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  • IPEN-DOC 27101

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

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  • IPEN-DOC 27100

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

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  • IPEN-DOC 27099

    OSTERMANN, CAROLINE ; ZANNONI, NORA; CARVALHO, ELIAS ; NOVAES, MARIANA ; WILLIAMS, JONATHAN; VEGA, OSCAR . Exploring chiral BVOCs in Amazon and Atlantic forest by TENAX® and Carbograph® sorbent. In: LATIN AMERICAN SYMPOSIUM ON ENVIRONMENTAL ANALYTICAL CHEMISTRY, 14th; ENCONTRO NACIONAL DE QUÍMICA AMBIENTAL, 9.; WORKSHOP EM AVANÇOS RECENTES NO PREPARO DE AMOSTRAS, 12.; SEMINÁRIO CORSAN DE PESQUISA E INOVAÇÃO, 2., November 6-8, 2019, Bento Gonçalves, RS. Poster... 2019.

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  • IPEN-DOC 27098

    NAKANO, V.E.; OSSUGUI, M.; FERREIRA, C.P.; SANTA CRUZ, L.M.; COSTA, A.R.; KIMURA, I.A.; BUSTILLOS, J.O.W.V. ; ALABURDA, J.. Método multirresíduo de agrotóxicos em água destinada ao consumo humano por LC-HRMS (ORBITRAP™). In: LATIN AMERICAN SYMPOSIUM ON ENVIRONMENTAL ANALYTICAL CHEMISTRY, 14th; ENCONTRO NACIONAL DE QUÍMICA AMBIENTAL, 9.; WORKSHOP EM AVANÇOS RECENTES NO PREPARO DE AMOSTRAS, 12.; SEMINÁRIO CORSAN DE PESQUISA E INOVAÇÃO, 2., November 6-8, 2019, Bento Gonçalves, RS. Abstract... 2019.

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

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  • IPEN-DOC 27097

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

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

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  • IPEN-DOC 27096

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

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

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  • IPEN-DOC 27095

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

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

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  • IPEN-DOC 27094

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

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

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  • IPEN-DOC 27093

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

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

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  • IPEN-DOC 27092

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

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

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  • IPEN-DOC 27091

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

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

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  • IPEN-DOC 27090

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

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

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  • IPEN-DOC 27089

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

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

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  • IPEN-DOC 27088

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

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

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  • IPEN-DOC 27087

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

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

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  • IPEN-DOC 27086

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

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

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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 27084

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

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

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  • IPEN-DOC 27082

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

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  • IPEN-DOC 27081

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

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  • IPEN-DOC 27078

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

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

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  • IPEN-DOC 27077

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

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

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  • IPEN-DOC 27076

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

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

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  • IPEN-DOC 27075

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

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

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  • IPEN-DOC 27074

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

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

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  • IPEN-DOC 27073

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

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

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  • IPEN-DOC 27072

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

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

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  • IPEN-DOC 27066

    MATOS, BRUNO R. ; MORAES, LETICIA P.R. ; SANTIAGO, ELISABETE I. ; FONSECA, FABIO C. . Synthesis and proton conductivity of Nafion with addition of CsHSO4. In: INTERNATIONAL CONFERENCE ON ADVANCED ENERGY MATERIALS, 1st; INTERNATIONAL CONFERENCE ON ADVANCED NANOMATERIALS, 8th; INTERNATIONAL CONFERENCE ON HYDROGEN ENERGY, 2nd, September 12-14, 2016, Guildford, England. Abstract... 2016. p. 53-53.

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  • IPEN-DOC 27065

    COSTA, PRISCILA ; RAELE, MARCUS P. ; YORIYAZ, HELIO ; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. . Modelling a prototype of thermal neutron detector using a thin boron film and a photodiode. In: ENCONTRO DE FÍSICA; ENCONTRO NACIONAL DE FÍSICA DA MATÉRIA CONDENSADA, 39.; REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 39.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 37.; ENCONTRO BRASILEIRO DE FÍSICA DOS PLASMAS, 13.; ENCONTRO DE PESQUISA EM ENSINO DE FÍSICA, 16., 3-7 de setembro, 2016, Natal, RN. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2016.

    Abstract: Neutron detection is an important task especially for worker protection in nuclear installations. For that purpose, it is desired to have portable and compact detectors, an aim which can be achieved using semiconductor detectors. In this work the Monte Carlo modelling of a neutron detector based on a thin boron film and photodiode is presented. The simulation was carried out using the MCNP6 code, in order to evaluate the detection efficiency for the alpha particles emitted in the boron neutron capture reaction. Two different setup subsets were modelled, taking into account the fact that the film could be deposited either in direct contact to the photodiode surface, or in indirect contact, where the film was deposited in a substrate (glass). In direct contact the thin film thickness ranged from 0 to 5 μm. For the indirect contact the thicknesses of the substrate and air region were varied. For both cases, the model was also prepared to consider the situation in which the film was sandwiched between two photodiodes in order to increase alpha particle detection efficiency. The results show that the thickness of the substrate, of 150 μm or 1000 μm, has a small influence on the alpha particle flux on the photodiode surface. The increase of the air region causes a decrease of 57 % in the flux of alpha particles in the photodiode. These different setups allowed determining the thickness values of thin boron film that delivers a higher alpha particle flux, which will lead to an optimum detection efficiency.

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  • IPEN-DOC 27032

    BAPTISTA, M.S.; CADET, J.; DI MASCIO, P.; GHOGARE, A.A.; GREER, A.; HAMBLIN, M.R.; LORENTE, C.; RIBEIRO, M.S. ; THOMAS, A.; VIGNONI, M.. Guidelines for defining type I and II photosensitized oxidation. In: ASP CONFERENCE, May 21-26, 2016, Tampa, FL, USA. Abstract... Herndon, VA, USA: American Society for Photobiology, 2016.

    Abstract: Here, ten tips are presented for a standardized definition of type I and II photosensitized oxidation reactions. Because of varied notions of photosensitized oxidation reactions, a checklist of recommendations is provided for their definitions. Type I and type II reactions are oxygen-dependent and involve unstable species such as peroxyl radical and singlet oxygen. This exercise was an outgrowth of a mini-symposium on singlet oxygen chemistry in Cambury, Brazil in 2014.

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  • IPEN-DOC 27022

    RICCIARDI, R.I. ; BARROSO, A.C.O. ; ERMINE, J.L.. Metodologia para o alinhamento estratégico da gestão do conhecimento: uma aplicação em um centro de Radiofarmácia. In: GIRONZINI, EDUARDO M. (Ed.) SIMPOSIO INTERNACIONAL SOBRE EDUCACIÓN, CAPACITACIÓN Y GESTIÓN DEL CONOCIMIENTO EN ENERGÍA NUCLEAR Y SUS APLICACIONES, November 22-26, 2015, Cusco, Peru. Abstract... Lima, Peru: Sociedad Peruana de Radioproteccion, 2015. p. 72-73.

    Abstract: Introdução: A grande preocupação da Gestão do Conhecimento é o emprego de técnicas para que as empresas captem os conhecimentos necessários para seus trabalhos operacionais; desse ponto de vista, a visão operacional somente pode ser percebida entre os trabalhadores, orientada segundo seus interesses e vai elucidar a percepção do estado crítico dos conhecimentos e dos porquês. Também, a Gestão do Conhecimento deve estar alinhada com os objetivos e metas estratégicas da organização; desse ponto de vista, é necessário entender claramente a estratégia organizacional, que dará uma percepção dos conhecimentos estratégicos relevantes para atingir suas metas. Essa visão gerencial é alcançada com seus dirigentes, aqueles que planejam e formulam a estratégia. A presente metodologia proporciona uma visão bastante consistente e agregada, onde toda a organização é representada, sob o ponto de vista das duas visões, operacional e gerencial, confrontando-as para se obter uma visão mediana, assim, assegurar o alcance das metas e futuro em consenso com as tarefas operacionais. Material e Métodos: A metodologia mostra uma integração inovadora de 6 processos: identifi cação dos conhecimentos através de análise dos processos; reconfi guração dos conhecimentos em domínio e sua representação em mapas; análise critica do conhecimento envolvendo importância e vulnerabilidade; análise estratégica do conhecimento e sua representação em mapas; combinação e comparação das análises critica e estratégica e sugestão de ações. Esta metodologia foi aplicada no Centro de Radiofarmácia do IPEN (Instituto de Pesquisas Energéticas e Nucleares), através de questionários, entrevistas e observação, utilizando os métodos de análise quantitativa e qualitativa. Resultados e Discussão: Nós encontramos 56 conhecimentos críticos, 64 conhecimentos estratégicos e críticos, em um total de 211 conhecimentos; além de 20 conhecimentos estratégicos inexistentes. Conclusões: as razões das criticidades dos conhecimentos proporcionaram informações concretas para a sugestão das ações, a relevância estratégica e os níveis de criticidade indicaram a prioridade das ações.

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  • IPEN-DOC 27037

    ROSTELATO, MARIA E.C.M. ; SOUZA, CARLA D. de ; SOUZA, DAIANE C.B. de ; ZEITUNI, CARLOS A. ; TIEZZI, RODRIGO ; COSTA, OSVALDO L. da ; RODRIGUES, BRUNA T. ; MOURA, JOÃO A. ; FEHER, ANSELMO ; SORGATTI, ANDERSON ; MOURA, EDUARDO S. de ; MARQUES, JOSE R. de O. ; SANTOS, RAFAEL M. dos ; KARAM JUNIOR, DIB. Waste management protocols for Iridium-192 sources production laboratory used in cancer treatment. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 2038-2038.

    Abstract: Introduction: Brachytherapy is a form of treatment that uses radioactive seeds placed in contact or inside the region to be treated, maximizing the radiation dose inside the targeted areas. Iridium-192 is being used in brachytherapy since 1955. It presents emission energy in the “therapy region” (370keV) and is easily produced in a nuclear reactor (191Ir (n, γ) → 192Ir). Wires are an iridium-platinum alloy with 0.36 mm diameter and they can be cut in any needed length. They can be used in several types of cancer. The linear activity is between 1 mCi/cm (37 MBq/cm) and 4 mCi/cm (148 MBq/cm) with variations of 10% in 50 cm maximum. This activity values classified the treatment and low dose rate (0,4 à 2 Gy/h). The propose of this work is to present a waste management system in a cancer treatment radioactive sources production laboratory. Methodology and Results: The solid waste is previously characterized in the analysis phase. The contaminants are already known and they are insignificant due to their fast half- life. The iridium-192 half-life is 74.2 days, classified as very short half-life waste. The waste activity is adds to 8mCi (2.96x108 Bq) per wire. According to the CNEN-NN 6.08 standard, that presents the discharge levels, the limit is 1 kBq.kg-1 (2.7x10-5 mCi.kg-1). The radioactive waste generated during the I192 wires production has a weakly activity of 9.7 GBq.g-1. According to the standards, this activity is too high to be discarded into the environment. The waste must be managed following the ALARA principal using the R&R (retain e retard) system, that means, temporary storage and posterior discharge. Since every 4 months, maintenance is performed inside the hot cell used for production, the waste must be removed. Using the equation: 𝐴 = 𝐿 λ (1 − 𝑒−λt), the total calculated activity is 1.68 x 1016 Bq and 4.8 g mass at the end of each 4 months period. This amount is stored inside a shielding device that has 212.37 cm3 volume. The waste will take 9.8 years (calculated by 𝐴 = 𝐴0(𝑒−λt)) to decay to the discharge levels. To store 30 devices during 10 years, a space with 6,370 cm3 is necessary. The laboratory has enough space for this storage. Thus, the radioactive waste management can be performed through the R&R (retain and retard) system safely.

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  • IPEN-DOC 27035

    TEIXEIRA, MARIA I. ; CALDAS, LINDA V.E. . Optical stimulated luminescence from citrine for high-doses dosimetry. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 1343-1343.

    Abstract: In the sterilization of medical and pharmaceutical products, food and flower preservation, and treatment of electrical cables and al-treatments of different materials is used the irradiation process by highdoses because it presents advantages varies.Several Brazilian stone samples were already studied at IPEN for use in radiation dosimetry, using the techniques of thermoluminescence (TL), optical absorption (AO) and optically stimulated luminescence (OSL). Different kinds of glasses and sand from Brazilian beaches were studied at IPEN and showed favorable characteristics for their use for high-dose dosimetry. The possibility of using semi-precious stones from Brazilian as topaz, amethyst and jasper, and jade samples from different parts of the world, have been studied and tested at IPEN, using the technique of thermoluminescence. The objective of this work was to study citrine samples for application in high-dose dosimetry, using the OSL technique. The thermal treatment for reutilization of the materials was 300oC during 1h in an unsealed oven. The samples were irradiated using a Gamma Cell-220 system of 60Co (dose rate of 1.47 kGy/h), with doses from 50 Gy up to 300 kGy. The reproducibility of the OSL response presented a maximum variation coefficient of 5.7%. The lower detection limit was obtained as 350 mGy for the citrine pellets. The results show that the OSL detectors based on citrine may be useful for high-dose dosimetry in industrial processes and in the sterilization process of materials in hospitals.

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  • IPEN-DOC 27011

    KUAHARA, LILIAN ; CORREA, EDUARDO ; POTIENS, MARIA da P. . Activimeter response behaviour analysis related to well depth. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 756-756.

    Abstract: The activimeter, instrument used to radionuclide activity measure, consist primarily of a well type ionization chamber coupled to a special electronic device. Its response, after calibration, is shown in units of the activity quantity (Becquerel or Curie). It also has a special holder designed to accommodate all kinds of syringes and vials containing the radiopharmaceuticals. Many factors influence the response of an activimeter such as the volume of the sample, its position inside the activimeter well and the geometry of the vials. The idea of this study is to find the better position inside the well to get the best activity values, positioning the holder in different profundity, simulating a clinical procedure. The reference activimeter used was the Secondary Standard NPL-CRC radionuclide calibrator, traceable to the National Physical Laboratory (NPL), England, taking as reference the depth of 400 mm. Two other activimeters were tested: Capintec, CRC-15BT model with the depth of 170 mm and one CRC-25R model with depth of 257 mm. They all belong to the Instrument Calibration Laboratory of IPEN, São Paulo, Brazil. The measurements were made using three radioactive check sources: Co-57, Ba-133 and Cs-137. Sources readings were taken at various depths inside the ionization chamber well. The results shown maximum variation of 14.28% for Co-57, 11.27% to Ba-133 and 8.8% to Cs-137. All measurements were compared with those values found for the reference depth in each activimeter. The variation found show the necessity of include this kind of determination in all quality control programs that are applied to an activimeter used by a Nuclear Medicine Service.

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  • IPEN-DOC 27010

    POTIENS JUNIOR, ADEMAR ; COSTA, NATHALIA ; CORREA, EDUARDO ; SANTOS, LUCAS ; VIVOLO, VITOR ; POTIENS, MARIA da P. . Tandem KAP meters calibration parameters by Monte Carlo Simulation using reference RQR radiation qualities. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 702-702.

