Repositório Digital - IPEN/SP: Recent submissions

  • IPEN-DOC 25094

    FREIRE, LUCIANO O. ; ANDRADE, DELVONEI A. de ; MONTERRAIN, DANIEL. A system status definition to improve behavior description in specifications based on constructal law. Open Journal of Applied Sciences, v. 8, n. 8, p. 315-337, 2018. DOI: 10.4236/ojapps.2018.88024

    Abstract: System behavior description using states faces problems like state explosion, lack of clear definition of state, state identification and coordination between multiple agents. The goals of this work are to ease design activity, to reduce engineering efforts, and to mitigate project risks. The proposed way is to improve information flow during design by adding definitions and some protocols or rules for communicating a specification or design description. This work presented an objective definition of system status (way of interaction with the rest of the world) along other concepts. This work focused in definitions as mind entities and their importance to rationalize work and mitigate project risks during design. This article presented some simple examples to illustrate the advantages of each aspect of proposed definition of system status and discussed limits and exceptions for such definition. The key finding was the proposed definition which was the simplest while keeping completeness at a given product breakdown level. Such definition of status enforced formal segregation of needs and solutions, and eased the inclusion of behavior definition in specifications.

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  • IPEN-DOC 25093

    FERREIRA, JOAO C. ; CAVALLARI, ROGER V. ; BERGAMASCHI, VANDERLEI S. ; ANTONIASSI, RODOLFO M. ; TEIXEIRA-NETO, ANGELA A.; LINARDI, MARCELO ; SILVA, JULIO C.M.. Palladium nanoparticles supported on mesoporous biocarbon from coconut shell for ethanol electro‑oxidation in alkaline media. Materials for Renewable and Sustainable Energy, v. 7, n. 4, 2018. DOI: 10.1007/s40243-018-0130-z

    Abstract: Palladium nanoparticles supported on carbon Vulcan XC72 (Pd/C) and biocarbon (Pd/BC) synthesized by sodium borohydride process were used as catalysts for ethanol electro-oxidation in alkaline media. The biocarbon (BC) from coconut shell with mesoporous and high surface area (792 m2 g−1) was obtained by carbonization at 900 °C and the hydrothermal treatment in a microwave oven. The D-band and G-band intensity ratio (ID/IG) from Raman analysis showed high disorder of the biocarbon, while X-ray photoelectron spectroscopy (XPS) suggests higher percentage of oxygen groups on the surface of biocarbon than of Vulcan XC72. From X-ray diffraction (XRD), it was observed peaks in 2θ degree related to the face centered cubic (fcc) structure of palladium and the mean crystallite sizes calculated based on the diffraction peak of Pd (220) were 5.6 nm for Pd/C and 5.3 nm for Pd/BC. Using Transmission Electron Microscope (TEM), it was observed particles well dispersed on both carbons support materials. The electrocatalytic activity of the materials was investigated by cyclic voltammetry (CV) and chronoamperometry (CA) experiments. The peak current density (on CV experiments) from ethanol electro-oxidation on Pd/BC was 50% higher than on Pd/C, while the current density measured at 15 min of CA experiments was 80% higher on Pd/BC than on Pd/C. The higher catalytic activity of Pd/BC might be related to the large surface area of the biocarbon (792 m2 g−1) vs (239 m2 g−1) of Vulcan carbon, the defects of the biocarbon structure and higher amount of oxygen on the surface than Carbon Vulcan XC 72.

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  • IPEN-DOC 25092

    FEITOSA, SABRINA A.; CAMPOS, FERNANDA; YOSHITO, WALTER K. ; LAZAR, DOLORES R.R. ; USSUI, VALTER ; VALANDRO, LUIZ F.; BOTTINO, MARCO A.; BOTTINO, MARCO C.. Effect of the bonding strategy on the tensile retention of full-contour zirconia crowns. International Journal of Adhesion and Adhesives, v. 85, p. 106-112, 2018. DOI: 10.1016/j.ijadhadh.2018.06.006

    Abstract: This study evaluated the effect of distinct bonding strategies on the retention of full-contour zirconia ceramic (YTZP, FCZ) crowns, and it characterized some physicochemical and mechanical properties of FCZ ceramic and its corresponding glazing system. To evaluate retention strength, dies were made with a dentin-analogue material to simulate a prepared tooth. FCZ crowns were manufactured using CAD-CAM technology and allocated into groups according to the bonding strategy: no ceramic treatment (PF – Panavia F cementation), glaze (GL), tribochemical silica coating (CJ), CJ + GL, and piranha solution followed by glaze (PS + GL). The specimens were subjected to thermocycling and storage in distilled water for 100 days before the retention tests. FCZ presented a porosity volume fraction of 0.2%, an apparent density of 6.06 g/cm3, Vickers hardness of 12.4±0.07 GPa, and fracture toughness of 5.54±0.24 MPam1/2. SEM revealed a homogeneous microstructure composed of submicron-sized grains. XRD identified mainly zirconia's tetragonal phase. Glaze powder morphology was observed to be irregular, with a nanometric particle size, and a diffraction pattern characteristic of an amorphous material with several peaks of leucite. The PF and GL groups had higher retention values. The majority of the groups presented pre-test bonding failures, and two catastrophic failures of the FCZ-crown (GL and PF groups) were noted. The use of an MDP-containing resin cement or glaze application might improve retention of the FCZ crowns.

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  • IPEN-DOC 25090

    FALCAO, R.B. ; DAMMANN, EDGAR D.C.C. ; ROCHA, C.J. ; DURAZZO, M. ; ICHIKAWA, R.U. ; MARTINEZ, L.G. ; BOTTA, W.J.; LEAL NETO, R.M. . An alternative route to produce easily activated nanocrystalline TiFe powder. International Journal of Hydrogen Energy, v. 43, n. 33, p. 16107-16116, 2018. DOI: 10.1016/j.ijhydene.2018.07.027

    Abstract: In this paper, an alternative process route to produce active nanocrystalline TiFe compound was investigated. First, TiH2 and Fe powders were dry co-milled in a planetary ball mill for 5e40 h. TiH2 was selected as precursor powder, instead of Ti powder, due its fragility, which has proved to be beneficial to decrease powders adherence on milling tools. In terms of loose powder mass, milling yields ranged from 90 to 95 wt.%. Next, milled powders were post-heated at 873 K under dynamic high-vacuum for TiFe synthesis reaction. First hydrogen absorption was verified in situ during the cooling process of samples (until the room temperature), being the amount of hydrogen absorbed and desorbed by this samples measured by automated Sievert's apparatus, under constant hydrogen flow rate of 9 cm3. min-1 (dynamic measurements). Besides to allowing the first absorption in situ, the investigated process route also allowed the production of the non-stoichiometric TiFe compound (rich in Ti) in samples milled for shorter times (5 and 10 h), both characteristics associated with maintaining the mechanical compound activity. Each sample absorbed hydrogen at 2 MPa during the cooling process, requiring no additional thermal activation cycles, since the samples milled for shorter times (mainly for 10 h) could absorb hydrogen for the first time more easily. However, the samples milled for longer times (25 and 40 h) shown better results in terms of reversible and storage capacities (0.73 and 0.94 wt.%, respectively).

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  • IPEN-DOC 25089

    ESTEVES-PEDRO, NATALIA M.; SUGIBAYASHI, KENJI; OSTROSKY, ELISSA A.; FERRARI, MARCIO; SUFI, BIANCA da S. ; MATHOR, MONICA B. ; MORENO, PAULO R.H.; LOURENCO, FELIPE R.; CONSIGLIERI, VLADI O.; BABY, ANDRE R.; KANEKO, TELMA M.. Validation cytotoxicity assay for lipophilic substances. Current Topics in Medicinal Chemistry, v. 18, n. 4, p. 275-286, 2018. DOI: 10.2174/1568026618666180410142829

    Abstract: It is challenging to disperse lipophilic substances in a validated cytotoxicity assay, especially for compounds with log K-ow greater than or equal to 5 that may show false negative results. The purpose of this study was to explain the challenges in conducting a cytotoxicity validated test of lipophilic substances: Minthostachys setosa, Pimenta pseudocaryophyllus, and Drimysbrasiliensis essential oils. Additionally, we compared the equivalence of Neutral Red (NR) and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl) -2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) in detecting cell viability. The Hydrophile-Lipophile Balance (HLB) technique was used to evaluate the dispersion of essential oils and cytotoxicity in accordance to the guidelines of the OECD / GD 129 validated cytotoxicity assay. We compared the equivalence of vital dyes by TOST equivalence test. According to the results, we demonstrated the possibility of using other ways to disperse the lipophilic substances. Based on the HLB theory, we selected polysorbate 20 as the best solubilizing agent of the essential oils studied in D10 culture medium

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  • IPEN-DOC 25088

    DURAZZO, MICHELANGELO ; FREITAS, ARTUR C. ; SANSONE, ALBERTO E.S. ; FERREIRA, NILDEMAR A.M. ; CARVALHO, ELITA F.U. de ; RIELLA, HUMBERTO G. ; LEAL NETO, RICARDO M. . Sintering behavior of UO2-Er2O3 mixed fuel. Journal of Nuclear Materials, v. 510, p. 603-612, 2018. DOI: 10.1016/j.jnucmat.2018.08.051

    Abstract: The incorporation of burnable neutron absorbers into nuclear fuel pellets is important regarding reactivity compensation, which enables longer fuel cycles. The dry mechanical blending route is the most attractive process to accomplish absorbers incorporation because of its simplicity. By using this route, the present work has investigated the sintering behavior of UO2Er2O3 mixed fuel. A comparison with UO2Gd2O3 sintering behavior was presented. The behavior of UO2Er2O3 fuel sintering was similar to that reported for UO2Gd2O3 fuel, e.g. two-stage sintering with two peaks in the shrinkage rate curves. The effect showed to be less pronounced for Er2O3. This was attributed to the characteristics of the Er2O3 powder particles used as raw-material, whose agglomerates can be more easily broken and thus better homogenized during the blending with UO2 powder. These results confirmed that sinterability depends directly on the quality of the homogenization of the powders, as seen previously. A second phase was experimentally detected in the UO2Er2O3 system, but its impact on the sintering behavior of this mixed fuel has not yet been clarified.

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  • IPEN-DOC 25087

    DONATUS, UYIME ; VIVEIROS, BARBARA V.G. de ; ALENCAR, MAICON C. de ; FERREIRA, RAPHAEL O.; MILAGRE, MARIANA X. ; COSTA, ISOLDA . Correlation between corrosion resistance, anodic hydrogen evolution and microhardness in friction stir weldment of AA2198 alloy. Materials Characterization, v. 144, p. 99-112, 2018. DOI: 10.1016/j.matchar.2018.07.004

    Abstract: Correlation between corrosion resistance, anodic hydrogen evolution and microhardness in the friction stir weldment of AA2198-T851 alloy has been investigated. Different microscopy techniques, scanning vibrating electrode technique (SVET) and potentiodynamic polarization tests were employed in the investigation. Unlike other 3rd generation Al-Cu-Li alloys where the regions that are most susceptible to corrosion are always within the weld region, the results reveal that the parent material is the most susceptible in this case. There is a direct correlation between corrosion resistance, anodic hydrogen evolution and microhardness in the weldment, and the T1 phase is associated with the direct correlation.

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  • IPEN-DOC 25086

    AGUILA, A. del; SORRIBAS, M.; LYAMANI, H.; TITOS, G.; OLMO, F.J.; ARRUDA-MOREIRA, G.; YELA, M.; ALADOS-ARBOLEDAS, L.. Sources and physicochemical characteristics of submicron aerosols during three intensive campaigns in Granada (Spain). Atmospheric Research, v. 213, p. 398-410, 2018. DOI: 10.1016/j.atmosres.2018.06.004

    Abstract: Aerosol particles in the submicron range and their physicochemical characteristics were investigated for the first time in Granada, southeastern Iberian Peninsula, during three intensive campaigns. The physical and chemical characteristics were analysed during two spring campaigns and one autumn campaign. New particle formation (NPF) events were found to be more frequent in spring than in autumn. The mean duration, growth rates and maximum diameters had ranges of 5.3–13.2 h, 2.4–4.0 nm h−1 and 35–47 nm, respectively. In addition, one shrinkage event occurred and had a duration of 2.2 h and a shrinkage rate of −2.5 nm h−1. During a period of atmospheric stagnation conditions under the influence of mountain breezes, three consecutive NPF events occurred. The high frequency of the NPF events was attributed to higher temperature and radiation levels and lower relative humidity than during a previous day with similar stagnant conditions but no nucleation occurrence. According to correlation analysis, mineral components correlated with particle number in the Aitken mode, while metals and secondary inorganic aerosols correlated with particle number in the finer and larger fractions, respectively. Pollutants such as CO, NO2, NO and black carbon showed moderate and high correlations with particle number in the submicron fraction. To assess the impact of the particle number contribution according to sources, a new approach was introduced using black carbon concentrations, resulting in four major contributors: urban background, traffic, NPF and biomass burning. The proposed approach was validated by means of different models based on the aerosol spectral dependencies and chemical compositions that classify aerosol populations. Both the models and the proposed approach identified biomass burning and fossil fuel particles during the same periods, and the results showed good agreement. The proposed approach can guide future studies attempting to account for submicron particle contributions in other urban environments.

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  • IPEN-DOC 25084

    DARRIBA, GERMAN N.; MUNOZ, EMILIANO L.; CARBONARI, ARTUR W. ; RENTERIA, MARIO. Experimental TDPAC and theoretical DFT study of structural, electronic, and hyperfine properties in (111In → )111Cd-doped SnO2 semiconductor: Ab initio modeling of the electron-capture-decay after-effects phenomenon. Journal of Physical Chemistry C, v. 122, n. 30, p. 17423-17436, 2018. DOI: 10.1021/acs.jpcc.8b03724

    Abstract: In this paper we investigate the effect of Cd doping at ultralow concentrations in SnO2 both experimentally, by measuring the temperature dependence of the electric quadrupole hyperfine interactions with time-differential γ–γ perturbed angular correlation (TDPAC) spectroscopy using 111Cd as probe nuclei, and theoretically, by performing first-principles calculations based on the density functional theory. TDPAC spectra were successfully analyzed with a time-dependent on–off model for the perturbation factor. These results show combined dynamic plus static interactions whose electric-field-gradients were associated in this model to different stable electronic configurations close to the Cd atoms. The dynamic regime is then originated in fast fluctuations between these different electronic configurations. First-principles calculation results show that the Cd impurity introduces a double acceptor level in the top of the valence band of the doped semiconductor and produces isotropic outward relaxations of the nearest oxygen neighbors. The variation of the calculated electric-field gradient 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. The electron-capture decay of the parent 111In to 111Cd as well as the double acceptor character of the 111Cd impurity and the electric nature of the host are shown to contribute to the existence of these types of time-dependent hyperfine interactions.

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  • IPEN-DOC 25083

    COUTO, C.P. ; POLITANO, R. ; GOMES, M.P. ; COLOSIO, M.A.; ROSSI, J.L. . Diffusion analyses using GDOES technique of the 22MnB5 press hardened steel with Al-Si and Zn-Ni coatings. Materials Science Forum, v. 930, p. 472-477, 2018. DOI: 10.4028/www.scientific.net/MSF.930.472

    Abstract: The hot stamping process consists to heat the steel blank, at total austenitization temperatures and to transfer it into the press tooling for forming and fast cooling to fully martensitic transformation. This transference from furnace to press stage promotes some steel oxidation. The application of metallic coatings avoids this phenomenon. The Al-Si coating, a patented process, has been the most applied on steel. Hence, alternative coatings like Zn-Ni are under development. It is known that this furnace heating causes chemical elements diffusion that results in intermetallics formation. This study had the objective of analyze the diffusion profiles of chemical elements present in the substrate, 22MnB5 steel, and coatings of Al-Si and Zn-Ni, using glow-discharge optical emission spectroscopy - GDOES and to correlate the results with those obtained with energy dispersive X-ray spectroscopy - EDS. The results showed that for the Zn-Ni sample, the Zn and Fe profiles at the interfacial zone, are predominant; which justify the high proportion of ZnFe phases as showed using scanning electron microscopy - SEM images. For the Al-Si sample at the interfacial zone, the profile of Al and Fe varies simultaneously; besides that, silicon diffusion in the substrate is more effectively than the nickel diffusion. For this reason, it was possible to identify AlFeSi phase near to the steel substrate.

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  • IPEN-DOC 25082

    COSTA, ANDREA da; ZORGI, NAHIARA E.; NASCIMENTO, NANCI do ; GALISTEO JUNIOR, ANDRES J.; ANDRADE JUNIOR, HEITOR F. de. Gamma irradiation of Toxoplasma gondii protein extract improve immune response and protection in mice models. Biomedicine & Pharmacotherapy, v. 106, p. 599-604, 2018. DOI: 10.1016/j.biopha.2018.06.155

    Abstract: Gamma radiation induces protein changes that enhance immunogenicity for venoms, used in antivenin production. Coccidian parasites exposed to gamma radiation elicit immune response with protection in mice and man, but without studies on the effect of gamma radiation in soluble acellular extracts or isolated proteins. Toxoplasmosis is a highly prevalent coccidian disease with only one vaccine for veterinary use but with remaining tissue cysts. Total parasite extracts or recombinant proteins used as immunogen induce usually low protection. Here, we study gamma radiation effect on T. gondii extracts proteins (STAG) and its induced immunity in experimental mice models. By SDS-PAGE, protein degradation is seen at high radiation doses, but at ideal dose (1500 Gy), there are preservation of the antigenicity and immunogenicity, detected by specific antibody recognition or production after mice immunization. Immunization with STAG irradiated at 1500 Gy induced significant protection in mice immunized and challenged with distinct T. gondii strains. In their blood, higher levels of specific CD19+, CD3+CD4+ and CD3+CD8+ activated cells were found when compared to mice immunized with STAG. Irradiated T. gondii tachyzoites extracts induce immune response and protection in mice in addition, could be a feasible alternative for Toxoplasma vaccine.

