Eventos - Resumos: Recent submissions

  • IPEN-DOC 27019

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

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

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  • IPEN-DOC 27018

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

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

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  • IPEN-DOC 27017

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

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

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  • IPEN-DOC 27016

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

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

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  • IPEN-DOC 27015

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

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

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  • IPEN-DOC 27014

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

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

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  • IPEN-DOC 27013

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

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

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  • IPEN-DOC 27012

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

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

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  • IPEN-DOC 27008

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

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

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  • IPEN-DOC 27007

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

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

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  • IPEN-DOC 26993

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

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

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  • IPEN-DOC 26990

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

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

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  • IPEN-DOC 26985

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

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

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  • IPEN-DOC 26983

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

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

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  • IPEN-DOC 26981

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

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

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  • IPEN-DOC 26980

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

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

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  • IPEN-DOC 26979

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

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

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  • IPEN-DOC 26978

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

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

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  • IPEN-DOC 26977

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

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

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  • IPEN-DOC 26976

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

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

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  • IPEN-DOC 26975

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

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

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  • IPEN-DOC 26974

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

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

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  • IPEN-DOC 26973

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

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

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  • IPEN-DOC 26972

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

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

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  • IPEN-DOC 26971

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

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

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  • IPEN-DOC 26970

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

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

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  • IPEN-DOC 26969

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

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

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  • IPEN-DOC 26968

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

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

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  • IPEN-DOC 26966

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

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

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  • IPEN-DOC 26965

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

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

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  • IPEN-DOC 26964

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

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

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  • IPEN-DOC 26963

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

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

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  • IPEN-DOC 26962

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

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

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  • IPEN-DOC 26960

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

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

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  • IPEN-DOC 26959

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

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

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  • IPEN-DOC 26958

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

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

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  • IPEN-DOC 26957

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

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

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  • IPEN-DOC 26956

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

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

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  • IPEN-DOC 26955

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

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

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  • IPEN-DOC 26952

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

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

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  • IPEN-DOC 26950

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

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

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  • IPEN-DOC 26949

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

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

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  • IPEN-DOC 26943

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

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

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  • IPEN-DOC 26895

    GIANNONI, JULIANA A.; FIORINI, ADRIANA M.R.; IMAMURA, KELY B.; ALCANTARA, ADRIELI de O.; CAMPOS, FABIANI K. de; BISPO, SUZANA do R.; SÁ, ANA P.N. de . Kit de sopa de vegetais minimamente processados direcionados à classe infantil. In: SIMPÓSIO LATINO AMERICANO DE CIÊNCIA DE ALIMENTOS, 12th, November 4-7, 2017, Campinas, SP. Abstract... Campinas, SP: Galoá, 2017.

    Abstract: Desde a infância cada indivíduo já apresenta suas preferências alimentares, estas, nesta fase existe uma grande preferência por alimentos mais calóricos com quantidades elevadas de carboidratos, açúcar, gordura, sal, e baixo consumo de alimentos como vegetais e frutas. O objetivo do Kit de sopa de vegetais minimamente processados em formatos infantis teve como intuito despertar a curiosidade das crianças a consumi-los; bem como avaliar sua composição centesimal, segurança microbiológica e aceitabilidade infantil. Os vegetais escolhidos para montar o kit foram batata inglesa, cenoura e mandioquinha-salsa, os mesmos foram transportados para o Laboratório de Processamento da FATEC/Marília/SP, onde foi realizado o processamento mínimo. O kit foi acondicionado em sacos plásticos a vácuo e mantidos a 5°C por 8 dias. As análises microbiológicas foram efetuadas no primeiro dia do processamento mínimo, a composição centesimal foi avaliada no oitavo dia de armazenamento. Realizou-se a análise sensorial com 107 crianças entre 6 a 8 anos em uma Escola Municipal de Ensino Fundamental da cidade de Vera Cruz/SP. A partir dos resultados obtidos, verificou-se que o kit de vegetais minimamente processados apresentou qualidade nutricional, ausência de salmonella spp. e coliformes termotolerantes dentro dos limites permitidos pela legislação vigente. Foi constatado que a sopa elaborada com o Kit de vegetais em formatos lúdicos, obteve aceitação de 94,39% pelas crianças, demonstrando ser uma alternativa de alimentação saudável e ao mesmo tempo divertida. A vida útil do kit foi de 8 dias sob refrigeração à 5ºC.

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  • IPEN-DOC 26894

    NEGRAO, BIANCA ; VILLAVICENCIO, ANNA L.C.H. . Use of medium and high doses of ionizing radiation in cassava starch. In: SIMPÓSIO LATINO AMERICANO DE CIÊNCIA DE ALIMENTOS, 12th, November 4-7, 2017, Campinas, SP. Abstract... Campinas, SP: Galoá, 2017.

    Abstract: Cassava starch is susceptible to microbial changes, which can affect its shelf life. Ionizing radiation is used in doses sufficient to reduce microorganisms. However, when being exposed to starch granule it can cause changes in structure when compared to other methods. The aim of the work was to irradiate starches with medium and high doses in order to observe the effects on color of cassava starch and texture of tapioca. The starch samples were purchased in supermarkets in two types: starches with preservative (Fc – sodium metabisulphite) and starch without preservative (Fs). They were then irradiated at doses of 0, 5, 10 and 15 kGy in a 60Co Gamma cell 220 with dose rate of 0.764kGy/h-1. Subsequently, the samples were evaluated on 1st, 15th and 30th day after irradiation. The results show that in relation to the tonality (h°) there was a significant difference (P> 0.05) between the control and the irradiated samples on the 30th day. It's worth mentioning that, Fc and Fs had similar behavior at dose of 10 kGy, showing averages nearly h= 90º (Fs: 90.6±0,4; 90.0±0,3; 90.4±0,50 and Fc: 90.5±0,3; 89.9±1,6; 89,5±2,9 on the 1st, 15th and 30th day, respectively) indicating that the samples turned yellowed according to storage days. This tendency towards the yellow color can be attributed to the modification of reactions of the starch monosaccharide’s. The radiation can influence the rupture of surface the starch. For this reason, the tapioca showed increase in hardness (N) according to the increase of radiation dose as well as with storage days. However, on the 30th day, Fc showed no significant difference between doses of 5kGy (10.06); 10kGy (11.44) and 15kGy (11.67). The analysis of the results allows concluding that in this product it's possible use doses up to 10kGy because not change considerably the parameters studied.

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  • IPEN-DOC 26893

    SÁ, ANA P.N. de ; VILLAVICENCIO, ANNA L.C.H. . Características do efeito da radiação ionizante em farofas de carne seca e “bacon”. In: SIMPÓSIO LATINO AMERICANO DE CIÊNCIA DE ALIMENTOS, 12th, November 4-7, 2017, Campinas, SP. Abstract... Campinas, SP: Galoá, 2017.

    Abstract: A farofa está presente diariamente nas refeições dos brasileiros. A irradiação é utilizada pela indústria alimentícia. Avaliamos os efeitos da radiação ionizante em farofa de bacon (FB) e carne seca (FC) nas características de cor e atividade de água. As amostras obtidas no comercio de São Paulo foram irradiadas no acelerador de elétrons no Centro de Tecnologia das Radiações do IPEN/CNEN-SP com doses de 0; 1; 5 e 10 kGy. A cor foi realizada no colorímetro Minolta Chroma Meter modelo CR200b digital e a atividade de água (Aw) no aparelho digital Aqualab, modelo 4TE Duo (Decagon Devices Inc.). As análises foram processadas em temperatura de 25°C±1. Análise de variância (ANOVA) e teste de Tukey com 5% de significância foram aplicados. Observamos no dia 1 de armazenamento a coloração amarelada que se intensificou no decorrer do experimento em todas as doses aplicadas em FB e a FC apresentou diferença significativa na dose de 5kGy. No dia 15, para as duas farofas houve uma diminuição significativa do Croma (C*) para todas as doses e houve uma alteração significativa do tom avermelhado (a*) para as FC. No dia 30, para as duas farofas foi encontrada uma diferença significativa no parâmetro a* das doses de 1 e 5kGy em relação ao controle. Não houve diferença significativa entre 1 e 10kGy. Autores apresentam dados relacionados a farinhas e não a farofas. Os resultados relacionado a Aw de FB mostraram que não houve diferença significativa nas amostras de 1 e 15 dias, porém em 30 dias, as diferenças são significativas. Nas FC foram observadas diferenças significativas em todo o experimento., confirmando a hipótese que a Aw está relacionada com a maioria das reações de degradação de natureza química, enzimática e física. Concluímos que a radiação em doses altas promove alterações em relação ao tempo de armazenamento.

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  • IPEN-DOC 26861

    ROSSI, WAGNER de ; VIEIRA, ALEXANDRE. Texturisation of engine components with shaped ultrashort laser pulses. In: INTERNATIONAL CONGRESS ON LASER ADVANCED MATERIALS PROCESSING, 8th; INTERNATIONAL SYMPOSIUM ON LASER PRECISION MICROFABRICATION, 20th; INTERNATIONAL SYMPOSIUM ON HIGH POWER LASER PROCESSING, 8th, May 21-24, 2019, Hiroshima, Japan. Abstract... Osaka, Japan: Japan Laser Processing Society, 2019.

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  • IPEN-DOC 26848

    MADI, LILIAN ; SORDI, GIAN-MARIA ; ARAUJO, EDMIR. Nuclear state liability for damage resulting from nuclear activities. In: JAKSIC, ALEKSANDAR (Ed.); KARAMARKOVIC, JUGOSLAV (Ed.) INTERNATIONAL CONFERENCE ON RADIATION APPLICATIONS, September 16-19, 2019, Belgrade, Serbia. Abstract... Niš, Serbia: Sievert Association, 2019. p. 91-91.