    Abstract: The Kerma-area product quantity can be obtained by measurements carried out with a kerma-area product meter (KAP) with a plane-parallel transmission ionization chamber mounted on the X ray system. It is the integral of the air kerma over the area of the X ray beam in a plane perpendicular to the beam axis. This quantity has been important to establish the diagnostic reference levels (DRLs) all over the word. In this work the MCNP5 code was used to calculate the imparted energy in the air cavity of KAP meter and the spatial distribution of the air collision kerma in entrance plan of the KAP meter. From these data, the air kerma-area product (KAP) and the calibration coefficient for the KAP meter were calculated and compared with those obtained experimentally. The X-ray tube was easily modelled as well the complete tandem calibration set up was possible. The spectra of the diagnostic radiology RQR reference qualities measured were used as a source definition in the input card for the Monte Carlo simulation. The clinical KAP meter calibration coefficients were obtained experimentally and by Monte Carlo simulation. The differences between those values were about 2%, except for RQR 10 (5.45%). The uncertainties in Monte Carlo simulation were less than 0.5% in all cases and the FOM (Figure of Merit) was constant for a number of histories of 1 million.

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  • IPEN-DOC 27064

    SAHYUN, ADELIA ; GHOBRIL, CARLOS N.; PEREZ, CLARICE F.; SORDI, GIAN M. . The evaluation of the real alpha value in Brazil and its projection until the year 2050. In: CLEMENT, CHRISTOPHER (Ed.); VALENTIN, JACK (Ed.); OGINO, HARUYUKI (Ed.); FOOTE, DEVON (Ed.); REYJAL, JULIE (Ed.); OMAR-NAZIR, LAILA (Ed.) INTERNATIONAL CONGRESS OF THE INTERNATIONAL RADIATION PROTECTION ASSOCIATION, 14th, May 9-13, 2016, Cape Town, South Africa. Abstract... The International Radiation Protection Association, 2016. p. 444-444.

    Abstract: The real evolution of the alpha value in Brazil has been performed three times in 1993 and 2000 making use of the procedure advised by ICRP and in 2004 making use of the procedure recommended by the IAEA. In both, the first two papers were made various projections for the coming years until 2025. Because of the great social and economic crisis in which the country (Brazil) is going, we decided to reassess the alpha value of our country and compare it with the projections of the two previous papers. Therefor e, we decided to make a dollar correction from that time to the current dollar, comparing the purchasing power from that time to the current. This procedure has shown us the great gap of value in use and that the actual value should be two to three times h igher. By GDP per capita, we could calculate the alpha value updated to various countries including the European Union and compare them with the official value currently in use. In conclusion, we believe that all countries that adopt an alpha value should upgrade it to the present day.

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  • IPEN-DOC 27059

    GARCIA, V. ; SOLE, S.V. ; BOIANI, N.F. ; ROSA, J.M.; BORRELY, S.I. . Evaluation of toxicity and color reduction of Reactive dye Yellow 160 and Red BG-3B, and textiles effluents after treatment by electron beam. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 110-110.

    Abstract: Textile effluents are always collored due to the amount of dyes lost during dieying processes. The low biodegradability and high solubility makes these compounds (reactive dyes) difficult to be enough removed by conventional treatment processes. The objective of the present study is to assess toxicity of Reactive dye Yellow - 160 and Red BG-3B as well as raw effluents containing such dyes. Acute toxicity tests were carried out with reference aquatic organisms: Vibrio fischeri bacteria and Daphnia similis microcrustaceans. After this, the effluent is also submitted to EBI treatment (irradiation at electron beam accelerator) for reducing color, with 0.5 kGy to 20 kGy doses. 100% of daphnids survived at 1g.L-1 of RY-160, and for Red BG-3B (C=0.564 g.L-1) EC 50% (48h) = 69.0 ± 0.66 . Raw textile effluent with dye RY-160 resulted in EC 50% lower than 2% for both organisms (D. similis EC 50% (48h) = 1.74 ± 0.53 and 0.6 ± 0.29, V. fischeri (15 min). For raw textile with Red BG-3B: D. similis EC 50% (48h) = 6.73 ± 0.72. The EBI treatment was effective for color removal, efficiency superior to 90% at 10 kGy. The data demonstrated the importance of evaluating not only dyes but also the effluent, since it has several additives that contributed to the high toxicity.

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  • IPEN-DOC 27058

    MARTINI, G. ; VIVEIROS, W.; FRANÇA, D.D.; QUINAGLIA, G.; RAIMUNDO, C.C.; LOPES-FERREIRA, M.V.; ROGERO, S.O. ; ROGERO, J.R. . Fish Embryo Toxicity Test (FET) to evaluate atrazine effects. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 83-83.

    Abstract: Surface water samples from São Paulo state were collected to perform Bioluminescent Yeast Estrogen Screen (BLYES) and chemical analyses (LC-MS/MS). Results showed environmental concentrations of atrazine from 2 to 43 ng L-1 on chemical analyses. Some studies have been performed to evaluate toxic effects on non-target organisms (fish) using herbicides such as Atrazine, a moderately toxic compound classified as an endocrine disrupting chemical (EDC) that can affect reproduction of several aquatic organisms with a compromise of vitellogenin production. To determine toxicity on embryonic stages of fish to different environmental chemicals and waste water, Fish Embryo Toxicity Test (FET) was designed using Danio rerio as model specie on this test, according to OECD 236 or ISO 15088 protocols, however these protocols observe only acute toxicity based on endpoints such as coagulated eggs, nondetachment of the tail, lack of heart beating and lack of somite formation. Some abnormalities can be recorded after the exposure on FET test but they are not considered as endpoint, neither any other compromised biomarker by EDC action. In order to evaluate the possibility of using these chronic endpoints and to verify if those environmental concentrations of atrazine are ecologically relevant, compromising reproductive aspects, FET test using Danio rerio were performed to assess lethal concentrations, sublethal concentrations and vitellogenin quantification after atrazine exposure. Occurrence of morphological abnormalities (microcephaly, spine curvature, edema, reduced size) and mortality of the embryos were determined exposing 20 fertilized eggs to atrazine concentrations from 2 to 64 mg L-1. The LC50 and EC50 were obtained after 96 hours of exposure. Organisms that survived each concentration were frozen to further vitellogenin quantification. Preliminary average concentrations obtained (LC 50; 96h= 48.15 mg L-1 and EC 50; 96h= 27 mg L-1) were considerably higher than concentrations observed on environmental samples. Therefore, surface water concentrations would not cause mortality or deformity in fish emphasizing the necessity to observe possible effect on vitellogenin concentration. Data will be analyzed and compared with the environmental concentration of atrazine to stablish the potential application of vitellogenin as endpoint on FET test.

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  • IPEN-DOC 27056

    GIMILIANI, G.T. ; FONTES, R.F.; ABESSA, D.M.. Modeling the dispersion of endocrine disruptors in the Santos Estuarine System (São Paulo State, Brazil). In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 64-64.

    Abstract: Estrogens are hormones responsible for growth and reproduction. They are naturally synthesized by animals and humans alike. Xenoestrogens are identical to natural hormones, but they are manmade and used as oral contraceptives. Xenoestrogens are a specific group of drugs found in domestic wastewater and some environmental matrices. These compounds remain after conventional sewage treatment and, consequently, affect both the environment and non-target aquatic organisms. In this study, we used the Delft3D hydrodynamic model to estimate the amount of both natural and synthetic estrogens that have been released in the Estuarine System of Santos and São Vicente and the Santos Bay. The data on flow from the sewage treatment plants and on average concentrations of natural and synthetic estrogens released in aquatic environments were obtained from the literature. The results of the modeling showed higher concentrations of estrogens in the estuarine waters of the Largo Pompeba region, the São Vicente Canal, and the Santos Bay, which are regions that receive greater inflows of domestic sewage. The results also suggest that higher concentrations of estrogenic compounds are expected to be found in areas with higher levels of salinity.

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  • IPEN-DOC 27055

    CUNICO, P.; FUNGARO, D.A. ; KUMAR, A.. Toxicity studies applied to evaluate the modified zeolites adsorbent for treating copper-complex dyes from simulated dyehouse wastewater. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 35-36.

    Abstract: Textile dyes occur in wastewaters in different concentrations due to their poor fixation to fabrics. Even at low concentrations, textile dyes can cause waste streams to become highly colored. Aside from their negative aesthetic effects, certain textile dyes have been shown to be toxic, and in some cases, these compounds are carcinogenic and mutagenic. Zeolite synthesized from fly and bottom ashes and modified with hexadecyltrimethylamonium (ZMF and ZMB, respectively) were used as adsorbent to remove dyes - Solophenyl Navy and Solophenyl Turquoise and their hydrolyzed forms Solophenyl Navy Hydrolyzed and Solophenyl Turquoise Hydrolyzed, respectively, from simulated textile wastewater. The purpose of the research was to use bioassays with Lemna minor, Ceriodaphnia dubia and Chironomus tepperi to determine the acute and chronic toxicity of these dyes before and after adsorption process. The acute results indicated C. tepperi showed to be less sensitive when compared with other test organisms, showing values of 48hLC50 70.8 and 211 mgL-1 for SN and ST. On the other hand, C. dubia showed to be very sensitive to the dyes tested (48hLC50 1.25; 54.5; 0.78 and 2.56 mgL-1 for SN, ST, SNH and STH), while L. minor presented response for higher concentration of the dyes, as chlorosis, loss of roots, reduction of the size and etc., showing values of EC50 of 18.9; 69.4; 10.9 and 70.9 mgL-1 for SN, ST, SNH and STH). Chronic tests with C. tepperi showed changes in survival, growth, development and gender differences for SN and ST dyes. After adsorption treatment with ZMF the acute effects were substantially reduced for both dyes and their hydrolyzed forms, showing absence of toxicity after treatment. However, the treatment with ZMB showed no difference and/or increased toxicity in some cases. Toxicity Identification Evaluation testes were realized and showed the baseline acute effects were substantially reduced after treatment with Ethylenediaminetetraacetic acid, showing the most of the toxicants in this study are cations metals. These experimental results suggest both dyes, raw and hydrolyzed, are toxic and their removal are necessary.

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  • IPEN-DOC 27054

    FERNANDES, I.; SOUSA, E.P.; GASPARRO, M.R.; CATHARINO, M.G. ; CERAVOLO, M.; CAMARGO, J.; LINS, C.G.. Sensitivity of Nitokra sp copepod exposed to UVA and UVB filters used in commercial formulations. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 65-66.

    Abstract: Large discharges of pollutants released in the marine environment have as final destination the sediment, affecting the quality and biodiversity. Pharmaceuticals and personal care products (PPCPs) are lipophilic and poorly biodegradable, with potential for bioaccumulation and persistence in the environment. Compounds from commercial sunscreens are found in the oceans, because they are often used by people. This study evaluated the acute effect of UVA and UVB filters - Benzophenone-3 (BZ- 3), Octyl Salicylate (OS) and Octyl Methoxycinnamate (OMC), detected in commercial sunscreens, performing the test both in a mixture as isolated – using Nitokra sp copepod and the method described in ISO14669:1999. When exposed to the water soluble fraction of the UV filters mixture, the mean of LC50-96h was 11.47 %, corresponding to 190 mg.L-1 of BZ-3, 150 mg.L-1 of OS and 230 mg. L-1 of OMC, while the isolated UV filter showed a tendency to increased lethality.The tests were performed in parallel with the reference substance DSS, and were within the acceptability limits of the LECOTOX LC50-96h = 7.76 (3.98-11.55) mg.L-1 DSS. It was concluded that the test organism and the method used were suitable for the tests with the commercial UV filters mixture and that, although the filters used are fatsoluble, there are bioavailable concentrations in the environment. The tested mixture caused deleterious effects to Nitokra sp. in concentrations lower than ANVISA (2006) allows, therefore more research is needed.

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  • IPEN-DOC 27053

    PUSCEDDU, F.; SANTOS, D.R.; MORENO, B.B.; GUIMARÃES, L.; CORTEZ, F.S.; PEREIRA, C.D.S.; CHOUERI, R.B.; SANTOS, A.R.; ROGERO, S.O. ; ROGERO, J.R. ; CESAR, A.. Marine sediment contamination in a subtropical zone (Santos Bay, Brazil): pharmaceuticals, personal care products and cocaine. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 64-64.

    Abstract: Although the continuous input of domestic sewage in coastal areas has been reported, few data are available about the presence of pharmaceuticals and personal care products (PPCPs) in coastal environments of South America. The aim of this study was to determine the environmental concentration of PPCPs and cocaine in sediments from Santos Bay (Brazil), a degraded coastal area due to urban and industrial pollution. A sediment sample, collected at five points around the Submarine Sewage Outfall of Santos, was analyzed by liquid chromatography-tandem mass spectrometry (LCMS/ MS) and 35 compounds were investigated. The presence of five pharmaceuticals (caffeine, carbamazepine, diclofenac, fluoxetine and ibuprofen), one personal care product (triclosan), and one illicit drug (cocaine) was evidenced. Considering the absence of information about the occurrence of PPCPs and illicit drugs in marine sediments of tropical and subtropical areas of South America, the data reported here subsidize the \nassessment of environmental risks of such substances in coastal zones.

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  • IPEN-DOC 27052

    CAMARGO, J.; SOUSA, E.P.; CATHARINO, M.G. ; GASPARRO, M.R.; ABESSA, D.M.; FERNANDES, I.; LINS, C.G.; VASCONCELLOS, M.B. . Lysosomal stability in oysters Crassostrea sp. from three different populations from the coast of São Paulo, Brazil. In: SETAC LATIN AMERICA BIENNIAL MEETING, 12th, September 7-10, 2017, Santos, SP. Abstract... 2017. p. 39-39.

    Abstract: Coastal zones continuously receive inputs of contaminants, which greatly affect its quality. Biological effects resulting from environmental pollution are complex and have not been properly estimated by chemical analysis and toxicity tests. A reliable form to assess the environmental quality consists of analyzing organisms exposed to constant, complex and diffuse sources of contamination. The appropriate use of biomarkers in sentinel organisms may provide an estimate of the potential risk associated with contamination. This study aims to evaluate if different levels of potential contamination affect differently the stress responses in oysters from three sites along the coast of São Paulo state. The physiological condition of oysters Crassostrea sp. from Cananéia (reference site), Santos and Bertioga was studied by analyzing the lysosomal membrane stability in haemocytes, measured using the neutral red retention time (NRRT) assay. Adult organisms were collected in spring (August, September, and October/2016) and autumn (April and May/2017). During the spring, the times of retention of the neutral red dye were similar in oysters from different sites and the reference area (p > 0.05). Interestingly, an uncommon red tide occurred along the coast of the state mainly affecting Cananéia, which may have influenced the reduction of the NRRT for oysters from this region. Such biological events (algal blooms) are more likely to occur at this time of year due to the typical climatic conditions, and may have the potential to even the adverse effects of pollution on distinct bivalve populations subject to different levels of contamination. During the autumn campaign, organisms from both contaminated sites (Santos and Bertioga) showed significant reduction in the mean NRRT relative to the reference site (p < 0.05). A previous study in the same region (Catharino et al., 2015) observed that in both seasons the oysters from Cananéia had a higher NRRT than the oysters from the other two sites. Overall, the NRRT were lower in the present study. These results may be due to the exposure of the organisms to pollutants, since lysosomes are organelles that absorb a wide variety of organic and inorganic substances. However, further investigations are required and being carried out to confirm this hypothesis.

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  • IPEN-DOC 27045

    KOSKINAS, M.F. ; YAMAZAKI, I.M. ; DIAS, M.S. . Standardization of 59Fe by 4π(PC)β-γ software coincidence system. In: INTERNATIONAL CONFERENCE ON RADIONUCLIDE METROLOGY AND ITS APPLICATIONS, 20th, June 8-11, 2015, Vienna, Austria. Abstract... 2015. p. 127-127.