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  • IPEN-DOC 25081

    CORDEIRO, GUILHERME L.; CAMARGO, ELAINE F. de; SANTOS, MONIQUE C.L. ; PEREIRA, CONRADO V.; USSUI, VALTER; LIMA, NELSON B. de; NETO, ALMIR O. ; LAZAR, DOLORES R.R.. Improved Pt/CeO2 electrocatalysts for ethanol electro-oxidation. International Journal of Electrochemical Science, v. 13, n. 7, p. 6388-6401, 2018. DOI: 10.20964/2018.07.58

    Abstract: A simple and low-cost approach for the preparation of wide-gap (Eg = 3.43 eV), fine cerium dioxide crystals (CeO2, d = 8.1 nm), was developed in order to support Pt nanoparticles as electrocatalysts for ethanol oxidation. Cerium oxide powders were prepared by precipitation from cerium chloride solution in ammonia medium and the influence of calcination temperature was evaluated. Platinum nanoparticles were incorporated by a wet chemical reduction of chloroplatinic acid with sodium borohydrate. Compared to a state-of-the-art Pt/C, the nanocomposite exhibited a much higher mass activity (2.5×) and significant anti-poisoning ability. The promotional effect of the CeO2 nanocrystals was discovered to be affected by heat treatment conditions. Compared to oven-dried samples, calcination allows to (i) an enhanced metal–support interaction between CeO2 and Pt and (ii) an enhancement of electron transportation to catalyst owing to the shrinkage of CeO2 bandgap, thereby promoting the oxidation of the strongly adsorbed CxHy. Therefore, the Pt/CeO2 nanocomposite appears to be a promising electrocatalyst for advanced energy conversion.

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  • IPEN-DOC 25080

    CONTURBIA, G.L.C.R.; DURAZZO, M. ; CARVALHO, E.F.U. de ; RIELLA, H.G. . Phase quantification in UAlx-Al dispersion targets for Mo-99 production. Journal of Nuclear Materials, v. 509, p. 465-477, 2018. DOI: 10.1016/j.jnucmat.2018.07.029

    Abstract: Uranium aluminide (UAlx) is a mixture of three distinct intermetallic compounds comprised of UAl2, UAl3 and UAl4, where the “x” is used to denote a mixture of those phases. Usually UAlx is formed during the target fabrication process by means of a solid state reaction between the uranium aluminide and aluminum. Quantitative techniques such as image analysis and X-ray diffraction using the Rietveld method were compared for their applicability in the determination of the UAl2, UAl3 and UAl4 concentrations, both in the UAl2 primary ingot and in the UAlx-Al dispersion. The UAlx composition was quantified in all stages of the target manufacturing. The image analysis method was shown to be useful for UAlx phase quantification in the primary UAl2 ingot, but was not applicable in the case of UAlx-Al dispersions. The X-ray diffraction method allowed the quantification of the existing UAlx phases in both the primary ingot and UAlx-Al dispersions. Possible sources of error are discussed. The method of quantification based on X-ray diffraction was shown to be appropriate to monitor the evolution of UAlx phases during the manufacturing process.

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  • IPEN-DOC 25079

    CHURA-CHAMBI, ROSA M. ; FRAGA, TATIANA R.; SILVA, LUDMILA B. da; YAMAMOTO, BRUNO B.; ISAAC, LOURDES; BARBOSA, ANGELA S.; MORGANTI, LIGIA . Leptospira interrogans thermolysin refolded at high pressure and alkaline pH displays proteolytic activity against complement C3. Biotechnology Reports, v. 19, n. e00266, p. 1-7, 2018. DOI: 10.1016/j.btre.2018.e00266

    Abstract: Enzymes from the thermolysin family are crucial factors in the pathogenesis of several diseases caused by bacteria and are potential targets for therapeutic interventions. Thermolysin encoded by the gene LIC13322 of the causative agent of leptospirosis, Leptospira interrogans, was shown to cleave proteins from the Complement System. However, the production of this recombinant protein using traditional refolding processes with high levels of denaturing reagents for thermolysin inclusion bodies (TL-IBs) solubilization results in poor recovery and low proteolytic activity probably due to improper refolding of the protein. Based on the assumption that leptospiral proteases play a crucial role during infection, the aim of this work was to obtain a functional recombinant thermolysin for future studies on the role of these metalloproteases on leptospiral infection. The association of high hydrostatic pressure (HHP) and alkaline pH was utilized for thermolysin refolding. Incubation of a suspension of TL-IBs at HHP and a pH of 11.0 is non-denaturing but effective for thermolysin solubilization. Soluble protein does not reaggregate by dialysis to pH 8.0. A volumetric yield of 46 mg thermolysin/L of bacterial culture and a yield of near 100% in relation to the total thermolysin present in TL-IBs were obtained. SEC-purified thermolysin suffers fragmentation, likely due to autoproteolysis and presents proteolytic activity against complement C3 α-chain, possibly by a generation of a C3b-like molecule. The proteolytic activity of thermolysin against C3 was time and dose-dependent. The experience gained in this study shall help to establish efficient HHP-based processes for refolding of bioactive proteins from IBs.

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  • IPEN-DOC 25078

    CASTRO, M.C. ; SILVA, N.F. ; CALDAS, L.V.E. . Testing an extrapolation chamber in computed tomography standard beams. Journal of Physics: Conference Series, v. 975, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012066

    Abstract: The computed tomography (CT) is responsible for the highest dose values to the patients. Therefore, the radiation doses in this procedure must be accurate. However, there is no primary standard system for this kind of radiation beam yet. In order to search for a CT primary standard, an extrapolation ionization chamber built at the Calibration Laboratory (LCI) of the Instituto de Pesquisas Energéticas e Nucleares (IPEN), was tested in this work. The results showed to be within the international recommended limits.

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  • IPEN-DOC 25077

    CASTRO, LILIANA ; MOREIRA, EDSON G. ; VASCONCELLOS, MARINA B.A. ; LANGE, CAMILA N. ; PEDRON, TATIANA; BATISTA, BRUNO L.. Stability assessment of a bovine kidney reference-material candidate. Journal of Radioanalytical and Nuclear Chemistry, v. 317, n. 2, p. 1133-1139, 2018. DOI: 10.1007/s10967-018-5928-8

    Abstract: Reference materials are used worldwide and necessary for quality control purposes during analytical determinations. The present study describes the stability evaluation of a bovine kidney reference-material candidate. An isochronous layout was performed, in which the flasks involved are exposed at different temperatures for different time periods and then are analyzed at the same time at the end of the study. The mass fractions of ten inorganic constituents were determined using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Statistical analysis, univariate and multivariate, showed no significant differences in composition between units exposed to the different temperatures and times. The reference material may be transported under normal transportation conditions and the certified values and uncertainties will continue to be valid for a period of 2 years.

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  • IPEN-DOC 25076

    CASTRO, MARCOS R. de ; MONTEIRO, WALDEMAR A. ; POLITANO, RODOLFO . Enhancements on strength of body structure due to bake hardening effect on hot stamping steel. International Journal of Advanced Manufacturing Technology, p. 1-12, 2018. DOI: 10.1007/s00170-018-2542-4

    Abstract: Body structure projects are designed to develop lightweight structures, which result in low fuel consumption and emissions for internal combustion engines and longer battery life in the case of electric vehicles. The structures need to be lightweight but also strong in order to provide maximum safety to the occupants. These premises have led to the development of special materials such as the hot stamping steels. The most used steel in this process, quenched 22MnB5, also exhibits the bake hardening effect: its yield stress increases after being exposed at temperatures close to 200 °C (typical heat treatment of paint lines in the automotive industry). The aim of this study was to verify the improvement in the mechanical strength of a body structure due to the bake hardening effect to which the hot-stamped steel componentswere submitted. Samples of annealed 22MnB5 steel were submitted to tensile and chemical analysis. A second group of the same steel was subjected to an additional heat treatment in a laboratory furnace simulating the heating that occurs in the body paint line. Subsequently, the same tests were performed with the samples from the first group. Tensile tests evidenced the increase of 6.5% in the yield stress of the samples that suffered the bake hardening effect. The stress-strain diagram curves were used as the input to the side crash simulation program. The simulations demonstrated that the body structure whose hot-stamped parts were subjected the bake hardening effect had a 2% reduction in side crash intrusion compared to body structure where the parts did not suffer this effect. In the case of the lateral protection bar test, the bake hardening effect provided a 5% increase in the maximum bending load.

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  • IPEN-DOC 25075

    CASTANHEIRA, BRUNA; TRIBONI, EDUARDO R.; ANDRADE, LUANA dos S.; TRINDADE, FABIANE de J.; OTUBO, LARISSA ; TEIXEIRA, ANTONIO C.S.C.; POLITI, MARIO J.; QUEIROZ, THIAGO B. de; BROCHSZTAIN, SERGIO. Synthesis of novel periodic mesoporous organosilicas containing 1,4,5,8-Naphthalenediimides within the pore walls and their reduction to generate wall-embedded free radicals. Langmuir, v. 34, n. 28, p. 8195-8204, 2018. DOI: 10.1021/acs.langmuir.8b00220

    Abstract: Novel periodic mesoporous organosilicas (PMOs) containing 1,4,5,8-Naphthalenediimide (NDI) chromophores as an integral part of the pore walls were synthesized in acidic conditions, in the presence of inorganic tetraethyl orthosilicate, using triblock copolymer surfactant Pluronic P-123 as a template. The NDI precursor, the bridged silsesquioxane N,N′-bis(3-triethoxysilylpropyl)-1,4,5,8-naphthalenediimide, was synthesized by reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride with excess 3-aminopropyltriethoxysilane. A series of samples containing up to 19% (weight %) of NDI were prepared (the materials were labeled PMONDIs). 13C and 29Si solid-state nuclear magnetic resonance revealed that the NDI moiety was intact in the PMONDIs and efficiently grafted to the silica network. Samples with up to 16% NDI load presented an ordered two-dimensional-hexagonal mesoscopic structure, according to small-angle X-ray scattering, transmission electron microscopy, and nitrogen adsorption isotherms. Fluorescence spectra of the PMONDIs showed excimer formation upon excitation, suggesting high flexibility of the organic moieties. Reduction of PMONDIs with aqueous sodium dithionite led to the formation of wall-embedded NDI anion radicals, as observed by the appearance of new visible/near-infrared absorption bands. The PMONDIs were also shown to be efficient photocatalysts in the degradation of sulfadiazine, an antibiotic selected here as a model pollutant, which is usually present in water bodies and wastewater.

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  • IPEN-DOC 25074

    CARDOSO, QUEZIA ; SILVA, FRANKS M.; VIEIRA, LIGIA S.; CASINI, JULIO C.S.; SAKATA, SOLANGE K. ; FARIA, RUBENS N. de . The production of reduced graphene oxide by a low-cost vacuum system for supercapacitor applications. Materials Science Forum, v. 930, p. 609-612, 2018. DOI: 10.4028/www.scientific.net/MSF.930.609

    Abstract: Graphene has attracted significant interest because of its excellent electrical properties. However, a practical method for producing graphene on a large scale is yet to be developed. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygencontaining groups and recovering the conjugated structure. GO can be produced using inexpensive graphite as the raw material via cost-effective chemical methods. High vacuum and temperature (10−7 mbar and 1100°C, respectively) conditions are well-known to enable the preparation of reduced powder at the laboratory scale. However, a large-scale high vacuum reduction system that can be routinely operated at 10−7 mbar requires considerable initial capital as well as substantial operational and maintenance costs. The current study aims at developing an inexpensive method for the large-scale reduction of graphene oxide. A stainless steel vessel was evacuated to backing-pump pressure (10−2 mbar) and used to process GO at a range of temperatures. The reduction of GO powder at low vacuum pressures was attempted and investigated by X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results of processing GO powder at various temperatures (200–1000°C) at relatively low pressures are reported. The microstructures of the processed materials were investigated using scanning electron microscopy and chemical microanalyses via energy dispersive X-ray analysis.

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  • IPEN-DOC 25073

    CONTATORI, CHESTER ; COUTO, ANTONIO A. ; VATAVUK, JAN; BORGES, ARNALDO A.C. ; LIMA, NELSON B. de ; BALDAN, RENATO. Effect of copper and magnesium on the microstructure of centrifugally cast Al-19%Si alloys. Materials Science Forum, v. 930, p. 484-488, 2018. DOI: 10.4028/www.scientific.net/MSF.930.484

    Abstract: Hypereutectic Al-Si alloys can be used in applications that require high wear resistance. Such wear resistance is achieved by the presence of hard primary silicon particles, allied to the formation of Mg2Si intermetallic phase when magnesium is added in this alloy. Centrifugal casting generates a gradient in the microstructure of hypereutectic Al-Si alloys that can favor such applications. Cylindrical components of Al-19%Si alloy containing added copper and magnesium contents were processed by centrifugal casting. The purpose of this study is to investigate the formation and segregation of particles of primary silicon (β) and Mg2Si in Al-19%Si alloy containing additions of copper and magnesium. Because the density of silicon (2.33 g/cm3) and Mg2Si (1.88 g/cm3) is lower than that of aluminum (2.67 g/cm3), centrifugal casting causes primary silicon (β) and Mg2Si particles to concentrate more at the outer wall of the centrifuged pipe. In this study, primary silicon (β) and Mg2Si particles were found to be retained at the outer wall of the pipe. It is believed that the rapid cooling of the molten metal in the region of contact with the mold, whose temperature is lower than that of the molten metal, allied to the centrifugal force, prevented the particles from migrating to the inner wall of the pipe. The microstructure shows a gradient in the distribution of these phases, enabling the production of a functionally graded material. The addition of copper and magnesium leads to the formation of Mg2Si and Al5Cu2Mg8Si6 phases, reducing the amount of primary β phase (Si) particles. In all the evaluated conditions, a tendency is also observed for a gradual increase in the segregation of silicon towards the inner wall along the entire length of the centrifuged pipe.

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  • IPEN-DOC 25072

    CAMPOS, FABIO E. de ; PERINI, EFRAIN A. ; ZAPPAROLI JUNIOR, CARLOS L. ; CALVO, WILSON A.P. ; STAROVOITOVA, VALERIIA N.. Main steps for radiopharmaceuticals hot cells validation in accordance with GMP requirements: methodology and practical guide. Journal of Environmental Science and Engineering A, v. 7, p. 132-139, 2018. DOI: 10.17265/2162-5298/2018.03.004

    Abstract: The worldwide GMP (Good Manufacturing Practices) guidelines issued for injectable pharmaceuticals globally agree that the vials filling operation must be performed under air cleanliness Grade A. The air cleanliness classifications adopted by the WHO (World Health Organization) define the particle diameter size, the sampling occupancy state and the limit concentration of viable particles. To reach conformity regarding the microbial limits foreseen at the GMP guidelines, a microbiological monitoring program must be stablished for selected sampling points such as active air sampling, passive air sampling (settle plate method), surfaces sampling (contact method), personnel sampling (gloves and clothes), compressed gas, materials and equipment that may interfere and compromise the product microbiological quality. The key elements for a GMP certification are directly related to a qualification and validation program for radiopharmaceutical manufacturers that must be clearly defined and documented by a validation master plan, foreseen by the manufactures Quality Assurance office. This study describes each qualification step and test for DQ (Design Qualification), IQ (Installation Qualification), OQ (Operation Qualification) and PQ (Performance Qualification) that must be carried out and carefully planned when it comes to hot cells and isolator systems in accordance with the GMP requirements foreseen by international regulatory and supervisory bodies.

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  • IPEN-DOC 25071

    BUENO, R.C.; MASOTTI, P.H.F. ; JUSTO, J.F.; ANDRADE, D.A. ; ROCHA, M.S. ; TORRES, W.M. ; MESQUITA, R.N. de . Two-phase flow bubble detection method applied to natural circulation system using fuzzy image processing. Nuclear Engineering and Design, v. 335, p. 255-264, 2018. DOI: 10.1016/j.nucengdes.2018.05.026

    Abstract: Natural circulation cooling systems are currently used in new nuclear reactors. Over the last decades, research in these systems has focused in the study of flow and heat transfer parameters. A particular area of interest is the estimation of two-phase flow parameters by image processing and pattern recognition using intelligent processing. Several methods have been proposed to identify objects of interest in bubbly two-phase images. Edge detection is an important task to estimate flow parameters, in which the bubbles are segmented to obtain several features, such as void fraction, area, and diameter. However, current methods face difficulties in determining those parameters in high bubble-density two-phase flow images. Here, a new edge detection method is proposed to segment bubbles in natural circulation instability images. The new method (Fuzzy Contrast Standard Deviation – FUZCON) uses Fuzzy Logic and image standard deviation estimates of locally measured contrast levels. Images were obtained through an experimental circuit made of glass, which enables imaging flow patterns of natural circulation cycles at ambient pressure. The results indicated important improvements on edge detection efficiency for high void fraction estimation on high-density two-phase flow bubble images, when compared to classical detectors, without the need to use smoothing algorithms or human intervention.

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  • IPEN-DOC 25070

    BARABAS, ROBERTA de C. ; LIMA, ANA C. de S. ; SABUNDJIAN, GAIANE . A neuroscience-based methodology to identify the implicit associations of brazilian science teachers towards nuclear technology. International Journal of Development Research, v. 8, n. 6, p. 20904-20909, 2018.

    Abstract: Science, technology, and innovation play an essential role in helping countries increase the quality of life they offer their citizens. Since the discovery of nuclear fission in the 30s, the peaceful applications of nuclear technology have benefited several fields. Improved crops, preservation of food, health, environment protection and a stable supply of energy can be cited as contributions of nuclear technology for global wellbeing. Despite all benefits that result from the peaceful uses of nuclear technology, it is still addressed with prejudice. Prejudices may be explicit (conscious) or implicit (unconscious). Either explicit or implicit, prejudices interfere with individuals’ attitudes. This paper aims to assess the implicit associations of Brazilian science teachers towards nuclear technology by administering the Implicit Association Test (IAT). Identifying their implicit associations will contribute for the understanding of prejudices that may interfere with their teaching. A pretest with nuclear specialists was administered to check the consistency of the IAT. Subsequently, it was administered to the science teachers. The results of the IAT demonstrated more positive associations towards oil. The next step consists of proposing a methodology to change implicit associations of Brazilian science teachers towards nuclear technology.

