Submissões recentes

  • IPEN-DOC 27164

    BENALCAZAR JALKH, E.B.; BERGAMO, E.T.P.; MONTEIRO, K.N.; CESAR, P.F.; GENOVA, L.A. ; LOPES, A.C.O.; LISBOA FILHO, P.N.; COELHO, P.G.; SANTOS, C.F.; BORTOLIN, F.; PIZA, M.M.T.; BONFANTE, E.A.. Aging resistance of an experimental zirconia-toughened alumina composite for large span dental prostheses: optical and mechanical characterization. Journal of the Mechanical Behavior of Biomedical Materials, v. 104, p. 1-9, 2020. DOI: 10.1016/j.jmbbm.2020.103659

    Abstract: Purpose: To synthesize a zirconia-toughened alumina (ZTA) composite with 85% alumina matrix reinforced by 15% zirconia and to characterize its optical and mechanical properties before and after artificial aging, to be compared with a conventional dental zirconia (3Y-TZP). Material and methods: After syntheses, ZTA and 3Y-TZP powders were uniaxially and isostatically pressed. Greenbody samples were sintered and polished to obtain 80 disc-shaped specimens per group (12 x 1 mm, ISO 6872:2015). The crystalline content and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Optical properties were determined by the calculation of contrast ratio (CR) and translucency parameter (TP) using reflectance data. Mechanical properties were assessed by Vickers hardness, fracture toughness and biaxial flexural strength test (BFS). All analyses were conducted before and after artificial aging (20h, 134 °C, 0.22 MPa). Optical parameters and microhardness differences were evaluated through repeated-measures analysis of variance (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results: The synthesis of the experimental ZTA composite was successful, with 98% of theoretical density, as shown in the SEM images. XRD patterns revealed typical zirconia and alumina crystalline phases. ZTA optical properties parameters showed no effect of aging, with a high CR and low TP values denoting a high maskingability. 3Y-TZP presented lower masking-ability and aging significantly affected its optical properties. ZTA Vickers hardness, fracture toughness and Weibull parameters, including characteristic stress and Weibull modulus were not influenced by aging, while 3Y-TZP presented a significant decrease in characteristic stress and increase in fracture toughness after aging. The ZTA probability of survival for missions of 300 and 500 MPa was estimated at ~99% validating its use for 3-unit posterior fixed dental prostheses (FDP), and no different from conventional 3Y-TZP. At high-stress mission (800 MPa) a significant decrease in probability of survival was observed for aged 3Y-TZP (84%) and for immediate and aged ZTA (73 and 82% respectively). Conclusion: The ZTA composite presented a dense microstructure, with preservation of the crystalline content, optical and mechanical properties after artificial aging, which encourages future research to validate its potential use for large span FDP.


  • IPEN-DOC 27163

    DIAZ, J.C.C.A. ; MUCCILLO, R. . Liquid-phase flash sintering 8YSZ with alkali halide sintering aids. Journal of the European Ceramic Society, v. 40, n. 12, p. 4299-4303, 2020. DOI: 10.1016/j.jeurceramsoc.2020.03.022

    Abstract: The properties of ZrO2: 8 mol% Y2O3 (8YSZ) ceramics with LiF and KCl sintering aids for liquid phase formation during electric field-assisted sintering were studied. Sintering experiments were carried out at 650 °C under 200 V cm−1 AC electric field by varying current density, current application time, as well as LiF and KCl contents. Pellets sintered with KCl addition had cavities, cracks and fractures. Pellets sintered with 15 wt.% LiF, on the other hand, were homogeneous after thermal removal of LiF upon Joule heating. Low electric current densities coupled with longer application times produced homogeneous specimens. Three different stages were identified during sintering experiments: (i) LiF melting with the electric field applied at furnace temperatures lower than its melting point, (ii) shrinkage due to liquid phase formation and LiF removal, (iii) final densification due to grain growth and pore elimination. The electrical behavior and an estimate of the porosity were carried out by electrochemical impedance spectroscopy measurements.


  • IPEN-DOC 27162

    MARCELLO, BIANCA A. ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Effect of growth parameters on the photocatalytic performance of TiO2 films prepared by MOCVD. Journal of the Brazilian Chemical Society, v. 31, n. 6, p. 1270-1283, 2020. DOI: 10.21577/0103-5053.20200012

    Abstract: The present study evaluated the main factors that influence the photocatalytic activity of titanium dioxide (TiO2) films grown by metalorganic chemical vapor deposition (MOCVD) at 400 and 500 °C, in different growth times. The photocatalytic behavior was analyzed by measuring the methyl orange dye degradation at different pH values. Structural and morphological characteristics, and the recyclability of the catalysts for several cycles were also investigated. Anatase phase was identified in all films. The higher photodegradation performances were obtained at acidic pH. The results demonstrated that the photocatalyst thickness is an important parameter in heterogenous photocatalysis. The best photocatalytic result occurred for the 395 nm-thick TiO2 film grown at 400 °C, which presented 65.3% of the dye degradation under UV light. The recyclability experiments demonstrated that the TiO2 films grown by MOCVD present a great stability after several photocatalytic cycles, which allows their practical application for water treatment with high efficiency.


  • IPEN-DOC 27161

    TUDELA, DIEGO R.G. ; ARAUJO, ASTOLFO G.M.; TATUMI, SONIA H.; MITTANI, JUAN C.R.; MUNITA, CASIMIRO S. . Preliminary evidence of prehistoric human activity by chemical analysis of sediments from Lapa Grande de Taquaraçu archaeological site using INAA. Journal of Radioanalytical and Nuclear Chemistry, v. 325, n. 3, p. 725-736, 2020. DOI: 10.1007/s10967-020-07217-2

    Abstract: This paper analyzes the mass fractions of Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn determined from sixty sediment samples obtained from the Lapa Grande de Taquaraçu archaeological site using instrumental neutron activation analysis, INAA. The archaeological site is located in the municipality of Jaboticatubas, about 60 km from Belo Horizonte, Minas Gerais State, Brazil. The dataset was explored by means of cluster analysis, principal component analysis and discriminant analysis. The study showed three different compositional groups related to anthropogenic sediment, fluvial system and oxisols, respectively. The crystalline structure of each group were studied using X-ray diffraction, XRD.


  • IPEN-DOC 27160

    ARAUJO, MARIANA S. ; SILVA, ANTONIO C. ; BARTOLOMÉ, JOSÉ F.; MELLO-CASTANHO, SONIA . Structural and thermal behavior of 45S5 Bioglass®-based compositions containing alumina and strontium. Journal of the American Ceramic Society, v. 103, n. 6, p. 3620-3630, 2020. DOI: 10.1111/jace.17061

    Abstract: The present research exposes the influence of 2 mol% of Al2O3 and 2 mol% SrO in 45S5 Bioglass®-based compositions. Four compositions were produced to elucidate the difference in how both oxides influence structure and thermal behavior separately and their synergy when together. Thermal properties, crystallization tendency, and sintering behavior was evaluated by differential scanning calorimetry, hot stage microscopy, and dilatometry. Changes of medium-range structures were characterized by Qn distribution of Raman spectroscopy and evaluation of 31P, 27Al, 23Na, and 29Si environment obtained by magic angle spinning nuclear magnetic resonance. Despite Qn distribution was predominantly Q2 in all samples, the composition criteria used enabled improved processing and stabilibity characteristics. The addition of Al2O3 and SrO promoted larger sinterability parameter (Sc) which indicates better sintering behavior, the glass stability against crystallization doubled (KH) compared to 45S5 and the processing window enlarged from 106 to 171.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.


  • 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.

    Palavras-Chave: crystallography; crystallization; crystals; materials working; rheology; programming languages; engineering; educational tools; knowledge management; knowledge preservation


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • 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


  • IPEN-DOC 27115


    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


  • 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


  • 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.


  • 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.


  • 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.


  • IPEN-DOC 27110

    MONTEIRO, WALDEMAR A. (Ed.) . Light Metal Alloys Applications. Rijeka, Croatia: Intech, 2014. 242 p. DOI: 10.5772/57069


  • IPEN-DOC 27109

    MONTEIRO, WALDEMAR A. (Ed.) . New Features on Magnesium Alloys. Rijeka, Croatia: Intech, 2012. 174 p. DOI: 10.5772/2810


  • IPEN-DOC 27108

    MONTEIRO, W.A. ; BUSO, S.J.; SILVA, L.V. da . Application of magnesium alloys in transport. In: MONTEIRO, WALDEMAR A. (Ed.). New Features on Magnesium Alloys. London, UK: IntechOpen, 2012. p. 1-14, cap. 7. DOI: 10.5772/48273


  • IPEN-DOC 27107

    PEREIRA, VIVIAM S.M.; ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V. . Efeito de tratamentos de envelhecimento sobre a resistência à corrosão da liga de magnésio AZ91D / Ageing heat treatments effect on the corrosion resistance of the AZ91D magnesium alloy. In: CONGRESSO INTERNACIONAL ANUAL DA ABM, 67th, July 31 - August 7, 2012, Rio de Janeiro, RJ. Proceedings... 2012. p. 192-202.

    Abstract: O efeito de tratamentos térmicos de envelhecimento (T6) sobre a resistência à corrosão da liga de magnésio AZ91D foi estudado. Amostras solubilizadas a 445°C por 24 h foram envelhecidas a 200 °C por tempos de 8 h, 16 h e 24 h. Todos os tratamentos foram realizados em forno mufla, sob atmosfera inerte (argônio), seguidos de resfriamento em água. Para observação das alterações microestruturais, utilizaram-se as técnicas de microscopia óptica e de MEV. O comportamento eletroquímico foi avaliado por ensaios de espectroscopia de impedância eletroquímica e de polarização potenciodinâmica, utilizando-se solução de Hanks, a 37 °C como eletrólito. O período de imersão foi de 7 dias. Com o tratamento de solubilização, ocorreu a dissolução do constituinte eutético, restando somente a matriz (fase α-Mg) saturada com alumínio, juntamente de resquícios de β- Mg17Al12. Com o tratamento de envelhecimento foram observados precipitados ricos em alumínio (β-Mg17Al12) sobre a matriz. A amostra envelhecida por 8 h foi a que mostrou menor valor de resistência à corrosão; as amostras tratadas por 16 h e 24 h apresentaram valores de impedância semelhantes, sendo que a amostra envelhecida por 16 h apresentou o melhor desempenho.


