, and Pb exceeded SQGs at PM. Biomarker induction during summer appeared to be caused by natural variables (water salinity and temperature, and molting cycle), whereas oxidative stress and tissue damage during winter appeared to be more clearly linked to metal contamination. Anterior gills presented the clearest signs of seasonal variability, being more responsive to sediment contamination. The results suggest that metals originated from the upper Ribeira de Iguape River are transported toward the estuarine system, causing effects on C. danae individuals. Additionally, seasonality is a strong factor concerning CIP-PA toxicity, since the rainfall regime significantly modifies the freshwater flow and, consequently, estuarine water salinity, suspended particle and metal inputs, as well as the location of depositional areas. Thus, efforts to mitigate CIP-PA contamination should be based on the control of upstream pollution sources.

    Palavras-Chave: crabs; sediments; sampling; biological markers; environmental materials; aquatic ecosystems; environment; water pollution monitors; metals; ecological concentration; chemical analysis; nature reserves

    Icon

  • IPEN-DOC 27120

    CASTRO, PEDRO A.A. ; LIMA, CASSIO A. ; MORAIS, MYCHEL R.P.T.; ZORN, TELMA M.T.; ZEZELL, DENISE M. . Monitoring the progress and healing status of burn wounds using infrared spectroscopy. Applied Spectroscopy, v. 74, n. 7, p. 758-766, 2020. DOI: 10.1177/0003702820919446

    Abstract: Burns are one of the leading causes of morbidity worldwide and the most costly traumatic injuries. A better understanding of the molecular mechanisms in wound healing is required to accelerate tissue recovery and reduce the health economic impact. However, the standard techniques used to evaluate the biological events associated to wound repair are laborious, time-consuming, and/or require multiple assays/staining. Therefore, this study aims to evaluate the feasibility of Fourier transform infrared (FT-IR) spectroscopy to monitor the progress and healing status of burn wounds. Burn injuries were induced on Wistar rats by water vapor exposure and biopsied for further histopathological and spectroscopic evaluation at four time-points (3, 7, 14, and 21 days). Spectral data were preprocessed and compared by principal component analysis. Pairwise comparison of post-burn groups to each other revealed that metabolic activity induced by thermal injury decreases as the healing progresses. Higher amounts of carbohydrates, proteins, lipids, and nucleic acids were evidenced on days 3 and 7 compared to healthy skin and reduced amounts of these molecular structural units on days 14 and 21 postburn. FT-IR spectroscopy was used to determine the healing status of a wound based on the biochemical information retained by spectral signatures in each phase of healing. Our findings demonstrate that FT-IR spectroscopy can monitor the biological events triggered by burn trauma as well as to detect the wound status including full recovery based on the spectral changes associated to the biochemical events in each phase.

    Palavras-Chave: infrared spectrometers; spectroscopy; wounds; burns; healing; histological techniques; animal tissues; chemical analysis

    Icon

  • IPEN-DOC 27119

    SILVA JÚNIOR, IREMAR A. da ; SIQUEIRA, PAULO de T.D. ; NASCIMENTO, EDUARDO do; YORIYAZ, HELIO ; SORDI, GIAN-MARIA A.A. ; POTIENS, MARIA da P.A. . Variability: surface intensity distribution of large-area reference sources. Applied Radiation and Isotopes, v. 160, p. 1-7, 2020. DOI: 10.1016/j.apradiso.2020.109108

    Abstract: In this paper we present the impact of variability, a surface source parameter, on the efficiency evaluation of surface contamination monitors. This study was based on two source uniformity correction methodologies and data from real surface source distributions. Surface source intensity distribution has been changed by rearranging the cells (portions of the active area of each LARS) while keeping the same source uniformity value. Instrument efficiencies have been calculated for different sets of uniformities and variabilities. This study led to emphasize the importance of variability, a differential source intensity distribution parameter, over the uniformity, an integral source intensity distribution parameter, and reinforced the importance of the source uniformity correction procedure on the course of surface contamination monitor calibration.