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  • IPEN-DOC 25069

    BORTOLETTO, DAIANA R.; LIMA, CASSIO A. ; ZEZELL, DENISE ; SATO, ERIKA T.; MARTINHO, H.. Vibrational spectra calculation of squamous cell carcinoma in the amide band region. Vibrational Spectroscopy, v. 97, p. 135-139, 2018. DOI: 10.1016/j.vibspec.2018.06.007

    Abstract: Alterations in the amide (1500–1700 cm−1) spectral region probed by Fourier-transform infrared spectroscopy (FTIR) have been reported comparing tumor and normal tissues. Usually, bands in this range are assigned to the so-called Amide I, II, and III vibrations which provide pieces of information concerning peptide bonds and secondary structure (α-helix, β-sheet) of proteins. Proteins folding changes due to tumoral process are usually considered to qualitatively explain the observed differences between tumor and normal tissues. In this paper, the observed changes in the FTIR spectra of squamous cell carcinoma compared to normal tissues were analyzed by First-Principles Density Functional Theory vibrational calculations. Computational models for skin and prototype β-sheet model were employed. Our findings shown that predominates conjugated Amide I + Amide II, Amide V, methylene torsions, and ring side chains torsions and swings vibrations in this region. We also notice the lack of evidence concerning changes in the secondary structure of the β-sheet peptidic model to explain the spectral differences. In fact, we concluded that the proline amino acid has the main rule to explain the data in this region being it responsible for the strong coupling between vibrations instead of water.

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  • IPEN-DOC 25068

    BORRELY, S.I. ; GARCIA, V.S.G. ; BORRELY, T.; FAVARO, D.I.T. . Metals, trace elements and ecotoxicity in sediments of the Cubatão River, Brazil. Ecotoxicology and Environmental Contamination, v. 13, n. 2, p. 49-61, 2018. DOI: 10.5132/eec.2018.02.07

    Abstract: The Cubatão River is one of the most important waterways of the coast of São Paulo. The continuous discharge of domestic and industrial effluents into the river and its tributaries resulted in loss of water quality across the system. Industrial and domestic landfills are also located around the studied area. The purpose of this study was to assess two aspects of sediments from the river and two of its tributaries (Perequê and Pilões Rivers): presence of trace elements and toxic metals, and ecotoxicity. Four sampling surveys were conducted from 2010 to 2011 on six different sites (here named P0, P2, P4, P5, P7 and P8). Ecotoxicity was assessed by exposing Hyalella azteca to the collected sediments. Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (GF AAS and CV AAS) techniques were applied for measuring concentration of metals and trace elements. The latter enabled quantification of Cd, Pb and Hg, while the former enabled quantification of a wide range of metals and trace elements. As, Cr and Zn concentrations obtained by INAA as well as AAS results were compared to threshold effect levels (TEL) and probable effect levels (PEL), the sediment quality guidelines proposed by the Canadian Council of Ministers of the Environment (CCME) for evaluating the potential effects on aquatic organisms. Cd and Hg values did not exceed TEL at the most of samples. Pb exceeded TEL at only one site campaign. As, Cr and Zn values exceeded TEL in most of sampling sites, with P2 and P4 showing the highest concentrations. Enrichment Factor (EF) and Geoaccumulation Index (IGeo) were calculated for the elements determined by INAA using North American Shale Composite (NASC) and regional background values. In short, As, Br, Cr, Hf, Pb, Sb and Zn were the elements found in concerning amounts, especially As, Br, Cr and Zn. Toxicity results revealed toxic effects on sediments from P2 and P5 (mortality > 50%). Body size analysis demonstrated negative effects at P4 (length smaller than 2,500.00 μm). Data crossing analyses indicate As and Br as main possible contributors to high toxicity levels.

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  • IPEN-DOC 25067

    BORGES, EDUARDO M. ; SABUNDJIAN, GAIANE ; CONTI, THADEU das N. ; BRAZ FILHO, FRANCISCO A.; GUIMARAES, LAMARTINE N.F.. Simulação de um SBLOCA em Angra 2 com o RELAP5 / RELAP5 simulation of the SBLOCA in Angra 2. Ciência, Tecnologia & Ambiente, v. 7, n. 1, 2018. DOI: 10.4322/2359-6643.07102

    Abstract: O objetivo deste trabalho foi simular e avaliar o acidente básico de projeto de perda de refrigerante por pequena ruptura de 50 cm2 na perna fria do circuito primário da usina nuclear Angra 2. Nesta simulação, verificou-se que as lógicas de atuação do Sistema de Proteção do Reator (SPR) e do Sistema de Resfriamento de Emergência do Núcleo (SREN) de Angra 2 utilizadas nesta simulação funcionaram corretamente, mantendo a integridade do núcleo com temperaturas aceitáveis durante todo o evento. Os resultados obtidos foram satisfatórios quando comparados com os apresentados pelo Relatório Final de Análise de Segurança de Angra 2 (FSAR/A2).

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  • IPEN-DOC 25066

    BORGES, CARLA R.; SAMAD, RICARDO E. ; GONCALVES, KARINA de O.; VIEIRA, DANIEL P. ; COURROL, LILIA C.. Interaction between protoporphyrin IX and tryptophan silver nanoparticles. Journal of Nanoparticle Research, v. 20, n. 6, 2018. DOI: 10.1007/s11051-018-4269-4

    Abstract: Silver nanoparticles (AgNPs) have been intensively studied for several purposes including therapeutic applications in cancer. When prepared with tryptophan and photoreduction, silver nanoparticles (TrpAgNPs) become an alternative to conventional anticancer drugs. In this study, the anticancer activity of synthesized TrpAgNPs against MCF-7 breast cancer cells was evaluated, and the inhibitory concentration (IC50) was found to be ~3.4 mg/mL. Since the protoporphyrin IX (PPIX) concentrations in tumor cells are elevate compared to normal cells, the PPIX-TrpAgNP interaction was studied to investigate if it could contribute for cell apoptosis. The investigation was performed using PPIX solution (0.9 μg/mL) with different TrpAgNP concentrations (from 0 to 13 mg/mL). PPIX was characterized by UV-Vis spectroscopy, steady-state and time-resolved fluorescence spectroscopy. The results have shown that the presence of spherical TrpAgNps with 16-nm diameter quench the PPIX fluorescence intensity. This quenching is strongly dependent on the concentration of the TrpAgNPs, and it is caused by a combination of a static and a dynamic process. The chemical binding leads to oxidation of tryptophan and formation of kynurenine, observed in the emission spectra around 470 nm. The strong reduction of the PPIX fluorescence decay lifetime with nanoparticle increasing concentration confirms the quenching processes due to charge transfer from the excited PPIX states to the resonant silver states. The present study confirms the anticancer activity of TrpAgNPs on the human breast cancer cell line (MCF-7) in vitro and indicates that PPIX-AgNP interaction could contribute with MCF-7 apoptosis.

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  • IPEN-DOC 25047

    VEIGA, MARCELLO M.; PASCHOAL, JOSE O.A. . Panorama do setor de materiais e suas relações com a mineração: uma contribuição para a implementação de linhas de P&D. Rio de Janeiro: CETEM/CNPq, 1991. 126 p. (Estudos e Documentos, 16).

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  • IPEN-DOC 25065

    BORGES, ARNALDO A.C. ; ARAUJO, MAYARA C. de ; COUTO, ANTONIO A. ; LIMA, NELSON B. de ; CONTATORI, CHESTER . Evaluation of the residual stress and microstructure of extruded and shot peened aluminum alloy 6082. Materials Science Forum, v. 930, p. 507-512, 2018. DOI: 10.4028/www.scientific.net/MSF.930.507

    Abstract: Aluminum-magnesium-silicon alloys have been widely used as extruded products due to its mechanical strength and high ductility. The effects induced by shot peening has been extensively used in materials that have potential for structural applications. In this context, the purpose of this study was to evaluate the residual stress induced by shot peening of extruded aluminum alloy 6082. Initially, the effect of heat treatments such as solution treatment and ageing of this alloy was studied. The residual stress measurements were carried out using x-ray diffraction. The microstructure of the alloy was studied by optical microscopy. The crystallographic texture was determined using x-ray diffraction and back-scattered electron diffraction. The heat treatment sequence that resulted in the highest hardness of Al alloy 6082 was solution treatment at 560ºC for 30 min, followed by ageing at 185ºC for 5 h. The residual stress in compression of the extruded alloy’s surface increased by 87.38%, from -66.6 to -124.8 MPa, caused by shot peening. The residual stress profile indicated an increase in its value up to a depth of 86 μm, beyond which the values obtained were unreliable. The extruded section revealed accentuated crystallographic texture in the (111) plane parallel to the cross-section and in the (200) and (220) planes oriented preferentially in the longitudinal direction to extrusion and perpendicular to the (111) plane.

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  • IPEN-DOC 25064

    BORDON, ISABELLA C.; EMERENCIANO, ANDREWS K.; MELO, JULIA R.C.; SILVA, JOSE R.M.C. da; FAVARO, DEBORAH I.T. ; GUSSO-CHOUERI, PALOMA K.; CAMPOS, BRUNO G. de; ABESSA, DENIS M. de S.. Implications on the Pb bioaccumulation and metallothionein levels due to dietary and waterborne exposures: the Callinectes danae case. Ecotoxicology and Environmental Safety, v. 162, p. 415-422, 2018. DOI: 10.1016/j.ecoenv.2018.07.014

    Abstract: This study aimed to assess the bioaccumulation of Pb and induction of metallothionein-like proteins (MT) in Callinectes danae through single and combined dietary and waterborne exposures. Male C. danae individuals were collected in the south area of the Cananéia-Iguape-Peruíbe Protected Area (APA-CIP), in São Paulo State, Brazil. After an acclimatization period, exposure assays were performed during 7 and 14 days, at two Pb concentrations (0.5 e 2.0 µg/g) in 4 treatments: 1) control; 2) contaminated water only; 3) contaminated food only; 4) contaminated water and food. The results indicate that C. danae is highly tolerant to Pb exposure at the evaluated concentrations. In gills, Pb bioaccumulation is more dependent of water efflux and time of exposure (higher Pb values). However, pathways act simultaneously in the induction of MT expression in this tissue. The decreases in Pb accumulation in the combined treatments and MT increases after 14 days in gills suggests that these proteins play a detoxification function in the presence of Pb. In hepatopancreas, depending on the predominance of a certain pathway or combined pathways, accumulation occured at different times. For muscle tissue, bioaccumulation was observed due to contaminated water exposure, but not dietary exposure, probably because Pb concentrations were low.

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  • IPEN-DOC 25063

    BORBOREMA, SAMANTA E.T. ; OSSO JUNIOR, JOAO A. ; TEMPONE, ANDRE G.; ANDRADE JUNIOR, HEITOR F. de; NASCIMENTO, NANCI do . Pharmacokinetic of meglumine antimoniate encapsulated in phosphatidylserine-liposomes in mice model: a candidate formulation for visceral leishmaniasis. Biomedicine & Pharmacotherapy, v. 103, p. 1609-1616, 2018. DOI: 10.1016/j.biopha.2018.05.004

    Abstract: Visceral leishmaniasis (VL) is a fatal parasitic disease caused by the protozoan Leishmania spp. Meglumine antimoniate (MA) is the main treatment and has demonstrated a promising efficacy in a VL-model when encapsulated into negatively charged liposomes. Considering the current concept for the evaluation of pharmacokinetic parameters at early phases of drug discovery, we developed a formulation of MA-encapsulated into phosphatidylserine liposomes (MA-LP) and analyzed the in vitro antileishmanial activity, physicochemical properties, and pharmacokinetic profile in a mice model. The liposomal formulation had an internal mean diameter of 114 nm and a high stability in plasma. MA-LP was 23-fold more in vitro effective against Leishmania infantum-infected macrophages than the free drug, with a selectivity index higher than 220. The pharmacokinetic studies demonstrated that the liposomes increased the uptake of the drug by the liver and spleen and promoted sustained levels. MA-LP was first eliminated through renal excretion, followed by biliary excretion. In the blood, MA-LP followed a biexponential open model. This work emphasizes the importance of liposomes as potential drug delivery systems for visceral leishmaniasis.

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  • IPEN-DOC 25062

    BEZERRA, S.J.C.; TREVISAN, L.R.; VIANA, I.E.L.; LOPES, R.M.; PEREIRA, D.L. ; ARANHA, A.C.C.; SCARAMUCCI, TAIS. Er,Cr:YSGG laser associated with acidulated phosphate fluoride gel (1.23% F) for prevention and control of dentin erosion progression. Lasers in Medical Science, p. 1-7, 2018. DOI: 10.1007/s10103-018-2609-3

    Abstract: To evaluate the effect of Er,Cr:YSGG laser, associated with fluoride application, on the prevention/control of dentin erosion. Dentin slabs were embedded in acrylic resin, flattened, and polished. Half of the specimens were previously eroded (10 min immersion in 1% citric acid solution) and half were kept sound. The specimens (n = 10 each substrate) were randomly allocated into the experimental groups, according to the following treatments: control (no treatment); APF gel (1.23% F, 1 min); Er,Cr:YSGG laser irradiation (P1: 0.25W, 20 Hz, 2.8 J/cm2, tip S75, beam diameter of 750 μm, 1mmaway fromthe surface); Er,Cr:YSGG laser irradiation (P2: 0.50W, 20 Hz, 5.7 J/cm2, tip S75, beam diameter of 750 μm, 1 mm away from the surface); APF gel + Er,Cr:YSGG laser P1 and; APF gel + Er,Cr:YSGG laser P2. Afterwards, the specimens underwent an erosion-remineralization cycling, consisting of a 5-min immersion into 0.3% citric acid, followed by 60-min exposure to artificial saliva. This procedure was repeated 4×/day, for 5 days. Surface loss (SL, in μm) was determined by optical profilometry. Specimens from each group were analyzed by environmental scanning electron microscopy (n = 3). Data were statistically analyzed (α = 0.05). For the eroded specimens, APF gel presented the lowest SL, being different from the control. For the sound specimens, none of the groups differed from the control, except for Er,Cr:YSGG laser P2, which presented the highest SL.When substrates were compared, only the eroded specimens of the control and APF + Er,Cr:YSGG laser P1 Groups showed higher SL. Selective structure removal was observed for the laser-treated groups. None of the Er,Cr:YSGG laser parameters were effective in the prevention/control dentin erosion. The laser was also unable to enhance the protection of fluoride against dentin erosion.

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  • IPEN-DOC 25061

    BETINI, EVANDRO G. ; GOMES, MAURILIO P. ; MUCSI, CRISTIANO S. ; LUZ, TEMISTOCLES de S.; ORLANDO, MARCOS T.D.; ROSSI, JESUALDO L. . Study of the thermal diffusivity variation in thin duplex steel plates welded by GTAW process. Materials Science Forum, v. 930, p. 460-465, 2018. DOI: 10.4028/www.scientific.net/MSF.930.460

    Abstract: This study describes the thermal diffusivity of thin duplex steel plates in the thickness direction measured using the laser-flash method after welding. The work reports the experimental efforts in recording temperature profiles of the grade UNS S32304 duplex steel during autogenous welding. The butt weld autogenous joints were carried out by the GTAW (gas tungsten arc welding) process with either argon or argon - 2% nitrogen atmospheres. The amount of nitrogen in the heat affected regions, after welding, was measured and correlated with the variation of the thermal diffusivity of the studied material. The temperature profiles were obtained using k-type thermocouples connected to a digital data acquisition system. Different thermal cycles and thermal diffusivity values were observed in the heat-affected zone (HAZ) for both samples. In the solidified zone (SZ) was observed similar increase of the thermal diffusivity values for the plates welded with pure argon and argon plus nitrogen atmosphere.

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  • IPEN-DOC 25060

    BERTOLETE, M.; BARBOSA, P.A.; MACHADO, A.R.; SAMAD, R.E. ; VIEIRA JUNIOR, N.D. ; VILAR, R.; ROSSI, W. de . Effects of texturing the rake surfaces of cemented tungsten carbide tools by ultrashort laser pulses in machining of martensitic stainless steel. International Journal of Advanced Manufacturing Technology, v. 98, n. 9-12, p. 2653-2664, 2018. DOI: 10.1007/s00170-018-2407-x

    Abstract: The present study investigates the effect of texturing the rake face of uncoated cemented tungsten carbide tools by ultrashort laser pulses for tribological improvement. In this sense, four parallel micro-groove texturing patterns were created on the rake face of the cutting tools, beginning at a variable distance from the cutting edge. The pitch between grooves was also varied. Friction force, machining force, chip features, and surface roughness were evaluated from semi-orthogonal dry turning in the reference (nontextured) and textured tools. The results showed friction force reduction by nearly 40%; chip deformation decrease around 21%; machining force reduction by 20%; and surface roughness by 46 and 28% for Ra and Rz, respectively, for the best texturing pattern.

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  • IPEN-DOC 25053

    BELLEZZO, MURILLO ; FONSECA, GABRIEL P.; VERRIJSSEN, AN-SOFIE; VONCKEN, ROBERT; BOSCH, MICHIEL R.V. den; YORIYAZ, HELIO ; RENIERS, BRIGITTE; BERBEE, MAAIKE; LIMBERGEN, EVERT J.V.; VERHAEGEN, FRANK. A novel rectal applicator for contact radiotherapy with HDR 192Ir sources. Brachytherapy, v. 17, n. 6, p. 1037-1044, 2018. DOI: 10.1016/j.brachy.2018.07.012

    Abstract: PURPOSE: Dose escalation to rectal tumors leads to higher complete response rates and may thereby enable omission of surgery. Important advantages of endoluminal boosting techniques include the possibility to apply a more selective/localized boost than using external beam radiotherapy. A novel brachytherapy (BT) rectal applicator with lateral shielding was designed to be used with a rectoscope for eye-guided positioning to deliver a dose distribution similar to the one of contact x-ray radiotherapy devices, using commonly available high-dose-rate 192Ir BT sources. METHODS AND MATERIALS: A cylindrical multichannel BT applicator with lateral shielding was designed by Monte Carlo modeling, validated experimentally with film dosimetry and compared with results found in the literature for the Papillon 50 (P50) contact x-ray radiotherapy device regarding rectoscope dimensions, radiation beam shape, dose fall-off, and treatment time. RESULTS: The multichannel applicator designed is able to deliver 30 Gy under 13 min with a 20350 U (5 Ci) source. The use of multiple channels and lateral shielding provide a uniform circular treatment surface with 22 mm in diameter. The resulting dose fall-off is slightly steeper (maximum difference of 5%) than the one generated by the P50 device with the 22 mm applicator. CONCLUSIONS: A novel multichannel rectal applicator for contact radiotherapy with high-doserate 192Ir sources that can be integrated with commercially available treatment planning systems was designed to produce a dose distribution similar to the one obtained by the P50 device.

