Submissões recentes

  • IPEN-DOC 23706

    CIONE, FRANCISCO C. ; SOUZA, ARMANDO ; MARTINEZ, LUIZ ; ROSSI, JESUALDO ; BETINI, EVANDRO G. ; ROLA, FABIO; COLOSIO, MARCO A.. Measurements of residual stresses in aluminum wheels using the techniques of XRD, strain gages and FEA simulation - a comparison. SAE International Journal of Materials and Manufacturing, v. 9, n. 3, p. 685-687, 2016. DOI: 10.4271/2016-01-0426

    Abstract: Studying the formation and distribution of residual stress fields will improve the wheel safety operational criteria among other gains. Many engineering specifications, manufacturing procedures, inspection and quality control have begun to require that the residual stress of a particular component to be evaluated. It is known that these residual stress fields could be added to the effects of a system load (tare weight plus occupation of vehicle, traction, braking and torque combined). The mathematical tools for modeling and simulations using finite elements had evolved following the increasing computing power and hardware cost reduction. On the other hand, the experimental testing, offers specific physical component behavior and with the use of statistical tools, it is possible to predict the real behavior of the component when in operation. The experiments undertaken used the X-ray diffraction technique and the drilling method with rosette type strain gages. The experimental results were convergent with similarity to those obtained using FEA simulation over critical region for global and superficial in the principal stresses mode. The relevance of the present study and research on residual stresses meets safety improvements in car’s wheel industry.


  • IPEN-DOC 23705

    SENNA, MARY L.G.S. ; AQUINO, AFONSO R. . The ecological footprint of tourism in Jalapão/TO/Brazil. In: WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY, 18th, November 24-25, 2016, London, United Kingdom. Proceedings... . p. 1739-1744.

    Abstract: The development of tourism causes negative impacts on the environment. It is in this context, through the Ecological Footprint (EF) method that this study aimed to characterize the impacts of ecotourism on the community of Mateiros, Jalapão, Brazil. The EF, which consisted in its original a method to construct a land use matrix, considering some major categories of human consumption such as food, housing, transportation, consumer goods and services, and six other categories from the main land use which are divided into the topics: land use, degraded environment, gardens, fertile land, pasture and forests protected by the government. The main objective of this index is to calculate the land area required for the production and maintenance of goods and services consumed by a community. The field research was conducted throughout the year of 2014 until July 2015. After the calculations of each category, these components were added according to the presented method in order to determine the annual EF of the tourism sector in Mateiros. The results show that the EF resulting from tourism in Mateiros is 2,194.22 hectares of land required for tourism activities in the region. The EF of tourism was considered high, nevertheless, if it is added the total of hectares needed annually for tourism activities, the result found would be 2,194.22 hectares needed to absorb the CO2 emissions generated in the region directly from the tourism sector.


  • IPEN-DOC 23704

    SENNA, MARY L.G.S. ; AQUINO, AFONSO R. ; DUTRA, VERUSKA C. ; TOLENTINO, CARLOS H.C.. Quality of life of the beneficiaries of the government’s bolsa família program: a case study in Mateiros/TO/Brazil. In: WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY, 18th, November 21-22, 2016, Paris, France. Proceedings... . p. 1304-1310.

    Abstract: The quality of life index, despite elucidating many discussions, the conceptual subjectivity of the term does not show precision, and consequently, many researchers seek to develop methods aiming to measure this concept, bringing it to a more concrete approach. In this study, the quality of life index method was used to analyze the population of Mateiros, Tocantins, Brazil for quality of life. After data collection, it was compared the quality of life index between the population and the group of beneficiaries of the Brazilian government assistance program Bolsa Família (Family Allowance). Some of the people interviewed receive financial aid from the federal government program Bolsa Família (22%). Comparisons were made among the final score of the quality of life index of the Mateiros population and the following factors: Gender, age, education, those working or not with tourism and those who receive or do not receive the Bolsa Família. It was observed that only the factor, Bolsa Família (p-score 0.0138), shows an association with quality of life improvement, noticing that those who have financial aid had a higher quality of life improvement than the rest of the population. It was concluded that, government assistance has shown a decisive element on the enhancement of Mateiros population quality of life, indicating that similar actions should be maintained.


  • IPEN-DOC 23703

    DUTRA, VERUSKA C. ; AQUINO, AFONSO R. . Monitoring of key indicators of sustainable tourism in the Jalapão State Park/Tocantins: a case study of environmental indicators. In: WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY, 18th, November 24-25, 2016, London, United Kingdom. Proceedings... . p. 1745-1750.

    Abstract: Since the 1980s, global tourism activity has consolidated worldwide to become an important economic contributor, and consequently, the sociocultural and environmental impacts are starting to become evidenced. This raises the need of discussing about actions for sustainable tourism that should be linked not only to the economy, but also to the environment and social aspects. The work that is going to be presented is part of a doctoral research project in Sciences undertaken at the Sao Paulo University, Brazil. It aims to analyze whether the monitoring of the tourism sector with a focus on sustainability is applicable or not, through those indicators, put in a case study in the Jalapão State Park (JSP) conservation unit, in the state of Tocantins, Brazil. This is a study of an interdisciplinary nature that had the deductive method as its guide. We concluded that the key points of the sustainable tourism, when analyzed with the focal point in environmental indicators, are an important evaluation and quantification tool of that activity in the study locus. It displayed itself as an adequate tool for monitoring, thus decoding, the main environmental impacts that occur in tourism regions and their intensity, which is made possible through analysis, and has the objective to trace ways to prevent and correct the presented impacts.


  • IPEN-DOC 23702

    DUTRA, VERUSKA C. ; SENNA, MARY L.G.S. ; AQUINO, AFONSO R. . A proposal of a method to measure the satisfaction indicator of the local community concerning tourism: a case study of Jalapão State Park, Tocantins. In: WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY, 18th, November 24-25, 2016, London, United Kingdom. Proceedings... . p. 1751-1757.

    Abstract: Tourists bring many benefits to a local community, encouraging it to be involved in that activity; however, it may also have detrimental effects like garbage, noise, violence, external culture and the damaging of the natural environment among others, which may promote community dissatisfaction. The contact between the tourist and the local community is a concern, especially when the community is located near protected areas. In this case, the community must know the tourist destination well, so it can collaborate in the tourism development without harming the environment. In this context, the present article aims to demonstrate the results of a research study conducted as part of a doctorate program in Sciences from the University of Sao Paulo, Brazil. It had as an objective to elaborate a methodology proposal to measure the local community satisfaction indicator, with applicability on a case study in the Mateiros community located in the surrounding area of the Parque Estadual do Jalapão –PEJ conservation unit in the state of Tocantins, Brazil. This is a study of an interdisciplinary nature that had the deductive method as its guide. The indicator result is going to be presented in this study. It pointed out as negative factors: there is no involvement between the local community and the tourism sector, and there is also dissatisfaction with regard to the town’s basic services. The study showed as positive the local community knowledge about the various attractions in the surrounding area and that the group recognizes the importance of the tourism for the town and life. Concerning the methodology that was used, the results showed that it can collaborate in seeking actions of improvement and involvement of the community in the planning and development of the local tourism. It comes out as an efficient analysis tool, thus enabling the perceiving of the local community point of view.


  • IPEN-DOC 23701

    BENEDETTI, S. ; PUGA, R.S.; MARTINS, P.A. ; MENGATTI, J. ; FUKUMORI, N.T.O. ; MATSUDA, M.M.N. . A proposal for validation of the radiochemical purity of Technetium Tc99m Pentetate. In: CONGRESO DE LA ASOCIACIÓN LATINOAMERICANA DE SOCIEDADES DE BIOLOGÍA Y MEDICINA NUCLEAR, 25., 18-21 de noviembre, 2015, Punta del Este, Uruguay. Resumo... .


  • IPEN-DOC 23689

    LANGE, CAMILA N. ; FIGUEIREDO, ANA M.G. ; ENZWEILER, JACINTA. Rare earth elements in soil profile and groundwater of a vehicle impound scrapyard. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: The number of motor vehicles has increased drastically over the past decade in Brazil. As such, vehicle impound scrapyard (SIV) overcrowding has become a challenge in many Brazilian regions, and environmental problems associated with this activity are becoming more acute. Contamination by metals such as Pb, Fe, Cd and Ni under and in the vicinity of soils of discarded vehicle scrapyards have been reported in several studies,1 but information about rare earth elements in this environment is scarce. Currently, one of the main end uses for rare earth elements (REEs) are for automobile catalysts and petroleum refining, as well as the use in fuel and oil additives, and more recently, also in electronic devices. The aim of this study was to evaluate the content of REEs in soil profiles and groundwater in the area of a SIV located in the city of Ribeirão Pires, a municipality in the metropolitan region of São Paulo state, Brazil. Three monitoring wells were installed, one upstream (PM1), without influence of the vehicles, and two downstream (PM2 and PM3). Sampling was performed with a mechanical probe and the wells were lined by a 2” diameter geomechanical PVC tube and filter. Nine samples were collected in plastic liners: four in PM1 (0-0.75 m; 0.75-1.30 m; 1.30-2.10 m; 2.10-2.70 m) three in PM2 (0-0.50 m; 0.50-0.85 m; 0.85-1.45 m) and two in PM3 (0-1.0 m; 1.0-1.75 m). Groundwater was sampled (one sample in PM1, two in PM2 and one in PM3) using a low flow peristaltic pump and pH, electrical conductivity, redox potential and temperature were measured with a a multiparameter probe. Water samples were filtered with using 60 mL plastic syringes coupled with 0.45 μm pore size PVDF filters. Soil samples were dried at 40 ºC and sieved (< 2 mm). Before and after sieving samples were disaggregated, homogenized, quartered. Samples were ground using agate jars and balls and a planetary mill. Neutron activation analysis was employed to determine REEs in soil samples, and ICP-MS was the analytical technique for groundwater analysis. The REEs mass fractions in the soil profiles varied between 0.083 and 137.9 μg/g in PM1, with significantly higher values in the first layer (0-0.75 m), between 0.52 and 99.1 μg/g in PM2 and between 0.33 and 121.9 μg/g in PM3. The groundwater showed the highest REEs concentrations in PM2 (0.02 to 3.29 ng/mL), followed by PM1 (0.005 to 0.33 ng/mL) and PM3 (0.002-0.14 ng/mL). Such values are in the range of expected REEs values in groundwater, considering physicochemical and sampling conditions. The chondrite normalized REEs patterns of the soil samples show enrichment of light REEs over heavy REEs, with a small positive anomaly of Ce in PM3. According to DERSA,2 the main lithotypes of the area comprise granites and metamorphic rocks. Wedepohl3 quotes average Ce values in granitic rocks as 104 μg/g, which is in accordance with the results of this study. Overall, the findings indicate that the values of REEs in the study area are, up to now, mostly geogenic


  • IPEN-DOC 23700

    MELLO-CASTANHO, SONIA ; SANTOS, SILAS C. ; CAMPOS, L.L. ; YAMAGATA, C. . Synthesis and processing of yttrium dysprosium-doped silicate. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: Sol gel route was used to synthetize Dy-doped Ytrium disilicate (Dy- Y2Si2O7) powders. The well-defined composition was a concern of the precision of the synthesis process, which stoichiometrically controlled to attain single crystalline phase and obtain fine particles in order to use as raw material for prototyping of bioinspired matrix from Luffa Cylindrica (LCy). The surface of the LCy was carefully prepared by chemical attack and the rheological studies of the aqueous suspensions performed with the synthetized Dy-doped Ytrium disilicate was previously studied. The optimized conditions were used to obtain porous and homogeneous replicas. The pieces biomorphic structure shaped were sintered at 1500 °C / 7h. The prototype was tested as a device for illumination from the burning of biomass in flame and showed good yield. The disilicate emission thermoluminescence doped with dysprosium demonstrated enhance the lumen capacity of this device.


  • IPEN-DOC 23698

    SANTOS, PAULO R.S.; MOURA, JANDEILSON L.; FAUSTINO, WAGNER M.; ESPINOLA, JOSE G.P.; BRITO, HERMI F.; FELINTO, MARIA C.F.C. ; TEOTONIO, ERCULES E.S.. Intramolecular energy transfer process on bis- and tris-diketonate trivalent europium complexes with phosphine and arsine oxide ancillary ligands. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: The present work reports about the investigation of the intramolecular energy transfer in the [Eu(-diketonate)2(NO3)(L)2] and [Eu(-diketonate)3(L)2] compounds, where -diketonate = 2-thienoyltrifluoroacetone (TTA) and dibenzoylmethane (DBM), L = triphenylarsine oxide (TPAsO), tricyclohexilphosphine oxide (TCHPO) and tributylphosphine oxide (TBPO). The synthesized complexes were characterized by complexometric titrations, CHN elemental analysis, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. Then spectroscopic properties of these systems were investigated based on the diffuse reflectance, excitation and emission spectra as well as decay times of 5D0 emitting state. Experimental data of CHN analysis and complexometric titrations of the synthesized complexes are in agreement with theoretical data for their respective formulas. FTIR spectra in the infrared region show that the coordination of β-diketonate and phosphine oxide ligands to the Eu3+ ions occurs by the oxygen atoms of C=O, As=O and P=O groups, respectively. The excitation spectra of the samples exhibited broad bands associated to S0-S1 transitions on coordinated organic ligands indicating an operative intramolecular energy transfer to the Eu3+ ion levels. Photoluminescent properties were investigated through intensity parameters 2 and 4, spontaneous emission rates (Arad), luminescence lifetime (), emission quantum efficiency (). The highest values of  were found for [Eu(-diketonate)2(NO3)(L)2] complexes in the range of 56-89%, due to the more efficient energy transfer between the Triplet state of the organic ligand and 5D0 level of Eu3+ ion. It was observed that [Eu(-diketonate)3(L)2] compounds displayed the shortest luminescence lifetime probably owing to the back energy transfer process, which results in higher values of Anrad. The intensity parameters 2 and 4 changed only slightly when auxiliary ligands were changed in the first coordination sphere of the [Eu(-diketonate)2(NO3)(L)2] and [Eu(-diketonate)3(L)2] compounds. The high values of emission quantum efficiency suggest that the novel compound can be applied as Light Conversion Molecular Devices (LCMDs).


  • IPEN-DOC 23697

    YAMAGATA, CHIEKO ; PAGANELLI, MARJORIE; SILVA, FERNANDO S.; CASTANHO, SONIA R.H. de M. . Rare earth silicates powder synthesis for use as SOFC electrolyte. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: Rare-earth apatite type materials (general formula A10-xM6O26±y; where A=rare earth, M=Si, Al, Ge or P) have been investigated as alternative solid electrolyte materials for SOFC (Solid Oxide Fuel Cells) [1]. This is because of their higher ionic conductivity than conventional zirconia electrolytes, at temperatures between 600ºC and 700ºC. Among apatite rare-earth silicates, the lanthanum silicates, exhibit the highest values of oxide ion conductivity at intermediate temperatures. Lanthanum silicates with general formula La9.33+x (SiO4)6 O2+1.5x (0 ≤ x ≤ 0.67) exhibit high ionic conductivity and low activation energy values at intermediate temperatures (500–700°C). Therefore, they are considered as promising electrolytes for intermediate temperature SOFCs (IT-SOFCs) [2]. Doping into La or Si sites can enhances the ion conductivity of apatite-type lanthanum silicates (ALS). It was observed, for example, to the Mg-doped lanthanum silicate, La9.533(Si 5.7Mg0.3)O26 [3]. The main effort to the actual application of ALS as IT-SOFC electrolyte remains in the difficulty to prepare dense ceramics. High temperatures (1600–1800 °C) and prolonged time are required to obtain a relative density of 90% for ALS prepared by conventional solid-state synthesis route. Secondary phases, such as LaSi2O5 and La2Si2O7 could also remain in the system. Those phases deteriorate the conductivity of the ceramic electrolyte. To synthesize powders with higher sinterability wet-chemical routes, such as, sol–gel, modified sol-gel, molten salts, freeze-drying, co-precipitation and acid citric methods has been practiced. In his work, pure lanthanum silicate La9,56(SiO4)6O2,34 and Mg-doped lanthanum silicate, La9,8Si5,7Mg0,3O26,4 were successfully synthesized by using the sol-gel followed by precipitation method. The crystalline apatite phase of La9,56(SiO4)6O2,34 and La9,8Si5,7Mg0,3O26,4 was obtained by calcination at 900ºC. The density measurements revealed that the samples have a density of higher than 90%.


  • IPEN-DOC 23696

    SILVA, IVAN G.N.; MUSTAFA, DANILO; RODRIGUES, RODRIGO V.; MERIZIO, LEONNAM G.; FELINTO, MARIA C.F.C. ; BRITO, HERMI F.. Y2O2SO4:Eu3+ nanomaterials synthesis by a benzenecarboxylate method. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: Luminescent nanomaterials have been mainly investigated in recent years because of significant differences in structure and performance from the bulk [1,2]. Most preparation methods of nanosized luminophores need high temperatures or complicated experimental procedures. Rare earth (RE) 5-Sulfoisophthalic acid complexes (RE(STMA)·4H2O) decompose to rare earth sulfates RE2O2SO4:Eu3+ in one step at low temperature, the compounds were annealed at 500, 600, 700, 800, 900 and 1000 °C [3]. This work reports a new low temperature preparation method of the Y2O2SO4:Eu3+ nanomaterials based on benzenecarboxylate method precursors. TGA analyses (Fig. 1) show on event from 35 to 175 °C corresponding to the loss of 4 water molecules and only one decomposition event, from 490 to 670 °C (loss of organic moiety). The XRD confirms the obtainment of Y2O2SO4:Eu3+ materials without the presence of other phases up to 900 °C, after this temperature Rietveld refinement show formation of Y2O3. The excitation spectra (Fig. 2) exhibit the LMCT O→Eu band centered at 275 nm and the intraconfigurational 4f transitions of Eu3+. The excitation spectra show similar features independently of the annealing temperature, with the presence of an extra low intensity broad band in the compounds annealed at 500 and 600 °C, owing to oxycarbonated. The emission spectra (Fig. 3) exhibit only the intraconfigurational 4f transitions of the Eu3+ ion, with the presence of transitions arising from the 5DJ (J: 0, 1 and 2).


  • IPEN-DOC 23695

    KHAN, LATIF U.; ZAMBON, LUIS F.M.; BRITO, HERMI F.; FELINTO, MARIA C.F.C. . Luminescent and magnetic composites: study of iron oxide induced luminescence quenching of Eu3+ ion. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Proceedings... .

    Abstract: The bifunctional nanomaterials, co-assembling photonic and magnetic features into single entity nanostructures are remarkable for applications, such as biosensors for medical diagnosis and ionizing radiation scintillation. The preparation of these nanomaterials are accessible through facile methods, using iron oxide as core nanoparticles and RE3+ materials as luminescent center. The magnetic properties are usually due to the core Fe3O4 nanoparticles, however, the magnetic moments of the RE3+ ions are also contributed to the whole magnetization of these nanostructures. In addition, rare earth ions exhibit well-defined narrow emission bands in different spectral ranges from visible to near-infrared due to their 4f intraconfiguration transitions, giving the bifunctional nanomaterials efficient luminescent behavior. In the present work, the preparation strategy and characterizations of the bifunctional Fe3O4@Y2O3:Eu3+ Fe3O4@SiO2@Y2O3:Eu3+, Fe3O4@SiO2@Ag@Y2O3:Eu3+ and -Fe2O3@Y2O3:Eu3+ materials are discussed. The DC magnetic properties (MH and ZFC/FC curves) and photoluminescence behavior of the RE3+ composites based on the emission spectral data and luminescence decay curves are studied. The experimental intensity parameters (λ), lifetimes (), emission quantum efficiencies () as well as radiative (Arad) and non-radiative (Anrad) decay rates are calculated, in addition, based on these parameters iron oxide induced luminescence quenching of Eu3+ ion is studied.


