Eventos - Resumos: Recent submissions

  • IPEN-DOC 26799

    BIANCOLLI, A.L.G.; LOPES, T. ; PAGANIN, V.A.; TICIANELLI, E.A.. Electrocatalysts and membranes for using in PEMFCs and AEMFCs fed by contaminated hydrogen. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 417-417.

    Abstract: Catalytic ethanol dehydrogenation has been proposed as a promising method to produce H2 without CO and CO2.¹ However, the dehydrogenation generates other types of organic by-products such as ethyl acetate, acetaldehyde and leaves unreacted ethanol that can cause power losses in the fuel cell. To make this technology accessible, fuel cells performances must be improved. In this context, we studied the influence of the main contaminants present in the hydrogen produced by the catalytic dehydrogenation of ethanol on the performance of proton exchange membrane fuel cells (PEMFCs) and anion exchange membrane fuel cells (AEMFCs). Investigations comprised the elucidation of the processes and reactions involved in the corresponding electrode systems, as well as the phenomena governing the electrochemical performance in the alkaline and acidic media, and in the absence and in the presence of the by-products. For the AEMFCs, the research initially involved the syntheses of ionomers and membranes and the optimization of their performances in single cells, using pure hydrogen and conventional electrocatalysts (Pt-Ru/C in the anode and Pt/C in the cathode).² However, due to the chemical instability when exposed to the contaminants, these materials seem to undergo degradation, leading to almost total and irreversible losses of the cell performance. A positive fact was that AEMs showed much less crossover of contaminants from the anode to the cathode. Through analyses by different techniques, it was found that unreacted ethanol is the main poison in the case of PEMFCs, with acetaldehyde and ethyl acetate having minor contributions. Different anodic and cathodic catalysts were tested in order to obtain better fuel cells performances, such as Pt-Sn/C, Pt- W/C, Pt-Co/C, Pt-Cr/C and Pt/C (Fig. 1). Also different types of membranes were tested (Nafion® 115, 117, and 212). The best result was achieved when the Pt- Co/C catalyst was used at the cathode (with Pt/C at the anode), for which the loss of power density was only 20% compared to a cell fed by pure H2 and with Pt/C on both electrodes (working at 0.7 V).

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  • IPEN-DOC 26798

    SILVA, R.P. ; SOUZA, R.F.B. de ; SANTOS, C.M.G. ; SILVA, A.J. ; SANTIAGO, E.I. . Development of non-fluorinated membranes based on PBI for application in high temperature fuel cells (HT-PEM). In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 460-460.

    Abstract: Most of Proton Exchange Membrane Fuel Cells (PEMFCs) use the Nafion as electrolyte, which has a limitation in the operating temperature. Usually, these cells operate up to 80°C since the proton conduction is dependent on water molecules carriers. The increase in the operating temperature of a PEMFC cell is desired due to the contribution of the temperature in the acceleration of the electrochemical reactions, which are thermoactivated processes. In the context of searching alternative polymeric electrolytes, PBI (polybenzimidazole) membranes have been considered a promising membrane for high temperature operating PEMFC (HT-PEMFC) due to the combination of satisfactory proton conduction in conditions of low relative humidity (RH) and excellent thermal stability. Pure PBI membranes were prepared by casting a solution of PBI / N, N'-dimethylacetamide (DMAc) and doped with phosphoric acid at different times (1, 3, 5, 7 10 and 15 days). Each membrane was evaluated in Fuel Cell tests, doping level and online Raman tests in order to determine effects of doping level, chemical degradation and fuel cell performance. The electrodes were optimized by studying different catalytic layer composition and the cell tested at different operational conditions.

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  • IPEN-DOC 26797

    GUIMARÃES, V.P.; NANDENHA, J. ; FATIBELLO-FILHO, O.; NETO, A.O. ; VICENTINI, F.C.; ASSUMPÇÃO, M.H.M.T.. Development of nanomaterials for formate electrochemical oxidation aiming sustainable energy generation. In: ANDRADE, ADALGISA R. de (Ed.); ALMEIDA, ERICA J.R. de (Ed.); OLIVI, PAULO (Ed.) SIMPÓSIO BRASILEIRO DE ELETROQUÍMICA E ELETROANALÍTICA, 22nd, 1-5 de setembro, 2019, Ribeirão Preto, SP. Resumo... Ribeirão Preto, SP: Sociedade Brasileira de Eletroquímica e Eletroanalítica, 2019. p. 436-436.

    Abstract: The world energy system is highly depended of fossil fuels, which is not sustainable [1]. Thus, the use of alternative energy is crucial and fuel cells are being considered good options. In this context, this work aimed to develop electrocatalysts based on palladium nanoparticles (PdNPs) supported on the physical mixtures of carbon (Vulcan XC72) and titanium dioxide (P25) toward formate oxidation in alkaline medium and its application in formate fuel cells. The materials were synthesized by the borohydride reduction method [2] with 20% (m/m) of metal loading and in two batches. In the first batch, the PdNPs were reduced in the physical mixture of carbon (C) and titanium dioxide (TiO2), in different proportions of C and TiO2, identified as Pd/(C+TiO2), while in the second one, the PdNPs were reduced only in TiO2 with later incorporation of C which were identifies as Pd/TiO2-C. On both batches, the ratios between C and TiO2 used were 75:25, 50:50 and 25:75 (m/m). A reference material, complied of PdNPs supported just on C (Pd/C) was also prepared. All materials were characterized by X-ray diffraction, showing peaks of the face-centered-cubic (fcc) structure of the Pd, as well as TiO2 peaks of anatase and rutile phases. Transmission Electron Microscopy (TEM) were also evaluated showing an average particle size between 3 and 8 nm. Electrochemical experiments considering voltammetry and chronoamperometry showed that the materials with PdNPs reduced in the TiO2 (Pd/TiO2-C) were more promising when compared to Pd/(C+TiO2), and among them Pd/TiO2-C 75:25 presented the highest current observed in chronoamperometry. Comparing the Pd/(C+TiO2) materials, the Pd/(C+TiO2) 50:50 presented the highest current. Taking into account single cell experiments, although the electrochemical results evidenced the improvement toward formate with PdNPs deposited firstly in the TiO2, the fuel cell tests showed the opposite, presenting the best cell efficiencies with Pd/(C+TiO2) materials, where Pd/(C+TiO2) 75:25 (ratio between C and TiO2) was the best material with the highest power density obtained. This fact can be explained by the higher conductivity of C, in a higher proportion, coupled with the small amounts of TiO2, which provides oxygenated species that facilitate the formate oxidation.

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  • IPEN-DOC 26796

    ZAMBONI, CIBELE B. ; ALMEIDA, MATEUS R. de ; MEDEIROS, JOSE A.G. de. Análise de zinco em sangue de corredores de longa distância / Zinc analysis in blood of long-distance runners. In: CONGRESSO BRASILEIRO DE CIÊNCIAS DO ESPORTE, 21st; CONGRESSO INTERNACIONAL DE CIÊNCIAS DO ESPORTE, 8th, September 15-20, 2019, Natal, RN. Resumo expandido... Porto Alegre, RS: Colégio Brasileiro de Ciências do Esporte, 2019.

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  • IPEN-DOC 26795

    ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. ; MORALLES, MAURICIO . Evaluation of peak-fitting software for gamma spectrum analysis. In: REUNIÃO DE TRABALHO SOBRE FÍSICA NUCLEAR NO BRASIL, 42.; ENCONTRO NACIONAL DE FÍSICA DE PARTÍCULAS E CAMPOS, 40., 1-5 de setembro, 2019, Campos do Jordão, SP. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2019.

    Abstract: In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width, for instance, are associated with each peak of each spectrum. Theres a huge choice of computer programs that perform this type of analysis, and the most commonly used in routine work are the ones that automatically locate and fit the peaks; this fit can be performed in several different ways - the most common are either to fit a Gaussian function to each peak or simply to integrate the area under the peak, but some software go far beyond and include several small corrections to the simple Gaussian peak function, in order to compensate for secondary effects. In this work several gamma-ray spectroscopy software are compared in the task of finding and fitting the gamma-ray peaks in spectra taken with some calibrated standard sources. The results allow for a discussion on the performance of each software in the tasks of identifying and determining the correct area of the gamma-ray peaks, as well as on the advantages and difficulties in using automatic programs when comparing with a manual peak-fitting software, used as reference.

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  • IPEN-DOC 26794

    ZAMBONI, CIBELE B. ; GIOVANNI, DALTON N.S. ; MIURA, VINICIUS T. ; GOMEZ, MONICA R. . Identificação de processos fotográficos utilizando a técnica de FRX. In: SIMPOSIO LATINOAMERICANO DE FÍSICA Y QUÍMICA EN ARQUEOLOGÍA ARTE Y CONSERVACIÓN DE PATRIMONIO CULTURAL, 7th, September 9-13, 2019, Ciudad de México, México. Abstract... Ciudad de México, México: Universidad Nacional Autónoma de México, 2019. p. 7-7.

    Abstract: O conhecimento da composição elementar de artes gráficas é de grande interesse para investigações de caráter histórico-artístico na medida em que possibilita identificar o processo de produção, a época de sua manufatura e, em alguns casos, sua procedência. Nos últimos anos, no Brasil, essas investigações têm adquirido relevância e estão sendo empregadas em acervos fotográficos pertencentes a museus, galerias de artes e a colecionadores particulares. As primeiras fotos tomadas em solo brasileiro datam de 1840 época da daguerreotipia. Desde então, com seu aperfeiçoamento, a fotografia tomou lugar de relevância cultural e viabilizou a geração de acervos particulares, sendo que muitos necessitam de devida caracterização, afim de situar o “objeto” dentro do contexto de sua própria época, além de agregar informações que auxiliem sua conservação e preservação. Atualmente a peritagem de obra de arte está crescendo no Brasil, em decorrência, estas informações podem agregar também valor econômico às produções gráficas. No presente estudo, o material de estudo compõe duas coleções fotográficas: uma com foco na arquitetura paulistana, e outra retratando personalidades do meio artístico. São acervos particulares cuja data e o processo de produção não são conhecidos. As análises de Fluorescência de Raios X por Dispersão de Energia (FRXDE) foram realizadas Laboratório de Espectroscopia e Espectrometria das Radiações (IPEN/CNEN-SP, Brasil), utilizando espectrômetro portátil de FRX da Amptek® com alvos de prata (Ag) e ouro (Au). Este instrumental é constituído por um detector de Silício Drift XR-100SDD (25 mm2 x 500 μm) com janela de Berílio (12,5 μm), acoplado a um pré-amplificador, um processador de pulso digital e multicanal. A condição de excitação foi estabelecida por 5 μA e 30 kV com tempo de contagem de 120 s. A análise elementar da coleção referente à arquitetura paulistana evidenciou o uso papeis com revestimento barita, muito utilizado por fotógrafos profissionais e amadores entre 1889-1930, evidenciam que essas fotos foram registradas entre o fim do século XIX e início do século XX. No que diz respeito ao acervo dos retratos, foi identificado o processo de cianotipia, evidenciado pela coloração azul das fotos (devido ao emprego sais de ferro como substância fotossensível), muito popular nas últimas décadas do século XIX [1,2]. Os resultados disponibilizados pela técnica de FRXDE permitiram situar a época e os processos fotográficos empregados. Essas informações contribuem para valorização desses acervos além de fornecer subsídios para o correto armazenamento e preservação.

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  • IPEN-DOC 26793

    BOIANI, N.F. ; SILVA, T.T. ; BORRELY, S.I. . Toxicity assessment of caffeine, fluoxetine and their mixture on Daphnia similis: acute and cronic effects. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 109-109.

    Abstract: Emerging pollutants have already become a global problem, and they have been detected in dozens of countries, including Brazil. Even at very low concentrations, most of the emerging compounds are able to induce changes into biochemical system of aquatic organisms and they have also been reported as negative products to human health. Pharmaceuticals are considered as emerging contaminants detected in estuarine environment, in wastewater treatment facilities, lakes and rivers and even in sea waters. Generally the pharmaceuticals are detected among many other compounds into the ecosystem. The interaction of mixtures of contaminants is an important issue to be considered in monitoring programs as well as the negative effect to aquatic biota. The aim of the present paper was the assessment of toxic effects of pharmaceuticals exposed to Daphnia similis crustacean, individual and combined mixture of caffeine and fluoxetine. Caffeine (CAF) is a stimulant with cardiac, cerebral, diuretic and respiratory effects while Fluoxetine (FLX) is a selective serotonin re-uptake inhibitor, widely prescribed as antidepressant, (also known as Prozac®). The juveniles of D. similis were exposed separetaly to both caffeine (100mg/L) and to fluoxetine (20mg/L), and to a mixture of both (50mg/L caffeine and 20mg/L fluoxetine). Several experimental trials of acute immobilization test were performed. EC50 values ranged from 29,7 to 31 mg/L-1 for caffeine, and from 1.0 to 1.4 mg/L-1 for fluoxetine. Antagonistic effects of binary mixtures (EC50 = 15.2%) were observed. A chronic reproduction test was performed for the mixture of pharmaceuticals. We observed effects on D.similis survival, after 5 days. The mixture led to decrease of 72% in the reproduction, in maximum concentration (2.5% of the mixture – CAF 50ppm + FLX 20ppm). Concerning the importance of assessing toxicity the elected pharmaceuticals concentration were higher than those detected in the envinroment. These results may be incorporated into risk assessments analysis in order to protect sensitive aquatic ecosystems more effectively.

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  • IPEN-DOC 26792

    TOMINAGA, F. ; BOIANI, N.F. ; SANTANA, N.D.; BORRELY, S.I. . Acute toxicity assessment for binary and tertiary mixtures containing fluoxetine, propranolol and diclofenac to microcrustacean and zebrafish embryos. In: SOCIETY OF ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY (SETAC) LATIN AMERICA BIENNIAL MEETING, 13th, September 15-18, 2019, Cartagena, Colombia. Abstract... Pensacola, FL, USA: Society of Environmental Toxicology and Chemistry, 2019. p. 111-112.