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  • IPEN-DOC 25057

    BARDELLA, FERNANDO ; MORAES, RAFAEL C. de; SARINGELOS, THANOS; KARATZAFERIS, ALEXANDROS; RODRIGUES, ANDRE M. ; SILVA, ANDRE G. da ; LEAL NETO, RICARDO M. . Architecting 3D interactive educational applications for the web: the case study of crystalwalk. Multimodal Technologies and Interaction, v. 2, n. 3, p. 1-12, 2018. DOI: 10.3390/mti2030056

    Abstract: This paper describes the technical development of CrystalWalk, a crystal editor and visualization software designed for teaching materials science and engineering aiming to provide an accessible and interactive platform to students, professors and researchers. Justified by the lack of proper didactic tools, an evaluation of the existing crystallographic software has further shown opportunities for the development of a new software, more focused on the educational approach. CrystalWalk’s was guided by principles of free software, accessibility and democratization of knowledge, which was reflected in the application’s architecture strategy and the adoption of state-of-the-art technologies for the development of interactive web applications, such as HTML5/WebGL, service-oriented architecture (SOA) and responsive, resilient and elastic distributed systems. CrystalWalk’s architecture was successful in supporting the implementation of all specified software requirements proposed by state-of-the-art research and deemed to exert a positive impact in building accessible 3D interactive educational applications for the web.

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  • IPEN-DOC 25059

    AZEVEDO, MARIANGELA de B.M. de ; MELO, VITOR H.S. de ; SOARES, CARLOS R.J. ; MIYAMOTO, DOUGLAS M. ; KATAYAMA, RICARDO A. ; SQUAIR, PETERSON L. ; BARROS, CAIO H.N.; TASIC, LJUBICA. Development and characterization of polymeric microparticle of poly(D,L-lactic acid) loaded with holmium acetylacetonate. Journal of Microencapsulation: micro and nano carriers, v. 35, n. 3, p. 281-291, 2018. DOI: 10.1080/02652048.2018.1477843

    Abstract: Biodegradable polymers containing radioactive isotopes such as Holmium 166 (166Ho) have potential applications as beta particle emitters in tumour tissues. It is also a gamma ray emitter, allowing nuclear imaging of any tissue to be acquired. It is frequently used in the form of complexes such as holmium acetylacetonate (HoAcAc), which may cause damages in tissues next to the targets cancer cells, as it is difficult to control its linkage or healthy tissues radiotherapy effects. Poly(d,l-lactic acid), PDLLA, was used to encapsulate holmium acetylacetonate (HoAcAc) using an emulsion solvent extraction/evaporation technique. Microspheres with sizes between 20-53 µm were extensively characterised. HoAcAc release from the microspheres was assessed through studies using Inductively Coupled Plasma – Optical Emission Spectroscopy, and the microspheres showed no holmium leakage after a period of 10 half-lives and following gamma irradiation. Thus, HoAcAc loaded microspheres are here presented as a potential system for brachytherapy and imaging purposes.

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  • IPEN-DOC 25058

    ARANHA, L.C. ; MUCSI, C.S. ; CEONI, F.C. ; ALENCAR, M.C. ; ROSSI, J.L. . Development of a microtorquemeter for the evaluation of the implant abutment interface behavior. Materials Science Forum, v. 930, p. 520-525, 2018. DOI: 10.4028/www.scientific.net/MSF.930.520

    Abstract: This paper presents the initial developments of a prototype device intended to perform measurements of the fastening torque in the range bellow 1 N.m – hereby denominated microtorque. The device is intended to yield data for analysis of in vitro torquing and detorquing experiments, for fixation and removing of abutments in dental implants and implants in artificial bones. The analysis of the data acquired allowed the authors to observe characteristic fingerprints or signal signatures associated to the type of abutment or implant under experimentation as well as of the mechanical prototype characteristics. In this paper, two different systems of abutment and implant were analyzed. The correlation between the phenomena associated to the signal fingerprints indicate that the developed measurement protocol may be extended to other implant / abutment systems. The authors suggest that the insertion and removal torque curves evaluated in this study would facilitated the correlation between the abutments stability in actual patients and the dynamical behavior under masticatory function.

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  • IPEN-DOC 25056

    ANTUNES, RENATO A.; OLIVEIRA, MARA C.L. de; FERRAZ, LUCAS C. de C.; GONCALES, LETICIA dos R.; CORREA, OLANDIR V. . Study of the correlation between microstructure and corrosion resistance of the AZ91D magnesium alloy. Materials Science Forum, v. 930, p. 405-410, 2018. DOI: 10.4028/www.scientific.net/MSF.930.405

    Abstract: The aim of the present work was to study the influence of beta phase precipitates content and distribution on the corrosion behavior of the AZ91D magnesium alloy, using samples subjected to solution annealing and aging. The morphology of the beta phase was observed using optical microscopy and scanning electron microscopy. The volume fraction of each phase was also determined. Potentiodynamic polarization tests and immersion tests were carried out, indicating an increase of the corrosion resistance with the volume fraction of the beta phase and its distribution on the grain boundaries of the alpha-phase. Solution annealed samples were more susceptible to corrosion.

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  • IPEN-DOC 25055

    ANGELOCCI, LUCAS V. ; YORIYAZ, HELIO . Mesh-based human eye anatomy for Monte Carlo dose calculation. New Frontiers in Ophthalmology, v. 4, n. 4, p. 1-5, 2018. DOI: 10.15761/NFO.1000209

    Abstract: Purpose: The purpose of this work is to explore the capability of the MCNP6 unstructured mesh geometry resources to create an eye and tumor anatomic model for ophthalmic brachytherapy dosimetry. Methods: Abaqus/CAE software was utilized to construct three anatomic eye models using first order tetrahedral mesh elements: a model with a 2 cm in diameter deep tumor; a model with a 1.2 cm in diameter deep tumor; and a model with a 1.2 cm superficial tumor. 2 cm and 1.2 cm COMS applicators fully loaded with Amersham 6711125I seeds were coupled to the eye models for dose calculation using the MCNP6 code. The dose values in the structures of the eye were compared to those obtained using analytical models. Results: Unstructured mesh model has small differences (maximum of 3.4%) in the mass values of the components of the eye comparing to those obtained in the analytical model. Excluding the optical nerve wall, all dose differences were beneath 4% for all structures. The overall dose in the eye agrees within 2% between different models. Conclusions: The feasibility of using unstructured mesh based geometries to model fine structures of the eye has been verified in this study. It was possible to create adequately the anatomic model of the human eye with reproducible dose values compared to reference values.

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  • IPEN-DOC 25054

    ALVIM, DEBORA S. ; GATTI, LUCIANA V. ; CORREA, SERGIO M.; CHIQUETTO, JULIO B.; SANTOS, GUACIARA M.; ROSSATTI, CARLOS de S.; PRETTO, ANGELICA ; ROZANTE, JOSE R.; FIGUEROA, SILVIO N.; PENDHARKAR, JAYANT; NOBRE, PAULO. Determining VOCs reactivity for ozone forming potential in the megacity of São Paulo. Aerosol and Air Quality Research, v. 18, n. 9, p. 2460-2474, 2018. DOI: 10.4209/aaqr.2017.10.0361

    Abstract: High ozone (O-3) concentrations are a major concern about air quality in the Sao Paulo Metropolitan Area (SPMA). During 2016, the 8-hour state standard of 140 mu g m(-3) was exceeded on 32 days, whereas the 1-hour national standard of 160 mu g m(-3) was exceeded on 76 days. Exposure to such unhealthy O-3 levels and other pollutants can lead to respiratory disease. The focus of this study is to determine the main O-3 precursor in terms of the volatile organic compounds (VOCs) in order to provide a scientific basis for controlling this pollutant. In this work, 66 samples of hydrocarbons, 62 of aldehydes and 42 of ethanol were taken during the period from September 2011 to August 2012 from 7:00 to 9:00 a.m. The OZIPR trajectory model and SAPRC atmospheric chemical mechanism were used to determine the major O-3 precursors. During the studied period, aldehydes represented 35.3% of the VOCs, followed by ethanol (22.6%), aromatic compounds (15.7%), alkanes (13.5%), ketones (6.8%), alkenes (6.0%) and alkadienes (less than 0.1%). Considering the concentration of VOCs and their typical reactivity, the simulation results showed that acetaldehyde contributed 61.2% of the O-3 formation. The total aldehydes contributed 74%, followed by aromatics (14.5%), alkenes (10.2%), alkanes (1.3%) and alkadienes (e.g., isoprene; 0.03%). Simulation results for the SPMA showed that the most effective alternative for limiting the O-3 levels was reducing the VOC emissions, mainly the aldehydes.

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  • IPEN-DOC 25052

    ALVARENGA, LETICIA H.; RIBEIRO, MARTHA S. ; KATO, ILKA T.; NUNEZ, SILVIA C.; PRATES, RENATO A.. Evaluation of red light scattering in gingival tissue – in vivo study. Photodiagnosis and Photodynamic Therapy, v. 23, p. 32-34, 2018. DOI: 10.1016/j.pdpdt.2018.05.016

    Abstract: Antimicrobial photodynamic therapy (aPDT) has been used to treat periodontal disease, thus the aim of this study was to investigate red light (ʎ = 660 nm) attenuation in gingival tissue. This clinical trial included 30 patients with chronic periodontitis; three incisors from each patient were selected for the experimental procedures. A laser source with a radiant power output of 100 mW was used. Two digital photographs were taken of each selected incisor (in frontal and occlusal position). The images were analyzed in the ImageJ program. The results demonstrated that at a 3 mm distance from the laser probe, there is an attenuation of light intensity of 50%, along frontal and occlusal views. Light attenuation in gingival tissue should be considered when setting optimal parameters for antimicrobial photodynamic therapy or photobiomodulation.

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  • IPEN-DOC 25051

    ALVARENGA, NUNO; TAIPINA, MAGDA ; RAPOSO, NELIA; DIAS, JOAO; CARVALHO, MARIA J.; AMARAL, OLGA; SANTOS, MARIA T.; SILVA, MARIA M.; LIDON, FERNANDO C.. Development of biscuits with green banana flour irradiated by Co-60: preservation in modified atmosphere packaging. Emirates Journal of Food and Agriculture, v. 30, n. 6, p. 496-502, 2018. DOI: 10.9755/ejfa.2018.v30.i6.1720

    Abstract: Banana it's one of the most consumed fruits in the world but 20% of the production is wasted, mostly due to post-harvest losses, or because it doesn't fit in consumers standards. Nonetheless, Green Banana Flour (GBF) can be an alternative to minimize these losses, further being a good source of nutrients, fiber, resistant starch and micronutrients. Considering the interesting possibilities of GBF utilization in the agrofood sector, the aims of this study, was the development of GBF cookies and preservation during three months in two different types of modified atmosphere. The experimental design considered GBF radiation with gamma radiation (1 kGy and 3 kGy), with additional packaging in modified atmosphere, using 100% CO2 or a gas mixture containing 2% O-2; 88% N-2 e 10% CO2. As a control, non-radiated GBF was used. In general, it was observed that samples submitted to 3 kGy radiation, had the best results. Besides, packaging with gases mixture showed higher efficiency for GBF cookies preservation, due to CO2.

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  • IPEN-DOC 25050

    ALMEIDA, MARIANA C. ; SAMPAIO, GENI R.; BASTOS, DEBORAH H.M.; VILLAVICENCIO, ANNA L.C.H. . Effect of gamma radiation processing on turmeric: antioxidant activity and curcumin content. Radiation Physics and Chemistry, v. 152, p. 12-16, 2018. DOI: 10.1016/j.radphyschem.2018.07.008

    Abstract: The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 5, 10, 15 and 20 kGy on turmeric (Curcuma longa Linn.). The quantification of phenolic compounds was performed by Folin-Ciocalteu method and assessing the potential of antioxidant activity by the free radical [2,2 difenil-1-pricril-hidrazil (DPPH•)] scavenging and by Rancimat® method. The curcumin quantification was performed by High Performance Liquid Chromatography. Compared to control, there were significant losses (p < 0,05) of total phenolic compounds in the samples irradiated with 15 kGy (p = 0001) and 20 kGy (p = 0001). Regardless the irradiation, there was no decrease in the ability to scavenge free radicals. The Antioxidant Activity Index (Rancimat® method) was significantly lower (p < 0,05) in 5 kGy (p < 0001) and 15 kGy (p = 0003) irradiated extracts and the curcumin quantification was significantly lower (p < 0,05) in 15 kGy irradiated extract (p < 0001). It is concluded that gamma radiation processing technology on turmeric can be viable. To maintain safety of antioxidant activity it should be applied doses up 10 kGy.

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  • IPEN-DOC 25049

    ALMEIDA, GISELE F.C. ; COUTO, ANTONIO A. ; REIS, DANIELI A.P.; MASSI, MARCOS; SILVA SOBRINHO, ARGEMIRO S. da; LIMA, NELSON B. de . Effect of plasma nitriding on the creep and tensile properties of the Ti-6Al-4V alloy. Metals, v. 8, n. 8, p. 1-15, 2018. DOI: 10.3390/met8080618

    Abstract: This work aimed to enhance the creep resistance of Ti-6Al-4V alloy treated by plasma nitriding. The nitriding was performed on specimens with aWidmanstätten microstructure for four hours at 690 C under a gas atmosphere containing Ar:N2:H2 (0.455:0.455:0.090). X-ray diffraction analysis showed that the "-Ti2N and -TiN formed on the nitrided sample, in addition to the -Ti and -Ti matrix phases. The layer thickness of this sample was about 1 m. Hot tensile tests were performed in the temperature range of 500 to 700 C on nitrided and non-nitrided samples, which indicated an increased strength of the nitrided samples. The same temperature range was used for the creep tests in a stress range of 125 to 319 MPa. The plasma-nitrided samples exhibited better creep resistance when compared to the untreated samples. This result was demonstrated by the decreased secondary creep rate and the increased final creep time. This improvement in the creep resistance appeared to be associated with the formation of the nitrided layer, which worked as a barrier to oxygen diffusion into the material and due to the formation of a surface residual compressive stress.

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  • IPEN-DOC 25048

    ALMEIDA, S.B. ; VILLANI, D. ; SAKURABA, R.K.; REZENDE, A.C.P.; CAMPOS, L.L. . Comparative study of the TL response of LiF:Mg,Ti and CaSO4:Dy in the clinical electron beams dosimetry applied to total skin irradiation (TSEB) treatments. Radiation Physics and Chemistry, v. XX, n. XX, p. XX-XX, 2018. DOI: 10.1016/j.radphyschem.2018.05.025

    Abstract: The commissioning and quality assurance The Total Skin Electron Beam (TSEB) irradiation treatment is based on the AAPM's report 23, which describes the six-dual-field (Standford) technique, and the Hospital Israelita Albert Einstein (HIAE) follows this recommended guidance. The Dosimetric Materials Laboratory of the Instituto de Pesquisas Energéticas e Nucleares (IPEN-LMD) has tradition in research related to thermoluminescent materials and its clinical applications. Thus, aiming to apply the LiF:Mg,Ti, the most common TLD material, and CaSO4:Dy + Teflon produced at IPEN as easy-to-use alternatives to electron beams dosimetry and its parameters applied to TSEB, this paper reports a comparative study of the TL responses of both materials to dose evaluation in TSEB treatments. The TL response of both materials was evaluated in several TSEB parameter tests such as clinical field homogeneity, Monitor Units (MU) calculation, absorbed doses over the reference line and throughout the surface of the skin in a treatment simulation using AldersonRando anthropomorphic phantom. Results show that the field homogeneity measurements remained within ± 8% acceptance limit from AAPM Report 23, little to no energy dependency over the range of 4 o 9 MeV electron beams and, for clinical measurements and MU calculations, both TLDs present compatible results and can be used as alternative tools in TSEB dosimetry.

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  • IPEN-DOC 25046

    AFFONSO, REGINA ; SOARES, CARLOS R. ; RIBELA, MARIA T. ; BARTOLINI, PAOLO . High production and optimization of the method for obtaining pure recombinant human prolactin. Protein Expression and Purification, v. 152, p. 131-136, 2018. DOI: 10.1016/j.pep.2018.07.015

    Abstract: Prolactin is a pituitary hormone that is involved diverse physiological functions, such as lactation, reproduction, metabolism, osmoregulation, immunoregulation, and behavior. Its level of glycosylation is low in vivo, which favors its expression in bacterial systems. In the present work recombinant human prolactin (rec-hPRL) was expressed from the p1813-hPRL vector in Escherichia coli strain in inclusion bodies with 530.67 mg of rec-hPRL per liter of induced bacterial culture. The solubilization and renaturation of rec-hPRL followed by two methods described in the literature for this protein: one with detergent and basic pH, and other urea and dialyses was done by studying. The protocol with detergent/basic pH was not successful, whereas protocol with urea/dialyses was obtained pure protein and this was optimized. Rec-hPRL was obtained in a soluble, pure and active form, when the sample was 8-fold concentrated in the solubilization phase, allowing 33% recovery, 3-fold more that the original method. The pure protein was obtained with 38.37 i. u./mg activity, which is three times greater than that of the PRL standard from the WHO. In conclusion, this work obtained the highest production of rechPRL, and concentrating the sample eight times in the solubilization stage was decisive for obtaining a highly concentrated, active protein for future work.