  • IPEN-DOC 23694

    TEOTONIO, ERCULES E.S.; COSTA, ISRAEL F.; MOURA, JANDEILSON L.; FAUSTINO, WAGNER M.; CREMONA, MARCO; ADENES, RIAN E.; AVILA, HAROLDO J.C.; BRITO, HERMI F.; FELINTO, MARIA C.F.C. . Tris(2-Acyl-1,3-indandionate)aluminum(III) complexes as emitting layer in electroluminescent devices. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Abstract... .

    Abstract: This work reports about syntheses, characterization, Photo (PL) - and electroluminescence (EL) properties of the complexes presenting general formula [Al(aind)3], where aind: 2- acetyl-1,3-indandionate (acind), 2-propyl-1,3-indandionate (propind), 2-benzoyl-1,3- indandionate (bind) or 2-(4-methyl)benzoyl-1,3-indandionate (mbind). These complexes were characterized by elemental analyses, Fourier-infrared absorption spectroscopy, thermogravimetric analyses. The bilayer electroluminescent devices were prepared with the following configuration ITO/NPB/[Al(aind)3]/LiF/Al, where NPB is N,N-bis-1-naphhyl-N,N -diphenyl-1,1-bifenil-4,4-diamina. The photoluminescent spectra of all complexes are characterized by overlapped broad bands arising from both fluorescence (around 640 nm) and phosphorescence (around 525 nm) phenomena (Fig. 1 (a)). On the other hand, their OLEDs exhibited only a high electroluminescence intense band in the red spectral region that may be assigned to the phosphorescence from acyl-1,3-indandionate ligands (Fig. 1 (b)). These data reflects the highest population of excited triplet state when the complexes are electrically excited. Furthermore, the OLEDs presented emission from low tension (~12V), reaching the highest intensity around 16 V. According with these results, the tris(2-Acyl-1,3- indandionate)aluminum(III) complexes act as both efficient electron transporters and emitting layers.


  • IPEN-DOC 23693

    KHAN, L.U.; MURACA, D.; BRITO, H.F.; MOSCOSO-LONDONO, O.; FELINTO, M.C.F.C. ; PIROTA, K.R.; TEOTONIO, E.E.S.; MALTA, O.L.. Bifunctional optical and magnetic nanocomposites containing Fe3O4 grafted inorganic matrices and functionalize with RE3+ complexes. In: INTERNATIONAL CONFERENCE ON EXCITED STATES OF TRANSITION ELEMENTS, 6th, August 21-26, 2016, Polanica Zdrój, Poland. Abstract... .

    Abstract: The design of bifunctional magnetic luminescent nanomaterials containing Fe3O4 functionalized with rare earth ion complexes of calixarene and β-diketonate ligands is reported. Their preparation is accessible through a facile onepot method. These novel Fe3O4@calix-Eu(TTA) (TTA = thenoyltrifluoroacetonate) and Fe3O4@calix-Tb(ACAC) (ACAC = acetylacetonate) magnetic luminescent nanomaterials show interesting superparamagnetic and photonic properties. Besides, the preparation of bifunctional nanocomposites, co-assembling photonic (RE3+) and magnetic (Fe3O4) features into single entity nanostructures is reported through a facile method, using Fe3O4 as core nanoparticles, which were coated with SiO2 shell and further grafted with Eu3+ and Tb3+ complexes. The sophisticated structural features and morphologies of the core-shell Fe3O4@SiO2-(TTA-RE-L) nanomaterials were studied by SAXS analysis. The core mean size , shell thickness , cluster size ξ and fractal dimension DF were determined by fitting the experimental SAXS data, corroborating through Transmission Electron Microscopy images. The DC magnetic properties at temperatures of 2 and 300 K were explored in support to the structural conclusions from SAXS and TEM analyses. The magnetic contributions of the RE3+ ions to the magnetizations of the Eu3+ and Tb3+ nanocomposites were discussed. The photoluminescence properties of the Eu3+ and Tb3+ nanocomposites based on the emission spectral data and luminescence decay curves were studied (Fig.1). The experimental intensity parameters (), lifetimes (), emission quantum efficiencies () as well as radiative (Arad) and non-radiative (Anrad) decay rates were calculated and discussed, in addition, the structural conclusions from the values of the 4f-4f intensity parameters in the case of the Eu3+ ion. These novel Eu3+ and Tb3+ nanocomposites may act as red and green emitting layers for magnetic and light converting molecular devices.


  • IPEN-DOC 23692

    FELINTO, M.C.F.C. ; DIAS, C.L.; GARCIA, V.; NAKAMURA, L.K.O. ; BARBOSA, H.P.; RODRIGUES, L.C.; BRITO, H.F.; MALTA, O.M.L.; TEOTONIO, E.E.S.. Preparation of luminescent RE2-xEux(MoO4)3 (RE=Y and La) amino-functionalized silica nanoparticles for biological applications. In: INTERNATIONAL CONFERENCE ON EXCITED STATES OF TRANSITION ELEMENTS, 6th, August 21-26, 2016, Polanica Zdrój, Poland. Abstract... . p. O-8.

    Abstract: Nanomaterials are used in many areas of biological research Nanoparticles can be used as active components in various functional materials and devices of interest for bio-applications. Nanoparticles have long been signaled as a potential revolution in the way we probe and interact with biological materials and organisms. This is because they are small enough to interact with their environment at a molecular level, but strong enough to maintain useful properties such as luminescence over extended periods. However, the physical properties of the host materials with nanometer dimensions may differ markedly from those of their bulk counterparts due to the particle size-dependent influences such as structure disordering and surface defects. The development of materials incorporated in the silica has been studied since these materials exhibit intrinsic luminescent properties of the inorganic part and characteristics of the silica matrix. In the present work RE2-xEux(MoO4)3 compounds incorporated into silica particles were prepared using a microwave synthesis procedure. Then, the material was dispersed in ethyl alcohol and functionalized with APTES: 3-aminopropyltriethoxisilane. The emission spectra show broad bands when compared with the emission spectra of the own rare earth compound. The narrow lines are assigned to 5D07F0-4 transitions. Emission spectrum of the RE2-xEux(MoO4)3 @ Si dispersion showed an enlargement of the bands. It is also observed the broadened peak of the 5D07FJ transitions in the luminescent aminofunctionalized silica particles as compared with the core compound spectrum. These materials were conjugated to anti-PSA antibody and presented high efficient performance in detect PSA from the blood serum. They can concluded that particles are potential candidates for development of the bioassays acting as a biomarker.


  • IPEN-DOC 23691

    KHAN, L.U.; MURACA, D.; BRITO, H.F.; MOSCOSO-LONDONO, O.; FELINTO, M.C.F.C. ; PIROTA, K.R.; TEOTONIO, E.E.S.; MALTA, O.L.. Optical and magnetic nanocomposites containing Fe3O4@SiO2 grafted with Eu3+ and Tb3+ complexes. In: INTERNATIONAL CONFERENCE ON EXCITED STATES OF TRANSITION ELEMENTS, 6th, August 21-26, 2016, Polanica Zdrój, Poland. Abstract... . p. I-12.

    Abstract: The fabrication of bifunctional nanocomposites, co-assembling photonic (RE3+) and magnetic (Fe3O4) features into single entity nanostructures is reported through a facile method, using Fe3O4 as core nanoparticles, which were coated with SiO2 shell and further grafted with Eu3+ and Tb3+ complexes. The sophisticated structural features and morphologies of the core-shell Fe3O4@SiO2-(TTA-RE-L) nanomaterials were studied by Small-angle X-ray Scattering. The core mean size , shell thickness , cluster size ξ and fractal dimension DF were determined by fitting the experimental SAXS data, corroborating through Transmission Electron Microscopy images. The DC magnetic properties at temperatures of 2 and 300 K were explored in support to the structural conclusions from SAXS and TEM analyses. The magnetic contributions of the RE3+ ions to the magnetizations of the Eu3+ and Tb3+ nanocomposites were discussed. The photoluminescence properties of the Eu3+ and Tb3+ nanocomposites based on the emission spectral data and luminescence decay curves were studied (Fig.1). The experimental intensity parameters (), lifetimes (), emission quantum efficiencies () as well as radiative (Arad) and non-radiative (Anrad) decay rates were calculated and discussed, in addition, the structural conclusions from the values of the 4f-4f intensity parameters in the case of the Eu3+ ion. These novel Eu3+ and Tb3+ nanocomposites may act as red and green emitting layers for magnetic and light converting molecular devices.


  • IPEN-DOC 23690

    INVERNIZZI, BRUNO P. ; NEVES, MAURICIO D.M. das . Soldagem circunferencial do aço inoxidável super duplex UNS S32750 pelo processo MIG com controle CMT / Circunferencial welding aplied for inoxidable steel super duplex UNS S32750 using the process MIG with CMT control. In: CONGRESSO NACIONAL DE SOLDAGEM, 42., 28-30 de novembro, 2016, Belo Horizonte, MG. Anais... . p. 1-12.

    Abstract: This study carried out circumferential welding experiments in tubes with 3.68 mm thick. Welding was performed using MIG welding equipment with CMT Cold Metal Transfer® control and with the aid of Motoman robot and a turntable. This was to ensure the accurate positioning of the torch and that the welding was fully implemented in the 1G position, respectively. The weld joints were then evaluated visually, and the joints which present fully penetration were then subjected to tensile testing, microhardness Vickers test and metallography. The welding performed, has shown a lack of penetration for all parameters performed when welded by CMT conventional process. To avoid this problem, the weld was performed using the CMT process combined with pulsed arc, thus creating greater energy during welding, resulting in full penetration and improved surface finish. For this process which has provide fully penetration, the mechanical tests and the metallographic tests were performed and has present adequate results.


  • IPEN-DOC 23688

    CAMPOS, L.M.P. ; ZAHARESCU, T. ; BOARO, L.C.C.; SANTOS, L.K.G. ; FERREIRA, H.P. ; PARRA, D.F. . Efeito da Radiação γ em Nanopartículas de Montmorilonita Adicionadas em Compósitos Experimentais a Base de Bis-GMA/ TEGMA. In: SOCIEDADE BRASILEIRA DE PESQUISA ODONTOLOGICA, 32., 04-07 de setembro, 2015, Campinas, SP. Resumo... . p. 306-306.

    Abstract: Os efeitos da radiação gama (doses entre 25‑50 kGy) em nanopartículas de montmorilonita (MMT) Cloisite® 20A, utilizadas como carga (50% em massa), em compósitos a base bis- GMA/TEGDMA (1:1), foram estudados. A estabilidade térmica dos compósitos foi observada por meio da análise de termogravimetria (TGA). O módulo elástico (E) e a resistência à flexão (RF) foram comparadas de acordo com a dose de radiação aplicada. Os dados estatísticos de E foram analisados utilizando os testes ANOVA/ Tukey e os dados de RF os testes Kruskal-Wallis/ Tukey, devido a heterocedasticidade dos dados. Para todos os dados o nível de significância foi de 5%. A análise de difração de raio-x (DRX) permitiu observar o fenômeno de intercalação entre a matriz polimérica e a carga nanoparticulada. Os compósitos modificados com nanopartículas de MMT irradiadas apresentaram maior estabilidade térmica pelo deslocamento da temperatura de decomposição para temperaturas maiores, comparado com o grupo controle (sem radiação) e a dose de radiação influenciou diretamente o comportamento térmico. Entretanto, não houve diferença estatística para as análises de E e RF.


  • IPEN-DOC 23699

    BRITO, HERMI F.; BARBOSA, HELLIOMAR P.; FELINTO, MARIA C.F.C. ; MALTA, OSCAR L.. White light emission of the single-phased CaWO4:Tb3+,Eu3+,Dy3+ materials prepared by an environmentally friendly method. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Resumo... .

    Abstract: Trivalent rare earth (RE3+) doped tungstates [WO4]2- host matrix offers possibility to design new photoluminescent materials.1 Nowadays, there is an increasing interest of WLEDs to replace the conventional fluorescent lamps due its environment-friendliness and tuneable colours.2,3 Here we report preparation as well as the spectroscopic properties of the new highly luminescent white emitting materials Tb3+/Eu3+/Dy3+ triply-doped in CaWO4 matrix. The materials were prepared by coprecipitation method at room temperature with stoichiometry aqueous solutions of Na2WO4, CaCl2 and RECl3 (RE3+: Tb, Eu, Dy with 0.5 to 5.0 mol% of the Ca2+ amount). The RE3+ doping concentrations were identical for each rare earth ion in the range from 0.5-5.0 mol%. The XPD measurements revealed the as-prepared CaWO4:xTb3+,xEu3+,xDy3+ (x: 0.5-5.0 mol%) particles belong to the tetragonal scheelite phase with I41/a (#88) space group. The average crystallite sizes are ~11 nm. The white luminescence emission arising mainly from the 5D07F2 (Eu3+), 5D47F5 (Tb3+) and 4F9/26H15/2 (Dy3+) transitions at 614 nm (red), 545 (green) and 488 (blue), respectively (Fig. 1). The emission lifetimes of the 5D0, 5D4 and 4F9/2 emitting levels were and their values are reduced when comparing the ratio from 0.5-5.0 mol% of the RE3+ ions, respectively. The results indicate the presence of energy transfer processes between RE3+. These values could be assigned to non-radiative energy transfer contributions of the Dy3+Tb3+, Dy3+Eu3+ and Tb3+Eu3+ systems due the cross relaxation. The CIE diagram (Fig. 1 right) exhibits emissions whitish colour indicating that these materials could be suitable for solid state lighting technology.


  • IPEN-DOC 23999

    BARBOSA, HELLIOMAR P.; PEDROSO, CASSIO C.S.; FELINTO, MARIA C.F.C. ; MALTA, OSCAR L.; BRITO, HERMI F.. White light emission of the single-phase CaWO4:Dy3+ phosphors by simple synthesis and fast heating. In: BRAZILIAN MEETING ON INORGANIC CHEMISTRY, 18th, September 25-30, 2016, São Pedro, SP. Resumo... .

    Abstract: Tungstates activated by trivalent rare earth ions (RE3+) can be used for many optical devices.1 Nowadays, there is an increasing interest in white phosphors emitting to application in white-light-emitting devices (WLEDs) replacing the conventional fluorescent lamps due its ecofriendliness and tuneable colours. Here we report preparation as well as the spectroscopic properties of the single phase new highly luminescent white emitting of Dy3+ doped into the CaWO4 materials. The materials were prepared by coprecipitation method at room temperature with stoichiometry aqueous solutions of Na2WO4, CaCl2 and DyCl3 (0.1 to 5.0 mol% of the Ca2+ amount). The as-prepared materials were heated for 22 min between 900 – 1000 W in a domestic microwave oven and using Fe3O4 (60 g) susceptor as heating source. The XPD measurements revealed the CaWO4:Dy3+ particles belong to the tetragonal scheelite phase with I41/a (#88) space group. The emission arising mainly from the 4F9/26H15/2 (blue) and 6H13/2 (yellow) transitions are corresponding to the 488 and 575 nm, respectively (Fig.). At lower doping concentrations the broad band (~420 nm) is due to the WO4 group emission. Increasing the RE3+ doping concentration the main emission lines transitions of the Dy3+ are enhanced. After heating, the 1.0 mol% Dy3+ doped material exhibit a better whitish emission due to the simultaneous presence of broad band of the host in blue region and emission lines at longer wavelengths (Fig.). The lifetimes decrease monotonously in function of the Dy3+ concentration which indicates that the energy transfer from host to the Dy3+ becomes more efficient. These results suggest that CaWO4:Dy3+ could act as a white emitting phosphor in solid state-lighting technology.


  • IPEN-DOC 23998

    SANTOS, ROBINSON A. dos ; MESQUITA, CARLOS H. de ; SILVA, JULIO B.R. da ; FERRAZ, CAUE de M. ; COSTA, FABIO E. da ; MARTINS, JOAO F.T. ; GENNARI, ROSELI F.; HAMADA, MARGARIDA M. . Influence of impurities on the radiation response of the TlBr semiconductor crystal. Advances in Materials Science and Engineering, v. 2017, n. 1750517, p. 1-10, 2017. DOI: 10.1155/2017/1750517

    Abstract: Two commercially available TlBr salts were used as the rawmaterial for crystal growths to be used as radiation detectors. Previously, TlBr salts were purified once, twice, and three times by the repeated Bridgmanmethod. Thepurification efficiency was evaluated by inductively coupled plasma mass spectroscopy (ICP-MS), after each purification process. A compartmental model was proposed to fit the impurity concentration as a function of the repetition number of the Bridgman growths, as well as determine the segregation coefficients of impurities in the crystals. The crystalline structure, the stoichiometry, and the surface morphology of the crystals were evaluated, systematically, for the crystals grown with different purification numbers. To evaluate the crystal as a radiation semiconductor detector, measurements of its resistivity and gamma-ray spectroscopy were carried out, using 241Am and 133Ba sources. A significant improvement of the radiation response was observed in function of the crystal purity.


  • IPEN-DOC 23997

    PIRES, NATALIA S.M.; DANTAS, ANDREA T.; DUARTE, ANGELA L.B.P.; AMARAL, MARCELLO M. ; FERNANDES, LUANA O.; DIAS, TEREZA J.C.; MELO, LUCIANA S.A. de; GOMES, ANDERSON S.L.. Optical coherence tomography as a method for quantitative skin evaluation in systemic sclerosis. Annals of the Rheumatic Diseases, v. 0, n. 0, p. 1-2, 2017. DOI: 10.1136/annrheumdis-2016-210875


  • IPEN-DOC 23996

    PETRI, A.R. ; GONÇALVES, J.A.C. ; MANGIAROTTI, A.; BOTELHO, S. ; BUENO, C.C. . Measurement of the first Townsend ionization coefficient in a methane-based tissue-equivalent gas. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, v. 849, p. 31-40, 2017. DOI: 10.1016/j.nima.2017.01.007

    Abstract: Tissue-equivalent gases (TEGs), often made of a hydrocarbon, nitrogen, and carbon dioxide, have been employed in microdosimetry for decades. However, data on the first Townsend ionization coefficient (α) in such mixtures are scarce, regardless of the chosen hydrocarbon. In this context, measurements of α in a methanebased tissue-equivalent gas (CH4 – 64.4%, CO2 – 32.4%, and N2 – 3.2%) were performed in a uniform field configuration for density-normalized electric fields (E/N) up to 290 Td. The setup adopted in our previous works was improved for operating at low pressures. The modifications introduced in the apparatus and the experimental technique were validated by comparing our results of the first Townsend ionization coefficient in nitrogen, carbon dioxide, and methane with those from the literature and Magboltz simulations. The behavior of α in the methane-based TEG was consistent with that observed for pure methane. All the experimental results are included in tabular form in the Supplementary material.


  • IPEN-DOC 23995

    MONTEIRO, WALDEMAR A. ; PEREIRA, SILVIO A.L.; VATAVUK, JAN. Nitriding process characterization of cold worked AISI 304 and 316 austenitic stainless steels. Journal of Metallurgy, v. 2017, n. 1052706, p. 1-7, 2017. DOI: 10.1155/2017/1052706

    Abstract: The nitriding behavior of austenitic stainless steels (AISI 304 and 316) was studied by different cold work degree (0% (after heat treated), 10%, 20%, 30%, and 40%) before nitride processing. The microstructure, layer thickness, hardness, and chemical microcomposition were evaluated employing optical microscopy, Vickers hardness, and scanning electron microscopy techniques (WDS microanalysis).Theinitial cold work (previous plastic deformations) in both AISI 304 and 306 austenitic stainless steels does not show special influence in all applied nitriding kinetics (in layer thicknesses).The nitriding processes have formed two layers, one external layer formed by expanded austenite with high nitrogen content, followed by another thinner layer just below formed by expanded austenite with a high presence of carbon (back diffusion). An enhanced diffusion can be observed on AISI 304 steel comparing with AISI 316 steel (a nitrided layer thicker can be noticed in the AISI 304 steel). The mechanical strength of both steels after nitriding processes reveals significant hardness values, almost 1100HV, on the nitrided layers.