  • IPEN-DOC 27106

    RODRIGUES, ANTONIO C.I. ; MADI FILHO, TUFIC ; SILVA, DAVILSON G. da . Analysis and construction of the high density storage racks for spent fuel of the research reactor IEA-R1. RAD Conference Proceedings, v. 3, p. 123-126, 2018. DOI: 10.21175/RadProc.2018.27

    Abstract: The IEA-R1 research reactor works 40h weekly, with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions, the reactor operating for 32h/week will have 3 spent fuel by year, approximately 3 utilization rate Positions/year; thus, we will have only about six years of capacity for storage. Since the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel by doubling the wet storage in the reactor’s pool. 3M’s neutron absorber BoralcanTM was chosen after reviewing the literature about available materials for the construction of a new storage rack. This work presents studies for the construction of new storage racks with double of capacity using the same place of the current ones. Criticality safety analysis was performed with MCNP-5 Monte Carlo code, using two Evaluated Nuclear Data Files (ENDF/B-VI and ENDF/B-VII) in calculations, and subsequently, the results were compared. The full charge of the storage rack with only new fuel elements (maximum reactivity) was considered to calculate the keff. The results obtained in the simulations show that it is possible doubling the storage capacity of the spent fuel elements. Additionally, it complies with safety limits established by International Atomic Energy Agency (IAEA) and Brazilian Commission of Nuclear Energy (CNEN) standards to the criticality criteria (keff <0.95). This is only possible with the use of neutron absorber material.

    Palavras-Chave: research reactors; spent fuel storage; fuel racks; monte carlo method; boron; iear-1 reactor; fuel storage pools; fuel elements; storage


  • IPEN-DOC 27105

    OTON, LAIS F.; OLIVEIRA, ALCINEIA C.; ARAUJO, JESUINA C.S. de; ARAUJO, RINALDO S.; SOUSA, FRANCISCO F. de; SARAIVA, GILBERTO D.; LANG, ROSSANO; OTUBO, LARISSA; DUARTE, GIAN C. da S.; CAMPOS, ADRIANA. Selective catalytic reduction of NOx by CO (CO-SCR) over metal-supported nanoparticles dispersed on porous alumina. Advanced Powder Technology, v. 31, n. 1, p. 464-476, 2020. DOI: 10.1016/j.apt.2019.11.003

    Abstract: The selective catalytic reduction of NOx by CO (CO-SCR) was investigated over metals supported on porous alumina. The Pt, Co, Fe and Ni nanoparticles were dispersed on the alumina and characterized by XRD, textural properties, FTIR spectroscopy, chemical analyses, Py adsorption followed by FTIR measurements, HRTEM and SEM-EDS. Among the solids studied, the Pt/Al2O3 and NiPt/Al2O3 catalysts exhibited improved performance due to the interaction and synergy between the Pt(Ni) nanoparticles and the support. In other words, the electron transfer facility between the PtOx(Ni) and chlorined Pt species on the support provided a more active solid in the CO-SCR reaction. The surface acidity of Lewis acid sites and the porous features of the Pt/Al2O3 and NiPt/Al2O3 catalysts also contributed significantly to the high performance of these materials in the NOx conversion. The Pt/Al2O3 and NiPt/Al2O3 catalysts were tolerant to the poisoning by SO2 and H2O and depicted a superior catalytic performance, compared to the other solids.

    Palavras-Chave: nanoparticles; catalysts; aluminium oxides; x-ray diffraction; porous materials; synthesis; selective catalytic reduction; nitrogen


  • IPEN-DOC 26678

    CABRAL, FERNANDA V. ; SABINO, CAETANO P.; DIMMER, JESICA A.; SAUTER, ISMAEL P. ; CORTEZ, MAURO J.; RIBEIRO, MARTHA S. . Preclinical investigation of methylene blue-mediated antimicrobial photodynamic therapy on Leishmania parasites using real-time bioluminescence. Photochemistry and Photobiology, v. 96, n. 3, p. 604-610, 2020. DOI: 10.1111/php.13188

    Abstract: Cutaneous leishmaniasis (CL) is a neglected disease that promotes destructive lesions. Difficulties in treatment are related to accessibility of drugs, resistance and toxicity. Antimicrobial photodynamic therapy (APDT) has been emerging as a promising treatment for CL. In this work, we evaluated methylene blue (MB)-mediated APDT (MB-APDT) on Leishmania amazonensis in vitro and in vivo by bioluminescence technique. In vitro, MB-APDT was performed using a red LED (k = 660 11 nm, 100 mW cm 2) and MB (100 μM) at different light doses. In vivo, mice were infected and 4 weeks later, randomly divided into three groups: control, APDT 1 (single session) and APDT 2 (two sessions of MB-APDT). MB was used at 100 μM and energy dose was established at 150 J cm 2. Parasite burden, lesion size and pain were evaluated weekly for 4 weeks. In vitro, lethal dose for 90% parasite inactivation was achieved at 48.8 J cm 2. In vivo, although APDT 1 and APDT 2 groups have showed similar parasite burden after 4 weeks, two sessions were clinically better, especially considering the inflammatory process associated to CL. Our findings reinforce MB-APDT as a costeffective treatment to combat CL.

    Palavras-Chave: antimicrobial agents; therapy; photosensitivity; methylene blue; parasites; bioluminescence; photochemistry; in vivo; in vitro; mice


  • IPEN-DOC 26454

    LOBO, ALEXANDRE R.; GAIEVSKI, EDUARDO H.S.; MESQUITA, CARLOS H. de ; DE CARLI, EDUARDO; TEIXEIRA, PRYSCILA D.S.; PEREIRA, ROSA M.R.; BORELLI, PRIMAVERA; SÁ, LILIAN R.M. de; COLLI, CELIA. Increased adiposity by feeding growing rats a high-fat diet results in iron decompartmentalisation. British Journal of Nutrition, v. 123, n. 10, p. 1094-1108, 2020. DOI: 10.1017/S0007114519002320

    Abstract: The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue ‘i’ to tissue ‘j’) adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ki;j ¼ a ×Mb. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.

    Palavras-Chave: fats; adipose tissue; compartments; diet; iron; chemical composition; immunoglobulins; nutrition


  • IPEN-DOC 25779

    AZEVEDO, JULIANA de S.; QUINTINO, MARILIA T.A.; ROGERO, SIZUE O. ; ZAMPIERI, MARIA C.T. ; ROGERO, JOSE R. . Histopathological changes in zebrafish exposed to sublethal concentrations of 89nm silver nanoparticles for application in environmental diagnostics. Human and Ecological Risk Assessment, v. 26, n. 5, p. 1207-1220, 2020. DOI: 10.1080/10807039.2018.1560219

    Abstract: The use of biomarkers as indicators of environmental contamination has been shown to be an excellent indicator of changes in biota. Histopathological lesions are commonly used in biomonitoring studies as they provide information regarding both acute and chronic exposure. The use of nanoparticle materials has been widespread in recent years. However, not much is known about their ecological effects on the natural environment. Thus, the aim of this study was to assess the sublethal effects of silver nanoparticles (AgNP) with mean diameters of 89nm in the zebrafish Danio rerio by the determination of the LC50; 48 h and histopathological assays in gills. The obtained LC50; 48 h was 8.18 mgL 1. The histopathological gill assessment showed primary responses indicative of acute damage as aneurysms (32.76%), hyperplasia (20.69%) and partial (30.17%) and total lamellar fusion (6.9%) of secondary lamellae. No deposition of AgNP was observed in any tested sample gills, suggesting other organs target to absorption and detoxification. In fact, the AgNP causes sublethal damage in the gills of zebrafish but is not able to accumulate in this tissue. Finally, the data shown in this study contribute to the construction of a database on the AgNP exposure in aquatic organisms.

    Palavras-Chave: biological markers; environment; monitoring; environmental quality; gills; fishes; environmental effects; water pollution; bioassay; toxic materials; histology; pathology; risk assessment


  • IPEN-DOC 25761

    BOIDI, G.; TERTULIANO, I.S.; PROFITO, F.J.; ROSSI, W. de ; MACHADO, I.F.. Effect of laser surface texturing on friction behaviour in elastohydrodynamically lubricated point contacts under different sliding-rolling conditions. Tribology International, v. 149, p. 1-9, 2020. DOI: 10.1016/j.triboint.2019.02.021

    Abstract: The Laser Surface Texturing (LST) technique has been largely investigated to improve the tribological performance of lubricated contacts. The present contribution is aimed at scrutinizing the influence of three texture configurations fabricated by LST on the tribological performance of elastohydrodynamic (EHD) point contacts under different slide-to-roll ratios (SRR), entrainment velocities and inlet temperatures. Friction experiments were conducted through a series of ball-on-disk tests in the MTM-2 (Mini-Traction Machine) tribometer. Main results showed that the texture configurations promoted significant effects under boundary and mixed lubrication conditions, and also affected the full-film EHD regime at higher temperatures. Furthermore, the tribological performance of textured samples was strongly related to the texture depth. Shallower texture designs (∼0.5 μm) reduced friction compared to untextured material, whereas deeper features (> 1 μm) generally led to detrimental results. In general, dimples configuration decreased the lift-off speed and promoted full-film EHD conditions for a larger range of speeds, whereas radial curved grooves yielded to friction reduction under mixed lubrication conditions, moving the transition from boundary to mixed regimes to lower speeds, especially for intermediate lubricant viscosity.

    Palavras-Chave: lasers; surfaces; texture; hydrodynamics; elasticity; tribology; surface properties; wear


  • IPEN-DOC 27104

    SANTOS, G.A. dos; FIGUEIREDO, W.; SCHMITT, Y.P.; NASCIMENTO, M.S.; MIRANDA, F.; BATALHA, G.F.; COUTO, A.A. . Study on closed-die forging in stainless steel as standard ASTM F138 in grain size function. In: ÖCHSNER, ANDREAS (Ed.); ALTENBACH, HOLM (Ed.). Engineering Design Applications II: Structures, Materials and Processes. Cham, Switzerland: Springer Nature Switzerland, 2020. p. 133-153, (Advanced Structured Materials, 113). DOI: 10.1007/978-3-030-20801-1_10

    Abstract: Forging is a bulk deformation process in metal working commonly employed in the manufacture of metallic materials prostheses. Depending on the compressive loads applied to the material, structures (grain sizes) are formed which increase its strength. By forging an ASTM F138 stainless steel, the heating of material in a suitable temperature is of fundamental importance to be formed without the presence of folds arising from the process and as a result we can obtain a proper microstructure. This work aims to define the accurate temperature in relation to the strain rate applied in the hot die forging process. Besides, it is used a closed-die forging in which cavity has different thickness that stimulates the profile of an orthopedic plate. Four ranges of temperature used in the process vary between 1000 and 1200 °C, with a strain rate ranging from 400 to 600 s−1.Results demonstrate that there is a transitional temperature close to 1050 °C, where temperatures of 1000–1040 °C provide satisfactory grain size and temperatures of 1100 and 1200 °C, showed limitations in grain size, greater than those recommended by ASTM F 621.