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  • IPEN-DOC 24395

    VELO, A.F. ; CARVALHO, D.V.S. ; HAMADA, M.M. . Liquid distribution and holdup in the random packed column. Flow Measurement and Instrumentation, v. 62, p. 176-185, 2018. DOI: 10.1016/j.flowmeasinst.2017.11.002

    Abstract: In the present work, a third-generation gamma transmission tomography system was used to evaluate the liquid distributions of a Raschig rings random packed column, at two different water flows: 2 and 6 l/min. For each water flow, the measurements were carried out at nine column heights. The liquid-gas holdup was determined by the reconstructed images. The distribution of the Raschig rings, as well as the position and the average accumulated amount of the water concentration among the Raschig rings were capable to be determined, even at low temporal resolution of the system of 8.8 h. The regions of accumulated water concentration were similar for the water flow velocities at 2 and 6 l/min. The average accumulated water concentration for 6 l/min was higher compared to 2 l/min. The spatial resolution of the tomography system determined by the modulation transfer function (MTF) analysis was of 1.45 mm.

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  • IPEN-DOC 24392

    HARAGUCHI, MARCIO I.; CALVO, WILSON A.P. ; KIM, HAE Y.. Tomographic 2-D gamma scanning for industrial process troubleshooting. Flow Measurement and Instrumentation, v. 62, p. 235-245, 2018. DOI: 10.1016/j.flowmeasinst.2017.09.004

    Abstract: Gamma scanning is a nuclear inspection technique widely used to troubleshoot industrial equipments in refineries and petrochemicals plants such as distillation columns and reactors. In this technique, a sealed radiation source and detector move along the equipment, and the intensity readouts generate the density profile of the equipment. Although many improvements have been introduced in recent years, the result of gamma scan still consists of a simple 1-D density plot. In this work, we present the tomographic gamma scanning that, using image reconstruction techniques, shows the result as a 2-D image of density distribution. Clearly, an image reveals more features of the equipment than a 1-D graph and many problems that could not be troubleshooted using the conventional technique can now be solved with this imaging technique. We use ART (Algebraic Reconstruction Technique) intercalated with total variation minimization filter. The use of total variation minimization leads to compressive sensing tomography, allowing to obtain good quality reconstruction from few irradiation data. We simulated the reconstruction of different density distributions. We applied the new technique to data obtained by irradiating with gamma rays phantoms that emulate industrial equipments. Finally, we present the result obtained by applying the innovative technique to real operating distillation column. It seems that the new technique has identified a problem in this equipment that is very difficult to detect using conventional gamma scan.

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  • IPEN-DOC 25045

    RODRIGUES, THENNER S. ; MOURA, ARTHUR B.L. de ; SILVA, FELIPE A. e ; CANDIDO, EDUARDO G. ; SILVA, ANDERSON G.M. da; OLIVEIRA, DANIELA C. de; QUIROZ, JHON; CAMARGO, PEDRO H.C.; BERGAMASCHI, VANDERLEI S. ; FERREIRA, JOAO C. ; LINARDI, MARCELO ; FONSECA, FABIO C. . Ni supported Ce0.9Sm0.1O2-δ nanowires: an efficient catalyst for ethanol steam reforming for hydrogen production. Fuel, v. 237, p. 1244-1253, 2019. DOI: 10.1016/j.fuel.2018.10.053

    Abstract: We reported herein the synthesis in high yields (> 97%) of Ce0.9Sm0.1O2-δ nanowires displaying well-defined shape, size, and composition by a simple, fast, and low-cost two-step hydrothermal method. The Ce0.9Sm0.1O2-δ nanowires synthesis was followed by the wet impregnation of Ni without the utilization of any stabilizing agent. The Ni/Ce0.9Sm0.1O2-δ nanowires showed higher surface area, high concentration of oxygen vacancies at surface, and finely dispersed Ni particles with significantly higher metallic surface area as compared with catalysts prepared from commercial materials with similar compositions. Such unique and improved properties are reflected on the catalytic performance of the Ni/Ce0.9Sm0.1O2-δ nanowires towards ethanol steam reforming. The nanowires exhibited high yields for hydrogen production (∼60% of selectivity) and an exceptional stability with no loss of activity after 192 h of reaction at 550 °C. The reported results provide insights and can inspire highyield production of nanostructured catalysts displaying controlled and superior properties that enable practical applications in heterogeneous catalysis.

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  • IPEN-DOC 25044

    MARTINS-JUNIOR, HELIO A. ; LEBRE, DANIEL T.; WANG, ALEXANDRE Y.; PIRES, MARIA A.F. ; BUSTILLOS, OSCAR V. . Residue analysis of glyphosate and Aminomethylphosphonic Acid (AMPA) in soybean using liquid chromatography coupled with Tandem Mass Spectrometry. In: NG, TZI B. (Ed.). Soybean - biochemistry, chemistry and physiology. Rijeka, Croatia: IntechOpen, 2011. p. 495-506, cap. 27. DOI: 10.5772/15817

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  • IPEN-DOC 25039

    ALVES, ELIANE G.; TOTA, JULIO; TURNIPSEED, ANDREW; GUENTHER, ALEX B.; VEGA BUSTILLOS, JOSE O.W. ; SANTANA, RAONI A.; CIRINO, GLAUBER G.; TAVARES, JULIA V.; LOPES, ALINE P.; NELSON, BRUCE W.; SOUZA, RODRIGO A. de; GU, DASA; STAVRAKOU, TRISSEVGENI; ADAMS, DAVID K.; WU, JIN; SALESKA, SCOTT; MANZI, ANTONIO O.. Leaf phenology as one important driver of seasonal changes in isoprene emissions in central Amazonia. Biogeosciences, v. 15, n. 13, p. 4019-4032, 2018. DOI: 10.5194/bg-15-4019-2018

    Abstract: Isoprene fluxes vary seasonally with changes in environmental factors (e.g., solar radiation and temperature) and biological factors (e.g., leaf phenology). However, our understanding of the seasonal patterns of isoprene fluxes and the associated mechanistic controls is still limited, especially in Amazonian evergreen forests. In this paper, we aim to connect intensive, field-based measurements of canopy isoprene flux over a central Amazonian evergreen forest site with meteorological observations and with tower-mounted camera leaf phenology to improve our understanding of patterns and causes of isoprene flux seasonality. Our results demonstrate that the highest isoprene emissions are observed during the dry and dry-to-wet transition seasons, whereas the lowest emissions were found during the wet-to-dry transition season. Our results also indicate that light and temperature cannot totally explain isoprene flux seasonality. Instead, the camera-derived leaf area index (LAI) of recently mature leaf age class (e.g., leaf ages of 3-5 months) exhibits the highest correlation with observed isoprene flux seasonality (R-2 = 0.59, p < 0.05). Attempting to better represent leaf phenology in the Model of Emissions of Gases and Aerosols from Nature (MEGAN 2.1), we improved the leaf age algorithm by utilizing results from the camera-derived leaf phenology that provided LAI categorized into three different leaf ages. The model results show that the observations of age-dependent isoprene emission capacity, in conjunction with camera-derived leaf age demography, significantly improved simulations in terms of seasonal variations in isoprene fluxes (R-2 = 0.52, p < 0.05). This study highlights the importance of accounting for differences in isoprene emission capacity across canopy leaf age classes and identifying forest adaptive mechanisms that underlie seasonal variation in isoprene emissions in Amazonia.

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  • IPEN-DOC 25038

    NATALE, LIVIA C.; RODRIGUES, MARCELA C.; ALANIA, YVETTE; CHIARI, MARINA D.S.; BOARO, LETICIA C.C.; COTRIM, MARYCEL ; VEGA, OSCAR ; BRAGA, ROBERTO R.. Mechanical characterization and ion release of bioactive dental composites containing calcium phosphate particles. Journal of the Mechanical Behavior of Biomedical Materials, v. 84, p. 161-167, 2018. DOI: 10.1016/j.jmbbm.2018.05.022

    Abstract: Objective: to verify the effect of the addition of dicalcium phosphate dihydrate (DCPD) particles functionalized with di- or triethylene glycol dimethacrylate (DEGDMA or TEGDMA) on the degree of conversion (DC), post-gel shrinkage (PS), mechanical properties, and ion release of experimental composites. Methods: Four composites were prepared containing a BisGMA/TEGDMA matrix and 60 vol% of fillers. The positive control contained only barium glass fillers, while in the other composites 15 vol% of the barium was replaced by DCPD. Besides the functionalized particles, non-functionalized DCPD was also tested. DC after 24 h (n=3) was determined by FTIR spectroscopy. The strain gage method was used to obtain PS 5 min after photoactivation (n=5). Flexural strength and modulus (n=10) were calculated based on the biaxial flexural test results, after specimen storage for 24 h or 60 days in water. The same storage times were used for fracture toughness testing (FT, n=10). Calcium and phosphate release up to 60 days was quantified by ICP-OES (n=3). Data were analyzed by ANOVA/Tukey test (alpha: 5%). Results: Composites containing functionalized DCPD presented higher DC than the control (p < 0.001). The material containing DEGDMA-functionalized particles showed higher PS than the other composites (p < 0.001). After 60 days, only the composite with DEGDMA-functionalized DCPD presented fracture strength similar to the control, while for flexural modulus only the composite with TEGDMA-functionalized particles was lower than the control (p < 0.001). FT of all composites containing DCPD was higher than the control after 60 days (p < 0.005). Calcium release was higher for the composite with non-functionalized DCPD at 15 days and no significant reductions were observed for composites with functionalized DCPD during the observation period (p < 0.001). For all the tested composites, phosphate release was higher at 15 days than in the subsequent periods, and no difference among them was recorded at 45 and 60 days (p < 0.001). Conclusions: DCPD functionalization affected all the studied variables. The composite with DEGDMA-functionalized particles was the only material with strength similar to the control after 60 days in water; however, it also presented the highest shrinkage. The presence of DCPD improved FT, regardless of functionalization. DCPD functionalization reduced ion release only during the first 15 days.

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  • IPEN-DOC 25037

    BUSTILLOS, OSCAR V. ; SASSINE, ANDRE. A magia da curva cicloide: braquistocrona e tautocrona. São Paulo: Scortecci, 2011. 256 p.

    Notas de conteúdo: Livro disponível somente na versão impressa. Consulte a biblioteca do IPEN.

    Abstract: O livro explora a curva cicloide, desde o gênesis até suas aplicações e também as consequências que acarretaram o estudo da curva cicloide. A obra apresenta os enredos históricos dos protagonistas que estudaram a curva cicloide, mostrando por qual motivo ela é chamada de Helena dos geômetras. Entre os protagonistas estão os irmãos Bernoulli, Newton, Leibniz, Pascal, Roberval, Galileu e outros.

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  • IPEN-DOC 25043

    BITELLI, ULYSSES D. . Comissionamento : calibração da potência do reator IPEN/MB-01 pela Técnica de Análise por Ativação Neutrônica. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-RMB-005-00-RELT-084-00). Restrito.

    Título do projeto: Reator Multipropósito Brasileiro (RMB)

    Abstract: Este relatório apresenta o procedimento de comissionamento para a calibração da potência do reator IPEN/MB-01, utilizando a técnica de análise por ativação neutrônica, através da irradiação de folhas de ouro com e sem cobertura (nuas) de cádmio. [1,2,3], posicionadas no interior do núcleo do reator IPEN/MB-01. O valor médio do fluxo de nêutrons e por conseqüência de potência obtido é correlacionado com o valor médio de corrente dos canais nucleares 5 e 6, bem como o valor médio da taxa de contagem do canal 10, respectivamente câmaras de ionização compensada e detector de B-10. Tais medidas são obtidas a partir da irradiação das folhas de ouro a 100 watts de potência, valor este estimado pela técnica de análise por ruído neutrônico em relatório anterior de comissionamento

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  • IPEN-DOC 25042

    DINIZ, RICARDO . Comissionamento : previsão de massa crítica do núcleo do reator IPEN/MB-01 tipo placa. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-RMB-005-00-RELT-080-01). Restrito.

    Título do projeto: Reator Multipropósito Brasileiro (RMB)

    Abstract: Este relatório de comissionamento apresenta um procedimento experimental para a previsão de massa crítica do núcleo do reator IPEN/MB-01 com elementos combustíveis tipo placa, utilizandoa técnica do inverso da multiplicação subcrítica (1/M).

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  • IPEN-DOC 25041

    MURA, LUIZ E.C. . Comissionamento : procedimento de teste de queda das barras de controle no reator IPEN/MB-01 (teste integrado do MAB com as barras de controle). São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-RMB-005-00-RELT-077-00). Restrito.

    Título do projeto: Reator Multipropósito Brasileiro (RMB)

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  • IPEN-DOC 25040

    MURA, LUIZ E.C. ; BITELLI, ULYSSES D. . Comissionamento : procedimento para o carregamento e descarregamento dos elementos combustíveis do núcleo do reator IPEN/MB-01. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-RMB-005-00-RELT-075-00). Restrito.

    Título do projeto: Reator Multipropósito Brasileiro (RMB)

    Abstract: Este relatório descreve o procedimento para o comissionamento das operações de carregamento e descarregamento dos elementos combustíveis do núcleo do Reator IPEN/MB-01

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  • IPEN-DOC 25036

    MURA, LUIZ E.C. . Comissionamento : procedimento para o recebimento, manuseio e estocagem de elemento combustível tipo placa novo no reator IPEN/MB-01. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-RMB-005-00-RELT-069-00). Restrito.

    Título do projeto: Reator Multipropósito Brasileiro (RMB)

    Abstract: Este procedimento de comissionamento trata do processo de recebimento e dos testes das operações de manuseio e armazenamento dos elementos combustíveis tipo placa novos no reator IPEN/MB-01. Também faz parte dos objetivos deste procedimento, testar a inserção ou retirada das Placas Combustíveis avulsas dos Elementos Combustíveis Desmontáveis e a inserção ou retirada das Placas nas Caixas de Estocagem de Placas.

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  • IPEN-DOC 25035

    MOLNARY, LESLIE de . Arquivo meteorológico da torre A e torre D da CNAAA – período 2000-2017. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Julho, 2018. (IPEN-CEN-PSE-IPPG-006-00-RELT-001-00). Restrito.

    Título do projeto: Prestação de Serviços Tecnológicos

    Abstract: Esse documento apresenta uma análise do arquivo de dados meteorológicos da Central Nuclear Almirante Álvaro Alberto (CNAAA), localizada em Angra dos Reis (RJ), para o período de 2000 a 2017 e que será utilizado pela empresa Tetra Tech Brasil para avalizar o estudo de condições meteorológicas extremas (velocidade do vento, temperatura e precipitação) na área do Complexo de Manutenção Especializada (CME) do Estaleiro e Base Naval (EBN) que a Marinha do Brasil (MB) está construindo no município de Itaguaí (RJ). Devido à ausência de dados meteorológicos no local do empreendimento do EBN, foi informado à Tetra Tech que os dados meteorológicos a CNAAA podem, em primeira análise, ajudar a complementar as informações meteorológicas do estudo de condições meteorológicas extremas, uma vez que, os dados da CNAAA já são coletados a muitos anos pelo sistema de meteorologia, assim como, a distância entre a CNAAA e o EBN de cerca de 63 km e a localização de ambos os empreendimentos na faixa litorânea do Estado do Rio de Janeiro, assegura que os principais fenômenos de mesoescala e de grande escala sinótica podem ser assumidos atuando quase que ao mesmo tempo. As condições meteorológicas locais no EBN, que eventualmente possam apresentar algum mecanismo de circulação diferenciado gerado pela configuração topográfica e/ou disposição do empreendimento em relação à proximidade do oceano, que não apenas as características gerais das circulações de mesoescala e de escala sinótica na região, poderão ser melhor estudadas e caracterizadas quando da implementação e operação continuada do sistema de meteorologia da EBN. Eventualmente, esses mecanismos locais poderão potencializar algum dos parâmetros meteorológicos avaliados (velocidade do vento, temperatura e precipitação pluviométrica).

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  • IPEN-DOC 25034

    YAMAGUCHI, MITSUO . Análise de criticalidade do transporte de elementos combustíveis do núcleo do reator IPEN/MB-01 tipo placa. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Setembro, 2018. (IPEN-CEN-PSE-CCN-008-00-RELT-001-00). Restrito.

    Título do projeto: Prestação de Serviços Tecnológicos

    Abstract: Este relatório apresenta a análise de criticalidade dos elementos combustíveis que serão transportados do Centro de Combustível Nuclear (CCN) para o prédio do Reator IPEN/MB-01. A análise foi feita com o sistema SCALE4.4a.

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  • IPEN-DOC 25033

    CABRAL, F.V.; PELEGRINO, M.T.; SEABRA, A.B.; RIBEIRO, M.S. . Effects of methylene blue-mediated photodynamic inactivation associated to NO-releasing chitosan nanoparticles on cutaneous leishmaniasis in mice. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 272-272.

    Abstract: Cutaneous leishmaniasis (C L) is a ehronie disease developed by parasites of the genus Leishmania that promotes destruetive.and ulcerated lesions. The available treatments are limited beeause of side effeets, resistanee and toxieity. Reaetive oxygen speeies and nitrie oxide (NO) are potentially toxic to these parasites; Photodynamie inaetivation (PDI) involves the generation af oxidative stress and has been explored as an altemative treatment once it is less expensive and no reports about resistanee have been describedY Additionally, several studies indicate that the administration of exogenous NO donors represents an interesting strategy against CL.3 The aim of this work was to explore the effects Df methylene blue (MB)-mediated PDI in assoeiation with encapsulated NO donors (S-nitroso-MSA) in chitosan nanoparticles (CSNPs) on CL in BALB/e mice using real time bioluminescence. Promastigotes of L. (L) amazonensis transgenie line expressing luciferase were used. Sixteen BALB/e miee were infected in the left footpad with 1.106 promastigotes. After 4 weeks, mice were randomly assigned to experimental groups (n=4): Control (non-treated), PDI (treated only with PDI), PDI+CSNP (submitted to PDI and S-nitroso-MSA-CSNPs) and CSNP (treated only with S-nitroso-MSA-CSNPs). PDI was administered in two sessions separated by 24 h and CSNPs (80 eM) were applied immediately after the second PDI session. PDI was performed using a red LED (0= 660 ± 22 nm), MB (100 IlM), irradiance of 100 mW/cm2 and radiant exposure of 150 J/cm2 • parasite burden was analyzed through luciferase deteetion by bioimaging in the first 96 h following treatment and every week during 4 weeks. Statistically significant differences were considered when p < 0.05. Test groups presented significant reduction in parasite load compared to control during all experimental period. Twenty-four-h after treatments, parasite burden was lower for PDI+CSNP group but no statistically signifieant difference was observed when compared to other test groups. After 48 h, all test groups were similar. Besides, parasite load in test groups remained lower than control following 1, 2,3 and 4 weeks post-treatment. Under conditions used in this study, we conclude that CSNPs were not able to enhance MBmediated PDI efficiency in L. (L) amazonensis-induced CL in mice.