    Abstract: Pharmaceuticals are essential for treatment and prevention of several diseases and for the maintenance of human and animal’s life quality. Due to the increasing use of pharmaceuticals worldwide, many actives substances are currently detected in μg.L-1 and ng.L-1 in different environmentals matrices such as surface water, ground water, soil and sediment. Many of these emerging pollutants are recalcitrant to biological treatment process in WWTPs and they may cause ecotoxicological effects on organisms and also possible to reach the human food chain. Pharmaceuticals are frequently detected as mixtures and may induce toxic effects to aquatic organisms, producing synergistic, additive or antagonistic toxic effects. Fluoxetine hydrochloride (FXT) is a selective serotonin reuptake inhibitor, prescribed as an antidepressant. Propranolol (PRP) is a beta-adrenergic blocker widely prescribed for the treatment of cardiovascular diseases and diclofenac sodium (DIC) is a non-steroidal anti-inflammatory drug, often recognized as the “world’s most popular pain killer”. These compounds are worldwide used for healthy treatment and also often detected in aquatic environments. This work aims to assess the toxicity of three pharmaceutical individually and in a mixture for both Daphnia similis and zebrafish embryos. The results of individual acute toxicity showed that the microcrustacean was more sensitive to FXT (EC50 = 1.08 mg/L), PRP (EC50 = 5.92 mg/L) and DIC (EC50 = 25.0 mg/L), respectively, while for zebrafish embryos, it was only calculated LC50 of 30.5 mg/L for DIC, after 48h exposure. Antagonistic effects of binary mixtures of FLX + PRP (EC50 = 9.38%) and FXT + DIC (EC50 = 24.2%) were observed to D. similis. For Danio rerio embryos, binary mixture of FLX + DIC (LC50 = 82.1%) presented antagonistic effects, while no acute toxicity was observed for the of FXT + PRP mixture. Tertiary mixture of the three compounds showed an antagonist effect (EC50 = 5.57%) for the microcrustacean and additive effect for zebrafish embryos (LC50 = 87.5%). In conclusion, most of the binary mixture resulted in antagonistic effects, in which the response of acute toxicity depended on the organism and type of pharmaceutical mixture. Therefore, it is necessary further studies to assess the toxicity of different mixtures.

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  • IPEN-DOC 26780

    ZUFFI, ARMANDO V.F. ; ALMEIDA, ANDREIA A. ; VIEIRA JUNIOR, NILSON D. ; SAMAD, RICARDO E. . Development of glass nozzles for below threshold harmonics and high harmonic generation. In: FRONTIERS IN OPTICS; LASER SCIENCE CONFERENCE AND EXHIBITION, 15-19 September, 2019, Washington, DC, USA. Resumo expandido... Washington, DC, USA: OSA, 2019.

    Abstract: This work reports development of glass nozzles by ultrashort laser pulses machining for studies of harmonic generation in gases. Those nozzles generated odd harmonics (3rd up to 25th) in UV and VUV regions.

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  • IPEN-DOC 26779

    TOMINAGA, F.K. ; SILVA, T.T. ; JESUS, J.M.S. de; BOIANI, N.F. ; TEIXEIRA, A.C.S.C.; BORRELY, S.I. . Effect of electron beam irradiation on mineralization and toxicity of aspirin. In: IBEROAMERICAN CONFERENCE ON ADVANCED OXIDATION TECHNOLOGIES, 4th; ISE SATELLITE STUDENT REGIONAL SYMPOSIUM ON ELECTROCHEMISTRY, 7th, November 18-22, 2019, Natal, RN. Resumo expandido... 2019. p. 1-3.

    Abstract: Electron Beam Irradiation (EBI) is an important technology for degradation, mineralization and detoxification of pollutants. In this work, total organic carbon (TOC) and toxicity was evaluated for aspirin after Electron Beam Irradiation at doses of 1.0, 2.5 and 5.0 kGy. Low mineralization was achieved at all applied doses. Toxicity increase and hydrogen peroxide formation was observed with the increase of absorbed dose. EBI can be an interesting alternative process applied as a pre-treatment for alternatives AOPs.

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  • IPEN-DOC 26778

    ROSSI, WAGNER de ; HERRERA, CRISTHIANO da C.; GOMES, ANTONIO A. ; BALDOCHI, SONIA L. . Femtosecond laser micromachining of microfluidic components in BK7 optical glass. In: EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES, September 1-5, 2019, Stockholm, Sweden. Abstract... Boutersem, Belgium: Federation of European Materials Societies, 2019. p. 898-898.

    Abstract: Introduction/Purpose The objective of this work was the development of micromachining with femtosecond laser in BK7 optical glass for the production of components of microfluidic devices. The aim was to produce microchannels, microvalves, micropumps, mixers and a localized heater, which can be arranged in any way to produce microfluidic devices on demand. Methods The structures were machined on the surface of BK7 glass plates, with the use of ultrashort laser pulses of a Ti:sapphire system on a high precision displacement stage and numerical control program. The first step was to obtain a set of process parameters suitable for efficient and accurate machining that would result in a smooth surface with no collateral damage to the neighboring region. Results Microvalves were machined with these optimized parameters, and when powered by pneumatic drive and managed by a dedicated software presented a flow control of less than 1 nl/s. These microvalves were used together to produce micrpumps to control flows in regions where external pressure can not be achieved. Mixers are also being developed for single phase systems and for biphasic systems. A machine vision system is being used to characterize both systems. Color analysis for single phase mixers and bubble analysis for biphasic ones. An innovative localized heating system was developed for temperature control in microreactors. For this, a tiny metal blade was textured with fs laser where light absorptive nanostructures were obtained. The slide was introduced into a microreator that had its temperature controlled through the focusing of an external source of light on its surface. With this, it was possible to control temperature above 100°C inside the microreator. Conclusions With the developed components, some microfluidic systems were built. In particular, a system for synthesis of NaYF4 nanocrystals and for ELISA assays will be presented.

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  • IPEN-DOC 26777

    FREIRE, L.O. ; ANDRADE, D.A. de . The four functions of elementary pipe design from constructal law. In: CONSTRUCTAL LAW AND SECOND LAW CONFERENCE, March 11-13, 2019, Porto Alegre, RS. Resumo expandido... 2019. p. 1-4.

    Abstract: Constructal law explains the sense of evolution (morphing to improve flows) of beings, but paradoxes do exist as not all vegetables have a tree form. Also, not all animals are optimized for displacement. This work aims at identification of the design functions or objectives that guide evolution under the overall statement of constructal law. This work adopted the system engineering technique of segregation between functions (abstract objectives) and solutions (physical entities). Further, this work introduced the assumptions of flow under external threats and pipes subject to leakages. Results showed that there are always elements doing four functions in pipe element: to reduce flow entropy, to protect flow channel, to retain flow content and to increase flow drive. Although the four functions are always present, natural systems typically privileges some functions over others, depending on environmental pressures. As a solution to improve flows, animal brains also fit in the model of four functions. Human mind seems to have groups of instincts associated to each of the four pipe design functions (fear, attachment, curiosity and greed). Finally, the four functions model unified physics and animal psychology.

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  • IPEN-DOC 26776

    GATTI, LUCIANA; MILLER, JOHN B.; BASSO, LUANA S.; DOMINGUES, LUCAS G. ; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO S. de C. ; IPIA, ALBER; ARAI, EGIDIO; TEJADA, GRACIELA; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA O.; VON RANDOW, CELSO; GLOOR, MANUEL; PETERS, WOUTER; NEVES, RAIANE A.L.; CRISPIM, STEPHANE P.. Amazon carbon balance and its sensitivity to climate and human-driven changes. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: The Amazon accounts for 50% of Earth’s tropical rainforests hosting the largest live carbon pools in vegetation and soils (~200 PgC). The net carbon exchange between tropical land and the atmosphere is critically important, because the stability of carbon in forests and soils can be disrupted on short time-scales. The main processes releasing C to the atmosphere are deforestation, fires and changes in growing conditions due to increased temperatures and droughts. Such changes may thus cause feedbacks on global climate. In the last 40 years, the Amazon mean temperature has increased by 1.1ºC. Annual mean precipitation has also decreased by 51 mm during this same 40 year period. The precipitation reduction occurred mainly in the dry season, and the dry season has lengthened, exacerbating vegetation water stress with consequences for carbon balance. To better understand its C budget, starting in 2010 we established a regionally representative greenhouse gas monitoring program across Amazonia. The program aims to quantify gas concentrations (CO2, CH4, N2O, CO, and SF6) based on extensive collection of air from light aircraft vertical profiles. The atmosphere is profiled from the ground up to 4.5 km height at four sites along the main air-stream over the Amazon Basin on a twice-monthly basis. Here we will report what these new data tell us about the carbon balance and its controls from 2010-2017. During this period we performed 513 vertical profiles over four strategic regions that represent fluxes over much of Amazonia. The observed variability of carbon fluxes during these 8 years is correlated with climate-related (temperature, precipitation, soil water storage from GRACE satellite) and anthropogenic (fire counts) variables. The correlations were performed inside the upwind area for each profiling site. During our study period, the Amazon was a consistent source of 0.4 ± 0.2 PgC/year on average, extrapolating to the entire Amazon Basin area of 7.2 million km2. Fire emission is the main source of carbon to the atmosphere, which is not compensated by the C removal from old-growth Amazon forest. Moreover, the drought years of 2010, 2015 and 2016 are playing an outsized role in the eight-year mean. Removing those years from the mean, the net source is reduced from 0.4 ± 0.2 PgC/year to 0.2 ± 0.2 PgC/year.

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  • IPEN-DOC 26775

    MORAIS, FERNANDO; LANDULFO, EDUARDO ; ARTAXO, PAULO; FRANCO, MARCO A.; SCHAFER, JOEL; HOLBEN, BRENT. Long term characterization of brown carbon in Amazonia using AERONET and in situ measurements. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Optical properties of aerosols in Amazonia have been measured over the last 19 years at several AERONET sites using CIMEL sunphotometers. Ground based measurements of aerosol absorption properties using AE33 Aethalometers were performed in several sites in Amazonia. Measurements were done in Central Amazonia (ATTO tower), as well as in Rio Branco, Cuiabá, Ji-Paraná, and Alta Floresta. The results show an important contribution to absorption by the brown carbon (BrC) component together with black carbon (BC). This behavior can be strongly observed at the wavelengths of 440nm and 470nm, for AERONET and AE33 measurements, respectively. Results from AERONET showed that, in sites dominated by biomass burning such as Alta Floresta, Rio Branco and Ji-Paraná, the BrC was about 20% of BC. In special, for the dry season of 2018 at Rio Branco, the BrC was about 9% of BC, with values of 3.28±3.45 µg m-3 and 0.34±0.58 µg m-3 for BC and BrC, respectively. The measured high variability in the ratio BrC/BC was due to different aging of biomass burning plumes that reached the site, some with high BC values of up to 24 µg m-3. On the other hand, in situ measurements at the ATTO Tower showed that the BrC component can account for 30% of total absorption. For the wet season of 2019, it was observed that BrC accounts for 28 % of BC, with mean values of BC and BrC of 0.23±0.16 µg m-3 and 0.054±0.075 µg m-3, respectively. The high variability in this case was due to plumes of African biomass burning that reached the site in different periods. For central Amazonia, ground based in situ measurements and AERONET agree quite well in the in situ BrC determination, showing a well-mixed atmosphere due to strong convection.

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  • IPEN-DOC 26774

    JEONG, DAUN; SECO, ROGER; EMMONS, LOUISA K.; SCHWANTES, REBECCA; LIU, YINGJUN; MCKINNEY, KARENA A.; MARTIN, SCOT T.; KEUTSCH, FRANK N.; GU, DASA; GUENTHER, ALEX B.; VEGA, OSCAR ; TOTA, JULIO; SOUZA, RODRIGO A.F. de; SPRINGSTON, STEPHEN R.; WATSON, THOMAS B.; KIM, SAEWUNG. Reconciling measured OH through box model simulations during GoAmazon2014/5. In: AGU FALL MEETING, December 9-13, 2019, San Francisco, CA, USA. Abstract... Washington, DC, USA: American Geophysical Union, 2019.

    Abstract: Hydroxyl radicals (OH) are important oxidants in the troposphere, controlling the lifetime of trace gases including methane, which is a greenhouse gas. The primary production of OH is from the photolysis of O3. OH levels can be further sustained through HOx-NOx recycling reactions. Volatile organic compounds (VOC) react with OH to produce organic peroxyl radicals (RO2), which can oxidize NO to NO2, leading to O3 production and subsequent re-generation of OH. However, in low NOx and high VOC environments, OH levels can be limited due to the production of stable peroxides from reactions between peroxy radicals. Therefore, conventional chemistry predict constrained OH levels in remote forest regions. Observations of OH carried out in forests, however, have consistently reported up to 10-fold higher than expected OH levels. In this study, we report OH observations by chemical ionization mass spectrometry (CIMS) conducted in a rainforest environment during the GoAmazon2014/5 campaign. The measurements used in this study, were during the wet season (IOP1), at the T3 site, which was ~ 60 km west of Manaus, Brazil. OH observations are compared to observation constrained box model simulations embedded with a near-explicit chemistry like MCM 3.3.1 (Master Chemical Mechanisms) and condensed mechanisms like RCIM (Reduced Caltech Isoprene Mechanism), CB05 (Carbon Bond Mechanism), CB6r2 (Carbon Bond 6 Mechanism), RACM2 (Regional Atmospheric Chemistry Mechanism), and MOZART_T1 (Model for Ozone and Related Chemical Tracers) that are used in global models.

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  • IPEN-DOC 26773

    CORREA, E.L. ; PEREIRA, L.F. ; FERREIRA, W.L. ; BOSCH-SANTOS, B. ; SCALISE, L. ; GONÇALVES, V. ; SANTOS, R. dos ; SCHELL, J.; CARBONARI, A.W. . Study of the local magnetics and electrics properties at Gd2Ti2O7 by PAC spectroscopy and ab initio calculations. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 760-760.

    Abstract: Gd2Ti2O7 exhibits a complex magnetic behavior with a geometrically frustrated antiferromagnetic ordering below TN = 1.1 K and a second magnetic transition at 0.7 K. In the work here reported, perturbed angular correlation (PAC) technique was used in order to measure electric quadrupole hyperfine interactions at 111mCd probe nuclei on Ti sites. These experimental results along with those for magnetic hyperfine interactions at 155Gd previously reported from Mossbauer Effect spectroscopy were interpreted with electronic structure first-principles calculation. Single and doped-Cd cell simulations have been performed with potential linearized augmented plane waves methods and generalized gradient approximation from Perdew-Burke-Ernzerhorf embodied within the WIEN2k all-electron code. PAC measurements have exhibited 111mCd probes occupying two fraction sites characterized by well-defined quadrupole frequencies (as shown in the spin-rotation spectra in the figure) with almost the same values for the corresponding electric field gradient (efg), however, with slightly difference in the asymmetry parameters. Theoretical efg’s obtained for Cadmium atoms located at Gd or Ti sites of the pyrochlore structure indicate that both experimental hyperfine parameters corresponding to Cd at Titanium site.

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  • IPEN-DOC 26772

    BOSCH-SANTOS, B. ; NASCIMENTO, N. ; SAIKI, M. ; CORREA, E.L. ; SALES, T.S. ; PEREIRA, L.F. ; CABRERA-PASCA, G.A.; CARBONARI, A.W. . Magnetic field at Ce impurities in La sites of LaBaMn2O6 double perovskites. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 759-760.

    Abstract: Magnetic behavior in LaBaMn2O6 double perovskite compounds has been investigated with various techniques, due to the rich variety of electromagnetic properties, such as a colossal magnetoresistance, charge and orbital ordering, and metal-insulator transition. In this paper, we have used a nuclear and short-range technique, the Perturbed Angular Correlation (PAC) spectroscopy, to investigate the magnetic hyperfine field at the 140Ce nucleus of Ce impurities occupying La sites. The radioactive 140La nuclei with a half-life of 40.8 h were produced by direct activation of natural La present in the samples through the irradiation with neutrons in the IEA-R1 nuclear research reactor of IPEN. The PAC measurements were carried out with a six BaF2 detector spectrometer at several temperatures between 10 K and 400 K. This double perovskite samples were synthesized by sol-gel route. The crystal structure was determined by X-ray diffraction and the analyses showed that this method produced perovskite oxides with cubic structure in Pm-3m space group. This phase occurs due to an oxygen deficiency. The local properties investigated by PAC spectroscopy revealed a ferromagnetic transition temperature above 300 K and an anomalous behavior of the temperature dependence of magnetic hyperfine field at La sites, which can be ascribed to the contribution of 4f band of Ce to Bhf at low temperatures due to the increase in its localized character.