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  • IPEN-DOC 27043

    SUGAHARA, TARCILA; MOMTORO, FABIANO E.; MARTINS, GISLENE V.; MASSI, MARCOS; REIS, ADRIANO G. dos ; REIS, DANIELI A.P.. SiC/Cr thin films deposited by HiPIMS on Ti-6Al-4V used as protective coating in creep tests. In: CONGRESSO BRASILEIRO DE APLICAÇÕES À VACUO NA INDÚSTRIA E NA CIÊNCIA, 38.; WORKSHOP DE TRATAMENTO E MODI CAÇÃO DE SUPERFÍCIES, 3., 21-24 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 157-158.

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  • IPEN-DOC 27041

    REIS, ADRIANO G. dos ; REIS, DANIELI A.P.; ABDALLA, ANTONIO J.; COUTO, ANTONIO A. ; BRIGUENTE, LUCIANA A.N. da S.; MARCHETTO, LUIZ R.O.; LOPEZ, JAVIER O.. Microstructural evaluation of maraging 300 steel laser treated. In: CONGRESSO BRASILEIRO DE APLICAÇÕES À VACUO NA INDÚSTRIA E NA CIÊNCIA, 38.; WORKSHOP DE TRATAMENTO E MODI CAÇÃO DE SUPERFÍCIES, 3., 21-24 de agosto, 2017, São José dos Campos, SP. Resumo expandido... 2017. p. 46-47.

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  • IPEN-DOC 27040

    CAVALCANTE, F. ; PECEQUILO, B.R.S. ; LEONARDO, L. . Activity concentrations of natural and artificial radionuclides in feline dry food. In: INTERNATIONAL CONFERENCE ON ENVIRONMENTAL RADIOACTIVITY, September 21-25, 2015, Thessaloniki, Greece. Abstract... 2015.

    Abstract: Natural radiation exposure is an inherent condition to all living species, once radionuclides from the 238U and 232Th chain can nearly be found in all places. Information on radionuclides concentration and exposure levels, from natural and anthropogenic sources are absolutely necessary to investigate the possible effects that ionizing radiation can induce. These can be very different depending on the organism considered and the exposure pathway. In recent decades, the exposure of non-human species to ionizing radiation has been specially considered and investigated (ICRP, 2014) by a vast number of scientists and organizations, once they differ widely from the exposure of human beings. Brazil holds the second largest cat and dog population in the world, consuming over 2 million tons of feed every year. The country also stands out for its production of pet food that produced 2.4 million of tons of feed in 2014, representing the world’s second largest industry. A novel study regarding the radionuclide content in different dog and cat food is being developed since 2013 and preliminary results have been presented by Cavalcante, F. and Pecequilo (2014), for selected dry dog food. The present study presents an evaluation of the radionuclide and radioactivity content of different brands of dry cat food, commonly found in local markets in the city of Sao Paulo, Brazil. Thirteen different samples were crushed into powder and kiln dried before tightly sealed in 100 mL HDPE flasks, with a plan screw cap and bubble spigot. These samples, after resting for 30 days to ensure secular equilibrium, were placed in an extended range coaxial germanium detector (Canberra XtRa GX4020 detector) for 150 ks and the acquired spectra were analyzed with the InterWinner 6.0 software (InterWinner, 2004). The natural radionuclides considered were 238U, 232Th and 40K, the anthropogenic radionuclides investigated were 60Co, 131I, 137Cs and 134Cs. The results for the considered artificial radionuclides have shown activity concentration values below the detector’s MDA (Minimum Detectable Activity), as in Table 1. The concentrations of natural radionuclides ranged from 1.12 ± 0.29 Bq/kg to 3.77 ± 0.36 Bq/kg for 226Ra; from 1.48 ± 0.40 Bq/kg to 6.27 ± 0.78 Bq/kg for 232Th and from 216.8 ± 11.2 Bq/kg to 361.7 ± 16.8 Bq/kg for 40K, as shown in Figure 1. The results suggest that the samples evaluated have no contamination of artificial radionuclides and the natural radionuclides concentration will not contribute to significant absorbed dose by their ingestion. Therefore, the authors conclude that these studied brands carry no radiological risk for the animals ingesting them.

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  • IPEN-DOC 27034

    VARCA, GUSTAVO H.C. ; BARROS, JANAINA A.G. ; BATISTA, JORGE G.S. ; SASOUNIAN, RAFAELA; SILVA, GUSTAVO T.M.; ZAMARION, VITOR M.; KATTI, KATTESH V.; LUGAO, ADEMAR B. . Protein crosslinking onto gold nanoparticles by gamma radiation. In: DUDALA, JOANNA (Ed.); CIECHANOWSKI, MAREK (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 10-13, 2017, Kraków, Poland. Abstract... Kraków, Poland: AGH University of Science and Technology - Faculty of Science and Applied Computer Science, 2017. p. 43-43.

    Abstract: The use of gold nanoparticles for diagnosis and treatment of cancer has received great attention over the last decade. Particularly, the possibility to use them for theranostics has increased the interest in the medical and scientific community. Weak technological aspects are related to the low biological affinity and non-specific toxicity. The use of albumin is of highlighted interest as albumin has been associated to inorganic particles to overcome biopharmaceutical challenges, including site-specific delivery and other biopharmaceutical advantages. The current work addresses the use of radiation and its effects over the crosslinking of bovine serum albumin onto gold nanoparticles. The idea of crosslinking the albumin onto gold surface aims to improve the stability of the protein layer onto gold nanoparticles in biological systems. Gold nanoparticles were synthesized by green technology using resveratrol and albumin capping was performed by physiosorption followed by irradiation at doses of 2.5, 5, 7.5, 10 and 15 kGy using 60Co as a radioactive source. Nanoparticle properties were assessed by dynamic light scattering, UV/Vis spectrophotometry and transmission electron microscopy. Protein crosslinking was monitored by fluorescence studies and stability of the nanoparticles was evaluated by zeta potential and titration with sodium chloride. The results evidenced the formation of a protein layer onto gold nanoparticles and revealed a protein crosslinking by means of bityrosine as a function of irradiation dose. Stability was considerably improved by the presence of the protein layer and the crosslinked protein layer.

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  • IPEN-DOC 27033

    OLIVEIRA, JUSTINE P.R. de ; OLIVEIRA, MARIA J.A. de ; SILVA, ISABELA C. da ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. . Influence of different gamma radiation doses on PVA/gelatin based scaffolds. In: DUDALA, JOANNA (Ed.); CIECHANOWSKI, MAREK (Ed.) INTERNATIONAL CONFERENCE ON DEVELOPMENTS AND APPLICATIONS OF NUCLEAR TECHNOLOGIES, September 10-13, 2017, Kraków, Poland. Abstract... Kraków, Poland: AGH University of Science and Technology - Faculty of Science and Applied Computer Science, 2017. p. 27-27.

    Abstract: The present work aimed to study the influence of different radiation doses on a polymer blend at cryogenic and room temperature by means of crosslinking formation, pore size, morphology, topography and mechanical properties. The scaffold was prepared based on two formulations, one composed by gelatin (7%, w/w) and PVA (5%, w/w), and the second by gelatin (10%, w/w) and PVA (5%, w/w). The formulations were separately solubilized in distilled water and heated up to 80 ºC under constant stirring for 1 hour. Posteriorly, both blends were disposed in circular glass moulds. Half of samples was frozen for at least 24 h and then irradiated at 15, 25 and 50 kGy. The other half was cooled at 4 ºC for at least 24 h and then irradiated using the same doses. After irradiation both sample groups were frozen and freeze dried. The scaffold was characterized in terms of structure and morphology by mechanical assays, differential scanning calorimetry, scanning electron microscopy, optical coherence tomography and infrared spectroscopy. In addition, platelet adhesion and release, and cytotoxic assays were also performed. Samples irradiated at 15 kGy presented pore size diameter of around 1.4 μm and porosity of 54%, while samples irradiated at 25 kGy, presented pore size diameter of around 1.1 μm and porosity of 49%. Optical coherence tomography showed that gelatin control samples presented more superficial degradation as irradiation dose increased, while PVA control sample presented higher integrity, indicating that this polymer is less sensitive to gamma radiation. The system presented suitable mechanical properties and the platelet adhesion and release assays showed that the scaffold presented adequate pore size range to host and release the platelets, and non-cytotoxic to platelets, featuring adequate properties to be applied as dressing for wound treatments.

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  • IPEN-DOC 27031

    MUNHOZ JUNIOR, A.H.; MIRANDA, L.F.; SILVA, L.G.A. ; OLIVEIRA, M.O. de; ANDRADES, R.C.; GOMES, G.C.. Use of gamma-alumina nanoparticles for drug delivery system for releasing acyclovir. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 154-155.

    Abstract: The sol-gel process is a method for preparing porous ceramics, vitreous and crystalline materials from molecular precursors. In this process, a lattice of oxide compounds is made through reaction of inorganic materials in aqueous solution. The sol-gel process may be used to produce nanoparticles of pseudoboehmite, which are employed in drug delivery systems, production of nanocomposites and in the synthesis of gamma-alumina [1,2,3]. The firing of pseudoboehmite produces pure gamma-alumina [4,5]. The use of nanoparticles in drug delivery systems is advantageous because it prevents repeated doses and also decreases the amount of drug intake, which not only enhance the therapeutic effect, but also reduces the risks of plasma concentration reaching toxic levels. The use of synthetic nanoparticles have attracted great interest for applications in drug delivery systems. Pure gamma-alumina obtained from pseudoboehmite is a synthetic aluminum compound with excellent adsorbent properties. In this work, gamma-alumina was obtained through pseudoboehmite firing to be used for in vitro release of acyclovir. The gamma-alumina was characterized by X-ray diffraction (XRD), Differential Thermal Analysis (DTA), Thermogravimetry Analysis (TG), Scanning Electron Microscopy (SEM) using secondary electron detector and EDS detector. The release profile was obtained by UV/Vis spectroscopy for in vitro analysis. The results indicate gamma-alumina is appropriate for release of acyclovir.

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  • IPEN-DOC 27030

    MIRANDA, LEILA F. de; GOULART, LEID J.P.; SILVA, LEONARDO G. de A. e ; DONADON, ALEXANDRE C.; YAMASAKI, FABIO Y.; MUNHOZ JUNIOR, ANTONIO H.. Characterization of polystyrene nanocomposites containing nanoparticles of pseudoboehmite obtained by sol-gel process. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 153-154.

    Abstract: Polymer nanocomposites are hybrid materials in which inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. These substances have high surface area allowing a better interaction with the polymeric matrix and consequently promote changes in the physical properties of the final composite with small additions of the same. The preparation of nanocomposites with polymer matrix allows in many cases to find a relationship between a low cost due to the use of lower amount of charge, reaching high level of performance. In this work, were obtained polystyrene nanocomposites with pseudoboehmite synthesized by the sol-gel process with different concentrations of pseudoboehmite using octadecylamine as a coupling agent. The nanocomposites were prepared by the melt intercalation technique and characterized by differential thermal analysis, thermogravimetric analysis, heat deflection temperature, Vicat softening point, mechanical and rheological tests. The results showed an increase in the thermal properties, hardness and tensile strength values and decrease in the melt index, impact resistance and tensile elongation, showing the interaction of the filler with the polymer matrix.

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  • IPEN-DOC 27029

    HEILMAN, S. ; SILVA, L.G.A. . Silver and titanium nanoparticles used as coating on polyurethane catheters. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 150-150.

    Abstract: Silver nanoparticles have been used in the medical area due to their remarkable antimicrobial properties [1]. In this sense titanium dioxide nanoparticles obtained by the sol-gel method were used as coating of catheters for subsequent impregnation of silver nanoparticles with gamma irradiation and electron beam at 25 and 50 kGy [2]. This work aimed to study the use of the silver nanoparticles and titanium dioxide as coating of polyurethane Central Venous Catheter (CVC) for antimicrobial activity. Furthermore the amounts of titanium and silver present in the coated catheters had been evaluated by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Therefore the Raman spectrometry was used to identify the polymorph of titanium oxide, rutile.

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  • IPEN-DOC 27028

    MIRANDA, F.; RODRIGUES, D.; NAKAMATO, F.Y.; FRAJUCA, C.; SANTOS, G.A.; COUTO, A.A. . Microstructure and properties of composite WC-8(Co, Ni): effect of the addition of SiC. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 99-100.

    Abstract: The WC-based cemented carbides, also called hard metals, 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 as the tungsten carbide in a binder (Co, Ni) to build the microstructure. The hardness for the cemented carbides based on nickel, because of the addition of reinforcements SiC nano-whisker increases significantly [3]. In this work, the SiC was researched as an additional component for composite WC-8(Co, Ni). Four mixtures were prepared with SiC content ranging from 0 to 3.0 wt%. These mixtures were pressed (200 MPa) and green samples with 25.2 mm of diameter and 40g were produced. Sintered were carried out in Sinter-HIP furnace (20 bar). Two sintering cycles were investigated with 1380 and 1420°C, and the sintering time considered was 60 minutes. The relative density, hardness, linear and volumetric shrinkage were determined. Microstructural evaluation was performed by optical microscopy and scanning electron microscopy (SEM-FEG). The results showed that the addition of SiC promoted higher densification and grain growth. The hardness was higher for samples with SiC, so solid solution hardening of the binder was more effective than WC grain growth.

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  • IPEN-DOC 27027

    REIS, A.G. ; REIS, D.A.P.; ABDALLA, A.J.; OTUBO, J.; COUTO, A.A. . An in situ high-temperature X-ray diffraction study of phase transformations in maraging 300 steel. In: INTERNATIONAL CONFERENCE ON DIFFUSION IN SOLIDS AND LIQUIDS, 12th, June 26-30, 2016, Split, Croatia. Abstract... DSL Conference, 2016. p. 95-95.

    Abstract: The phase transitions in the maraging 300 steel were studied using high temperature X-ray diffractometry. Maraging are ultra-high resistant steels with Ni-Co-Mo-Ti presenting a broad range of application in key areas such as nuclear and aerospace industries [1]. Prolonged high temperature exposure would lead to the formation of equilibrium austenite and ferrite phases [2]. Solution annealed maraging 300 steel was continuously heated at a 10 ºC/min rate from ambient temperature until 900 ºC and X-Ray measurements were done at 25, 400, 500, 600, 650, 700, 800 and 900 ºC. Dilatometric curve at the same heating rate and temperature range were performed and the results were compared with high temperature X-Ray diffraction. The martensite to austenite transformation and vice-versa could be detected by both techniques, although the precipitation could be detected only by dilatometry, associated to low volume of precipitates to be detected by X-Ray diffraction. The effect of austenite reversion at 600ºC was also studied after at 1, 2, 3 and 4 hour of exposure, showing that the amount of reverted austenite is proportional of time exposure at high temperature.

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  • IPEN-DOC 27023

    LIMA, CASSIO A. ; CORREA, LUCIANA; ZEZELL, DENISE M. . Infrared spectroscopy determining the biochemical changes in premalignant skin lesions submitted to photodynamic therapy. In: WORKSHOP FTIR SPECTROSCOPY IN MICROBIOLOGICAL AND MEDICAL DIAGNOSTICS, 11th, October 19-20, 2017, Berlin, Germany. Abstract... 2017.

