Navegação Eventos - Resumos por ano de publicação "2018"

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  • IPEN-DOC 25470

    SOLANO, A. ; ARATA, A. ; LIMA, N.B. ; USSUI, V. ; LAZAR, D.R.R. . Y-TZP dental ceramics: Sintering process improvement using microwave energy. In: INTERNATIONAL CONGRESS ON CERAMICS, 7th; CONGRESSO BRASILEIRO DE CERÂMICA, 62., June 17-21, 2018, Foz do Iguaçu, PR. Abstract... 2018. p. 122-122.

    Abstract: Conventional sintering techniques of yttria-tetragonal zirconia polycrystals (Y-TZP) ceramics have presented limitations regarding the sintering time and temperature, increasing the cost of the final dental and biomedical products. Herein, microwave sintering comes to be an interesting alternative by providing fast heating, high densification and grain size control, decreasing the total time to produce the ceramic. The aim of this study was to compare the effect of microwave sintering of a pre-sintered commercial dental Y-TZP ceramic and a Y-TZP produced from powders synthesized in a laboratory scale by the copreciptation route. Densification, fracture toughness, grain size and crystalline phase quantification of sintered samples were evaluated. The synthetized and commercial (Vita Zahnfabrik, Germany) groups were submitted to 1450 °C and 1350 °C sintering temperature for 15, 30 and 60 minutes. Both groups sintered at 1450°C for 15 minutes and 30 minutes showed the higher densification results (98% concerning to theoretical density). All the samples sintered at 1350 °C achieved 96TD% independent of the sintering time. XRD quantitative phase analysis indicates that samples are formed by 89% tetragonal and 11% cubic phases (0,833 standard deviation), except for the group prepared from coprecipitated powders sintered at 1450oC for 30 minutes, that presented 79% and 21% of tetragonal and cubic phases, respectively. Therefore, microwave sintering allows the preparation of dense ceramics with high tetragonal phase content. The sintering time and temperature induced differences at the Y-TZP microstructure.

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  • IPEN-DOC 26039

    FRIMAIO, AUDREW ; NASCIMENTO, BRUNA C.; BARRIO, RAMON M.M.; CAMPOS, LETICIA L. ; COSTA, PAULO R.. X-ray spectrometry applied for determination of linear attenuation coefficient of tissue-equivalent materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 207-207.

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  • IPEN-DOC 25556

    GONÇALVES, G.M. ; LIMA, G.N.S. ; MACEDO, M.V. ; ORTIZ, N. . Water removal of oxytetracycline using titanium dioxide/solar photodecomposition and biocarbon adsorption. In: BIOCHAR, August 20-23, 2018, Wilmington, Delaware, USA. Abstract... 2018.

    Abstract: Oxytetracycline (OTC) is a broad-spectrum antibiotic with efficacy against infections, high solubility in water and used both in veterinary and human medicine, primarily in poultry and livestock, but also for human consumption. Nowadays Brazil is the higher protein producer in the world, and the agribusiness is the strongest economy sector in the country. The OTC use is increasing in veterinary medicine and also its detection in surface water resources and sewage treatment effluents. The conventional water treatment processes have to improve to enhance the pharmaceuticals removal efficiency. The occurrence of OTC in the natural environment can affect the selection of genetic variants of resistant microorganisms, inducing a risk to the ecosystem and human health. The experiments started with the dilution of standard oxytetracycline solution. They solutions were preheating before the addition of TiO2 and kept in a solar radiation chamber during 120 minutes. The addition of micronized biocarbon (diameter < 500 mesh) in all collected suspension aliquots followed by shaking, and centrifugation at 1500 rpm for 15 minutes allows the supernatants OCT measurements at UV – Visible Spectrophotometer Cary 13 at λ = 268 nm and 373 nm. The absorbance values were converted to antibiotics concentration using an analytical curve prepared with standard antibiotics solutions. After the processes optimization, the OCT removal percentage reached 95%with pseudo-second-order kinetics and better isotherm agreement with Langmuir R2= 0.689 and Redlich-Peterson with R2 = 0.738.