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  • IPEN-DOC 26771

    PEREIRA, L.F. ; CARBONARI, A.W. . Local magnetic interactions in Cadmium-doped Cobalt allotropic phases by first principles calculation. In: JOINT MMM-INTERMAG CONFERENCE, January 14-18, 2019, Washington, DC, USA. Abstract... Melville, NY, USA; Piscataway, NJ, USA: AIP Publishing; IEEE Magnetics, 2019. p. 600-600.

    Abstract: Cobalt is one of the most attractive ferromagnetic material at room temperature. While Co is used in industrial processes of catalysis, in fundamental science, the connection between the different crystal structure with magnetic properties of Co has attained the attention. Co can crystallize in four different structures: hexagonal closed-packed (hcp, alpha), face-centered cubic (fcc, beta), primitive cubic (epsilon), and body-centered cubic (bcc). The hcp and fcc phases are stable in bulk and nanostructured samples and the difference in their formation energy is small so that, even under small variations of temperature and/or pressure conditions, hcp and fcc can interexchange easily. Often, the literature reports the co-existence of both structures. In last years, new routes of the synthesis and improvement in previous methods have allowed the production of nanostructured Cobalt samples with Epsilon and bcc crystalline phases, which under usual conditions are metastable. The magnetic properties vary with the structure differences in their electronic structure, e.g. the hcp phase has higher coercivity, whereas the fcc is a soft magnet In the work here reported, first-principles calculations were performed in the four Co structures in order to investigate one sensitive and quite local parameter: the magnetic hyperfine field (mhf). We have used Augmented Planes Waves plus local orbitals (APW+lo) all-electron method based on the density functional theory and implemented in the WIEN2k code to simulate supercells of Co doped with Cd. The resulting mhf at Cd ions is compared with values from perturbed angular correlation spectroscopy measurements using 111Cd as probe nuclei found in the literature for hcp, fcc, and bcc phases. Up to date, experimental results for mhf at 111Cd for epsilon structure are not available. Calculated mhf and magnetic moments agree well with reported experimental values - tab. 1. From the calculated density of states for each structure, it is possible to investigate the differences in the magnetic exchange interaction at an atomic view

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  • IPEN-DOC 26544

    AMARAL, MARCELLO M.; PRETTO, LUCAS de ; RAELE, MARCUS P. . Optical evaluation of polymer deposition for 3D printing. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo, SP: Sociedade Brasileira de Física, 2019.

    Abstract: 3D printing is a technology that is revolutionizing the productive sector [1]. It allows the production of free- form components and systems. It may ¯nd application from biomedical to aerospace engineering, as well as in the production of unique and speci¯c components needed in basic science laboratories. One of the most common approaches for 3D printing is the fused deposition modeling were a plastic ¯lament is fused and the component shape is modeled by layers deposition [2]. The success in the manufacture of the component is related to the addition between successive deposited layers. Increasing the temperature of the ¯lament to ensure perfect adhesion may compromise the desired shape and function characteristics for the component. Scanning Electronic Microscopy (SEM) is the gold standard technique to ensure the ideal condition for the 3D printing and evaluate the bonding between successive layers [2]. However, in this context, SEM is a destructive technique and do not allow real time application. Low Coherence Interferometry (LCI) is an optical technique capable to performing non-destructive tomography evaluation of scatter medium [3]. Using a Michelson interferometer to measure the backscattered light intensity as a function of depth position associated to a lateral scanning it is possible to obtain a cross-section image of the sample [3]. It is non-invasive, relatively inexpensive technique and could allow real time application during manufacturing. The aim of this work was to investigate the use of low coherence interferometry to evaluate the adhesion of successive layers on 3D printed plastic material. A set of samples were manufactured using a 3D printing (Cliever CL1, Brazil), with layer thickness from 100¡250¹m using PLA ¯lament. The sample were evaluated using a SEM and a commercial LCI (OCP930SR - Thorlabs Inc.) and the images were compared. It was possible to observe a correlation on the observed fused ¯laments between the images acquired by SEM and LCI proving that it is possible to use the optical technique as a alternative for 3D printing quality evaluation.

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  • IPEN-DOC 26552

    BENTO, RODRIGO T. ; SILVA FILHO, JORGE C. ; CORREA, OLANDIR V. ; TAKIISHI, HIDETOSHI ; PILLIS, MARINA F. . Synthesis and characterization of reduced graphene oxide-modified anatase TiO2 photocatalysts grown by MOCVD. In: E-MRS SPRING MEETING; IUMRS-ICAM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, May 27-31, 2019, Nice, France. Abstract... 2019.

    Abstract: Inadequate disposal of industrial waste, such as textile dyes and emerging contaminants, have been caused several environmental hazards. Titanium dioxide (TiO2) photocatalysis is an efficient green method for water treatment by solar energy. However, due to its large band gap of 3.2 eV, TiO2 absorbs mostly the UV radiation, which represents only 5-8% of the sunlight spectrum. Recent studies indicate that the surface modification of TiO2 results in an increase in photocatalytic efficiency. In this way, the present paper aims to evaluate the effects of TiO2 surface modification by reduced graphene oxide (rGO). The 470 nm thick anatase-TiO2 films were grown by MOCVD process in a conventional horizontal homemade reactor, on borosilicate substrates at 400 °C. The TiO2 films obtained were dipped into an alkoxide solution including 0.5, 1.5 and 3.0 mg of rGO and 30 mL isopropanol, ultrasonic-treated at room temperature for 40 min, and then dried in an oven at 100 and 150 °C for 24 h. The photocatalytic activity of rGO-TiO2 composites were evaluated by the methylene blue degradation under UV and visible light. The chemical, structural and morphological properties were also characterized. It was observed the presence of rGO agglomerates completely adhered to TiO2 surface. The diffraction peaks identified correspond to anatase phase. Peaks of graphene were also found. The results suggest that the rGO-TiO2 composites have a great potential to be used in water treatment under sunlight.

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  • IPEN-DOC 26538

    OLIVEIRA, EDUARDO C. de ; BENTO, RODRIGO T. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. . Performance of nitrogen-doped TiO2 films grown by MOCVD for water treatment under visible light. In: E-MRS SPRING MEETING; IUMRS-ICAM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS, May 27-31, 2019, Nice, France. Abstract... 2019.

    Abstract: Titanium dioxide is a semiconductor employed as catalyst in the photodegradation of organic pollutants and bacteria. However, due to its large band gap TiO2 only can be excited by UV light. Recently, TiO2 doping with metals or nonmetals elements has been extensively exploited to allow its use under visible light. In the present work, nitrogen-doped and undoped TiO2 films were grown on borosilicate substrates at 400 ° C for 60 minutes by metallorganic chemical vapor deposition (MOCVD). Titanium isopropoxide IV was used as precursor of titanium and oxygen, and ammonia as nitrogen source. Ammonia was incorporated into the films in three different quantities during the growth. The effect of nitrogen contents on the structural and surface properties of TiO2 catalysts was evaluated. Both doped and undoped films presented rounded well-defined anatase grains. XPS analyses revealed that values of 1.6; 2.4 and 7.3 at% of nitrogen were incorporated into the films by varying the ammonia flux during the growth. Degradation assays have shown that nitrogen-doped TiO2 films exhibited high photocatalytic activity under visible light irradiation. Undoped films did not present activity in this condition. The better catalytic performance under visible light, 55% of dye degradation, was attributed to the film containing 2.4 at% of nitrogen. The results suggest that nitrogen-doped TiO2 catalysts grown by MOCVD have great potential to be used in the treatment of water under sunlight.

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  • IPEN-DOC 26765

    SUZUKI, M.F. ; ALMEIDA, L.A. ; POMIN, S.A. ; SILVA, F.D. ; FREIRE, R.P. ; OLIVEIRA, J.E. ; AFFONSO, R. ; BARTOLINI, P. ; SOARES, C.R.J. . Expression of the human prolactin antagonist delta 1-11 G129R-PRL in E. coli periplasm. In: SANTOS, NATHALIA V. dos (Ed.) BIOPARTITIONING & PURIFICATION CONFERENCE, November 11-13, 2019, Guarujá, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Microbiologia, 2019. p. 110-110.

    Abstract: Recombinant human prolactin antagonist delta 1-11 G129R-hPRL is a 21.9 kDa protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining an authentic, soluble, and correctly folded protein, as an alternative to the cytoplasmic production in inclusion bodies of an unfolded, insoluble protein, carrying an extra initial methionine. The aim of this work was to carry out the expression of delta 1-11 G129R-hPRL antagonist in the periplasm of E. coli, testing different temperatures. E. coli BL21(DE) strain, transformed with a plasmid based on a pET25b(+) vector, DsbA signal peptide and delta 1-11 G129R-hPRL cDNA, was cultured in LB medium with ampicillin addition. After overnight culture at 30 °C, 0.6 mM IPTG was added and five different temperatures were applied: 25, 30, 32, 35 and 37 °C. Periplasmic fluid was extracted after 5 hours by osmotic shock. The samples were analyzed by SDS-PAGE, Western blotting and RP-HPLC. The best condition was increasing the temperature to 35 °C for 5 h, after having reached the late log phase. The specific expression of 0.14 ± 0.02 μg/mL/A600, with a final optical density of 3.43 ± 0.13 A600 (n = 3) was obtained. Purification by nickel affinity chromatography (Hisprep FF) with Imidazole elution followed by size exclusion chromatography (Sephacryl S-100) was carried out connected to an ÄKTA purification system. Quantification was carried out by comparison between the areas under the curve observed in the HPSEC chromatogram, for the unknown samples versus the Internal Standard of rec-hPRL. The final product showed >95% purity by HPSEC analysis. The delta 1-11 G129R-hPRL antagonist was expressed and purified for further in vivo and in vitro tests, in view of clinical applications for inhibiting cancer cell proliferation that overexpresses prolactin receptor and studies related to prolactin function in anterior pituitary.

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  • IPEN-DOC 26764

    FERREIRA, MERILYN S. ; PASK, HELEN M.; WETTER, NIKLAUS U. . Yellow laser at 573 nm generated by intracavity SHG diodeside-pumped Raman laser. In: ADVANCED SOLID STATE LASERS, September 29 - October 3, 2019, Vienna, Austria. Resumo expandido... Washington, DC, USA: OSA, 2019. (Laser Congress 2019 (ASSL, LAC, LS&C)).

    Abstract: A diode side-pumped Nd:YLiF4 crystal for fundamental wavelength generation and intracavity Stokes conversion in KGW are employed to obtained 6.1W maximum output power, 11.9% slope efficiency and 11.8% diode-to-yellow conversion efficiency at 573 nm.

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  • IPEN-DOC 26763

    PETRI, ANNA R.; MALAFRONTE, ALEXANDRE A.; GONCALVES, JOSEMARY A.C. ; BARROS, SUELEN F.; BUENO, CARMEN C. ; MAIDANA, NORA L.; MANGIAROTTI, ALESSIO; MARTINS, MARCOS N.; VANIN, VITO R.. Study of the response of a commercial photodiode for photons and electrons with energies between 10 and 100 keV. In: IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE; INTERNATIONAL SYMPOSIUM ON ROOM-TEMPERATURE X-RAY AND GAMMA-RAY DETECTORS, 26th, October 26 - November 2, 2019, Manchester, UK. Abstract... Piscataway, NJ, USA: IEEE Nuclear and Plasma Sciences Society, 2019. p. 129-129.

    Abstract: In this work, a commercial low-cost silicon PIN (p type-Intrinsic-n type) photodiode model BPX 65 is characterized with respect to reverse current and capacitance of the junction. The measurements indicate that the photodiode is fully depleted for a reverse bias greater than 17 V and the width of the depletion zone is estimated to be 60 (3) μm. The device has been applied for gamma spectrometry, showing a resolution around 2.4 keV (FWHM - Full Width at Half Maximum) for photons with energies between 14 and 136 keV. This is the same resolution obtained with a pulser, 2.39 (2) keV, indicating that the main limitation of the spectroscopy system employed is electronic noise. As this is a promising detector not only for low-energy photons, but also for charged particles, the response of the BPX 65 has been investigated with a low-dispersion electron beam with energies between 20 and 100 keV. Under such conditions, the response function cannot be described as a simple Gaussian distribution. Moreover, the analytical response functions for electrons presented in the literature need to be generalized including a polynomial term. The proposed response function was tested and the behavior of the free parameters with the energy of the impinging electron is shown to be smooth. Thus, it is possible to extract from the data a well behaved parametrization.

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  • IPEN-DOC 26560

    CABRAL, FERNANDA V. ; RIBEIRO, MARTHA S. . Methylene blue-mediated photodynamic therapy on cutaneous leishmaniasis: an in vitro and in vivo study. In: INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... 2019.

    Abstract: Cutaneous leishmaniasis (CL) is a neglected disease, which promotes destructive lesions. Difficulties in treatment are related to resistance and toxicity. Methylene blue-mediated photodynamic therapy (MB-PDT) has emerged as a promising treatment considering low cost and no reports about resistance. We evaluated MB-PDT on Leishmania amazonensis in vitro and in vivo using a red LED at different fluences. Our results demonstrated that the best fluence in vitro was not effective in vivo, and a higher dose was necessary to provide better responses in mice. This study reinforces the idea that a well-planned protocol is necessary for a successful MB-PDT on CL.

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  • IPEN-DOC 26559

    SABINO, CAETANO P.; BAPTISTA, MAURICIO S.; RIBEIRO, MARTHA S. ; LINCOPAN, NILTON. The mechanisms of bacterial inactivation via MB-APDT avoid drug resistance. In: HASAN, TAYYABA (Ed.) INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... Bellingham, WA, USA: SPIE, 2019. (Proceedings SPIE 11070).

    Abstract: Antimicrobial photodynamic therapy (APDT) is trending as a powerful therapeutic platform to minimize the negative impacts of microbial drug resistance. The mechanisms of action of APDT are imposed as a generalized oxidation of all cellular structures. Therefore, is assumed that the development of resistance to APDT is very unlikely to occur due to its multitarget oxidative effects. Even though the instant effects of APDT may be interesting to several situations, the few microbial cells left alive after irradiation procedure may be enough to allow tissue recolonization. Therefore, to ensure higher effectiveness of APDT protocols should also rely on therapeutic combinations with longer lasting effects. In this study, we report the statistical correlation of bacterial inactivation rate with the degradation rate of lipids, proteins and DNA. We observed that APDT mediated by methylene blue (MB) and red light can induce degradation of enzymes associated with drug resistance. Thus, cells exposed to sublethal doses of MB-APDT may recover sensitivity to antibiotics they were previously resistant. This fact may lead to a time interval where highly resistant pathogens become sensitive to most standard drugs, such as penicillin. Additionally, we observed that drug-resistance genes present in bacterial DNA are severely damaged. Hence, drug resistance gene expression and/or dissemination to other cells should also be impaired. In summary, we can conclude that APDT also challenges drug resistance by degradation of related enzymes and DNA.