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  • IPEN-DOC 27021

    RODRIGUES, PATRICIA F. ; WHITEMAN, DAVID; VANABLE, DIMITRIUS; DEMOZ, BELAY; WALKER, MONIQUE; LANDULFO, EDUARDO . Comparison of the hygroscopic behavior of aerosols obtained by Raman LIDAR and nephelometry: the NASA Discover-AQ experience. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: The hygroscopic behavior of aerosols is of great interest in the recent decades because of the importance in computing the radiative forcing of aerosols in the energy balance of the planet. The last report of the IPCC in 2013 shows that the uncertainty associated to the interactions between aerosols and clouds is high, and more research in this area is needed in order to give more information about the indirect effect of aerosols. The LIDAR (Light Detections and Ranging) is a technique that can be used to study the hygroscopic growth of aerosols under varying relative humidity conditions, and the main advantage of the technique is the possibility of studying the hygroscopicity next to the saturation in an unperturbed atmosphere. During the NASA Discover-AQ in 2011, a Raman LIDAR operated at the Howard University in Beltsville, United States, at the same time a nephelometer inside an airplane was sampling the same aerosol population. Then, the hygroscopic growth factor of the aerosols was computed using both instruments, and the results are now being compared. In this work, the result obtained by the LIDAR will be shown and compared to the nephelometer results obtained by Ziemba et al (2013) for 05 July 2011. The different methodologies adopted are explained and discussed. The good agreement between both instruments shows LIDAR is a promising technique in this field of study.

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  • IPEN-DOC 27020

    GUERRERO-RASCADO, JUAN L.; LOPES, FABIO J.S. ; ALADOS-ARBOLEDAS, LUCAS; HOELZEMANN, JUDITH J.; FERNANDEZ, JOSE H.; LEME, NEUSA P.; LANDULFO, EDUARDO . On the meteorological scenarios and main air mass paths at the LALINET Natal station (Northeastern Brazil). In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: To continue the effort in understanding the role of aerosol particles on continental scale, the Latin American Lidar Network (LALINET) [Guerrero-Rascado et al., 2014] will spread its activities to the North-eastern part of South America in the near future. A new LALINET station will be deployed at Natal (Rio Grande do Norte, Brazil, 5.84º S, 35.20º W) with the aim of characterizing the transcontinental transport of aerosol particles from Africa to South America, mainly Saharan dust and biomass burning, before their potential contamination with local particles. This study is conceived as a preliminary characterization on the atmosphere over Natal based on meteorological features including air mass clustering. On one hand, this work will allow to identify periods with the largest frequency of Saharan dust outbreaks and biomass burning episodes over Natal. On the other hand, it will provide a statistically detailed characterization of meteorological conditions in this region. To this aim, GDAS information (Global Data Assimilation System) will be the inputs in our analyses and HYSPLIT model (Hybrid Single Particle Lagrangian Integrated Trajectory model) (version 4.9) will be used to generate daily backward trajectories at six standardized height levels.

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  • IPEN-DOC 27019

    MOREIRA, GREGORI de A. . Intercomparison of wind data observed with Wind Doppler LIDAR and SODAR at Ressacada, Florianópolis-Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: Nowadays, remote sensing equipment has long been used for various studies related to atmosphere. When wind speed issues are discussed, the Wind Doppler LIDAR and SODAR deserve to be highlighted due to high vertical resolution of both and the high data acquisition rate. This equipment has been very applied in academic studies for environmental issues and also in the industry as wind power projects and airport security. Though each has its limitation, they enable different types of studies, which range from the observation of the vertical wind profile until the detection of turbulent phenomena. The main objective of this work is to do an intecomparison between these two technologies. For this study one measurement campaign was conducted in Florianópolis (Santa Catarina State - Brazi) and a case study will be presented, where were employed a Wind Doppler LIDAR WL70 Leosphere operating with wavelength of 1.5 m and maximum range of 1,500 meters and a SODAR MFAS SCINTEC with maximum range of 800 meters. It will be held: a statistical analysis in relation to the wind velocity and wind direction values, analysis of the turbulence and detection of PBL (planetary boundary layer) height. Both devices will be validated by atmospheric sounding data from the airport near the study area. From the results of this work are expected to find consistent values of correlation between the two devices and demonstrate its wide applicability, although each one have your different limitations, in the various areas of knowledge.

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  • IPEN-DOC 27018

    LANDULFO, EDUARDO ; LOPES, FABIO da S. ; QUEL, EDUARDO; RISTORI, PABLO; BASTIDAS, ALVARO; NISPERUZA, DANIEL; BARBOSA, HENRIQUE; BARJA, BORIS; GOUVEIA, DIEGO A.; FORNO, RICARDO; MONTILLA, ELENA. LALINET a.k.a. Activities. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: The LALINET network activities will be given focusing on the lidar station characterization in the network, the efforts given to standardize the algorithms as weel the main scietific drives for data collection.

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  • IPEN-DOC 27017

    LOPES, FABIO J.S. ; ARRUDA, GREGORI M. de ; ARAUJO, FELIPE V. ; LANDULFO, EDUARDO . Synergy between multichannel Raman Lidar system and spaceborne remote sensing platforms applied to study aerosol optical properties at Metropolitan Area of São Paulo - Brazil. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: In the last decades, several remote sensing platforms, i.e., spaceborne, aircraft and ground-based measurement systems have been developed or improved to conduct studies of aerosol and cloud optical properties on local and global scales, as well as to provide the scientific basis for understanding the Earth climate system. The combination measurements between spaceborne sensors and ground-based instruments can helps to provide a better understanding about the impact of aerosols on air quality and in the climate changes inside large cities. The Metropolitan Area of São Paulo (MASP), one of the largest megacities in the world, frequently suffers with problems related to the air quality. Concerned with the pollution scenario of MASP, several measurement campaigns were conducted since 2012, specially, during the South hemisphere winter, period when the low temperatures and the low level of precipitation contribute to the poor dispersion of aerosols. A multichannel Raman Lidar system and air quality monitoring stations from University of São Paulo and Environment Agency of São Paulo State (CETESB) were employed in order to monitor the increasing of aerosol load in the atmosphere. Satellite data from CALIPSO and AQUA were applied to draws the pollution scenario and the most frequent aerosol type at MASP. This study intend to present how the synergy between ground-based monitoring and satellite data can helps to improve the studies the effects of particulate matter concentration in the air quality of MASP and the influence of aerosol from biomass burning advected from large range distance of South American continent.

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  • IPEN-DOC 27016

    BARBOSA, HENRIQUE de M.J.; BARJA, BORIS; GOUVEIA, DIEGO A.; LANDULFO, EDUARDO ; ALMEIDA, PAULO ; HOLANDA, BRUNA A.; PAULIQUEVIS, THEOTONIO; ARTAXO, PAULO; MARTIN, SCOT. Disentangling the Manaus pollution plume from the biomass burning plume during the second GoAmazon 2014/5 Intensive Operating Period (IOP2). In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: The Green Ocean Amazon experiment (GoAmazon2014/5) seeks to understand how aerosol and cloud life cycles are influenced by pollutant outflow from a large industrial city in the tropical rain forest, particularly the susceptibility to cloud-aerosol-precipitation interactions and the feedbacks among biosphere and atmosphere functioning and human activities. For this purpose, six research sites were setup at different distances upwind and downwind from Manaus, in the central Amazon forest, and three of these have vertical profiling capabilities. A micropulsed lidar (MPLnet) from DOE/ARM is being operated at T3 site (3.21°S 60.59°W), 60 km downwind to the west of Manaus. A portable Raymetrics aerosol raman lidar from IPEN/SP was operated T2 site (3.21 ºS 60.60 ºW, 5 km downwind) during the second Intensive Operating Period (IOP2), and measures directly the emissions from Manaus. The third system is the UV Raman lidar from the University of Sao Paulo, continuously operated since 2011 at T0e (2.89 ºS 59.97 ºW), an upwind site 10 km to the east. T0e serves as a reference station, as the air masses there are not influenced by the local urban emissions. Using these three lidar systems and the AERONET stations at T3 and T0e, the scattering and absorption properties of the Manaus and biomass burning plumes were investigated. The measurements were conducted during the biomass-burning season, from August 15 to October 15 2014. Scattering aerosol optical thickness varied from 0.1 to 1.5, with a regression coefficient of 0.980.02, showing similar scattering properties at T0e vis-à-vis T3 and thus little influence of the Manaus plume. For the absorption AOD, however, values ranged from 0.05 to 0.8 and the regression coefficient was 2.2(2), indicating a much more absorbing aerosol at T3. A similar result was observed in the vertical. The aerosol backscatter profiles from T2 and T0e were remarkably similar, and even small-scale vertical structures of about ~100m inside the biomass burning plume were not destroyed as the air mass travels 36 km over the city and the river. The night-time aerosol extinction profiles, however, showed substantially more absorption at T2 then at T0e although not enough to justify the different absorption AOD. Possible reasons will be explored and discussed.

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  • IPEN-DOC 27015

    LANDULFO, EDUARDO ; LOPES, FABIO J.S. ; MOREIRA, GREGORI A. ; GUERRERO-RASCADO, JUAN L.; ALADOS-ARBOLEDAS, LUCAS; HOELZEMANN, JUDITH J.; FERNANDEZ, JOSE H.; LEME, NEUSA P.. Observation and characterization of the transcontinental aerosol transportation from Africa to South America continent: introducing a new Lidar system to LALINET. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: Saharan mineral dust can affect the environment and climatic processes from the Western Africa, Europe and the Eastern region of Americas due the large carrying processes of dust aerosol. This type of aerosol can interact with the incoming energy from the Sun and alter radiation budget of the Earth-atmosphere system. Dust particles can also change the cloud lifetime and albedo; they can induce precipitation and indirectly influence the convective clouds height. Several studies have been conducted to understanding the physical and optical properties of dust particles, using systems onboard satellites, airborne or ground-based instruments. However, most of the studies were focused on African, European or North America regions. In order to fill the scientific knowledge gap in the South America region it has been developed a new lidar system to study the transcontinental transportation of dust aerosols from Sahara region to South America. The project has as objectives monitoring the dust aerosols transportation seasonality, their vertical distributions in the atmosphere, their physical and optical properties and their influences on the radiative budget. For this task, a four-channel ground based lidar for aerosol profiling, including polarization, is being deployed at the city of Natal, in the North-Northeast region of Brazil. In this study, we present a review of the project current instrumental status, instrument technical specification, the potential results to be obtained and the entire performance test to be done in order to introduce the new lidar system into Latin American Network LALINET according to procedures developed by Guerrero-Rascado et al 2014.

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  • IPEN-DOC 27014

    CORDOBA-JABONERO, CARMEN; LOPES, FABIO J.S. ; LANDULFO, EDUARDO ; CUEVAS, EMILIO; OCHOA, HECTOR; GIL-OJEDA, MANUEL. Subtropical and polar Cirrus clouds characterized by ground-based lidars and CALIPSO/CALIOP observations. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: Cirrus clouds are product of weather processes, and then their occurrence and macrophysical/optical properties can vary significantly over different regions of the world. Since Cirrus clouds usually are located from 7 km height up to tropopause altitudes, active remote sensing techniques, mainly lidar systems, are usually used for detection of Cirrus clouds from ground-based and space observations. Lidars can provide height-resolved measurements with a relatively good both vertical and temporal resolutions, making them the most suitable instrumentation for high-cloud observations. The aim of this work is to show the potential of lidar observations on Cirrus clouds detection in combination with a recently proposed methodology to retrieve the Cirrus clouds macrophysical and optical features. In this sense, a few case studies of cirrus clouds observed at both subtropical and polar latitudes are examined and compared to CALIPSO/CALIOP observations. Lidar measurements are carried out in three stations: Sao Paulo (Brazil, 23.6°S/46.8°W) and Sta. Cruz de Tenerife (Spain, 28.5°N/16.3°W), being both subtropical sites, and the Belgrano II base (Argentina, 78ºS/35ºW) in the Antarctic continent. Local radiosounding profiles are also used for cirrus-temperature correlation analysis. Optical (COD-cloud optical depth and LR-Lidar Ratio) and macrophysical (top/base heights and thickness) properties of both the subtropical and polar cirrus clouds are reported. This study is focused on the classification of the daily cloud features into three Cirrus COD-related categories: svCi-subvisual (COD < 0.03), stCi-semitransparent (COD: 0.03 - 0.3), and opCi-opaque (COD > 0.3) clouds. In general, subtropical Cirrus clouds present lower LR values and are found at higher altitudes than those detected at polar latitudes. Additionally, a higher svCi presence is observed over the polar station along the day, since svCi clouds are formed at lower temperatures. A good correlation agreement is also achieved between groundbased lidars and space-borne CALIOP measurements.

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  • IPEN-DOC 27013

    GONZALEZ, BORIS B.; BARBOSA, HENRIQUE; GOUVEIA, DIEGO A.; LANDULFO, EDUARDO ; ALMEIDA, PAULO . Characteristics of cirrus clouds in the Central Amazon region during the Intensive Observational Period in the dry season 2014 as part of the GOAMAZON experiment. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: Using three lidar systems around the city of Manaus, the behavior of the cirrus clouds in the region was investigated. The measurements were conducted during the second GoAmazon 2014/5 Intensive Operating Period (IOP2), from August 15 to October 15, in the dry season of 2014. The three systems were operated continuously at the sites T3, downwind and 60 km to the west of Manaus; T2 (3.21 ºS 60.60 ºW), also downwind of Manaus but just across the Negro river to the west; and T0e (2.89 ºS 59.97 ºW), an upwind site east of Manaus located in campus of Embrapa. These different sites were selected for GoAmazon 2014/5 to measure the effects on aerosols and clouds of different levels anthropogenic pollution, in an otherwise pristine tropical rainforest environment. From the analysis of individual 5-min backscatter profiles, we investigate the statistical distribution of cirrus clouds base and top altitude characteristics; and also the cloud optical depth for the three sites. Mean characteristics for the cirrus clouds measured in the three sites are discussed and the relations between these results are investigated. The cirrus clouds are frequent cloud in the three sites during the dry season. Comparisons with cloud optical depth from sun-photometer in T0e and T3 sites and base height from ceilometer in T3 site were conducted.

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  • IPEN-DOC 27012

    GUERRERO-RASCADO, J.L. ; COSTA, R.F. da ; BEDOYA, A.E.; GUARDANI, R.; ALADOS-ARBOLEDAS, L.; BASTIDAS, A.E.; LANDULFO, E. . Recent advances in the Cubatão scanning lidar to monitor industrial flares. In: WORKSHOP ON LIDAR MEASUREMENTS IN LATIN AMERICA, 8th, April 6-10, 2015, Cayo Coco, Cuba. Abstract... 2015.

    Abstract: This study present the recent advances made on a multiwavelength elastic scanning lidar placed at the industrial area of Cubatão in the State of São Paulo (Brazil). Special attention has been paid to the characterization of the instrumental performance of this lidar system, in particular regarding to its electronic subsystem. To this aim, the quality assurance tests, regularly applied in well-established lidar networks such as LALINET and EARLINET, were applied to the Cubatão scanning lidar in order to improve the knowledge of its performing itself and to design protocols for correcting lidar signal for undesirable instrumental effects. In particular, the trigger delay was assessed by means of zero-bin and bin-shift tests for analog and photo-counting signals, respectively. Dark current test is also performed to detect potential range-dependency that could affect lidar products. The application of the results derived from these tests together with the state-of-the-art methodologies to characterize the particle optical and microphysical properties inside industrial flares demonstrate the potential of this lidar for the study and measurement of industrial emissions.