  • IPEN-DOC 27103

    MACHADO, ALESSANDRA C.F.E. (Ed.); HONÓRIO, DANIEL H. (Ed.); PEREIRA, DÉBORA A. (Ed.); LIMA, ADRIANA T. de (Ed.); AQUINO, AFONSO R. de (Ed.); CORDOVIL, CLEBER de S. (Ed.); NICOLETTI, HENRIQUE P. (Ed.); SANTOS, JOSÉ R. (Ed.); SILVA, KARINA M. da (Ed.); MAIA, LUIZ C. (Ed.); POPST, LUIZ A.A. (Ed.); SANTOS, MARIA L.D.P. (Ed.); SANTOS, MARIANA (Ed.); WILLMERSDORF, OFÉLIA de F.G. (Ed.); DIAS, PAULO E.V. (Ed.); SARACURA, VALÉRIA F. (Ed.); COIMBRA, VINÍCIUS P. (Ed.) . I Workshop sobre Educação Ambiental: Resultados e Encaminhamentos. Brasília, DF; Araçoiaba da Serra, SP: ICMBio; FLONA de Ipanema, 2018. 112 p.


  • IPEN-DOC 27102

    INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES (Ed.); SAKATA, SOLANGE K. (Coord.); RODRIGUES, DEBORA F. (Coord.); OYANEDEL-CRAVER, VINKA (Coord.) . Conference Proceedings of 1st Pan American Congress of Nanotechnology: Fundamentals and Applications to Shape the Future - PanNano 2017. São Paulo, SP, 2018. 257 p.


  • IPEN-DOC 27101

    MIZUTANI, GUSTAVO ; VEGA, OSCAR . Análise de agrotóxicos em alimentos vegetais com alto teor de proteínas via cromatografia acoplada a espectrometria de massas tandem. In: CONGRESSO ANALITICA, 6th.; CONGRESSO ANALITICA LATIN AMERICA, 15th.; NANO TRADE SHOW; CIRCUITO DO CONHECIMENTO E INOVAÇÃO, September 24-26, 2019, São Paulo, SP. Poster... 2019.


  • IPEN-DOC 27100

    CARVALHO, ELIAS F. ; OSTERMANN, CAROLINE K. ; BUSTILLOS, JOSE O.V. . Vertical profile analysis of wind flow to obtain optimal eddy covariance parameters. In: ATTO WORKSHOP, 3rd, September 16-20, 2019, Manaus, AM. Poster... 2019.


  • IPEN-DOC 27099



  • IPEN-DOC 27098


    Abstract: O presente trabalho apresenta um método simples e rápido para a determinação por injeção direta de 68 ingredientes ativos (i.a.) de agrotóxicos em água para consumo humano, empregando cromatografia líquida acoplada ao espectrômetro de massas de alta resolução (LC-HRMS/Orbitrap). A técnica por injeção direta dispensa o tratamento prévio ou concentração da amostra, reduz o consumo de solventes e elimina possíveis perdas de analitos. O analisador de massas Orbitrap possui resolução e sensibilidade elevadas, alta especificidade na identificação de compostos por meio da massa exata e permite a determinação simultânea de resíduos de agrotóxicos de diferentes classes e propriedades físico-químicas. Para a identificação e quantificação dos i.a. foi utilizado cromatógrafo a líquido de ultraperformance (UHPLC) Ultimate 3000 Dionex acoplado ao analisador de massas Exactive Plus Orbitrap™ Thermo Scientific, coluna analítica Hypersil Gold C18 aQ Thermo Scientific, fonte de ionização por electrospray com aquecimento (HESI) e aquisição dos dados nos modos positivo e negativo. O erro aceitável de exatidão de massas foi de até 5ppm. O método foi realizado em Full MS e All Ion Fragmentation (AIF), numa faixa de massas entre 60 e 900m/z com resolução de aquisição de 35000 e 17500, respectivamente, tempo de análise de 12minutos. Para as análises, à amostra de água foram adicionados ácido fórmico 0,1% (v/v) e metanol 0,5% (v/v). A validação do método multirresíduo foi realizada por ensaios de recuperação, avaliando exatidão, precisão, linearidade, limites de detecção (LD) e de quantificação (LQ). A avaliação de desempenho e critérios de aceitação foram baseados nos descritos da SANTE 11813/2017. As curvas analíticas para todos os compostos foram obtidas em triplicata, na faixa de concentração de 0,2 a 50 μg.L-1, com exceção dos i.a. atrazina e simazina, cuja faixa de trabalho foi de 0,06 a 16 μg.L-1. Os limites de detecção e de quantificação foram estabelecidos por estudos estatísticos e variaram de 0,19 a 2,12 μg.L-1, e de 0,56 a 6,53 μg.L-1, respectivamente. Os valores de LQ obtidos dos ativos constantes na Portaria de Consolidação MS-GM nº 05/2017 (Brasil, 2017) analisados neste trabalho estão abaixo dos limites máximos estabelecidos. Sob condições de repetibilidade (N=5), as médias das recuperações dos i.a. nos níveis de fortificação 0,5; 1; 2; 5 e 40μg.L-1, e para a atrazina e simazina em 0,16; 0,32; 0,64; 1,6 e 12,8μg.L-1, variaram de 75,07% a 123,06% e DPR de 0,74 a 23,02%. As amostras em branco não apresentaram interferentes dos compostos estudados (efeito matriz). O método multirresíduo para análise de 68 i.a. de agrotóxicos por injeção direta em LCHRMS mostrou-se eficiente, simples, rápido, sensível e confiável para a análise de amostras de água. A implantação da metodologia terá aplicações relevantes para a área de Saúde Pública e permitirá o desenvolvimento de novas pesquisas referentes à contaminação de água para consumo humano. Os resultados obtidos poderão subsidiar as ações de vigilância sanitária, bem como proporcionar dados que contribuam e incentivem a revisão das legislações vigentes.


  • IPEN-DOC 27097

    FERREIRA, WANDERSON L. ; PEREIRA, LUCIANO F.D. ; COSTA, MESSIAS de S.; SCALISE, LEVY ; GONÇALVES, VITOR C. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Investigation on the role of oxygen vacancies in the Cd hyperfine properties in (Co, Mn)-doped CeO2. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 86-86.

    Abstract: Ceria is known to have intrinsic oxygen vacancies that affect specific properties for semiconductor applications. Recently, incorporation of impurities to ceria for vacancy formation control as well as the role of dopants in the physical and chemical ceria properties have gained much attention, especially when doped with transition metals. Local disorder originated from oxygen vacancies and doping is the aim of several studies in which hyperfine interactions techniques have showed a great tool to investigate it. In particular, perturbed angular correlation spectroscopy (PAC) measurements with 111Cd for pure and TM (Co, Mn)-doped CeO2 have exhibited a range of quadrupole frequencies [1, 2]. In order to elucidate the several electric field gradients (efg) in these systems, we have carried out band structure calculations by means of density functional theory (DFT) in the ceria doped with Cd and TM (Co, Mn) to study the local disorder from the hyperfine interactions point of view. We performed spin-polarized calculation using the full-potential augmented plane-waves plus local-orbitals (FP-LAPW) method and Perdew–Burke–Ernzerhof generalized gradient approximation embodied into WIEN2k code [3]. We simulated several charge states in pure and TM-doped CeO2 supercells with oxygen vacancies focusing on electronic distribution in the vicinity of Cd. Our efg results showed a good agreement with 111Cd quadrupole frequency range obtained from PAC experiments. Thus, we improved the understanding about the role of Cd and TM in the ceria oxygen vacancy formation.


  • IPEN-DOC 27096

    BURIMOVA, A. ; CARBONARI, A.W. ; RICHARD, D.; PEREIRA, L.F.D. ; GENEZINI, F.A. . Mechanisms of reduction in V2O5 and MoO3 studied by PAC spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 59-59.

    Abstract: Structural evolution of vanadium (V) and molybdenum (VI) oxides with temperature was studied by Time Differential Perturbed Angular Correlation (TDPAC) spectroscopy in different atmospheres with 111Cd probe incorporated by wet impregnation. In case of V2O5 sealed in vacuum, the critical temperature for probe diffusion was found to be above 500oC, whereas for MoO3 this barrier was 600oC. The diffusion was suppressed in low pressure oxygen atmosphere. The behavior of hyperfine parameters on heating to melting point of V and Mo oxides and subsequent cooling to room temperature was analyzed. TDPAC results were complemented by X-ray diffraction data. We discuss comproportionation, topotactic, competitive and consecutive mechanisms as the candidates to describe V2O5 → VO2 and MoO3 → MoO2 reduction.


  • IPEN-DOC 27095

    DARRIBA, G.N.; RICHARD, D.; MUÑOZ, E.L.; RUNCO, J.; CARBONARI, A.W. ; PETRILLI, H.M.; RENTERIA, M.. Dynamic hyperfine interactions in (111In→)111Cd-doped SnO2 and SnO semiconductors: ab initio approach to the electron-capture after-effects phenomenon. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 103-103.

    Abstract: In the PAC literature, the so-called “after-effects” phenomenon refers to the electronic relaxations processes of a probe-atom following the electron-capture (EC) nuclear-decay of its radioactive parent. This effect has been observed in PAC experiments on semiconducting and insulating oxides doped with 111In(→111Cd), through the existence of dynamic hyperfine interactions (i.e., with time-dependent anisotropies), dependent and reversible with measuring temperature. We present here results of PAC experiments in (111In →)111Cd-doped SnO2 and SnO that have been successfully analyzed with a time-dependent on-off model for the perturbation factor. These results showed combined dynamic plus static hyperfine interactions whose electric-field gradients (EFG) were associated to different stable electronic configurations close to the 111Cd nucleus. The dynamic regime is originated in fast fluctuations between these different electronic configurations. Density functional theory-based electronic-structure calculations of Cd-doped SnO2 and SnO were performed as a function of the charge state of the impurity. In SnO2, the impurity introduces a double acceptor level in the top of the valence band together with isotropic outward relaxations of the nearest oxygen neighbors. The variation of the calculated EFG tensor as a function of the charge state of the Cd impurity level shows an interesting behavior that explains the experimental results, giving strong support from first principles to the electron-capture after-effects proposed scenario. A similar ab initio analysis in Cd-doped SnO, in which Cd is nominally an isovalent impurity, also gave account succesfully of the experimental results. The EC decay of 111In to 111Cd and the electric nature of the host are shown to contribute to the existence of these types of time-dependent hyperfine interactions, showing that the acceptor character of the impurity seems not to be a necessary condition to produce after effects at least in Sn oxides.


  • IPEN-DOC 27094

    SANTOS, R.A. ; SANTOS, B.B. ; CORREA, E.L. ; PEREIRA, L.F.D. ; SCHELL, J.; CORREIA, J.G.M.; LUPASCU, D.C.; SCHAAF, P.; HOFSAESS, H.C.; SAXENA, R.N. ; CARBONARI, A.W. . Hyperfine interactions measurements in bismuth tri-iodide (BiI3) by time differential perturbed angular correlation spectroscopy (TDPAC). In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 101-101.