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  • IPEN-DOC 26032

    MATSUSHIMA, L.C.; VENEZIANI, G.R. ; SAKURABA, R.K.; CAMPOS, L.L. . Verification of absorbed doses using thermoluminescent detectors and mapping of isodose curves in IMRT planning. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 177-177.

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  • IPEN-DOC 25491

    ARAUJO, M.S. ; SILVA, A.C. ; SILVA, D.L.C. e ; MELLO-CASTANHO, S.R. . Variations of Qn distribution in bioactive glasses containing strontium oxide and alumina. In: INTERNATIONAL CONGRESS ON CERAMICS, 7th; CONGRESSO BRASILEIRO DE CERÂMICA, 62., June 17-21, 2018, Foz do Iguaçu, PR. Abstract... 2018. p. 857-857.

    Abstract: The complexity in designing brand-new compositions as 45S5 Bioglass® is mainly due to the fact the more components you have, the more difficult it is to trace the relationship between composition, structure and bioactivity. Also, the properties of bioactive compositions reflect their ability to release a critical amount of different ions in the surrounding host tissue, creating or not favorable conditions to stimulate cellular processes. Since these properties and process of interaction are directly related to the glass network connectivity, which can be evaluated by Qn distribution and other medium-range structural techniques, the present research studied two series of compositions based on 45S5 however adding amounts of Al2O3 and SrO, to verify the impact of subtle compositional changes in the Qn distribution. The samples were obtained by melting (1500°C) and quenching and characterized by X-ray diffraction (XRD), differential thermal analysis (ATD), Fourier transform infrared (FTIR) and Raman spectroscopy. The initial results indicates that the matrix of typical bioactive phospho-silicate glasses which consists to be mostly Q², with some Q³, structures have been maintained in samples containing only SrO (0-2,7%mol). However, the samples containing both Al2O3 (2%mol) and SrO (0-2,7%mol) indicates that the addition of 1%mol SrO there is an increase of Q² in detriment of Q³, but then when the addition is up to 2,7%mol there is a decrease of Q² inversely proportional to Q³. Although these changes have been presented, none of the samples of both series presented cytotoxicity. Furthermore, studies on biocompatibility are being conducted to evaluate its impacts on their bioactivity.

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  • IPEN-DOC 25368

    GOMES, M.P. ; SANTOS, I.P. ; REIS, L.A.M. ; COUTO, C.P. ; BETINI, E.G. ; MUCSI, C.S. ; COLOSIO, M.A.; ROSSI, J.L. . Valve seat insert: air quenching and characterization of components obtained with AISI M3:2 high-speed steel. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23., 04-08 de novembro, 2018, Foz do Iguaçu, PR. Resumo... 2018. p. 6228-6228.

    Abstract: The development of components ecologically correct is something more and more necessary. The first developement of valve seat inserts (VSI) take in account the use of cobalt and lead in its chemical composition. Such elements are avoided in the current applications due to its high cost and toxicological effects, respectively. In the present work was used VSI developed with a new chemical composition. The aim of this work were to air quench and characterize such components. The studied VSI were obtained with AISI M3:2 high-speed steel admixed with iron powder and another additives such as manganese sulphide, graphite, zinc stearate and carbides. All the air quenched VSI were double tempered, for one hour each, at seven equidistant temperature from 100 °C until 700 °C. The air quenched components had its mechanical and physical properties determined by means of its apparent density, apparent hardness and crush radial strength. The chemical composition was measured through the gases analyses and energy dispersive X-ray fluorescence spectrometry techniques. Microstructural and phase characterizations were performed with the support of optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. Regarding the VSI required properties, the best results were obtained with the components air quenched and double tempered at 600 °C.

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  • IPEN-DOC 25476

    BENTO, R.T. ; SZURKALO, M. ; OLIVEIRA, E.C. ; CORREA, O.V. ; PILLIS, M.F. . UV–Vis photocatalytic performance of the S-doped TiO2 and TiO2 thin films for water treatment. In: INTERNATIONAL CONGRESS ON CERAMICS, 7th; CONGRESSO BRASILEIRO DE CERÂMICA, 62., June 17-21, 2018, Foz do Iguaçu, PR. Abstract... 2018. p. 421-421.