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  • IPEN-DOC 27008

    MILANI, CAIO J.; BEVILACQUA, JOYCE da S.; RODRIGUES JUNIOR, ORLANDO . Simulation of the difusion of ferric ions in fricke-gel dosimeters with a variable difusion coefficient. In: WORKSHOP ON MATHEMATICAL METHODS AND MODELING OF BIOPHYSICAL PHENOMENA, March 1-7, 2015, Cabo Frio, RJ. Abstract... Rio de Janeiro, RJ: Instituto de Matemática Pura e Aplicada, 2015.

    Abstract: Dosimetry in three dimensions allows the confirmation and a better understand-ing of a treatment in Radiotherapy. Fricke-Gel dosimeters are tissue equivalentand can be molded in different geometries and volumes. After the irradiation,the assessment of the irradiated volumes can be performed with magnetical res-onance imaging (MRI) or optical-CT. On both cases, the quality of the imagescan be compromised by the mobility of the ferric ions (F e3+), formed during thethe interaction of the radiation with the matter, increasing the uncertainty inthe determination of the isodoses in the volume. In this work, the phenomenonof the diffusion of the ferric ions formed by an irradiated region is simulated ina three-dimensional domain considering a variable diffusion coefficient. This dy-namic is modeled by a partial differential equation and solved numerically by anADI algorithm. Graphical visualizations of the phenomenon are presented forbetter understanding of the process.

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  • IPEN-DOC 27007

    MILANI, CAIO J.; BEVILACQUA, JOYCE da S.; RODRIGUES JUNIOR, ORLANDO . Numerical simulation of the difusion of ferric ions in fricke-gel dosimeters. In: CHILEAN WORKSHOP ON NUMERICAL ANALYSIS OF PARTIAL DIFFERENTIAL EQUATIONS, 50th, January 11-15, 2016, Concepción, Chile. Abstract... Concepción, Chile: Centro de Investigación en Ingeniería Matemática - Universidad de Concepción, 2016.

    Abstract: Radiation Dosimetry is a field concerned in measuring absorbed doses of radia- tion using different techniques. The chemical dosimetry using Fricke-Gel dosimeters allows the confirmation and a better understanding of radiotherapy treatments. This technique involves the assessment of volumes composed by irradiated ferrous sulphate solutions and the dose es- timatives can be evaluated using images from optica-CT or magnetic resonance. In both cases, the time elapsed between the irradiation and the evaluation of doses is an important factor, because the ferric ions formed after the irradiation begin to move along the gel matrix causing imperfections in the obtained estimatives. In this work, the dynamics involving the ferric ions, modelled by Fick's Second Law, is investigated and solved numerically. A suitable numerical method was chosen regarding the theoretical aspects such as convergence, consistency, stabil- ity and computational efficiency to simulate the diffusion of the ferric ions in bidimensional and tridimensional enviroments under several hypothesis such as multiply connected domains and non-constant diffusion coefficients. The approximated solutions were obtained with a pre- fixed precision and graphical respresentations of the phenomenum are presented for a better visualization of the problem.

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  • IPEN-DOC 26993

    HELENO, S.A.; VILLAVICENCIO, A.L.C.H. ; BARROS, L.; FERREIRA, I.C.F.R.. A influência da radiação gama na composição nutricional de flores comestíveis de Bauhinia variegata L. provenientes do Brasil. In: BENTO, ALBINO A. (Ed.) CONGRESSO NACIONAL DAS ESCOLAS SUPERIORES AGRÁRIAS, 1., 2-3 de dezembro, 2015, Bragança, Portugal. Resumo... Bragança, Portugal: Instituto Politécnico de Bragança, Escola Superior Agrária, 2015. p. 249-249.

    Abstract: Desde há muitos anos que a utilização de flores comestíveis na culinária se tornou uma prática comum, uma vez que conferem uma melhor qualidade sensorial e nutricional aos alimentos, para além do aspeto visual atrativo [1,2]. Bauhinia variegata L. é uma árvore muito comum no Brasil, sendo as suas flores grandes e de coloração lilás na variedade mais comum. Estas flores são vulgarmente conhecidas como “pata de vaca”, sendo comestíveis e muito utilizadas em saladas e na decoração de vários pratos nas cozinhas Gourmet. No presente estudo, as flores foram submetidas a radiação por feixe de eletrões em diferentes doses (0.5 e 0.8 KGy) para efeitos de descontaminação, e seguidamente analisadas em termos de parâmetros nutricionais nomeadamente, composição centesimal (humidade, proteínas, gordura, hidratos de carbono e cinzas), perfil em açúcares livres (determinados por HPLC-RI) e em ácidos gordos (analisados por GC-FID). As amostras não irradiadas (controlo) e irradiadas revelaram um perfil nutricional muito similar, sendo que os hidratos de carbono foram os nutrientes mais abundantes, seguidos das proteínas, cinzas e gorduras. Relativamente aos açúcares, as amostram mostraram também um perfil semelhante, tendo sido identificados: a frutose em maior quantidade, seguida da glucose e da sacarose. Os ácidos gordos: palmítico (C16:0), esteárico (C18:0), oleico (C18:1n9), linoleico (C18:2n6) e α-linolénico (C18:3n3) foram os mais abundantes nas amostras em estudo, tendo sido identificados mais 16 ácidos menos abundantes. Os ácidos polinsaturados (PUFA) foram maioritários, seguidos dos saturados (SFA) e monoinsaturados (MUFA). Também neste caso as amostras revelaram uma composição muito idêntica. Em suma, a técnica de irradiação pode ser utilizada como forma de descontaminação e preservação de flores comestíveis uma vez que as doses aplicadas não alteraram significativamente os parâmetros nutricionais das amostras em estudo.

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  • IPEN-DOC 26990

    HELENO, SANDRINA A.; VILLAVICENCIO, ANNA L.C.H. ; BARROS, LILLIAN; FERREIRA, ISABEL C.F.R.. Efeitos da radiação por feixe de eletrões no valor nutricional de Bauhinia variegata var cândida: flores comestíveis provenientes do Brasil. In: SIMPÓSIO NACIONAL PROMOÇÃO DE UMA ALIMENTAÇÃO SAUDÁVEL E SEGURA, 2., 26 de novembro, 2015, Lisboa, Portugal. Abstract... Lisboa, Portugal: Instituto Nacional de Saúde Doutor Ricardo Jorge, 2015. p. 64-64.

    Abstract: As flores comestíveis têm sido muito utilizadas nas artes culinárias, sendo uma tradição em todo o munto desde há muitos anos. São utilizadas várias formas, cores e sabores de flores comestfveis, com o objetivo de melhorar a qualidade sensória! e nutricional dos alimentos [1,2]. As flores de Bauhinia variegata L. são grandes e apresentam coloração rosa a lilás na variedade mais comum, ocorrendo ainda uma variedade de flores brancas, denominada B. variegata var Cândida. Estas flores são vulgarmente conhecidas como "pata de vaca branca", sendo comestíveis e muito utilizadas em saladas. No presente estudo, as flores foram submetidas a radiação por feixe de eletrões em diferentes doses (0.5 e 0.8 KGy) como forma de descontaminação, e analisadas em termos de parâmetros nutricionais nomeadamente, composição centesimal (humidade, proteínas, gordura, hidratos de carbono e cinzas) e perfil em açúcares livres (determinados por HPLC-RI) e em ácidos gordos (analisados por GC-FID). As amostras controlo (não irradiadas) e irradiadas apresentaram um perfil muito semelhante; os hidratos de carbono foram os nutrientes mais abundantes nas amostras, seguidos das proteínas, gorduras e cinzas. Os perfis em açúcares foram também similares, estando presentes a frutose em maior quantidade, seguida da gtucose e da sacarose. Os ácidos capróico (C6:0), caprílico (C8:0), cáprico (C10:0), láurico (C12:0), mirístico (C14:0), palmítico (C16:0), esteárico (C18:0) e oleico (C18:1n9) foram os ácidos gordos mais abundantes nas amostras em estudo. Os ácidos gordos saturados (SFA) foram majoritários, seguidos dos mono (MUFA) e potinsaturados (PUFA). No entanto, com maior dose de radiação a percentagem de SFA e MUFA diminui ligeiramente (principalmente ácidos esteárico e oleico, respetivamente), aumentando a percentagem de PUFA (principalmente pelo aumento dos ácidos linoleico e a-linolénico). Em suma, as doses de irradiação aplicadas não alteraram significativamente o valor nutricional das amostras em estudo, podendo ser considerada como técnica de descontaminação e preservação de flores comestíveis.

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  • IPEN-DOC 26985

    COUTO, CAMILA P. ; COSTA, ISOLDA ; COLOSIO, MARCO; GOMES, MAURILIO ; ROSSI, JESUALDO ; BOLSANELLO, MARILIA . Influence of heat treatment on corrosion resistance of press hardened steel coated with AlSi and ZnNi. In: EUROPEAN CORROSION CONGRESS; INTERNATIONAL CORROSION CONGRESS, 20th; PROCESS SAFETY CONGRESS, September 3-7, 2017, Prague, Czech Republic. Abstract... Frankfurt, Germany: European Federation of Corrosion, 2017.

    Abstract: The ultrahigh strength boron manganese steels, also known as PHS (press hardened steels), are strategic materials for the automotive industry, satisfying safety needs and fuel reduction requirements by means of the lightweight design concept, a current trend for new vehicles. It is possible by the hot stamping process which consists in heating a steel blank to the austenitization temperature, transferring it to press tooling, forming and quenching to fully martensitic transformation. At the end of process, the steel achieves tensile strength up to 1,500 MPa. The transference step from furnace to press is a critical stage because it might promote deleterious steel oxidation. The use of metallic coatings avoids this outcome. AlSi coatings have been the most applied on PHS. Alternative coatings such as electroplated ZnNi are under investigation to evaluate their potential for replacement of AlSi coatings, besides to keep up with the high projected world demand. Zinc based coatings are advantageous comparatively to AlSi ones because they provide cathodic protection to steel substrates. In this study the influence of hot stamping heat treatment on corrosion resistance of 25MnB5 steel coated by AlSi and electroplated ZnNi has been investigated. The tests include open circuit potential measurement, electrochemical impedance spectroscopy and anodic polarization curves. The samples have been tested as received and after the heat treatment which consists in heating the sample at 900°C by 10 minutes and then, fast cooling in water. It is expect that the heat treatment changes the corrosion resistance due to the intermetallics formation at the coating layer as a consequence of diffusion.

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  • IPEN-DOC 26983

    SILVA, CAMILA R. ; RIBEIRO, MARTHA S. . Efeitos da terapia com laser em baixa intensidade em melanoma murino: estudo in vivo. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 22., 6-9 de setembro, 2017, Ribeirão Preto, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2017.

    Abstract: Introdução: A terapia com laser em baixa intensidade (TLBI) vem sendo utilizada em uma variedade de condições patológicas e tem ganhado destaque nas áreas da Saúde por ser uma alternativa terapêutica não invasiva. Entretanto, o seu uso em pacientes oncológicos ainda é controverso, já que a literatura mostra resultados conflitantes da TLBI em células tumorais. Assim, nosso objetivo neste trabalho foi investigar os efeitos da TLBI na progressão de melanoma induzido em camundongos. Métodos: Células de melanoma da linhagem B16F10 foram cultivadas em meio RPMI 1640 com 10 % de soro fetal bovino e 1 % de solução antibiótico-antimicótica e incubadas em estufa a 37 ºC com 5% de CO2. Após atingirem a confluência, as células foram contadas em câmera de Neubauer, e separadas na concentração de 1.106 células/mL. Todos os procedimentos foram aprovados pelo Comitê de Ética no Uso de Animais do IPEN-SP. Camundongos machos C57BL/6 (n=8) com aproximadamente 6 semanas de idade e massa corporal de 20 g foram inoculados na região dorsal com 1.106 células/mL de melanoma murino. Após 15 dias, quando os animais apresentaram volume tumoral de 1 cm3, eles foram separados em dois grupos: Controle (n= 4) e Laser (n=4). O grupo Laser foi exposto à TLBI de forma pontual sobre o tumor com um laser de emissão vermelha (λ= 660 nm), potência de 40 mW, energia de 6 J e fluência de 150 J/cm² por três dias consecutivos. O grupo controle foi manipulado da mesma forma, mas não recebeu irradiação. A mensuração do volume tumoral foi realizada através de um paquímetro e acompanhada durante 7 dias, utilizando a fórmula: V= 0,5.C.L2 (1) Onde: V é o volume em cm³, C o comprimento e L a largura em cm do tumor. Os dados foram analisados utilizando ANOVA-TwoWay com medidas repetidas seguido do teste de Tukey. A análise de sobrevida foi realizada através do teste de Kaplan-Meier. Resultados e Discussão: A figura 1 apresenta a evolução do volume tumoral para os dois grupos. Durante os dois primeiros dias, o volume tumoral de ambos os grupos permaneceu similar e inferior a 2 cm³. A partir do terceiro dia, os grupos mostraram o mesmo comportamento exponencial de crescimento. Entretanto, após 7 dias, o grupo controle tinha um volume médio de 11,64 ± 0,83 cm³, enquanto que o grupo laser mostrou uma progressão mais lenta e no dia 7 apresentava um volume tumoral aproximadamente 62 % menor em relação ao grupo controle. As curvas de sobrevida foram significativamente diferentes já que 13 dias pós-tratamento, todos os animais do grupo controle foram a óbito. Conclusões: Dentro dos parâmetros utilizados neste estudo, a TLBI foi capaz de inibir a progressão de melanoma em camundongos e aumentar a sobrevida dos animais. O volume do tumor é inversamente proporcional à sobrevida. Estes resultados são promissores para propor a TLBI como alternativa terapêutica em pacientes oncológicos, porém mais estudos são necessários para estabelecer seu uso seguro na prática clínica.

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  • IPEN-DOC 26981

    DONATO JUNIOR, JOSE; FURIGO, ISADORA C.; OREFICE, GABRIEL; RAMOS-LOBO, ANGELA M.; SOARES, CARLOS R.J. ; LIST, EDWARD O.; KOPCHICK, JOHN J.. GH controls glycemia and metabolic adaptations to starvation via neurons that express the leptin receptor. In: ENDOCRINE SOCIETY ANNUAL MEETING AND EXPO, 99th, April 1-4, 2017, Orlando, FL, USA. Abstract... Washington, DC, USA: Endocrine Society, 2017.