    Abstract: Bismuth tri-iodide (BiI3) is a material of great interest in applications such as solar cells and semiconductor detectors. In the work reported here, bulk samples of BiI3 were characterized by time differential perturbed angular correlation spectroscopy (TDPAC) at different temperatures using 111mCd (111Cd) and 111In (111Cd) as radioactive probes, inserted by implantation at ISOLDE/CERN and by thermal diffusion at IPEN, respectively. TDPAC measurements were used to investigate the hyperfine interactions at Bi sites in the crystalline structure of BiI3. The hyperfine parameters obtained were analyzed to elucidate the electrical properties expected for the mentioned technological applications. The optimal temperatures for annealing after the implantation (300°C and 320°C) were determined, allowing to observe the perturbation pattern R(t). Measurements show that the incidence of UV light at 350–363nm wavelength has an effect on the electronic structure around the Cd probe nuclei located near the surface of samples.


  • IPEN-DOC 27093

    PEREIRA, LUCIANO F.D. ; MESTNIK-FILHO, JOSE ; CABRERA-PASCA, GABRIEL A. ; BOSCH-SANTOS, BRIANNA ; FERREIRA, WANDERSON L. ; GONÇALVES, VITOR C. ; SCALISE, LEVY ; GENEZINI, FREDERICO A. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Insights into anomalous magnetic hyperfine field at Ce impurity in LaMn2X2 (X=Si, Ge): a study from first principles calculations. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 88-88.

    Abstract: The LaMn2X2 (X=Si, Ge) intermetallic compounds doped with cerium exhibit the interesting physical effects that are typical of the REMn2X2 (RE=rare earth) series (such as magnetocaloric, superconductivy) or are originated from cerium in specific electronic environment (e.g. Kondo, intermediate valence, strongly correlated electron). Recently, the magnetic hyperfine field (mhf) at 140Ce-doped LaMn2(Si(1-x)Gex)2 was determined by perturbed gamma-gamma angular correlation spectroscopy. The 140Ce mhf follow the host magnetization in LaMn2Si2, while in LaMn2(Si(1-x)Gex)2 (with x = 0.2 up to 1), it has anomalous behaviour, which was associated with 4f cerium mhf contribution. In this work, first principles band structure simulations were used to improve the understanding of the distance role (generated by interchange of Si and Ge) on mhf cerium contribution.


  • IPEN-DOC 27092

    PEREIRA, LUCIANO F.D. ; FERREIRA, WANDERSON L. ; GONÇALVES, VITOR C. ; SCALISE, LEVY ; GENEZINI, FREDERICO A. ; CORREA, EDUARDO L. ; SAXENA, RAJENDRA N. ; CARBONARI, ARTUR W. . Hyperfine interactions in Gd2Ti2O7 pyrochlore: ab initio calculations. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 87-87.

    Abstract: The cubic pyrochlore structure of the RE2Ti2O7 (R= rare earth) form is highly geometrically frustrated antiferromagnets and Gd2Ti2O7 is particularly interesting due to the fact gadolinium has a large magnetic moment and its orbital momentum is zero. Up to nowadays, a few investigations of the local structure on Gd2Ti2O7 using hyperfine interactions techniques were made. Namely, the magnetic hyperfine interaction at Gd previously reported from Mossbauer effect spectroscopy with 155Gd [1] and perturbed angular correlation (PAC) have used to reach electric field gradient at 111mCd and 111In probe nuclei [2]. However, these studies are lacking in interpretation, so first principles calculations may led to the elucidation of the electronic structure at the specific crystalline site. Then, Gd2Ti2O7 single and doped-Cd cell simulations have performed with full potential linearized augmented plane waves methods and generalized gradient approximation from Perdew-Burke-Ernzerhorf within the WIEN2k code. Electric field gradient and magnetic hyperfine components were evaluated.


  • IPEN-DOC 27091

    SALES, T.S.N. ; SAXENA, R.N. ; CARBONARI, A.W. . Study of the hyperfine parameters in Si and Fe doped HfO2 nanoparticles by perturbed angular correlation spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 83-83.

    Abstract: Nanoparticles (NPs) have attracted a great deal of interest due to their desirable properties suited for technological and medical applications. Hafnium dioxide (HfO2) can be used in both areas. HfO2 NPs were synthesized through sol-gel method, which allows an efficient and controlled doping of HfO2. In this work, we have investigated the effect of (5% at.) doping of HfO2 NPs with Si and Fe by measuring hyperfine interactions at 181Ta probe nuclei on Hf sites using the perturbed γ–γ angular correlations (PAC) spectroscopy. The structural and morphological analysis was carried out by X-ray diffraction (XRD) and transmission microscopy (TEM) techniques. For both samples, XRD results showed a single phase with the expected monoclinic structure and TEM results indicated NPs with an average diameter of approximately 30 nm. The hyperfine parameters were measured in the temperature range of 200-900 ºC. The radioactive 181Hf was produced by irradiating the samples with neutrons in the IEA-R1 reactor at IPEN. The samples were enclosed in the alumina tube instead of usual silica tube to avoid the formation of hafnon. Results of both samples showed that probe nuclei occupy three sites with different electric quadrupolar interactions. The major fractions (~65%), in both cases however, showed the well-known monoclinic structure of pure HfO2 [1]. The characterization of one of the minor fractions in Si doped HfO2 showing a tetragonal structure between 400-600 ºC is discussed.


  • IPEN-DOC 27090

    CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; CARVALHO JUNIOR, R.N.; SAXENA, R.N. ; CARBONARI, A.W. . Hyperfine interaction study of iron oxide nanoparticles coated with Amazon ucuúba, bacaba and açaí, oils by PAC spectroscopy using 111In-111Cd nuclear probe nuclei. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 82-82.

    Abstract: The use of nanoparticles coated with different materials have been the subject of study by many researchers to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work we used ucuúba (virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) oils to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native tree of the Amazon forest, whose oils are rich in fatty acids present in different proportions, such as, lauric, myristic, steatic, oleic, palmitic, and linoleic acid. These pure oils, free of solvents, were obtained by the extraction method with carbon dioxide in the supercritical state [2], and added during the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The samples were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Perturbed Angular Correlation (PAC) spectroscopy. The XRD results confirmed the formation of Fe3O4 phase. The TEM results determined the average size to be (> 5 nm) and possible spherical morphology of the magnetite nanoparticles. In order to perform the PAC measurements, 111In-111Cd probe nuclei were diffused in the powder samples at 973 K for 2.5 h. PAC measurements permitted the determination of electric quadrupole and magnetic dipole -hyperfine parameters as a function of temperature. The Curie temperature in each case was determined to be ~ 855 K.


  • IPEN-DOC 27089

    PAES, S.C.; CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; SAXENA, R.N. ; CARBONARI, A.W. . Effects of surfactant on the morphology of α-Bi2O3 synthesized by the Sol-gel method: hyperfine interaction study by PAC spectroscopy using 111In-111Cd nuclear probe nuclei. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 81-81.

    Abstract: Nano and micromaterial research, with a well-defined size and shape, has attracted attention from researchers in the areas of chemistry, physics, engineering and biomedicine, due to the wide range of possible applications such as: health, environment, catalysis and miniaturization of electronic devices. In this sense, the chemical routes of synthesis, such as Sol-Gel, are more prominent because it allows the production of particulate materials and thin films, with controllable size and morphology. In this work, bismuth oxide microparticles were synthesized by the Sol-Gel method using metallic bismuth (99.999% purity) in acid solution. Initially, bismuth was diluted with nitric acid solution and distilled water. After dilution, citric acid (600 mg) and ethylene glycol were added. The volume of ethylene glycol was varied from 1 to 3.75 mL, in order to study the morphological effects of its concentration. The samples were then subjected to the calcination process at 673 K for 12 hours. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS) and Raman spectroscopy. The XRD diffractograms and the Raman spectrum vibration bands showed that the synthesized samples correspond to the bismuth oxide in the alpha phase (α-Bi2O3) [1-3]. The EDS results show typical elements of bismuth oxide, without contaminants. The SEM images revealed different morphologies, ranging from the formation of flakes to microspherical particles with good size distribution (diameter 0.7 and 2.0 μm). All samples have a crystalline structure and vibration modes corresponding to the α-Bi2O3 phase, but these have totally different morphologies, which proves the dependence of the morphology with the concentration of ethylene glycol. In order to perform the PAC measurements, 111In-111Cd probe nuclei were diffused in the samples during synthesis. PAC measurements permitted the determination of electric quadrupole - hyperfine parameters as a function of temperature, from 50 to 673 K.


  • IPEN-DOC 27088

    CORREA, B.S.; COSTA, M.S. ; SENA, C. ; CABRERA-PASCA, G.A. ; CARVALHO JUNIOR, R.N.; SAXENA, R.N. ; CARBONARI, A.W. . Study by perturbed angular correlation spectroscopy with 111In-111Cd of iron oxide nanoparticles synthesized using Amazon ucuúba, bacaba and açaí, oils. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 80-80.

    Abstract: The use of nanoparticles coated with different materials are also a subject of study by many scientists to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work was used ucuúba (virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) oils to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native tree of the Amazon forest, whose oils is rich in fatty acids present in different proportions, such as, lauric, myristic, steatic, oleic, palmitic, and linoleic acid. These pure oils, free of solvents, was obtained by the extraction method with carbon dioxide in the supercritical state [2], and added to the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The samples were characterized by X-ray diffraction (XRD), it was possible to verify the formation of Fe3O4 nanoparticles by the position and width of the intensity peaks. Transmission electron microscopy (TEM) were used to observe the average size (> 5 nm) and possible spherical morphology of the magnetite nanoparticles. In order to perform perturbed angular correlation spectroscopy (PAC) the powder samples were heated at 973 K for 2,5 h to diffuse the 111In-111Cd probe nuclei. Using this technique, it is possible determine the electric quadrupole and magnetic dipole hyperfine parameters of the samples as a function of temperature, and it was determined the Curie temperature of ~ 855 K for both samples. The results showed that it is possible synthesized Fe3O4 nanoparticles using ucuúba, bacaba and açaí oils.


  • IPEN-DOC 27087

    KRYLOV, V.I.; BOSCH-SANTOS, B. ; CABRERA-PASCA, G.A. ; CARBONARI, A.W. ; SAXENA, R.N. ; LEITE NETO, O.F.S. . Magnetic hyperfine field at 119Sn and 111Cd probes in Gd5Ge4 studied by Mössbauer and PAC spectroscopy. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 39-39.