    Abstract: TiO2 films have been widely used as catalysts in oxidative processes in order to degrade organic contaminant. However, without the presence of a dopant material, its photocatalytic activity is limited only in the region of ultraviolet radiation (UV), due to its high-energy band gap. In this present research, anatase TiO2 thin films were grown on borosilicate substrates by metalorganic chemical vapor deposition (MOCVD) at 400ºC. To make the semiconductor active in the visible light region, sulfur doped TiO2 films were prepared by means of a thermochemical treatment carried out in a tubular oven, under atmosphere of H2S at 50ºC for 60 minutes. The films were characterized by XRD, AFM, FE-SEM and XPS technique. The photocatalytic behavior of the films was evaluated by methyl orange dye degradation under UV-Vis irradiation for 300 minutes. The photocatalytic tests were realized in a reactor illuminated by two tubular UV lamps (352 nm), and in a reactor illuminated by visible light (400-700 nm) on different intensities, both containing 40 mL of the dye solution. The results showed that the S-TiO2 films present promising photocatalytic efficiency. Without the presence of the catalyst, there was no degradation of the methyl orange dye under UV-Vis irradiation. Non-doped TiO2 films do not exhibited photocatalytic activity under visible light. It was possible to observe that the visible light intensity influences the doped films photocatalytic performance.

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  • IPEN-DOC 25355

    CAMPOS, M.; OLZON-DIONYSIO, M.; SOUZA, S.D. de; MARTINEZ, L.G. ; MIRANDA, A.R.B.; DAVIM, J.P.. Uso da Radiação Síncrotron para estudo da fase austenita expandida em amostras de aço inoxidável ASTM F138 nitretadas em atmosferas de diferentes proporções de H2/N2. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23., 04-08 de novembro, 2018, Foz do Iguaçu, PR. Resumo... 2018. p. 5509-5509.

    Abstract: A nitretação a plasma é uma técnica de modificação superficial, que confere propriedades importantes ao material tratado, proporcionando melhores propriedades combinadas de resistência mecânica, ao desgaste e à corrosão. Essas melhoras estão atreladas à camada superficial formada, composta pelas fases ?N – uma fase metaestável conhecida como austenita supersaturada ou expandida, uma fase cúbica ?' ?(ou Fe4N) e outra hexagonal ? (ou Fe2-3N), entre outras menos comuns como os nitretos de cromo que aparecem em grande quantidade em altas temperaturas. A fase ?N demonstra ter boas propriedades mecânicas, tribológicas e de resistência à corrosão e vem sendo apontada como a principal fase responsável pela melhoria dessas propriedades nos aços nitretados. Porém os difratrogramas dessas fases ficam “mascarados” por outras fases formadas na superfície, que apresentam ângulos de difração próximos ao dela, além disso ela apresenta o segundo pico (200) com alargamento e deslocamento maior que os demais em relação à matriz. A natureza dessa estrutura cristalina ainda é uma incógnita, e várias estruturas já foram propostas. O objetivo desse trabalho e estudar a estrutura dessa fase em diferentes proporções do gás nitretante (H2/N2). Amostras de aço inoxidável ASTM F138 foram nitretados durante 4 horas, a uma temperatura de 400 ºC e uma pressão do gás nitretante de 6 Torr. A proporção do gás foi de 20/80, 40/60, 60/40 e 80/20 % de N2/H2. Os resultados mostraram que o tamanho da camada nitretada e a rugosidade da superfície nitretada aumenta com a concentração de nitrogênio. O coeficiente de atrito da superfície com o aço SAE 1050 das amostras nitretadas é estatisticamente igual ao da matriz (sem nitretação), com exceção da nitretada com maior concentração de nitrogênio, que teve um aumento de 20 %. Os difratrogramas síncrotron mostraram que para altas concentrações de nitrogênio o pico (200) ficou menos alargado e todos foram ajustados com duas estruturas diferentes, uma igual à matriz, cúbica de face centrada (CFC), com pequena distorções nos ângulos e outra com falha de empilhamento, para comparação. O processo de nitretação com maior concentração de nitrogênio parece ser uma ótima forma de ajudar a elucidar a estrutura da fase ?N.