    Abstract: Growth hormone (GH) responsive neurons are extensively distributed in many hypothalamic nuclei that also have leptin receptor (LepR)-expressing cells (1). However, whether GH affects metabolic functions regulated by leptin remains unknown. In the present study, we initially performed a co-localization study and confirmed that a large percentage of LepR-expressing neurons are directly responsive to peripherally injected GH in different brain nuclei. Then, we generated mice lacking GH receptor (GHR) specifically in LepR-expressing cells (LepR GHR KO mice). Although LepR GHR KO mice exhibited a similar body weight, food intake, energy expenditure, glucose tolerance and leptin sensitivity compared to control mice, we observed a lower adiposity in mutant mice. LepR GHR KO mice also showed a lower capacity to recover from insulin-induced hypoglycemia and a blunted counterregulatory response evoked by 2-deoxyglucose (2DG) administration. Co-infusion of 2DG with sympathetic blockers, but not parasympathetic blockers, was able to abolish the differences observed between groups. Remarkably, while control mice adapted to a 60% food deprivation period by progressively saving energy, LepR GHR KO mice exhibited a blunted metabolic adaptation to starvation, which led to hypoglycemia and an increased lethality rate, energy expenditure and weight loss, compared to control animals. In order to identify the specific neuronal populations responsible for the observed responses, we generated mice lacking GHR in steroidogenic factor-1 (SF1) cells, which comprises the ventromedial nucleus of the hypothalamus (VMH). SF1 GHR KO mice exhibited a similar metabolic phenotype in the basal condition, compared to littermate controls. On the other hand, SF1 GHR KO mice also showed a lower capacity to recover from insulin-induced hypoglycemia and a blunted counterregulatory response evoked by 2DG. However, metabolic adaptations to starvation were not affected by SF1-specific GHR deletion, which suggests that VMH does not mediate these latter changes. In summary, GHR expression in the brain is required to properly regulate glycemia and energy balance, especially during situations in which GH is highly secreted (e.g., hypoglycemia and food restriction). In addition, our findings revealed a previously unrecognized role of GH to coordinate, together with leptin, the metabolic adaptations to starvation in order to ensure survival, via the same neurocircuitry.

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  • IPEN-DOC 26980

    GALANTE, RAQUEL; REDIGUIERI, CAROLINA F.; KIKUCHI, IRENE S.; VASQUEZ, PABLO ; COLAÇO, ROGERIO; SERRO, ANA P.; PINTO, TEREZINHA de J.A.. Sterilization of chitosan nanogels: the protective role of sugars. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 1720-1720.

    Abstract: A nanosystem designed for biomedical applications (e.g. injectables, ophthalmic solutions) cannot be toxic or irritating and must be sterile [1]. Therefore, sterilization is a critical but needed step, during which adverse effects can occur. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns nanogels [1]. This work aims to evaluate the effect and effectiveness of conventional terminal sterilization methods (steam heat and gamma irradiation) on chitosan hydrogel nanoparticles. Chitosan-tripolyphosphate based hydrogel nanoparticles (CS/TPP), with broad spectrum of possible applications were produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol). Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. The obtained results allowed concluding that steam heat is not a suitable method for sterilizing CS/TPP nanogel as it leads to severe degradation of the samples, with the appearance of multiple particle populations of different sizes, and large aggregates and sediments. Gamma rays exposure gave rise to immediate formation of visible sediments. However, upon the addition of protective sugars (glucose and mannitol 5%) a significant increase of the nanogel resistance to radiation was observed. This protective effect could be related with the formation of an antioxidant complex.

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  • IPEN-DOC 26979

    SOUZA, GRACIANO B. de; MULLER, DALIANA; MELLO-CASTANHO, SONIA R.H. ; FALK, GILBERTO; HOTZA, DACHAMIR; RAMBO, CARLOS R.. High surface niobium oxide ambigel for simulated nuclear waste immobilization. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 1773-1773.

    Abstract: Niobium is predominantly found in Brazil, and it is, therefore, of great interest to find new technological applications for Nb and its compounds. It has been demonstrated that porous niobium oxide glasses can be used to trap nuclear waste [1]. Glass frits require high energy processes and high sintering temperature for their production. Ambigels on the other hand can be produced under ambient conditions (~25 °C, 1 atm.) and due to their high specific area they require much lower sintering temperatures, two characteristics that attract their use as hosts for nuclear waste immobilization [2]. In this work, we produced niobium oxide ambigels intended as host matrix for simulated multicomponent liquid nuclear waste. We synthetized ambigels using niobium pentachloride (NbCl5) as precursor, ethanol as solvent and nitric acid as catalyst. Following rapid gelation the gels were left to age in ethanol, passing to hexane through sequential solvent exchange until 100% hexane were reached. In the last step, the gels were dried under ambient conditions for 48 hours. We have produced ambigels with high specific surface area (> 110 m²/g) and amorphous niobium oxide phase. The ambigels were impregnated with saline solutions that simulate a multicomponent nuclear waste. The weight gain after thermal treatment was determined and used as indicator for the amount immobilized. Nb2O5-based ambigels can be used as a mesoporous host matrix for nuclear waste immobilization.

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  • IPEN-DOC 26978

    GALEGO, EGUIBERTO ; SERNA, MARILENE M. ; TATEI, TATIANE Y. ; LIMA, BRUNA R. ; FARIA, RUBENS N. . Green synthesis of ZnO nanostructured electrode for supercapacitor. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 1348-1349.

    Abstract: The electrical double layer capacitor (EDLC), has been extensively investigated for its many applications in electric and electronic devices, due to high power density and long-life cycle. Zinc oxide (ZnO) is a promising candidate for the electrochemical supercapacitor electrode. ZnO is well known to be an active battery electrode material with a high energy density of about 650 Ag-1 [1], but it has the disadvantage of dendrites formation during consecutive cycling, which decreases life cycle. In this paper, we report a relatively straightforward, environmental friendly and low-cost method for preparing ZnO electrodes that consists in two steps. Starting with a ZnO seed layer onto a steel substrate employing the successive ionic layer adsorption and reaction (SILAR) method [2]. Subsequently, a chemical deposition bath was used for the nanostructured ZnO growth. A low temperature SILAR method was used in this study, replacing high temperature and vacuum methods, such as chemical vapor deposition or sputtering, to create an interface region between the conductive steel current collector and the nanostructured ZnO electrode. Scanning electronic microscopy has been employed in the characterization of the two-step produced nanostructured ZnO electrodes. The electrochemical performance of the nanocomposite electrodes has been investigated using cyclic voltammetry (10 to 50) mVs-1 and charge-discharge curves (1 to 20) mAcm-2 in aqueous KOH electrolyte at several concentrations. Cyclic voltammetry exhibited a broad redox peak indicative of typical reversible redox reaction of ZnO with the K+, responsible for the faradaic reactions in the supercapacitor. The enhanced electrochemical performance has been attributed to the synergistic effects of pseudo-capacitance behavior of the ZnO phase grown on the ZnO seeds and to the nanostructured features of the electrode.

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  • IPEN-DOC 26977

    BONICIO, HERMANO A.; FLORIO, DANIEL de; FONSECA, FABIO C. . Thin layer deposition through Ink Jet technology, for application in SOFC. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 1311-1311.

    Abstract: In the present work, the objective is to develop a film deposition technique with micrometric thickness. For this, the adaptation of a commercial inkjet printer was done by designing and constructing a base with rails so that it runs over the sample. At the same time, a study of rheological characterization of the commercial inks, contained in original ink jet cartridges, was carried out for the development and deposition of a ceramic suspension, which contains the precursors of the desired material for the formation of the thin layer. Finally, some depositions of SOFC electrolytes were performed, and after the densification step, the cells were characterized by the impedance spectroscopy and also scanning electron microscopy. It was observed the formation of a dense and uniform layer, with thickness of the order of 10 μm.

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  • IPEN-DOC 26976

    TINTI, VICTOR B.; FONSECA, FABIO C. ; FLORIO, DANIEL de. A new technique to determine catalysts amounts with ferromagnetic behaviour. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 337-338.

    Abstract: Metallic nanoparticles can be applied at several different areas, from magnetic contrast to fuel production. Nickel is already applied in breaking H-C bounds to the produce H2 for application in SOFC. The miniaturization of the catalyst into nanoparticles can enhance thermal stability and performance. Nowadays, there are some difficulties related to the synthesis, stabilization and characterization of the nanometric system. A new technique to obtain highly disperse nanoparticles consist in the exsolution of previously solubilized ions in a ceramic matrix [1]. Exsolved nanoparticles show higher stability and better catalytic performance, if compared with only deposited particles. The quantization of nanoparticles in the material, using XRD, SEM, TEM or EDS analyses, is not a simple task due limitations of each technic. Magnetic measurements are quick and can provide a precise amount of ferromagnetic particles present in the sample. To demonstrate this technique, samples with compositions (La1-xSrx)(Cr1-yNiy)O3 (x and y = 0, 0.1 and 0.2) were synthesized by complex polymerization method. The morphology of the obtained powder was observed with SEM and TEM. The samples were reduced at 800 °C and 900 °C in pure hydrogen, in order to create metallic nickel nanoparticles by exsolution. Magnetic analyses were conducted with a SQUID/VSM. Reduced samples show a coupling between the ferromagnetic and antiferromagnetic behaviour and a higher temperature of Neel, when compared with thermally treated air. Using as magnetic measurements results was possible to determine higher amounts of Ni, if compared with values obtain from Rietveld refinement.

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  • IPEN-DOC 26975

    SANTIAGO, ELISABETE I. ; MATOS, BRUNO R. ; DRESCH, MAURO A.; ISIDORO, ROBERTA A. ; FONSECA, FABIO C. . Advances on Nafion-based composites for high temperature proton exchange membrane fuel cells. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 55-55.

    Abstract: PEMFC (Proton exchange membrane fuel cell) is considered a promising and efficient hydrogen fuelled electrical power source. However, PEMFC faces several technical problems, such as sluggish electrode reaction kinetics involving the limiting rate of the oxygen reduction and alcohol oxidation reactions, and high resistance to ion transport that could be surpassed with increasing of the operation temperature. The main impediment for such a temperature increase is the water dependent performance of the state-of-the-art Nafion electrolyte. Above 80 ºC water starts to evaporate considerably and Nafion microdomains begin to shrink, disrupting its percolative structure, leading from a conductor to insulator transition. In this work, the incorporation in-situ or ex-situ of an inorganic phase with hydrophilic properties, such as TiO2 and SiO2, into Nafion membranes has been evaluated as an interesting alternative to produce stable electrolytes able to operate at higher temperatures (130o C). The physical-chemistry and electrochemical characterisation has shown that the inorganic particles located in both the nonionic and ionic regions of the ionomer have important contributions to enhanced thermal stability and water uptake. Such features resulted in significant improvements of the PEMFCs using composite electrolytes tested at high operating temperature and low relative humidity. In addition, remarkable enhancement on the DEFC (Direct Ethanol Fuel Cell) performance (122 mW cm‑2) has been obtained as a result of an increase of ethanol oxidation reaction rate promoted by the combination of enhanced catalyst activity and high temperature of operation using stable composite Nafion-SiO2 electrolytes.

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  • IPEN-DOC 26974

    LOBO, RAQUEL de M. ; MORCELLI, APARECIDO E.; SOUZA, SAUL H.; PADILHA, ANGELO F.; ANDRADE, ARNALDO H.P. de . Slant fracture surface in 7075 aluminum alloy tensile specimens. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 800-800.

    Abstract: Rectangular specimen of a 7075 aluminum alloys in three different thermal treatment conditions were tested in a tensile equipment. The samples tested exhibit slant fracture surfaces. Some of the samples presented Portevin-Le Chatelier (PLC) effect. In fact, for aluminum alloys, the PLC phenomenon may occurs even at room temperature. It leads to strain localization and deformation band formation. In this work, the occurrence of slant fracture is studied by scanning electron microscopy and an attempt is done to correlate their presence with the PLC bands.

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  • IPEN-DOC 26973

    BALDAN, RENATO; SILVA, ANTONIO A.A.P.; NUNES, CARLOS A.; COUTO, ANTONIO A. ; GABRIEL, SINARA B.; ALKMIN, LUCIANO. Microstructural changes during solution and aging heat-treatments of MAR-M246 superalloy. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 823-823.

    Abstract: Solution and aging heat-treatments play a key role for the application of the superalloys. The aim of this work is to evaluate the microstructure of the MARM246 nickel-based superalloy solutioned at 1200 and 1250°C for 330 min and aged at 780, 880 and 980 °C for 5, 20 and 80 h. The γ′ solvus, solidus and liquidus temperatures were calculated with the aid of the JMatPro software (Ni database). The as-cast and heat-treated samples were characterized by SEM/EDS and SEMFEG. The γ′ size precipitated in the aged samples was measured and compared with JMatPro simulations. The results have shown that the sample solutioned at 1250°C for 330 min showed a very homogeneous γ matrix with carbides and cubic γ′ precipitates uniformly distributed. The mean γ′ size of aged samples at 780 and 880 °C for 5, 20 and 80 h did not present significant differences when compared to the solutioned sample. However, a significant increasing in the γ′ particles was observed at 980 °C, evidenced by the large mean size of these particles after 80 h of aging heat-treatment.

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  • IPEN-DOC 26972

    MOURA, TIAGO F.A.; NAVARRO, RAPHAELLA; SHIOTSUKI, AUGUSTO K.; UTIYAMA, ANA P.M.S.; ICHIKAWA, RODRIGO U. ; MATOS, RONALDO V.R.; CASTRO, GUSTAVO R.; YOSHITO, WALTER K. ; MARTINEZ, L.G. ; MIRANDA, JOSE R.A.; SAEKI, MARGARIDA J.. The influence of iron content and alkaline concentration on Mn0.75Zn0.25FeyO4 structure, surface charge and acb response. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 578-578.

    Abstract: Nanotechnology applied on magnetic material provide a good opportunity to develop biomaterials as tracers for Alternating Current Biosuceptometry (ACB)and Magnetic Resonance Imaging (MRI) to diagnose certain diseases as cancer. The magnetic nanoparticles can still constitute drug carrier systems and hyperthermia agent for cancer treatment. Neverthless, the efficiency for therapy and diagnosis depends on the magnetic susceptibility. In this work, the ferrite nanoparticles with nominal composition Mn0.75Zn0.25FeyO4, where 1.5 ≤ y ≤ 2.8, were synthesized by the co-precipitation method and, the influence of iron content and concentration of precipitating agent on the structure, ACB response and surface charge was analyzed. It was noted that the synthesis using alkaline metal hydroxide between 0.1, 0.15 and 0.2 mol/L provides single-phase materials [ICSD 28515 (PDF - 742 402), space group Fd3m]. The higher concentration (0.25 mol/L) leads to materials with higher crystallinity and similar ACB response to those precipitated by lower concentration base, despite the secondary phase. A surface charge of 30 mV in module was achieved, which decreased as the concentration of the precipitating agent increased.

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  • IPEN-DOC 26971

    KHAN, LATIF U.; BRITO, HERMI F.; MURACA, DIEGO; COSTA, LUELC S. da; FELINTO, MARIA C.F. da C. . Red-emitting magnetic mesocomposites of Ag-decorated Fe3O4@SiO2 nanoflowers coated with Y2O3:Eu3+: study of iron oxide induced luminescence quenching. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 127-127.

    Abstract: The new multistep approach for co-assembling magnetic iron oxide nanoflowers with red-emitting Y2O3:Eu3+ to form magneto-luminescent mesocomposites was reported. The Fe3O4 core particles prepared by solvothermal method were layered with SiO2 shell and decorated with small size spherical Ag nanoparticles as well as further coated with Y2O3:Eu3+ lluminophore. The nanoflower shape Fe3O4 core of size ~110 nm and crystalline cubic structure of bifunctional ironoxide@ Y2O3:Eu3+, Fe3O4@SiO2@Y2O3:Eu3+ and Fe3O4@SiO2-Ag@Y2O3:Eu3+ (1 mol%) mesocomposites were confirmed from X-rays diffraction, EDS spectra and transmission electron microscopy images. The static magnetic measurements supported and manifested nonsuperparamagnetic behavior of the materials at 300 K. The iron oxides are usually luminescent quencher, therefore, the photoluminescence properties based on the emission spectral data and luminescence decay curves were studied. In addition, experimental intensity parameters (Ωλ), lifetimes (τ), emission quantum efficiencies as well as radiative (Arad) and non-radiative (Anrad) decay rates were also calculated, in order to probe the local chemical environment of the Eu3+ ion and better understand the phenomena of iron oxide induced luminescence quenching. The highest value of the quantum efficiency = 74 %, for the a-Fe2O3@Y2O3:Eu3+ (1 mol%) among all the luminescent and magnetic mesocomposites suggests that Fe2O3 is induced lower luminescence quenching then Fe3O4. Though, the thin layer of SiO2 spacer is caused of increase the quantum efficiency, whereas the Ag is further enhanced the luminescence quenching by energy transfer form Eu3+ ion to the Ag nanoparticles. These novel Eu3+ mesocomposites may act as a red emitting layer for magnetic and light converting molecular devices.