  • IPEN-DOC 23994

    BALDAN, RENATO; MALAVAZI, JEFFERSON; COUTO, ANTONIO A. . Microstructure and mechanical behavior of Al9Si0.8Fe alloy with different Mn contents. Materials Science and Technology, p. 1-8, 2017. DOI: 10.1080/02670836.2016.1271966

    Abstract: It has been reported that the detrimental effect of Fe on the mechanical properties of Al alloys can be eliminated through the addition of Mn. In this study, we examine the effects of the addition of different Mn contents (0.1, 0.2, 0.4 and 0.7 wt-% of Mn) on the microstructure and mechanical behaviour of Al9Si0.8Fe alloy. It is shown that the presence of up to 0.4 wt-% of Mn changed the platelike morphology of β-Al5FeSi into α-Al15(Fe,Mn)3Si2 with a Chinese script-like morphology. Mn contents higher than 0.4 wt-% promoted the formation of α-Al15(Fe,Mn)3Si2 phase with a polygonal morphology. The effect of the addition of up to 0.7 wt-% of Mn on the mechanical properties of Al9Si0.8Fe alloys is in fact quite negligible.


  • IPEN-DOC 23993

    CAMPOS, LUIZA ; BOARO, LETICIA; SANTOS, TAMIRIS ; SANTOS, VINICIUS; VARCA, GUSTAVO ; PARRA, DUCLERC . Chlorhexidine loaded MMT as dental composite filler: release evaluation. Revista Matéria, v. 00, n. 0, 2013.

    Abstract: Polymeric restorative materials are widely used, however polymerization shrinkage still stands as a major drawback as it allows microleakage, secondary caries, postoperative sensitivity and cusp deflection. A polymeric material with antimicrobial activity could be very useful in many dental procedures including adhesive cementation, sealants, dental adhesives and direct restorative material. The aim of this study was to develop nanocomposites for dental purposes composed by chlorhexidine loaded montmorillonite (Cloisite 30B) nanoparticles in a BisGMA / TEGDMA organic matrix. The specimens of experimental composites were synthesized with 10 % (w/w) of diacetate chlorhexidine incorporated in a MMT, as filler. The chlorhexidine release at 37 oC was evaluated in vitro in physiological solution at neutral pH for 366 hours. Drug content was estimated by UV spectroscopy at λ=255 nm. Significant drug release initiated after 96 hours and maintained throughout the experiment. In conclusion, the composite was capable of promoting chlorhexidine release over time, and such results in addition to the lack of significant weight loss (≤ 1.43 %) and the very low swelling (≤ 2.22 %) properties, revealed the strong potential of the developed composite for further dental and other biomaterial applications.


  • IPEN-DOC 23566

    POVEDA, PATRICIA N.S. ; SILVA, LEONARDO G.A. . Study of synergistic effect of light stabilizer additive, conventional and nanoparticles, applied to polyethylene films submitted to ultraviolet radiation. 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. Springer International Publishing. 2017. p. 777-785.

    Abstract: Thermoplastic materials are sensitive to ultraviolet radiation (UV), which can cause structural changes, causing variation in mechanical properties and appearance. UV range between 250 and 400 nm is considered the most aggressive to polymers, and prolonged exposure to it results in breakage and/or crosslinking chains. Light stabilizer additives, blockers or absorbers are added to the polymers for protection in order to extend the life of the final product. The choice of the adequate light stabilizer additive system depends on factors such as resin final application, thickness, geographic location of exposure, presence of fillers in the composition, contact with chemicals, among others. This study evaluates different additive systems: conventional organic, inorganic nanotechnologyc base and the synergy between them when applied to polyethylene considering carbonyl index and UV/VIS results after aging by QUV chamber.


  • IPEN-DOC 23541

    PAREDES, WILBER E.B. ; ANDRADE, DELVONEI ; GERALDO, AUREA . Radioterapia Oncológica: efectos y repercusión en la cavidad bucal. 2017. Saarbrücken: OmniScriptum GmbH & Co. KG. 193 p.


  • IPEN-DOC 23567

    TEOTONIO, ERCULES E.S.; FAUSTINO, WAGNER M.; BRITO, HERMI F.; FELINTO, MARIA C.F.C. ; MOURA, JANDEILSON L.; COSTA, ISRAEL F.; SANTOS, PAULO R.S.. Mechanoluminescence of coordination compounds. In: OLAWALE, DAVID O. (Ed.); OKOLI, OKENWA O.I. (Ed.); FONTENOT, ROSS S. (Ed.); HOLLERMAN, WILLIAM A. (Ed.). Triboluminescence: theory, synthesis, and application. Switzerland: Springer. 2016. p. 39-63.


  • IPEN-DOC 23522

    ALVIM, CARLOS F.; EIDELMAN, FRIDA; MAFRA, OLGA ; FERREIRA, OMAR C.. Energia nuclear em um cenário de trinta anos. Estudos Avançados, v. 21, n. 59, p. 197-220, 2007. DOI: 10.1590/S0103-40142007000100016

    Abstract: A perspectiva da Energia Nuclear no Brasil é analisada sob os aspectos demanda, custos, ambiental, tecnológico e estratégico. A demanda energética projetada, mesmo para crescimentos abaixo dos desejados e considerando algum esforço de redução da intensidade energética, mostra a necessidade de adicionar energia térmica à geração elétrica, hoje predominantemente hídrica. A energia nuclear deve ter participação nessa geração por motivos econômicos, ambientais, tecnológicos e estratégicos.


  • IPEN-DOC 23984

    ALVIM, CARLOS F.; EIDELMAN, FRIDA; MAFRA, OLGA ; FERREIRA, OMAR C.. Nuclear energy over a 30-year scenario. Estudos Avançados, v. 21, n. 59, p. 197-219, 2007. DOI: 10.1590/S0103-40142007000100016

    Abstract: The perspectives of nuclear energy in Brazil is analyzed regarding demand, costs, environmental, technological and strategic aspects. The projected energy demand, even for a growth rate below the desired one and considering some efforts related to energy intensity reduction, shows the need of adding thermal energy to electricity generation, now predominantly hydraulic. Nuclear energy should have a share in this generation due to economical, environmental, technological and strategic reasons.


  • IPEN-DOC 23529

    CARVALHO-OLIVEIRA, REGIANI; AMATO-LOURENÇO, LUIS; MOREIRA, TIANA C.L.; SILVA, DOUGLAS R.R.; VIEIRA, BRUNA D.; MAUAD, THAIS; SAIKI, MITIKO ; SALDIVA, PAULO H.N.. Effectiveness of traffic-related elements in tree bark and pollen abortion rates for assessing air pollution exposure on respiratory mortality rates. Environment International, v. 99, p. 161-169, 2017. DOI: 10.1016/j.envint.2016.09.008

    Abstract: The majority of epidemiological studies correlate the cardiorespiratory effects of air pollution exposure by considering the concentrations of pollutants measured from conventional monitoring networks. The conventional air quality monitoring methods are expensive, and their data are insufficient for providing good spatial resolution. We hypothesized that bioassays using plants could effectively determine pollutant gradients, thus helping to assess the risks associatedwith air pollution exposure. The study regionswere determined fromdifferent prevalent respiratory death distributions in the Sao Paulo municipality. Samples of tree flower buds were collected from twelve sites in four regional districts. The genotoxic effects caused by air pollution were tested through a pollen abortion bioassay. Elements derived from vehicular traffic that accumulated in tree barks were determined using energy-dispersive X-ray fluorescence spectrometry (EDXRF). Mortality data were collected from themortality information program of Sao Paulo City. Principal component analysis (PCA) was applied to the concentrations of elements accumulated in tree barks. Pearson correlation and exponential regression were performed considering the elements, pollen abortion rates and mortality data. PCA identified five factors, of which four represented elements related to vehicular traffic. The elements Al, S, Fe,Mn, Cu, and Zn showed a strong correlationwith mortality rates (R2 N 0.87) and pollen abortion rates (R2 N 0.82). These results demonstrate that tree barks and pollen abortion rates allow for correlations between vehicular traffic emissions and associated outcomes such as genotoxic effects and mortality data.


  • IPEN-DOC 23521

    SUZUKI, LUIS C. ; KATO, ILKA T.; PRATES, RENATO A.; SABINO, CAETANO P. ; YOSHIMURA, TANIA M. ; SILVA, TAMIRES O.; RIBEIRO, MARTHA S. . Glucose modulates antimicrobial photodynamic inactivation ofCandida albicans in biofilms. Photodiagnosis and Photodynamic Therapy, v. 17, p. 173-179, 2017. DOI: 10.1016/j.pdpdt.2016.12.003

    Abstract: Candida albicans biofilm is a main cause of infections associated with medical devices such as catheters,contact lens and artificial joint prosthesis. The current treatment comprises antifungal chemotherapy thatpresents low success rates. Photodynamic inactivation (PDI) involves the combination of a photosensitiz-ing compound (PS) and light to generate oxidative stress that has demonstrated effective antimicrobialactivity against a broad-spectrum of pathogens, including C. albicans. This fungus senses glucose induc-ing an upregulation of membrane transporters that can facilitate PS uptake into the cell. The aim ofthis study was to evaluate the effects of glucose on methylene blue (MB) uptake and its influence onPDI efficiency when combined to a red LED with central wavelength at = 660 nm. C. albicans biofilmswere grown on hydrogel disks. Prior to PDI assays, MB uptake tests were performed with and withoutglucose-sensitization. In this system, the optimum PS administration was determined as 500 M of MBin contact with the biofilm during 30 min before irradiation. Irradiation was performed during 3, 6, 9, 12,15 and 18 min with irradiance of 127.3 mW/cm2. Our results showed that glucose was able to increaseMB uptake in C. albicans cells. In addition, PDI without glucose showed a higher viability reduction until6 min; after 9 min, glucose group demonstrated a significant decrease in cell viability when compared toglucose-free group. Taken together, our data suggest that glucose is capable to enhance MB uptake andmodulate photodynamic inactivation of C. albicans biofilm.


  • IPEN-DOC 23987

    ALMEIDA, THALLIS L.; QUEIROZ, FERNANDA M. ; TERADA, MAYSA; COSTA, ISOLDA ; CAPELOSSI, VERA R.. On the effects of hydrothermal treatments on the corrosion resistance of the TSA anodized AA7475-T761 alloy. Key Engineering Materials, v. 710, p. 169-174, 2016. DOI: 10.4028/www.scientific.net/KEM.710.169

    Abstract: The effect of hydrothermal treatment time on sealing and corrosion resistance of the AA7475-T761 anodized aluminium alloy has been investigated in this study. The hydrothermal treatments tested are environmental compatible without chromium ions involved. Anodizing was carried out by a tartaric-sulphuric anodizing (TSA) process and this was followed by hydrothermal treatments for partial sealing, in various solutions. The effect of propyleneglycol (PRG) and/or cerium ions in the hydrothermal treatment solution was evaluated. Four treatment times were tested, specifically, 2.5, 5.0, 7.5 and 10 min. The corrosion resistance of the anodized and treated samples was evaluated by Electrochemical Impedance Spectroscopy (EIS) and the anodic layers formed were characterized by Scanning Electron Microscopy (SEM). The EIS results showed that the hydrothermal treatments in solutions with cerium ions resulted in similar impedances for periods of treatment from 5 to 10 min whereas in the solutions with PRG the impedance increased with time of treatment from 2.5 to 10 min showing a slower kinetics of anodic layer sealing. However, the fastest kinetics of sealing were associated to the treatments that combined two steps, one in PRG and other in cerium containing solutions with similar impedances obtained from 2.5 to 10 min of treatment. Surface evaluation by SEM showed that the porosities in the anodic layer were not sealed for the periods of hydrothermal treatments corresponding to 2.5 min. The presence of cerium in hydrothermal treatment had a beneficial effect on the stability of the anodic layer formed and provided a healing effect on the corroding sites.


  • IPEN-DOC 23983

    SILVA, D.L.C.; KASSAB, L.R.P.; MARTINELLI, J.R. ; SANTOS, A.D.; PILLIS, M.F. . Production and characterization of carbon thin films by the magnetron sputtering technique. Materials Science Forum, v. 881, p. 471-474, 2017. DOI: 10.4028/www.scientific.net/MSF.881.471

    Abstract: Carbon thin films were produced by the magnetron sputtering technique. The deposition of the carbon films was performed on Co buffer-layers previously deposited on c-plane (0001) sapphire substrates. The samples were thermally treated under vacuum conditions and characterized by Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD peak related to the carbon film was observed and the Raman spectroscopy indicated a good degree of crystallinity of the carbon film.


  • IPEN-DOC 23988

    AWADALLAH, AMNA K.E.; OSMAN, MAKARIM E.M.; IBRAHIM, MARIAM A.; BERNARDES, EMERSON S. ; DIAS-BARUFFI, MARCELO; KONOZY, EMADELDIN H.E.. Isolation and partial characterization of 3 nontoxic D‐galactose– specific isolectins from seeds of Momordica balsamina. Journal of Molecular Recognition, v. 30, n. 2, p. 1-12, 2016. DOI: 10.1002/jmr.2582

    Abstract: Three isolectins denoted hereforth MBaL‐30, MBaL‐60, and MBaL‐80 were isolated from seeds extract of Momordica balsamina by 30%, 60%, and 80% ammonium sulfate saturations, respectively. The native molecular weights of these lectins, as judged by gel filtration, were 108, 56, and 160 kDa, respectively. On SDS‐PAGE, under reduced condition, 27 kDa band was obtained for all isolectins. The lectins hemagglutinating activities were variably inhibited by D‐galactose (minimum inhibitory concentrations = 12.5mM, 50mM, and 0.391mM, respectively). MBaL‐30 and ‐60 could agglutinate all human blood types with slight preference for the A and O blood groups, whereas MBaL‐80 did not agglutinate B and AB blood types. The 3 isolectins were purified from crude seeds extract, collectively, in a single step on the affinity matrix Lactamyl‐Seralose 4B; this purified lectin fraction, which contains all isolectins, is termed MBaL. The N‐terminal of MBaL till the 25th amino acid was NLSLSELDFSADTYKSFIKNLRKQL, which shares 88% sequence identity with Momordica charantia lectin type‐2 ribosomal inactivating protein from Momordica charantia and 50% with momordin II from Momordica balsamina. MBaL retained 100% activity at up to 50°C for 30 minutes. MBaL‐30 and MBaL‐60 exhibited maximum activities in the pH range between 4 and 8, while MBaL‐80 was showing maximum activity in the pH range between 3 and 5. Treatment of MBaL‐30 and MBaL‐60 with EDTA completely abolished their hemagglutinating activities. Addition of Zn and Fe ions to the ethylenediaminetetraacetic acid– treated MBaL‐30 and MBaL‐60 lectins did not only regained the loss of activity but also resulted in 200% to 300% increase in activity, respectively. MBaL‐30 and ‐60 agglutinated gram positive Listeria monocytogenes and Staphylococcus aureus, whereas MBaL‐30 could merely agglutinate Escherichia coli. None of these lectins could arrest bacterial growth. Addition of MBaL to cancer cell lines (Gastric cancer cell line (AGS) and Gastric cencer cell line (MKN45), Glioblastoma (ECV‐304), and Human urinary bladder cancer cell line (U87‐MG)) at varying concentrations did not cause statistically significant changes on cell growth and viability.


  • IPEN-DOC 23991

    MIRANDA, FABIO; RODRIGUES, DANIEL; NAKAMOTO, FRANCISCO Y.; FRAJUCA, CARLOS; SANTOS, GIVANILDO A. dos; COUTO, ANTONIO A. . Microstructural evolution of composite 8 WC-(Co, Ni): effect of the addition of SiC. Defect and Diffusion Forum, v. 371, p. 78-85, 2016. DOI: 10.4028/www.scientific.net/DDF.371.78

    Abstract: Tungsten carbide (WC) based cemented carbides, also called hardmetals, are a family of composite materials consisting of carbide ceramic particles embedded in a metallic binder. They are classified as metal matrix composites (MMCs) because the metallic binder is the matrix that holds the bulk material together [1]. WC based composites are used in applications where a good combination of hardness and toughness are necessary [2]. It is usual to add more components to tailor the microstructure of the WC-(Co, Ni) system. The hardness for the cemented carbides based on nickel, increases significantly because of the addition of reinforcements like SiC nano-whisker [3]. In this work, the SiC was considered as an additional component for the composite WC-8(Co, Ni). Four mixtures were prepared with SiC contents ranging from 0 to 3.0 wt%. These mixtures were pressed (200 MPa) and green samples with 25.2 mm of diameter and 40 g were produced. Sintering was carried out in Sinter-HIP furnace (20 bar). Two sintering temperatures were investigated, i.e. 1380 and 1420ºC, and the sintering time considered was 60 minutes. The relative density, hardness, linear and volumetric shrinkage were determined. Microstructural evaluation was investigated by optical microscopy and scanning electron microscopy (SEM-FEG). The results showed that the addition of SiC promoted higher densification and grain size growth. The hardness was higher for samples with SiC, so solid solution hardening of the binder was more effective than WC grain size growth.


  • IPEN-DOC 23960

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; OTUBO, JORGE. An in situ high-temperature x-ray diffraction study of phase transformations in maraging 300 steel. Defect and Diffusion Forum, v. 371, p. 73-77, 2016. DOI: 10.4028/www.scientific.net/DDF.371.73

    Abstract: An in situ high-temperature X-ray diffraction (HTXRD) study in maraging 300 steel was carried out to study the martensite to austenite transformation and effect of time of exposure in the austenite reversion below austenite start temperature. Solution annealed materials were subjected to controlled heating-holding cycles. The first sample was heated at a rate of 10 ºC/min from room temperature to 800 ºC, showing that the microstructure is completely martensitic (α’110) until 600 ºC. From 650 ºC until 800 ºC, the microstructure is gradually changing from martensitic to austenitic, showed by the increasing peaks of γ111 and reducing peaks of α’110. At 800 ºC the microstructure is completely austenitic (γ111). Another sample was heated at 10 ºC/min from room temperature to 600 ºC and held for 4 hours. At 600 ºC, at 0 h time of exposure, only a martensitic peak was observed. An austenite peak can be observed after some time of exposure at this temperature. The volume fraction of austenite increased with increasing time of exposure at 600 ºC, reaching 50/50 volume fraction after 4 hours of exposure. XRD diffraction patterns for the same sample that was held for 4 hours at 600 ºC and then cooled down in air to room temperature showed the same intensity of austenite and martensitic peaks found in situ at 600 ºC for 4 hours (retained austenite), with the volume fraction of 50/50 of austenite and martensite phases. The HTXRD technique can be used to identify and quantify martensite to austenite transformation and austenite retention.


  • IPEN-DOC 23961

    SILVA, J.O. ; CALDAS, L.V.E. . Assessment of dosimetric parameters in mammography employing a homemade ionization chamber / Estimativa de parâmetros dosimétricos em mamografia utilizando uma câmara de ionização caseira. Scientia Plena, v. 12, n. 12, p. 1-11, 2016. DOI: 10.14808/sci.plena.2016.124101

    Abstract: X-ray mammography examination is the reference tool to discover breast cancer in an early stage. The mammography unit must follow an accurate quality control program that covers both patient and staff radiation protection. Plane parallel ionization chambers are the reference instrument for dosimetry in mammography beams, but they can represent higher cost for small clinics in countries as Brazil. In this work, it is presented a low cost ionization chamber for mammography X-rays energy range dosimetry developed at IPEN. The homemade ionization chamber has a sensitive volume of 6.0 cm3 and it was utilized to execute quality control tests in two distinct mammography systems: a GE Senographe DMR-plus and a Philips VMI Graph Mammo. The setups for the tests performed agreed with the IAEA HHS 2 and 17 recommendations. A breast phantom of various PMMA thicknesses was utilized in this work. The homemade ionization chamber performance was compared to that of a commercial one. The maximum difference between the incident air kerma measured with the reference ionization chamber and the developed one was only 5.62% for the GE equipment and only 4.42% for the Philips equipment. The homemade ionization chamber presented an excellent performance in incident air kerma and HVL measurements for the radiographic techniques utilized in the present work. All the results obtained were within IAEA specifications.