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  • IPEN-DOC 26558

    GARCEZ, AGUINALDO S.; NARDINI, ELISA F.; CARDOSO, RIELSON; RIBEIRO, MARTHA S. . The potential of phytotherapeutic compounds available on the market as a new photosensitizers for dental antimicrobial PDT: a photochemical and photobiological in vitro study. In: HASAN, TAYYABA (Ed.) INTERNATIONAL PHOTODYNAMIC ASSOCIATION WORLD CONGRESS, 17th, June 28 - July 4, 2019, Cambridge, Massachusetts, USA. Abstract... Bellingham, WA, USA: SPIE, 2019. (Proceedings SPIE 11070).

    Abstract: This study evaluated Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum available on the market as photosensitizers (FS) in Antimicrobial Photodynamic Therapy (aPDT). Each FS were analyzed in a spectrophotometer between 350 and 750 nm, to determine the ideal light source. Once the absorption bands were determined, 3 light sources were selected to determine the concentration of use, the compounds were verified at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, FS were evaluated for cytotoxicity on fibroblast culture. Each compound was then irradiated with each light source and evaluated for indirect reactive oxygen species (ROS) production. The bacterial reduction was tested in culture of E. faecalis in planktonic form and in biofilm using energy of 10 J and Energy Density of 26 J/cm2. The tested compounds had light absorption in three bands of the visible spectrum: violet (405 nm), blue (470 nm) and red (660 nm). At 1:6 concentration, none of the compounds promoted tooth staining, as none of the compounds showed significant toxicity in cells or bacterial suspension. In addition, when the compounds were irradiated at each wavelength, significant ROS production was observed. When the aPDT was performed on the planktonic and biofilm bacteria, significant microbial reduction was observed for both cases, reaching up to 5Logs of reduction. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum, showed potential for use in aPDT as photosensitizing agents.

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  • IPEN-DOC 26751

    ORTIZ, N. ; MAICHIN, F. ; MACEDO, M.V. . Using microstructured yeast as biotemplate for TiO2 deposition applied on amoxicillin solar photodecomposition. In: IWA INTERNATIONAL CONFERENCE ON WATER RECLAMATION AND REUSE, 12th, June 16-20, 2019, Berlin, Germany. Resumo expandido... 2019.

    Abstract: The indication of amoxicillin (AMOX) is the most frequent by the public health assistance in Brazil. After the body metabolization, the antibiotic is discharged by excretes in the sewage system; also acting as secondary pollution sources for surface water resources. The microstructured yeast culture (biotemplate) enhances the TiO2 surface area before the amoxicillin solar photodecomposition. The maximum removal percentage was 56% of AMOX with pseudo-second-order kinetics. The use of the low-frequency ultrasonic source in the TiO2 slurry dispersion after the yeast culture enhanced the TiO2 surface area and its effectiveness during the antibiotics solar photodecomposition.

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  • IPEN-DOC 26750

    ORTIZ, N. ; NICOLAU, T.S. ; SOUZA, J.P. ; SILVA, A.. Ultrasonic TiO2 solar photodecomposition and biocarbon sorption processes to remove amoxicillin and cephalexin from binary systems. In: IWA INTERNATIONAL CONFERENCE ON WATER RECLAMATION AND REUSE, 12th, June 16-20, 2019, Berlin, Germany. Resumo expandido... 2019.

    Abstract: The cephalexin (CEPH) and amoxicillin (AMOX) antibiotics are the most indicated in the medical prescriptions in Brazil, as the antibiotics used for public health assistance and also for veterinary medicine. Nowadays Brazil is a higher protein animal producer in the world. After the metabolization, the antibiotics discharge in the sewage system and manure composition on rural areas; act as secondary pollution sources for surface water resources. The integrated processes applying the ultrasonic source before the solar photodecomposition and biosorption showed the maximum removal percentage of 91.47% for AMOX and 90.62% for CEPH. Considering the binary systems with the 17:83 proportion percentages of AMOX and CEPH the removal percentage was 89.15% and 97.90% respectively. The use of low-frequency ultrasonic waves before the solar photodecomposition increased the TiO2 surface area and effectiveness and enhanced the removal efficiency for both cephalexin and amoxicillin alone and in binary mixtures.

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  • IPEN-DOC 26553

    KODAMA, YASKO ; RODRIGUES JUNIOR, ORLANDO ; GARCIA, RAFAEL H.L. ; OTUBO, LARISSA ; SANTOS, PAULO S. ; VASQUEZ, PABLO A.S. . Kinetics of Free Radicals Decay Reactions in Cellulosic Based Heritage Materials Disinfected by Gamma Radiation. In: VASQUEZ, PABLO A.S. (Ed.); NAGAI, MARIA L.E. (Coord.) INTERNATIONAL SYMPOSIUM ON GAMMA IONIZATION: TECHNOLOGY FOR PRESERVATION OF CULTURAL HERITAGE, 1st, October 25, 2019, São Paulo, SP. Abstract... São Paulo, 2019.

    Abstract: In this study, contemporary paper samples were irradiated using gamma radiation from Co-60 with different absorbed doses. The absorbed dose range was chosen taking into account the effective values to promote insect eradication, fungal disinfection and sterilization. The kinetics of decay of the cellulose free radicals induced by irradiation was analyzed using Electron Paramagnetic Resonance. Several spectra were obtained at room temperature for each applied absorbed dose immediately after irradiation as reference measurements. In order to understand the decay process of free radicals, additional spectra were obtained for different decay times up to almost 50 days after irradiation. De-noising treatment of the original obtained spectra signals were performed using wavelets. By integrating the electron paramagnetic resonance curves were calculated the area values and correlated to concentration, it is equivalent to spin concentration. Comparison of spectra was done by normalization of calculated area corresponding to cellulose spin concentration, considering the first measurement after irradiation as 100%. Further analyses and calculations were made to study the half-life and the kinetics models of the free radicals created. X-ray diffraction was carried out to identify crystalline phases and the effect of ionizing radiation on the crystalline structure of cellulose in paper. Scanning electron microscopy and Scanning Electron Microscopy Energy Dispersive Spectrometry were performed to analyze structure modifications by ionizing radiation, identifying cellulose fiber agglomeration zones and to quantify chemical elements. Likewise, samples were analyzed by infrared spectroscopy to determinate changes on the carbonyl groups. Results shown that for sterilization dose, 80% of the cellulose free radicals induced by ionizing radiation disappear in almost 40 days and for disinfection dose in 8 days. It can be concluded that if no significant modifications (side-effects) appear in the irradiated material after the radical decay time, the material will stay stable for the remaining lifetime. Proposed method using electron paramagnetic resonance results showed suitably to study the behavior of radicals on cellulosic based cultural heritage materials.

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  • IPEN-DOC 26724

    FERREIRA, G.V.R.; MASTRO, N.L.D. . Importância de mucilagens em nutrição. In: OLIVEIRA, JOÃO R.M. (Ed.) ENCONTRO DE INICIAÇÃO CIENTÍFICA, 16th, 23 de novembro, 2019, São Paulo, SP. Resumo... São Paulo, SP: Universidade Nove de Julho, 2019. p. 196-196.

    Abstract: A ciência aplicada às áreas de saúde, tecnologia de alimentos e biotecnologia tem buscado formas de obter materiais menos prejudiciais aos organismos e que tragam algum benefício funcional, os pesquisadores buscam sempre inovar a forma de produzir produtos e incluir coisas naturais em suas mercadorias (UTPOTT, 2012). A mucilagem, no sentido botânico é uma secreção rica em polissacarídeos hidrocolóides. É uma substância vegetal, viscosa que aumenta de volume sob a ação da água, ficando com consistência gomosa com consequentes propriedades adesivas e espessantes. As mucilagens são utilizadas como reguladoras do trânsito intestinal, como emolientes e como veículo de misturas com substâncias sólidas. Retém a água aumentando de volume. Encontra-se, em alta concentração, em raízes aquáticas para sua proteção, envolvendo algumas sementes etc. No sentido farmacológico, é uma substância viscosa resultante da solução de determinadas matérias em água. Grande grupo de polissacarídeos complexos, frequentemente presentes nas paredes celulares das plantas aquáticas e nos tegumentos de algumas outras espécies. Mucilagem é rígida quando seca e pegajosa quando húmida. Tem possivelmente uma função protetora e de âncora nas plantas. (Hine, 2005) O objetivo deste trabalho é definir e apresentar as características que as mucilagens possuem, suas aplicações, propriedades reológicas, tecnológicas e funcionais e onde elas podem ser encontradas. O método de elaboração foi por meio de revisão bibliográfica. Trabalhos com a mucilagem mostraram-se interessante na área de nutrição, como por exemplo, na substituição do glúten em pães e bolos realizados por Zambrano et al. (2017) com psyllium. Vantagem essa, que dá a possibilidade de pacientes com doença celíaca usufruirem de massas que antes contavam com glúten e os restringiam. A mucilagem pode contornar isto, pois suas características reológicas de viscosidade e extensibilidade fizeram o papel do glúten. Pode-se concluir que a mucilagem no sentido nutricional e funcional se tornou uma ferramenta excelente em preparações, ainda mais para pessoas que possuem restrições ao glúten. Em alguns artigos, é possível destacar a prevenção do cancêr de cólon relacionado com a mucilagem. As fibras mucilaginosas mais utilizadas para sua extração são as de Linhaça, Chia, Inhame e psyllium. Ainda há muito o que explorar nesta área, e os resultados realizados nos trabalhos são promissores e abrem margem para novas modalidades de utilização da mesma.

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  • IPEN-DOC 26531

    ROVANI, SUZIMARA ; FUNGARO, DENISE ; CARVALHO, FELIPE ; SANTOS, JONNATAN. Comparative study of methods for the synthesis of silica nanoparticles from sugarcane waste ash. In: ACS NATIONAL MEETING & EXPOSITION, 257th, March 31 - April 4, 2019, Orlando, FL, USA. Abstract... Washington, DC, USA: American Chemical Society, 2019.

    Abstract: Adding value to agro-industrial solid waste is a challenge for sustainable and green chemistry. Brazil is the worlds largest producer of sugarcane, producing about 633 million tons per year, and generates huge amounts of sugarcane waste ash (SWA) which is a rich source of silica. Therefore, the development of a process related to the use of this raw material rich in Si for the production of silica nanoparticles (SiNPs) is fundamental. SiNPs are presently applied in paints, biopolymers, catalysts, adsorbents, among others [1]. In this study, SiNPs were produced from SWA by different routes and yield and purity of products obtained were evaluated. The synthesis of SiNPs was carried out by the two-step method. First, NaOH was mixed with SWA, and the resultant mixture was fused at 350 C for 30 min or 1 h, varying the ash:NaOH ratio (1:1.5 or 1:2). After, was added distilled water in the funded solid and refluxed for 1 h to leave all the sodium silicate dissolved in the aqueous medium [2]. Then, HCl or H2SO4 6.0 mol L-1 was added, dropwise, until pH decrease to 2.0. The yield of SiNPs extraction was around 67 % for samples obtained with ash:NaOH ratio 1:1.5, 30 min or 1 h of muffle and HCl solution. So, fusion time was not significant for the yield of the synthesis. Subsequent experiments were conducted at 30 min, ash:NaOH (1:2) and HCl or H2SO4 (Table 1). The yield of silica nanoparticles extraction was 93 % and 67 % with HCl and H2SO4, respectively. The silica obtained with H2SO4 showed lower yield, but higher purity, when compared to the silica obtained with HCl. The yield of silica extraction was higher with ash:NaOH ratio 1:2 and with the HCl. However, the highest purity was obtained with H2SO4.

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  • IPEN-DOC 26551

    NAGAI, MARIA L.E.; SANTOS, PAULO S. ; OTUBO, LARISSA ; OLIVEIRA, MARIA J.A. de ; VASQUEZ, PABLO A.S. . Ionizing radiation for the preservation and conservation of photographic and cinematographic films. In: VASQUEZ, PABLO A.S. (Ed.); NAGAI, MARIA L.E. (Coord.) INTERNATIONAL SYMPOSIUM ON GAMMA IONIZATION: TECHNOLOGY FOR PRESERVATION OF CULTURAL HERITAGE, 1st, October 25, 2019, São Paulo, SP. Abstract... São Paulo, 2019.

    Abstract: The Nuclear and Energy research Institute – IPEN-CNEN/SP through the Multipurpose Gamma Irradiation Facility has treated several bibliographical collections of Sao Paulo University-USP for disinfestation and disinfection of contaminated materials with insects and fungi. In this sense, gamma radiation from cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because the biocidal action. Disinfection using gamma radiation for cultural heritage materials has been widely applied around the world in the last decades. Adequate storage of photographic and cinematographic materials is a challenge for conservation experts from preservation institutions. Contamination by fungi is one of leading causes of problem in this kind of collections. In addition, another common physicochemical degradation affecting cellulose triacetate films causing deacetylation of polymer chain is called “vinegar syndrome”. In this work are presented results of effect of ionizing radiation on photographic and cinematographic films. Selected films were characterized by FTIR-ATR spectroscopy and FEGSEM-EDS microscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 200 kGy. Irradiated samples were analyzed by UV-vis spectrophotometry, FEGSEM, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Results showed that disinfection by gamma rays can be achieved safely applying radiation absorbed doses between 6 kGy and 10 kGy with no change or modification of main properties of the constitutive polymeric materials. Gamma rays due to the effect of crosslinking is presented as an alternative to treat films affected by “vinegar syndrome” applying absorbed dose of 50 kGy in order to increase shelf life of cultural heritage materials.

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  • IPEN-DOC 26550

    LIMA, LENI M.P.R. ; KODAMA, YASKO ; OTUBO, LARISSA ; SANTOS, PAULO S. ; VASQUEZ, PABLO A.S. . Effect of ionizing radiation on the color of botanical collections: exsiccata. In: VASQUEZ, PABLO A.S. (Ed.); NAGAI, MARIA L.E. (Coord.) INTERNATIONAL SYMPOSIUM ON GAMMA IONIZATION: TECHNOLOGY FOR PRESERVATION OF CULTURAL HERITAGE, 1st, October 25, 2019, São Paulo, SP. Abstract... São Paulo, 2019.