    Abstract: The magnetic structure of Gd5Ge4 belonging to the family of giant magnetocaloric Gd5(Si1-xGex)4 alloys [1] has been examined by magnetization measurements in single crystal [2, 3], X-ray resonant magnetic scattering (XRMS) [4], and neutron powder diffraction (NPD [5]. Gd5Ge4 crystallizes in the orthorhombic structure (space group Pnma) having three non-equivalent Ge-sites. At low temperatures, the Gd magnetic moments are ferromagnetically (FM) aligned within the slabs along the c-direction, while their stacking in the b-direction is antiferromagnetic (AFM) below 127 K [2, 4]. In this work, the temperature dependence of the magnetic hyperfine field (HF) and electric quadrupole interaction on 119Sn and 111Cd probe nuclei in Gd5Ge4 compound have been investigated by Mössbauer and perturbed angular correlation (PAC) spectroscopy. At the saturation, the HF magnitudes reach of Bhf =28.0(5) T and Bhf= 12.6(5) T for 119Sn and 111Cd, respectively, which correspond to the FM local magnetic environment for these probes. It was found that 119Sn probes are placed in two Ge positions, whereas 111Cd probes are located in only one of the three Ge positions in Gd5Ge4. Temperature dependence of Bhf for both 119Sn and 111Cd probes in Gd5Ge4 present anomalous behavior. In the range from 20 K to 120K, the HF decreases almost linearly when temperature increases. These anomalous behavior of Bhf(T) for 119Sn and 111Cd probes are in agreement with the temperature variation of the magnetic (070) and (010) peak intensities that have been found in XRMS [3] and NPD [4] studies. The AFM ordering temperature of Gd5Ge4, TN=129(1) K, found from the Bhf (T) is in agreement with previous results of [2 - 5]. Changes of the values and sign of the quadrupole shift of Mössbauer spectra for 119Sn atoms with the increase of temperature from 30 to 50 K confirm the spin-flop transition in Gd5Ge4 [2, 4].


  • IPEN-DOC 27086

    MATOS, I.T. ; NASCIMENTO, N.M. ; CABRERA-PASCA, G.A.; EFFENBERGER, F.B. ; FREITAS, R.S.; CARBONARI, A.W. . Investigation of magnetic and structural properties of CoFe2O4 nanoparticles by measuring hyperfine interactions with 111Cd. In: INTERNATIONAL CONFERENCE ON HYPERFINE INTERACTIONS AND THEIR APPLICATIONS, February 10-15, 2019, Goa, India. Abstract... Mumbai, India: Tata Institute of Fundamental Research, 2019. p. 35-35.

    Abstract: Because their ability of magnetic nanoparticles (MNP) to become magnetized when exposed to an external magnetic field, which make them good candidates for biomedical applications [1]. The investigation of the magnetic and structural properties by techniques with atomic resolution, such as those based on hyperfine interactions, is, therefore, greatly useful in the study of MNP. In this work, hyperfine interactions in nanoparticles of CoFe2O4 were investigated by perturbed γ-γ angular correlation (PAC) spectroscopy using 111Cd as probe nuclei in the temperature range from 50 K to 850 K. Samples of CoFe2O4 were prepared by thermal decomposition [2]. Magnetic measurements results show a blocking temperature of 210 K and a superparamagnetic behavior at 300 K. MET measurements show that particles present well-monodispersed spherical shape with average size of 7 nm. XRD results show that samples crystallize in a single phase with the expected spinel structure. PAC spectra were fitted by a model considering two site fractions occupied by the probe nuclei. One were characterized by a single well-defined Larmor frequency with site fraction population of 47%, which was assigned to probe nuclei substituting cation sites in the core region of the particles. The other was characterized by a broad distribution quadrupole frequency with population of 53% corresponding to probe nuclei at distorted cation sites in the shell region of the particles. This assignment agrees with an expected shell/core volume ratio for particles with a diameter of 7 nm. Hyperfine measurements also show that the magnetic hyperfine field (Bhf) is 12.6 T at 10 K in the saturated region and the temperature dependence of Bhf indicate that the transition temperature is around 900 K.


  • IPEN-DOC 27085

    MADI FILHO, TUFIC ; FERREIRA, ELSON B.; PEREIRA, MARIA da C.C. ; BERRETTA, JOSE R. . The use of the neutron activation analysis technique to determine heavy metals in Nicotiana tabacum solanaceae. In: INTERNATIONAL CONFERENCE ON RADIATION AND APPLICATIONS IN VARIOUS FIELDS OF RESEARCH, 6th, June 18-22, 2018, Ohrid, Macedonia. Abstract... Niš, Serbia: RAD Association, 2018. p. 348-348.

    Abstract: Tobacco addiction has been mentioned as a leading cause of preventable illnesses and premature disability and tobacco smoking is the main cause of lung cancer and one of the factors that most contribute to the occurrence of heart diseases, among others. The herbaceous species Nicotiana tabacum is a plant of the solanaceae family used for tobacco production. Some authors have researched about heavy metals and the toxicity of tobacco. Heavy metals are frequently found in low concentrations in ground, superficial and underground waters, even though it does not have environmental anthropogenic contributions. However, with the increase of the industrial activities and mining and the agrochemical use of contaminated organic and inorganic fertilizers, an alteration of the geochemical cycle occurs. As a consequence, the natural flow of heavy metals increases the release of these elements into the biosphere, where they are frequently accumulated in the superior layer of the ground, accessible to the roots of the plants. Traces of available heavy metals may be found in surface and subsurface aquatic systems and soils, even when there is no anthropogenic influence on the environment, and they frequently accumulate in the upper layer of the soil, where they are accessible to the roots of the plants. Except for the exclusion species, most plant species that grow on soil contaminated by heavy metals cannot avoid the absorption of these elements, but only limit their translocation. During planting and plant development, fertilizers and insecticides, including organochlorines and organophosphates, are used and the smoke from cigarette smoking presents various toxic substances, including heavy metals such as Chromium (Cr) and Manganese (Mn). The samples preparation procedures were carried out in our laboratories and submitted to the irradiation with thermal neutrons in the IPEN/CNEN-SP, in the IEA-R1 research reactor. The irradiated material was analyzed by gamma spectrometry using a high purity germanium detector (HPGe).


  • IPEN-DOC 27084

    RODRIGUES, ANTONIO C.I. ; MADI FILHO, TUFIC ; SILVA, DAVILSON G. da . Analysis and project of the high density storage racks for spent fuel of the research reactor IEA-R1. In: INTERNATIONAL CONFERENCE ON RADIATION AND APPLICATIONS IN VARIOUS FIELDS OF RESEARCH, 6th, June 18-22, 2018, Ohrid, Macedonia. Abstract... Niš, Serbia: RAD Association, 2018. p. 143-143.

    Abstract: The IEA-R1 research reactor works 40h weekly with 4.5 Mw power. The storage rack for spent fuel elements has less than half of its initial capacity. Under these conditions (current conditions of reactor operation 32h weekly will have 3 spend fuel by year, then, approximately 3 utilization rate Positions/year). Thus, we will have only about six years of capacity for storage. Whereas the desired service life of the IEA-R1 is at least another 20 years, it will be necessary to increase the storage capacity of spent fuel. Hence, it is necessary to double the wet storage capacity (storage in the IEA-R1 reactor’s pool). After reviewing the literature about materials available for use in the construction of the new storage rack with absorber of neutrons, the BoralcanTM (manufactured by 3M) was chosen, due to its properties. This work presents studies: (a) for the construction of new storages racks with double of the current capacity using the same place of current storages racks and (b) criticality analysis using the MCNP-5 code. Two American Nuclear Data Libraries were used: ENDF / B-VI and ENDF / B-VII, and the results obtained for each data bases were compared. These analyzes confirm the possibility of doubling the storage capacity of fuel elements burned in the same place occupied by the current storage rack attending to the IEA-R1 reactor needs and attending the safety requirements according to the National Nuclear Energy Commission – CNEN and the International Atomic Energy Agency (IAEA). To calculate the keff new fuel elements (maximum possible reactivity) used in full charge of the storage rack were considered. With the results obtained in the simulation we can conclude that doubling the amount of racks for spent fuel elements are complied with safety limits established in the IAEA standards and CNEN of criticality (keff <0.95). It is mandatory to use neutron absorber material.


  • IPEN-DOC 27083

    MARTINS, E.W. ; CARDOSO, J.V.; POTIENS, M.P.A. . Determination of computed tomography quantities using a new pediatric phantom. In: INTERNATIONAL CONFERENCE ON RADIATION PROTECTION IN MEDICINE: ACHIEVING CHANGE IN PRACTICE, December 11-15, 2017, Vienna, Austria. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2018. p. 1-5.

    Abstract: A computed tomography pediatric head phantom that uses special materials to simulate the cortical and the cancellous bone was developed. This paper shows its behavior to determine the specific computed tomography radiation quantities at two calibration laboratory, the LCI-IPEN, Brazil and LMRI-IST, Portugal. The specific quantities measured were: air kerma index(Ca,100), weighted air kerma index (Cw), average volumetric air kerma index (Cvol) and the air kerma- lenght product (PKL). The reference radiation qualities used in both laboratories were the radiation qualities recommended by the norm IEC 61267 (RQT8, RQT9 e RQT10) to computed tomography dosimetry measurements. The calculated values of CW show attenuation of 11%, 13% and 10% for the qualities RQT 8, RQT 9 and RQT 10, respectively, from cortical to cancellous bone.


  • IPEN-DOC 27082

    GERALDO, BIANCA ; VICENTE, ROBERTO ; GOES, MARCOS M. ; MARUMO, JULIO T. . Radiochemical methodology applied to determination of gamma emitting radionuclides in waste samples from IEA-R1 reactor. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 43rd, March 5-9, 2017, Phoenix, Arizona, USA. Poster... 2017.


  • IPEN-DOC 27081

    FERREIRA, EDUARDO G.A. ; MARUMO, JULIO T. ; VICENTE, ROBERTO . Proposal of a descriptive modeling of portland cement behavior under radioactive waste repository environment. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 43rd, March 5-9, 2017, Phoenix, Arizona, USA. Poster... 2017.


  • IPEN-DOC 27080

    GERALDO, BIANCA ; VICENTE, ROBERTO ; FERREIRA, ROBSON J. ; MADUAR, MARCELO F. ; GOES, MARCOS M. ; MARUMO, JULIO T. . Radiochemical method for characterization of the filter cartridges from the IEA-R1 reactor. In: ANNUAL WASTE MANAGEMENT CONFERENCE, March 6-10, 2016, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2016. p. 1-5.

    Abstract: The filter cartridges used in water purification system of the IEA-R1 research reactor become radioactive waste after the end of their useful life. The characterization of this waste is one step in their management, which aims at identifying and quantifying the radionuclides present, including those known as "difficult to measure" (DTM) radionuclides. Wastes from nuclear reactors contain fission and activation products and transuranic elements, only few of them emitting gamma radiation measurable by simple gamma spectrometry methods. In routine waste management activities, the concentrations of the DTM can only be estimated by indirect methods such as scaling factors. The method of the scaling factors uses empirically determined proportions between the concentrations of DTM radionuclides and that of easily measurable gamma emitters called key nuclides (KN), to calculate DTM concentrations. Determining the scaling factors for the filter cartridges is a hard task when the number of samples is large, not only because the preparation of samples is difficult but also because the number of radionuclides to analyze is large. If it can be demonstrated that DTM and KN are both distributed evenly in the filters, less samples from each filter are necessary, reducing lab work. The aim of this paper is to present the results of the assessment of homogeneity along the filter cartridges by gamma spectrometry of chemically reduced samples. Five thin slices of five filters were burnt and the ashes quantitatively dissolved and the activity concentration of the solutions determined by gamma spectrometry.