  • IPEN-DOC 23969

    ALVAREZ, R.H.; NATAL, F.L.N.; ALMEIDA, B.E. ; OLIVEIRA, J.E. ; BARTOLINI, P. ; MELO, A.J.F.; DUARTE, K.M.R.; RIBELA, M.T.C. . Effect of cold stress on physicochemical characteristics and biological activity of equine chorionic gonadotropin. Animal Reproduction, v. 13, n. 4, p. 750-755, 2016. DOI: 10.21451/1984-3143-AR781

    Abstract: The purpose of this study was to evaluate if freezing-thawing and cooling processes affect the structural properties and biological activity of commercial equine chorionic gonadotropin (eCG). First, the structure profile of diluted eCG underwent none, one or three cycles of freezing-thawing was analysed by reverse phase high-performance liquid chromatography (RP-HPLC). In a second experiment, groups of prepuberal rats were treated with sterile water for injection USP or eCG that underwent none, one or three cycles of freezing-thawing to assess the increase of ovarian weigh. Finally, groups of prepubertal gilts were treated with diluted eCG immediately after reconstitution (T1), after refrigeration for six months (T2) and after freezing and subsequently thawing for one (T3) or three (T4) cycles. The control group (T5) received sterile water for injection USP without eCG. Ovulation was induced with human chorionic gonadotropin (hCG), administered 72 h after the eCG. Gilts were slaughtered five days after the hCG injection and ovaries were recovered and analysed for the presence of corpora lutea. Data were analysed by ANOVA and Fisher’s exact tests. In the analyses by RP-HPLC, the retention times of cold stressed eCG were similar to unstressed control. The mean ovarian weight of rats treated with cold stressed and unstressed eCG was statistically higher than water control (P < 0.05). Lastly, significantly more gilts ovulated in groups T1, T2, T3 and T4 than in the control T5 (P < 0.05). It was concluded that freezing-thawing, as well as cooling over a period of up to six months, did not significantly change the structural properties or biological activity of eCG.


  • IPEN-DOC 23561

    KINOSHITA, ANGELA; GHILARDI, ALINE M.; FERNANDES, MARCELO A.; FIGUEIREDO, ANA M.G. ; BAFFA, OSWALDO. Electron spin resonance dating of toxodon tooth from upper Ribeira Valley, São Paulo, Brazil. Radiation Protection Dosimetry, v. 172, p. 296-301, 2016. DOI: 10.1093/rpd/ncw195

    Abstract: Electron spin resonance (ESR) dating was applied to date a sample of fossil tooth found in Ribeira Valley, São Paulo, Brazil. This region is characterized by abundant fossil records of Pleistocene–Holocene South American megafauna belonging to different faunistic moments related to climate changes during the quaternary. As the number of fossils dated is not too large, the dating of materials from this region will provide important information to better understand the events associated with the presence and extinction of these species. The equivalent dose (De) was determined using single exponential fitting resulting in (24 ± 1)Gy. The De was converted to age using ROSY ESR Dating program and the concentration of radioisotopes present in the sample and soil determined through neutron activation analysis. The ages cover the range of 25–34 ka. This information is important to contextualize other findings in the region from different sites and to help obtain better information about the climate changes in this region.


  • IPEN-DOC 23959

    MENZEL, FRANCINE ; SABUNDJIAN, GAIANE ; DAURIA, FRANCESCO; MADEIRA, ALZIRA A.. Proposal for systematic application of BEPU in the licensing process of nuclear power plants. International Journal of Nuclear Energy Science and Technology, v. 10, n. 4, p. 323-337, 2016.

    Abstract: In general, Best Estimate Plus Uncertainty (BEPU) methodology implies application of ‘realistic’ or the so-called ‘best estimate’ computational codes with uncertainty quantification to the thermal-hydraulic safety analyses of nuclear power plants within the licensing process. The results of such analyses are documented in Chapter 15 of Final Safety Analysis Report (FSAR). The objective of the present work is to discuss the possibility of adopting BEPU methodology to the entire FSAR, therefore extending its application range to the other chapters. To perform an entire FSAR based on BEPU, a homogenisation of the analysis is proposed. The first step towards BEPU-FSAR requires identification and characterisation of the parts where numerical analyses are needed (the so-called BEPU topics). The next step is to create a list of key technological areas, the so-called key disciplines and their related key topics and then an overview of the currently computational activities in each technological area. Based on the finalised BEPU applications one can conclude that this methodology is feasible, which encourages to extended its range of use to the other technological areas of FSAR, and therefore to demonstrate the industrial worth and interest. The future step of this work will mainly be focused on the propagation of this expertise into the remaining technical areas of FSAR, adding new knowledge and therefore creating coherent and rigorous background of the BEPU-FSAR methodology.


  • IPEN-DOC 23539

    RIGHI, SERENA; VERITA, SIMONA; ROSSI, PIER L.; MADUAR, MARCELO F. . A dose calculation model application for indoor exposure to two-layerwalls gamma irradiation: the case studyof ceramic tiles. Radiation Protection Dosimetry, v. 171, n. 4, p. 545-553, 2016. DOI: 10.1093/rpd/ncv476

    Abstract: A calculation model for determining the indoor dose due to building materials with significant concentration of radioactivity has been applied to the case study of ceramic tiles; the model allows the contribution of bearing walls and wall covering materials to be calculated. The model is implemented in FORTRAN 77 and provides a quantification of the gamma radiation field (in terms of external dose rate in air, nGyh21) inside a room with known dimensions. Application model results have been validated both by comparison with the results obtained by other authors and by experimental measurements. Model sensitivity and performances have been analysed and lastly the case studies focused on ceramic tiles have been proposed.


  • IPEN-DOC 23966

    COSTA, WANDERLEY da; SOUZA, EDITH M.M.; SILVA, LEONARDO G.A. ; WIEBECK, HELIO. Behavior of adhesion forces of the aqueous-based polyurethane adhesive magnetically conditioned. Modern Chemistry & Applications, v. 4, n. 4, p. 1-8, 2016. DOI: 10.4172/2329-6798.1000190

    Abstract: This research presents a new proposal to water based adhesives manufacturing process, utilizing magnetic conditioning. Using this technique it is possible to increase the adhesion capacity between the adhesive and the substrate. The formulation proved to be efficient after the magnetic conditioning and without reactivation which also generated a significant alteration of the viscosity which was 350 mPa.s to 1100 mPa.s, without the necessity of the addition of any other product as thickener. If we compare the same adhesive formulation, with magnetic conditioning and without reactivation and an adhesive without magnetic conditioning and with reactivation, the increase of adhesion capacity was 42.11%, in the magnetically conditioning. When we verify the shear stresses in adhesive without reactivation, without magnetic conditioning and irradiated at 15 kGy we found an average of 3.29 × 105 Pa in the shear stresses, that is 2.16 times lower, compared with the average value found in the test specimens, magnetically conditioned, without reactivation, which was 7.11 × 105 Pa. If the non-ionizing radiation dose of 25 kGy passes, the shear stresses decrease considerably, regardless of the process, with or without magnetic conditioning has the consequence of breaking of the bonds of the polymeric matrix with the test specimens interface.


  • IPEN-DOC 23973

    BALDOCHI, S.L. ; MORATO, S.P. . Fluoride bulk crystals growth. In: HASHMI, SALEEM (Ed.). Reference Module in Materials Science and Materials Engineering. Oxford: Elsevier. 2016. p. 1-6.

    Abstract: Fluoride crystals have long presented a challenge for chemists and physicists, because their preparation often requires very specific procedures. Their synthesis usually requires the use of toxic and/or corrosive materials, procedures demanding suitable equipment, and safety operational norms. Additionally, most of the fluoride compounds are moisture sensitive. As a result, a dry working environment is needed. In spite of this, fluoride crystals have found many applications as dosimeters, information storage devices, X-ray monochromators, and, in particular, in the field of optics as laser hosts and other components such as windows, which has encouraged the development of research work on the preparation of large crystals. The successful preparation of bulk fluoride crystals is dependent upon a number of factors directly related to the crystal growth conditions of the most important is the purity of the raw material. The choice of high purity commercial salts will not always assure the growth of a crystal with high quality. First, the manipulation of fluorides without the correct procedures can easily introduce moisture contamination. Fluorides are very sensitive to water and oxygen, which are always present in the work environment. Second, commercial fluorides are rarely of sufficient purity, with respect to oxygen contaminants. Usually, starting materials are ‘five-nines’ (99.999%) pure with respect to the cation. Oxygen-related impurities, such as OH , COH , NO2 , present vibrational modes in the infrared range. Their presence, even in small concentrations, can be detrimental to the quality of infrared optical devices. In general, most simple fluoride crystals, such as alkali halides (LiF, NaF, RbF) or alkaline-earth fluorides (CaF2, SrF2, BaF2), are grown directly from commercial chemicals, after a preliminary treatment to eliminate moisture and oxygen contaminants. However, more complex fluoride compounds (e.g., LiSrAlF6 or BaY2F8) need to be carefully synthesized before the growth process. A preliminary treatment or synthesis of the raw material to be used for the crystal preparation is the first step in the growth of fluoride crystals.


  • IPEN-DOC 23968

    CUNHA, CECILIO A. ; CORREA, OLANDIR V. ; SAYEG, ISSAC J.; LIMA, NELSON B. ; RAMANATHAN, LALGUDI V. . Structural and thermodynamic properties of nanocrystalline Cr3C2-25(Ni20Cr) composite powders produced by high-energy ball milling. Journal of Thermal Analysis and Calorimetry, v. 126, n. 3, p. 1447-1453, 2016. DOI: 10.1007/s10973-016-5735-9

    Abstract: Nanostructured coatings have been used to protect components exposed to severe service conditions. High energy milling is widely used to produce nanocrystalline feedstock of coating materials such as chromium carbide and tungsten carbide. This paper presents the structural and thermodynamic properties of Cr3C2-25(Ni20Cr) powders that were high energy milled for different times. During the high energy milling of Cr3C2-25(Ni20Cr) powder, severe plastic deformation takes place. A small part of the energy spent in this process is stored in the crystal lattice as deformation energy. The crystallite size and microstrain in nanocrystalline Cr3C2-25(Ni20Cr) powders milled for different times were determined by X-ray diffraction measurements. Differential scanning calorimetric (DSC) studies of the milled powders revealed a broad transformation, characteristic of a large exothermic reaction in the nanostructured powder. The enthalpy variation measured by DSC permitted determination of the deformation energy stored in the Cr3C2-25(Ni20Cr) powders milled for different times. These measurements also enabled calculation of the specific heat variation of the milled powders.


  • IPEN-DOC 23967

    SOUZA, L.F.; SILVA, A.M.B.; ANTONIO, P.L. ; CALDAS, L.V.E. ; SOUZA, S.O.; DERRICO, F.; SOUZA, D.N.. Dosimetric properties of MgB4O7:Dy,Li and MgB4O7:Ce,Li for optically stimulated luminescence applications. Radiation Measurements, v. xx, n. xx, p. 1-4, 2017. DOI: 10.1016/j.radmeas.2017.02.009

    Abstract: The present work describes the optically stimulated luminescence (OSL) of a tissue equivalent crystal, the magnesium tetraborate, doped with dysprosium or cerium and co-doped with lithium due to the lack of materials with characteristics suitable for several dosimetric applications. In the present work, MgB4O7:Dy,Li and MgB4O7:Ce,Li were characterized through their OSL and radioluminescence emissions. Our results indicate that MgB4O7:Ce,Li has a strong emission peaked at 420 nm that is connected to the Ce3+ electronic transitions, while the emission of MgB4O7:Dy,Li has several peaks connected to the Dy3+ transitions. The OSL decay curves from both materials are composed by two components: a slow one and a fast one. MgB4O7:Ce,Li is 10 times more sensitive than MgB4O7:Dy,Li, especially due to the wavelengths of the emission peaks. The dose response for both materials were sublinear from 0.2 Gy to 100 Gy, for MgB4O7:Ce,Li, and from 0.2 Gy to 40 Gy, for the MgB4O7:Dy,Li. The OSL signal from MgB4O7:Ce,Li showed good stability over 40 days (with a fading < 1%), while MgB4O7:Dy,Li presented a complete fading of the signal after 40 days. These results suggest a clear potential of MgB4O7:Ce,Li for radiation dosimetry purposes using OSL technique.


  • IPEN-DOC 23970

    ARAUJO, JULIANO A.; SOUZA, ROBERTO M.; LIMA, NELSON B. de ; TSCHIPTSCHIN, ANDRE P.. Thick CrN/NbN multilayer coating deposited by cathodic arc technique. Materials Research, v. 20, n. 1, p. 200-209, 2017. DOI: 10.1590/1980-5373-MR-2016-0293

    Abstract: The production of tribological nanoscale multilayer CrN/NbN coatings up to 6 μm thick by Sputtering/HIPIMS has been reported in literature. However, high demanding applications, such as internal combustion engine parts, need thicker coatings (>30 μm). The production of such parts by sputtering would be economically restrictive due to low deposition rates. In this work, nanoscale multilayer CrN/NbN coatings were produced in a high-deposition rate, industrial-size, Cathodic Arc Physical Vapor Deposition (ARC-PVD) chamber, containing three cathodes in alternate positions (Cr/ Nb/Cr). Four 30 μm thick NbN/CrN multilayer coatings with different periodicities (20, 10, 7.5 and 4 nm) were produced. The coatings were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The multilayer coating system was composed of alternate cubic rocksalt CrN and NbN layers, coherently strained due to lattice mismatch. The film grew with columnar morphology through the entire stratified structure. The periodicities adopted were maintained throughout the entire coating. The 20 nm periodicity coating showed separate NbN and CrN peaks in the XRD patterns, while for the lower periodicity (≤10nm) coatings, just one intermediate lattice (d-spacing) was detected. An almost linear increase of hardness with decreasing bilayer period indicates that interfacial effects can dominate the hardening mechanisms.


  • IPEN-DOC 22109

    MACHADO, LEANDRO M. ; ROSSI, WAGNER de . Medida do limiar de ablação do GaSb, GaAs, InSb e Si para pulsos ultracurtos. In: PROGRAMA INSTITUCIONAL DE BOLSAS DE INICIAÇÃO CIENTÍFICA, 13.; PROGRAMA DE BOLSAS E INICIAÇÃO CIENTÍFICA CNEN, 4., 29-30 de agosto, 2007, São Paulo, SP. Resumo expandido...

    Palavras-Chave: ablation; gallium antimonides; gallium arsenides; indium antimonides; silicon; pulses


  • IPEN-DOC 22773

    VELO, A.F. ; HAMADA, M.M. ; CARVALHO, D.V.S. ; MARTINS, J.F.T.; MESQUITA, C.H. . A portable tomography system with seventy detectors and five gamma-ray sources in fan beam geometry simulated by Monte Carlo method. Flow Measurement and Instrumentation, v. 53, p. 89-94, 2017. DOI: 10.1016/j.flowmeasinst.2016.09.015

    Abstract: This paper describes the Monte Carlo simulation, using MCNP4C, of a portable instant non-scanning tomography containing five radioactive sources with the same activities and seventy NaI(Tl) detectors constituted of five sets of fourteen detectors, diametrically opposite to each radioactive source. The detector was validated by comparison with the experimental measurements. The full width at half maximum (FWHM) deviation between the experimental and the simulated spectra was 3.5%. A steel pipe of 17 cm×0.5 cm (diameter×thickness) containing water and two dynamic bubbles of 2 cm and 4 cm diameter were simulated. The SIRT algorithm was used to reconstruct the images. The simulated images are presented in frames. On the first frame, no bubble is observed. On the subsequent frames, the growing of the bubbles is observed, reaching the maximum diameter; after that, the bubble begins to decrease progressively, until its disappearance. The measured bubble diameters generated by simulation were 43 ± 3 mm and 27 ± 2 mm for the bubbles of 40 mm and 20 mm diameters, respectively. The spatial resolution of the proposed simulated tomography was estimated by the Modulation Transfer Function (MTF), presenting a spatial resolution of 18.3 mm and 20.2 mm for samplings at 137Cs photopeak and full window, respectively.

    Palavras-Chave: monte carlo method; tomography; portable equipment; industrial plants; images; simulation


  • IPEN-DOC 22746

    SILVA, JOSE E.R. da ; JUNQUEIRA, FERNANDO de C. ; LIMA, JOSE R. de . Projeto mecânico do elemento combustível tipo placa do reator IPEN/MB-01. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Maio, 2016. (IPEN-CEN-PSE-RMB-005-00-RELT-001-00). Restrito.

    Título do projeto: RMB

    Palavras-Chave: progress report; fuel elements; ipen-mb-1 reactor; fuel plates; specifications


  • IPEN-DOC 22735

    KURAZUMI, EDUARDO P. ; RIBEIRO, MARIA A.M. . Especificação funcional do sistema computacional para avaliação do ativo isotópico. São Paulo: Instituto de Pesquisas Energéticas e Nucleares - CEN, Dezembro, 2016. (IPEN-CEN-P&D-ETN-196-00-RELT-003-00). Restrito.

    Título do projeto: Ativo Isotópico

    Palavras-Chave: radioactive wastes; specifications; angra-1 reactor; angra-2 reactor; progress report


  • IPEN-DOC 21634


    Palavras-Chave: calibration; liquid scintillators; sulfur 35; comparative evaluations; activity meters


  • IPEN-DOC 23971

    ANTUNES, R.A.; OLIVEIRA, M.C.L. de; SOUZA, J.A.B. de . Effect of temperature on corrosion and semiconducting properties of oxide films formed on M5 zirconium alloy. Corrosion Engineering, Science and Technology, v. 51, n. 2, p. 104-109, 2016. DOI: 10.1179/1743278215Y.0000000036

    Abstract: Nuclear fuel cladding for pressurised water reactors is commonly manufactured with zirconium alloys. The M5 alloy is a relatively new cladding material for in-reactor used with enhanced performance compared to traditional zircaloys. In this work, the influence of temperature on the corrosion resistance and semiconducting properties of the passive film formed on the M5 alloy in a borate buffer solution has been evaluated. The electrochemical behaviour of the zirconium alloy was assessed by potentiodynamic polarisation tests, electrochemical impedance spectroscopy and Mott–Schottky plots. The results indicated that the corrosion resistance of the M5 alloy decreased with temperature due to the formation of a less stable and more defective passive film. The Mott–Schottky approach used in combination with polarisation tests and impedance measurements was effective to reveal the protective state of the passive film on the M5 alloy.


  • IPEN-DOC 23977

    FURIGO, ISADORA C.; SUZUKI, MIRIAM F. ; PEDROSO, JOAO A.B.; RAMOS-LOBO, ANGELA M.; ALENCAR, AMANDA; BUONFIGLIO, DANIELLA C.; TEIXEIRA, PRYSCILA D.; ZAMPIERI, THAIS T.; OREFICE, GABRIEL; OLIVEIRA, JOAO E.O.; BARTOLINI, PAOLO ; SOARES, CARLOS R.J. ; DONATO JUNIOR, JOSE. Role of prolactin in the anti-diabetic effects of bromocriptine: possible action through estrogen receptor alpha in the brain. In: PROF. ERIC A. NEWSHOLME RESEARCH SYMPOSIUM. METABOLIC REGULATION, 3rd, 14 de julho, 2016, São Paulo, SP. Abstract... São Paulo: ICB/USP. p. 84.