    Abstract: Nowadays much is discussed about issues related to the preservation of the environment, what can be done to improve it, what should be avoided. In this discussion comes the question of the potential of nuclear energy. One of them is the potential for electric power generation, more cheaply and with less impact to the environment. However, much has already been seen in the world as regards damages that may result from an accident in these plants. In the event of an accident that causes effective damage, either to the environment or to the population, both the Brazilian and foreign standards as predict liability for remedying. The Brazilian Federal Constitution of 1988 determines the competence of the Union to operate nuclear services and installations, being State monopoly activities related to nuclear material and its derivatives. Besides that, CF/88 attributed liability strictu senso for nuclear damage. The Vienna Convention on Civil Liability for nuclear damage, dated May 21, 1993, which was promulgated in Brazil by Decree No. 911/1993, provides that the operator is responsible for nuclear damages, in the case of Brazil, the operator is the State entity (Federal Autarchy) responsible for the operation. Thus, in cases of nuclear damage the State should be held liable objectively. And here issues begin to arise such as: Is the State always responsible? Is there any possibility of exclusion the State liability? This paper aims to analyze the constitutional text and the infra-constitutional rules, correlating the nuclear and environmental legislation to respond to these and other questions.

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  • IPEN-DOC 26847

    COSTA, PRISCILA ; RAELE, MARCUS P. ; DOMIENIKAN, CLAUDIO ; COSTA, FABIO E. ; MADI FILHO, TUFIC ; ZAHN, GUILHERME S. ; GENEZINI, FREDERICO A. . A compact electronic system for a photodiode neutron detector. In: JAKSIC, ALEKSANDAR (Ed.); KARAMARKOVIC, JUGOSLAV (Ed.) INTERNATIONAL CONFERENCE ON RADIATION APPLICATIONS, September 16-19, 2019, Belgrade, Serbia. Abstract... Niš, Serbia: Sievert Association, 2019. p. 36-36.

    Abstract: The demand for portable neutron detectors is on the rise, and for that purpose, low cost boron-10 has been frequently used instead of helium-3, which is usually employed in large and expensive detectors. Portable detectors are of interest in some applications, such as neutron dosimeters or inspection systems targeted in the detection of fissile material and drugs in airports. In this work a portable thermal neutron detection system was developed which is based on a commercial silicon photodiode coupled to a boron converter; this prototype is then plugged into a portable electronic system. The boron layer was produced by pulsed laser deposition, either on a thin glass slide or on the photodiode itself. The boron deposition in the photodiode was made directly in the active area of the detector, so before and after the deposition process a characterization of the device regarding both the dark current and the operation voltage was performed using an americium source. Finally, both configurations were tested. The neutron detection process occurs by detecting the alpha and lithium particles produced by the interaction of the incoming neutron with the boron-10 nuclides. These heavy ions then interact with the active area of the reverse-biased photodiode, producing an electric signal that has to be preamplified and then properly amplified by the portable electronic system, which in turn produces an output that can either be sent to a multichannel analyzer or to a digital counter. The integrated circuit of the low noise preamplifier transforms the detector’s current pulse into a voltage pulse with amplitude proportional to the charge carried by the current pulse. The shaper-driver consists of a differentiator and an integrator and is responsible for filtering and further amplifying the preamplifier signal, generating a NIM-compatible energy output pulse. The performance of the photodiode-amplifier set for alpha particles was successively tested using a 243Am radioactive source. Initial tests were made using the boron-deposited glass, and the electronic signal was properly read. However, when the same system was tested using the boron deposited directly in the photodiode, the output signal couldn’t be read, due to the fact that during the deposition process there was an increase in the dark current and a decrease in the operation bias. In this way, a new portable electronic system was developed using a hybrid integrated amplifier circuit. This new electronic setup allowed the use of both configurations, and was tested both with alpha-emitting Americium and neutron-emitting AmBe sources. In conclusion, both portable electronic systems have proven suitable for the thermal neutron detector developed.

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  • IPEN-DOC 26846

    PEREIRA, MARIA da C.C. ; MADI FILHO, TUFIC ; BERRETTA, JOSE R. ; TOMAZ, LUCAS F. ; MADI, MIRIAM N. . Optical properties and radiation response of Li ion-doped CsI scintillator crystal. In: JAKSIC, ALEKSANDAR (Ed.); KARAMARKOVIC, JUGOSLAV (Ed.) INTERNATIONAL CONFERENCE ON RADIATION APPLICATIONS, September 16-19, 2019, Belgrade, Serbia. Abstract... Niš, Serbia: Sievert Association, 2019. p. 15-15.

    Abstract: Scintillators are materials that convert the energy of ionizing radiation into a flash of light. Due to the existence of different types of scintillators themselves, they were classified into three groups according to their physicochemical characteristics, namely, inorganic, organic and gaseous scintillators. Among the inorganic crystals, the most used as scintillator are constituted of alkali metals, in particular alkaline iodides. Scintillation materials are used in many applications, such as medical imaging, security, physics, biology, non-destructive inspection and medicine. In this work, lithium doped CsI scintillator crystals were grown using the vertical Bridgman technique. The concentration of the lithium doping element (Li) studied was 10-4 M to 10-1 M. Analyses were carried out to evaluate the scintillators developed concerning to luminescence emission and optical transmittance. The luminescence emission spectra of these crystals were measured with a monochromator for gamma radiation from 137Cs source excitation. The optical transmittance measurements were made in the CsI;Li crystal, in a spectral region of 200 nm to 1100 nm. Determination of the dopant distribution along the crystalline axis, allowing to identify the region with Li concentration uniformity, which is the region of the crystalline volume indicated for use as radiation detector. The crystals were excited with neutron radiation from AmBe source, with energy range of 1 MeV to 12 MeV. As with neutron sources also generate gamma radiation, which can interfere with the measurement, it is necessary that detector be able to discriminate the presence of such radiation. Accordingly, experiments were performed using gamma radiation in the energy range 59 keV to 1333 keV in order to verify the ability of the detector to discriminate the presence of different types of radiation.

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  • IPEN-DOC 26845

    MADI FILHO, TUFIC ; PEREIRA, MARIA da C.C. ; BERRETTA, JOSE R. ; TOMAZ, LUCAS F. ; MADI, MIRIAM N. . Study and development of neutron detectors using doped CsI crystals. In: JAKSIC, ALEKSANDAR (Ed.); KARAMARKOVIC, JUGOSLAV (Ed.) INTERNATIONAL CONFERENCE ON RADIATION APPLICATIONS, September 16-19, 2019, Belgrade, Serbia. Abstract... Niš, Serbia: Sievert Association, 2019. p. 14-14.

    Abstract: In the development of nuclear radiation detectors one must take into consideration the process of interaction of the radiation under study with matter. In the case of neutron detectors it must be considered that the detection of neutrons is not trivial in view of the lack of charges of these particles and the peculiarity of their interactions with matter. Another difficulty in the detection of neutrons consists in the discrimination of the electronic impulses generated by the neutrons of those generated by other radiations, almost always present. The main propositions of neutron-sensitive detectors consist of gaseous detectors, scintillators and semiconductors. These detectors intrinsically are not sensitive to neutrons, so they need a radiation converter based on nuclear reactions of the type: Neutron + Converter -> Detectable radiation. Some reactions with neutrons are more used, such as: 10B (n, α), 6Li (n, α) and 3He (n, p). Neutron-scintillation crystal are being the object of active research in several research centers and having their implementations in several applications. The development of new radiation detectors using scintillation crystals, which increases response speed, dose and energy accuracy and, at the same time, the feasibility of simplifying and reducing costs in the production process is always necessary. In the CTR-IPEN laboratory, pure and doped CsI crystals were grown using the Bridgman technique. This work shows the obtained results using doped CsI scintillator with the converters: Br, Pb, Tl, Li as neutron detectors.

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  • IPEN-DOC 26844

    RODRIGUES, ANTONIO C.I. ; MADI FILHO, TUFIC ; SILVA, DAVILSON G. da . Core modeling of the research reactor IEA-R1 with the MCNP-6.2 computational code. In: JAKSIC, ALEKSANDAR (Ed.); KARAMARKOVIC, JUGOSLAV (Ed.) INTERNATIONAL CONFERENCE ON RADIATION APPLICATIONS, September 16-19, 2019, Belgrade, Serbia. Abstract... Niš, Serbia: Sievert Association, 2019. p. 13-13.

    Abstract: The objective of this work is to develop the modeling of the IEA-R1 reactor core with the MCNP-6.2 computational code that was recently acquired. The main advantage of this new version of the code is the performance of burnup calculations of the fuel elements. This modeling will be valid by comparing the thermal and epithermal neutron flux obtained in the calculations with the MCNP-6.2 and the fluxes measured with the activation of gold foils (Au) with and without cadmium coating (Cd) in the same positions of irradiation and, with the same arrangement of fuel elements in the reactor core. After the validation of this model, the idea is to use it for the burnup calculations of the fuel elements that are fundamental for a correct management of the reactor core. Currently, the management of the core is carried out by deterministic codes that are very old and have many approximations leading to very conservative results, for example, TWODB, HAMMER, and CITATION.

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  • IPEN-DOC 26843

    VICENTE, MARCOS A.A.H.; MUNHOZ JUNIOR, ANTONIO H.; MIRANDA, LEILA F. de; SARMENTO, BRUNO F.C.C.; BERNUSSI, AYRTON; OLIVEIRA, RENE ; RIBEIRO, ROBERTO R.; MORAES, DENISON A.. Use of pseudoboehmite for drug delivery system of simvastatin. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 687-688.

    Abstract: Simvastatin is a well known anti-cholesterol drug that is commercially available in Brazil in various strengths including Simvastatin Tablets, with 10, 20 and 40 mg. Simvastatin is a drug, which is used for treating patients with hypercholesterolemia, in order to prevent atherosclerosis, cardiovascular disease, and stroke1. Today cardiovascular disease is still the leading cause of death worldwide. It should also be noted that the treatment of cardiovascular diseases was responsible for just over a third of what the Brazilian federal government disbursed between the years 2013 and 2016 in the purchase of medicines for the population. However, the side effects of simvastatin include muscle pain and liver problems. When diet and exercise are not enough to reduce cholesterol levels, drugs as simvastatin are the medication prescribed. One problem of simvastatin is the low solubility. Simvastatin is practically insoluble in water (30 μg/mL), and 0.1 M HCl (60 μg/mL) [1,2,3]. This paper presents pseudoboehmite nanoparticles synthesized via sol-gel process. The pseudoboehmite were synthesized by an ethanol/water sol–gel method using aluminum nitrate as precursos and sodium hydroxide. The pseudoboehmite with simvastatin entrapped was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) using secondary electrons detector and EDS detector, thermal analysis (thermogravimetric analysis and differential thermal analysis) and Fourier transform infrared spectrometer (FTIR). The data shows that the simvastatin was incorporated homogenously in the pseudoboehmite. The Fourier transform infrared analysis shows that there was no degradation of the drug.