    Abstract: Conservation and preservation methods are essential to maintain the wholeness of botanical collections specially for dried herbarium specimens also known as exsiccates, usually referring to a set of identified specimens belonging to taxa and distributed among all herbaria around the world. These vegetal materials are subjected to fungal attack and insect pests threatening their entirety. In recent years, disinfection by ionizing radiation has become an effective strategy to preserve cultural heritage objects and archived materials with excellent results. In this work, the effects on color properties of exsiccates samples irradiated with gamma radiation from Co-60 with different absorbed doses were studied. The botanical pressed and dehydrated samples – exsiccates – were selected from the Dom Bento José Pickel Herbarium (SPSF), located at São Paulo (Brazil). Two exsiccate samples were selected: SPSF-4021 and SPSF-08821. These samples come from Asteraceae and Solanaceae family and were collected in 1946 and 1984, respectively. Families of selected botanical collections are very susceptible to biodegradation. The irradiation was performed at the Multipurpose Gamma Irradiation Facility at IPEN applying absorbed doses of 1 kGy, 6 kGy and 10 kGy. The selected ranged dose promotes insect disinfestation and fungal disinfection. Results were analyzed using colorimetry with CIELAB color space scale. Scanning electron microscopy were performed to analyze surface topography and elemental structure modifications by ionizing radiation and characterize the non-irradiated (0 kGy) and the effective disinfected (10 kGy) exsiccata samples. The results revealed no significant changes on colorimetric morphological properties of then irradiated samples. The color changes between the non-irradiated samples and the irradiated sample at the high absorbed dose are perceptible, but acceptable considering the adopted scale. The microscopy images of the non-irradiated and 10 kGy irradiated samples did not show significant differences in the topographic morphology of the exsiccata samples. The results obtained corroborate the studies of the application of gamma radiation to preserve materials of cellulosic origin. Subsequently and for continuity of this research, other samples will be analyzed.

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  • IPEN-DOC 26542

    VIEIRA, ANA C.D.; KODAMA, YASKO ; OTUBO, LARISSA ; SANTOS, PAULO S. ; VASQUEZ, PABLO A.S. . Effect of ionizing radiation on the color of featherwork. In: VASQUEZ, PABLO A.S. (Ed.); NAGAI, MARIA L.E. (Coord.) INTERNATIONAL SYMPOSIUM ON GAMMA IONIZATION: TECHNOLOGY FOR PRESERVATION OF CULTURAL HERITAGE, 1st, October 25, 2019, São Paulo, SP. Abstract... São Paulo, 2019.

    Abstract: Featherwork collections are usually stored and managed by ethnographic museums. Even though the featherwork manufacturing is still practiced by the indigenous communities, the offer of raw material and the contact with the surrounding society ended up reducing the production scale of such objects. Consequently, the preservation of the culture heritage is very important, particularly in museums. Biodegradation can affect featherworks mainly by xylophagous insects and moths’ action. The tropical Brazilian weather contributes to the contamination and proliferation of insects and fungi making the preservation conditions difficult. The use of gamma radiation for the disinfection of cultural heritage objects and archived materials has shown to be a safe process and an excellent alternative to traditional methods usually involving high persistent and toxic chemical pesticides. In this work are presented the preliminary results of the ionizing radiation effects on the color and morphological properties of a featherwork from the Museum of Archeology and Ethnology of the University of São Paulo (MAE/USP). Samples of feathers were selected from the artifact and irradiated with gamma rays at the Multipurpose Gamma Irradiation Facility at IPEN, applying absorbed doses between 0.5 kGy to 200 kGy. Samples were firstly chosen according to feather colors, photographed and analyzed using colorimetry with CIELAB 1976 color space scale and scanning electron microscopy (SEM), just after and 48 hours after the irradiation process. The results shown had no significant changes on color and morphological properties within the disinfection absorbed dose range applied.

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  • IPEN-DOC 26701

    BERUSKI, OTAVIO ; KORKISCHKO, IVAN ; LOPES, THIAGO ; FONSECA, FABIO C. ; PEREZ, JOELMA. A hybrid serpentine-interdigitated flow channel geometry for fuel cells. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: Fuel cells have impressive potential for decarbonization and as high efficiency power sources, however many challenges have yet to be addressed for large scale deployment and uptake. Among the many noteworthy lines of research underway, investigating the best flow field in a given device has been carried a number of times, with perhaps limited success regarding performance improvement. As a possible final attempt to look over such matters individually, from the component point of view, we propose yet another flow channel geometry for small-scale fuel cells, in particular polymer electrolyte fuel cells (PEFCs). The proposed geometry incorporates elements from the two most studied geometries, namely single serpentine and interdigitated. The rationale is that serpentine channels have large pressure drop, thus aiding in water removal, while interdigitated promises to deliver large quantities of reactants to the catalyst. However both seem to fail where the other excels, and thus devices are left to compromises. The new geometry, as well as its inspirations, are simulated in a previously validated computational model, further improved and with high spatial resolution, of a prototype PEFC cathode. The model is isothermic, non-electrochemical and disregards water, as the experimental system. However it has been shown to be useful when studying PEFCs, and a secondary goal of this work is to corroborate this. Comparing simulation results between geometries, it is seen that the hybrid geometry does inherit the characteristics of interest, i.e. high reactant utilization and pressure drop, suggesting it may be of use in real PEFCs. Finally, a niche application is proposed based on the reaction rate distribution of the hybrid geometry.

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  • IPEN-DOC 26700

    LOPES, THIAGO ; BERUSKI, OTAVIO ; KORKISCHKO, IVAN ; MANTHANWAR, AMIT M.; PISTIKOPOULOS, EFSTRATIOS N.; FONSECA, FABIO C. ; MENEGHINI, JULIO R.; KUCERNAK, ANTHONY R.. Unveiling fundamental transport phenomena in fuel cells. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: In situ and ex situ spatially-resolved techniques are employed to investigate reactant distribution and its impacts in a polymer electrolyte fuel cell. Temperature distribution data provides further evidence for secondary flows inferred from reactant imaging data, highlighting the contribution of convection in heat as well as reactant distribution. Water build-up from neutron tomography is linked to component degradation, matching the pattern seen in the reactant distribution and thus suggesting that high, nonuniform local current densities shape degradation patterns in fuel cells. The correlations shown between different techniques confirm the use of the versatile reactant imaging technique, which is used to compare commonly used flow field designs. Among serpentine-type designs, the single serpentine is superior in both equivalent current density and reactant distribution, showing large contributions from convective flow. On the other hand, the interdigitated design is shown to produce larger equivalent current densities, while showing a somewhat poorer reactant distribution. Considering the correlations drawn between the techniques, this suggests that the interdigitated design compromises durability in favour of power output. The results highlight how established techniques provide a robust background for the use of a new and flexible imaging technique toward designing advanced flow fields for practical fuel cell applications.

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  • IPEN-DOC 26699

    NANDENHA, JULIO ; YAMASHITA, JESSICA Y. ; FONTES, ERIC H. ; FONSECA, FABIO C. ; NETO, ALMIR O. . Electrocatalytic oxidation of methane in an acidic electrolyte using PdMn/C-ITO electrocatalysts synthetized by sodium borohydride reduction process. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: Pd/C-ITO and PdMn/C-ITO electrocatalysts with different atomic ratio (90:10, 70:30 and 50:50) were synthetized by borohydride reduction method and characterized by X-ray diffraction, Transmission electronic microscopy and electrochemical studies (cyclic voltammetry). The electrochemical studies showed that PdMn(50:50)/C-ITO had superior performance for electrochemical oxidation of methane in an acidic electrolyte at 25 oC compared to others electrocatalysts prepared. The experiments in a single DMEFC also showed that the PdMn(70:30)/C-ITO electrocatalyst exhibited higher performance for methane oxidation in comparison with Pd/C-ITO, PdMn(90:10)/C-ITO and PdMn(50:50)/C-ITO electrocatalysts. These result indicated that the addition of Mn to Pd favor the electrochemical oxidation of Methane in acid medium, where this effect could be attributed to the synergy between the constituents of the binary electrocatalysts or to electronic modification of Pd atoms by the neighboring Mn atoms as the proximity of Pd and Mn atoms on the surface of the C-ITO (bifunctional mechanism - the presence of Pd and Mn oxides species).

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  • IPEN-DOC 26698

    SANTOS, MONIQUE C.L. ; NUNES, LIVIA C. ; SILVA, LUIS M.G. ; RAMOS, ANDREZZA S. ; FONSECA, FABIO C. ; SOUZA, RODRIGO F.B. de ; NETO, ALMIR O. . Direct Alkaline Anion-Exchange Membrane Fuel Cell to converting methane into methanol. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: Methane is the main constituent of natural gas and can be converted in energy with fuel cell application and higher value-added chemicals cogeneration. In Alkaline Anion-Exchange Membrane Fuel Cell (AAEMFC) is possible led in a way that leads to more oxidized products, therefore more electrons transferred. The investigation was realized for the methane oxidation on Pt/C, Pd/C, Ni/C as catalysts. The electrocatalysts were prepared using a sodium borohydride method with 20 wt% of metals loading on carbon. The X-ray diffraction (XRD) analysis revealed a cubic face-centred structure (CFC) for Pt/C and Pd/C catalysts, was observed Ni/NiO phases for Ni/C electrocatalyst. The Transmission Electron Microscopy (TEM) exhibited a good dispersion of nanoparticles and some agglomerations on the support, with a mean size of 6.4 nm for Pd/C, 5.7 nm for Ni/C and near to 2 nm size for Pt/C. The experiments with AAEMFC showed that all materials can carry out the reaction spontaneously. Pt/C catalyst presents energy density twice times higher than the other materials. FTIR data suggest that methane was converted into small products organic molecules such as methanol and formate in different potentials for Pt/C, Pd/C, and Ni/C.

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  • IPEN-DOC 26697

    LIVINALLI, MARINA M.; RODRIGUES, LAYS N. ; FONSECA, FABIO C. . Reducing the sintering temperature of solid oxide fuel cells by controlling the shape of ceria-based eletrolyte nanoparticles. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: The development of solid oxide fuel cells operating at intermediate temperature (IT-SOFCs) and using carbonaceous fuels to generate power have been crucial for the widespread commercialization of SOFCs. Gadolinium-doped cerium oxide (CGO) is known to display the desired properties to be used both as a high ionic conductor electrolyte at intermediate temperatures and as an active layer in the anode due to its catalytic properties for the decomposition of fuels containing hydrocarbons. In this study IT-SOFCs were fabricated with highly reactive nanorods of CGO electrolyte powder with shape controlled by a hydrothermal synthesis developed in this project. The tested fuel cell system consists of the CGO electrolyte support, lanthanum strontium cobalt ferrite (LSCF) cathode and Ni/CGO anode. The performance of the cell was evaluated with hydrogen as a fuel and air as an oxidant at temperatures between 500–700 °C, further work will be carried out to evaluated the performance of the cell when operating with natural gas. The experimental results indicate that a high-performance IT-SOFC can be obtained with a relatively low temperature (1.150 􀀀C) two-step sintering of the ceriabased layers.

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  • IPEN-DOC 26696

    LANDULFO, EDUARDO ; MACEDO, FERNANDA M. ; CORREA, THAIS ; ARAUJO, ELAINE ; ANDRADE, IZABEL ; ARLEQUES, ANTONIO G. ; MIRANDA, JULIANA T. de M. ; SILVA, JONATAN da ; GUARDANI, ROBERTO. Implementation of CH4 (methane) Raman lidar detection system from anthropic sources. In: ENERGY TRANSITION RESEARCH AND INNOVATION, October 1-2, 2019, São Paulo, SP. Abstract... São Paulo: Research Centre for Gas Innovation, 2019.

    Abstract: Fugitive emissions, defined as unintended or irregular leaks of gases and vapors, are an important source of air pollution that is difficult to monitor and control. Within industrial facilities such as oil and gas processing plants, fugitive methane emissions can be a significant source of greenhouse gas emissions. In Brazil, as in other countries, there are specific regions with high concentration of industrial activities, and showing high population density. These sites, including megacities like São Paulo, are growing in size and economic activity. At the same time, there is a remarkable growth in concerns about the environmental issues associated with these activities. In a constantly changing world, with increasing concentrations of greenhouse gases (GHGs), among them methane (CH4) and volatile organic compounds (VOC), mitigation of atmospheric emission these gases to contain global warming, is of key concern, gas data suggest that fugitive emissions accounted for more than 5% of global greenhouse gas emissions over the past 5 years. Optical remote sensing techniques as lidar can attend the need for real time and trustable information on fugitive emissions. These techniques are non-intrusive, of relative simple construction, thus demanding less maintenance, and are able to provide data from distant locations with a high spatial resolution, typically up to 20 km from the measuring local, and 3 to 4 m long segments. Besides, information on different pollutants can be obtained simultaneously by adequate optical arrangements and data treatment methods. The technique can supply adequate information at lower costs and less effort than other techniques. The Cavity Ringdown Laser Spectroscopy (CRDS) technique was adopted because it is widely used in the detection of gas samples that absorb light at specific wavelengths and also for their ability to detect mole fractions up to the parts per trillion level. The correlation of the data between the techniques of real-time detection becomes interesting, since practical operations, fast and with a high level of sensitivity and precision are made. The mixing ratio of CH4 can be observed within the planetary boundary layer. The measured methane profiles correlate with the acquisitions made with the CRDS, however, an additional contribution of control data in which the Raman lines detect with high sensitivity.

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  • IPEN-DOC 26130

    ISIDORO, ROBERTA A. ; SANTOS, GABRIEL S. dos; FONSECA, FABIO C. . CoNi/C electrocatalysts for alkaline fuel cell. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 228-228.

    Abstract: Solid alkaline fuel cell (SAFC) has been studied as possible alternatives in the production of electricity for portable and stationary applications. The oxygen reduction reaction (ORR) is key electrochemical processes, because his low kinetics decreases system efficiency. The main progresses in the cathodic side have been related to the development and improvement of activity and stability. In this way, non precious material has been studied, in the last years. Cobalt oxides have been reported to exhibit good performance for ORR. However, cobalt bimetallic can be more eficient catalysts for ORR, especially for its bifunctional function. Some Ni-based electrocatalysts have shown relevant good results for ORR in four-electron pathway. Song et al. Showed, for example, that Ni addition into Ag-based electrocatalysts for ORR decreases the ORR overpotential, while an increasing in the limiting current density is observed. In this way, a bimetallic CoNi/ C was produced to be used as a cathode in alkaline fuel cell.

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  • IPEN-DOC 26129

    QUEIROZ, FERNANDA M.; ARAUJO, JOAO V.S. ; TERADA, MAYSA; LAMAKA, SVIATLANA; COSTA, ISOLDA ; MELO, HERCILIO G. de. Microstructural characterization and corrosion behavior of a commercial friction stir welded AA2024-T3. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1199-1199.