    Abstract: The quick release bromocriptine mesylate (Cycloset®) was recently approved as a drug to treat type 2 diabetes mellitus, but the exact mechanism of action of this drug remains unknown. Aims: We hypothesized that the anti-diabetic effects of bromocriptine is due to reductions in basal prolactin levels. Furthermore, these effects could be mediated by an interaction with estrogen receptor α (ERα) in the brain. Methodology: Initially, we studied 4 groups of obese and diabetic (ob/ob) mice for 16 days: 1) control; 2) prolactin (micro-osmotic pumps infusing prolactin; 18 μg/day); 3) bromocriptine (one daily ip injection of bromocriptine mesylate; 12 μg/g); and 4) bromocriptine + prolactin. Results: No changes in food intake were observed among the groups; however, bromocriptine groups showed a reduced weight gain along the experiment. Prolactin replacement prevented the improvement in glucose tolerance, insulin sensitivity and serum insulin levels caused by bromocriptine treatment. In another experiment, we found that ERα mRNA showed a very high co-expression with prolactin-responsive cells in hypothalamic nuclei involved in the regulation of glucose homeostasis, such as the arcuate and ventromedial nuclei. Conclusion: Our results suggest that changes in basal prolactin levels are at least partially responsible for the anti-diabetic effects of bromocriptine. These effects are possibly mediated by a crosstalk between prolactin and ERα signaling in the brain. Our findings revealed a novel mechanism that could be target of drugs to prevent and treat diabetes mellitus.


  • IPEN-DOC 23972

    SANTOS, VINICIUS J. ; ZAFALON, ANGELICA T.; LUGAO, ADEMAR B. ; PARRA, DUCLERC F. . Influence of dispersion process on the characteristics of PVP-CLAY hydrogel. In: BRAZILIAN CONFERENCE ON COMPOSITE MATERIALS, 3rd, 28-31 de agosto, 2016, Gramado, RS. Proceedings... .

    Abstract: Hydrogel is a hydrophilic material and can be used as wound dressing, since it can be biocompatible, potencial drug delivery system and absorbent of fluids. Hydrogels can be produced by one or more hydrophilic polymers; natural or synthetic. These materials have a three-dimensional network of cross-linked polymer chains, and may be synthetized by gamma radiation that crosslinks and sterilizes the hydrogel, in one step. PVP-clays composites show, through many ways of swellings tests, an increase of fluid absorption properties. These properties can be modified when using a mechanical or sonication dispersion process of clay in water, before polymer mixture preparation. The aim of the present study is to prepare a hydrogel with PVP-clay containing poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), Agar and Laponite clay processed by gamma radiation. The influence of clay dispersion process, clay/polymer ratio in the hydrogel and type of sample (dried or not) were investigate according to the methodology of gel fraction, swelling tests, Scanning electronic microscopy (SEM). According to the results of water swelling, the clay sonication process is more effective than mechanical dispersion, however, if the sample was dried in stove before the swelling test, the results were similar, probable owing to morphology modification promoted by the stove drying process.


  • IPEN-DOC 23979

    DIAS, M.C.F.; MUCCILLO, E.N.S. . Effects of TiO2 addition on microstructure and ionic conductivity of gadolinia-doped ceria solid electrolyte. In: BANSAL, NAROTTAM P. (Ed.); KUSNEZOFF, MIHAILS (Ed.); SHIMAMURA, KIYOSHI (Ed.) INTERNATIONAL CONFERENCE ON ADVANCED CERAMICS AND COMPOSITES, 39th, January 25-30, 2015, Daytona Beach Florida, USA. Proceedings... Hoboken, NJ, USA: John Wiley & Sons, Inc.. p. 1-9.

    Abstract: Ceria containing trivalent rare-earth is a solid electrolyte with higher ionic conductivity than the yttria fully-stabilized zirconia standard ionic conductor. This feature turns these ceria-based ionic conductors promising materials for application in solid oxide fuel cells operating at intermediate temperatures (500–700ºC). One of the most utilized approaches to optimize the electrical conductivity and other properties of these materials is the introduction of a second additive, which could change the specific properties of cerium dioxide. Subsequently, in this work, ceria-20 mol% gadolinia with additions of TiO2 is prepared using solid state reaction. The main purpose is to investigate the effects of the additive on densification, microstructure and electrical conductivity of the solid electrolyte. Sintered pellets are characterized by evaluating apparent density, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and electrical conductivity by impedance spectroscopy. It was found that the small additions of titanium oxide improved the densification and turned negligible the porosity of sintered gadolinia-doped ceria specimens. This additive promotes increase of the blocking of charge carriers at the grain boundaries due to solute exsolution and formation of the pyrochlore Gd2Ti2O7 phase at grain boundaries for contents in excess of the solubility limit.


  • IPEN-DOC 23992

    MERGULHAO, M.V. ; PODESTA, C.E.; NEVES, M.D.M. das . Mechanical and microstructural evaluation of CoCr alloys manufactured via selective laser melting (SLM). In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Proceedings... .

    Abstract: Dental prosthesis components are widely produced with CoCr alloys. New near net shape techniques has been used nowadays as an alternative route. The aim of this study was evaluated the mechanical properties and the microstructural characterization of CoCr dental alloys manufactured by SLM and to investigated the correlation of chemical composition between mechanical properties of standard specimens. The tensile specimens was manufactured by SLM technique in standard dimensions by two different composition of CoCr dental alloy and were chemical analyzed using scanning electron microscope with energy-dispersed X-ray spectroscopy (SEM-EDS) and X-ray fluorescence. The mechanical properties as uniaxial tensile (yield strength, maximum tensile, rupture tensile, elongation and elastic modulus) and Vickers hardness were evaluated. The microstructure of the samples were characterized using optical microscope (OM) and SEM-EDS. The mechanical results indicate higher values for both composition of CoCr alloys fabricated via SLM technique. The micrographs revealed a characteristic morphology of layer used in the SLM technique. Keywords: CoCr alloys, selective laser melting, biomaterial, dental prothesis.


  • IPEN-DOC 23687

    MONTEIRO, K.N.; CORREIA, Y.P.; GENOVA, L.A. ; CESAR, P.F.. Effect of shade and ageing on strength of translucent Y-TZP. Dental Materials, v. 32, p. e9-e10, 2016. DOI: 10.1016/j.dental.2016.08.019


  • IPEN-DOC 23686

    BOARO, L.; CAMPOS, L.M. ; VARCA, G.H.C. ; MARQUES, P.A.; PIMENTEL, A.C.; ROMAN-TORRES, C.V.; BRANDT, W.C.; COGO-MULLER, K.; BRAGA, R.R.; PARRA, D.F. . BisGMA/TEGDMA based material with antibacterial activity. Dental Materials, v. 32, p. e8-e9, 2016. DOI: 10.1016/j.dental.2016.08.016


  • IPEN-DOC 23685

    CAMPOS, L.M.P. ; BOARO, L.C.C.; SANTOS, T.M.R.; VARCA, G.H.C. ; PARRA, D.F. . Estudo da Liberação de Clorexidina Incorporada em Nanopartículas de Montmorilonita em Compósitos a Base de BisGMA/TEGDMA. In: SBPQO ANNUAL MEETING, 33rd, 07-10 de setembro, 2016, Campinas, SP. Resumo... .

    Abstract: O objetivo desse estudo foi desenvolver nanocompósitos experimentais adicionados com nanopartículas de Montmorilonita (MMT) incorporadas com diacetato de clorexidina (CHX) como carga, em uma matriz polimérica a base de BisGMA/TEGDMA (1:1). Foram confeccionados compósitos experimentais (n=5) adicionados com carga nas concentrações de 0.01, 0.5, 2 e 10% em massa (p/p). A liberação da CHX foi avaliada in vitro em uma solução neutra (pH 7, 50mm) a 37 oC, por 366 horas. A quantificação de CHX foi avaliada por espectrofotometria de UV (ʎ=255 nm). A formação de nanocompósitos foi avaliada por meio das metodologias Microscopia Eletrônica de Transmissão (MET) e Difração de RaioX (DRX). Foi observada uma liberação de fármaco constante em todos os grupos analisados, de 0 a 366 horas. Ao atingir 366 horas, o grupo adicionado com 0,01% de carga apresentou 0.126 g.L1 de liberação de CHX, o grupo com 0.5% apresentou 0.139 g.L1, o grupo com 2% apresentou 0.150 g.L1 e o grupo com 10% apresentou 0.151 g.L1. Observouse por meio do DRX e MET que houve intercalação entre a MMT (adicionada com CHX) e a matriz polimérica, em todos os grupos avaliados. Concluiuse que houve a formação de nanocompósitos e que os mesmos promoveram constante liberação de CHX entre 0 a 366 horas. Esses resultados evidenciaram um forte potencial no desenvolvimento de nanocompósitos contendo fármaco antimicrobiano para aplicação odontológica.


  • IPEN-DOC 23684

    CAMPOS, LUIZA M.P. ; SANTOS, TAMIRIS M.R. ; PARRA, DUCLERC F. . Avaliação da contração de polimerização em compósitos experimentais dentários adicionados com nanopartículas de montmorilonita. In: CONGRESSO BRASILEIRO (10.) E CONGRESSO PAN AMERICANO (4.) DE ANÁLISE TÉRMICA E CALORIMETRIA, 17-20 de abril, 2016, São Paulo, SP. Anais... .

    Abstract: Esse estudo teve como objetivo desenvolver compósitos experimentais restauradores, por meio da adição de nano partículas argilominerais em uma matriz polimérica a base de BisGMA/TEGDMA, para que assim, se avalie a possibilidade de ocorrer um comportamento dimensional diferenciado no decorrer da polimerização. A caracterização dos compósitos experimentais foi realizada pelas seguintes análises: Análise Térmica- Mecânica (TMA), Difração de Raio-X (DRX) e Microscopia Eletrônica de Transmissão (MET). Foi observado que os compósitos experimentais adicionados com a nanopartícula argilomineral MMT, apresentaram os menores valores de contração de polimerização (TMA), em relação aos compósitos adicionados com a carga Vidro de Bário. Esses resultados podem estar relacionados com a interação polímero /MMT e pela formação de nanocompósitos, observados pela análise de DRX e MET.


  • IPEN-DOC 23682

    DENALDI, R.L.; BALDOCHI, S.L. ; GOMES, L. ; MAZZOCCHI, V.L. ; MORAES, J.R. ; PARENTE, C.B.R. . Yb:Er-doped LiLa(WO4)2 single crystal fiber growth. In: INTERNATIONAL CONFERENCE ON CRYSTAL GROWTH AND EPITAXY, 18th, August 7-12, 2016, Nagoya, Japan. Abstract... .


  • IPEN-DOC 23683

    SILVA, MARCUS V.; SANTO, ANA M. do E.; BALDOCHI, SONIA L. ; EIRAS, JOSE A.; LENTE, MANUEL H.. Crystal growth and characterization of lead-free based Cu-doped K0.48Na0.52NbO3 fibers by micropulling- down. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... . p. 680.

    Abstract: Lead zirconate titanate (PZT) ceramics are extensively used in piezoelectric transducer devices due its good piezoelectric properties and high Curie temperature. However, because of the toxicity of Pb element, it is necessary the development of new piezoelectric compositions with the similar electrical characteristics. In addition, it is well-known that piezoelectric single crystals present much better electrical properties than their counterpart ceramics. Among the most promising lead-free materials for piezoelectric applications sodium potassium niobate (KNN) is considered a potential candidate to replace the PZT compounds [1]. In this work undoped and Cu-doped KNN single crystal fibers with compositions near the morphotropic phase boundary (MPB) were grown by the micro-pulling-down technique (μ-PD) under three different atmospheres atmosphere: air, oxygen and argon. The μ-PD technique is a promising route because it allows obtaining crystals in a short period of time by using a reduced amount of raw materials [2]. It was verified that experimental parameters such as nozzle geometry, crucible features, temperature gradient and pulling rate were crucial for the growing of the crystals. Furthermore, it was also noticed that the atmosphere had an important impact on the crystal quality. Despite the challenges, pure and Cu-doped KNN crystals were grown and their dielectric and piezoelectric properties were investigated. Our results demonstrated that the μ-PD method is suitable for growing good KNN crystals for technological applications.


  • IPEN-DOC 23681

    SILVA JUNIOR, JOAO LUIS da; PIMENTEL, HUGO F.; ARAUJO FILHO, OSCAR O.; PILLIS, MARINA F. ; ARAUJO, EDVAL G.. Corrosion behavior of zn-al layered double hydroxide superhydrophobic films directly grown on aluminum. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... . p. 999.

    Abstract: Superhydrophobic surfaces with contact angles over 150° and contact angle hysteresis under 10° have aroused attention because of the potential applications in self-cleaning and anticorrosion coatings. The corrosion resistance comes from the permeation of ions into the metallic surface that can be minimized by the air pockets formed on the solid-liquid interface [1]. Layered double hydroxydes (LDHs) are brucite-like materials charged positively layers with anions interlayers wich are superhydrophilic micro-nanostructure that can be transformed into a superhydrophobic one after treated by a low energy surface agent like saturated fatty acid [2]. In this work, plates of 1100 aluminum and 6061 aluminum alloy (20x20x2mm3) were mechanically polished by 600# and 1200# sanding papers and ultrasonically cleaned in acetone for 10 minutes and after in isopropyl alcohol for the same time. Subsequently, the plates were immersed into a solution of 0,1M of Zn(NO3)2.6H20 in distillated water with 4 mL of ammonia and then heated at 70°C for 3h, then immersed in a 1 wt% ethanol solution of stearic acid for 90 minutes and dried at 80°C for 1h. The resulting microstructure of the films was observed by SEM. Polarization curves were produced when the plates were immersed in 3,5%wt NaCl solution at room temperature. Afterwards, both aluminum plates showed superhydrophobicity. The Zn-Al LDH films showed curved platelets and flower-like structures. The corrosion density for the uncoated 1100 and 6061 aluminum alloys were 3.7 and 8.4 μA/cm2, respectively. For the same coated samples the corrosion densities were almost one order of magnitude less: 0.33 and 0.45 μA/cm2 for 1100 and 6061 alloys, which demonstrate the better corrosion behavior of the treated samples.


  • IPEN-DOC 23680

    MARCELLO, BIANCA A. ; GERIBOLA, GUILHERME A. ; ARAUJO, EDVAL G.; PILLIS, MARINA F. . Evaluation of the photocatalytic activity of TiO2 films grown by mocvd technique. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... . p. 944.

    Abstract: The presence of pollutants such as insecticides and antibiotics in wastewaters and drinking water is nowadays one of the major environmental problems. Titanium dioxide has emerged as an excellent photocatalyst for pollutant degradation. In this research TiO2 films with thicknesses of 184, 395 and 720 nm were grown at 400ºC by metallorganic chemical vapor deposition (MOCVD) on borosilicate substrates. Titanium isopropoxide IV was used both as titanium and oxygen precursors. The films were analyzed by x-ray diffraction and the results suggested that anatase was the only phase formed. The photocatalytic behavior of the TiO2 films on the degradation of methyl orange dye solution in different values of pH was evaluated by spectrophotometry under UV irradiation. The results of the dye degradation show that the lower the pH of the solution, the higher the efficiency of the TiO2, independently of the thickness of the film. The best photocatalytic performance was observed for films with 395 nm of thickness at pH 2.00, which showed 65.3% of efficiency in the degradation of the dye. Similar result was obtained by Duminica et al.1 that grew TiO2 films by MOCVD and reported the best result for films with approximately 300 nm of thickness. According to these authors, when the film is very thick and dense, most of the pairs electron/hole is generated inside the film, and do not reach the surface, and when the film is very thin, only a small portion of the incident light is absorbed by TiO2. Thus, there is an optimal thickness to obtain the best results. The findings of the present study permit to conclude that TiO2 films produced by MOCVD are promising for application as photocatalyst material in the degradation of organic pollutants as methyl orange dye.


  • IPEN-DOC 23679

    LEIVAS, T.P.; NEVES, M.D. ; PILLIS, M.F. ; PIERETTI, E.F.. Análise de fratura de implante ortopédico metálico para substituição total de joelho. In: CONGRESSO LATINO-AMERICANO DE ORGAOS ARTIFICIAIS E BIOMATERIAIS, 9; CONGRESSO DA SOCIEDADE LATINO AMERICANA DE BIOMATERIAIS, ORGAOS ARTIFICIAIS E ENGENHARIA DE TECIDOS, 13., 24-27 de agosto, 2016, Foz do Iguaçu, PR. Resumo... . p. 83.

    Abstract: Fraturas resultantes de processos de desgaste e de fadiga foram identificadas como as principais causas de falhas em biomateriais, especialmente em implantes que atuam no local do osso ou outros tecidos duros, pois estão sujeitos a condições que envolvem cargas cíclicas severas. No caso de biomateriais, os tipos de falhas acima mencionadas também devem ser avaliados sob o efeito de degradação ou corrosão, porque eles estão em contato direto com os fluidos corporais. A presente pesquisa analisou a fratura induzida pela fadiga - corrosão de um implante ortopédico produzido com o aço inoxidável austenítico ASTM F139. A morfologia, composições das interfaces e posterior comportamento corrosivo foram caracterizados por microscopia eletrônica de varredura (MEV) acoplada à espectrometria de energia dispersiva (EDS). Concentração de tensões e inclusões foram os principais motivos de falha, porque nestas regiões trincas e pites de corrosão iniciam e se propagam autocataliticamente.


  • IPEN-DOC 23678

    LEVY, DENISE S. ; SORDI, GIAN M.A.A. ; RODRIGUES, DEMERVAL L. ; CARNEIRO, JANETE C.G. . Enhancing communication on Radiological Protection throughout Brazil. In: CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... .

    Abstract: This paper focus on the potential value of Information and Communication Technologies (ICTs) to enhance communication on Radiological Protection throughout Brazil. The servers processing power added to the technology of relational databases allow to integrate information from different sources, enabling complex queries with reduced response time. It is our objective to provide radioactive facilities a complete repository for research, consultation and information on radiological protection in an integrated and efficient way. This web-based project works informatization of Radiological Protection Programs according to the positive tree published by AIEA in its Safety Series No. 102, the most generic and complete tree for an appropriate and effective radiation protection program. Up to this moment, the website counts on concepts, definitions and theory about optimization and monitoring procedures, interrelating information, currently scattered in various publications, in order to meet both Brazilian and international recommendations. The project involves not only the collection and interrelationship of existing information in the several publications, but also new approaches from some recommendations, such as potential exposures. Only few publications develop expressively the issue and, even though they provide fundamental theory, there is still lack of knowledge of failure probabilities, which currently constitutes a broad research field in radiological protection. This research proposes the development of fault trees and the analysis of different scenarios, suggesting paths to quantify probabilistically the occurrence of potential exposures, as well as probabilities to reach a certain level of dose. It is our target to complete the system in a near future, including other relevant issues, such as safe transport of radioactive materials, emergency response, radioactive waste management and decommissioning, among others. We believe the use of information technology for the radiological protection programs shall contribute greatly to provide information to Brazilian radioactive facilities throughout the country, spreading information to as many people as possible, minimizing geographic distances and stimulating communication and development.


  • IPEN-DOC 23677

    CARNEIRO, J.C.G.G. ; ALVES, A.S.; SANCHES, M.P. ; RODRIGUES, D.L. ; LEVY, D.S. ; SORDI, G.M.A.A. . Basic characterization of a radioactive facility and evaluation of risk agents. In: CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Proceedings... .