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  • IPEN-DOC 26842

    PIERETTI, EURICO F. ; NEVES, MAURICIO M. das ; CORREA, OLANDIR V. ; ANTUNES, R.A.. Tribological evaluation of CoCrMo alloy for biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1836-1836.

    Abstract: The tribological behavior of the CoCrMo alloy was evaluated in the air in a nanotribometer. The chemical composition, microstructure and mechanical properties of CoCrMo alloys makes them potential materials for use as implantable medical or dental devices [1]. This work has a specific focus on covering the possible in vitro wear modes seen on metal-on metal surfaces. Ballcratering wear test was carried out for 10 min with a solid sphere of WC as counterbody, at a frequency of 75 rpm [2]. The CoCrMo samples’ citotoxicity was analyzed in order to determine if the alloy casting process and its surface finishing, current used in industry, affects the biomaterial’s biocompatibility. All tested surfaces were prepared according to the recommendations for clinical use. The results address the potential detrimental effects of hard particles in vivo such as increased wear rates (debris generation), which is greatly influenced by the normal force, and corrosion (metal-ion release). None sample was considered cytotoxic.

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  • IPEN-DOC 26841

    VIVEIROS, BARBARA V.G. de ; BERBEL, LARISSA O. ; BUGARIN, ALINE F.S. ; DONATUS, UYIME ; COSTA, ISOLDA . The corrosion resistance between AA2050-T84 and AA7050-T7451 welded by friction stir weld. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2089-2089.

    Abstract: Aluminum alloys of the 2XXX and 7XXX series are among the most used materials in the aerospace industry. These alloys have good mechanical, specific strength and corrosion resistance, and for the 2XXX series, further reduction in density can be achieved by lithium addition. So, in this case, it can reduce the weight of the aeroplane and fuel usage leading to the minimization of CO 2 emissions and cost savings. Aluminum alloys have poor weldability, and to use these alloys for aeroplane structures, joining is unavoidable. To make this, the industry uses rivets to join these alloys. But rivets increase the mass of aeroplanes, and to minimise this, a non-fusion (unconventional) welding technique capable of welding aluminium alloys easily was developed. This new technique is friction stir welding, which exposes the aluminum alloys to thermomechanical effects, changing the microstructure of the alloys, and resulting in different regions with different metallurgical and mechanical properties. An example of the regions is the thermomechanically affected region which experiences both plastic deformation and high temperature but without recrystallization. There is also the stir zone which is the region of recrystallized grains, the heat affected zone and the base metal (that is not affected by the welding process). The goals of this work are to analyze the corrosion resistance of the friction stir weldment of dissimilar AA2050-T84 and AA7050-T7451 alloys using electrochemical tests, characterizing the different regions of the weldment, and establishing the most susceptible region to corrosion using a sodium chloride solution.

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  • IPEN-DOC 26840

    QUEIROZ, CARLOS A. da S. . Synthesis and characterization of praseodymium acetate for use in nanotechnology. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2554-2555.

    Abstract: A simple and economical chemical process to obtaining praseodymium acetate of high purity is studied. The raw material in the form of mixed rare earths carbonate comes from an industrial separation of rare earths, thorium and uranium in the Brazilian monazite. It is used the technique of strong cationic exchange resin, proper to water treatment, to the praseodymium's fractionation and it is achieved a purity of 99.9% in Pr6O11 and yield greater than or equal 80%, with the elution by EDTA solution in pH controlled. The complex of EDTApraseodymium is transformed in praseodymium oxide, subsequently the oxide is dissolved in acetic acid to obtain the praseodymium acetate. The solid salt was characterized via chemical analysis, thermal analysis, X ray diffraction and infrared spectroscopy. In summary the analytical data collected allowed to conclude that stoichiometric formula for the praseodymium acetate obtained is Pr(CH3COO)3.1.5H2O. The molecular absorption spectrophotometry technique is used to monitoring the praseodymium content during the process and mass spectrometry to certification the purity of the praseodymium acetate. The typical praseodymium acetate contain the followings contaminants in micrograms per gram: Y( 20 ), Sc ( 18 ), La ( 6 ), Ce ( 26 ), Nd ( 3 ), Sm ( 18 ), Eu ( 17 ), Gd (19 ), Tb ( 16 ), Dy (17 ), Ho ( 18 ), Er (18 ), Tm ( 16 ),Yb ( 17 ), Lu ( 17.0), Lu ( 17 ).

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  • IPEN-DOC 26839

    RIBEIRO, ELOANA P. ; FARNEZE, STELLA K. ; COUTO, ANTONIO A. . Shot peening surface treatment effect in 316L stainless steel surface modification. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 216-216.

    Abstract: Stainless steel 316L (low carbon) is the most widely used steel as biomaterial. This metal has low toughness, so metallic implants are prone to wear [1]. Residual compressive stress and surface toughness increase can improve materials life fatigue, as a tough layer prevents plastic deformation. Materials failure, as fatigue and wear, are related to materials surface properties and structure [1]. Shot peening is a mechanical surface treatment in which many small spheres are accelerated and blasted in materials surface to promote impacts with sufficient energy to generate plastic deformation. The main aim of this technique is to induce residual compressive stress on materials surface, increasing wear properties and toughness. Surgical implants are submitted to this treatment to generate surface roughness increase for better adhesion too [2]. In this work, shot peening was performed using four different conditions to verify the effect on surface modification. Microscope techniques, x-ray diffraction, residual stress, toughness and roughness measurements were used to validate the tests. In conclusion, shot peening is an effective surface treatment to induce residual stress and increase roughness and toughness in 316L stainless steel.

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  • IPEN-DOC 26838

    RIBEIRO, E.P. ; FARNEZE, S.K. ; COUTO, A.A. . Shot peening effect in F138 stainless steel surface modification. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Resumo expandido... São Carlos, SP: Aptor Software, 2019. p. 2632-2634.

    Abstract: Stainless steel F138 is the most widely used steel as biomaterial. This metal has low toughness, so metallic implants are prone to wear [1]. Residual compressive stress and surface toughness increase can improve materials life fatigue. Shot peening is a mechanical surface treatment in which many small spheres are accelerated and blasted in materials surface, inducing residual compressive stress on materials surface. Surgical implants are submitted to this treatment to generate surface roughness increase for better adhesion too [2]. In this work, shot peening was performed using four different conditions to verify the effect on surface modification. Microscope techniques, x-ray diffraction, residual stress, toughness and roughness measurements were used to validate the tests. In conclusion, shot peening is an effective surface treatment to induce residual stress and increase roughness and toughness. Keywords: F138, Residual Stress, Shot Peening, Stainless Steel.

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  • IPEN-DOC 26837

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L. ; BRANDÃO, JAQUELINE de S.; PFEIFER, JOÃO P.H.; ROSA, GUSTAVO dos S.; KRIECK, ANDRE M.T.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Preparation of porous ternary alloy Ti-34-Nb-6Sn / Mg for the implant. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1042-1042.

    Abstract: Titanium alloys are designed in order to provide attractive mechanical properties, including Young's modulus, high mechanical strength and biocompatibility [1]. These properties are achieved when titanium structured under β phase, and the selection of non-toxic beta-stabilizing metals is important for the improvement of the alloys. In order to create a good interaction at the bone-implant interface, it is interesting that these biomaterials also have adequate porosities for the bone cells to adhere on its surface, and the bone tissue to grow around the prosthesis. Thus, the purpose of this work was to produce the Ti-34-Nb-6Sn alloy by the powder metallurgy technique allied to the magnesium space holder. After the synthesis, the structure of the material was characterized by X-ray diffractometry (XRD) and its morphological and compositional analysis, carried out by Scanning Electron Microscopy (SEM) and X-ray dispersive energy (EDX). The apparent porosity analysis was made by the Archimedes method. In the biological assay, stem cells derived from equine bone marrow were seeded on the surface of the materials in order to obtain information about cytotoxicity and cell adhesion. The results of XRD and MEV confirmed the formation of the alloy (PDF: 25-977), being that the proportion of phase β was greater than the phase α (PDF: 44-1288,41-1352), and the evaporation of Mg, as well as a significant increase of porosity, which was also confirmed by the Archimedes method. Additionally, according to SEM, the cells showed good adhesion on the surface of the material, as well as inside the formed pores. According to the techniques used, it was then possible to obtain β phase rich titanium alloy with significant porosity on which the cells adhered satisfactorily.

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  • IPEN-DOC 26836

    BOTTA, WALTER J.; LEAL NETO, RICARDO M. ; JORGE JUNIOR, ALBERTO M.; ZEPON, GUILHERME; ISHIKAWA, TOMAZ T.; BOLFARINI, CLAUDEMIRO; KIMINAMI, CLAUDIO S.; LEIVA, DANIEL R.. Mg-based composites for hydrogen storage. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 47-48.

    Abstract: Magnesium hydride can be already considered as the traditional hydrogen storage material despite some unanswered fundamental questions concerning its properties. These questions concern the understanding of the activation (or first hydrogen absorption) step, the role of the additives in the absorption / desorption kinetics and the synergy between phases in the absorption / desorption kinetics, in the case of composites systems. Recent results indicated that modifications of conventional processing routes to synthesize hydride-forming systems might have a strong role in the hydrogen storage behavior of different metals and compounds. The present work shows results of Mg-TiFe and Mg-LaNi5 composites that have been produced by new approaches of the usual techniques, such as high-energy ball milling (HEBM) and cold rolling (CR) under inert atmosphere. Structural characterization was carried out by X-ray diffraction (XRD) and scanning and transmission electron microscopy (SEM and TEM). H-absorption / desorption kinetics were measured in a Sievert’stype apparatus and by differential scanning calorimetry (DSC) coupled with thermogravimetric analysis (TGA) and mass spectrometry (QMS). MgH2 hydride was formed at room temperature in Mg-TiFe composites produced by HEBM, in this case with an important improvement in the hydrogen absorption kinetic as compared with pure Mg. MgH2-LaNi5 composites were prepared by cold rolling under an inert atmosphere and the composite presented faster hydrogen absorption/desorption kinetics and reduced desorption temperatures in comparison to MgH2. These results are discussed in view of the above fundamental questions, in particular considering the possible synergy between Mg and the second phase (TiFe or LaNi5) in the modification of absorption and desorption kinetics.