    Abstract: Friction Stir Welding (FSW) arises as a great development by removing rivets, fasteners and lap joints areas, consequently, decreasing the aircraft weight. However, during the welding process, the plastic deformation and heat generation at the joint and surrounding areas lead to three distinct microstructural zones, namely, nugget or stir zone (SZ), thermo-mechanically affected zone (TMAZ), heat affected zone (HAZ), besides the base metal (BM). In these zones the microstructure of the material can be profoundly modified and localized corrosion phenomena can be more easily developed, which can be enhanced by local galvanic coupling due to changes in the microstructure as grain refinement and recrystallization, changes in the grain boundaries, dissolution and precipitation of hardening precipitates and dispersóides. In the present work, a commercial friction stir welded AA2024-T3 had its microstructure characterized by Electron Backscatter Diffraction (EBSD) technique and optical microscopy (OM). The corrosion behavior was investigated by exfoliation corrosion (EXCO) test and the intergranular corrosion susceptibility according to ASTM G110-97. After all tests, the samples were observed by scanning electron microscopy (SEM). EBSD results revealed the evolution of microstructure as a result of FSW. The base metal showed elongated grains along the rolling direction with a pancake-like non-recrystallized structure. The SZ undergone dynamic recrystallization showing finer equiaxed grains as a result of a significant plastic deformation and heating during the welding process. The TMAZ of the advancing side showed recrystallized finer grains, while the TMAZ of the retreating side showed coarse grains. Finally, the HAZ of both advancing and retreating sides showed grains typically elongated caused by the thermal input. The EXCO and intergranular tests showed a more intense attack in the TMAZ of the retreating side in agreement with the corrosion morphology observed by SEM.

    Palavras-Chave: friction welding; stirring; corrosion; microstructure; aluminium alloys; electron diffraction; backscattering

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  • IPEN-DOC 26128

    SILVA, SIRLANE G. ; FONTES, ERIC H. ; SILVA, JULIO C.M. ; ASSUMPÇAO, MONICA H.M.T.; OLIVEIRA NETO, ALMIR ; LINARDI, MARCELO . Fuel cell and electrochemical studies of the ethanol electro-oxidation in alkaline media using PtAuIr/C as anodes. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 387-387.

    Abstract: The use of fossil fuels has resulted in an increase of CO2 concentration in the atmosphere . It is well known that CO2 emission from fossil fuels is one of the principals responsible for the greenhouse effect. Taking these aspects into account,fuel cells might bean excelente alternative to the current energy generation as a clean and eficiente power source. In this context, alkaline fuel cells have attracted worldwide attention due to its promise to produce clean energy with high efficiency [1], thus direct etanol fuel cell could offer an alternative for electrical energy generation. In this work, ethanol electrooxidation reaction was investigated considering conventional electrochemical experiments in alkaline media, direct ethanol fuel cell (DEFC), and in situ ATRFTIR. The working electrode/anodes were composed of monometallic Pt/C, Au/C, Ir/C, and trimetallic PtAuIr/C nanoparticles with atomic Pt/Au/Ir ratios of 40:50:10, 50:40:10, 60:30:10, 70:20:10, and 80:10:10. X-ray diffraction (XRD) suggests PtAuIr/C alloy formation, and according to transmission electron micrographs, the mean particle sizes are from 4 to 6 nm for all catalyst compositions. PtAuIr/C 40:50:10 showed the highest catalytic activity for ethanol electro-oxidation in the electrochemical experiments; using this material, the peak current density from ethanol electro-oxidation on cyclic voltammetry experimente was 50 Ma per g of Pt, 3.5 times higher than that observed with Pt/C. The fuel cell performance was superior using all PtAuIr/C compositions than using Pt/C. Au/C and Ir/C presented very poor catalytic activity toward etanol electro-oxidation. The improved results obtained using PtAuIr/C might be related to the OHads species formed at low overpotential on Ir and to the decrease on adsorption energy of poisoning intermediates on Pt sites, promoted by Au.

    Palavras-Chave: electrocatalysts; fuel cells; electrochemistry; platinum; gold; direct ethanol fuel cells

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  • IPEN-DOC 26127

    MAGNANI, MARINA; GONÇALVES, HAROLDO M.; COSTA, ISOLDA ; BENEDETTI, ASSIS V.; FUGIVARA, CECILIO S.. Microstructural and electrochemical characterization of Friction Stir Welded aluminum alloys. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1191-1191.

    Abstract: Aluminum alloys of 2000 and 7000 series are extensively used in aircraft structures. However, these classes of aluminum alloys are difficult to join by conventional fusion welding techniques because the dendritic structure formed in the fusion zone can seriously compromise the mechanical and corrosion resistance properties of the joint. Friction Stir Welding (FSW) is attractive for joining high strength aluminum alloys since there is far lower heat input during the process compared with conventional welding methods. Frictional heat causes the metal to soften and allows the tool to traverse along the joint line. The FSW process generates three distinct microstructural zones: the nugget, the thermomechanically affected zone and the heat-affected zone. These microstructural modifications generally interfere in the performance of the corrosion resistance of welded alloys. In the present study, FSW was used to join two dissimilar aluminum alloys, AA2024-T3 and AA7475-T651 and the effect of this process on the corrosion resistance of the welded joints and on the microstructure of the alloys was evaluated. Microstructural characterization was carried out by optical microscopy, scanning electron microscopy and atomic force microscopy. The weld zone regions showed significant microstructural changes. Electrochemical impedance spectroscopy and Electrochemical noise measurements were used to evaluate the corrosion resistance of the different zones of the weld in NaCl solution. The electrochemical results showed that the corrosion behavior of the aluminum alloy is dominated by the electrochemical activity within the intermetallics (IMs). The weld zone regions containing copper IMs have a more noble character than the regions containing Zn and Mg IMs. Therefore, the results showed an increased susceptibility of welded joints to these forms of corrosion in comparison to the unaffected base metal by a more severe attack related to AA7475 alloy.

    Palavras-Chave: microstructure; electrochemistry; aluminium alloys; friction welding; stirring; welding; corrosion; corrosion resistance

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  • IPEN-DOC 26126

    REIS, SHIRLEY L. dos ; CARVALHO, SABRINA G. de M. ; MUCCILLO, ELIANA N. dos S. ; MUCCILLO, REGINALDO . Sintering under AC electric field of samarium doped ceria. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1064-1064.

    Abstract: Samarium doped ceria (SDC) is a high oxygen-ion conductor compound with application in solid oxide fuel cells operating at intermediate temperatures (500-700ºC). Polycrystalline SDC exhibits low sinterability, requiring high temperatures to achieve full densification under conventional sintering. Flash sintering is a recently developed method in which ceramic compacts may be sintered at lower temperatures and shorter times than those under conventional sintering. It consists in applying an electric field to a green compact, either during heating or at a fixed temperature up to the occurrence of an electric current pulse. In this study, samarium doped ceria (Ce0.8Sm0.2O1.9) was sintered by applying AC electric field at a fixed frequency of 1.0 kHz to the specimen during heating (dynamic sintering) or during a fixed temperature (isothermal). The influence of sintering on densification, microstructure and ionic conductivity was investigated. Similar density values were obtained for specimens sintered at 800ºC (dynamic) and 1100ºC (isothermal).

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  • IPEN-DOC 26125

    PIERETTI, EURICO F. ; CORREA, OLANDIR V. ; PILLIS, MARINA F. ; RAMANATHAN, LALGUDI V. . Electrochemical evaluation of the AISI 316 stainless steel coated by Nb2O5 thin films. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1465-1465.

    Abstract: Great number of metallic engineering materials form passive films on their surfaces and, therefore, are prone to localized corrosion, usually characterized by the occurrence of pits [1,2]. The improvement of surface properties is a requirement for the metallic components used, for example, in petrochemical industry, in fuel cells, and in nuclear plants. The goal of this work was to investigate the influence of Nb2O5 films deposited by DC magnetron sputtering during 15, 30 and 50 minutes on the electrochemical behavior of the AISI 316 austenitic stainless steel. The corrosion resistance was evaluated by monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and linear potentiodynamic polarization (LP) on an electrolyte composed of 0.1 M H2SO4 in water at 25 °C. Electrochemical tests showed that the coated specimens presented a more capacitive behavior, and were less susceptible to corrosion than specimens without Nb2O5 coatings. The OCP for coated samples at 50 min had the most inferior values. Similar results were obtained by Pillis et al. [3] for Nb2O5 coatings at 15 min and 30 min in NaCl solution. These results suggest that the obtained films have a protective behavior and can be used to avoid the degradation of the AISI 316 austenitic stainless steel in aggressive environments containing sulfur ions.

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  • IPEN-DOC 26124

    PIERETTI, EURICO ; CORREA, OLANDIR V. ; PILLIS, MARINA F. ; NEVES, MAURICIO M. das . Corrosion evaluation of an optical fiber laser treated stainless steel for biomedical applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 604-604.

    Abstract: The implant manufacturing process includes marking the final devices for their identification, long-term quality control and traceability. Marking is carried out after cleaning and prior to sterilization. These marks eventually can concentrate stress leading to premature failure. The marked areas are defective regions that affect the oxide layer formed on the biomaterials used for implants favoring the onset of various corrosion forms, such as pitting, crevice or fatigue [1, 2]. This study aims to evaluate the effect of an Yb optical fiber laser marking process on the localized corrosion resistance of the austenitic stainless steel ISO 5832-1 samples. This is one of the most used materials for implants manufacturing. The electrochemical behavior of the marked areas obtained by this method was evaluated in a phosphate buffered solution (PBS) with pH of 7.4 and the results were compared with non treated samples. All tested surfaces were prepared according to the recommendations for clinical use. For localized corrosion resistance evaluation, electrochemical tests as monitoring the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and cyclic potentiodynamic polarization measurements were performed. The results showed that the laser marks affects the protector characteristics of the biomaterial’s passive film. Lower pitting resistance was associated to the laser marked areas, because of its roughness changes.

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  • IPEN-DOC 26123

    MUCCILLO, ELIANA N. dos S. ; GROSSO, ROBSON L. ; MUCHE, DERECK N.; CASTRO, RICARDO H.. Nanostructured scandia stabilized zirconia consolidated by high-pressure spark plasma sintering. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 54-54.

    Abstract: Scandia-stabilized zirconia, ScSZ, is an oxide-ion conductor with high ionic conductivity at relatively low temperatures (about 500 ºC). The consolidation of this ionic conductor requires high temperatures to achieve high densification, due to its low sinterability. Moreover, ScSZ exhibits a complex phase diagram for compounds up to 10 mol% scandia, including an ordered rhombohedral phase with low ionic conductivity. In this work, fully dense ScSZ specimens were obtained by high-pressure spark plasma sintering using deformable punches (DPSPS). Nanocrystalline powders containing 6, 8 and 10 mol% scandia were synthesized by simultaneous precipitation followed by heat treatment at 500ºC for 2 h. The mean grain sizes of specimens consolidated by DP-SPS at 700 and 800ºC and at 1.5 and 2 GPa, varied from 8 to 17 nm. The grain size dependent cubic phase stabilization was evidenced by Raman spectroscopy. High degree of translucence was obtained in dense specimens of ScSZ obtained by the DP-SPS method.

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  • IPEN-DOC 26122

    SILVA, PAULO M. ; ESPOSITO, VINCENZO; MARANI, DEBORA; FLORIO, DANIEL Z. de; FONSECA, FABIO C. . Ceria-based ceramic composites for high temperature thermochemical applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 989-989.

    Abstract: Among thermochemical conversion processes, the production of fuels such as H2 via solar thermochemical cycles is potentially more efficient and more economical than the use of electric energy to electrolyze water. The principle of solar thermochemical cycles is based on the remarkable properties of some oxides, which can be reduced and oxidized cyclically (redox cycles), i.e., releasing and absorbing oxygen under certain temperature (or pressure) regimes. These redox cycles can be efficiently used to convert H2O (or CO2) to H2 (CO). Thermochemical redox cycles avoid the problematic step of fuel / O2 separation and allow operation at more moderate temperatures (~ 1500 K) [1]. In this work, a new material concept for the separation of high temperature H2O based on porous ceramic composites composed of an ultra-high temperature ceramic phase (UHTC) and doped cerium oxide is proposed. UHTC usually exhibit extremely low mass diffusion rates and excellent thermomechanical properties for high temperature applications [2]. Gadolinium-doped ceria (CGO) presents unique processes at low oxygen partial pressure (pO2 < 10-12 atm) and high temperatures (T > 800 °C) such as faster mass diffusion, which are not observed in conventional sintering under ambient air conditions. In CGO/Al2O3 composites the resulting effects driven by such mass diffusion are low viscosity flows and high reactivity between phases, indicated by the formation of CeAlO3[3]. In this work, a comparison is made between sintering CGO/Al2O3 under ambient air and reducing condition, focusing on densification, viscosity and the evolution of the microstructure. The redox process of CGO/Al2O3 is investigated using dilatometry, microscopy, and electrochemical impedance spectroscopy. The preliminary results evidenced that new phases with remarkable microstructure can be obtained at reducing atmosphere depending on the temperature of reoxidation during cooling

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  • IPEN-DOC 26121

    VALLI, RICARDO; OLIVEIRA, FELIPE S.; OTUBO, LARISSA ; LANG, ROSSANO. CrSi2 layer synthesized by high current Cr ion implantation for Schottky diode applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1135-1136.

    Abstract: Among the transition-metal silicides, CrSi2 has received considerable attention as a material for silicon-based technologies because of its high-temperature stability, oxide-forming ability and semiconducting properties [1]. Its use in infrared photodetectors and Schottky barrier contacts has been of interest. Previous studies indicate that bulk CrSi2 has a hexagonal structure and p-type semiconductor character with a band gap of ≈ 0.35 eV [2]. In this work, we have synthesized and investigated the electrical-structural correlation of CrSi2 buried layer produced by high current Cr ion implantation. For this, Cr+ ions at an energy of 180 keV were implanted at high temperature (550 °C) at a fluence of 4x1017 ion/cm2. An n-type (001) surface-oriented Czochralski Si wafer (thickness 500 mm, resistivity 10-20 Ωcm) was used as host matrix. The chromium beam current density during implantation was about 6 μA/cm2. The Schottky diode formation consisted of the junction of metal and semiconductor, in this case, Au contact, and the CrSi2/Si, respectively. The formation of the crystallographic phase was identified by grazing incidence Xray diffraction. The buried layer morphology of silicide into substrate subsurface was revealed through scanning electron microscopy. Electrical conduction was characterized by resistivity measurements as a function of temperature (50 - 300 K), where two types of regimes are observed, i.e., two gaps: one of low temperature and one of high temperature (270 K). The electronic mobility was also obtained as a function of temperature by means Hall effect measurements. The transport of electrons above the potential barrier to the metal (Schottky barrier height), was determined by current-voltage curves (IxV) at room temperature.

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  • IPEN-DOC 26120

    FUJIMOTO, TALITA G. ; MUCCILLO, ELIANA N. dos S. . Effect of Pr on microstructure and dielectric properties of SrTiO3. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 146-146.

    Abstract: Polycrystalline ceramics based on strontium titanate (SrTiO3) have attracted great attention in recent years due to their interesting dielectric properties, e.g. high electric permittivity and low dielectric loss. SrTiO3 has many applications in electronic devices, sensors, actuators, fuel cells, among others. Recently, the effects of dopants on the dielectric properties of SrTiO3 have been investigated. Lui et al. [1] were the first to report a giant electric permittivity in Sr0.09Pr0.01TiO3 (> 3,000) at room temperature. In this work, the effect of Pr (0.025, 0.05 and 0.075% mol Pr) on the microstructure and dielectric properties of SrTiO3 was studied in detail. Samples were characterized by density measurement, X-ray diffraction, scanning electron microscopy and impedance spectroscopy. The results show that sintered samples at 1500 ºC/6 h exhibit high densities (> 96% of the theoretical value), independent on the additive content. The average grain size of SrTiO3 increases slightly with Pr addition. Specimens containing 0.075% mol Pr show high giant permittivity (about 30,000) at 540 ºC.