    Abstract: This is an exploratory and descriptive study with qualitative and quantitative approaches to investigate the basic characterization of a Brazilian radioisotope production facility through ample knowledge of the workplace, workforce, task performed and identification of present risk agents in labor environment. The studied sample was composed by 102 workers distributed in eight work processes. Data were collected from April 2013 to July 2014 by applying questionnaire forms and complemented by interviews and observations. The descriptive statistical analysis included ANOVA test and non-parametric tests, among others. For the purpose of this study, there was adopted a significance level of 5% (p<0.05). The analysis of socio-demographic variables demonstrated that male gender predominated in total sample (74.5%) and the mean age of the workers was (51.8 ± 1.7) years. The largest percentage of the responders (70.6%) was technician-level workers. Regarding task-related exposure, there was considered that all groups presented the same exposure profile. At the workplace, there were identified 17 risk agents, including physical, chemical, biological, ergonomic and accident risks. The workforce was categorized into 3 risk groups according to relative frequency distribution of the occupational risks. Among the sixteen qualitative variables studied at the workplace, only three of them did not demonstrate relative frequency. The only variable that showed association with the three risk groups was the possibility of the contact with ionizing radiation. The study provided an overview of the perception of occupational risk at the facility. According to the results obtained by statistical analysis, most of the qualitative variables presented statistically significant association (p<0.001) related to the occurrence of occupational risks. Even though the workers may be potentially exposed to different risk agents, the ionizing radiation was the main physical risk factor observed in this facility.


  • IPEN-DOC 23676

    SILVA, L.G. da; ROSSI, W. de . Blackening effect in an implant steel by ultrashort laser pulses. In: WORKSHOP SOBRE SEMICONDUTORES E MICRO E NANOTECNOLOGIA, 12., 12-13 de abril, 2016, São Paulo, SP. Abstract... .

    Abstract: In this work, we studied the possibility of turning black the surface of an ASTM F138 stainless steel sample after irradiation by femtosecond laser pulses. The irradiations were performed varying the number N of laser pulse overlapped. After irradiation there was a visible change in coloration of the samples, which became darker as we increase the overlap rate. Employing this technique is a considerable way to produce high contrast markings without any changes in the metal microstructure, neither the formation of oxides coatings, which is important for a material with the level of accuracy required by this kind of implant


  • IPEN-DOC 23675

    SILVA, LEANDRO G. da ; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Alteração da cor em metais por meio de nanoestruturas periódicas formadas por laser pulsado de femtossegundo. In: CONGRESSO ANUAL DA ABM, 71., 27-29 de setembro, 2016, Riocentro, Rio de Janeiro. Anais... .

    Abstract: Neste estudo, foram estudados os efeitos da irradiação de uma amostra de aço inoxidável tipo ASTM F138 com laser de pulsos ultracurtos. As irradiações foram realizadas variando-se a velocidade de varredura do laser, ou seja, a taxa de sobreposição de pulsos. Foi observado que após a irradiação houve uma visível mudança na coloração da amostra, que se tornou mais escura à medida que aumentamos a taxa de sobreposição. Com essa técnica, pode-se realizar marcações com alto contraste sem que haja alterações microestruturais no metal, o que é importante para um material com a precisão que um implante exige.. Palavras-chave:Femtossegundo; Cor; Laser; Ripples.


  • IPEN-DOC 23674

    FERNANDES, S.M.C. ; CORREA, O.V. ; SOUZA, J.A. de ; ANTUNES, R.A.; OLIVEIRA, M.C.L. de; RAMANATHAN, L.V. . Hydrotalcite coatings to protect spent sluminum-clad nuclear fuels during long term wet storage. In: EUROPEAN CORROSION CONGRESS, September 6-10, 2015, Graz, Austria. Proceedings... Frankfurt am Main, Germany: ASMET. p. 1-8.

    Abstract: Pitting corrosion of the aluminium cladding of spent research reactor (RR) fuels in wet storage has been reported and attributed to synergistic influence of certain water parameters. Hence, use of conversion coatings to protect spent Al-clad RR fuel during long term wet storage was proposed. The objective was to develop a coating using a conventional chemical process as opposed to an electrochemical process due to constraints related to the shape of the fuel and its high radioactivity. In this context hydrotalcite (HTC) and boehmite were considered. This paper presents: (a) preparation of boehmite and hydrotalcite (HTC) coatings from different baths followed by post-coating treatments; (b) corrosion behavior of coated AA 6061 alloy; (c) results of field studies in which uncoated and coated AA 6061 alloy coupons and plates, the latter assembled as a dummy fuel element, were exposed to the IEA-R1 reactor spent fuel basin for periods of up to 14 months. The laboratory tests revealed marked increase in corrosion resistance of HTC coated specimens. In field tests the HTC coated coupons and plates did not reveal any pits. The mechanism of corrosion protection is presented.


  • IPEN-DOC 23673

    SPINELLI, EDUARDO; SAMAD, RICARDO E. ; VIEIRA JUNIOR, NILSON D. ; ROSSI, WAGNER de . Ablação seletiva por laser de femtossegundo de um filme de TiN depositado sobre um substrato de WC. In: CONGRESSO ANUAL DA ABM, 71., 27-29 de setembro, 2016, Riocentro, Rio de Janeiro. Resumo... .

    Abstract: A tecnologia de filmes finos vem sendo cada vez mais utilizada nas mais diversas áreas, principalmente em células de combustível, células fotovoltaicas além de recobrimentos com diversas funções (ópticas, decorativas, proteção ambiental, proteção ao desgaste mecânico, como barreiras de difusão, dentre outros) [1]. Os filmes são normalmente depositados por sputering, sendo muitas vezes necessário impedir o crescimento do filme, ou até mesmo, eliminar a camada em determinadas regiões da superfície, como por exemplo, para fabricação de células fotovoltaicas. Um dos métodos utilizados para remoção de filmes é a ablação seletiva por laser, que, com o avanço das técnicas de controle e equipamentos cada vez mais precisos, vem ganhando espaço nos processos industriais de fabricação [2]. No entanto, caso o limiar de ablação do filme seja maior que o do substrato, o processo poderá se tornar muito complexo, este trabalho tem por objetivo desenvolver um método que permita a remoção seletiva de filmes desta natureza, ou seja, com limiar de ablação maior que o do substrato onde foram depositados, utilizando um laser de pulsos ultracurtos.


  • IPEN-DOC 23672

    ALCANTARA, R.R.; CORREA, W.C.; ORTIZ, N. ; FUNGARO, D.A. . Using natural adsorbent bamboo biochar for rhodamine b removal from aqueous solution. In: IWA LEADING EDGE CONFERENCE ON WATER AND WASTEWATER TECHNOLOGIES, 13th, June 13-16, 2016, Jerez da la Frontera, Spain. Proceedings... .

    Abstract: Bamboo biochar was tested for its efficiency in removing Rhodamine B (RB) dye from aqueous solution. The bioadsorption process was measured through equilibrium adsorption isotherms represented by the Langmuir and Freundlich models. Nonlinear regression method was used for the determination of isotherm parameters. An error analysis was undertaken to investigate the effect of applying six error criteria to determine the best-fitting equilibrium model to the experimental data. The equilibrium data for RB adsorption well fited to the Langmuir equation, with maximum monolayer adsorption capacity of 0.638 mg g-1. The present investigations show that bamboo biochar is an alternative adsorbent for RB removal from wastewater.


  • IPEN-DOC 23671

    PETRI, A.R. ; MANGIAROTTI, A.; GONÇALVES, J.A.C. ; BUENO, C.C. . Density- normalized first Townsend ionization coefficients in a CH4-based tissue-equivalent gas mixture. In: IEEE NUCLEAR SCIENCE SYMPOSIUM, October 29 - November 5, 2016, Strasbourg, France. Abstract... Nova Iorque: IEEE.

    Abstract: Since 1950 methane-based tissue-equivalent gas (TEG) mixtures have been employed at low pressure in gaseous microdosimeters, such as tissue-equivalent proportional counters. Nevertheless, values of the first Townsend ionization coefficient (α) for these mixtures are scarce in the literature. In this work measurements of α as a function of the density-normalized electric field (E/N) were carried out in a methane-based TEG (CH4 - 64.4%, CO2 - 32.4% and N2 - 3.2%) in the range 100-300Td. The values of α were obtained using the Pulsed Townsend Technique by measuring the current growth as a function of the electric field strength in a Resistive Plate Chamber structure. Because of the parallel plate geometry, the field is uniform in our setup. As far as the authors are aware, there is only one set of experimental data on α for CH4-TEG published by Schmitz and Booz for reduced field strengths between 110V.cm-1.torr-1 (≈ 315Td) and 1780V.cm-1.torr-1 (≈ 5045Td). However, they employed a cylindrical proportional counter where α /p values were gathered from measurements of the gas gain resulting from an interval of electric field strengths. Because there are no data on α in methane-based TEG in the E/N range herein investigated, our results were compared with those expected from Magboltz simulations. Good agreement was found between experimental and simulated values of density-normalized α.


  • IPEN-DOC 23670

    VIEIRA, IMARIO; NASCIMENTO, FERNANDO C.; CALVO, WILSON A.P. . Strategic planning as a competitive advantage by using the BSC as a management tool: a case study in application of radioisotope technology at IPEN. In: WASTE MANAGEMENT SYMPOSIA, March 6-10, 2016, Phoenix, Arizona, USA. Proceedings... .

    Abstract: Strategic planning is one of the most important management tools for organizational decision making. The nuclear area represents a segment of energy production used by many countries in America, Europe and Asia. It is known that in the future nuclear energy can be a major exit to the global energy crisis. The aim of this research was to use the Balanced Scorecard (BSC) as a strategic tool for decision making in a teaching and research institution of the nuclear area - Nuclear and Energy Research Institute (IPEN), located in the city of Sao Paulo, which belongs to the National Nuclear Energy Commission (CNEN) in Brazil. The methodology used in this academic doctoral study was a case study, which considered the period of research from December 2012 to December 2015. The main results expected from this case study are: the improvement of information flow, the view, the increased visibility of an organization providing education and especially research in relation to published works, increased interaction among IPEN and the main global research institutes and centers, increasing academic production of technical articles, indicator improvement, improving the monitoring of management actions, among others. Given the expected results one can conclude that this study will be of great value to the IPEN and also for the Brazilian energy sector, as it will allow and contribute to the dissemination and demystification of nuclear power as an energy source of mankind, its peaceful applications and for the management activity of knowledge and innovation production in the nuclear area of IPEN.


  • IPEN-DOC 23656

    ARAUJO, JOAO V. de S.; COSTA, ISOLDA . Influência dos tratamentos T851 e T3 na resistência à corrosão da liga AA2198. Boletim Técnico da FATEC-SP, p. 43, 2016.

    Observação: Resumos do SICT-2016


  • IPEN-DOC 23655

    SILVA, DIEGO S. da S.; X, JONATA; ROSSI, WAGNER de ; KASSAB, LUCIANA R.P.; WETTER, NIKLAUS U. . Production and characterization of Femtosecond laser-written waveguides in a tellurium-zinc glass. In: WORKSHOP SOBRE SEMICONDUTORES E MICRO E NANOTECNOLOGIA, 12., 12-13 de abril, 2016, São Paulo, SP. Abstract... .


  • IPEN-DOC 23554

    SILVA, A.C. ; MELLO-CASTANHO, S.R.H. . Vitrificação de resíduos industriais contendo metais tóxicos: Análise da corrosão superficial após 10 anos de exposição à umidade do ar / Vitrification of industrial waste containing toxic metals: analysis of surface corrosion after 10 years of exposure to air moisture. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 2189-2200.

    Abstract: Vitrification of industrial waste containing transition metals has been widely studied as a means of mitigating harmful emissions to the environment. The chemical inertness of these materials is the key factor for their environmental safety. The chemical resistance was avaliated by hydrolytic, acid and alkali medium attack test that has been used for simulation of behavior along the time. However, there is a lack of studies that demonstrate the actual performance of such materials. Glass containing 10 to 50 Wt% of toxic metals (Cr, Ni, Cu, Zn) were prepared by the method of replacing cations modifiers for metals, having a chemical resistance and characterized evaluated by various techniques, proving the superior performance of samples containing between 30 and 40 wt% of transition metal oxides being the same or similar performance of commercial soda-lime glasses. After the initial characterization the glasses samples were exposed to the atmosphere, safe from bad weather during periods non less than 10 years at room temperature and in the shade in the region of São Paulo. In this study the samples were retested by SEM, XRD and FT-IR. Was observed the corrosion products formation in the samples with 10, 20 and 50 Wt% of metal oxide contained. The comparison with initial results to current characterizations (10 years later) showed consistent behavior with the behavior prediction obtained by the chemical resistance tests when the samples was prepared, i.e., samples containing between 30 and 40 Wt% of toxic metals was maintained the planned stability.


  • IPEN-DOC 23562

    SILVA, A.C. ; MELLO-CASTANHO, S.R. ; SANTOS, F.A. ; SANTOS, C.. Vidros biocidas baseados no sistema Nb2O5-SiO-CAO-Na2O. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIENCIA DOS MATERIAIS, 22., 06-10 de novembro, 2016, Natal, RN. Resumo... . p. 1700.

    Abstract: Neste trabalho, foram desenvolvidos vidros com base no sistema de SiO-CaO-Na2O contendo diferentes teores de Nb2O5. Estes vidros foram fundidos a 1500°C por 4 horas seguido de “quenching” em molde metálico e recozimento a 500°C por duas horas e resfriamento natural no forno. Corpos de prova de aço inoxidável 316L e ligas de titânio foram recobertas com os materiais Os ensaios de caracterização utilizaram as técnicas de DRX, FT-IR e análise da expansão térmica. Também realizou-se ensaios de citotoxicidade utilizando a metodologia de absorção de vermelho neutro onde foi indicado o crescimento celular normal, o que permite a sua utilização como biomaterial. A atividade biocida foi avaliada através da incubação de vidro em suspensão bacteriana (E.coli) a 37°C sob agitação. A composição com alto teor de de SiO2 e baixo teor de Nb2O5 apresentou maior atividade biocida e o coeficiente de expansão térmica indicam compatibilidade dos materiais térmica com o aço inoxidável 316L e ligas de titânio.


  • IPEN-DOC 23563

    MELLO-CASTANHO, SONIA ; SANTOS, FELIPE ; BARTOLOME, JOSE; SILVA, ANTONIO . Coating glass-ceramics bioactive based on Nb2O5-SiOCaO- Na2O system. In: INTERNATIONAL CONGRESS ON CERAMICS, 6th, August 21-25, 2016, Dresden, Germany. Abstract... .

    Abstract: The request for biomaterials which interact and provide proper feedback to bodily environment is increasing and so, the need for alternative materials development, from the process or biological feedback points of view, is a necessity. In this context, glass and glassceramic are interesting alternatives due to their chemical and structural characteristics possibilities. The surface coating of a specific implant with bioglass associated to biocide activity can lead to a significant impact on patient life quality, reducing risks associated to prostheses replacement due to infections, which is currently one of the most concerning and important factors in implantology. In this work, glassceramic materials based on SiO-CaO-Na2O system containing different percentages of Nb2O5 were developed. Glasses were melted at 1500°C and thermally treated at 750°C-2h. The materials were characterized by X-Ray Diffraction (XRD), to analyses indicated partial crystallization of glassy matrix. The Fourier Transform Infrared (FTIR) Spectroscopy and Dilatometry also were used to structural and thermal behavior analyses respectively. Citotoxicity tests were performed using neutral red uptake methodology and indicated normal cell growth, which enables the use as biomaterial. Biocide activity was evaluated through glass-ceramic incubation in bacterial suspension (Escherichia coli) at 37°C under shaking. A composition with higher contents of SiO2 and Nb2O5 presented higher biocide activity and coefficient of thermal expansion (CTE) evaluated indicate thermal connection with stainless steel 316L and titanium alloys.


  • IPEN-DOC 23669

    NAVILLE, WILLIAM ; COSTA, ISOLDA . Uniaxial deformation effect on the fatigue-corrosion resistance of the ISO 5832-1 stainless steel for biomaterials application. In: WORLD BIOMATERIALS CONGRESS, 10th, May 17-22, 2016, Montreal, Canada. Abstract... .

    Abstract: Plastic deformation processes modify the material fatigue-life behavior. The combination of this effect with the presence of a corrosive environment affects the material fatigue-corrosion behavior through changes in the surface material condition by slip bands creation and the interaction with surface inclusions and corrosive medium. It is expected that different directions of uniaxial deformation have different effects on the corrosion-fatigue behavior of the material once the extent of surface interactions are different in each case. In this study, the effect of uniaxial deformation direction on the fatigue-corrosion resistance of the ISO 5832-1 stainless steel, bone plate material used in orthopedic surgery, has been investigated. Specimens were submitted to, either, compression plastic deformation or tensile plastic deformation and then the corrosion-fatigue behavior was evaluated. The fatigue-corrosion tests were carried out under a flux of the corrosive environments, either deionized water or 0.9 wt% NaCl solution. Specimens as received (without uniaxial deformation) were also submitted to fatigue-corrosion test for comparison reasons. The results did not show a significant effect of the corrosion environment on the fatigue test since similar results were obtained in both environments used. The compression plastic deformation decreased the fatigue life in comparison to the tensile plastic deformation, but both, compression, and tensile plastic deformation increased the fatigue life comparatively to the as-received material suggesting a beneficial effect of the deformation on the fatigue properties of the studied material.


  • IPEN-DOC 23668

    ARAUJO, J.V. de S.; QUEIROZ, F.M. ; TERADA, M.; ASTARITA, A.; COSTA, I. . EIS study of the microstructure influence on the corrosion behaviour of AA 2198-T3 compared to AA 2198-T851 alloy. In: INTERNATIONAL CONFERENCE ON SURFACE MODIFICATION TECHNOLOGIES, 30th, June 29 - July 1, 2016, Milan, Italy. Abstract... .

    Abstract: This paper deals with the study of the influence of the temper state on the electrochemical behavior of an high strength aluminum-lithium alloy. In particular the corrosion resistance of the AA2198 alloy in both T3 and T851 temper condition, has been evaluated by immersion tests as a function of immersion time in NaCl 0.01 mol.L-1. The evolution of the electrochemical behavior was monitored by electrochemical impedance spectroscopy (EIS) and surface observation by optical microscopy and Field Emission Gun- Scanning Electron Microscopy. The results indicated a higher electrochemical activity associated to the T851 treatment comparatively to the T3 one and this was ascribed to the more heterogeneous microstructure related to the first treatment. Severe localized corrosion was seen on the AA2198-T851 alloy after only few hours of exposure to the test medium. This type of corrosion was of the crystallographic type and was related to T1 (Al2LiCu) which is more electrochemically active than the matrix leading to localized attack. Pitting attack was seen on the AA2198-T3 alloy along the surface and it was located at the matrix-precipitates interface. The EIS results supported a faster kinetics and lower impedances associated to the AA2198-T851 comparatively to the AA2198-T3 alloy according to the surface observation along the test period.


  • IPEN-DOC 23667

    TERADA, M.; QUEIROZ, F.M. ; AYUSSO, V.H.; ASTARITA, A.; COSTA, I. . Microstructural investigation of the anodized (TSA) Al-Li alloys sealed in a cerium solution. In: INTERNATIONAL CONFERENCE ON SURFACE MODIFICATION TECHNOLOGIES, 30th, June 29 - July 1, 2016, Milan, Italy. Abstract... .

    Abstract: The AA2198 is a third generation of Al-Li alloy developed for use in the aircraft industry. It is highly susceptible to localized corrosion and it is usually protected by anodizing. Sealing treatments of the anodic layer provide further protection. In this study, samples of the AA2198 alloy were anodized in tartaric sulfuric acid (TSA) solution and subsequently sealed, either in boiling water or in a solution with cerium ions. The surface of the treated samples was investigated by Field Emission Gun-Scanning Electron Microscopy and X-ray energy dispersive analysis. Defects were found in the anodic layer due to the complex microstructure of the AA2198 alloy. The corrosion resistance of the anodized and sealed samples was studied by electrochemical impedance spectroscopy in 0.5 mol.L-1 NaCl solution and compared to that of anodized and unsealed samples. EIS results showed that the sealing treatment in cerium solutions resulted in increase in impedance with time of immersion. Surface observation and EDX analysis showed increase in cerium content with time of test at the defects in the anodic layer sealed in cerium containing solutions and the increasing blockage of the defects in this layer. The EIS results also showed that the impedance associated to this type of samples increased with time whereas it decreased for sealed samples in boiling water. The surface observation and EIS responses indicated a healing process associated to sealing in the cerium solution.