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  • IPEN-DOC 26835

    LAZARIN JUNIOR, ELOI; MUNHOZ JUNIOR, ANTONIO H.; MIRANDA, LEILA F. de; SARMENTO, BRUNO F.C.C.; BERNUSSI, AYRTON; LIMA, NELSON B. de ; ROSSI, MAURA V.; PERES, RENATO M.; FLORENCIO, ODILA. Metformin release with pseudoboehmite. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 955-956.

    Abstract: Diabetes Mellitus is a chronic disease in which high levels of blood glucose are found. It arises when the pancreas does not produce enough insulin, a hormone that regulates blood sugar concentration. It also occurs when the body does not properly use the insulin it produces. There are two main forms of diabetes: type 1 diabetes, the treatment of which is insulin injections, and type 2 diabetes, where the body's cells do not respond to insulin properly. In Brazil the diseases that most affect the population are diabetes, hypertension and stroke. The number of Brazilians diagnosed with diabetes has grown 61.8% in the last 10 years. In 2006, 5.5% of the population had the disease and in 2016 8.9% [1]. It has also been observed in Brazil that diabetes increases with age and is almost three times higher among those with lower schooling. People between the ages of 18 and 24 have a rate of 0.9%, between 35 and 44 years old, the rate is 5.2%, and among people aged 55-64 years, the number reaches 19.6%. The largest registry, however, is in the population aged 65 years or older, which presents an index of 27.2%. In recent years, several papers reported the use of pseudoboehmite for use in controlled drug delivery systems. The drugs tested include atenolol [2], Glucantime® [3], acyclovir [4] and DOX, a typical chemotherapeutic anticancer drug [5]. In this research pseudoboehmite was produced by sol-gel process and metformin was incorporated in the gel of pseudoboehmite. After that the gel was vacuum filtered and dried to obtain a powder by freeze-drying. The dry powder was characterized by x-ray diffraction, thermal analysis (Thermogravimetric analysis and differential thermal analysis), nitrogen adsorption isotherm, specific surface area by B.E.T. method and scanning electron microscopy using secondary electron detector and EDS detector. The results shows that the drug was homogeneously incorporated in the pseudoboehmite.

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  • IPEN-DOC 26834

    ANDRADE, ARNALDO H.P. de ; LOBO, RAQUEL de M. ; BREDA, FRANCISCO J. ; CASTAGNET, MARIANO . Mechanical anisotropy of ABS specimens 3D printed by FDM. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2564-2564.

    Abstract: Additive manufacturing (AM) has been developed as a technique for fast fabrication of component parts through 3D printing, using a process of adding successive layers, one after another. The Fused Deposition Modeling (FDM) technique is a 3D printing process that generally uses a thermoplastic filament as the printing base material. The material is fed by a coil and the head of the extruder performing the process is heated. Printing can be done in several directions, depending on the purpose of the component part. In this work mechanical tests were done on ABS (Acrylonitrile-Butadiene-Styrene) tensile specimens built by FDM, in different orientations, to analyze its properties and to make a correlation between these properties and the influence of the printing direction in the final product. The tensile specimens in dog bone shaped were tested according to the ASTM D638 standards. The experiments were done at room temperature. The horizontal built specimens (H-specimens), fabricated in the z-direction, while the beads were layered along the x and y direction, parallel to the build table, showed the maximum resistance of 30 MPa. The specimens built with their gage length out of x-y plane (V-specimen and D-specimen, vertical and diagonal specimens respectively) presented lower ultimate strength, for instance 14 MPa for the Vspecimen. Additional investigation is on the way to understand the presence of defects (cavities and crazes) in the ABS microstructure since the literature points that the ability to manipulate it is the key to an improved performance of this type of structural material.

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  • IPEN-DOC 26833

    LEAL NETO, RICARDO M. ; VEGA, LUIS E.R.; FALCÃO, RAILSON B. ; LEIVA, DANIEL R.; ROCHA, CLAUDIO J. ; ISHIKAWA, TOMAZ T.; KIMINAMI, CLAUDIO S.; BOTTA, WALTER J.. Mechanical activation of TiFe for hydrogen storage: ball milling x cold rolling. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 49-50.

    Abstract: The aim of this work is to report some recent developments on the synthesis of TiFe by high energy ball milling and cold rolling, concerning hydrogen storage. Ball-milled TiFe was produced by two procedures, both under inert atmosphere and with various milling times. In the first one a powder mixture of TiH2 an Fe was milled, followed by a vacuum heat treatment to promote the reaction synthesis of TiFe compound [1]. Second procedure consisted of milling Ti and Fe powders with stearic acid (as a process control agent) after a pre-milling operation (with the same powders and without PCA) to prepare the surface of milling media. Both methods were conceived for avoiding strong adherence of the powders to the milling balls and vial, impairing the mechanical alloying. Cold rolling was performed on a ground TiFe ingot produced by arc melting [2]. After 20 to 40 passes under inert atmosphere, powder particles and thin cracked flakes were produced. Results showed that both milling procedures succeeded in avoiding unacceptable adherence to the milling media, with high loose powder yields. Whatever the route, nanostructured TiFe was obtained with no need of further thermal activation for the first hydrogenation. Hydrogen absorption capacities of about 1.0 wt% at room temperature was obtained with both milling procedures. Higher capacity (1.4wt%) was obtained with cold rolled TiFe (powder and flakes) after 40 passes. Some possible explanations for this difference are presented and discussed.

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  • IPEN-DOC 26832

    PIERETTI, EURICO F. ; NEVES, MAURICIO M. das . Magnetic susceptibility of a laser treated biomaterial. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2024-2024.

    Abstract: Austenitic stainless steel ISO 5832-1 is widely used as biomaterial due to its mechanical properties, chemical composition, degradation resistance and low cost. In this work, we evaluated the magnetic susceptibility of samples of this biomaterial, with laser texturing surface treatment in four different pulse frequencies, as well as samples without laser treatment, for comparison purposes. Relative magnetic permeability (μr) measurements were performed on a magnetic susceptibility scale. A Bruker magnetic force microscope (MFM), model SPM Multimode 8, with analysis processing software Nanoscope Analysis, was used in the Tapping Mode operation to perform naturally generated magnetic field measurements on the laser textured samples surfaces. The treatments affected the magnetic susceptibility of these surfaces, which was higher for the textured samples when compared to the other surface finishing conditions, which is undesirable for a biomaterial. The magnetic field evaluations by MFM are of qualitative character. Qualitatively distinct images of amplitude and phase difference signals were noted. This fact proved the results obtained by the technique of measurement of magnetic signals by precision scale. The analysis of the images obtained by MFM suggested that the parameters variation for laser texturing resulted in variation of intensities and distribution of magnetic field signals on this biomaterial’s surfaces.

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  • IPEN-DOC 26831

    BUGARIN, ALINE F.S. ; TERADA, MAYSA ; POLITANO, RODOLFO ; COSTA, ISOLDA . Investigation of the evolution and influence of hardening phases on the corrosive behavior of AA2198. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2120-2120.

    Abstract: The Al-Li alloys are 2XXX series aluminum alloys and has been gaining space in the aeronautical applications. Adding 1% by weight of Li to aluminum, reducing by 3% at the final density and increasing by an average of 6% in the modulus of elasticity of the material. The characteristics and advantages presented by the Al- Li alloys, together with the growing interest of the aeronautical industry, have resulted in the interest in studying the relationship between the microstructure and its corrosion behavior. Alloy 2198 is a third generation of Al-Li alloys. Alloy elements such as Cu, Li and Mg promote the increase of the mechanical strength of the alloy by solid solution and the precipitation of phases T1 (Al2CuLi), Ɵ '(Al2Cu) or S (Al2LiMg). Phase T1 is the main hardening phase of the material and because it is more electrochemically active, it decreases the corrosion resistance. In this work, the AA2198 as received was solubilized at 500 °C to clear the thermal history of the material. A homogenization treatment was carried out for 1 h and 4 h with mechanical vacuum and an oven with argon controlled atmosphere. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) tests were performed to verify the kinetics and influence of phase precipitations on the mechanical response of the material. The resistance to corrosion of the different homogenization conditions was investigated with electrochemical tests, such as Open Circuit Potential (OCP) and Polarization.

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  • IPEN-DOC 26830

    SANTANA, JESSICA C.C. de C.; SILVA, REJANE M.P. da ; ANTUNES, R.A.; SANTOS, SYDNEY F.. Influence of decarburization on the local corrosion behavior of the SAE 9254 spring steel. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2199-2199.

    Abstract: Decarburization is an unwanted metallurgical phenomenon comprising the loss of carbon from the steel through outward diffusion and oxidation on the surface at high temperatures. As this phenomenon leads to phase transformations in a small region close to the surface, it is likely expecting some effects on the local chemical reactivity of the steel. This, in turn, would account for the appearance of preferential anodic sites that can act as localized corrosion spots. Macroscopic corrosion symptoms, observed by conventional corrosion techniques, express only the final step of a complex and dynamic sequence that begins at the microscopic level. Several localized electrochemical techniques can be used to characterize local corrosion processes. One of them is the scanning electrochemical microscopy (SECM). The aim of the present work was to study the surface chemistry, microstructure and local corrosion processes at the decarburized layer of the SAE 9254 automotive spring steel. The samples were austenitized at 800, 850, 900 and 950 °C followed by oil quenching. The microstructure was investigated using confocal laser scanning microscopy and scanning electron microscopy. The surface chemistry was analyzed by X-ray photoelectron spectroscopy. The local electrochemical activity was probed by SECM. Microstructural characterization and XPS analysis indicate a dependence of the local electrochemical processes with the steel microconstituents and also Si and Cr oxides formed during heat treatments. The presence of the ferritic layer enhanced the multiphase character of the steel microstructure in the region of partial decarburization of sample A900, increasing iron oxidation and, therefore, the local electrochemical activity for this condition.