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  • IPEN-DOC 25032

    NUNEZ, SILVIA C.; BAPTISTA, ALESSANDRA; GARCEZ, AGUINALDO S.; MARTINS, RODRIGO A.L.; RIBEIRO, MARTHA S. . The role of light irradiance on methylene blue photodegradation dynamics: is all light equal?. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 252-252.

    Abstract: Methylene blue (MB) is a well-known photosensitizer (Ps) commonly used for antimicrobial photodynamic therapy (aPDT). Usually aPDT paramenters evaluation involves Ps concentration, its quantum yield for singlet oxygen production (Type II reaction) and the Ps photobleaching rate as a function of the deliveried fluence plus oxygen concentration and consumption on the medium. The role of power density is not often consider.The aim of this study is to evaluate the role of power density over MB photobleaching dynamcs evaluating the dimer/monomer ratio as well as the leuco MB formation under discrete changes in power density keeping the same light fluence. The MB was irradiated using a À = 660nm diode laser (TwinLaser, MMOptics, São Carlos, Brazil), 40mW adjustable from 10 to 10mW, 0.04cm2 • The powers of 10mW, 20mW, 30mW and 40mW were used for 300s, 150s, 100s and 75s respectively. The irradiations were carried out directly in a cover quartz cuvette with an optical path of 1 em. An acrylic mask was made to ensure the coincidence between the irradiation and the reading points. The readings were made from À = 200nm to À = 700nm and analyzed in appropriate software. The DA (dimer absorption) /MA (monomer absarption) was calculated and the ratio between visible and ultraviolet absorption was aIs o calculated. Figure 1 show the result afDA/MA for the different irradiances. Our results demonstrated that discrete changes in light irradiance leads to different dinamiccs . terms ofphotobleaching and DAIMA ratio.

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  • IPEN-DOC 25031

    DIMMER, JESICA; CABRAL, FERNANDA V. ; SABINO, CAETANO P. ; NUNEZ MONTOYA, SUSANA C.; CABRERA, JOSE L.; RIBEIRO, MARTHA S. . Photoinactivation of Leishmania amazonesis by natural anthraquinones. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 195-195.

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  • IPEN-DOC 25030

    BAPTISTA, A.; NUNEZ, S.C.; MARTIN, A.A.; RIBEIRO, M.S. . Identification of important cellular targets for antimicrobial photodynamic therapy in yeast cell through FT-IR spectroscopy. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 175-175.

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  • IPEN-DOC 25029

    SABINO, CAETANO P. ; BAPTISTA, MAURICIO da S.; RIBEIRO, MARTHA S. ; LINCOPAN, NILTON. Methylene blue uptake and intermolecular interactions in microbial cells through Fluorescence Lifetime Imaging Microscopy (FLIM). In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 16th, June 08-13, 2017, Coimbra, Portugal. Abstract... 2017. p. 82-82.

    Abstract: Antimicrobial photodynamic therapy (APDT) is a promising tool to counterattack the emerging treat of drug-resistant pathogens. The technique combines low-intensity monochromatic light with a photosensitizer compound to produce reactive oxygen species (ROS) that can damage virtually any type of biomolecules and lead to rapid ce\l death. Since some ROS present diffusion-limited reactivity, most cell damage is co-localized with photosensitizer accumulation site. Hence, imaging photosensitizer accumulation and fluorescence lifetime in the nanoscale can bring a great levei of information to further understand the ultrastructural cellular damage caused by APDT. In this study, we used a FLIM system capable of single-molecule detection to observe the accumulation and interaction sites of methylene blue (MB), a very broadly-used photosensitizer, in yeast, and Gram-positive and Gram-negative bacterial cells, Our data shows fluorescence lifetime contrast, with nanometric resolution, among different cellular structures such as cell wall, membrane and DNA. The images evidentiate differential MB accumulation in microbial cells and the existence of two different populations of MB molecular species: those interacting mostly with the solvent (short-lived, - 0.8 ns) and those interacting with biomolecules (Iong-lived, -2 ns), The short-lived fluorescence predominates in the mucoid capsule of Gram-negative bacteria and cell-wall ofyeast and Gram-positive bacteria while longlived MB fluorescence shows preferential accumulation in DNA-rich sites 1 • It is marked in yeast nucleus and exclusively inside bacterial cells. In fact, literature supports that MB intercalation in nucleic acids stabilizes its excited-states leading to increased "fluorescence "lifetime and efficiency of singlet-oxygen production2 . Our data brings evidence that this sOli of phenomena can be observed by FLIM in the nanoscale and this should bring new insights to the photophysical, photochemical and biological mechanisms of photodynamic therapy.

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  • IPEN-DOC 25028

    INTERNATIONAL ATOMIC ENERGY AGENCY (Ed.); BALLINGER, J. (Colab.); BRUCHERTSEIFER, F. (Colab.); DOLLÉ, F. (Colab.); FUKUMORI, N. (Colab.); JALILIAN, A. (Colab.); KRASIKOVA, R. (Colab.); KVATERNIK, H. (Colab.); LYASHCHENKO, S. (Colab.); OCAK, M. (Colab.); OSSO, J. (Colab.); PANDEY, U. (Colab.); SEIMBILLE, Y. (Colab.); TODDE, S. (Colab.) . Quality control in the production of radiopharmaceuticals. Vienna: International Atomic Energy Agency, 2018. 150 p. (IAEA TECDOC series, 1856).

    Abstract: Radiopharmaceuticals are central to nuclear medicine applications for the diagnosis and therapy of human diseases, especially cancers and cardiovascular diseases. In the past few decades, advances in the production and quality control of emerging radiopharmaceuticals have led to the production of new radiopharmaceuticals and the availability of new production routes and methods for existing agents. Various new diagnostic agents in the field (such as 68Ga radiopharmaceuticals and generators) as well as therapeutic agents (such as alpha emitters) have already been added to the clinician toolkit. However, the lack of generic and peer-reviewed quality control guidelines and recommendations for their application in human patients is a major concern. To address this need, and in response to requests from Member States and professional societies, the IAEA developed this publication on quality control in the production of radiopharmaceuticals. It is expected to be of use for all professionals involved in the production and quality control of radiopharmaceuticals worldwide. This publication is an outcome of the work of an international team of experts in the field between 2016 and 2018. The IAEA wishes to thank the experts for their contributions. Special thanks are due to J. Ballinger (United Kingdom) for compiling the material, and J.S. Vera Araujo (Bolivarian Republic of Venezuela) for her editorial support. The IAEA officer responsible for this publication was A.R. Jalilian of the Division of Physical and Chemical Sciences.

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  • IPEN-DOC 25027

    BUSTILLOS, OSCAR V. . A espectrometria de massas e a química analítica. Revista Analytica, v. 16, n. 96, p. 36-37, 2018.

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  • IPEN-DOC 25024

    VIEIRA, A.; SAMAD, R.E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Ablação a laser com pulsos ultracurtos do aço DIN 16MnCr5: um estudo do processo de furação / Laser ablation with ultrashort laser pulses in steel DIN 16 MnCr5: a study of drill process. In: CONGRESSO BRASILEIRO DE ENGENHARIA DE FABRICACAO, 9., 26-29 de junho, 2017, Joinville, SC. Anais... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2017.

    Abstract: A indústria automobilística tem como um de seus principais desafios, e consequentemente, foco de pesquisa, a redução do coeficiente de atrito entre alguns componentes e sistemas presentes nos automóveis. Um dos grandes benefícios dos avanços nesta área é o aumento da vida útil dos componentes e a melhor eficiência do motor. Desta maneira, uma das formas propostas pela tribologia para a redução de atrito é a texturização de superfícies por laser. Neste trabalho, foi abordada a interação de pulsos laser de femtossegundos com o aço DIN 16MnCr5, utilizado na indústria automotiva. Objetivou-se buscar os melhores parâmetros de processo para obter micro cavidades com pouca ou nenhuma zona afetada pelo calor e sem a presença de rebarbas e material ressolidificado, presentes na texturização com laser de pulsos longos (nanossegundos). Para a realização do estudo foi utilizada a técnica de escaneamento diagonal, D-Scan, para determinação dos limiares de ablação em função da sobreposição de pulsos. Também foram realizados estudos de formação das cavidades com a variação da posição do ponto focal e do perfil espacial do feixe laser. São apresentados resultados de análises obtidas por microscopia óptica e de varredura e interferometria de luz branca.

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  • IPEN-DOC 25025

    HERRERA, CRISTHIANO C. ; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Development and control of microfluidic systems. In: WORKSHOP INFO, 1., 01 de julho, 2017, Recife, PE. Resumo expandido... 2017.

    Abstract: The first stage of the project was to perform tests for controlled and optimized machining of BK7 optical glass by femtosecond laser. Parameters such as energy, overlapping pulses, and the focal position variation were investigated for a better extraction of the material. Microchannels, microvalves, micropumps, mixers, reactors, heaters and other components were developed to compose applied microfluidic systems. Microchannels built in BK7 glass separated by a PDMS film form the basis of the microfluidic circuits. The reagent flow control is done by pneumatic mini-valves controlled by an Arduino microcontroller through a Labview platform. This work shows the components developed and two microfluidic systems created. The first contains a microfluidic circuit capable of replicating enzyme-linked immunosorbent assays (ELISA) with a much lower cost of materials. The second has a microfluidic circuit for the production of NaYF4 fluorescent nanocrystals specially used as markers in images of biological systems.

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  • IPEN-DOC 25026

    GOMES, MAURILIO P. ; SANTOS, IGOR P. dos ; COUTO, CAMILA P. ; MUCSI, CRISTIANO S. ; COLOSIO, MARCO A.; ROSSI, JESUALDO L. . Têmpera ao ar de insertos de assentos de válvulas obtidos com aço ferramenta AISI D2. In: CONFERENCIA BRASILEIRA SOBRE TEMAS DE TRATAMENTO TERMICO, 8., 21-24 de maio, 2017, Indaiatuba, SP. Anais... 2017.

    Abstract: A obtenção de insertos de assentos de válvulas por metalurgia de pó usando uma mistura de pó de ferro e aços rápidos ou aços ferramenta está atendendo os requisitos para a substituição do cobalto e chumbo em peças comerciais, visando a redução de custo e evitando a toxicidade do chumbo. O objetivo do presente trabalho foi o de tratar termicamente e caracterizar os insertos de assentos de válvulas sinterizados obtidos utilizando-se uma mistura de pós. Essa mistura de pós foi constituída pelo aço ferramenta AISI D2, ferro, sulfato de manganês, carboneto de nióbio, grafite, estearato de zinco e cobre. O ciclo de temperatura da têmpera ao ar foi determinado por meio do termopar tipo k acoplado a um sistema de aquisição de dados. As propriedades físicas e mecânicas foram medidas em relação à dureza aparente dos insertos, densidade aparente e a sua resistência à ruptura radial. A caracterização microestrutural foi realizada utilizando-se a microscopia óptica, microscopia eletrônica de varredura e espectroscopia por dispersão de energia. Os insertos temperados ao ar e duplamente revenido a 500 °C mostraram os melhores resultados no que tange a dureza e resistência à ruptura radial.

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  • IPEN-DOC 25022

    PERES, JOSE C.G.; HERRERA, CRISTHIANO da C. ; ROSSI, WAGNER de ; VIANNA JUNIOR, ARDSON dos S.. Analysis of a microreactor for synthesizing nanocrystals by computational fluid dynamics. In: WORLD CONGRESS OF CHEMICAL ENGINEERING, 10th, October 01-05, 2017, Barcelona, Spain. Proceedings... 2017.

    Abstract: A microreactor designed to synthesize nanocrystals was built applying laser pulses with duration of femtoseconds in a quartz board. This precise machining technology allowed dimensioning the microchip cross section as a trapezoidal shape with base lengths of 120 μm and 200 μm and depth of 150 μm. The microchip is comprised of four inlets for reactants, a mixing section with 40 curves after the inlet section to ensure proper mixing of the species and 22 serpentine channels, with 22,000 μm length each, to allow crystal growth. Flow field throughout the microchip was investigated by computational fluid dynamics considering inlet flow rates between 12.5 and 2000 μL min-1. Hexahedral meshes were used to discretize the geometry as its cross section is uniform and to reduce the total number of elements. Advection terms were solved by the high resolution scheme. Numerical solutions were converged when the maximum residual value was less than 10-4 and the domain imbalance was less than 1%. Flow throughout the channels is laminar as the maximum Reynolds number observed is 850. The tridimensional velocity profile is a paraboloid whose vertex is influence by the centrifugal force: at the curved sections, such force accelerates flow towards the outer part of the channels, moving the maximum velocity point to this zone. The centrifugal force also creates secondary flows. These structures enhance mixing in the direction perpendicular to the main flow and behave like turbulent flows in macroscopic systems, allowing proper mixing without additional power consumption. Proper coupling between microchip geometry and its operating conditions was verified by simulating the dispersion of a non-reactive tracer injected in one of the inlet ports while feeding the others with water. For low flow rates, the tracer flows parallel to the water stream up to half of the mixing section and full mixing occurs after the second serpentine channel. For flow rates higher than 250 μL min-1, it shows secondary fluxes are intensified and promote mixing after both the third curve at the mixing section and at the beginning of the serpentine channels after the fourth reactant inlet, ensuring better conditions if the desired reaction is limited by contact between the reactants.

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  • IPEN-DOC 25016

    BRASCHI, GIOVANI F.; EIRAS, JOSE A.; BARBOSA, PATRICIA A. ; ROSSI, WAGNER de ; CARNEIRO, MARCELO B. . Desenvolvimento de material em gradação funcional de metal duro e aço rápido para ferramenta de corte / Development of functionally graded material of cemented carbide and high speed steel for cutting tool. In: CONGRESSO BRASILEIRO DE ENGENHARIA DE FABRICACAO, 9., 26-29 de junho, 2017, Joinville, SC. Anais... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2017.

    Abstract: Material em gradação funcional (Functionally Graded Material – FGM) tem sido considerado como uma nova classe de material, na qual materiais com propriedades distintas são unidos na forma de um gradiente, formando uma unidade estrutural com propriedades não uniformes. O objetivo deste trabalho é apresentar a caracterização de amostras em gradação funcional de metal duro e aço rápido. Para tanto, foram utilizados pós de metal duro (K20) e aço rápido (T6), que foram sinterizados por uma técnica comumente conhecida como SPS (Spark Plasma Sintering). A caracterização foi feita a partir da avaliação da microestrutura em microscópio laser confocal e eletrônico de varredura, determinação da densidade relativa pelo princípio de Arquimedes e avaliação do perfil de dureza Vickers ao longo seção transversal das amostras. Os resultados mostraram uma microestrutura com ausência de trincas de origem térmica, com maior valor de densidade relativa de 98,70% e com variação no perfil de dureza ao longo da espessura da amostra, o que evidencia propriedades não uniformes.

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  • IPEN-DOC 25023

    LARA, J.A.C.; COUTO, C.P. ; COLOSIO, M.A.; ROSSI, J.L. ; ABBADE, L.M.. Influence of spot welding parameters on Al-Si coated 22MnB5 for automotive application. SAE Technical Paper, n. 2017-36-0225, p. 1-6, 2017. DOI: 10.4271/2017-36-0225

    Abstract: The application of press hardening steels (PHS) Al-Si coating has been increasing in body in white vehicles as an approach to meet the demands of safety and CO2 reduction regulations. The vehicle structures with PHS largely depend on the integrity and the mechanical performance of the spots weld. During the spot welding process, intermetallic phase may appear in function of the chemical composition of the steel and coating. One of these intermetallics is the Fe-Al phase which brittleness decreases the strength of the weld joint. In this study, resistance spot welding (RSW) experiments were performed in order to evaluate the influence of the welding parameters of single-lap joints PHS - 22MnB5 steel grade. Welded samples of the Al-Si coated PHS steel as received, i.e., before any heat treatment and stamping, were evaluated by means of glow discharge optical emission spectroscopy (GDOES) technique that allows a quick and accurate evaluation of the chemical composition profile along the spot weld thickness. The GDOES results showed that the squeeze welding parameter has the higher influence on cupper diffusion at the Al-Si-Fe layer. The pre-burn current and welding current showed the higher influences in Fe-Al diffusion. The pulse technique and post-heat treatment had had the lower influences in Fe-Al diffusion.

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  • IPEN-DOC 25013

    GOMES, MAURILIO P. ; SANTOS, IGOR ; COUTO, CAMILA ; MUCSI, CRISTIANO ; ROSSI, JESUALDO L. ; COLOSIO, MARCO. P/M valve seat inserts: air quenching and characterization. SAE Technical Paper, n. 2017-01-5014, 2017. DOI: 10.4271/2017-01-5014

    Abstract: This work consists of evaluating the influence of heat treatment on sintered valve seat insert (VSI) obtained with two different highspeed steels powders and one tool steel: AISI M3:2, AISI M2 and AISI D2, respectively. The high-speed / tool steel powders were mixed with iron powders and additives such as manganese sulphide, zinc stearate, graphite and niobium carbide. All the high-speed / tool steel powders had its particle size distribution and morphology analyzed. The heat treatment of the VSI consisted of air quenching followed by double tempering it in seven different and equidistant temperatures, ranging from 100 °C until 700 °C. A data acquisition system with a thermocouple type k attached to the samples was used to determine the air-quenching cooling rate. The mechanical and physical properties measurements were carried out, i.e., apparent density, apparent hardness and crush radial strength. The microstructural evaluation consisted of etching the VSI and then analyzing it using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the VSI obtained with the AISI M3:2 and M2 high-speed steel powders mixtures showed the best results regarding its apparent hardness and crush radial strength after air quenching and double tempering it at 600 °C.