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  • IPEN-DOC 26119

    CARVALHO, SABRINA G. de M. ; MUCCILLO, REGINALDO ; MUCCILLO, ELIANA N. dos S. . Flash sintering of 3 mol% yttria-stabilized zirconia with AC and DC electric fields. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1062-1062.

    Abstract: Experiments on sintering ZrO2: 3 mol% Y2O3 polycrystalline ceramics (Y-TZP), pressed to cylindrical pellets, were carried out by heating to 1000 oC for application of a DC and AC (1 kHz) electric field (isothermal electric field-assisted sintering) of 200 V.cm-1 for 30 seconds, and 2 A as current limit. The experiments were carried out positioning cylindrical specimens inside a vertical dilatometer, with platinum meshes at the parallel surfaces connected with platinum wires to a power supply. Both 3YSZ sintered samples, besides having their apparent densities determined, had their surfaces observed in a scanning electron microscope to evaluate average grain size and distribution of grain sizes. Moreover, impedance spectroscopy analyses were carried out to evaluate the intergranular (mainly grain boundary) and intragranular (bulk) contributions to the electrical resistivity. The results show that besides both samples present similar densities and electrical resistivity, the one submitted to AC electric fieldassisted sintering presented smaller grains sizes and a discrete grain size distribution when compared to the one sintered with DC electric field.

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  • IPEN-DOC 26118

    CARVALHO, SABRINA G. de M. ; MUCCILLO, REGINALDO ; MUCCILLO, ELIANA N. dos S. . Electrical behavior and microstructural features of conventionally and electric field-assisted sintered 3 mol% yttria-stabilized zirconia. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 286-286.

    Abstract: ZrO2: 3 mol% Y2O3 ceramic powders, pressed to cylindrical pellets, were sintered conventionally at 1400oC (CS) and by applying an AC electric field in green (FS) and in pre-sintered (CS-FS) pellets. The electric field (200 V.cm-1, 1 kHz frequency, 3 A limiting current) was applied at 1000oC. The experiments were carried out positioning cylindrical specimens inside a vertical dilatometer furnace, with platinum meshes at the parallel surfaces connected with platinum wires to a power supply. The density of CS, FS and CS-FS were 98.9, 98.6 and 99.1% of theoretical density respectively. The average grain size were 282±73, 340±108 and 387±138 nm for conventionally sintering, conventionally follow by flash sintering and only flash sintered samples. Although the samples have close density values, the bulk and grain boundary conductivities of samples submitted to electric field assisted sintering are higher than conventional sintered sample. The intragranular and intergranular conductivities obtained by electrochemical impedance spectroscopy of CS, FS and CS-FS samples were 8.7 and 9.8, 9.4 and 10.2 and 13.7 and 29.6 kΩ.cm, respectively. These results show that the application of an AC electric field to a green or pre-sintered solid electrolyte enhances its ionic conductivity due to the welding of the grains and the increased in the oxide ion concentration due to diffusion to the grains of the chemical species depleted at the space charge region, enhancing the oxide ion concentration, both phenomena are provoked by the Joule heating produced by the electric current flow.

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  • IPEN-DOC 26117

    QUEIROZ, CARLOS A. da S. . Preparation of high purity cerium precursors for use in automotive catalysts. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1231-1231.

    Abstract: Starting with a fraction of mixed rare earths chloride with 47% in CeO2 , high pure cerium oxide and acetate was prepared. The mixed rare earths chloride solution was treated by fractionated precipitation technique. Cerium (III) was oxidized to cerium (IV) by addition of hydrogen peroxide. The acidity liberated in the hydrolytic process was neutralizes with NH3 stream generated by compressed air injected into the 1M NH4OH solution and bubbled into the rare chlorides solution. The temperature was maintained at 60oC. After the complete cerium hydroxide precipitation, it was separated by filtration. This hydroxide precipitate enriched in cerium (90% in CeO2) was dissolved in hydrochloric acid and the cerium chloride solution was used as the feeling solution to a strong cationic ion exchanger resin system. After loading the resin with de cerium, it was rinsed with water and eluted the ions by complexation with ammonium salt of EDTA adjusted to pH 4,0. Free EDTA acid was precipitated by addition of chloride acid to the cerium complex eluted and it was separated by filtration. The ultimate cerium chloride solution was treated with oxalic acid and the cerium oxalate separated, dried and fired to cerium oxide. The highly pure cerium oxide prepared (99.9%) was directly dissolved with hot concentrated acetic acid.The typical cerium acetate obtained contain the followings contaminants in micrograms per gram: Y(4.1 ), Sc (15.4 ), La (32.4), Pr (14.6), Nd (6.5), Sm (9.7), Eu (5.3), Gd (9.2), Tb (6.2), Dy (5.4), Ho (0.08) Er(0.9), Tm (0.2),Yb ( 20.5), Lu (2.3).

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  • IPEN-DOC 26116

    NASCIMENTO, MAURICIO S.; SANTOS, GIVANILDO A. dos; SOUZA, PAULO E.S.; FRAJUCA, CARLOS; NAKAMOTO, FRANCISCO Y.; SILVA, MARCIO R. da; SANTOS, VINICIUS T. dos; BATALHA, GILMAR F.; COUTO, ANTONIO A. . Correlation between microstructure, thermal parameters and hardness of a directionally solidified Al-Si-Cu alloy. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1123-1124.

    Abstract: Metals solidification involves the transformation of the molten metal back into the solid state. Solidification structures impact heavily on the final product’s characteristics. The microstructure effects on metallic alloys properties have been highlighted in various studies and particularly the dendrite arm spacing influence upon the mechanical properties such as hardness has been reported [1-3]. The aim of this work is to obtain correlations between microstructure and the hardness of Al-10wt%Si-2wt%Cu alloy casting. Initially, the alloy was formed by aluminum, copper and silicon commercially pure, fused in a clay-graphite crucible with an electric muffle furnace. After melting the mixture was poured into stainless steel AISI 304 chill and solidified under upward unsteady state heat flow conditions. Heat was directionally extracted only through a water-cooled bottom made of steel (SAE 1020). The experimental results include solidification thermal parameters such as volume fraction of the eutectic mixture, primary dendritic arm spacing and hardness.It is found that the hardness decreases with the increase of the primary dendritic spacing and with the decrease of the eutectic mixture fraction.

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  • IPEN-DOC 26115

    TABUTI, FRANCISCO N. ; PEREIRA, VICTORIA B. ; PIAZZOLLA, FERNANDO ; FONSECA, FABIO C. . Development of ceria-based direct ethanol intermediate-temperature solid oxide fuel cell. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 142-142.

    Abstract: Solid oxide fuel cells (SOFCs) have several advantages over traditional energygenerating devices. A key property is the possibility of using various fuels such as natural gas and ethanol, which are strategic for Brazil. This study addresses two aspects that need to be improved in SOFC: (a) the high operating temperature of the cell that brings several problems for assembly and operation of a power system, and (b) the deactivation of the cell due to the deposition of carbon on the surface of the nickel anode when the cell is fed with carbon-containing fuels. The properties of ceria-based/Ni cermets both as the anode material and as the catalytic layer for bio-ethanol fueled SOFC with yttria-stablilized zirconia electrolyte were investigated. Ceria-based/Ni cermets were studied as the catalytic layer deposited onto the standard yttria-stabilized zirconia/Ni anode for direct ethanol SOFCs. Properties of both Zr- and Nb-doped (10 mol%) ceria / Ni (15 vol%) cermets were investigated as the catalytic layer in direct ethanol SOFCs. Electrolyte-supported fuel cells with doped-ceria /Ni catalytic layer were tested for ~100 hours under (dry) ethanol. Fuel cells using the different ceria/Ni cermets showed excellent stability on ethanol. The promising results obtained with ceria-based anodes for SOFC of ethanol motivated the development of ceriabased SOFCs. Thus, intermediate-temperature SOFCs using doped-ceria electrolytes have been tested at 600 °C using hydrogen. Preliminary results show that direct ethanol SOFC are promising devices for efficient energy conversion at intermediate temperatures.

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  • IPEN-DOC 26114

    GUIMARAES, MARCOS de A.; SANTOS, GIVANILDO A. dos; AGUIAR, HERBERT C.G. de; SUYAMA, DANIEL I.; SILVA, MARCIO R. da; SANTOS, VINICIUS T. dos; NAKAMOTO, FRANCISCO Y.; FRAJUCA, CARLOS; BATALHA, GILMAR F.; COUTO, ANTONIO A. . Behaviour of PVD multi-layer coating carbide inserts in dry machining of nickel aluminium bronze alloy. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1459-1459.

    Abstract: The aluminium bronze alloys have machinability rate from 20 to 40% compared to free cutting brasses, so the cutting parameters and type of tools suitable for machining of these materials may be very different in comparison with other copper alloys. In this study was evaluated the flank wear rate of multi-layer PVD coating carbide insert in dry machining of nickel aluminium bronze CuAl10Ni5Fe5. The new advanced nano-layer coatings composed of numerous layers of the same, or combinations of different coating types can reduce dramatically the tool flank wear compared to conventional monolayer coatings [1]. The CuAl10Ni5Fe5 alloy was machining by CNC turning at different cutting speeds (cutting conditions). The surface and wear of carbide inserts were analysed by Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDS). The results showed very small flank wear produced by abrasion on the cutting edge even with the increase of cutting speed from 80 to 450 m/min.

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  • IPEN-DOC 26113

    QUEIROZ, CARLOS A. da S. . Synthesis and characterization of neodymium acetate for use in nanotechnology. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 1222-1222.

    Abstract: A simple and economical chemical process to obtaining neodymium acetate of high purity was studied. The raw material in the form of mixed rare earths carbonate comes from Brazilian monazite. It was used the technique of strong cationic exchange resin, proper to water treatment to the neodymium''s fractionation and it is achieved a purity of 99.9% in Nd2O3 and yield greater than or equal 80%, with the elution of rare earths by EDTA solution in pH controlled. The complex of EDTA-neodymium is transformed in neodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the neodymium acetate. The solid salt was characterized via chemical analysis, thermal analysis, X ray diffraction, infrared spectroscopy and inductively coupled plasma mass spectrometry to certify the purity.The analytical data collected allowed to conclude that the stoichiometric formula for the compound is Nd(CH3COO)3.1.5H2O. The typical neodymium acetate obtained (purity ≥ 99.9%) contain the followings contaminants in micrograms per gram: Y(0.9), Sc (5.1), La (1.0), Pr (3.4), Sm (12.8), Eu (1.1), Gd (15.4), Tb (2.9), Dy (5.3), Ho (7.4) Er(1.5), Tm (0.3),Yb ( 2.5), Lu (1.0).

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  • IPEN-DOC 26112

    SILVA, THAMYSCIRA H.S.; GRILO, JOÃO P.F.; ARAUJO, ALLAN J.M.; LOUREIRO, FRANCISCO J.A.; FAGG, DUNCAN P.; FONSECA, FABIO C. ; MACEDO, DANIEL A.. Structure, densification and electrical properties of Gd3+ and Cu2+ co-doped ceria solid electrolytes for SOFC applications. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 911-912.

    Abstract: The current energy needs are still met by the use of fossil fuels. Due to the increasing demand for new energy sources, solid oxide fuel cell has proven to be a good alternative. However, the development of this technology is limited by needs high operation temperature. Ceria-based solid electrolytes have been considered a promising material due to better ionic conductivities in comparison to traditional yttria-stabilized zirconia ceramics. The main disadvantage of ceriabased electrolyte is the need for high sintering temperatures for complete densification. Transition metal oxides exhibiting low melting points, such as CuO, have been used as additives to lower the sintering temperature of these materials [1]. In this scenario, the present work is focused on the evaluation of the effects of gadolinium oxide (Gd2O3) content and small quantity of CuO on the structure, densification and electrical properties of ceria solid solutions [2]. Nominal compositions of Ce0.99−xGdxCu0.01O2-δ (0≤x≤0.3) were synthesized by the polymeric precursor method. The calcined powders were studied by XRD and Rietveld refinement to obtain crystallographic parameters. The sinterability of green bodies was evaluated by dilatometry up to 1200 °C. The electrical properties were investigated by impedance spectroscopy. The electrical conductivity was enhanced by gadolinium addition, reaching a maximum of 7.81 mS cm−1 at 600 °C for the composition x=0.15 sintered at a temperature as low as 1050 °C.

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  • IPEN-DOC 26110

    REY, JOSE F.Q.; MATOS, BRUNO R. ; LONGO, ALESSANDRO; FONSECA, FABIO C. ; MERINO, DANIEL H.. Nafion/CsHSO4 hybrids SAXS/ WAXS/ XAS studies. In: BRAZILIAN MRS MEETING, 17th, September 16-20, 2018, Natal, RN. Abstract... São Carlos: Aptor Software, 2018. p. 230-230.

    Abstract: Nafion (Developed by DuPont) has been largely employed as solid electrolytes in Polymer Electrolyte Membranes (PEM) fuel cell applications. However, mild conditions (intermediates temperatures (~80 C), high relative humidity, and pure hydrogen fuel) are required to yield high fuel cell performances [1]. Nafion-based hybrid materials have been suggested as potential candidates to improve the performance of PEM fuel cells at higher temperatures and lower humidity conditions whilst maintaining the chemical stability and mechanical strength of the standard electrolyte. Hybrid materials are generally synthesized by the incorporation of hydrophilic inorganic nanoparticles in the polymer structure aiming at PEM operating above 100 °C [2]. The precursor solution impregnates the Nafion membrane and a subsequent thermal treatment induces the nucleation and growth of the nanoparticles inside the membrane. In the last decade, great efforts have been focused on the investigation of the property-structure relationship to improve the technological applications [3]. The aim of our study is to study the mechanism of growth of the nanoparticles embedded at the Nafion membranes by SAXS (Small Angle X Ray Scattering)/ WAXS (Wide Angle X Ray Scattering) as well as to understand the chemical environment of the nanoparticles within the polymeric internal structure by XAS (X Ray Absorption Spectroscopy) in the Caesium (Cs) K-edge. The main results shown a strong relationship between the hybrid membranes morphology and the concentration/synthetic route of the inorganic species.

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  • IPEN-DOC 26090

    ROLINDO, N.C. ; TESSARO, A.P.G. ; SMITH, R.B. ; CAMPOS, C.; MARUMO, J.T. ; VICENTE, R. . Disused sealed radioactive sources: inventory and characterization at IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26089

    MORAES, MARCIA C.D. ; PEREIRA, DAISA L. ; ANA, PATRICIA A. da; FREITAS, ANDERSON Z. de ; ZEZELL, DENISE M. . Optical attenuation coefficients obtained through OCT correlates to microhardness in dental human enamel irradiated with Nd: YAG and submitted to demineralization in vitro. In: RECHMANN, PETER (Ed.); FRIED, DANIEL (Ed.) SPIE PHOTONICS WEST; SPIE BIOS, February 2-7, 2019, San Francisco, USA. Abstract... Washington, USA: SPIE, 2019. (Proceedings SPIE 10857, Lasers in Dentistry XXV).