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  • IPEN-DOC 26829

    LOBO, RAQUEL de M. ; MORCELLI, APARECIDO E.; BREDA, FRANCISCO J. ; CASTAGNET, MARIANO ; ANDRADE, ARNALDO H.P. de . Fracture surface analysis of ABS samples printed by the FDM method. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2567-2567.

    Abstract: FDM (Fused Deposition Modeling) is one of the most used technique in additive manufacturing (AM). It can be summarized as printing small components through a heated thermoplastic filament, which is deposited layer by layer through a 3D printer. The print head can be programmed to perform the job in different directions (X, Y and Z) even with predetermined slopes. In this work, flat tensile specimens were prepared in different directions using an ABS (Acrylonitrile-Butadiene-Styrene) filament with a processing temperature between 210-225 ° C. After tensile tests, the fracture surfaces were analyzed to get a better understanding of the deformation and fracture processes. The crosssection view of specimen´s morphology was examined with a scanning electron microscope at a very low accelerating voltage (1 kV). The specimens were coated with gold using a sputtering system. The specimens that showed the smaller ultimate strength (named V-specimen) presented numerous large cavities in its microstructure suggesting that these voids may have a major contribution to the mechanical performance of the material.The fracture surface also shows a possible pull-out between layers indicating a weak point in the microstructure of the built sample that’s requires further investigation.

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  • IPEN-DOC 26828

    RAMANATHAN, LALGUDI V. ; FERNANDES, STELA M.C. ; CORREA, OLANDIR V. . Effect of mixed nanocrystalline rare earth oxide coatings on high temperature oxidation of a ferritic stainless steel AISI 409. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 414-414.

    Abstract: Rare earths (RE) have been used to improve the high temperature oxidation resistance of chromium dioxide and alumina forming alloys. The RE can be added to the alloy as elements or as oxide to form dispersions. It can also be applied as a RE oxide coating on the surface of the alloy. In this investigation the sol-gel technique was used to prepare sols of the RE oxides as it produces nanocrystalline oxide particles. In an effort to increase further the oxidation resistance of high temperature alloys, optimization of RE oxide additions to the alloy surface was attempted. This paper presents the effect of nanocrystalline oxide gel coatings of CeO2, Nd2O3, Pr2O3, CeO2 + Nd2O3, CeO2 + Pr2O3 and Pr2O3 + Nd2O3 on the oxidation behavior of a ferritic stainless steel AISI 409 at 1000 °C in air using a thermogravimetric balance. The morphology of the pure oxides was studied and the following formats were observed: CeO2 – rods; Nd2O3 – platelets; Pr2O3 – needles; La2O3 – cuboids. The average oxide particle sizes and the average crystallite sizes were also determined. The oxidation rate of the coated steel specimen was significantly less than that of the uncoated steel specimen, due to formation of a fine layer of chromium dioxide at the steel/oxide interface. The oxidation rates of the different REO coated steel specimens varied with the type of REO. The mixed oxide containing Pr2O3 increased significantly the oxidation resistance of the steel. The CeO2 + Nd2O3 mixture did not increase oxidation resistance of the steel further, compared to those with either one of these two rare earth oxides. The differences in the influence of a specific rare earth oxide or a mixture are attributable to differences in the ionic radii of the RE and the morphology as well as the crystallite sizes of the RE oxides.

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  • IPEN-DOC 26827

    AGUIAR, DEIZE B. dos S.; QUEIROZ, FERNANDA M.; VERISSIMO, NATHALIA C.; AYUSSO, VICTOR H. ; PEREIRA, VICTOR F.; FONSECA, EDUARDO B. da; MELO, HERCILIO G. de; COSTA, ISOLDA ; TERADA, MAYSA ; BUGARIN, ALINE F.S. . Effect of Ce on the corrosion resistance of anodized AA2024-T3 FSWed. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2111-2112.

    Abstract: Friction stir welding (FSW) is a solid-state joining technique, which has numerous advantages over conventional fusion techniques, such as automation and reproducibility, environmentally friendly, and capability to weld large thicknesses in a single pass. AA2024 are widely used in the aerospace industry due to their properties as lightweight, high specific strength and durability. However, they are prone to localized corrosion due to its high amount of intermetallics. New anodizing and sealing processes have been studied due to the environmental and health problems related to the sealing treatment containing hexavalent chromium ions. This has encouraged the search for new processes for surface treatment of metals. Recent studies are pointing towards tartaric-sulphuric anodizing, as a viable alternative for the corrosion protection of aluminum alloys, including surface treatments with cerium ions. Other promising method to protect the exposed metal surface is to use eco-friendly alternative corrosion inhibitors in combination with a barrier coating system. Sol–gel coatings have also been extensively studied as potential pre-treatments not associated to toxic residues for aluminum alloys surface preparation prior to paint. It has been demonstrated an efficient alternative for replacement of the chromate technology. In this study, friction stir welded samples were anodized and then sealed in an aqueous solution with the addition of cerium ions at 70 °C. The effect of Ce on the characteristics of the surface film formed, such as morphology and corrosion resistance, was investigated by SEM and electrochemical impedance spectroscopy. Samples unsealed or hydrothermally sealed were also tested for comparison. The EIS results showed that the addition of Ce (III) ions improved the corrosion resistance of the AA 2024-T3 TSA anodized and hydrothermal sealed.

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  • IPEN-DOC 26826

    GIAROLA, JOSEANE M.; PEREIRA, GUALTER S.; KUGELMEIER, CRISTIE L.; TERADA, MAYSA ; MARCOMINI, JOSE B.; ROVERE, CARLOS A.D.; AVILA, JULIAN A.; BOSE FILHO, WALDEK W.. Corrosion behavior of friction stir welded API X70 steel joints. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 2171-2171.

    Abstract: The ever-increasing demand for fossil fuels has pushed the oil and gas industry to search for new deep water wells and in more aggressive environmental conditions, such as the pre salt where the presence of CO2 and H2S concentrations, has led to the development of new materials and manufacturing processes. For pipeline construction, Friction Stir Welding (FSW) process is a promising candidate to be used in the girth welding procedure, and research studies must be carried out to understand the effect of this new processing on the pipeline life under the in-service conditions (environment, fatigue). The present work is part of a research project aiming to investigate the effect of a saline environment on the mechanical properties of an API-5L-X70 steel, welded by FSW. Therefore, in this work, the results of the corrosion behavior analysis carried out on the FSW welded joint, considering a 3.5% NaCl solution, are presented. The corrosion behavior was investigated based on potentiodynamic polarization tests on the different regions of FSW welded joint, i.e., the base metal (BM) and stirred zone (SZ). Gel visualization tests, considering the whole welded joint, were also conducted. The two FSW regions showed similar polarization curves in terms of corrosion potential (Ecorr), corrosion current density (icorr) as well as anodic current density values. In the gel tests, a preferential localized attack on any of the regions of the FSW welded joint was not observed. These results can be interpreted as evidence that the corrosion behavior of the FSW welded joint was not significantly affected by the different metallurgical microstructures formed by the FSW processing.

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  • IPEN-DOC 26561

    SONA FILHO, CELSO R. ; BENTO, RODRIGO T. ; SILVA, CECILIA C.G. e ; PILLIS, MARINA F. . Physical-chemical characterization of Si3N4-TiO2 ceramic nanocomposites obtained to biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1051-1051.

    Abstract: Silicon nitride based ceramics (Si3N4) are very important materials in the engineering and medical fields because of their physical, chemical, tribological and mechanical properties. However, some researchs have been carried out in order to obtain silicon nitride ceramics with improved biological behavior, including studies about the effect of nanoparticles on their bioactivity. In this work, Si3N4-TiO2 nanocomposites were synthesized and characterized by their physical, chemical and bioactive properties. Initially, Si3N4, MgO, SiO2 and CaO powders were mixed in a ball mill for 24 h The mixture was then dried at 100 ºC for 1 h under the nitrogen atmosphere. Subsequently, the samples were coated with TiO2 from the sol-gel process. The precursor solution of titanium dioxide (TiO2 ) was prepared from the mixture of titanium (IV) isopropoxide and isopropanol at a ration of 1:10. The pH of the solution was adjusted to 3 by the addition of sulfuric acid. The precursor solution was dispersed by constant stirring at 50 ºC for 1 h. The samples were immersed for 10 minutes in this solution at room temperature and then dried for 24h under UV light. The samples were calcined at 400 and 500 ºC for 60 min to obtain Si3N4-TiO2 nanocomposites. The microstructure of the materials were anayzed by scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The samples bioactivity was evaluated by in vitro tests using SBF (Simulated Body Fluid) solution at 37 ºC for 9 days of immersion. The nanocomposites showed good quality, high uniformit of coating and greater adhesion to TiO2 to the substrate of Si3N4. The formation of CaP deposits with globular structure on the samples surface during the SBF experiment is a strong indication of the bioactivity of the nanocomposites. The results suggest that Si3N4-TiO2 ceramic nanocomposites have great potential to be used in biomedical applications.

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  • IPEN-DOC 26554

    NERY, JOSE G.; RATERO, DAVI R.; SILVA, DANILO A. da; MARUMO, JULIO T. ; ARAUJO, LEANDRO G. de ; MEDEIROS, VINICIUS L.. Hydrothermal and assisted microwaved syntheses of Stanno and Yttrium metallosilicates as heterogeneous catalyst for biodiesel production and environmental remediation. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 484-484.

    Abstract: This study reports the synthesis, physicochemical characterization by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and solid-state MAS NMR (1H, 23Na, 29Si and 89Y and 119Sn MAS NMR) of a stanno and yttrium metallosilicate and their application as a heterogeneous catalyst for biodiesel production via ethanolysis and methanolysis routes using edible, non-edible an waste oils as feedstocks and environmental remediation. Heterogenous catalytic studies in the transesterification of refined edible, non-edible, and waste oils have resulted in high yields of FAMEs and FAEEs (fatty acid methyl and ethyl esters), nevertheless the highest FAMES (98.2%) and FAEEs (96.6%) yields were obtained for non-edible microalgae oil extracted from the genetically modified heterotrophic algal strain Prototheca moriformis. Catalytic studies also using nonedible macaw palm oil (Acrocomia aculeata) with a high content of free fatty acids (FFAs) demonstrated that the catalyst could simultaneously perform esterification and transesterification reactions using using different sources of lipids feedstocks, notably those that do not compete with food production [1]. On the other hand, Yttrium metallosilicate were very efficient in the separation, binding and chemical stabilization of hazardous inorganic, organic and radioactive species such as lead ( Pb2+, Cd2+, Ba2+ , Cs+ and Sr2+) in aqueous systems.