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  • IPEN-DOC 25518

    WETTER, NIKLAUS U. ; JIMENEZ-VILLAR, ERNESTO . Ultra-high efficiency and low threshold in random lasers. In: LATIN AMERICA OPTICS AND PHOTONICS CONFERENCE, November 12-15, 2018, Lima, Peru. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: Random lasers hold the potential for cheap and coherent light sources, however, improvements in terms of efficiency and laser threshold are required. In this paper, we show two new strategies to increase efficiency and decrease the laser threshold.

    Palavras-Chave: lasers; randomness; nanoparticles; titanium oxides; solid state lasers; titanium compounds; rhodamines

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  • IPEN-DOC 25561

    SALES, T.S.N. ; BURIMOVA, A. ; CARBONARI, A.W. ; BOSCH-SANTOS, B. ; PEREIRA, L.F.D. . Tuning the dielectric response of HfO 2 nanoparticles by Si-doping. In: INTERNATIONAL SYMPOSIUM ON NANOPARTICLES-NANOMATERIALS AND APPLICATIONS, 3rd, January 22-25, 2018, Caparica, Portugal. Abstract... 2018.

    Abstract: The properties of bulk materials and corresponding nanostructures may differ significantly which leads to distinct scopes of their applications. As the miniaturization continues, nanostructures show great potential in microelectronics. Among others, nanostructured hafnium (IV) oxide (hafnia, HfO 2 ) has attracted considerable attention due to its chemical stability and physical characteristics 1 . It has high dielectric constant ( ∼ 25) and is relatively thermally stable (melting point at 3085 K) 2 . These qualities have made hafnia an alternative to SiO 2 for gate oxide layers in field-effect transistors, since the leakage current issue and consequent thickness limitations of silica were hindering miniaturization. Clearly, the features of HfO 2 can be further tuned by doping 3 . Understanding the relation between the macro-properties of such complex systems and their architecture at atomic scale should help select doping parameters adequate for particular applications. In this work 0at%, 5at% and 10at% Si-doped HfO 2 nanoparticles (NPs) were synthesized via sol-gel method. Basic characterization included scanning/transmission electron microscopy, electron backscattering and X-ray diffraction. NPs were demonstrated to have spherical shape, sizes in the range of 10─40nm and monoclinic structure (m-HfO 2 ). Local structure and electronic environment of the samples was probed with perturbed angular correlation (PAC) spectroscopy. Sample irradiation resulted in the formation of 181 Hf isotopes (PAC probes 4 ) at several sites whose decay to 181 Ta is preferentially through an intermediate (metastable) state with lifetime depending strongly on local extra-nuclear fields. Thus, time distribution of decay probability provided information on the ambient of the probe. For undoped sample PAC data has revealed two distinct Hf sites, one of those possessing well-defined quadrupole frequency ν Q ≈ 750 MHz and electric field distribution asymmetry η ≈ 0.36. Site occupation raised with temperature from 16% at T = 473K to 75% at T = 1073K, which agrees with the results found in the literature for the quadrupole interactions of 181 Ta in m-HfO 2 4 . For the doped samples (both Si 5at% and 10at%) additional site was observed. Symmetrical electric field distribution ( η = 0) and a greater site fraction at T = 673─873K allowed to attribute it to a tetragonal phase of hafnia. First principles analysis has shown that doping m-HfO 2 with certain cations can induce the formation of tetragonal phase 5 . We emphasize that this phase is desirable for transistor applications since it is associated with the highest dielectric constant.