  • IPEN-DOC 27079

    FERREIRA, EDUARDO ; VICENTE, ROBERTO ; TURRILLAS, XABIER; YOKAICHIYA, FABIANO; FRANCO, MARGARETH ; MARTINEZ, LUIS G. ; CARVALHO, ALEXANDRE; MARUMO, JULIO T. . Effects of gamma radiation on cementitious materials in repository environment. In: ANNUAL WASTE MANAGEMENT CONFERENCE, March 6-10, 2016, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2016. p. 1-10.

    Abstract: Cementitious materials are widely used in the management of radioactive waste and have to perform as required for the period of service life of the installation. In order to assess the long term durability of cement paste in a deep borehole for radioactive wastes, specimens were casted in laboratory and exposed to a gamma radiation field. The effects of the radiation in the specimens were evaluated by X-Ray Diffraction, as changes observed in the mineralogy and microstructure of the material after irradiation doses varying between 0 (without radiation) and 10 MGy. It was observed that the specimens exposed to higher doses of gamma radiation (up to 3MGy) presented differences between surface and core, when compared with the samples with no radiation or exposed to low doses. These results are important to model the behavior of cementitious materials under the conditions expected in a borehole repository and to provide data for the safety assessment of the installation.


  • IPEN-DOC 27078

    OLIVEIRA-SILVA, T.; SUZUKI, L.C. ; LEAL, C.R.L.; KATO, I.T.; ALVARENGA, L.H.; RIBEIRO, M.S. ; PRATES, R.A.. Investigação do efeito fotodinâmico em cepas de Candida albicans pré-tratadas com glicose: estudo in vitro. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2343-2343.

    Abstract: Introdução: Candida albicans é um micro-organismo comensal presente em 80% dos indivíduos. No entanto, sua natureza oportunista pode causar severas infecções, sendo responsável por 15% dos casos de septicemia. Pode atingir indivíduos imunocompententes e imunossuprimidos, causando infecções mais graves no segundo grupo. Sua alta patogenicidade está relacionada a sua capacidade formar biofilme, uma estrutura complexa capaz de proteger C. albicans de condições ambientais desfavoráveis. O tratamento convencional com azóis não tem se mostrado eficiente devido ao aumento da expressão dos sistemas de transporte por membrana da família ABC (ATP Binding Cassette Transportes). Frente ao cenário de resistência microbiana, há necessidade de investigar novas alternativas. Uma fototerapia promissora é a terapia fotodinâmica (PDT, do inglês phodynamic therapy) que baseia-se na utilização de luz e fotossensibilizador (FS) na presença de oxigênio, formando espécies reativas de oxigênio que podem causar danos letais às células. C. albicans apresenta sensores de glicose relacionado ao seu dimorfismo (levedura-hifa), sua resposta à presença da glicose é pouco conhecida, mas acredita-se que gera um sinal intracelular que ativa os sistemas de transporte. Sendo assim, o objetivo este trabalho foi avaliar o papel da glicose ativação de uma via de entrada de fotossensibilizador para o citoplasma fúngico. Materiais e Métodos: Para o desenvolvimento do estudo, foram selecionadas as cepas ATCC 10231, YEM 13 superexpressora de poros de difusão facilitada por membrana e sua cepa selvagem YEM 12; YEM 15 superexpressora de bombas de transporte ativo e sua cepa selvagem YEM 14. C. albicans foram cultivadas aerobicamente em ágar Sabouraud e incubadas a 30°C por 24h. Os inóculos microbianos foram divididos em 4 grupos: Controle sem tratamentos; grupo irradiado sem fotossensibilizador; toxicidade do fotossensibilizador (FS) e 3 grupos PDT com irradiação de 1, 3 e 6 min. Azul de metileno na concentração final de 100μM foi utilizado como fotosensitilizador. Todos os experimentos foram realizados com e sem glicose a 50 mM. Cada experimento foi repedido pelo menos 3 vezes. Após passar pelos tratamentos, as unidades formadoras de colônia foram contadas e os dados foram submetidos à análise estatística (ANOVA) e teste de Tukey. Resultados: Os grupos irradiados sem FS não apresentaram inativação quando comparados ao grupo controle, bem como o azul de metileno não se mostrou tóxico nos parâmetros adotados no estudo. No entanto, a PDT causou morte celular proporcional a quantidade de luz entregue ao sistema. A cepa ATCC 10231 apresentou total inativação celular nos grupos com e sem glicose a partir de 3 min de irradiação. Por outro lado, as diferenças na inativação das cepas YEM 12/13 demonstram que a presença da glicose aumenta a entrada de FS e consequentemente aumenta a resposta à PDT. De maneira contrária, nas cepas YEM 14/15, a glicose promove uma espécie de proteção contra a ação da PDT. Isso pode ser relacionado à presença de bombas de transporte ativo, que com mais glicose disponível, podem bombear o FS do citoplasma. A compreensão do papel da glicose na inativação de leveduras pode elucidar mecanismos metabólicos de resposta à PDT e ser uma ferramenta importante na criação de modelos de estudos no desenvolvimento de técnicas antimicrobianas. Conclusões: A presença de glicose pode ativar a entrada de azul de metileno no citoplasma fúngico e aumentar o efeito fotodinâmico. Por outro lado, a mesma presença de glicose pode ativar bombas de efluxo na membrana da levedura e expulsar fotossensibilizador de dentro do fungo.


  • IPEN-DOC 27077

    YOSHIKAWA, H.Y.; FERREIRA, E.S.; ZEZELL, D.M. ; LINS, E.C.C.C.; ANA, P.A.. Mudanças na fluorescência da dentina promovidas pelo laser de Er,Cr:YSGG e desafio cariogênico. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2338-2338.

    Abstract: Introdução: Diante da alta prevalência de lesões de cárie radicular, observada principalmente entre a população idosa, e a rápida progressão destas lesões [1], o que pode ocasionar a perda do elemento dental, faz-se necessária a adoção de métodos preventivos e de diagnóstico precoce efetivos, de forma que a progressão destas lesões seja monitorada e devidamente evitada. Neste aspecto, métodos ópticos baseados em lasers e LEDs tem se mostrado bastante promissores, pois possibilitam a modificação química dos tecidos duros dentais, tornando-os menos susceptíveis à perda mineral [2], assim como permitem o monitoramento das lesões incipientes de cárie de forma não invasiva, em tempo real e sem o uso de radiação ionizante [3]. Assim, o presente trabalho objetiva avaliar e monitorar os efeitos do laser de Er,Cr:YSGG na prevenção do surgimento de lesões de cárie na dentina por meio de um sistema de imageamento por fluorescência. Material e Método: 75 blocos de dentina radicular bovina foram aleatoriamente distribuídos em 5 grupos experimentais com 15 amostras cada: sem tratamento (controle negativo); com aplicação tópica de flúor fosfato acidulado - FFA (controle positivo); irradiadas com laser de Er,Cr:YSGG ( = 2,78 μm, 6 J/cm2, 20 Hz, 12,5 mJ/pulso, 0,25 W); irradiadas e seguida da aplicação de FFA e, por fim, com aplicação de FFA seguida da irradiação laser. Tais amostras foram submetidas a uuma ciclagem de pH por 8 dias, visando-se criar uma lesão incipiente de cárie. As amostras foram avaliadas por um sistema de imagens de fluorescência (SIF), baseado em uma roda mecânica com filtros ópticos banda-larga ( de corte = 450 nm), e outros com  = 500, 550 e 600 nm, uma câmera CCD científica, uma lente objetiva e um sistema de iluminação composto por LEDs ( = 405±30 nm) controlados por computador. Em todas as medidas, uma amostra de cerâmica foi mantida como amostra de referência, sendo posicionada lateralmente, em posição padronizada, à. A análise da intensidade de fluorescência de cada amostra foi obtido empregando-se o componente G do sistema RGB, empregando-se rotina desenvolvida em MatLab. O valor da intensidade de fluorescência de cada amostra foi calculado empregando-se um índice, obtido pela subtração entre o valor da amostra teste e da referência. Os dados foram analisados estatisticamente, considerando nível de significância estatística de 5%. Resultados: Quando empregados os filtros de  = 500, 550 e 600 nm, observou-se redução da intensidade de fluorescência do grupo que recebeu apenas a irradiação com laser de Er,Cr:YSGG em relação aos grupos controle positivo e negativo, sendo esta redução estatisticamente significativa (p = 0,04) quando observada com filtro de 600 nm. Observou-se aumento significativo (p = 0,03) da intensidade de fluorescência nos grupos com associação de tratamentos, sendo o grupo irradiado com posterior aplicação de FFA o que apresentou maior intensidade. Não se observou diferença estatisticamente significativa entre os grupos experimentais quando avaliados utilizando-se o filtro banda larga (p > 0,05). Conclusões: Os resultados obtidos corroboram a hipótese de que a irradiação da dentina radicular com laser de Er,Cr:YSGG pode promover mudanças na composição química da dentina, assim como na sua rugosidade por meio de micro-ablações, o que modifica a fluorescência do tecido irradiado. Ainda assim, considerando o comprimento de onda dos filtros utilizados, observa-se que a diminuição da fluorescência pode ser decorrente do aumento da perda mineral do tecido. Desta forma, de acordo com os resultados obtidos, pode-se concluir que a associação dos tratamentos (laser e FFA) parece ser a alternativa mais promissora para prevenção da desmineralização da dentina, e que o sistema de imagens de fluorescência, com os filtros empregados, trata-se de um método eficiente para avaliação da eficiência dos tratamentos propostos no surgimento das lesões de cárie radicular.


  • IPEN-DOC 27076

    SANTOS JUNIOR, S.L.; FERREIRA, E.S.; BENETTI, C.; AMARAL, M.M. ; ZEZELL, D.M. ; GOMES, A.S.L.; ANA, P.A.. Avaliação dos efeitos do laser de Er,Cr:YSGG na dentina por tomografia por coerência óptica. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2337-2337.