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  • IPEN-DOC 26543

    SANTOS, EMANUELLA C. dos; BATISTA, BEATRIZ da S.; LIMA, RUANA C.; ALENCAR, LUCIANA M.R.; SANTOS, ADENILSON O. dos; PEDROCHI, FRANCIANA; OTUBO, LARISSA ; LANG, ROSSANO; SILVA, LUZELI M. da. Bioactivity study of Co-Cr alloys doped with tantalum for biomedical applications. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1017-1018.

    Abstract: Co-Cr alloys are well known because of its high wear resistance, mechanical strength and corrosion resistance due to the chromium oxide passive layer formation that protects the material surface [1].The addition of alloying elements, particularly Mo and W, improve the properties of Co-Cr bioalloys, although these materials can still be improved to meet the requirements for a biomaterial.Thus, considering that tantalum is a bioactive metal, it can be an interesting option to improve the biocompatibility properties of these alloys[2].The present study aims the synthesis and in vitro evaluation bioactivity of Co-Cr alloy doped with tantalum.The synthetized alloys were submitted to a surface treatment and subsequentlyimmersed in Simulated Body Fluid (SBF) for 28 days. The samples bioactivity was evaluated by using X- ray Diffraction (DRX), Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy (EDS) and Atomic Force Microscopy (AFM) techniques. X- ray diffraction analysisin the SBF immersed samples shown a small intensity peak characteristicof hydroxyapatite while MEV and EDS results revealeda surface structure with the presence of P, Mg, Ca and Oelements. The grain growth dynamics on the samples surfaces was observed by using AFM measurements.

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  • IPEN-DOC 26533

    BORAZANIAN, TATYANA C.F. ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Influence of the heat treatment on the photodegradation efficiency of the supported TiO2 catalysts obtained by a facile airbrush spray-coating. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1665-1666.

    Abstract: One of the main topics of thin films processing routes based on sol-gel is the need for low-cost and simple techniques [1]. Airbrush spray-coating method has been applied to coat materials, due to its cost-effective, large area and versatile characteristics [2]. However, this technique is not yet sufficiently explored for supported catalysts employed on the water treatment. In this work, titanium dioxide (TiO2) films were successfully deposited on borosilicate substrates by a facile airbrush spray-coating technique, at room temperature, from a solution of titanium (IV) isopropoxide diluted in isopropanol. The angle of the cold spray was fixed in 45°, and the feed rate was 17 mm.s-1. The coated specimens were dried at 100 °C for 60 min, and then heat treated at 300, 450 and 500 °C for 30 min to evaluate the influence of the temperature process on the methyl orange dye degradation under UV light. The catalysts obtained showed a great surface covering, highly porous surface, and good adherence to substrate. The films presented the formation of TiO2-anatase phase. Methyl orange dye degradation experimental results indicated that the TiO2 film heat treated at 500 °C presented a higher photocatalytic behavior, that exhibited 68.3 % of the dye degradation for 300 minutes under UV radiation – around 18.5 % more efficient than the supported catalysts prepared at 300 and 450 °C, with a photocatalytic efficiency of 31.6 % and 57.7 %, respectively. The study of the influence of heat treatment on the photocatalytic activity suggests the existence of an ideal temperature in which the photocatalyst exhibits the better photodegradation performance. The results suggest that the supported TiO2 catalysts deposited by the airbrush spraycoating method have a promising practical application for the green treatment of organic pollutants.

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  • IPEN-DOC 26532

    MARCELLO, BIANCA A. ; CORREA, OLANDIR V. ; BENTO, RODRIGO T. ; PILLIS, MARINA F. . Effect of the thickness of TiO2 films on the photodegration of methyl orange dye. In: BRAZIL MRS MEETING, 18th, September 22-26, 2019, Balneário Camburiú, SC. Abstract... São Carlos, SP: Aptor Software, 2019. p. 1696-1696.

    Abstract: The increase of the disposed of azo dyes such as methyl orange (MO) by textile and allied industries in the wastewater results in a significant increase of pollutants, which requires the development of new degradation materials and techniques to purify the effluents [1]. Heterogeneous photocatalysis using titanium dioxide (TiO2) films is a highly efficient oxidative process for water treatment [2]. The TiO2 films were grown on borosilicate substrates by metalorganic chemical vapor deposition (MOCVD) at 500°C, and the growth time was controlled in order to obtain films with the thickness of 400, 600 1100 and 2100 nm. MO dye degradation was evaluated by using anatase-TiO2 as photocatalyst under UV light. The pH of the solutions was set on 2. The TiO2 films presented uniform thickness and well-defined columnar structure that grow perpendicular to the substrate surface. The increasing of the growth time increases both the thickness and the mean grain size of the films. All the films presented the formation of anatase-TiO2 crystalline phase grown preferentially oriented at (112). The results showed that the photocatalytic behavior of the films decreased with increasing the film thickness. The photocatalytic efficiency for the 400, 600, 1100 and 2100 nm films tested at pH 2 are respectively 39.2%, 30.2 %, 24.4 % and 12.2 %. When the thickness of the films augments, the mobility of the electrons is impaired due to the increase of the film opacity, which limits the light penetration through the catalyst, and difficults the diffusion of charge carriers required to activate the semiconductor surface. TiO2 catalysts grown by MOCVD technique is a practical promising application for the water treatment.

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  • IPEN-DOC 26825

    COUTO, CAMILA P. ; REVILLA, REYNIER; COSTA, ISOLDA ; PANOSSIAN, ZEHBOUR; ROSSI, JESUALDO ; TERRYN, HERMAN; DE GRAEVE, IRIS. Investigation of electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si before and after hot stamping process by means of SKPFM measurements. In: EUROPEAN CORROSION CONGRESS, September 9-13, 2019, Seville, Spain. Abstract... 2019.

    Abstract: The demand for hot stamped components has been growing in structural vehicle applications, due to the advantages of combining lightweight design and safety improvement. Boron-manganese 22MnB5 steel is the most common grade for hot stamping applications. After the thermomechanical process, the steel exhibits up to 1,500 MPa of tensile strength with the absence of the springback effect. The hot stamping process involves heating the steel blank to the austenitization temperature and then transferring it from the furnace to the press tool, where the material is formed and quenched simultaneously. Due to high temperatures during the process, the steel blank is protected with a metallic coating to avoid the steel decarburization and oxidation. Hot-dip Al-Si is the most applied coating system on boron-manganese steel for hot stamping applications. It is known that, during hot stamping, diffusion takes place changing the coating layer morphology. The objective of this study is to investigate the effect of the hot stamping process on the electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si by means of the SKPFM technique. Moreover, the samples were characterized by means of FE-SEM/EDS. The SKPFM results showed that, before the hot stamping process, there is a high difference of potential between the coating layer and the steel substrate. After hot stamping, this difference decreases. In both conditions (before and after hot stamping), the coating layer is less noble than the steel substrate. It was also observed that the steel substrate potential also decreased after the hot stamping process. This could be a consequence of iron diffusion towards the coating layer and the recrystallization of the substrate after the thermo-mechanical process.

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  • IPEN-DOC 26824

    SILVA, REJANE ; MILAGRE, MARIANA ; OLIVEIRA, LEANDRO; ANTUNES, RENATO; DONATUS, UYIME ; COSTA, ISOLDA . Influence of surface finishing on the electrochemical activity of the 2098-T351 aluminum alloy. In: EUROPEAN CORROSION CONGRESS, September 9-13, 2019, Seville, Spain. Abstract... 2019.

    Abstract: In this work, scanning electrochemical microscopy (SECM) measurements were employed to characterize the electrochemical activities of polished and as-received surfaces of the 2098-T351 aluminum alloy (AA2098-T351). The effects of the near surface deformed layer (NSDL) and its removal by polishing on the electrochemical activities of the alloy surface were evaluated and compared by the use of different modes of SECM. Confocal Laser Scanning Microscopy (CLSM) and energy dispersive X-ray spectroscopy (EDS) were also employed to characterize the morphology of the surfaces. The surface chemistry was analyzed by X-ray Photoelectron Spectroscopy (XPS). The generation/tip collection (SG/TC) and competition modes of the SECM were used to study hydrogen gas (H2) evolution and oxygen reduction reactions, respectively. H2 evolution and oxygen reduction were more pronounced on the polished surface compared to the asreceived surface that revealed lower electrochemical activities showing that either the NSDL largely decreased the local electrochemical activities at the AA2098-T351 surface.

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  • IPEN-DOC 26822

    CORREA, B.S. ; COSTA, M.S.; CABRERA-PASCA, G.; SENA, C.; PINTO, R.H.; CARVALHO JUNIOR, R.N.; FREITAS, R.S.; SAIKI, M. ; CORREA, E. ; CARBONARI, A.W. . Can natural oils improve the properties of magnetic nanoparticles?: A systematic study of iron oxide nanoparticles coated with oils from Amazon fruits. In: ANNUAL CONFERENCE ON MAGNETISM AND MAGNETIC MATERIALS, 64th, November 4-8, 2019, Las Vegas, Nevada, USA. Abstract... 2019.