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  • IPEN-DOC 25526

    BOIANI, NATHALIA F. ; GARCIA, VANESSA S.G. ; TOMINAGA, FLAVIO K. ; BORRELY, SUELI I. . Toxicidade do Propranolol (comercial versus manipulado), e de sua mistura com o cloridrato de fluoxetina, quando tratado por radiação ionizante. In: CONGRESSO BRASILEIRO DE ECOTOXICOLOGIA, 15., 01-04 de setembro, 2018, Aracaju, SE. Resumo expandido... 2018.

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  • IPEN-DOC 25531

    ASFORA, VIVIANE K.; ANTONIO, PATRICIA L. ; GONÇALVES, JOSEMARY A.C. ; BARROS, VINICIUS S.M. de; BUENO, CARMEN C. ; KHOURY, HELEN J.; CALDAS, LINDA V.E. . TL and OSL response of CaF2:Tm for electron beam radiation processing. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 303-303.

    Abstract: The use of electron beams for industrial applications has increased worldwide requiring accurate dosimetry systems to assure the quality of irradiated products. The radiochromic films and alanine/EPR dosimeters are often employed in electron beam radiation processing. The thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters are mainly used for the electron beam dosimetry for radiotherapy applications. The aim of this work is to study the TL and infrared stimulated luminescence (IRSL) response of the calcium fluoride dosimeter doped with thulium (CaF2:Tm) for electron beam radiation processing. The pellets of CaF2:Tm (6mm in diameter and 1mm thickness) were produced via the solution combustion synthesis technique at the Nuclear Energy Department - UFPE. The individual TL and OSL sensitivities of a bach of these dosimeters were previously evaluated and 50 pellets with a standard deviation of 6% were selected to be used in this study. Irradiation was performed at the Radiation Technology Center at IPEN-CNEN/SP using 1.5MeV electron beam from a DC 1500/25/4 – JOB 188 accelerator covering the dose rate range 2-32kGy/s and doses from 0.5kGy up to 10kGy. The TL and OSL readings were carried out after a preheating at 100°C during 15min using a Riso TL/OSL reader, model DA-20. The TL measurements were taken with a heating rate of 2°C/s, in the range from 50°C to 350°C. The OSL readings were carried out with infrared stimulation with optical power attenuated to 20% during 240s. Residual thermoluminescent glow curves for IRSL were recorded after stimulation times. The reproducibility and stability of the TL and IRSL responses were also evaluated, as well as the dependence with different dose rates from 2kGy/s up to 32kGy/s. The results showed a deconvoluted TL glow curve with four components, being the main two TL peaks centred in the regions of 150°C and 200°C. The area of the TL peaks increases linearly with the absorbed dose up to 6kGy for all the dose rates evaluated. For doses higher than 6kGy, the TL response is sublinear with saturation around 10kGy. The IRSL curves of the dosimeters present a fast and a slow decaying IRSL signals. The total area of IRSL curves were measured for both different doses and dose rates. The correspondent results were linearly dependent on the absorbed dose and saturated in almost 10kGy. The IRSL residual TL glow curves exhibited a symmetrical decrease to the growing OSL signal. All the results presented regarding TL and IRSL response of CaF2:Tm have shown that these dosimeters are suitable for electron beam dosimetry in radiation processing.

    Palavras-Chave: electron beams; thermoluminescence; radiations; calcium fluorides; electron dosimetry; thulium; doped materials

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  • IPEN-DOC 26047

    SILVA, A.M.B.; JUNOT, D.O. ; CALDAS, L.V.E. ; SOUZA, D.N.. TL and OSL characterization of CaSO4:Tb, CaSO4:Tb,Ag, and CaSO4:Tb,Ag(NP). In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 321-321.

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  • IPEN-DOC 27085

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

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

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  • IPEN-DOC 25343

    COUTO, C.P. ; COSTA, I. ; VIVEIROS, B.G. de ; ALENCAR, M.C. ; PANOSSIAN, Z.; ROSSI, J.L. ; COLOSIO, M.A.. The use of scanning vibrating electrode technique to evaluate the effect of hot stamping on corrosion resistance of press hardened steel 22MnB5 metallic coated with electroplated ZnNi. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23., 04-08 de novembro, 2018, Foz do Iguaçu, PR. Resumo... 2018. p. 5149-5149.