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  • IPEN-DOC 26970

    SERNA, MARILENE M. ; GALEGO, EGUIBERTO ; RAMANATHAN, LALGUDI V. ; FARIA, RUBENS N. . Morphology of nanostructured thin films of ZnO fabricate from SILAR method. In: BRAZIL MRS MEETING, 16th, September 10-14, 2017, Gramado, RS. Abstract... São Carlos, SP: Aptor Software, 2017. p. 1260-1260.

    Abstract: The utilization of the ZnO in the nanotechnology is widely spread due to its superior properties, such as wide direct bang gap (~3.37eV), high exciton binding energy of 60 meV, non-toxicity and low cost [1]. The hexagonal crystalline structure allows obtaining a larger diversity morphologies and this allows its utilization in: UV lasers, piezoelectric crystal, chemical sensor, gas sensor, light emitting diode, photo detectors, and solar cells. One such morphology of ZnO thin film is the one-dimensional (1D) sub-micron rods or nanorods and nanowires, which has attracted interest due to a larger surface area and high aspect ratio. In the solar cell the ZnO has been utilized in the electrode for the dye-sensitized cell in substitution of TiO2. In this study, ZnO nanostructured thin films were prepared by successive ionic layer adsorption and reaction (SILAR) on SnO2-coated glass substrates [2]. In this procedure, the substrate is immersed in successive aqueous baths containing zinc nitrate hydrate and/or hexamethylenetetramine, hydrogen peroxide and triethanolamine. The pH solution was adjusted by addiction of ammonium hydroxide. At a low zinc nitrate concentration of 0.01M the surface is formed by individual nucleus. At a concentration of 0.02 M nanorod arrays were shown and this morphology is of special interest for solar cells application, but the deposition time used in this experiment was insufficient to promote the desired thickness. At a higher concentration of 0.03 M rice like branches morphology was observed but nanorods formation in the flowers was also present. The angular petals suggest that the growth was taken on polar face. For DSSCs applications the thin films prepared in 0.02 M solution was found to be the best choice.

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  • IPEN-DOC 26969

    SANTIAGO, E.I. ; PONCE-GONZALEZ, J.; WANG, L.; VARCOE, J.R.. Células a combustível de membrana de troca aniônica de alto desempenho baseadas em ionômeros sólidos / High performance anion exchange membrane fuel cells based on ionomers. In: SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 21., 17-21 de abril, 2017, Natal, RN. Resumo... Campinas, SP: Galoá, 2017.

    Abstract: Alkaline polymer electrolyte fuel cells (APEFC) have received increased attention in recent years as an alternative to well-established PEMFC because the alkaline medium enables more efficient and faster electrochemical reactions using nonnoble catalysts. The development of stable and conductive polymeric materials employed as anion-exchange membranes (AEM) and anion-exchange ionomers (AEI) has been the focus of substantial efforts. In this work, ETFE (poly(ethylene-cotetrafluoroethylene)) powders were electron-beamed radiation-grafted (RG) with vinylbenzyl chloride (VBC) monomer and then either aminated with trimethylammonium (TMA) or N-methylpyrrolidinium (MPY). The resulting powders were employed as the AEI in the gas diffusion electrodes in single cell H2/O2 APEFCs (along with RG-AEMs). The results showed that the degree of grafting (DoG), and consequently the ionexchange capacity (IEC), are strongly dependent on the radiation dose. RG-AEI made from ETFE irradiated at 100 kGy (total absorbed dose) and functionalised with TMA (ETFE100TMA) and MPY (ETFE100MPY) exhibit IEC values of 2.05 and 1.91 meq.mol-1, respectively. The H2/O2 power density curves (Fig. 1) for APEFC with ETFE100TMA in both anode and cathode; ETFE100MPY in both anode and cathode, and ETFE100TMA in anode and ETFE100MPY in cathode, revealed high performances (> 800 mW cm-2). The best performance was observed for with the ETFE100TMA anode and ETFE100MPY cathode (maximum power density of 1.1 W.cm-2).

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  • IPEN-DOC 26968

    MATOS, B.R. ; SANTIAGO, E.I. ; TOSCO, B.; REY, J.F.Q.; SILVA, J.S. da ; SCHADE, U.; PUSKAR, L.; AZIZ, E.F.; FONSECA, F.C. . Efeito da relaxação do polímero na cristalinidade, fase iônica e formação de grupos sulfônicos anidridos no Nafion / Effect of the polymer relaxation on the crystallinity, ionic phase and sulfonic anhydrides formation of Nafion. In: SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 21., 17-21 de abril, 2017, Natal, RN. Resumo... Campinas, SP: Galoá, 2017.

    Abstract: A relação entre as propriedades estruturais e elétricas de amostras de Nafion preparadas sob tratamento térmico em diferentes temperaturas (220 > T > 100 °C) foi investigada por espectroscopia no infravermelho (FTIR), espalhamento de raios-X em baixo ângulo (SAXS), calorimetria diferencial exploratória (DSC), análise dinâmico-mecânica (DMA) e espectroscopia de impedância (IS). Os resultados combinados de FTIR, SAXS, DSC, DMA revelaram que o tratamento térmico em baixas umidades relativas altera a morfologia do Nafion irreversivelmente devido a três características principais: i) o rearranjo das ligações de hidrogênio; ii) o reordenamento da fase cristalina; e iii) a formação de grupos sulfônicos anidridos. No entanto, a formação dos grupos anidridos é revertida pela reacidificação da membrana em soluções ácidas. O aspecto mais importante da dinâmica dos três processos descritos é que tais alterações são aceleradas acima de uma temperatura crítica: a temperatura de término da transição α do Nafion (Tendα ~ 160 °C). A transição α é atribuída ao enfraquecimento das interações eletrostáticas existentes entre os grupos sulfônicos do Nafion, que permitem a movimentação de longo alcance das cadeias poliméricas [1]. Este resultado indica que a maior dinâmica das cadeias do polímero em T > Tendα é o principal fator envolvido na modificação irreversível da morfologia do Nafion. As alterações da estrutura das ligações de hidrogênio afetaram negativamente as propriedades elétricas do Nafion. O aumento da temperatura de tratamento térmico reduz a condutividade protônica e aumenta a energia de ativação do transporte de cargas no Nafion. Tais resultados são relevantes para a preparação de conjuntos eletrodos-membrana (MEA) e para a operação de células a combustível de eletrólito polimérico (PEFC) em altas temperaturas [1].

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  • IPEN-DOC 26966

    DEETER, MERRITT N.; EMMONS, LOUISA K.; MARTINEZ-ALONSO, SARA; WIEDINMYER, CHRISTINE; ARELLANO, AVELINO F.; FISCHER, EMILY V.; GONZALEZ-ALONSO, LAURA; VAL MARTIN, MARIA; GATTI, LUCIANA ; MILLER, JOHN B.; GLOOR, MANUEL; DOMINGUES, LUCAS G. ; CORREIA, CAIO S. de C. . Progress towards improved MOPITT-based biomass burning emission inventories for the Amazon Basin. In: AMERICAN GEOPHYSICAL UNION FALL MEETING, December 12-16, 2016, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2016.

    Abstract: The 17-year long record of carbon monoxide (CO) concentrations from the MOPITT satellite instrument is uniquely suited for studying the interannual variability of biomass burning emissions. Data assimilation methods based on Ensemble Kalman Filtering are currently being developed to infer CO emissions within the Amazon Basin from MOPITT measurements along with additional datasets. The validity of these inversions will depend on the characteristics of the MOPITT CO retrievals (e.g., retrieval biases and vertical resolution) as well as the representation of chemistry and dynamics in the chemical transport model (CAM-Chem) used in the data assimilation runs. For example, the assumed vertical distribution ("injection height") of the biomass burning emissions plays a particularly important role. We will review recent progress made on a project to improve biomass burning emission inventories for the Amazon Basin. MOPITT CO retrievals over the Amazon Basin are first characterized, focusing on the MOPITT Version 6 “multispectral” retrieval product (exploiting both thermal-infrared and near-infrared channels). Validation results based on in-situ vertical profiles measured between 2010 and 2013 are presented for four sites in the Amazon Basin. Results indicate a significant negative bias in MOPITT retrieved lower-tropospheric CO concentrations. The seasonal and geographical variability of smoke injection height over the Amazon Basin is then analyzed using a MISR plume height climatology. This work has led to the development of a new fire emission injection height parameterization that was implemented in CAM-Chem and GEOS-Chem.. Finally, we present initial data assimilation results for the Amazon Basin and evaluate the results using available field campaign measurements.

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  • IPEN-DOC 26965

    ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; RIBEIRO JUNIOR, IBERE S. ; FAGIONATO, ESNEL A. . On the use of gamma-gamma coincidence to detect very low activities. In: BRAZILIAN MEETING ON NUCLEAR PHYSICS, 40th, September 3-7, 2017, Campos do Jordão, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Física, 2017. p. 1-1.

    Abstract: The detection of very low gamma ray activities is a delicate task, and very important in environmental radiation studies, for instance. It usually requires the use of low-background shielding, as the long counting times required usually make the background subtraction quite tricky, and often result in rather high experimental uncertainties. In this work a different approach is tested, where a two-detector gamma-gamma coincidence system is used to eliminate essentially all of the background continuum - at the cost of reduced overall efficiency and, more importantly, requiring that the radionuclide to be studied presents useful gamma-gamma coincidences. Two distinct methods of analysis are tested, either using an "open-window" coincidence where an event is registered whenever any event is registered in the other detector, or using a strict coincidence analysis, where a valid coincidence between two gamma-rays from the same decay are required; this allow for a discussion on the advantages and problems of each method, as well as for an experimental assessment of the performance of such a system.

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  • IPEN-DOC 26964

    GENEZINI, FREDERICO A. ; ZAHN, GUILHERME S. ; MORALLES, MAURICIO ; MOREIRA, EDSON G. . Celebrating IEA-R1 first criticality. In: BRAZILIAN MEETING ON NUCLEAR PHYSICS, 40th, September 3-7, 2017, Campos do Jordão, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Física, 2017. p. 1-1.

    Abstract: Early in 1956 USP and CNPq established a cooperation agreement and in the middle of the same year, the Atomic Energy Institute (IEA) was founded. Its primary task was to install the research nuclear reactor purchased from the American company Babcock & Wilcox in the context of the “Atoms for Peace” Program. Another major task was to train reactor operators and users of the new facility. The first start-up was in September 16, 1957, being the first criticality achieved in the Southern hemisphere. IEA-R1 is a pool type, light water cooled and moderated, graphite reflected research reactor. Although designed to operate continuously up to 5 MW, it operated at 2 MW power during 40 years and afterwards it has been operating at 5MW. IEA R1 has several uses, such as radioactive isotope production by neutron flux irradiation up to 10(14)cm(-2)s(-1), for health and industry applications; research and development using radioactive samples and neutron beams (8 radial and 2 tangential beam ports). This year we celebrate the 60th anniversary of the first criticality of the IEA-R1 research reactor and due to a continuous modernization program, it is expected to operate for another long time period.

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  • IPEN-DOC 26963

    PASCOAL, ERIC; KLEINGESINDS, EDUARDO; MOURA, ESPERIDIANA ; LUGAO, ADEMAR ; RODRIGUES, RITA. Sugar produced from corncob pretreated with the combination of electron beam irradiation and enzymes. In: AMERICAN CHEMICAL SOCIETY NATIONAL MEETING & EXPOSITION, 253rd, April 2-6, 2017, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Chemical Society, 2017.

    Abstract: Corncob is a lignocellulosic material composed of cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are polysaccharides constituted of simple sugars (hexoses and pentoses). However, these sugars are difficult to access, due to the presence of lignin, which is a polyphenolic molecule that provides a high recalcitrance to plant tissue. An appropriate biomass pretreatment disrupts the hydrogen bonds in crystalline cellulose, breaks down cross-linked matrix of hemicelluloses and lignin, and raises the porosity and surface area of cellulose for subsequent enzymatic hydrolysis. There are several pretreatment methods including, physical pretreatment (electron beam irradiation, grinding and milling, microwave, and extrusion), chemical pretreatment (alkali, acid, organosolv, ozonolysis, and ionic liquid), physico-chemical pretreatment (steam explosion, liquid hot water, ammonia fiber explosion, wet oxidation, and CO2 explosion), and biological pretreatment. This study evaluated electron beam irradiation (EB) in combination with enzymatic hydrolysis on corncob at different grain size to produce sugars. Dry biomass samples after characterization were exposed to EB radiation doses of 0, 30, 50, 70, 100, and 200 kGy. The pretreated biomass samples were enzymatically hydrolyzed using the Cellic CTec2 from Novozymes. The structural changes and degree of crystallinity of the pretreated biomass were studied by FTIR, DRX, DSC, TG and SEM analyses. Corncob in natura showed 6.3 % extractives, 40.3 % cellulose, 31.8 % hemicellulose, 17.3 % lignin, and 0.7 % ash. The EB in combination with enzymatic hydrolysis of corncob is an environmentally sound biomass pretreatment.

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  • IPEN-DOC 26962

    FREITAS, TARIK ; COIADO, RENATA ; LAZO, GISELE; OLIVEIRA, RENE ; MOURA, ESPERIDIANA . Residues from agroindustry as reinforcement in foams based on PBAT/PLA blend. In: AMERICAN CHEMICAL SOCIETY NATIONAL MEETING & EXPOSITION, 253rd, April 2-6, 2017, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Chemical Society, 2017.

    Abstract: Nowadays, agroindustry residues have attracted great attention in both the academic and industrial worlds. In fact, biodegradable polymers reinforced with residues derived from renewable sources, as avian eggshell waste and ashes from the burning of sugarcane bagasse are economically and ecologically attractive materials to produce a new class of bio-products with eco attributes, which make them environmentally friendly, completely degradable and sustainable. In Brazil, the food industry generates every year huge amounts of avian eggshell waste, an industrial byproduct containing 95 % of calcium carbonate, and its disposal constitutes a serious environmental hazard. Tons of ashes are produced from the burning process of sugarcane bagasse to produce energy in Brazilian sugar and bioethanol industries. These ashes, which are not rich in nutrients for the crop, are usually mixed with organic fertilizers or disposed of in nature without efficient management. However, these ashes containing about 94 % of silica. This study aims to the development of bio-foams from PBAT/PLA blend reinforced with bio-calcium carbonate nanoparticles from eggshells and green-silica nanoparticles. Composites were obtained by melting extrusion process, blending PBAT/PLA with 3 % of bio-calcium carbonate nanoparticles and 3 % of green-silica nanoparticles. The composites were then extruded in a Rheomex 332p single special screw for foaming. Samples were submitted to tensile and compression tests, MFI, DSC, XRD and SEM-FEG analyses.