    Palavras-Chave: surface contamination; surface contamination monitors; variations; calculation methods; variational methods; radiation sources; calibration; monte carlo method

    Icon

  • IPEN-DOC 27118

    YAMAZAKI, I.M. ; KOSKINAS, M.F. ; MOREIRA, D.S. ; SEMMLER, R. ; BRANCACCIO, F. ; DIAS, M.S. . Primary standardization and determination of gamma ray emission intensities of Ho-166. Applied Radiation and Isotopes, v. 164, p. 1-6, 2020. DOI: 10.1016/j.apradiso.2020.109237

    Abstract: The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN-CNEN/SP, in S~ao Paulo, for the primary standardization of 166Ho is described. The activity of 166Ho was determined by the efficiency extrapolation technique applied to a 4πβ(PC)-γ coincidence system using a gas flow proportional counter in 4π geometry coupled to a 76 x 76 mm NaI(Tl) crystal. The results for the γ-rays intensities at 80.57 and 1379.45 keV were 0.0651(11) and 0.00904(11), respectively.

    Palavras-Chave: standardization; gamma radiation; emission; holmium 166; coincidence methods; counting techniques; four-pi counting; x-ray sources; measuring instruments; radioisotopes

    Icon

  • IPEN-DOC 27117

    SILVA JÚNIOR, IREMAR A. ; SIQUEIRA, PAULO de T.D. ; NASCIMENTO, EDUARDO do; YORIYAZ, HELIO ; SORDI, GIAN-MARIA A.A. ; VIVOLO, VITOR ; POTIENS, MARIA da P.A. . Correction factors for non-uniform large-area reference sources. Applied Radiation and Isotopes, v. 160, p. 1-6, 2020. DOI: 10.1016/j.apradiso.2020.109082

    Abstract: Based on uniformity measurements of large-area reference sources used in calibration procedures of surface contamination monitors, an investigation was carried out to obtain a method that estimates the bias originated from surface source intensity distribution deviation from the ideal uniform distribution and corrects it. It relies on correcting the estimated instrument efficiency by applying correction factors driven from the uniformity distribution profiles of the sources used in calibration procedure. Simulations of the monitor calibration procedure are run for 2 distinct surface source distributions: the real and the ideally uniform distributions. Correction factors are driven from counting rate estimates obtained from each source representation. In order to evaluate adequacy of this proposition it was validated against a method proposed by the NPL in the Good Practices Guide No.14.

    Palavras-Chave: corrections; radiation sources; calibration; monte carlo method; numerical data; surface contamination monitors; measuring methods

    Icon

  • IPEN-DOC 27116

    LECONTE, P.; ARCHIER, P.; DE SAINT JEAN, C.; DINIZ, R. ; SANTOS, ADIMIR dos ; FAUTRAT, L.; FOLIGNO, D.; GESLOT, B.; GILAD, E.; TAMAGNO, P.; TRUCHET, G.; ZOIA, A.. New delayed neutron group constants and covariances for LWR core applications, combining summation calculations and integral experiments. Annals of Nuclear Energy, v. 139, p. 1-9, 2020. DOI: 10.1016/j.anucene.2019.107250

    Palavras-Chave: reactors; neutrons; reactor cores; uranium 235; uranium 238; neutron emission; ipen-mb-1 reactor; reactor noise; minerve reactor