  • IPEN-DOC 23666

    LEITE, ANTONIO M. dos S. ; TERADA, MAYSA ; PEREIRA, VICTOR F.; COSTA, ISOLDA . Resistência à corrosão do aço lean duplex UNS S82441 submetido à soldagem por atrito com pino não-consumível. In: CONGRESSO BRASILEIRO DE CORROSAO, 36.; INTERNATIONAL CORROSION MEETING, 6th; CONCURSO DE FOTOGRAFIA DE CORROSAO E DEGRADAÇAO DE MATERIAIS, 20.; EXPOSIÇAO DE TECNOLOGIAS PARA PREVENÇAO E CONTROLE DA CORROSAO, 36., 16-20 de maio, 2016, Búzios, RJ. Anais... Rio de Janeiro, RJ: ABRACO. p. 1-10.

    Abstract: Duplex stainless steels have been widely used in the manufacture of equipment and piping for oil & gas industry, in onshore and offshore service. However, whenever they are exposed to high temperatures the precipitation of deleterious phases might occur. The precipitates drastically reduce the corrosion resistance and mechanical properties of these materials. The friction stir welding (FSW) process has been considered as an alternative to replace the conventional welding processes in duplex stainless steels. FSW is a solid state welding process avoiding many of the problems associated to conventional fusion techniques. In this paper, specimens of the various zones affected and nearby the FSW, specifically the nugget or stir zone (SZ), the heat affected zone (HAZ) and the base metal (BM) of welded lean duplex UNS S82441 had their corrosion resistance evaluated by eletrochemical tests. The results indicated that the HAZ and SZ regions presented similar localized corrosion resistance to that of the BM showing that it is a potential technique for replacing the conventional processes with advantageous corrosion resistance properties.


  • IPEN-DOC 23665


    Abstract: AA2524 is a relatively new brand of aluminum alloy designed to build lightweight structural components in aerospace industry. To be employed in aircrafts, high strength Al alloys need to be protected from corrosion by a robust protection system. One of the steps applied in the protection protocol is anodizing, which is known to greatly improve the corrosion resistance of Al alloys. In the present investigation, a sol-gel hybrid layer was applied as a post-treatment step for anodized AA2524 and the corrosion resistance of the system evaluated by means of EIS measurements and salt-spray tests. The anodizing process was performed in a tartaric-sulfuric acid (TSA) bath, which is more environmentally friendly than the traditional chromic acid anodizing baths, and the sol–gel solution was prepared by mixing tetraethoxysilane (TEOS) and 3-glycidyloxypropyl-trimethoxysilane (GPTMS) precursors in a solution with high water content. For comparison reasons, TSA anodized samples were also hydrothermally sealed in boiling deionized water. The results of both EIS and salt-spray tests demonstrated superior corrosion resistance for the anodized samples post-treated with the hybrid sol-gel layer. Electrical equivalent circuit fitting of the EIS data indicated that the hybrid sol-gel layer strongly hinders electrolyte penetration through the porous layer, better protecting the underlying substrate.


  • IPEN-DOC 23664

    ALMEIDA, THALLIS L.; QUEIROZ, FERNANDA M. ; TERADA, MAYSA ; COSTA, ISOLDA ; CAPELOSSI, VERA R.. Efeito da selagem hidrotérmica com adição de íons Ce (III) na proteção à corrosão da liga de alumínio AA7475-T761 anodizada em banho ácido tartárico-sulfúrico. In: CONGRESSO BRASILEIRO DE CORROSAO, 36.; INTERNATIONAL CORROSION MEETING, 6th; CONCURSO DE FOTOGRAFIA DE CORROSAO E DEGRADAÇAO DE MATERIAIS, 20.; EXPOSIÇAO DE TECNOLOGIAS PARA PREVENÇAO E CONTROLE DA CORROSAO, 36., 16-20 de maio, 2016, Búzios, RJ. Anais... Rio de Janeiro, RJ: ABRACO. p. 1-13.

    Abstract: The aluminum alloys of series 7XXX have excellent mechanical properties combined with low density and are often used in the aeronautic industry. However, their susceptibility to localized corrosion requires the use of protective coatings to ensure their long-term life. In the aircraft industry, the anodization process is an effective corrosion control method. Besides, the anodized layer sealing treatment of parts that are not used with coatings, provide further protection. However, both processes, anodization and sealing, generally employ baths containing Cr (VI) ions. These are highly toxic to the environment and carcinogenic. In this work, the AA7475-T761 alloy was anodized in a solution of tartaric-sulfuric acid (TSA) and then the anodic layer was hydrothermally sealed in aqueous solutions, either with or without the addition of Ce (III) ions. The effect of sealing time on the corrosion protection of the anodic layer was investigated for periods of sealing corresponding to 2.5 min, 5 min, 7.5 min and 10 min. The corrosion resistance of the anodized alloy samples was evaluated by electrochemical impedance spectroscopy (EIS) as a function of exposure time to a sodium chloride electrolyte. Higher impedances were associated with anodic layers hydrothermally sealed for 7.5 min and 10 min in Ce (III) ions containing solution. Surface observation was carried out by scanning electron microscopy (SEM) and the results indicated that hydrothermal treatments in solution with Ce (III) ions leads to anodic layers with decreased porosity.


  • IPEN-DOC 23663

    SANTOS, WAGNER I.A. dos ; COSTA, ISOLDA ; TOMACHUK, CELIA R.. Hydrothermal surface treatments with Cerium and Glycol molecules on the AA 2024-T3 clad alloy. In: INTERNATIONAL ALUMINIUM CONFERENCE, 13th, September 21-23, 2016, Naples, Italy. Proceedings... .

    Abstract: New treatments for replacement of chromate require lower toxicity and corrosion protection. This study aims to investigate the influence of the combination of a Ce conversion coating (CCCe) with glycol molecules on the corrosion resistance of the AA2024-T3 clad (AA1230). The corrosion resistance of surface treated and untreated samples was evaluated by electrochemical techniques (electrochemical impedance spectroscopy, polarization tests and open circuit potential). These tests were complemented by salt spray tests to accelerate the corrosive effects of weathering. The surfaces were analyzed after corrosion tests by scanning electron microscopy with X-ray energy dispersive detector (SEM - EDX). The results of the CCCe samples in combination with glycol were compared with that of the surface with chromate layer and the results showed that the CCCe treatment is a candidate for replacement of chromating with the advantage that it does not generate toxic residues. The self-healing capacity of the new treatment tested was indicated by the increased formation of corrosion products deposition on top of Fe rich intermetallis in the AA1230 clad with time of exposure to the electrolyte.


  • IPEN-DOC 23662

    ALMEIDA, THALLIS L.; QUEIROZ, FERNANDA M. ; TERADA, MAYSA; COSTA, ISOLDA ; CAPELOSSI, VERA R.. On the effects of hydrothermal treatments on the corrosion resistance of the TSA anodized AA7475-T761 alloy. In: INTERNATIONAL ALUMINIUM CONFERENCE, 13th, September 21-23, 2016, Naples, Italy. Proceedings... .

    Abstract: The effect of hydrothermal treatment time on the sealing and corrosion resistance of the anodized AA7475-T761 aluminium alloy has been investigated in this study. The treatments tested are environmental compatible and has not chromium ions involved. Anodizing was carried out by tartaric-sulphuric anodizing (TSA) and this was followed by hydrothermal treatments for partial sealing, either with or without propyleneglycol (PRG) and/or cerium ions. Four different treatment times were tested, specifically, 2.5, 5.0, 7.5 and 10 min. The corrosion resistance of the treated samples was evaluated by Electrochemical Impedance Spectroscopy (EIS) and the anodic layers formed by anodizing and hydrothermal treatments were characterized by Scanning Electron Microscopy (SEM). The EIS results indicated that the best corrosion resistance was related to the treatments that combined hydrothermal treatments in boiling water with PRG for 10 minutes or boiling water with PRG and cerium ions for 5 min. The SEM images for the samples showed the formation of a homogeneous anodic layer and the thickness is approximately 3 m. It was noticed that the porosities were not completed sealed by the treatments tested and this was on purpose in order to allow coating adhesion to the anodic layer.


  • IPEN-DOC 23661

    COSTENARO, HELLEN; QUEIROZ, FERNANDA M.; TERADA, MAYSA; OLIVIER, MARIE-GEORGES; COSTA, ISOLDA ; MELO, HERCILIO G. de . Corrosion protection of AA2524-T3 anodized in tartaric-sulfuric acid bath and protected with hybrid sol–gel coating. In: INTERNATIONAL ALUMINIUM CONFERENCE, 13th, September 21-23, 2016, Naples, Italy. Proceedings... .

    Abstract: 2xxx Al alloys are particularly sensitive to localized corrosion in chloride environments and in order to maintain their integrity, minimize maintenance needs and repairs, and to maximize component life, protective treatments are required. Anodizing is an electrochemical process based on the growth of the Al oxide layer by applying anodic potentials. One of the alternatives is tartaric/sulphuric acid (TSA) anodizing, which is environmentally compliant and provides corrosion resistance properties, compatible with the requirements of the aerospace industry with appropriate paint adhesion. In this study, AA2524-T3 specimens were anodized in a tartaric-sulfuric acid bath (TSA) and subsequently protected by application of a hybrid sol–gel coating. The sol–gel coating was prepared using a solution with high water content (58 %v/v) and obtained by the hydrolysis and condensation of tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). The corrosion resistance evaluation of both unsealed and coated samples was carried out in a sodium chloride solution by EIS as a function of immersion time. The results were also fitted using electrical equivalent circuits.


  • IPEN-DOC 23660

    BUGARIN, ALINE F.S. ; QUEIROZ, FERNANDA M.; TERADA, MAYSA; MELO, HERCILIO G. de; COSTA, ISOLDA . Localized corrosion resistance of dissimilar aluminum alloys joined by Friction Stir Welding (FSW). In: INTERNATIONAL ALUMINIUM CONFERENCE, 13th, September 21-23, 2016, Naples, Italy. Proceedings... .

    Abstract: 2XXX and 7XXX high strength aluminum alloys are the most used materials for structural parts of aircrafts due to their high strength/weight ratio. Their joining procedure is an engineering challenge since they present low weldability. Friction Stir Welding (FSW) is a joining technology developed in the early 90´s. It is a solid-state welding process, without the use of fillers or gas shield, that eliminates conventional welding defects and has been considered of great interest for application in the aircraft industry. FSW of aluminum alloys results in four regions of different microstructures, specifically: the base material (BM), the heat affected zone (HAZ), the thermo-mechanically affected zone (TMAZ), and the nugget zone (NZ). The complex microstructure of the weld region leads to higher susceptibility to localized corrosion as compared to the BM even when similar alloys are joined. The welding of dissimilar alloys in its turn results in even more complex microstructures as materials with intrinsically different composition, microstructures and electrochemical properties are put in close contact. Despite the great interest in FSW, up to now, only few corrosion studies have been carried out for characterization of the corrosion resistance of dissimilar Al alloys welded by FSW. The aim of this study is to investigate the corrosion behavior of aluminum alloy 2024-T3 (AA2024-T3) welded to aluminum alloy 7475-T761 (AA7475-T761) by FSW. The evaluation was performed in 0.01 mol.L-1 solution by means of open circuit potential measurements, polarization techniques and surface observation after corrosion tests.


  • IPEN-DOC 23659

    ABREU, C.P. de; COSTA, I. ; MELO, H.G. de; PEBERE, N.; VIVIER, V.. Localized electrochemical impedance for characterizing welded areas of dissimilar Al alloys 2024-T3 and 7475-T761 joined by FSW. In: EUROPEAN CORROSION CONGRESS, 11th, September 21, Montpellier, France. Proceedings... . p. 1.

    Abstract: Friction Stir Welding (FSW) is an efficient way to join high strength aluminum alloys avoiding de-fects that are usually found when conventional techniques are adopted. The aeronautic industry has shown great interest in this welding method, either for joining similar or dissimilar alloys. However, FSW generates different microstructural areas that could give rise to galvanic couplings on the weld-ing area. In the present study, FSW was used to join two similar and dissimilar aluminum alloys, the AA2024 and the AA7475 alloys. To evaluate the effect of the welding process on the corrosion re-sistance of the joined alloys, electrochemical impedance spectroscopy studies, either global or local-ized (LEIS), have been carried out in a low corrosive medium (0.1 M Na2SO4) or with a small addi-tion of chlorides (0.1 M Na2SO4 + 0.001 M NaCl). A gel visualization technique was also employed to detect possible galvanic couplings of the different zones formed during the FSW welding. OCP measurements were also performed on both individual aluminum alloys and on the zones affected by FSW. LEIS investigations were performed at different locations above the different microstructural zones induced by the FSW process on both alloys. Galvanic coupling was clearly evidenced at the interface between the two alloys, contrary to the results reported in literature for the welding of simi-lar alloys, for which no galvanic coupling was evidenced.


  • IPEN-DOC 23658

    QUEIROZ, F.M.; TERADA, M.; COSTENARO, H.; AYUSSO, V.H.; OLIVIER, M.G.; COSTA, I. ; MELO, H.G. de. Effect of hydrothermal treatments with Ce (III) ions on the corrosion resistance of AA2524-T3 alloy anodized in TSA and protected with hybrid sol–gel coating. In: INTERNATIONAL SYMPOSIUM ON ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY, 10th, June 19-24, 2016, A Toxa, Galicia, Spain. Abstract... . p. 1.

    Abstract: Aircraft parts made of aluminum alloys are protected by organic coatings in order to avoid their exposure to the corrosive environment. Prior to organic coating, aluminum alloys are anodized usually by a process that generates toxic residues leading to environmental and health related problems [1,2]. Recently, chromium free anodizing processes have been proposed as viable alternatives to commercial chromic acid anodizing processes. The AA2524-T3 alloy was originally developed as a replacement for AA2024-T3. It presents high damage-tolerance and excellent fatigue properties. However, it also presents high susceptibility to localized corrosion, such as pitting corrosion and stress corrosion cracking. In this study, AA2524-T3 specimens were anodized in a tartaric-sulfuric acid (TSA) bath, and then exposed to hydrothermal treatment in aqueous solutions containing cerium ions at the boiling temperature. Samples with hydrothermal treatment in boiling water were also prepared for comparison reasons. Subsequently to hydrothermal treatments, the samples were coated by a hybrid sol–gel coating. The sol–gel coating was prepared using a solution with high water content (58 %v/v) and was obtained by hydrolysis and condensation of TEOS and GPTMS. The corrosion resistance of both systems was evaluated in a NaCl solution by EIS as a function of immersion time. The EIS results showed that the addition of Ce(III) ions improved the corrosion resistance of the TSA anodized AA2524-T3 alloy with sol-gel coating. The EIS results were fitted and interpreted using electrical equivalent circuits.


  • IPEN-DOC 23657

    COSTA, I. ; ROGERO, S. ; TERADA, M.; MARQUES, R.A. . Corrosion resistance and cytotoxicity evaluation of ferromagnetic materials for use in dental prosthesis. In: CONGRESSO LATINO AMERICANO DE ORGAOS ARTIFICIAIS E BIOMATERIAIS, 9., 24-27 de agosto, 2016, Foz do Iguaçu, PR. Abstract... .

    Abstract: In this study, the corrosion resistance and cytotoxicity of the AISI 444 ferritic stainless steel (SS) was investigated for dental magnetic attachments application and compared with that of a comercial universal keeper for dental attachment (Neo-magnet System). In vitro cytotoxicity analysis was performed by the red neutral incorporation method to evaluate one of the criteria of biocompatibility. The results showed that the AISI 444 SS tested presents no cytotoxicity. The corrosion resistance of this SS was investigated by anodic polarization methods and electrochemical impedance spectroscopy (EIS), in a saline phosphate buffer solution (PBS) at 37 oC. The electronic properties of the passive film at the AISI 444 surface were evaluated by Mott-Schottky approach. All tested materials showed passivity in the PBS médium. The NeoM steel showed higher susceptibility to pitting than the AISI 444 SS and this was realted to its composition and microsctructure. The oxide film on the NeoM steel was associated to a higher doping concentration than the passive film on the AISI 444 SS.


  • IPEN-DOC 23989

    SILVA, F.S. ; RODRIGUES, V.G. ; MISSO, A.M. ; MORAIS, V.R.; YAMAGATA, C. . Síntese de silicato de lantânio tipo apatita pelo método sol-gel utilizando silicato de sódio como fonte de sílica / Synthesis of lanthanum silicate apatite-type by sol-gel method using sodium silicate as source of silica. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 156-167.

    Abstract: Ceramics of lanthanum silicate apatite-type have been studied with great technological interest at IT-SOFC applications (Intermediate Temperature Solid Oxide Fuel Cell) for having good ionic conductivity at intermediate temperatures (600-800°C), higher than that of YSZ (Ytria Stabilized Zirconia) in high-temperature SOFCs. At this work has made the synthesis of the lanthanum silicate apatite-type from Na2SiO3 as a source of silica by the modified sol-gel method that allowed the formation of ceramic powders of lanthanum silicate apatite-type in calcination temperature at 900°C, which is much lower than those other methods of synthesis. Analysis by x-ray diffraction (XRD) showed the lanthanum silicate apatite-type phase as the main phase. Scanning electron microscopy was used to nanometric powders observation.


  • IPEN-DOC 23981

    XAVIER, G.L.; SILVA, F.R.O. ; GUGLIOTTI, C.F.; USSUI, V. ; LIMA, N.B. . Deposição eletroforética de hidroxiapatita em titânio metálico / Electrophoretic deposition of hydroxyatapite on metalic titanuium. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 1827-1838.

    Abstract: Titanium is commonly used in the manufacture of orthopedic and dental implants due to its high corrosion resistance and good mechanical properties. However because of its grey color, the implant becomes visible due to transparency of peri-implant tissues in patients with thin gingival biotype. In this work, hydroxyapatite obtained by chemical precipitation method (Hap-S) was coated on titanium substrate by electrophoretic deposition technique, to improve implant integration in the organism and change their color. Hap-S powders were characterized by XRD, FTIR and SEM. The EPD was performed in dental grade titanium substrate with 10x10mm in dimension, at 80V, 60V and 40V for 40s, 60s and 120s. After, the coatings were dried at room temperature and sintered at 800°C for 1h. The samples were characterized by XRD and SEM. Results showed that deposition is more effective for shorter times and intermediate voltage, yielding homogeneous and crack free deposits.


  • IPEN-DOC 23978

    ARAUJO, ONARA M.M.; LOMBELLO, CHRISTIANE B.; USSUI, VALTER ; LIMA, NELSON ; ROSSI, WAGNER ; RIBEIRO, CHRISTIANE. Estudo comparativo de diferentes superfícies do compósito alumina-zircônia de natureza bioinerte / Comparative study of different surfaces of the bioinert composite of the alumina-zirconia. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 1794-1805.

    Abstract: Different techniques for the improvement of surface conditions have been proposed in the development of biomaterials. This paper proposed a study comparing three different patterns of ceramic surfaces for 85% Al2O3-15% ZrO2. The surface properties of the samples were analyzed after sintering, and were compared the surface without treatment, with polished surfaces, and textured surfaces femtosecond laser. The samples were characterized by DRX and density and the surfaces were characterized for roughness, wettability and scanning electron microscopy. It was also analyzed the cell adhesion behavior, using Vero cell (ATCC CCL-81). The results showed a strong correlation between the roughness and wettability with adherence behavior and cell morphology. It was observed that the effect of the laser made the surface exhibit a behavior hydrophobic with a tendency micro-roughness controlled and generated. Despite the lower participation rate, compared to other surfaces, there was more intense cell spreading on these surfaces, and vesicles on the surface of the adhered cells, showing a favorable metabolic activity of cells in this type of surface.