    Abstract: The carmakers and all their production chain must achieve worldwide targets of lightweight, safety and reduced fuel consumption. The use of ultra high strength steel, such as press-hardened steels (PHS), in vehicle structures has been contributing with this. This type of steel is widely used in hot stamping process, which consists in heating the steel blank to the total austenitization temperature, and then transferring it from the furnace into the die where the steel is deformed and quenched at the same time, with a minimum cooling rate of 27 K/s. The boron-manganese PHS steel comprises perlite and ferrite microstructure, and its tensile strength is around 600 MPa in the annealed condition. Thus, after the hot stamping process the PHS microstructure completely changes to martensite and the tensile strength increases to 1500 MPa or more. The transferring step is a critical one, due to the contact of the hot steel blank with the atmospheric air; as consequence, it causes the steel oxidation. To avoid that, the steel is protected with metallic coatings. The hot-dip AlSi is the most currently used coating for this application, however, in order to keep up with the high PHS demand, alternative coatings, like zinc-base is under investigation. This work had the objective of evaluating the corrosion resistance of PHS, 22MnB5 grade, coated with electroplated ZnNi before and after hot stamping, using scanning vibrating electrode technique (SVET). The corrosion-localized techniques are more suitable, once the results showed that after hot stamping the coating layer changes completely, as a result of chemical elements diffusion. Thus, different phases of Zn-Fe-Ni are formed and random distributed which impacts the corrosion resistance of the steel.

    Palavras-Chave: corrosion resistance; surface coating; steels; ferrite; scanning electron microscopy; perlite; hardening; pressing; zinc; nickel; coatings

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  • IPEN-DOC 25601

    ANA, PATRICIA A.; SILVA, ELIZABETE dos S.F.; BENETTI, CAROLINA; AMARAL, MARCELO M. ; ZEZELL, DENISE M. ; GOMES, ANDERSON S.L.. The use of optical coherence tomography for the evaluation of the effects of an infrared laser on dentin demineralization. In: BIOPHOTONICS CONGRESS: BIOMEDICAL OPTICS, April 3-6, 2018, Hollywood, Florida, USA. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: The effect of Er,Cr:YSGG laser on dentin demineralization was evaluated by optical coherence tomography, which was able to quantify and to evidence that this laser is a promissory alternative for preventing dentin caries.

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  • IPEN-DOC 25426

    MATOS, B.R. ; REY, J.F.Q.; MERINO, D.H.; SILVA, J.S. da ; SCHADE, U.; PUSKAR, L.; FONSECA, F.C. . The relation between the alpha/beta relaxation dynamics and the shape of ionomer building blocks. In: CONGRESSO BRASILEIRO DE ENGENHARIA E CIÊNCIA DOS MATERIAIS, 23., 04-08 de novembro, 2018, Foz do Iguaçu, PR. Resumo... 2018. p. 8629-8629.

    Abstract: The relation between the alpha/beta relaxations and the shape of the building blocks of ionomer materials is a key factor for programming an important temperaturedependent property: the memory of shape [1,2,3]. However, the morphology of ionomers is indirectly obtained via modeling of small angle X-ray scattering (SAXS) data owing to the hardly accessible image characterization of the nanometric building blocks - micelle-like cylindrical polymeric aggregates (radius ~ 2 - 6 nm and length > 100 nm) [3]. Herein, broadband dielectric spectroscopy (BDS) measurements, free from electrode polarization effects, allowed identifying the time and temperature dependence of the polarization of different length scales of the ionomer matrix, and more importantly, by directly providing the aspect ratio of the radius and length of the polymeric aggregates for each desired temperature. This finding is essential for controlling the shape of ionomer based functional products under several stimuli conditions, thereby advancing remarkable applications, such as four dimensional (4D) printing and polymer electrolyte fuel cells.