    Icon

  • IPEN-DOC 27115

    CAVALLARO, MANUELA; ACOSTA, LUIS; AGODI, CLEMENTINA; ALTANA, CARMEN; AMADOR-VALENZUELA, PAULINA; AUERBACH, NAFTALI; BAREA, JOSE; BELLONE, JESSICA I.; BIJKER, ROELOF; BONANNO, DANILO; BORELLO-LEWIN, THEREZA; BOZTOSUN, ISMAIL; BRANCHINA, VINCENZO; BRASOLIN, SANDRO; BRISCHETTO, GIUSEPPE A.; BRUNASSO, OSCAR; BURRELLO, STEFANO; CALABRESE, SALVATORE; CALABRETTA, LUCIANO; CALVO, DANIELA; CAPIROSSI, VITTORIA; CAPPUZZELLO, FRANCESCO; CARBONE, DIANA; CHARON GARCIA, LUIS E.; CHÁVEZ LOMELI, EFRAIN R.; CHEN, RUOFU; CIRALDO, IRENE; COLONNA, MARIA; D'AGOSTINO, GRAZIA; DELAUNAY, FRANCK; DESHMUKH, NIKIT; DJAPO, HARIS; DE GERONIMO, GIANLUIGI; DE LOS RÌOS, K.; FERRARESI, CARLO; FERREIRA, JONAS L.; FERRETTI, JACOPO; FINOCCHIARO, PAOLO; FIRAT, SUNA; FISICHELLA, MARIA; FOTI, ANTONINO; GALLO, GIUSEPPE; GARCIA-TECOCOATZI, HUGO; HACISALIHOGLU, AYLIN; HUERTA-HERNANDEZ, ARCADIO; KOTILA, JENNI; KUCUK, YASEMIN; IAZZI, FELICE; LANZALONE, GAETANO; LAY, JOSÉ A.; LA FAUCI, LAURA; LA VIA, FRANCESCO; LENSKE, HORST; LINARES, ROBERTO; LO PRESTI, DOMENICO; LUBIAN, JESUS; MA, JUNBING; MARIN-LÁMBARRI, DANIEL; MAS RUIZ, J.; MEDINA, NILBERTO H.; MENDES, DJALMA R.; MEREU, PAOLO; MORALLES, MAURICIO ; NERI, LORENZO; OLIVEIRA, JOSÉ R.B.; PAKOU, ATHENA; PANDOLA, LUCIANO; PETRASCU, HORIA; PIETRALLA, NORBERT; PINNA, FEDERICO; REITO, SANTO; RIES, PHILIPP C.; RODRIGUES, MARCIA R.D.; RUSSO, ANTONIO D.; RUSSO, GIUSEPPE; SANTOPINTO, ELENA; SANTOS, ROBERTO B.B.; SERBINA, LEONARDO; SGOUROS, ONOUFRIOS; SILVEIRA, MARCILEI A.G. da; SOLAKCI, SELÇUK O.; SOULIOTIS, GEORGE; SOUKERAS, VASILEIOS; SPATAFORA, ALESSANDRO; TORRESI, DOMENICO; TUDISCO, SALVATORE; VARGAS HERNANDEZ, HESIQUIO; VSEVOLODOVNA, RUSLAN I.M.; WANG, JAN S.; WERNER, VOLKER; YANG, YAN Y.; YILDIRIN, AYDIN; ZAGATTO, VINICIUS A.B.. Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS. EPJ Web of Conferences, v. 223, n. 01009, p. 1-5, 2019. DOI: 10.1051/epjconf/201922301009

    Abstract: The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are described.

    Palavras-Chave: double beta decay; neutrinoless double beta decay; heavy ions; nuclear matrix; spectrometers; charge-exchange reactions; nuclear structure; neon 20 beams

    Icon

  • IPEN-DOC 27114

    COUTO, CAMILA P. ; COSTA, ISOLDA ; VIVEIROS, BARBARA V.G. de ; ALENCAR, MAICON C. de ; COLOSIO, MARCO A.; PANOSSIAN, ZEHBOUR; ROSSI, JESUALDO L. . The use of scanning vibrating electrode technique to evaluate the effect of hot stamping on the corrosion resistance of 22MnB5 press-hardened steel electroplated with Zn-Ni. Materials Research, v. 22, suppl. 1, p. 1-6, 2019. DOI: 10.1590/1980-5373-MR-2019-0163

    Abstract: Carmakers must achieve the worldwide targets for lightweight materials, safety and reducing the fuel consumption. The use of press-hardened steel (PHS), in vehicle structures has been contributing with these requirements. This type of steel is widely used for the hot-stamping which consists in heating the steel blank to total austenitization temperature and then transferring it from the furnace into the die tool where the steel is formed and quenched at the same time. PHS is usually protect with metallic coatings in order to avoid both steel oxidation and decarburization. Hot-dip Al-Si coating is currently the main used in this application. However, alternative coatings, like zinc-based, are under investigation. This work aims at evaluating the corrosion resistance of the 22MnB5 grade PHS, electroplated with Zn-Ni, before and after hot stamping, using the scanning vibrating electrode technique (SVET). Results from SVET showed that samples prior to hot stamping, the corrosion mechanism was uniform over the exposed surface, and was mainly related to selective dissolution of zinc from the coating. On the other hand, hot stamped samples showed localized corrosion mechanism with decrease in current with time of immersion due to the formation of corrosion products on the exposed surface.

    Palavras-Chave: coatings; metals; hardening; steels; automotive industry; electrolytes; zinc; nickel; electroplating; corrosion resistance; scanning electron microscopy; backscattering; electrons; corrosion protection

    Icon

  • IPEN-DOC 27113

    MUNAWAR, AISHA; AKREM, AHMED; HUSSAIN, ASHIQ; SPENCER, PATRICK ; BETZEL, CHRISTIAN. Molecular model of cytotoxin-1 from Naja mossambica mossambica venom in complex with chymotrypsin. Theoretical Biology Forum, v. 108, n. 1-2, p. 89-99, 2015. DOI: 10.1400/240197