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  • IPEN-DOC 25012

    ROCHA, FLAVIO R. ; ANGELINI, MATHEUS ; HENRIQUES, HELOISE R.; SOARES, JOSIANE S. ; SILVA, PAULO S.C. ; FAVARO, DEBORAH I.T. . Metal and trace element assessment in bottom sediments from medium Tietê River Basin, by INAA and ICP OES techniques. In: INTERNATIONAL NUCLEAR CHEMISTRY CONGRESS, 5th, August 27 - September 01, 2017, Gothenburg, Sweden. Abstract... 2017. p. 104-104.

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  • IPEN-DOC 25011

    BORDON, L.; KRUPINSKI, A.; SILVA, J.M.; FAVARO, D. ; GUSSO-CHOUERI, P.; ABESSA, D.M.; CAMPOS, B. de. Metal bioaccumulation and Metallothioneins induction in blu crabs Callinectes danae exposed to lead (Pb). In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th., September 07-10, 2017, Santos, SP. Abstract... 2017. p. 20-20.

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  • IPEN-DOC 25021

    BARABAS, ROBERTA de C. ; SABUNDJIAN, GAIANE . The use of a neuroscience-based methodology to demystify and teach about the benefits of the nuclear field: neuroscience applied to nuclear energy teaching. In: SIMPOSIO INTERNACIONAL SOBRE EDUCACION, CAPACITACION, EXTENSION Y GESTION DEL CONOCIMIENTO EN TECNOLOGIA NUCLEAR, 2., 13-17 de novembro, 2017, Buenos Aires, Argentina. Anais... 2017.

    Abstract: Science, technology and innovation play an essential role in helping countries increase the quality of life they offer their citizens. Since the discovery of nuclear fission in the 30s, the peaceful applications of nuclear technology have benefited several fields. Improved crops, preservation of food, health advance – specially for the diagnosis and treatment of cancer –, environment protection and a stable supply of energy can be cited as contributions of nuclear technology for global wellbeing. Despite its benefits the nuclear energy is still addressed with prejudice. Accidents in nuclear field have contributed for its negative image. Prejudice against nuclear energy lead to misconceptions on the theme, which interfere with authorities’ decision on the development of new nuclear technology. Education is the starting point for public acceptance of nuclear technology. Educational neuroscience is an emerging scientific field that explores the interactions between biological processes and education and helps identify and change implicit associations. This paper aims to demonstrate how the previous knowledge may interfere with the implicit associations towards a source of energy. The first steps of a neuroscience-based methodology in progress are presented in this paper: a) a pretest with specialists of the nuclear field; b) a subsequent test with lay subjects; and c) comparison of the results from the pretest and test. A future step consists of applying neuroscience principles to Brazilian science teachers to identify and modify implicit attitudes towards nuclear technology to promote an assertive teaching-learning process The global educational scenario has demonstrated absence of neuroscience-based methods for the nuclear technology teaching and that represents an opportunity for developing strategic teaching methods that will help demystifying the theme consequently improving public acceptance of this type of technology. Once the real scenario is demystified, the population will have a broad vision of all contributions of the nuclear field.

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  • IPEN-DOC 25020

    CARDOSO, ELIZABETH C.L. ; OLIVEIRA, RENE R. ; MACHADO, GLAUSON A.F. ; MOURA, ESPERIDIANA A.B. . Study of flexible films prepared from PLA/PBAT blend and PLA E-beam irradiated as compatibilizing agent. In: IKHMAYIES, SHADIA (Ed.); LI, BOWEN (Ed.); CARPENTER, JOHN S. (Ed.); LI, JLAN (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); FIRRAO, DONATO (Ed.); ZHANG, MINGMING (Ed.); PENG, ZHIWEI (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); BAI, CHENGUANG (Ed.); KALAY, YUNUS E. (Ed.); GOSWAMI, RAMASIS (Ed.); KIM, JEONGGUK (Ed.). Characterization of Minerals, Metals, and Materials. Gewerbestrasse, Switzerland: Springer International Publishing AG., 2017. p. 121-129, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-319-51382-9_14

    Abstract: Plastics global annual production exceeds 250 million tons and more than 40% of the total plastic production is used as packaging materials. In recent years polymeric materials derived from biomass have received great attention due to scarce petroleum resources and environmental concerns. PLA is one of the most extensively studied bio-based and bio-compostable aliphatic polyesters; nevertheless, high brittleness and low toughness limits its application. Blending PLA with PBAT (Poly(butylene adipate-co-terephthalate)), an aliphatic-aromatic copolyester, was the solution found due to its high toughness and biodegradability. Differences between PLA and PBAT solubility parameter values lead to the formation of immiscible blends as well as reduction in their mechanical performance besides a poor morphology; so, 5% of pre-irradiated PLA and a previous compatibilized PLA/PBAT (EcovioTM) were added to PLA/PBAT blends in order to improve miscibility phases. Investigations were accomplished on phase morphology (SEM), mechanical properties, thermal behavior and X-ray diffractions (XRD).

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  • IPEN-DOC 25019

    BENTO, R.T.; CORREA, O.V. ; FERRUS FILHO, A.; PILLIS, M.F. . Estudo quantitativo do processo de degradação térmica de fibras de aramida. In: SIMPOSIO DE ANALISE TERMICA, 8., 13-15 de agosto, 2017, Ponta Grossa, PR. Resumo... 2017. p. 45-45.

    Abstract: Fios de aramida são fibras têxteis de alto desempenho, apresentando excelentes propriedades físico-químicas que favorecem a sua utilização em aplicações onde há a necessidade de tecnologia avançada. O presente trabalho tem como objetivo principal o estudo e análise quantitativa do comportamento de dois tipos diferentes de fio de aramida – 1100 dTex e 3300 dTex – durante o processo de degradação térmica, por meio da técnica de análise termogravimétrica (TGA). Para caracterização estrutural, morfológica e composição química das amostras foram realizados ensaios de microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva (EDS) e difração de raios-X (DRX). Os resultados obtidos demonstraram que as fibras de aramida apresentam estrutura cristalina, exibindo uma morfologia superficial homogênea e de baixa rugosidade. Verificou-se que as fibras em estudo possuem boa estabilidade térmica. A decomposição térmica dos fios de aramida 1100 dTex ocorre no intervalo de 493ºC – 629 ºC, enquanto que a degradação térmica da aramida 3300 dTex se inicia a aproximadamente 504ºC e se completa em torno de 644ºC, o que permite concluir que a aramida 3300 dTex é dotada de excelente resistência térmica, quando comparada a outros materiais têxteis.

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  • IPEN-DOC 25018

    SANTAELLA, CESAR K.; PILLIS, MARINA F. . Effect of rare earth elements on the boronizing process. In: SENAFOR, 37th; INTERNATIONAL FORGING CONFERENCE, 21th; NATIONAL SHEET METAL FORMING CONFERENCE, 20th; INTERNATIONAL SHEET METAL FORMING CONFERENCE, 7th; BRDDRG CONGRESS, 4th; INTERNATIONAL CONFERENCE ON MATERIALS AND PROCESSES FOR RENEWABLE ENERGIES – BRAZIL/RS, 7th; INTERNATIONAL CONFERENCE ON SURFACE ENGINEERING IN MATERIAL FORMING, October 04-06, 2017, Porto Alegre, RS. Proceedings... 2017.

    Abstract: Boronizing is a thermo-chemical process consisting on the diffusion of the chemical element boron into metallic substrates, aiming at producing on the metal surface a closed layer of borides, which are elements extremely hard and chemically inert. Steels, for example, exhibit substantially higher hardness values (1,600 to 2,000HV) than nitrided steels (650 to 900HV) due to the formation of iron borides. The combination of high hardness and low friction coefficient of this boride layer greatly contributes to endure the main mechanisms of wear: adhesion, abrasion and superficial contact fatigue. The use of the boronizing process, however, is limited due to the elevated process temperatures. To overcome this limitation, recent studies pointed to the use of rare earth elements as catalysts of the process. This work will present the state of the art of these developments.

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  • IPEN-DOC 25017

    LAPA, NELBIA; MARTINS, LUIZ C.; MADEIRA, ALZIRA; WELLELE, OLIIVER; SABUNDJIAN, GAIANE; LEE, SEUNG ; STEINROTTER, THOMAS. Simulation of a station black out at the Angra 2 NPP with Melcor Code. In: TECHNICAL MEETING ON THE STATUS AND EVALUATION OF SEVERE ACCIDENT SIMULATION CODES FOR WATER COOLED REACTORS, October 09-12, 2017, Vienna, Austria. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2017.

    Abstract: The interest in evaluating the level of resistance of a nuclear power plant in response to an accident that exceeds the project bases, increased significantly after the Fukushima-Daiichi accident. Melcor is an integrated code, developed by Sandia National Laboratories, used to model and simulate the evolution of severe accidents in nuclear power plants. The Melcor modeling is general and flexible, making use of a “control volume” approach in describing the thermal hydraulic response of the plant. Reactor-specific geometry is imposed only in modeling the reactor core. The reactor cooling circuit and the four SG are represent by two model-loops, a single loop with the pressurizer and an agglutinated triple loop. All active safety systems which depend on AC power are assumed to be unavailable in this analysis. The most important strategies assumed were primary side depressurization and additional makeup water to reactor coolant system. The passive severe accident management measures primary bleed, secondary side bleed, passive injection from feedwater system and firefighting pool available. In Brazil there is the Almirante Álvaro Alberto Nuclear Power Plant that has two plants in operation, and one of them is Angra 2, which started operating in 2001. This unit is a pressurized water reactor type with electrical output of about 1350 MW. The objective of this work is to present a summary of the severe accident caused by a station black out condition using the Melcor 1.8.6 code. The main result of the study is an evaluation of RPV lower head integrity during a severe accidents scenario. The results will be useful to an independent assessment into the detailed processes involved by the management guidelines for one scenario severe accident in Angra 2.

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  • IPEN-DOC 25015

    SILVA, ANDRE F. ; COSTA, PRISCILA ; MACHADO, NOE G.P. ; SAMAD, RICARDO E. ; ZEZELL, DENISE M. ; RAELE, MARCUS P. ; ZAMATARO, CLAUDIA B. . Analysis of temperature on microscope slide by a boron pulsed laser deposition process. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: A boron thin ¯lm can be used for neutrons conversion and in electrically charged particles and further detection. Since boron has a high evaporation temperature and the thickness of the boron layer needs to have few microns, pulsed laser deposition also known as PLD can be used. When producing thin ¯lms with the PLD technique, the target absorbs energy promoting the material ablation creating a plasma plume that deposits material on a substrate, thus creating a thin ¯lm. Since all the deposition occurs in a vacuum chamber, the residual heat of the plasma that condensate at the substrate can build up, thus potentially source of concern if the substrate sensitive to temperature somehow. This work reports the analysis of the variation of temperature in a microscope slide (substrate) as a function of the energy of femtosecond laser pulses. For measuring the substrate temperature a type-K thermocouple was used together with associated electronics. The thermocouple was ¯xed to the back of substrate with thermal grease for vacuum and connected to the microchip using a feed through in the vacuum chamber. Was detected the increase of the substrate+¯lm starting at 6oC from initial temperature (room) for the minimal laser energy 100 microjoules (25 femtoseconds).

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  • IPEN-DOC 25014

    FERREIRA, MERILYN ; PASK, HELEN; WETTER, NIKLAUS U. . Laser Raman intracavidade de Nd:YLF/KGW bombeado lateralmente emitindo em 1147 e 1163 nm. In: SIMPOSIO DE APLICACOES DE OPTICA E LASERS, 2., 04-06 de outubro, 2017, São José dos Campos, SP. Resumo... São José dos Campos: Instituto de Estudos Avançados, 2017.

    Abstract: Foi investigado neste trabalho um laser Raman intracavidade de Nd:YLF/KGW na configuração de bombeio lateral. Para a geração do laser fundamental foi usado um cristal de Nd:YLF bombeado por um diodo, emitindo em 792 nm, na configuração lateral gerando um comprimento de onda de 1053 nm. Como cristal Raman foi usado um KGW bombeado em suas duas linhas Raman principais, 768 cm-1 e 901 cm-1, conseqüentemente gerando dois comprimentos de onda Raman, 1147 e 1163 nm, respectivamente. Dentro da cavidade a densidade de potência do laser fundamental é muito alta, desta maneira a configuração Raman intracavidade irá produzir uma conversão Raman mais eficiente [1]. Aliando-se a isso as boas características do Nd:YLF em configuração lateral [2] fomos capazes de gerar uma potência de saída em 1163 nm de 4,85W em regime multímodo, correspondendo à uma eficiência diodo-Raman de 12,2%, a eficiência diodo-Raman em modo TEM00 alcançou 7,5%. Para a emissão em 1147 nm foi atingido 1,47W de potência de saída com uma eficiência diodo-Raman de 3,7%. Até o momento não encontramos um laser Raman intracavidade de Nd:YLF/KGW em bombeio lateral reportado na literatura.

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  • IPEN-DOC 25010

    ACHUSIM-UDENKO, AMAUCHE C.; RENATA, COIDA D.S.; VALENZUELA-DIAZ, FRANCISCO R.; ONYEDIKA, GERALD O.; MOURA, ESPERIDIANA A.B. ; OGWUEGBU, MARTIN C.; VALENZUELA-DIAZ, GRACA. Preparation and characterization of clay exfoliation and vegetal fibre on properties of recycled low density polyethylene. In: IKHMAYIES, SHADIA (Ed.); LI, BOWEN (Ed.); CARPENTER, JOHN S. (Ed.); LI, JLAN (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); FIRRAO, DONATO (Ed.); ZHANG, MINGMING (Ed.); PENG, ZHIWEI (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); BAI, CHENGUANG (Ed.); KALAY, YUNUS E. (Ed.); GOSWAMI, RAMASIS (Ed.); KIM, JEONGGUK (Ed.). Characterization of Minerals, Metals, and Materials. Gewerbestrasse, Switzerland: Springer International Publishing AG., 2017. p. 429-437, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-319-51382-9_47

    Abstract: This work aims to incorporate Mgbee clay, vegetal fibre ( Costus afer ) in recycled low density polyethylene (rLDPE). The incorporation of clay and vegetal fibre in rLDPE was carried out using a twin screw extruder machine and the nano composites were obtained. The nano composites were characterized by the Young’s modules test, tensile tests, bending test, XRD, SEM, DSC, and TG and other properties evaluated. The results of morphological and thermal properties showed a good interaction between the clay, and rLDPE as compared to neat rLDPE.

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  • IPEN-DOC 25009

    COIADO, RENATA D.S.; LAZO, GISELE D.; OLIVEIRA, RENE R. ; RODRIGUES, RITA C.L.B.; MOURA, ESPERIDIANA A.B. . Polymer blend based on recycled polyethylene and ethylene vinyl acetate copolymers reinforced with natural fibers from agricultural wastes. In: IKHMAYIES, SHADIA (Ed.); LI, BOWEN (Ed.); CARPENTER, JOHN S. (Ed.); LI, JIAN (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); FIRRAO, DONATO (Ed.); ZHANG, MINGMING (Ed.); PENG, ZHIWEI (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); BAI, CHENGUANG (Ed.); KALAY, YUNUS E. (Ed.); GOSWAMI, RAMASIS (Ed.); KIM, JEONGGUK (Ed.). Characterization of Minerals, Metals, and Materials. Gewerbestrasse, Switzerland: Springer International Publishing AG., 2017. p. 689-697, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-319-51382-9_76

    Abstract: Agricultural residues, which are produced with large quantities annually throughout the world, may be used as reinforcement plastic to replace the wood and produce particleboard for application in the development of low cost construction elements and reduced environmental impact. The main aims of this study was to investigate the effects of agricultural wastes and glass residues addition on the properties of recycled-HDPE/EVA blend for use in particleboard manufacture. The recycled-HDPE/EVA blend reinforced with corncob fiber (15 wt%), coffee parchment (15 wt%) and glass residues (1 wt%) were processed by melt extrusion, using a twin screw extruder and injection molding machine to obtain specimen test samples. The samples were characterized by mechanical test, XRD, TG, DSC, and FE-SEM analysis to understand the nature of interaction between the fillers reinforcement and recycled-HDPE/EVA blend matrix and their properties were discussed.

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  • IPEN-DOC 25008

    ROVANI, SUZIMARA ; SANTOS, JONNATAN J. ; CORIO, PAOLA; FUNGARO, DENISE A. . Adsorption study of acid orange 8 dye using silica nanoparticles obtained from sugarcane ash. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, November 27-30, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Developing of new adsorbents becomes a very important need, especially because of the increase of contaminants present in rivers, oceans and any other water body capable of became potable. Biosorbents has a special feature, because they can solve two problems at the same time, once they are prepared from a natural source, giving a utility for wasted materials, and bioremediate a water body, adsorbing contaminants on their surface. In this context, the properties of a biosorbent prepared from sugarcane ash by surfactant mediated synthesis has been studied to the adsorption of acid orange 8 dye, a model molecule, aiming future applications for removal of emerging contaminants of water. According to the results of adsorption kinetic (Fig. 1A), the acid orange 8 dye removal was higher than 89% and 95% in 4 h of contact time for an initial concentration of 200 and 150 mg L-1, respectively. FTIR-ATR analyses (Fig. 1B) indicated the presence of bands: at 799 and 446 cm-1 are due to symmetric stretching of siloxane groups, at 1058 cm-1 is due the Si–O–Si asymmetric stretching, at 2925 cm-1 and 2850 cm-1 are due to the bending of –CH3 and –CH2, respectively, for silica-CTAB sample and additionally, at 1031, 689 and 641 cm-1 are due sulfur groups (S=O), out-of-plane deformation of ring and aromatics groups, respectively, of acid orange 8 dye. In TGA analysis (Fig. 1C), the peak between 150 to 235 °C for silica-CTAB sample has been attributed to the unbound CTAB less stabilized bonding sites on the silica surface due to hydrophobic– hydrophobic interactions of interdigitated CTAB and the peak around 256 °C indicates a stronger bonding of the surfactant to the silica surface due to the electrostatic binding of the ammonium cation head group to the electronegative silica surface [1]. For the silica-CTAB + dye sample, the substitution of the interdigitated CTAB of a second layer by dye was observed by the disappearance of the DTG peak between 150 to 235 °C. The displacement the DTG peak of 256 for 300 °C and appearance of the DTG peak around 435 °C are related to the dye adsorption. These aspects demonstrate the potential of silica nanoparticles obtained from sugarcane ash as new biosorbent for removal of organic compounds, such as, dye from aqueous solution and can be used to alleviate environmental problems.