    Abstract: This work aims was to correlate the changes in the optical attenuation coefficients obtained through the OCT technique with the values obtained in Knoop sectional microhardness tests over time in dental human enamel samples irradiated with the Nd: YAG laser and Acid Phosphate Fluoride (APF), aiming the prevention of caries lesions in vitro. After Ethical Committee approval, 160 enamel samples, obtained from 40 human tooth molars, were divided into 4 groups: Control group (where no treatment was performed); Fluoride group (APF - fluoride phosphate acidulated for 4 minutes); Fluoride-Laser group: APF followed by irradiation with Nd:YAG laser (DE = 84.9 J/cm2, contact mode, with the use of carbon paste as photoabsorver); Laser-fluoride group (irradiation with Nd:YAG laser followed by APF). The samples of all groups were subjected to pH cycling during 20 days. On days 5, 10, 15 and 20, 10 samples from each group were removed from the cycling for the Knoop sectional microhardness test. Two samples of each group, at each time, were randomly selected for the analysis with FTIR-ATR (Fourier transform infrared spectroscopy associated with attenuated total reflection technique). The analysis by ATR-FTIR showed changes in the chemical composition of the samples of the irradiated groups in relation to Control and Fluoride group. There was correlation between the values of sectional microhardness tests and the measured optical attenuation coefficient by OCT in irradiated dental enamel, showing that the association between fluoride application and Nd:YAG laser irradiation is an important tool for the prevention of tooth enamel demineralization.

    Palavras-Chave: tomography; coherent radiation; teeth; caries; neodymium lasers; enamels; fluorides; demineralization; irradiation; attenuation

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  • IPEN-DOC 26088

    MAYNARD, ISABELLA F.N.; CAVALCANTI, ELIANE B.; MARTINS, ELAINE A.J. ; SILVA, LARISSA L. da ; PIRES, MARIA A.F. ; MARQUES, MARIA N.. Avaliação da presença de desreguladores endócrinos em água subterrânea e tratada em uma área rural. In: ARENZON, ALEXANDRE (Ed.); NUNES, MARIA E.T. (Ed.); BOTTA, CLARICE M.R. (Ed.); ESPINDOLA, EVALDO L.G. (Org.); NOVELLI, ANDREA (Org.) CONGRESSO BRASILEIRO DE ECOTOXICOLOGIA, 15th, 1-4 de setembro, 2018, Aracaju, SE. Resumo expandido... Campinas: Sociedade Brasileira de Ecotoxicologia, 2018. p. 672-674.

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  • IPEN-DOC 26073

    ALBANO, A.M.S. ; ARTHUR, V. . Efeito da radiação gama na inibição da germinação de ervilha in natura (Pisum sativum L.). In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26072

    CAMPOS, R.F. ; CAMPOS, V.P. ; MITAKE, M.B. ; ARAUJO, E.B. . Analise dosimétrica de um laboratório de radiobiodistribuição in vivo usando CaSO4:Dy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26071

    SILVA, T.M. ; KODAMA, Y. ; SOMESSARI, S.L. ; OMI, N.M. ; NORMANTON, K.A.F. ; VASQUES, F.M.F. ; DUARTE, C.L. ; SAMPA, M.H.O. ; CALVO, W.A.P. . Desenvolvimento de procedimentos e metodos de monitoração individual e de área em uma unidade móvel de irradiação por feixe de elétrons. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: waste management; water pollution; industrial wastes; water treatment; chemical effluents; organic wastes; chemical wastes; ionizing radiations; radiodisinfestation; radiation doses; microorganisms; electron beams; monitoring; water pollution monitors; implementation; brazilian cnen

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  • IPEN-DOC 26070

    COELHO, ANASTACIA L.L.P.B. ; PINHEIRO, ANGELICA L.L.P. ; SIMPSON, STEPHANIE C.; ZEITUNI, CARLOS ; ROSTELATO, MARIA E.C.M. . A radiação ionizante como forma de tratamento nas mulheres com câncer de colo de útero em Araguaína –TO nos anos de 2000 a 2015. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Abstract: O câncer vem se apresentando como um grave problema de saúde pública em todo mundo as sociedades globais, especialmente em países subdesenvolvidos. Em 2005, de um total de 58 milhões de mortes ocorridas no mundo, o câncer foi responsável por 7,6 milhões (13%). Desse total, mais de 70% ocorreram em países de média ou baixa renda. Atualmente, o câncer é a segunda causa de morte no Brasil (10,3% do total), excluídas as causas indeterminadas, ficando atrás somente de doenças cardiovasculares . Para 2018, há uma estimativa de 16.370 novos casos, sendo que, 2.300 se encontram na região Norte do país. O câncer de colo uterino é o segundo tipo de câncer mais frequente entre as mulheres em todo o mundo. A sua frequência, entretanto, é bastante variável de acordo com o desenvolvimento do país estudado, sendo que 83% dos casos registrados no mundo acontecem em países em desenvolvimento, onde o risco cumulativo é de 1,5% aos 65 anos. Este trabalho trata-se de um estudo descritivo, retrospectivo, quantitativo-interpretativo, com analise de dados secundários do período de 2000 a 2015 do Registro Hospitalar de Câncer pelo Sistema de Informação em Saúde (SIS-RHC), vinculado ao Hospital Regional de Araguaína. Os dados foram tabulados em planilhas eletrônicas do excel onde foram obtidas variáveis estatísticas e frequência para análise. . Foram analisadas 2.664 mulheres com câncer de Colo de Útero no Hospital Regional de Araguaína. Sendo divididas em 17 variáveis na “Ficha de Tumor”; o histórico de bebida alcoólica e de tabaco apresentaram as maiores porcentagens de ausência de preenchimento (mais de 31%). Em seguida, 25,9% das fichas não tiveram o preenchimento da escolaridade. De uma forma geral, pode-se notar que das 17 informações utilizadas neste estudo, 55,7% das fichas continham todas as informações e 12, 2% tinham 4 ou mais informações ausentes. Observa-se entre o tempo de diagnóstico e tratamento que as mulheres diagnosticadas tardiamente apresentaram, em média, tempos maiores entre as duas ações. a maioria das pacientes tiveram um diagnóstico tardio, com isso a radioterapia se tornou a principal forma de tratamento.

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  • IPEN-DOC 26069

    ALVARENGA, T.S. ; POLO, I.O. ; PEREIRA, W.W.; CALDAS, L.V.E. . Anisotropia da fonte de 241AmBe do laboratório de calibração com nêutrons do IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: anisotropy; americium 241; beryllium; calibration; neutron detection; measuring instruments; brazilian cnen; radiation protection

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  • IPEN-DOC 26068

    LITVAC, D. ; CALDAS, L.V.E. . Caracterização dosimétrica do LiF-nrpb para calibração de aplicadores clínicos de betaterapia. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: radiotherapy; personnel; occupational safety; beta dosimetry; lithium fluorides; brazilian cnen; dosimetry; radiation doses; calibration; recommendations; beta radiography

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  • IPEN-DOC 26067

    SANTOS, W.S.; NEVES, L.P.; PERINI, A.P.; CALDAS, L.V.E. . Uso de modelagem computacional para avaliação da exposição médica e ocupacional durante procedimento de cardiologia intervencionista. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: fluoroscopy; biomedical radiography; cardiovascular system; images; medical personnel; patients; radiation doses; radiation protection; occupational safety; computer codes; programming

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  • IPEN-DOC 26066

    CASTRO, M.C. ; SILVA, N.F. ; CALDAS, L.V.E. . Some characterization tests for an extrapolation chamber in CT standard beams in a specific chamber depth. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: radiation detectors; computerized tomography; diagnostic uses; ionization chambers; calibration standards; x radiation; radiation doses; radiation quality; extrapolation chambers

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  • IPEN-DOC 26065

    ANTONIO, P.L. ; CALDAS, L.V.E. . Comportamento do sinal TL/OSL e PTTL/PTOSL após tratamento térmico pós-irradiação com fonte de 60Co, em amostras de LiF:Mg,Ti e CaSO4:Dy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: dosimetry; thermoluminescence; optical equipment; ultraviolet radiation; radiation detection; heat treatments; cobalt 60; thermoluminescent dosemeters; thermoluminescent dosimetry

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  • IPEN-DOC 26064

    LIMA, B.L.; ALMEIDA, J.S. ; POTIENS, M.P.A. ; PELISSONI, R.A.; SAPIENZA, M.T.; BUCHPIGUEL, C.A.; WILLEGAIGON, J.. Evaluation of biokinetics and dosimetry in [131I]-NaI therapies: whole-body images quantification versus lower limb region. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26063

    TAVARES, P.S. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Princípio de investigação do dosímetro Fricke Gel modificado utilizando um equipamento de CT Óptico. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26062

    SAUEIA, C.H.R. ; NISTI, M.B. ; MAZZILLI, B.P. . Determinação de Cs-137 e radionuclídeos naturais em sedimentos do Sistema Estuário da Baixada Santista, Brasil. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26061

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CINTRA, F.B. ; CALDAS, L.V.E. . Simulation of a TH-GEM based detector for standard mammography-quality beam dosimetry using the MCNP5 code. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

    Palavras-Chave: electron multiplier detectors; beams; dosimetry; mammary glands; monte carlo method; radiation transport; x radiation; shielding; dosemeters; thickness

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  • IPEN-DOC 26060

    SILVA, E. ; SANTOS, L.R. ; ASSEMANY, L.P.F. ; POTIENS, M.P.A. . Evaluation of the performance of radioprotection ionization chambers used in radiometric survey of radiology clinical systems. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26059

    NISTI, M.B. ; CAMPOS, M.P. ; SILVA, G.M. ; MAZZILLI, B.P. . Determinação da taxa de exalação do 222Rn no solo do IPEN. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26058

    TAMURA, T.M.; SOUZA, R.E.; NEVES, L.P.; PERINI, A.P.; SANTOS, W.S. . Cálculo de fator de conversão para dose absorvida em atividade de navegação utilizando o método Monte Carlo e um simulador antropomórfico virtual. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26057

    CORREIA, R.W. ; ROSTELATO, M.E.C.M. ; ZEITUNI, C.A. . Estudo e calibração de detector HPGe para análise radionuclídica de iodo-125. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26056

    ABREU, R.T. ; ANGELOCCI, L.V. ; NOGUEIRA, B.R. ; SANTOS, H.N. ; ZEITUNI, C.A. ; ROSTELATO, M.E.C.M. . Dose-rate constant evaluation of a new 192-Ir brachytherapy source using Monte-Carlo and experimental parameters. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26055

    BAPTISTA, T.S. ; ZEITUNI, C.A. ; RODRIGUES, B. ; MOURA, J. ; ROSTELATO, M.E. . Efficiency test on three types of sanitizers for cleaning sealed radioactive sources for brachyterapy. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26054

    ANDRADE, M.A.B.; ALVES, C.O.; FIN, A.P.C.; SOARES, F.A.P.; SAVI, M. ; POTIENS, M.P.A. . Visual impact of infill percentages for 3D printed radiologic simulators. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26053

    PRADO, E.S.P. ; MIRANDA, F.S.; PETRACONI, G.; POTIENS JUNIOR, A.J. . Tratamento de rejeitos radioativos compactáveis aplicando a tecnologia plasma para redução volumétrica. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26052

    MARTINS, E.W. ; BUENO, L.K. ; POTIENS, M.P.A. . Implementação de uma instalação para implantação da nova metodologia de calibração de ativímetros. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26051

    DIAS, A.J.R. ; VILELA, A.N. ; VICENTE, R. ; DELLAMANO, J.C. . Acidentes radiológicos: dados que auxiliam a proteção radiológica. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26050

    OLIVEIRA, J.J. ; VICENTE, R. . Relevância radiológica relativa: Angra 1 e 2. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26049

    TESSARO, A.P.G. ; SMITH, R.B. ; ROLINDO, N.C. ; VICENTE, R. . Opening the Goiania accident unburied waste packages. In: INTERNATIONAL JOINT CONFERENCE RADIO, September 16-20, 2019, São Paulo, SP. Resumo expandido... Maringá, PR: Sociedade Brasileira de Proteção Radiológica, 2019.

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  • IPEN-DOC 26048

    GASPARIAN, P.B.R. ; YOSHIMURA, E.M.; UMISEDO, N.K.; CAMPOS, L.L. ; MALTHEZ, A.L.M.C.. Study of the dosimetric properties of CaSO4:Dy using OSL technique. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 326-326.

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  • IPEN-DOC 26047

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

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  • IPEN-DOC 26046

    POLO, IVON O. ; CALDAS, LINDA V.E. . SOL-GEL α-Al2O3 detectors: TL and OSL response to beta radiation beams. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 317-317.

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  • IPEN-DOC 26045

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

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  • IPEN-DOC 26013

    ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Phototransfer analysis on TL and OSL responses of LiF:Mg,Ti (TLD-100) after exposure to 60Co radiation. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 302-302.

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  • IPEN-DOC 26012

    ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Influence of the thermal treatment on the PTTL and PTOSL signals from different natural materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 301-301.

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  • IPEN-DOC 26044

    VILLANI, D. ; MORENO, C.S.; SAKURABA, R.K.; GONÇALVES, V.D.; CAMPOS, L.L. . Optically stimulated luminescence dosimetry characterization with clinical photon beams and LINAC measurements. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 299-299.

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  • IPEN-DOC 26043

    VENEZIANI, G.R. ; MATSUSHIMA, L.C.; GAGLIARDO, K.M.; CARVALHO, T.P.A.; SAKURABA, R.K.; CAMPOS, L.L. . Development of phantom using 3D printer for veterinary radiosurgery. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 297-297.

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  • IPEN-DOC 26042

    SILVA, NATALIA F. ; SILVA, TIAGO F.; CASTRO, MAYSA C. ; LUZ, HUGO N. da; CINTRA, FELIPE B. ; CALDAS, LINDA V.E. . Simulation of geometry and materials of the TH-GEM based detector for radiation dosimetry. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 253-253.

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  • IPEN-DOC 26041

    BARRERA, GERARDO R.; ALMEIDA, ADRIEL S.; JUNOT, DANILO O. ; SOUZA, DIVANIZIA do N.. Synthesis and TL and OSL characterization of (MgB2O4-MgB4O7): Ce:Li and (MgB2O4-MgB4O7): Dy:Li glasses for dosimetry. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 216-216.

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  • IPEN-DOC 26040

    NASCIMENTO, BRUNA C.; FRIMAIO, AUDREW ; BARRIO, RAMON M.M.; SIRICO, ANA C.A.; COSTA, PAULO R.. Comparative analysis of the transmission properties of radiologically equivalent materials. In: RUBIO, MARCELO (Ed.); TIRAO, GERMAN (Ed.) INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 14th, October 7-11, 2018, Córdoba, Argentina. Abstract... Córdoba: Centro de Excelencia en Productos y Procesos, 2018. p. 212-212.

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

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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

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

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

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

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