    Abstract: Introdução: Mesmo com formas de tratamento bastante conhecidas, as doenças que envolvem os tecidos duros da cavidade oral ainda são bastante prevalentes, o que demonstra a necessidade de se continuar a busca por novos métodos de diagnóstico e prevenção. A literatura mostra possibilidades promissoras relacionadas à utilização dos lasers de alta intensidade para prevenção da cárie [1], tendo em vista o aquecimento promovido pelos mesmos [2]. Por outro lado, o diagnóstico de lesões de cárie em estágios iniciais possibilita a adoção de procedimentos para paralisar as mesmas. Os métodos baseados em biofotônica podem auxiliar neste processo, considerando os bons resultados reportados tanto para prevenção das lesões, empregando-se lasers em alta intensidade, quanto para diagnóstico óptico, empregando-se radiação não ionizante. A técnica de tomografia por coerência óptica (OCT) fornece imagens transversais de estruturas através de imageamento óptico, não é invasiva e não utiliza radiação ionizante[3]. Neste sentido, este estudo objetiva avaliar o efeito do laser de Er,Cr:YSGG para prevenção do surgimento de lesões de cárie radicular, assim como avaliar o potencial da OCT no monitoramento da progressão desta lesões. Material e Método: Foi conduzido um estudo in vitro cego com 75 blocos de dentina radicular de 2 x 2 x 4 mm, os quais foram aleatoriamente distribuídos em 5 grupos experimentais (n=15): G1 – sem tratamento, G2 – grupo tratado com flúor fostato acidulado (FFA – 1,23% F, pH 3,3 – 3,9, por 4 minutos – controle positivo), G3 – grupo irradiado com laser de Er,Cr:YSGG (l = 2,78 μm, 20 Hz, 6 J/cm2, sem refrigeração), G4 – grupo irradiado seguido da aplicação de FFA, G5 – grupo tratado com FFA seguido da irradiação laser. As amostras foram submetidas a um desafio cariogênico in vitro por meio de ciclagem de pH com duração de 8 dias. Após, as amostras foram avaliadas por tomografia por coerência óptica (OCT Callisto, l = 930 nm, Thorlabs Inc., Estados Unidos), em que foram realizados 5 escaneamentos equidistantes por amostra ao longo eixo das lesões formadas. Depois da aquisição das imagens, foi calculado o coeficiente de atenuação óptica a partir do decaimento exponencial da intensidade da luz retroespalhada de todos os grupos, utilizando-se rotina desenvolvida em software MatLab. A análise estatística foi executada empregando-se o teste estatístico de Kruskal-Wallis e Student-Newman-Keuls, considerando-se o nível de significância estatística de 5%. Resultados: Nenhum dos tratamentos pospostos apresentou desgaste da superfície após desafio cariogênico. Observouse que o grupo irradiado apresentou coeficiente de atenuação óptica (13,6 ± 1,57 μm-1) significativamente maior (p < 0,05) que os demais grupos experimentais. Os demais grupos apresentaram os seguintes valores de coeficiente de atenuação óptica: G1: 12,72 ± 0,98 μm-1 12,65 ± 0,92 μm-1 12,6 ± 1,4 μm-1 12,76 ± 1,15 μm-1. Desta forma, os outros grupos, quando comparados entre si, não diferiram estatisticamente. Conclusões: A irradiação da dentina com laser de Er,Cr:YSGG isoladamente possibilitou a redução da desmineralização, evidenciada pelo aumento do coeficiente de atenuação óptica. Ainda assim, a tomografia por coerência óptica apresenta-se como uma técnica promissora para avaliação dos efeitos da irradiação laser sobre as lesões incipientes de cárie.


  • IPEN-DOC 27075

    SANTOS, G.L.; SANTUCCI, G.; OLIVEIRA-SILVA, T.; PRATES, R.A.; RIBEIRO, M.S. ; KATO, I.T.. Alteração da susceptibilidade de C. albicans resistente ao fluconazol após terapia fotodinâmica. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2336-2336.

    Abstract: Introdução: As doenças infecciosas causadas por fungos ainda representam um grande desafio para os profissionais de saúde e a comunidade científica, especialmente as infecções causadas por micro-organismos resistentes aos fármacos antifúngicos convencionais. Novas alternativas de tratamento foram estudadas, entre elas a terapia fotodinâmica (PDT) que surgiu como uma promissora modalidade terapêutica por causar a morte de micro-organismos a partir da associação de um fotossensibilizador e luz. Recentemente observamos que a PDT realizada em condições subletais aumenta a suscetibilidade do fungo Candida albicans ao fluconazol [1]. Dando continuidade a este estudo iniciamos a investigação em C. albicans que apresentam diferentes mecanismos de resistência aos antifúngicos. Assim, o presente trabalho teve o objetivo de avaliar o efeito antimicrobiano da associação de PDT e fluconazol em C. albicans que apresenta um sistema de efluxo responsável pela resistência ao antifúngico. Materiais e Métodos: Para a realização deste trabalho foi utilizado C. albicans YEM 13, uma cepa com expressão exacerbada de bomba de efluxo da família MFS (Major Facilitator Superfamily). As células foram submetidas a PDT com azul de metileno na concentração final de 50 μM e irradiadas com parâmetros subletais (=660 nm, 75 mW/cm2, 4 min)[1]. Para investigar a atividade antimicrobiana do fluconazol foram determinados os valores de concentração mínima inibitória (CMI) do crescimento celular. A CMI foi determinada pelo método de microdiluição em caldo de acordo com as normas estabelecidas pelo Comitê Europeu de Teste à Susceptibilidade Antimicrobiana (EUCAST)[2]. A solução de fluconazol (Sigma Aldrich, São Paulo, Brasil) foi preparada, considerando a potência do fármaco de 98% e a faixa de concentrações testadas foi de 0,125-64 μg/mL. Os valores de CMI foram determinados por meio da leitura da absorção em 530 nm, em espectrofotômetro (SpectraMax M4, Molecular Devices, EUA). Para cada grupo foi determinada a menor concentração da droga que promoveu a inibição ≥ 50% do crescimento em comparação ao controle livre de drogas. Foram avaliadas células C. albicans YEM 13 sem tratamento e previamente submetidas a PDT subletal. Foi utilizado como controle a cepa de C. albicans ATCC 90028 que não apresenta resistência ao fluconazol. Resultados: C. albicans ATCC 90028 apresentou valor de CMI de 0,5 μg/mL, dado compatível com os descritos na literatura. As amostras de célula YEM 13 que não foram submetidas à PDT apresentaram o valor de CMI de 64 μg/mL, que também coincide com o valor descrito na literatura [3]. Estes dados demonstram que a cepa YEM 13 apresenta um valor de CMI 128 vezes superior ao de uma cepa suscetível ao fluconazol (ATCC 90028). Confirmando nossa hipótese, o fluconazol foi mais ativo em C. albicans submetida previamente à PDT subletal. Dentro da faixa de 0,125-64 μg/mL, houve maior inibição do crescimento celular quando previamente submetido à PDT, resultando na redução do valor de CMI de 64 μg/mL para 32 μg/mL. Conclusões: Foi possível demonstrar que a PDT pode aumentar a susceptibilidade ao fluconazol em cepa de C. albicans que apresentam bombas de efluxo da família MFS. Estes resultados preliminares sugerem que a associação terapêutica entre a PDT e o fluconazol pode ser uma importante alternativa no tratamento de infecções por cepas de C. albicans que apresentam resistência a este antifúngico. Vale ressaltar que neste trabalho foram utilizadas condições subletais e resultados ainda mais promissores podem ser obtidos com a otimização dos parâmetros de irradiação.


  • IPEN-DOC 27074

    LEAL, C.R.L.; SILVA, T.O.; ALVARENGA, L.H.; BUSSADORI, S.K.; RIBEIRO, M.S. ; KATO, I.T.; PRATES, R.A.. Aplicação da terapia fotodinâmica com uso do LED e azul de metileno em Streptococcus mutans: estudo in vitro. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2333-2333.

    Abstract: Introdução: Streptococcus mutans é considerado como colonizador primário para o desenvolvimento da cárie dentária. As propriedades cariogênicas de S. mutans são reguladas por diversos genes, envolvidos em vias metabólicas essenciais: adesão microbiana, formação do biofilme, síntese de polissacarídeo extracelular, captação de carboidratos e tolerância ao ácido. S. mutans normalmente habita um biofilme complexo. A bactéria produz uma grande quantidade de exopolissacarídeos, principalmente na presença da glicose facilitando o processo de adesão e ativando bombas de transporte que podem facilitar a entrada aumentando o acúmulo do fotossensibilizador dentro da célula [1]. A terapia fotodinâmica envolve a utilização de um fotossensibilizador (FS), que é absorvido por células específicas seguida de irradiação com luz visível, resultando na morte celular [2]. Este trabalho tem o objetivo de investigar a morte celular do Streptococcus mutans após a terapia fotodinâmica com azul de metileno e LED com e sem glicose. Material e Metodologia: Neste trabalho o Streptococcus mutans foi cultivado em microaerofilia em ágar infusão de cérebro e coração (BHI) incubado a 37o por 48 horas. Os inóculos foram preparados com a coleta de colônias puras que foram suspensas em solução salina fosfatada tamponada (PBS) com e sem 50 mM de glicose. O fotossensibilizador azul de metileno foi adicionado à suspensão proporcionando a concentração final de 100 μM. Todos os experimentos foram realizados com 6 grupos diferentes (grupo controle; grupo irradiado com LED sem FS; grupo FS sem irradiação; e grupos PDT). Os tempos de irradiação do grupo PDT foram de 30,, 60 e 120 segundos. Os resultados foram submetidos à análise estatística com teste de variância one-way (ANOVA). A comparação entre as médias foi realizada pelo teste de Tukey e a significância foi ajustada em 5%. Resultados: A irradiação somente com luz não apresentou morte celular, assim como o fotossensibilizador não apresentou toxicidade no escuro, pois, o grupo controle não apresentou diferenças significativas quando comparado com os grupos luz e fotossensibilizador em todos os experimentos com e sem glicose. Em contrapartida nos experimentos sem glicose a PDT provocou morte celular proporcional a quantidade de luz empregada. Quanto maior a exposição radiante, maior foi a inativação do S. mutans. Após 2 min. de irradiação observamos redução de 100% das bactérias, apresentando uma redução de 7 ordens de grandeza em relação ao grupo controle. Nos experimentos com glicose não foi observada morte celular mesmo aumentando a exposição radiante após 2 min. de irradiação. Conclusão: Podemos concluir que a PDT é uma solução viável para inativação de S. mutans em suspensão, e que a presença da glicose reduz drasticamente o efeito da PDT..


  • IPEN-DOC 27073

    SOUZA, E.R.L.B. de; ALVARENGA, L.H.; LEAL, C.R.L.; LEITE, C.G.; PEREIRA, T.R.; VIEIRA, D.C.; PRETTO, L. de ; FREITAS, A.Z. de ; FERNANDES, A.U.; PRATES, R.A.. Terapia fotodinâmica antimicrobiana combinada ao tratamento periodontal em ratos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2332-2332.