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  • IPEN-DOC 26960

    BARBOSA, HELLIOMAR P.; SILVA, IVAN G.N.; FELINTO, MARIA C.F.C. ; TEOTONIO, ERCULES E.S.; MALTA, OSCAR L.; BRITO, HERMI F.. White light emission materials based on simultaneous Tb3+, Eu3+ and Dy3+ doping in CaWO4 single-phased. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: Tungstates activated by trivalent rare earth ions (RE3+) can be used for many optical devices [1]. Over the last decades, the solid-state lighting sources based on phosphor converted white lightemitting diodes (pc-WLEDs) has improved to overtake fluorescent lighting types because of many advantages such as high ecofriendliness, brightness, low power consumption and fast response time [2]. Here we report preparation and spectroscopic properties of the single phase new highly luminescent white emitting of the Tb3+/Eu3+/Dy3+ triply-doped CaWO4 material. The CaWO4:xTb3+,xEu3+,xDy3+(x mol% of the Ca2+ amount) materials were prepared by fast coprecipitation method at room temperature with stoichiometry aqueous solutions of Na2WO4, CaCl2 and RECl3 (RE3+: Tb, Eu and Dy). The XPD measurements revealed the CaWO4:RE3+ particles belong to the tetragonal scheelite phase with I41/a (#88) space group. The emission spectra exhibit only narrow emission bands arising from the doping Tb3+, Dy3+ and Eu3+ ions. These emission bands are assigned to the 4f transitions from the 4F9/2 (Dy3+), 5D4 (Tb3+) and 5D0 (Eu3+) emitting states to their energy levels corresponding to (in nm): 702 5D07F4(Eu3+), 655 5D07F3(Eu3+), 615 5D07F2(Eu3+), 592 5D07F1(Eu3+), 575 4F9/26H13/2(Dy3+), 544 5D47F5(Tb3+), 488 5D47F6(Tb3+), 478 4F9/26H15/2(Dy3+) (Fig. left). The presence of the emission bands assigned to the doping Dy3+, Tb3+ and Eu3+ ions suggests clear evidence of nonradiative energy transfer from 4F9/2 (Dy3+)5D4 (Tb3+)5D0 (Eu3+) emitter states (Fig. center). The white light emission was mainly reached for 5.0 mol% RE3+ with x: 0.333; y: 0.352 CIE (Commission Internationale l'Éclairage) coordinates (Fig. right). These phosphors could be suitable as triply-doped white light emitters with only single-phased for solid state lighting applications. Since warm white light is preferred for reading, while cold white light is preferred for public lighting the tunability of this single-phase emitting phosphor exhibit promising applications for solid-state lighting.

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  • IPEN-DOC 26959

    FONSECA, THAIS N. ; MOURA, EDUARDO de ; GERALDO, AUREA B.C. . Study of Bixin oxidation by ionizing irradiation. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: Brazil is the world's largest producer of annatto, followed by Kenya and Peru (CORLETT, 2007). The fruit of the annatto tree is constituted by a capsule containing external spines and internal seeds with reddish coloration, providing a natural pigment which is environmentally efficient, being able to replace synthetic pigments and dyes. The active substance of the pigment is Bixin, which is a type of carotenoid which constit utes a greater percentage of pigment in these seeds and has a lipo soluble character ( CUSTODIO , 2002 ). Bixin reacts with NaOH in a saponification reaction giving norbixin, which is water soluble. It is known that the destination of the dye extracted from t he fruit is intended for industry, especially the food industry. The culture of annatto tree brings prospects of development of agricultural programs for medium and small producers, which are able to use decadent areas of other crops. In addition to the fo od sector, new applications for the pigment helps the development of family farming (BERTOLIN, 2016). The pigment extracted from annatto undergoes a natural oxidation; this work aims to evaluate this phenomenon and also the oxidation of the pigment after the irradiation process. This work also evaluates of the how the oxidation process is affected by irradiation and the modifications introduced to irradiated pigments. Irradiated and non irradiated samples were characterized by UV vis s pectrophotometry a nd infrared spectroscopy (FTIR). The results are then discussed.

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  • IPEN-DOC 26958

    TEIXEIRA, PAULA dos S. ; MOURA, EDUARDO de ; GERALDO, AUREA B.C. . Irradiation of cellulosic waste from annatto seeds (Bixa orellana L.) for application in polymeric composites. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: The study o f natural vegetable, fiber reinforced polymeric composites became popular in the last decades since because this type of material enables the reduction of both the biomass waste and the cost of the final polymer product (MARINELLI, 2008). Plant fibers are plenty, low cost, they feature biodegradability and renewability. Moreover, cellulose polymer composites are more resistant to flection and impacts than the same base polymer material (FONSECA, 2005; HILLIG, 2008). Specifically, cellulose from annatto seed s is present in concentration at around 40 45%, which becomes important for industrial use (ANSELMO, 2008). In this work, the bagasse from annatto seeds after reddish pigment removal has being used to obtain high density polyethylene (HDPE) composites. T he original raw material underwent a pretreatment that extracted the components from seeds such as residue of remaining pigment, sugars, proteins and acid fats. The remaining fibers have been dried and mashed, and then submitted to electron beam irradiatio n with doses of 30 kGy, 50 kGy and 70 kGy to verify the effect of the radiation on the cellulose structure and its subsequent effect on the incorporation into polymer matrix. The study covered the extrusion of these fibers (irradiated and non irradiated) i n the ratio of 1 % to 5 % with HDPE. The sample characterization has been done by infrared spectrometry (FTIR), thermal degradation (TG) and mechanical tensile tests. The results are then discussed.

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  • IPEN-DOC 26957

    FERREIRA, MAIARA S. ; MOURA, EDUARDO de ; GERALDO, AUREA B.C. . Effect of irradiation on the molar mass of chitosan from crab shells of Charybdis hellerii. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: The importance of determining the molar mass of polymers is closely related to the size of the chain which is a controlling factor in the evolution of solubility, elasticity, fiber formation and mechanical strength properties. There are several methods used to determine the molar mass and they are divided into relative or absolute. Relative methods as viscosimetry require calibration with samples of molar mass known, whereas absolute methods as osmometry do not require it. The importance of molar mass determination is related to its high influence on the properties of chitosan, such as bacterial activity. There are some studies that show that the use of chitosan is more efficient in the inhibition of bacteria than the use of the oligomers that form the same (NO et al., 2002; HIRANO et al., 1989) and that the molar mass required for the inhibition of microorganisms should be greater than 10000 Da (SHAHIDI et al., 2000). The minimum inhibitory concentration of chitosan ranges from 0.005 - 0.1% and depends on the species of bacteria, the molar mass and the pH of the chitosan preparation (GUAN et al., 2001, NO et al., 2002). The method used in this work was the capillary viscosimetry because it is simple, fast and very efficient. For each sample, four dilutions were performed in order to make the extrapolation and determine the intrinsic viscosity. The average viscosity molar mass (Mw) was determined by the Mark-Houwink-Sakurada equation ([ƞ] = KMav). As one of the results it was observed that the chitosan coming from the crab shell is of low molar mass with a value correspondent about 10 times smaller when compared with the standard. The chitosan obtained with the use of electron beam irradiation also shows a decrease in the molar mass as a function of the increase of the absorbed radiation dose.

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  • IPEN-DOC 26956

    GABRIEL, LEANDRO ; MOURA, EDUARDO ; GERALDO, AUREA B.C. . Crystallinity and mechanical properties of recycled, gamma irradiated HDPE/EPDM blends. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: High Density Polyethylene (HDPE) is a commodity and its wide range of uses comprises several plastic processing in the industry due its conformability, high thermal and chemical resistance and a relative low cost [1]. Also, this material can be recycled many times, which is an important characteristic to decrease the environmental impact when plastic goods reach their end of life. EPDM is one of thermosetting elastomers widely applicated in automotive industry because of its high mechanical, thermal and ageing resistance [2]. The mixture of this both components generate a material with high impact resistance and tensile strength at break [3]. HDPE/EPDM blends are obtained by extrusion of these polymeric components with addition of compatibilizers agents to achieve a homogenous and compatible mixture [4]. In this work the High Density Polyethylene (HDPE) matrix has been recycled four times from original substrate and mixed to non-vulcanized EPDM rubber in proportions from 1 % to 10 % with no addition of compatibilizer agents. The gamma irradiation process was applied at 50 kGy and 100 kGy to both original and recycled blend samples. Characterization of samples was performed by X-ray diffraction and stress-strain assay. These results showed an increase of degree of crystallinity at recycled non-blended HDPE compared to this same parameter to pristine HDPE. It was also observed that crystallinity decreases as EPDM concentration increases. In irradiated samples, this parameter increase with high absorbed doses. The crystallite grain size increases in EPDM concentration from 1 % to 5 %; however, this parameter decreases in blends with 10 % of EPDM contents. This behavior suggests a co-crystallization effect on each polymeric component present in the blend and it may explain the miscibility and compability of both components in this material without addition of other agglutinative substances. The parameter stress at yield is high in pristine HDPE and low in recycled HDPE; this parameter decreases with as EPDM concentration increases in the non-irradiated polymeric blend. In irradiated blends the stress at yield increases in high doses. The irradiation process promotes blend crosslinking, and it is evident in blends with high EPDM concentration where high stress at 100 % strain is observed.

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  • IPEN-DOC 26955

    BEZZAN, OTAVIO P.; PEDROSO, CASSIO C.S.; CARVALHO, JOSE M.; FELINTO, MARIA C.F.C. ; BRITO, HERMI F. ; RODRIGUES, LUCAS C.V.. Discovering new colors of luminescence in rare-earths doped CaTiO3 through co-doping. In: WORLD CHEMISTRY CONGRESS, 46th; ANNUAL MEETING OF THE BRAZILIAN CHEMICAL SOCIETY, 40th; IUPAC GENERAL ASSEMBLY, 49th, July 07-14, 2017, São Paulo, SP. Abstract... Durham, NC, USA: International Union of Pure and Applied Chemistry, 2017.

    Abstract: The luminescence of CaTiO3:Pr3+ has been known since mid-90s [1] and its persistent luminescence has been explained via InterValence Charge Transfer transitions [2]. However, the trivalent dysprosium doped materials besides presenting white luminescence does not present any persistent luminescence. On the other hand, the expected red emission on materials doped with Eu3+ only occur when exciting in the forbidden 4f6-4f6 transitions. The objectives of this work are to show the synthesis and luminescence properties of CaTiO3:Dy3+ and CaTiO3:Dy3+,R3+ prepared with the sol-gel method [3, 4]. The excitation spectra of single Eu3+ or Dy3+ doped materials (Fig. left) show for Eu3+, only the 4f6-4f6 transitions while for Dy3+ both the 4f9-4f9 transitions as well as the O2-→TiIV charge transfer and the host absorption. The excitation spectrum for the Dy3+,Eu3+ co-doped material monitoring the Eu3+ emission at 610 nm exhibit both the Eu3+ intraconfigurational transitions as well as the O2-→TiIV charge transfer and the host absorption. This result indicates that there is no direct energy transfer from Dy3+ to Eu3+, but Dy3+ acts as a sensitizer for Eu3+ to be excited by host transitions. Based on experimental data the energy level diagram was constructed (Fig. right) showing that Eu3+ is deep inside the valence band.

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  • IPEN-DOC 26952

    GUEDES-SILVA, C.C. ; RODAS, A.C.D.; RIBEIRO, C.; HIGA, O.Z. ; FERREIRA, T.S. . Estudo da bioatividade, adesão e proliferação de osteoblastos em biocompósitos de nitreto de silício. In: CONGRESSO DA SOCIEDADE LATINO AMERICANA DE BIOMATERIAIS, ORGAOS ARTIFICIAIS E ENGENHARIA DE TECIDOS, 14.; EDICAO DO WORKSHOP DE BIOMATERIAIS, ENGENHARIA DE TECIDOS E ORGAOS ARTIFICIAIS, 5., 20-24 de agosto, 2017, Maresias, SP. Abstract... 2017. p. 584-584.

    Abstract: Este estudo avalia o comportamento biológico in vitro de cerâmicas de nitreto de silício denso contendo sílica, cálcia e alumina como constituintes da fase vítrea. Experimentos de bioatividade em SBF e testes de adesão e proliferação de celular com células MG-63 foram realizados nas superfícies das amostras. Os resultados mostraram que os materiais estudados formaram uma camada de apatita na superfície após 16 dias de imersão em SBF e que são capazes de promover a proliferação de osteoblastos e formação de matriz calcificada in vitro, demonstrando seu potencial para aplicações como dispositivos protéticos.

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  • IPEN-DOC 26950

    NUNES, R.M. ; COSTA, D. ; SOUZA, S.B.R. de ; ORTIZ, N. . The comparison of charcoal activation processes using methylene blue adsorption: removal percentage and surface coverage area. In: IWA LEADING EDGE CONFERENCE ON WATER AND WASTEWATER TECHNOLOGIES, 14th, May 29 - June 02, 2017, Florianópolis, SC. Resumo expandido... London, UK: International Water Association, 2017.

    Abstract: A series of activation processes was performed on charcoal waste to absorb and remove methylene blue (MB) from polluted waters. The results were used to calculate the MB removal percentage and the surface coverage area. Both aspects are important indication of the activation process efficiency. The activated process with potassium chloride, potassium carbonate and water stream showed high adsorption efficiency with removal percentage of 90, 84 and 79% respectively and 24.5, 24.0 and 18.9 of m2 g-1 of surface cover area (θ) such surface area increment was considered an important aspect to evaluate the promising properties of activated charcoal to be use in water treatment plant.

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  • IPEN-DOC 26949

    SOUZA, S.R.B. ; COSTA, D. ; NUNES, R.M. ; ORTIZ, N. . Using charcoal micronized carbon (MEC) to methylene blue adsorption: the isotherm calculations. In: IWA LEADING EDGE CONFERENCE ON WATER AND WASTEWATER TECHNOLOGIES, 14th, May 29 - June 02, 2017, Florianópolis, SC. Resumo expandido... London, UK: International Water Association, 2017.

    Abstract: A comparison of different isotherm calculations was performed using micronized eucalyptus charcoal (MEC) absorbing methylene blue. The dye wastewater could affect in large scale the surface water quality and the metabolism of many species. The micronized charcoal was able to remove about 75% for the dye accordingly with Langmuir, Freundlich and Redlich-Peterson isotherm calculations suggesting a promising new, efficient and low cost water treatment process.

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  • IPEN-DOC 26943

    QUINI, JOSUE G.; MARINUCCI, GERSON . Analysis of structural adhesives for automotive applications. In: GOMES, J.F.S. (Ed.); MEGUID, S.A. (Ed.) INTERNATIONAL CONFERENCE ON MECHANICS AND MATERIALS IN DESIGN, June 11-15, 2017, Albufeira, Portugal. Resumo expandido... Porto, Portugal: INEGI/FEUP, 2017. p. 1353-1354.

    Abstract: Structural adhesives technology has changed the concept of joints bonding different materials in a unique solid assembly and making them part of the structures. These joints not only increase strength and stiffness but also reduce weight, which is important, for instance, for vehicles and airplanes. The present study reports the results of applying urethane structural adhesives in automotive components. Lap shear in joints formed by polymeric composites, such as RTM and SMC, ABS thermoplastic and galvanised steel, was evaluated. The results show very good adherence between the adhesive and the substrates under different temperature conditions and relative humidity.

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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.