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  • IPEN-DOC 25007

    ROVANI, SUZIMARA ; SANTOS, JONNATAN J. ; CORIO, PAOLA; FUNGARO, DENISE A. . Surfactant mediated synthesis of silica nanoparticles using sugarcane ash waste as renewable source. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, November 27-30, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Green silica from renewable source can be used in very different materials, since addictive for construction materials or polymers to traditional products as glass, silicone rubber as well as source for silicon. Brazil is the world’s largest producer of sugarcane and generates huge amounts of sugarcane ash waste (SAW) which is a rich source of silica. This work investigates a method to produce pure silica nanoparticles from SAW. Initially, sodium silicate was obtained from sugarcane ash waste adapting the methodology published by Alves, et al., 2017. Subsequently, sodium silicate was added to a mixture of water/butyl alcohol (1:1) with 2.5% wt. of hexadecyltrimethylammonium bromide under constant stirring at 60 °C. Then, 0.5 mol L-1 sulfuric acid solution was added slowly to suspension until pH 4 and the resulting gel was aged at 60 °C for 8 h. The aged nanosilica gel was washed with distilled water, filtered and oven dried at 120 °C. The silica nanoparticles were characterized by different techniques. In the Figure 1 can be observed energy dispersive spectra (EDS) and transmission electron microscopy (TEM) images of sugarcane ash waste (A and B) and of silica nanoparticles (C and D). EDS of SAW shows the presence of several different elements (being Si, Fe, Al, P, Cl and S more abundant) and only Si and O were observed after synthesis procedure (Cu signal comes from TEM grid). Transmission electron microscopy image of samples exhibit a drastic alterations of the material size ranging from several micrometers (Fig. 1C) to less than 20 nm (Fig. 1D). The results indicate that was possible to obtain pure silica in a nano- size from waste material to reduce disposal and pollution problems.

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  • IPEN-DOC 25006

    BENTO, RODRIGO T. ; OLIVEIRA, EDUARDO C. de ; SZURKALO, MARGARIDA ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Characterization and photocatalytic behavior of TiO2 thin films grown by MOCVD process. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, November 27-30, 2017, Guarujá, SP. Proceedings... 2017.

    Abstract: This research aims to evaluate the influence of the thickness on the photocatalytic behavior of TiO2 thin films grown at 400ºC by metalorganic chemical vapor deposition. Titanium dioxide films with 280 and 468 nm of thickness were grown on borosilicate substrates. The photocatalytic behavior was evaluated by monitoring the degradation of methyl orange dye under UV light for 2h. The results show that both films presented anatase crystalline phase and that increasing the thickness the grain size and the roughness were also increased. The best photocatalytic performance was attributed to the film of 468 nm of thickness that exhibited 40% of dye degradation after 2h under UV light.

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  • IPEN-DOC 25005

    SZURKALO, MARGARIDA ; OLIVEIRA, EDUARDO C. de ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Synthesis and characterization of TiO2 films obtained by sol-gel method. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, November 27-30, 2017, Guarujá, SP. Proceedings... 2017.

    Abstract: Borosilicate coated titanium dioxide thin films were produced by the sol-gel method. The films were calcinated at 450°C for 20 minutes for crystalization. X-ray diffration analyses show that before the heat treatment the film was amorphous and after that it crystallized in anatase phase presenting mean grain size of 34 nm and RMS roughness of 8 nm. The crystallized film was used as photocatalist in the degradation of methyl orange dye presenting an efficiency of 25% after 2h under UV light.

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  • IPEN-DOC 25004

    SANTANA, JULYANA G. ; ORTIZ, ANGEL ; OLIVEIRA, RENE R. ; RANGARI, VIJAY K.; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B. . Mechanical, thermal, morphology and barrier properties of flexible film based on polyethylene-ethylene vinyl alcohol blend reinforced with graphene oxide. In: IKHMAYIES, SHADIA (Ed.); LI, BOWEN (Ed.); CARPENTER, JOHN S. (Ed.); LI, JIAN (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); FIRRAO, DONATO (Ed.); ZHANG, MINGMING (Ed.); PENG, ZHIWEI (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); BAI, CHENGUANG (Ed.); KALAY, YUNUS E. (Ed.); GOSWAMI, RAMASIS (Ed.); KIM, JEONGGUK (Ed.). Characterization of Minerals, Metals, and Materials. Gewerbestrasse, Switzerland: Springer International Publishing AG., 2017. p. 49-57, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-319-51382-9_7

    Abstract: Ethylene-vinyl alcohol (EVOH) copolymers are widely used in the food packaging industry as gas barrier properties to oxygen, organic solvents, and food aromas. EVOH is very sensitive to moisture and its gas barrier ability deteriorates in high relative humidity conditions. This work aims to prepare flexible films based on melt-blending high density polyethylene (HDPE) and ethylene-vinyl alcohol (HDPE/EVOH/EVA blend) reinforced with graphene oxide (GO). The HDPE/EVOH/EVA/GO flexible films were prepared by twin-screw extrusion and blown film extrusion processing. The flexible films samples were characterized by tensile tests, TG, DSC and FE-SEM analysis and the correlation between properties was discussed. In addition, the oxygen permeability tests were performed at 23 °C, 0 and 90% relative humidity using an OX-TRAN (MOCON Inc.).

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  • IPEN-DOC 25003

    IZIDORO, JULIANA de C. ; MIRANDA, CAIO da S. ; GUILHEN, SABINE N. ; FUNGARO, DENISE A. . Chemical, mineralogical and environmental characterization of combustion byproducts generated from mineral coal used for electricity production. In: INTERNATIONAL CONFERENCE ON MATERIALS CHEMISTRY, 13th, July 10-13, 2017, Liverpool, UK. Proceedings... Cambridge: Royal Society of Chemistry, 2017. p. 1-14.

    Abstract: The coal combustion by-products, bottom ash (BA), fly ash from cyclone filter (CA) and fly ash from bag filter (FA), generated in a Brazilian thermoelectric power plant, were characterized by Xray fluorescence, X-ray diffractometry and leaching and solubilization tests. The material retention systems used in the Brazilian power plant from where these by-produtcts were sampled are showed in Figure 1. The three types of coal ashes presented similar chemical composition, with a total content of main oxides (SiO2, Al2O3 and Fe2O3) above 72% and were classified as class F (according to ASTM). The analysis of ash enrichment factor showed that arsenic, zinc and lead concentrate mainly on FA, whereas the elements that presented the greatest enrichment in the bottom ash (BA) and therefore present low volatility are K and Mg. All ashes presented quartz, mullite and magnetite as crystalline phases. In the leaching and solubilization study, the FA sample was considered hazardous and classified according to Brazilian regulation as Class I solid waste, whereas CA and BA samples were considered non-hazardous and not inert solid wastes and classified as Class II-A. Therefore, FA sample from this Brazilian power plant must be discarded only after treatment or stringent disposal criteria must be followed to avoid contamination on site.

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  • IPEN-DOC 25002

    VEGA, O. ; LOPES, P.R. ; AMARAL, P.O.; GONSCHOROWSK, G.; OLIVEIRA, J.P.; FABBRO, R.; MESQUITA, K.A.; GIMENEZ, M.P.; REDIGOLO, M. . Preparación de muestras del médio ambiente para análisis por médio de técnicas cromatograficas. In: SIMPOSIO LATINOAMERICANO DE QUIMICA ANALITICA Y AMBIENTAL, 12th, April 25-27, 2017, Manizales, Colombia. Proceedings... Bogotá, Colombia: Pontificia Universidad Javeriana, 2017.

    Abstract: Este artículo explora la ciencia de la preparación de muestras para matrices sólidas, líquidos y gases, utilizados en el laboratorio del Centro de Química y Medio Ambiente del IPEN. Extracción de neonicotinoides del agua por LLE (Liquid-Liquid Extraction), extracción de hidrocarburos aromáticos policíclicos (PAHs) del agua atraves de DLLME (Dispersive liquid - liquid micro extraction) y el uso de extracción en fase sólida SPE (Solid Phase Extraction) para el análisis de hormonas en agua son descritos. Limites de detección que utilizan estas técnicas son descritas en este trabajo.

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  • IPEN-DOC 25001

    LEVY, D.S. ; SORDI, G.M.A.A. ; RODRIGUES, D.L. ; CARNEIRO, J.C.G. . Information and communication technologies for appropriate communication in the workplace. In: CONGRESO REGIONAL DE SEGURIDAD RADIOLOGICA Y NUCLEAR, 11th, April 16-20, 2018, La Habana, Cuba. Proceedings... 2018.

    Abstract: Brazil is one of the 5th largest countries on earth. It is geopolitically divided into five regions, with large between-country distances and plenty of radioactive facilities throughout the country. Professional continuing education is a must and a challenge. This paper discusses a web-based project designed to provide effective communication about occupational exposure, using creative, innovative and practical Internet solutions to link geographically distant workers to high-quality reliable information. This web-based-project counts on concepts, definitions and theory about radiological protection issues, such as optimization programs and ionizing radiation monitoring procedures. Moreover, the content presents discussions related to national and international recommendations, such as potential exposure, which is currently one of the most important research fields in radiological protection. Only few publications develop expressively the issue and there is still lack of knowledge and uncertainties. Risk definition itself can assume different meanings, even among scientific community. To respond to this challenge, this project discusses potential exposures through question-and-answer topics addressing particular attention to effective actions towards safety which can be incorporated into labor practice in the workplace. For discussions to be effective, all content is based on ICRP and IAEA valid recommendations and official reports, in addition to scientific papers published in major international congresses. This project aims to provide radioactive facilities reliable updated communication, to inform as many people as possible, contributing to develop workers´professional skills and to improve safety culture in workplace.

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  • IPEN-DOC 25000

    LEVY, D.S. ; SORDI, G.M.A.A. ; RODRIGUES, D.L. ; CARNEIRO, J.C.G.G. . Information and communication about occupational exposure in workplace. In: SIMPOSIO INTERNACIONAL SOBRE PROTECCION RADIOLOGICA EN MEDICINA, August 20-24, 2017, Arequipa, Peru. Proceedings... 2017.

    Abstract: Medical applications of ionizing radiation are essential for protecting and improving human health. The radiological protection objective is to keep doses as low as reasonably achievable, maximizing dose reduction in order to obtain the necessary results for patients in diagnostic and interventional radiology, nuclear medicine and radiotherapy. There is plenty of information, published papers and studies about radiological protection for patients, regarding interventional radiology, nuclear medicine, radiotherapy, biomedical research, among others. Nevertheless, medical and paramedical personnel themselves are also exposed to radiological risks associated with the various uses of radiation in medicine. This paper discusses some considerations about radiological protection in workplace, as well as the need of more accurate information and communication about occupational exposure and potential exposures in medical practice. We believe that this type of information and communication will be helpful for exposed individuals knowingly while voluntarily helping - other than in their occupation - in the care, support or comfort of patients undergoing medical diagnosis or treatment and for visitors of the patients.

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  • IPEN-DOC 24999

    MANTECON, JAVIER G. ; MATTAR NETO, MIGUEL . One-way fluid-structure interaction model to study the influence of the fluid velocity and coolant channel thickness on the stability of nuclear fuel plates+. In: ABCM INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 24th, December 3-8, 2017, Curitiba, PR. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2017.

    Abstract: In nuclear research reactors, the fuel elements are frequently composed of parallel, flat or curved plates. A major problem of that fuel element configuration is the hydraulic instability of the plates caused by high coolant velocities. Thin plates contain the fuel and they are separated by narrow channels through which the coolant flows to remove the heat generated. In this study, a numerical analysis was conducted to examine the fluid-structure interaction of a flat fuel plate bounded by two coolant channels. The loads caused by the fluid flow are calculated using a Computational Fluid Dynamics model implemented in ANSYS CFX, and the plate structural responses are determined using a Finite Element Analysis model implemented in ANSYS Mechanical. The goal of the present work is to estimate the amount of deformation of a fuel plate when there is an increment of the fluid velocity and a variation in the thickness of the coolant channels.

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  • IPEN-DOC 24998

    SILVA, K.C.; GUILHEN, S.N.; IZIDORO, J.C. ; FUNGARO, D.A. . Removal of cadmium and zinc from aqueous solutions using zeolite synthesized from coal fly ash and industrial aluminium waste. In: ENCONTRO BRASILEIRO SOBRE ADSORCAO, 12., 23-25 de abril, 2018, Gramado, RS. Anais... 2018.

    Abstract: Coal fly ash can be used as a source of Silicon and Aluminum for 4A zeolite synthesis. It is necessary to consider the adequate proportion of Si / Al for the synthesis, so the aluminum waste from tertiary industry was used as an alternative and sustainable aluminum source. The synthesis was carried out by alkaline fusion followed by the hydrothermal treatment obtaining sodium aluminosilicate, which was then crystallized in NaOH solution. The samples were characterized by XRF, XRD and cation exchange capacity. The zeolite produced has the capacity to adsorb the Cd (II) and Zn (II) ions from aqueous solutions. The maximum adsorption capacity was 78.0 and 35.8 mg.g-1 for the Cd and Zn, respectively. The results showed that the aluminum waste and the fly ash together can be transformed into zeolite A, considered as value-added material and with promising adsorption properties.

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  • IPEN-DOC 24997

    SOUZA FILHO, E.A. de; ARAUJO, E.G. de; CORREA, O.V. ; PILLIS, M.F. . Synthesis and characterization of N-doped TiO2 thin films. In: CONGRESSO BRASILEIRO DE APLICACOES DE VACUO NA INDUSTRIA E NA CIENCIA, 38.; WORKSHOP DE TRATAMENTO E MODIFICACAO DE SUPERFICIES, 3., 21-25 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 193-194.

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  • IPEN-DOC 24996

    KIYAN, V.H.; ZEZELL, D.M. ; SAMAD, R.E.; VIEIRA JUNIOR, N.D.; BOTTINO, M.A.; SARACENI, C.H.C.. Efeito do laser de Femtossegundos no tratamento de superfície de cerâmicas à base de zircônia. Brazilian Oral Research, v. 31, suppl. 2, p. 403-403, 2017.

    Abstract: Este estudo objetivou analisar a superfície de cerâmicas à base de zircônia irradiadas por pulsos ultracurtos de um laser de Ti:Safira. Para isto, dois discos de zircônia (In-Ceram YZ® - Vita Zahnfabrik) com 15,3 mm de diâmetro foram irradiados por pulsos de 25 fs (1 fs=10-15 s) em 800 nm, com energia por pulso variando de 25 a 200 μJ, e taxa de repetição de 0,2 a 4 kHz. Cada irradiação varreu uma área de 1 × 1 mm2, com velocidades entre 0,2 e 4 mm/s, deslocamento lateral de 10 μm, e diâmetro de feixe de 40 ou 70 μm que resultaram em sobreposições de 65 ou 190 pulsos por posição, respectivamente. Uma amostra foi irradiada em atmosfera e a outra sob fluxo de argônio. Em cada uma foram feitas 24 irradiações com condições diferentes. As áreas foram analisadas por perfilometria óptica, Microscopia Eletrônica de Varredura e EDS. Foram escolhidas as áreas que apresentaram pequeno aumento de rugosidade (Ra) em relação ao material não irradiado - Ra=(0,32±0,02) μm - e menor alteração de cor, sem que houvesse alteração na composição. Os melhores resultados foram obtidos para irradiações em atmosfera por pulsos de 25 μJ, focalizados para 40 μm (densidade de energia de 2,0 J/cm2), e taxas de repetição de 0,2, 1 e 4 kHz, com rugosidades de (0,40±0,03) μm, (0,50±0,05) μm e (1,19±0,11) μm, respectivamente, e para pulsos de 50 μJ e 40 μm de diâmetro a 1 kHz, com Ra=(0,40±0,03) μm.

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  • IPEN-DOC 24995

    LOPES, D.S.; PEREIRA, D.L.; ZEZELL, D.M. ; MOTA, C.C.B.O.; MELO, L.S.A.; GOMES, A.S.L.. Influência da irradiação com laser Er,Cr:YSGG sobre a resistência de união de braquetes ortodônticos. Brazilian Oral Research, v. 31, suppl. 2, p. 395-395, 2017.

    Abstract: A proposta deste estudo foi investigar os efeitos da irradiação com laser Er,Cr:YSGG na resistência de união da interface esmalte-braquete. Após aprovação pelo Comitê de Ética em Experimentação Animal da Universidade Federal de Pernambuco (protocolo número 23076.015869/2015-65), foram selecionados 40 incisivos bovinos, divididos aleatoriamente em quatro grupos (G) (n=10), três experimentais e um controle, com diferentes doses de irradiação com laser de Er,Cr:YSGG sobre a superfície do esmalte: G1 - 54,1 mJ/ 1,1 W, 20 Hz; G2 - 83 mJ/ 1,7W, 20 Hz; G3 - 120 mJ/ 2,41 W, 20 Hz; G4 - controle, condicionamento de esmalte com ácido fosfórico a 37%. Os espécimes foram analisados através da tomografia por coerência Óptica (OCT) e da microscopia eletrônica de varredura (MEV) para verificação das alterações promovidas no esmalte. Para análise estatística foram utilizados os testes de Tukey, ANOVA e o Qui-quadrado, adotando um nível de significância de 5%. O G3 apresentou a resistência de união mais elevada (8,0 MPa). A análise de ANOVA não revelou diferenças estatisticamente significativas entre os grupos (p = 0,1310). A análise qualitativa das imagens pelo OCT e MEV revelam que as superfícies irradiadas apresentaram microfissuras que auxiliam a penetração da resina.

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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.