    Abstract: Introdução: A Terapia Fotodinâmica antimicrobiana (aPDT) vem sendo utilizada como adjuvante ao tratamento da periodontite. Ela combina um fotossensibilizador (FS) e fonte de luz para produzir espécies reativas de oxigênio e matar células microbianas [1]. A PpNetNI é um derivado da protoporfirina, e tem um sítio de ligação química no biofilme e grande afinidade às células microbianas. Este estudo tem como objetivo investigar os efeitos da aPDT como adjuvante ao tratamento da periodontite. Materiais e Métodos: Este estudo (aprovado pelo Comitê de Ética da UNINOVE AN0029/2015) incluiu 18 ratos machos Wistar saudáveis (Rattus norvegicus). A periodontite foi induzida pela inserção de uma ligadura de algodão em posição subgengival no primeiro molar inferior. O primeiro molar inferior contralateral não recebeu a ligadura ou nenhum tipo de tratamento, e foi utilizado como controle. Após 7 dias, a ligadura foi removida e todos animais receberam raspagem e alisamento radicular (RAR) [2]. Os grupos (n=3) foram então divididos em: 1) grupo RAR (receberá RAR e irrigação com PpNetNI, 10 μM, sem irradiação) e 2) grupo PDT (irrigado com PpNetNI 10 μM seguido de irradiação com LED durante 90 s). Para irradiação foi utilizado um LED emitindo comprimento de onda de 630 nm com potência radiante de 400 mW (irradiância - 200 mW/cm2; exposição radiante - 18 J/cm2). As avaliações foram realizadas 24 h, 48 h e 7 dias após a intervenção e para isto, 3 animais de cada grupo foram eutanasiados em cada momento experimental. A área de perda óssea na região vestibular do primeiro molar inferior foi avaliada por Tomografia de Coerência Óptica (OCT, THORLABS LTD., Ely, UK). Os dados foram submetidos à análise estatística (teste Mann-Whitney, p˂0.05). Até o momento foram avaliados 6 animais, que foram tratados conforme descrito e eutanasiados 7 dias após o término do tratamento. Resultados: Dentre os animais que foram eutanasiados 7 dias após o término do tratamento, os animais do grupo PDT mostraram um ganho ósseo de aproximadamente 30% quando comparados ao grupo RAR. A OCT foi capaz de detectar a perda óssea nas amostras e foi um método não destrutivo para este modelo experimental. Conclusões: Com os dados obtidos até o momento e com os parâmetros utilizados neste estudo podemos concluir que a aPDT foi uma alternativa eficaz em garantir a saúde periodontal e foi capaz de regenerar os tecidos de suporte periodontal.


  • IPEN-DOC 27072

    AMARAL, M.M. ; TEIXEIRA, L.R.C. ; CARVALHO, M.T.; GOMES, A.S.L.; ZEZELL, D.M. . Avaliação da espessura da epiderme em hemangioma por optical coherence tomography. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Resumo... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 2331-2331.

    Abstract: Introdução: Os Hemangiomas são lesões vasculares que comumente encontradas na região da cabeça e pescoço, atingindo cerca de 10% das crianças ao redor do mundo [1]. O diagnóstico precoce pode levar ao tratamento das lesões e redução de suas consequências estéticas e psicológicas causadas ao paciente. A biopsia excisional é o padrão ouro para diagnostico a nível celular, porém é uma técnica invasiva e que pode causar efeitos colaterais. As alternativas não invasivas disponíveis são a tomografia computadorizada (CT), a imagem por ressonância magnética (MRI) e o ecografia por ultrassom (US) [1, 2]. Tanto o CT quanto o MRI apresentam um custo proibitivo para aplicações clínicas de rotina. Já o US está presente em hospitais e possui custo mais acessível com aplicações no diagnóstico vascular. A imagens US atinge camadas profundas com resolução e alguns milímetros no do tecido biológico, não atendendo aos hemangiomas que aparecem nas camadas mais superficiais da pele. Uma possível alternativa é a técnica Optical Coherence Tomography (OCT) que produz imagens em seção transversal com resolução micrométrica do tecido biológico utilizando luz. Ela encontra aplicações na dermatologia [3] e pode ser usado para caracterização funcional, óptica ou morfológica de tecido biológico. O objetivo deste trabalho foi avaliar as diferenças de espessura da epiderme em regiões de lesão vascularizada e normal utilizando a técnica OCT. Materiais e Métodos: As imagens OCT foram adquiridas utilizando-se um sistema OCT swept source com resolução axial de 9 μm e lateral de 18 μm. As imagens possuem 512x1024 pixel (axial x lateral) e foram adquiridas a uma taxa de 25 quadros / s. Este estudo foi aprovado pelo Comitê de Ética do IMIP (protocolo no. 728.993). Neste estudo fo ram utilizadas imagens da mão de um paciente nas regiões de hemangioma e pele sadia, possibilitando a identificação de suas diferenças. Foi implementado um algoritmo em ambiente Matlab para determinar a espessura da epiderme em todas as 541 imagens de lesão vascularizada e as 50 de pele normal. Resultados: Através da medição automatizada da espessura da epiderme na região de lesão e sadia (figura 1) foi possível observar a distribuição de profundidade em cada uma destas regiões. A região de lesão possui uma distribuição de profundidade mais estreita e com espessura menor que a de pele normal. Já a região de pele normal apresenta uma distribuição mais larga, porém com dois valores de maior probabilidade, isso se deve tanto a presença de glândulas mais visíveis na pele sadia quanto a uma maior presença de papilas dérmicas na junção derme-epiderme. Conclusões: A medição da espessura da epiderme mostrou-se válida como um possível marcador da presença de hemangioma. O uso desta abordagem poderia ser complementar a outros marcadores possíveis de serem extraídos do sinal OCT. A ampliação do painel de estudo e comparação com outras técnicas padrão ouro deverá ser realizada em futuros estudos.


  • IPEN-DOC 27071

    FERREIRA, E.S.; BENETTI, C.; ZEZELL, D.M. ; KATO, I.T.; ANA, P.A.. Efeitos da irradiação com laser de Er,Cr:YSGG na temperatura pulpar e superficial da dentina radicular. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1937-1940.

    Abstract: Tendo em vista o envelhecimento da população e a permanência dos dentes na cavidade oral, observou-se um aumento da incidência da cárie radicular em idosos. Os lasers de érbio podem ser usados para prevenção de cárie; contudo, ainda não são estabelecidos parâmetros de irradiação que sejam seguros para os tecidos pulpares e periodontais e que sejam efetivos para ocasionar alterações químicas na superfície da dentina. Este estudo avaliou os efeitos da irradiação da dentina radicular com laserde Er,Cr:YSGG na temperatura pulpar e superficial da dentina, buscando-se determinar parâmetros de irradiação seguros e efetivos para futura aplicação clínica. Para tal, foi realizado um estudo in vitro randomizado com duas fases experimentais. Na primeira fase, 30 blocos de dentina radicular bovina foram empregados para avaliar a temperatura superficial ocasionada por um único pulso laser empregando-se termografia no infravermelho, enquanto que, na segunda fase experimental, 30 dentes incisivos inferiores humanos foram empregados para avaliação da temperatura pulpar durante as irradiações por 10 segundos empregando-se termopares de resposta rápida. As irradiações foram efetuadas com laser de Er,Cr:YSGG,  = 2,78 μm, 20 Hz, sem refrigeração, com potências médias de 0,1 W, 0,25 W e 0,5 W, o que resultou em densidades de energia de 2,4 J/cm2, 6 J/cm2 e 12 J/cm2, respectivamente. Observou-se variações de temperatura superficial de 61  26 oC, 75  34 oC e 172  36 oC para os grupos irradiados com potência média de 0,1 W, 0,25 W e 0,5 W, respectivamente. Foram registradas elevações médias de temperatura pulpar de 0,81 ± 0,4 oC, 1,76 ± 0,7 oC e 2,95 ± 1,33 oC, para os grupos irradiados com potência média de 0,1 W, 0,25 W e 0,50 W, respectivamente. Concluiu-se que o laser de Er,Cr:YSGG promove elevações de temperatura superficiais que indicam a ocorrência de transformações químicas na superfície da dentina radicular; contudo, dos parâmetros testados, se considerarmos as elevações de temperatura pulpar, a potência média de 0,25 W é a que se apresenta mais promissora para futuro uso para prevenção da cárie radicular.


  • IPEN-DOC 27070

    GONÇALVES, KARINA de O.; SILVA, MONICA N. da; COURROL, LILIA C. . Síntese de nanopartículas de ouro funcionalizadas com ácido aminolevulínico e laser de pulsos ultracurtos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1913-1916.

    Abstract: As nanopartículas de ouro apresentam inúmeras aplicações na medicina. As diferenças de tamanho, forma e propriedades de superfície, fazem com que suas aplicações se tornem versáteis, como por exemplo, a terapia fototérmica e o rastreamento de tumores (biomarcadores). Foi recentemente demonstrado na literatura que a incorporação de nanopartículas de ouro na estrutura do ácido 5-aminolevulínco (5-ALA) melhora as propriedades fotodinâmicas do fármaco. O estudo com laser ocorreu visando à possibilidade de modificação no formato das nanopartículas, de esféricas para outras formas, entre elas bastões e prismas que resultam em bandas de plasmons de comprimentos de onda maiores, uma vez que nanopartículas com formato mais cilíndrico apresentam uma janela na região da janela óptica do tecido biológico e desta forma a luz aplicada em PDT teria maior profundidade de penetração no tecido. Assim propomos neste estudo, sintetizar nanopartículas de ouro com 5-ALA, para realizar o diagnóstico e a terapia (Teranóstica) de doenças com crescimento não controlável, de uma forma mais simples, menos invasiva e mais barata.


  • IPEN-DOC 27069

    PROVASI, C.; CASSIMIRO-SILVA, P.F.; ANA, P.A. da; ZEZELL, D.M. ; GOMES, A.S.L.; LINS, E.C.. Estudo da espectroscopia de reflexão com radiações visíveis e infravermelhas para discriminação de tecidos pulpares humanos sadios e patológicos. In: VIEIRA NETO, HUGO (Ed.); SOARES, ALCIMAR B. (Ed.); FÉLIX, RODRIGO P.B. da C. (Ed.); VIEIRA NETO, HUGO (Org.); MAIA, JOAQUIM M. (Org.); PICHORIM, SÉRGIO F. (Org.); GAMBA, HUMBERTO R. (Org.); COSTA, EDUARDO T. (Org.) CONGRESSO BRASILEIRO DE ENGENHARIA BIOMÉDICA, 25., 17-20 de outubro, 2016, Foz do Iguaçu, PR. Anais... Rio de Janeiro, RJ: Sociedade Brasileira de Engenharia Biomédica, 2016. p. 1909-1912.

    Abstract: A polpa dental é o tecido mais interno do dente. Sua principal função é garantir a dentinogênese e a sensibilidade dental, e por essa razão a informação clínica sobre a saúde da polpa é relevante. Polpas diagnosticadas como não-vitais são encaminhadas para um tratamento endodôntico agressivo, baseado na remoção de todo tecido degradado. Por esse motivo, deve-se haver um esforço em minimizar o número de falsos diagnósticos clínicos da vitalidade pulpar, na intenção de preservar a integridade do paciente. Esse estudo propõe a espectroscopia no visível e no infravermelho como método de melhorar a precisão no diagnóstico do status pulpar. Ele é baseado em confrontar a reflexão óptica dos tecidos no espectro do visível (VIS) e do infravermelho próximo (NIR) (350nm a 1.700nm) no intuito de discriminar polpas humanas vitais de outras polpas sintomáticas de pulpite. A Análise dos Componentes Principais (PCA) sobre os espectros de reflexão ainda propôs modelos matemáticos de diferenciação dos grupos. Os resultados revelaram que a reflexão óptica pode discriminar o status da vitalidade de polpas humanas vivas; e a análise estatística da PCA revelou precisão de acerto de 100% para radiações NIR e 95% para radiações VIS.


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

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

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

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

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


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).



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.