    Abstract: Snake venom is a myriad of biologically active proteins and peptides. Three finger toxins are highly conserved in their molecular structure, but interestingly possess diverse biological functions. During the course of evolution the introduction of subtle mutations in loop regions and slight variations in the three dimensional structure, has resulted in their functional versatility. Cytotoxin-1 (UniProt ID: P01467), isolated from Naja mossambica mossambica, showed the potential to inhibit chymotrypsin and the chymotryptic activity of the 20S proteasome. In the present work we describe a molecular model of cytotoxin- 1 in complex with chymotrypsin, prepared by the online server ClusPro. Analysis of the molecular model shows that Cytotoxin-1 (P01467) binds to chymotrypsin through its loop I located near the N-terminus. The concave side of loop I of the toxin fits well in the substrate binding pocket of the protease. We propose Phe10 as the dedicated P1 site of the ligand. Being a potent inhibitor of the 20S proteasome, cytotoxin-1 (P01467) can serve as a potential antitumor agent. Already snake venom cytotoxins have been investigated for their ability as an anticancer agent. The molecular model of cytotoxin-1 in complex with chymotrypsin provides important information towards understanding the complex formation.

    Icon

  • IPEN-DOC 27112

    HERNANDES, CAMILA; SILVA, BRUNA da; KLINGBEIL, MARIA de F.G. ; MATHOR, MONICA B. ; PEREIRA, ANA M.S.; SEVERINO, PATRICIA. Avoiding chemotherapy resistance in squamous cell carcinomas: anticancer activities of terpenoids and their impact on the regulation of microRNAs. Cancer Research, v. 77, 13 Supplement, 2017. DOI: 10.1158/1538-7445.AM2017-5456

    Abstract: MicroRNAs are small noncoding RNAs that play important roles in cellular biology. They have been implicated in pharmacogenomics by down-regulating genes that are essential for drug function. In this work we verified the potential anticancer activity of the quinone methide triterpenes maytenin and 22-β-hydroxymaytenin, as well as of a quinone methide triterpene-rich extract obtained from cultivated Maytenus ilicifolia root cells, and evaluated the associated microRNA expression following half maximal inhibitory concentration (IC50) treatment. Standard selectivity index (SI) for the isolated compounds and the root cell extract was determined by the logarithmic shift in effective concentration (IC50) between cancer cell lines and oral keratinocytes. Both isolated molecules as well as the root cell extract presented pronounced antiproliferative and pro-apoptotic activities in four cell lines derived from head and neck squamous cell carcinomas, including a metastasis-derived cell line. A positive SI, with an average 2-fold increase in potency, was detected for single agents and for the extract. MicroRNA expression profiles were assessed at 24h, 48h and 72h following treatment and an average of 100 molecules presented consistent marked variation in expression levels. Considering associations of microRNAs, genes they regulate, and the drugs effects dependent on these genes, the down-regulation of miR-193a-3p and miR-21 in treated cells is of particular interest. Both microRNAs have been involved in 5-fluorouracil and cisplatin resistance, current agents of standard chemoradiotherapy for locally advanced head and neck cancer. Squamous cell carcinoma of the head and neck is one of the most common cancer types worldwide whereas treatment options based on conventional therapies or targeted therapies under development have limited efficacy. Plant-derived products are valuable sources for the development of new therapeutic options for cancer treatment or as synergistic agents in existing regular care.

    Icon

  • IPEN-DOC 27111

    REIS, S.L. ; MUCCILLO, E.N.S. . Ionic conductivity of doped lanthanum gallate and strontium gallate composites. ECS Transactions, v. 80, n. 9, p. 141-149, 2017. DOI: 10.1149/08009.0141ecst

    Abstract: Polycrystalline ceramic solid electrolytes based on strontium- and magnesium-doped lanthanum gallate exhibit high ionic conductivity and find potential application in solid oxide fuel cells operating at intermediate temperatures. Sintering of this solid electrolyte is usually carried out at high temperatures, being responsible for loss of Ga and consequent formation of impurity phases. In this work, composites consisting of La0.9Sr0.1Ga0.8Mg0.2O3-δ with additions of strontium gallate were prepared by solid state reaction, and the influence of the additiveon electrical conductivity and phase composition of the composite electrolyte was investigated. The sintered density of composites is higher than 95% of the theoretical value after sintering at 1350°C. The contents of impurity phases decreased with increasing additions of strontium gallate. The overall ionic conductivity of the composites is higher than that of LSGM. This effect is attributed to the decrease in the fraction of free MgO at grain boundaries in the composites.

    Icon

View more

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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