  • IPEN-DOC 23965

    RIBEIRO, S.; GENOVA, L.A. ; RIBEIRO, G.C.; OLIVEIRA, M.R.; BRESSIANI, A.H.A. . Efeito da temperatura e da taxa de aquecimento na sinterização do SiC aditivado com Al2O3-Dy2O3 e Al2O3-Yb2O3 / Effect of temperature and heating rate on the sintering of SiC doped with Al2O3-Dy2O3 and Al2O3-Yb2O3. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 1178-1189.

    Abstract: Compacts of SiC+10 vol.% (Al2O3+Dy2O3) and SiC+10 vol.% (Al2O3+Yb2O3) mixtures were prepared by cold isostatic pressing and sintered for 60 min in a dilatometer at 1800 and 1900°C, applying heating rates of 10, 20 and 30°C/min. An evaluation of the complete sintering cycle indicated that the heating rates did not significantly affect the shrinkage, but that the sintering temperature may be a relevant factor. The compacts sintered at 1900°C showed 9% higher shrinkage, on average, than those sintered at 1800°C. The maximum shrinkage rates of both mixtures occurred at temperatures below the sintering thresholds, temperatures and heating rates. It was also noted that after the formation of the liquid, the mechanisms of particle rearrangement and solution-precipitation were not as fast as those reported in the literature, but were responsible for much of the shrinkage during the sintering cycle.


  • IPEN-DOC 23964

    MELLO, R.M. ; BRESSIANI, A.H.A. . Análise de trincas causadas por choque térmico em carbeto de silício / Analysis of cracks caused by thermal shock in carbide silicon. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 1165-1176.

    Abstract: The aim of this study is to analyze the formation and propagation of cracks, as well as the occurrence of thermal fatigue in SiC subjected to thermal shock. Samples were prepared with 90%SiC+10%(Y2O3:Al2O3) mole, in the proportions 1:3 and 1:4 of additives. The compacted samples were sintered at 1750 °C, 1850 °C and 1950 °C in graphite resistive furnace. The thermal cycles were performed by heating at two different temperatures (600 °C and 900 °C) in a tubular furnace, and quenched in water. Analysis of cracks was performed by scanning electron microscopy on samples from flexural strength test after 1 and 50 thermal cycles, or after thermal fatigue. The sintering temperature and thermal cycle have a great influence on the formation and propagation of cracks. The samples sintered at 1950 °C, despite having a significant number of cracks, are the only ones not introduce thermal fatigue to 900ºC.


  • IPEN-DOC 23963

    MELLO, R.M. ; BRESSIANI, A.H.A. . Influência da microestrutura na resistência ao choque térmico do SIC / Influence of microstructure on resistance to thermal shock of SIC. In: CONGRESSO BRASILEIRO DE CERAMICA, 60., 15-18 de maio, 2016, Águas de Lindóia, SP. Anais... . p. 1153-1164.

    Abstract: The aim of this study is to analyze the influence of microstructure on thermal shock resistance of liquid phase sintered SiC, as this is a very required property in various technological applications. The microstructure can influence the thermal shock resistance because large grains tend to generate toughening mechanisms, reducing damage to the material. For this analysis, samples with 90 % SiC 10 % + (Y2O3:Al2O3) in the proportions 1: 3 and 1: 4 mole, were compacted and sintered at 1750 ° C , 1850 ° C and 1950 ° C. The thermal shock was performed by heating the sample in a tubular furnace and quenched in water. Damages caused by thermal shock were evaluated by monitoring the elastic modulus of samples. Micrographs were done by electron microscope and grain size distribution at Quantikov software. The samples sintered at 1950 °C have greater grain size and, consequently, greater thermal shock resistance.


Próxima página

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

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

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

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

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


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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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



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

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

Repositórios Digitais Institucionais: a experiência

do Instituto de Pesquisas Energéticas e Nucleares


Mery P. Zamudio Igami

Biblioteca Terezine Arantes Ferraz

1 Repositórios Digitais Institucionais – RDI

A tecnologia da informação modificou significativamente todas as atividades rotineiras da sociedade. O surgimento das redes de comunicação transformou o ambiente onde elas atuam mudando o conceito de espaço e tempo no âmbito da comunicação e informação pela instantaneidade da transmissão de dados.

Na área de comunicação científica não foi diferente. Toda a cadeia de produção, disseminação, publicação e armazenamento de documentos científicos experimentou uma grande transformação, impactando de forma positiva a produção e consumo da informação científica na área acadêmica. O surgimento da internet e da WWW, na década de 80, aceleraram as mudanças na forma de comunicar e disseminar os trabalhos acadêmicos que passaram do suporte exclusivamente em papel para o suporte digital.

Na mesma época houve uma significativa crise mundial devido aos altos preços praticados pelas editoras no processo de assinatura das publicações periódicas, tornando inviável a sustentação das coleções pelas bibliotecas e afetando diretamente a consulta pelos usuários. Como reação da própria comunidade científica surgiu então o movimento de livre acesso à informação científica, mais conhecido por Open Access Iniciative (KURAMOTO, 2012).

Esse movimento defende a disponibilização na internet da literatura acadêmica e científica permitindo que seja lida, descarregada, distribuída, impressa e pesquisada livremente.

É importante o registro histórico desse movimento não somente porque está diretamente relacionado à criação dos RDIs, mas também porque ele possibilitou várias mudanças estruturais no fluxo da comunicação científica. Os editores perderam a exclusividade de distribuição (comercialização) da pesquisa científica, uma vez que na era digital é possível que isso seja realizado de forma descentralizada e por iniciativa de cada autor.

1.1 O movimento do Open Access Iniciative - OAI

A partir de 1999, os movimentos em favor do acesso livre à literatura científica, principalmente à literatura produzida sob financiamento público, consolidaram-se.

A comunidade acadêmica envolvida nesses movimentos corroborou o seu apoio por meio de declarações formais, dentro das quais se destaca a Declaração de Budapest – BOAI –1 em 2002, onde foram emitidos os conceitos básicos do OAI, e a Declaração de Berlim2 em 2003, onde se destacou a natureza institucional dos repositórios digitais de livre acesso como um espaço organizado baseado em regras de utilização que conferem credibilidade aos materiais publicados e em políticas de arquivamento a longo prazo.

O movimento Open Archives Iniciative desenvolveu padrões de interoperabilidade buscando facilitar a comunicação eficiente de conteúdo. Foram também estabelecidas duas modalidades para viabilizar a disponibilidade dos conteúdos: a via verde que diz respeito ao autodepósito nos RDs e a via dourada que inclui as revistas que publicam os artigos com livre acesso.

O primeiro repositório digital (ArXiv.org )3 foi instalado no laboratório de física, em Los Álamos, EU, coordenado pelo físico Paul Ginsparg (1996), motivado pela insatisfação com os rumos na política de aquisição das publicações científicas e a crescente inviabilidade das bibliotecas americanas de manter as coleções atualizadas. Daquela época para a atual aconteceram inúmeras mudanças positivas nos modelos de funcionamento dos repositórios promovidas pela evolução da TI.


1 Budapest Open Access Iniciative - http://www.budapestopenaccessinitiative.org

2 Open Access - http://openaccess.mpg.de/Berlin-Declaration

3 General Information about Arxiv - http://arxiv.org

Não existe um modelo único para a criação dos RDIs; cada instituição define a política de depósito adequada ao contexto da sua comunidade. O importante é que essa comunidade valide e utilize a plataforma tornando-a uma vitrine da sua produção científica.

No país, o movimento de Acesso Aberto e construção de Repositórios Digitais Institucionais tiveram um grande incentivo e apoio técnico do Instituto Brasileiro de Informação em Ciência e Tecnologia – (IBICT) (INSTITUTO BRASILEIRO DE CIÊNCIA E TECNOLOGIA, 2009). De acordo com o Diretório internacional de RDIs – o DOAR4, até o momento, há no país 153 repositórios digitais em funcionamento, dos quais a maioria é mantida pelas instituições onde a comunidade produz os trabalhos científicos. Desses RDIs, 74% utilizam o software Dspace5.

1.2 O Projeto de Lei sobre os Repositórios Digitais

Em 2007, foi apresentado o Projeto de Lei no senado PL1120/2007 (BRASIL, 2007), que torna obrigatório nas universidades e institutos de pesquisa o desenvolvimento e implantação de RDIs nas instituições de origem, bem como torna obrigatório o autodepósito da produção científica por parte dos seus pesquisadores. Além disso, o Projeto de Lei determina a formação de uma comissão de alto nível para discutir, propor e estabelecer uma política de livre acesso à informação científica. Além de simplesmente criar mecanismos de disseminação da informação científica, o Projeto propõe a criação de uma comissão para discutir políticas e estabelecer diretrizes a serem adotadas em nível nacional pelas instituições que produzem informação científica.

1.3 O que são os RDIs?

Os RDIs constituem atualmente um avanço na gestão do conhecimento intelectual. Podem receber diversas denominações tais como equipamentos institucionais, observatórios digitais, instrumentos ou ferramentas de gestão de conhecimento e outras.


4 The Directory of Open Access Repositories – OpenDOAR - http://www.opendoar.org

5 Software livre para construção de Repositorios Institucionais Digitais (Dspace) - http://www.ibict.br/pesquisa-desenvolvimento-tecnologico-e-inovacao/Sistema-para-Construcao-de-Repositorios-Institucionais-Digitais

Um dos aspectos mais importantes dos RDIs é que eles estão inseridos na política institucional de gestão do conhecimento e são essencialmente instrumentos gerenciais de onde se obtém indicadores para auxiliar na gestão da política científica das instituições de pesquisa.

Sob a ótica documentária um RDI constitui um serviço de informação científica em ambiente digital, interoperável e de acesso aberto, dedicado ao gerenciamento da produção científica de uma instituição. Contempla a reunião, armazenamento, organização, preservação, recuperação e, sobretudo, a ampla disseminação e visibilidade da informação científica produzida na instituição.

1.3.1 O que caracteriza um repositório digital?

a) a organização, armazenamento, acesso e distribuição de documentos digitais;

b) a utilização de padrões abertos acessibilidade;

c) as funcionalidades que o software selecionado permite;

d) a utilização de metadados com padrão internacional – interoperabilidade;

e) o arquivo digital anexado;

f) o acesso de buscadores para elaboração de rankings internacionais - visibilidade;

g) o autodepósito dos trabalhos;

h) a monitoração, controle e elaboração de indicadores.


O prestígio de uma instituição de pesquisa está fortemente vinculado aos resultados dos elementos intangíveis, por exemplo, qualidade no ensino da pós-graduação, e tangíveis como os resultados da pesquisa, entre eles a Produção científica. Tradicionalmente, o IPEN, por meio da sua unidade de informação, mantém a sua produção científica organizada e atualizada desde sua criação em 1956. No entanto, devido ao avanço da tecnologia da informação, tornou-se necessário atualizar a plataforma gerenciadora dessa informação já armazenada, com a consequente modernização no processo de gestão do capital intelectual.

No decorrer de 2013, seguindo outras instituições no país, como por exemplo, a Universidade de São Paulo, a Universidade Estadual Paulista e a Universidade Estadual de Campinas, a Direção do IPEN decidiu criar o seu repositório, uma vez que a matéria prima para concretizar esta ação já se encontrava disponível e organizada de tal forma que se garantiria a sustentabilidade do RDI.

A política de gestão da produção científica é uma prática rotineira no IPEN. Diferentemente da maioria dos repositórios em funcionamento, o RDI do IPEN já nasce com um volume significativo de matéria-prima digital organizada, com políticas definidas de auto arquivamento e de preservação da produção científica.

Porém, o fator determinante de sucesso foi o modelo de indexação e organização dos documentos adotado pela biblioteca desde o início em 1976, quando ainda se constituía em uma base de dados referencial. Este fato facilitou o processo de migração e compatibilização dos metadados para o novo padrão internacional adotado, o Dublin Core, garantindo interoperabilidade com outros repositórios digitais, uma das principais características dos RDIs.

Em novembro de 2013, foram iniciados os trabalhos de construção do RDI do IPEN. Inicialmente foram programadas visitas do grupo de informática e da biblioteca a instituições com experiências bem-sucedidas, como, por exemplo, o Instituto de Pesquisas Espaciais – (INPE) em São José dos Campos e a Universidade de São Paulo- USP, com o objetivo de conhecer melhor o projeto de RDIs dessas instituições e selecionar o modelo mais adequado à realidade do IPEN.

As visitas técnicas embasaram a decisão de selecionar o software Dspace para confecção do repositório do IPEN. O Dspace é um software livre especializado no gerenciamento de repositórios resultante de um projeto colaborativo da MIT Libraries e da Hewlett-Packard Company, amplamente utilizado no mundo. No Brasil, graças ao incentivo do IBICT em Brasília, o DSpace é utilizado por 75% das instituições que possuem repositórios.

2.1 O processo de migração

Em dezembro de 2013, foi iniciado o processo de criação do novo repositório do IPEN, após um estudo preliminar do software e contratação de uma empresa para a capacitação das equipes da biblioteca e da informática.

Nos meses seguintes foram efetuados os testes de implantação do Dspace, configuração, desenho da nova arquitetura do banco de dados, compatibilização e criação de novos metadados, desenvolvimento de funcionalidades.

Na época, a produção científica contabilizada era de 19.200 itens. A migração gradual desses itens iniciou-se em julho de 2014.

Internamente, além de todas as funções inerentes e habituais a um repositório, o diferencial do RDI do IPEN diz respeito à integração com os dados registrados no sistema de informação gerencial e planejamento do instituto, o SIGEPI. Trata-se da uma funcionalidade especial, desenvolvida em ambiente externo ao Dspace, porém acrescentada no momento do registro do documento no Dspace via metadado específico, de tal forma que cada trabalho registrado no RD se correlaciona, automaticamente com a atividade do Plano Diretor à qual o autor do IPEN está vinculado.

Para essa finalidade foi efetuado um exaustivo trabalho de identificação dos nomes completos dos autores do IPEN (lista de autoridades), com as suas respectivas variáveis na forma de citação e agrupamento dos trabalhos. Foi atribuído um número único de identificação para cada autor, o ID autor IPEN, formato semelhante ao Researcher ID utilizado pela base internacional Web of Science. Essa facilidade constituiu um filtro que ao ser acionado reúne e apresenta rapidamente todos os trabalhos de um determinado autor.

Ao RDI está vinculada também uma tabela estatística, atualizada on-line a cada registro introduzido. Essa funcionalidade destina-se à obtenção de dados para a elaboração de índices e quadros estatísticos a serem confeccionados fora do ambiente do Dspace para subsidiar os pesquisadores e os gestores do IPEN, com informações para a monitoração, administração e elaboração de indicadores científicos fornecidos para o Plano Diretor do IPEN, o relatório anual da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior( CAPES) e outros, bem como para cumprir as exigências dos órgãos financiadores de pesquisa.

O modelo adotado para a coleta dos trabalhos também difere de outros. Nesta primeira etapa foi considerado mais conveniente o serviço de informação (biblioteca) responsabilizar-se pela coleta, depósito e complementação dos dados, utilizando as fontes de informação nacionais e internacionais. Assim, a unidade de informação realiza periodicamente a verificação dos trabalhos publicados pelos pesquisadores nas bases Web of Science, Scopus, Scielo, INIS e Currículo Lattes. Após a eliminação das duplicatas e localização dos documentos na íntegra efetua-se o depósito no RDI.

Trata-se de um modelo de depósito que esta sendo testado, há vantagens e desvantagens. A principal vantagem diz respeito à economia de tempo do pesquisador uma vez que se elimina a obrigatoriedade do autodeposito, tornando, porém, imprescindível por parte do pesquisador à atualização do seu Currículo Lattes. A maior desvantagem foi absorvida pela Biblioteca, qual seja a coleta periódica dos documentos publicados bem como a localização e obtenção da evidência dos mesmos.

Importante registrar que a construção do RD foi uma iniciativa muito nova na instituição, que demandou um trabalho detalhado, cuidadoso e gradual das equipes de desenvolvimento de sistemas e da biblioteca, dado a pouca familiaridade com a nova plataforma. Alia-se a esse fato a opção de utilizar um software livre, onde certas funcionalidades ainda não foram desenvolvidas.

Em setembro de 2014, após oito meses de trabalho, as equipes conseguiram migrar 23%, das coleções, foi uma tarefa que demandou ajustes, adequações, testes e decisões internas, dado o grande nível de detalhamento dos dados, motivo de comemoração das equipes, após cada etapa finalizada e bem sucedida. Contamos também com a assessoria de uma empresa especializada no assunto, a qual guiou a equipe da informática em cada funcionalidade desenvolvida. Nesse ritmo de trabalho, foi possível completar o processo de migração em fevereiro de 2015. Finalmente, em junho desse mesmo ano, o RDI foi disponibilizado na Internet.

2.2 Desempenho do RDI em 2015

Atualmente o novo RDI:

- dispõe de uma identidade própria e permanente, (ex: http://repositorio.ipen.br );

- utiliza as estatísticas de uso do Google Analytics;

- é reconhecido pelo Google Scholar e outras máquinas de busca da Internet;

- participa dos rankings internacionais de repositórios institucionais (Ex: Webometrics);

- tem registro nos Diretórios Internacionais de RIs (Ex. DOAR);

- interopera com sistemas congêneres.

Conforme foi mencionado, a criação do RDI e a migração dos dados constitui a primeira etapa dentro de um projeto maior, qual seja institucionalizar e operacionalizar a gestão da produção científica do IPEN. Após o processo se consolidar em entrar em rotina de funcionamento, as próximas etapas a serem desenvolvidas pelas equipes, dizem respeito à:

- automação da coleta dos documentos;

- otimização das ferramentas de busca;

- obtenção de relatórios estatísticos customizados;

- otimização do lay-out do RDI;

- acréscimo de novas coleções;

- desenvolvimento de novas funcionalidades.

A pesquisa no RDI é muito simples e segue os padrões da maioria das bases de dados. É possível pesquisar por autor, título, assunto, ID de autor IPEN, ano de publicação, combinar palavras- chave de busca e assim por diante. Apresenta também uma tabela estatística funcionando em tempo real, distribuída por nível monográfico; isso permite que a direção e o corpo técnico científico acompanhe a evolução quantitativa dos documentos depositados no RDI.

Uma das últimas funcionalidades acrescentadas ao RD, diz respeito à sinalização dos autores do IPEN. Ao clicar no símbolo do autor é possível acessar a página do pesquisador, onde se apresentam os seguintes dados: as variáveis do nome, uma tabela com todos os trabalhos constantes no RDI , bem como um quadro resumo numérico. Dessa forma o autor pode visualizar, acessar e monitorar à sua produção científica com o texto completo de forma rápida e simples . O quadro resumo se configura ainda como uma linha do tempo para o autor.

Por se constituir em um equipamento totalmente apoiado na tecnologia da informação, o RDI é um recurso institucional dinâmico sujeito a constantes atualizações e melhorias, o qual deve garantir a confiabilidade dos dados providos bem como assegurar a sua sustentabilidade.

3 Referências bibliográficas

BRASIL. Projeto de Lei do Senado 1120/2007 Dispõe sobre o processo de disseminação da produção técnico-científica pelas instituições de ensino superior no Brasil e dá outras providências. Diário oficial da Republica Federativa , Brasília, DF, Disponível em: http://www.camara.gov.br/sileg/integras/461698.pdf Acesso em: set. 2014.

INSTITUTO BRASILEIRO DE INFORMAÇÃO EM CIÊNCIA E TECNOLOGIA - IBICT Repositórios digitais. Site institucional. Brasília: 2009. Disponível em: http://www.ibict.br/informacao-para-ciencia-tecnologia-e-inovacao%20/repositorios-digitais Acesso em set. 2014.

KURAMOTO, H. Acesso livre: como tudo começou. Brasília, 2012. Blog. Disponível em: http://kuramoto.blog.br/2012/02/27/acesso-livre-como-tudo-comecou Acesso em: set. 2014.