    Abstract: The use of nanoparticles coated with different materials have been studied by many researchers to improve the quality of nanomaterials for biomedical applications such as controlled drug delivery, image contrast and treatment of cancer by magnetic hyperthermia [1]. In this work, we used oils extracted from ucuúba (Virola surinamensis), bacaba (Oenocarpus bacaba Mart.) and açaí (Euterpe oleracea Mart.) to coat Fe3O4 nanoparticles. The ucuúba, bacaba and açaí are native trees of the Amazon forest, whose oils are rich in fatty acids, such as lauric, myristic, steatic, oleic, palmitic, and linoleic acid, with different proportions. These pure oils, free of solvents, were obtained by the extraction method with carbon dioxide in the supercritical state [2], and then added during the synthesis process of iron oxide nanoparticles by thermal decomposition method [3]. The results of X-ray diffraction confirmed the formation of Fe3O4 single phase. The average size around 3 nm and spherical morphology of the magnetite nanoparticles was determined by transmission electron microscopy. The study of magnetic properties revealed a saturation magnetization (Ms) enhancement and high values of the anisotropy constant for Fe3O4 samples when coated with açaí (91.4 emu.g-1; 4.6 105 J.m-3) and ucuúba (80.6 emu.g-1; 9.3 105 J.m-3) oils, which present a large percentage of saturated total fatty acid. The results indicate that nanoparticles with sizes smaller than around 5 nm present Ms values as high as those found in bulk Fe3O4 and higher than those usually obtained for nanoparticles coated with oleic acid [4]. The neutron activation analysis (NAA) nuclear technique was used to determine with high accuracy the mass of Fe in the Fe3O4 core of nanoparticles in order to normalize the magnetization values [5]. These results show that natural oils have a great potential to produce stable and quality nanoparticles as compared with conventional coated.

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  • IPEN-DOC 26821

    NOGUEIRA, A.L.; MUNITA, C.S. ; COSTA, A.F.; GOMES, D.M.C.; KIPNIS, R.. Quantitative methods of standardization in cluster analysis: finding groups in data. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 76-76.

    Abstract: The archaeological study of ceramics using multi-elemental analytical techniques such as instrumental neutron activation analysis (INAA) is important in archaeology due to its potential to identify the raw materials used in their manufacture,and subsequently help to infer the degree of interaction among ancient communities. Several multivariate statistical methods are used in chemical composition data analysis, such as principal component analysis, cluster analysis and discriminant analysis. Pattern recognition approaches are divided into unsupervised learning and supervised learning. Cluster analysis is a technique for pattern recognition and is an unsupervised approach. When applying cluster analysis, raw data, or actual measurements, are not used directly. Thus, a problem that arises during cluster analysis involves the decision of whether or not to standardize the input variables before calculating measures of distance. The standardizationof variables is necessary in cases where the measure of dissimilarity, such as the Euclidean distance, is sensitive to differences in the magnitudes or scales of the input variables. The aim of this paper is to assess the impact, and evaluate the usefulness of three standardization techniques in determining the number of clusters for a data set of 140 ceramic fragments from eight archaeological sites from the upper Madeira river, Rondônia, Brazil, in which Na, K, La, Sm, Yb, Lu, Sc, Cr, Fe, Co, Zn, Rb, Cs, Ce, Eu,Hf, Ta, and Th mass fractions were determined by INAA.

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  • IPEN-DOC 26820

    SANTOS, U.P.M. ; LOURENÇO, F.R.; MOREIRA, E.G. . Experimental design and z-score results are useful tools for optimizing Instrumental Neutron Activation Analysis procedures. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 133-133.

    Abstract: In this study the optimization of procedures of an Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using irradiations up to 60 s at a pneumatic station. 2k experimental designs were applied for assessment of the individual influence of selected variables of the analytical procedure in the mass fraction results. The chosen experimental designs were the 23 and the 24, depending on radionuclide half-lives. Different certified reference materials and multi-element comparators were analyzed, considering the following variables: irradiation time, sample decay time, sample distance to detector and counting time. Gamma ray spectrometer, comparator concentration, and sample mass were maintained constant in this study. By means of statistical analysis experimental considerations, optimized experimental conditions for the analytical methodwere determined and will be adopted for the validation procedure of INAA methods at the Research Reactor Center of the Nuclear and Energy Research Institute (IPEN – CNEN/SP). Optimized irradiation and measurement conditions were established based on experimental design resultsusing the obtained z-scores for the various elements and experimental conditions.

    Palavras-Chave: chemical state; elements; experiment design; isotope ratio; matrix materials; neutron activation analysis; neutron activation analyzers

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  • IPEN-DOC 26819

    SILVA, S.A.; JUNQUEIRA, L.S. ; FRANKLIN, R.L.; SILVA, W.L.; FAVARO, D.I.T. ; MOREIRA, E.G. . Sedimentary profiles from a water supply reservoir at São Paulo, Brazil: trace and rare earth elements assessment by INAA. In: ACHARYA, R. (Ed.); SWAIN, K.K. (Ed.); SATHYAPRIYA, R.S. (Ed.); REDDY, A.V.R. (Ed.); PUJARI, P.K. (Ed.) INTERNATIONAL CONFERENCE ON MODERN TRENDS IN ACTIVATION ANALYSIS, 15th, November 17-22, 2019, Mumbai, India. Abstract... Mumbai, India: Bhabha Atomic Research Centre, 2019. p. 79-79.

    Abstract: A research project has been conducted by the Environmental Company of São Paulo State (CETESB) and the Nuclear and Energy Research Institute (IPEN) in important water supply reservoirs at São Paulo State in order to perform a wide evaluation on the content of rare earths and some trace elements in sediment profiles. In the present study, preliminary results for two sampling campaigns at the Graminha reservoir are presented:February/2015 (sites 1 and 3) and August / 2015 (sites 1 and 2). Sediment core samples (around 90 cm long) were collected in the dam and sliced at every 2.5 cm. Instrumental Neutron Activation Analysis (INAA) was applied to the sediment samples in order to determine some trace elements (As, Cr, Th, U and Zn) and rare earth elements (REE) (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb). The analytical methodology validation was performed by means of certified reference material analyses. As, Cr and Zn concentration values were compared to the oriented values from CCME (Canada) (TEL and PEL). Sediment quality was classified as good or very good for these elements according these criteria. Enrichment factor (EF) and Geoaccumulation Index (IGeo index)1were applied to the results by using the concentration values of the last layer of the 90.0 cm profile as background values for sediment contamination index assessment. EF>1.5 was found for REE, U and Th in the middle of the sediment profiles,in all sampling points, indicative of anthropogenic contribution. IGeo values in the range of1<IGeo<5 were found, being the sediments classified as moderate to very polluted for these elements. The normalization of REE concentrations with respect to a geological reference value, a useful tool to obtain a comparison among information from contamination sources2 was used in the present study by using NASC (North American Shale Composite) and PAAS (Post Archean Australian Shale) normalization as reference values. In addition, La/Sm, La/Yb and Sm/Yb ratios were calculated and discussed.The present study data are intended to start a sediment REE concentration data bank in water supply reservoirs and maybe they can be used in the future to establish legal limits for CETESB.

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  • IPEN-DOC 26818

    ARAUJO, S.G. ; LANDINI, L. ; ZEFERINO, G.R. ; SALVADOR, V.; SCAPIN, M.A. . Resíduos de frutos do mar: oportunidades potenciais para produção de materiais bioativos. In: WORKSHOP DE BIOMATERIAIS, ENGENHARIA DE TECIDOS E ORGÃOS ARTIFICIAIS, 6th, October 29-31, 2019, São Paulo, SP. Abstract... 2019.

    Abstract: Resíduos de frutos do mar: oportunidades potenciais para produção de materiais bioativos Resíduos de frutos do mar são fontes ricas em diversos compostos e materiais bioativos e anualmente, no mundo, milhões de toneladas destes resíduos (conchas, ostras, camarões, caranguejos, lagostas, mariscos, etc) são produzidos. No Brasil, cerca de 2 milhões de toneladas somente no Litoral Sul/SP. Com este problema ambiental, há grande geração de resíduos sólidos de atividades pesqueiras e/ou de maricultura,frequentemente despejados em terrenos baldios, aterros sanitários ou no mar. No entanto, eles embutem grande quantidade de elementos/compostos químicos valiosos (cálcio, quintina, pigmentos, proteínas), e poderiam ser usados para diversas aplicações na medicina, industrias farmacêuticas, alimentícias, energéticas, etc., Estes resíduos normalmente têm seus valores potenciais ignorados e o seu aproveitamento diminuiria a agressão ambiental e geraria renda aos maricultores e pescadores Neste trabalho, resíduos de frutos do mar foram calcinados para converter CaCO3 em CaO, sendo um dos catalisadores sólidos heterogêneos, altamente ativo, mais utilizados em reação de transesterificação de óleos vegetais para produção do biodiesel. Eles foram calcinados a 1000°C e usados em pó (100 a 200mesh). A caracterização antes e após calcinação foi por WDXRF (FRX por dispersão de comprimento de onda),. O teor de Ca era de 36,2% e de 98,8% de CaO, respectivamente. As propriedades catalíticas foram verificadas em testes de produção de biodiesel, em uma unidade reacional com micro-ondas do IPEN. O maior teor de éster metílico, em GC, obtido foi de 98%, em um teste de 11g de catalisador (P-300W; t-1h; T-65°C; 600rpm). As densidades ficaram dentro das especificações (850 a 900kg/m3) - 20°C. Com estes estudos, verificou-se que é possível aproveitar diversos tipos de materiais, empregando metodologias alternativas e mais conscientes, para proteção do meio ambiente.

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  • IPEN-DOC 26817

    FEDERICO, CLAUDIO A.; GONÇALEZ, ODAIR L.; PAZIANOTTO, MAURICIO T.; DIAS, ARTHUR F.; PRADO, ADRIANE C.M.; CALDAS, LINDA V.E. . A statistical evaluation on the cosmic radiation doses on aircrews flying over South America and Caribbean regions. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction There are substantial researches on the cosmic radiation doses received by aircrew on their typical fl ight workload. Most part of these studies was made by measurements onboard aircrafts of some specifi c companies in stablished routes. A recurrent question from countries over South America and Caribbean regions is related on the signifi cance of doses accumulated by aircrews over this region and if those magnitude justifi es a specifi c radiation protection procedure. Methods The evaluation was made by statistical analysis using CARI-6 aircrew radiation dose code and the data are derived from comprehensive records of registered fl ights performed in the South America and Caribbean airspace between 29,000 and 41,000 feet, performed from March 7 to 20, 2009. The analysis of this sample was composed of 80,548 route calculations totalizing 53,163 hours of real fl ights, by means of calculation of each track performed by aircrafts between aeronautic navigation waypoints. Results The analysis identifi es that the typical group of fl ight crew operating over this region receives mean dose rates ranging from 2.65 μSv/h to 2.95 μSv/h depending on the solar cycle. This distribution, integrated over typical workload from Brazilian aircrews results on annual doses ranging from 1.45 mSv to 1.67 mSv. Conclusions The results demonstrate that the typical aircrew fl ying over this region exceeds the annual radiation limit for public (1 mSv). The statistical analysis also shows that this is the case of more than 96% of the aircrew fl ying with this fl ight routine and workload. The presented results can be used by local authorities of countries over this region as a basis to evaluate the convenience on adoption the recommendation from ICRP Publication 132 regarding radiation protection recommendations for aircrews.