    Palavras-Chave: building materials; relaxation; scattering; temperature dependence; electrolytic cells; spectroscopy

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  • IPEN-DOC 25475

    SHINZATO, M.C.; ALMEIDA, T.M.; GUEDES-SILVA, C.C. ; SILVA, E.F.S.. The potential use of the alkaline waste from the aluminum industry as aluminum and silicon source in the geopolymerization process. In: INTERNATIONAL CONGRESS ON CERAMICS, 7th; CONGRESSO BRASILEIRO DE CERÂMICA, 62., June 17-21, 2018, Foz do Iguaçu, PR. Abstract... 2018. p. 353-353.

    Abstract: The objective of this work was to evaluate the alkaline waste of the aluminum industry (red mud) as a source of aluminum and silicon in the production of geopolymers. These elements are essential to form the tetrahedrally coordinated structures of the geopolymers. The characteristics of the studied material were compared with those of metakaolinite, since the latter is considered an excellent geopolymer precursor material. Samples of the dehydrated red mud were supplied by a Brazilian primary aluminum industry. This material was chemically (X-ray fluorescence) and mineralogically (X-ray diffraction) characterized. Samples of metakaolinite and red mud (original and pretreated by heating at 700 oC/2 h) were subjected to a leaching test with a 12 mol L-1 NaOH solution to determine the contents of reactive silica and alumina fractions. The Si4+ and Al3+ contents of the filtered solutions were determined by plasma optical emission spectrometry. The red mud has a total of 21.7% Al2O3 and 16.6% SiO2, and it is composed by the mineral phases: quartz, hematite, kaolinite, goethite, gibbsite, anatase, sodalite, gypsum. The contents of the leached fractions of Al3+ and Si4+ of the original red mud were respectively 3.9% and 0.7%. The red mud heated sample presented higher contents of Al3+ (8.5%) and Si4+ (6.6%). It was verified that the heating process increased the concentrations of Al and Si fractions available for the geopolymerization reactions. These values are closer to those obtained for metakaolinite (9.2% Al3+ and 4.4 Si4+). The X-ray diffraction data of the heated red mud revealed that the hydroxylated phases became amorphous and promoted the formation of metakaolinite. Thus, the red mud has important components, which when heated, increase the Al and Si availability for the geopolymerization reactions. The other components of the red mud, being less reactive, serve as aggregates for the geopolymer composition.

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  • IPEN-DOC 25905

    CAVALCANTI, H. de S. ; MIURA, VIVIANI M. ; ZAMBONI, CIBELE B. ; SILVA, DALTON G.N. da ; AZEVEDO, MARIA R.. The potassium reference value in blood in inhabitants of Brazil using EDXRF technique. In: BRAZILIAN MEETING ON NUCLEAR PHYSICS, 41th, September 2-6, 2018, Maresias, SP. Abstract... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: In this investigation, we intend to determine potassium levels in human blood aiming to study in more details the common de¯ciencies in Brazilian population helping their diagnostic well as to facilitate the interpretation of data deriving from clinical practice. The potassium takes part in the human being metabolism and it is very important for preservation of the osmotic and acid-base equilibria of human °uids, so its variations are generally associated to pathological processes. The objective of this study is the establishment of reliable potassium reference value in blood, using EDXRF technique, with emphasis on the statistical treatment. The samples came from Blood Banks from di®erent parts of Brazil. The biological samples were obtained from a select healthy group (male and female blood donors), following the procedure conventionally establish for blood donation. The in°uence of sex and age was evaluated considering several range for age (18-20, 21-30, 31-40, 41-50, 3 51 years). The result is presented following a descriptive statistics procedure, which includes the evaluation of mean, standard deviation, median and mode. This statistical treatment make possible the comparison with data derived for di®erent population groups. These results show small di®erences when a comparison is performed in function of age and sex emphasizing the necessity to adopt ranges.

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  • IPEN-DOC 26045

    JUNOT, DANILO O. ; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . The influence of the preparation route in the TL/OSL signal of CaSO4:Eu,Ag samples. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 310-310.

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

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

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