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  • IPEN-DOC 26816

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANDREETA, MARCELLO R.B.; YAMAGUSHI, YASMIM Y.; JIUSTI, JEANINI; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of the FTIR technique for the linearity assessment of commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction High dose dosimetry is one of the most important branches of everyday activities related to medical and industrial applications. Nevertheless, the use of materials that respond in a linear manner has advantages over nonlinear materials, since the dose calculation procedure in linear materials relies solely upon direct proportions to the delivered dose. The evaluation techniques are also important to identify the possible linear ranges, and the new Fourier-transform infrared spectroscopy (FTIR) technique has been used to this objective. This work aims to investigate the linearity response and its sensitivity, using mainly the FTIR technique. Methods Cubic samples of a soda-lime glass type with composition of Li2O.2B2O3 + 10 mol% of (0.25Li2O + 0.25La2O3 + TiO2) were irradiated with doses from 1 kGy to 12 kGy, using a 60Co Gamma-Cell system 220. The response was evaluated using the FTIR technique. Results The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR), with its loadings performing a linear regression; from the slope value, the sensitivity of the glass at the absorbed dose range was obtained. The PLSR technique showed, on the range of 1-12 kGy, that the soda-lime glass type presents linearity value of 0.8532 using just three components. The results of the linearity test were obtained for the FTIR technique. Conclusions The FTIR technique was applied to assess the linear behavior based of the glass spectrum, showing its usefulness to identify possible linear dose regions and also the overall sensitivity of the glass samples to dose. Therefore, the results obtained indicate a good linear response, showing therefore a potential use of this glass-soda lime type for radiation dosimetry in high doses.

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  • IPEN-DOC 26815

    PRADO, EDUARDO S.P. ; GONÇALVES, MAX F.S.; MIRANDA, FELIPE de S.; PETRACONI FILHO, GILBERTO; MASSI, MARCOS; POTIENS JUNIOR, ADEMAR J. . Plasma reactor to viabilize the volumetric reduction of radioactive wastes. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction According of the International Atomic Energy Agency – IAEA, nuclear waste, also known as, radioactive waste, is any material containing a higher concentration of radionuclides than those considered safe by the national authorities. In Brazil, there is a National Nuclear Energy Commission to regulate. These wastes can be generated in nuclear power plants, industries, hospitals and research institutes. To permanently dispose of these radioactive wastes of low and medium level of radioactivity safely and cost effectively, these should be transformed into the physical and chemical compounds suitable for radionuclides immobilization with maximum volume and exhaust gaseous reduction. Incineration is used as a treatment for a very wide range of wastes. Incineration itself is commonly only one part of a complex waste treatment system that altogether, provides for the overall management of the broad range of wastes that arise in society. The objective of waste incineration, in common with most waste treatments, is to treat waste so as to reduce its volume and hazard, whilst capturing (and thus concentrating) or destroying potentially harmful substances. The incineration of waste is one of the most widespread and effective technologies allowing considerably to reduce waste volume. In this scope, among the promising technologies for the radioactive waste treatment is the plasma technology that allows reducing substantially the waste volume after exposing them to temperatures above 2500ºC. In the planning and management of radioactive waste, the challenges related to plasma technology are presented as a motivation factor for the possible implantation of plasma reactors in nuclear plants and research centers with the objective of improving the process of radioactive waste treatment. In this way, this work aims to evaluate the use of plasma technology for the incineration of radioactive waste for volumetric reduction and immobilization of this waste. Methods In this work, a plasma reactor was used for waste incineration, and all reactor parameters (electric energy ranges, maximum arc current, maximum working voltage, air fl ow, maximum energy conversion effi ciency, average temperature of heated gas, heated enthalpy) was controlled based on literature. The experiment was carried out in the plasma reactor (laboratory scale) of LPP in the ITA, using plasma torch transferred arc and with gaseous argon oxidizing agent. The electrical and thermal characteristics of the auxiliary systems of the plasma reactor were obtained using transducers and thermocouples. The composition of the gases in the process was analyzed using mass spectrometer and spectrophotometer. Results The accuracy of the data was important to ensure good results in the process, which allowed the extraction of relevant information from the experiments performed. The volumetric reduction reached 92% in relation to the sample before being processed, with a peak temperature of 1800ºC. Although a larger amount of argon fl ow intensify the cooling of the inner wall of the reactor, and further promote the dilution of the plasma, the arc voltage increases, resulting in higher power operation. Conclusions In the present work a high effi ciency thermal transfer torch was characterized , able to validate the use of the plasma jet for the treatment of radioactive waste.

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  • IPEN-DOC 26814

    MATSUSHIMA, L.C.; VENEZIANI, G.R. ; SAKURABA, R.K.; CAMPOS, L.L. . Quality control in “Intensity Modulated Radiation Therapy-IMRT” using thermoluminescent dosimeters. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Quality assurance in radiation therapy included all actions for ensure the maximum dose for the target volume (tumour) and minimum dose for the healthy tissues. The use of thermoluminescent detectors for evaluation of the absorbed doses in treatments that involve the use of ionizing radiation is widespread and well established in clinical routine. The quality measures are employed to validate system performance, such as IMRT quality assurance (QA). An example for IMRT QA is the decision not to treat the patient if the comparison between a point-dose measurement and the planned value exceeds a predefi ned acceptance criterion (±5%). This work aimed the evaluation of absorbed doses with the use of thermoluminescent detectors (TLDs) of lithium fl uoride doped with magnesium and titanium (LiF:Mg,Ti) and a polymethylmethacrylate (PMMA) phantom in Intensity Modulated Radiation Therapy – IMRT planning. Methods In this study the PMMA phantom simulated a patient in treatment. The central cavity (rectangular format) was considered like target volume (tumour) and the others four cavities were considered like organs at risk. The TLDs were positioned inside the cavities; each cavity has an EVA mold for the positioning of TLDs.

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  • IPEN-DOC 26813

    CORREA, J.N.; PASCHUK, S.A.; BARRETO, R.C.; DENYAK, V.; SCHELIN, H.R.; NARLOCH, D.C.; DEL CLARO, F.; HASHIMOTO, Y.; MATIN, A.C.; SILVA, A.C.M.; ZAHN, G.S. ; SILVA, P.S.C. . Evaluation of the maximum emitting layer of Rn-222 in cementitious building materials. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction – Radionuclides present in construction materials are of interest in the view of environmental radioactivity. The limitations established have focused on the concentration of Ra-226 and the consequent exhalation of Rn-222. A physical/mathematical model developed at the Laboratory of Applied Nuclear Physics (LFNA/UTFPR) correlates the exhaled Rn-222 with the Ra-226 inherent to the material. The model considers the exhalation of Rn-222 by a plane surface that simulates exhalation in fl oors, walls and ceilings. Determination of the maximum emitting layer of Rn-222 that effectively exhales is important to support the model. The objective of this research is to determine the maximum emissive layer of Rn-222 that provides internal diffusion and exhalation of radon-222 in cementitious materials. Methods - Cylindrical samples were made of common cement paste and cement paste with sand of high Ra-226 concentration. The samples (thicknesses 1 to 5 cm) were sealed in order to ensure the exhalation of Rn-222 through one surface. Samples and diffusion chambers containing CR-39 solid-state detectors were inserted into a glass vessel. The samples/detectors were stored for 30 days. Subsequently, the detectors were chemically etched and the nuclear tracks in the CR-39 detectors were counted. Results – For each type of sample a curve was fi tted whose threshold indicated the maximum emitting layer. The results obtained on the samples of common cement paste indicated a maximum emitting layer of 2cm. For samples of cement paste with sand with high Ra-226 concentration, no threshold was observed, indicating that the maximum emitting layer is greater than 5cm. Conclusions - The maximum emitting layer thickness of Rn-222 of common materials determined by curve fi tting was 2cm. For materials with high concentration of Ra-226 there is an indication that the emitter layer is larger than 5cm. The obtained results subsidize the physical/mathematical model developed in the LFNA/UTFPR.

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  • IPEN-DOC 26812

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; MORAIS JUNIOR, PEDRO A.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Dosimetric characterization of high-linearity bone radiation detector exposed to gamma-rays. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction In radiation physics, the study of new alternative dosimeters is of interest on the growing branch of dosimetric characterization of solid-state dosimeters for radiotherapy applications in the Medical Physics fi elds. There are innumerous emerging techniques for reading and processing multivariate data to assess the possible linear behavior of dosimeters; such methods are the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. The goal of this work was to expose bone samples to high doses and to use the FTIR spectrophotometry technique to evaluate the sensitivity and linearity of the absorbed profi les using PLSR and PCR analyses. Methods Small cubes with size approximately of 0.5 cm3 composed the bone samples, used in this work. The samples were irradiated in triplicates, with absorbed doses of 10, 100, 250, 400 and 500 Gy using a 60Co Gamma Cell-220 system (dose rate of 1.089 kGy/h); afterwards, the absorbance spectrum of each sample was acquired on a Fourier Transform Infrared (FTIR) Spectrometer (Frontier/Perkin Elmer) with an optical step of 1 nm from 400 nm to 4000 nm. Results The absorbance for high sensitivity peaks was observed for each bone sample, at the 552 nm, 991 nm and 1650 nm wavelengths in decreasing magnitude. The PLSR and PCR techniques showed, on the range from 10 Gy to 500 Gy, for the calibration curves of the system, a linearity of 0.9432 and 0.9422 respectively, using just three components on both methods. Conclusions The results indicate an acceptable linear response, and therefore this material may be an interesting radiation detector.

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  • IPEN-DOC 26811

    VILLANI, D. ; RODRIGUES JUNIOR, O. ; DANTAS, B.M.; CAMPOS, L.L. . Dosimetric characterization of 3D printed phantoms at different infill percentage for diagnostic x-ray energy range. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The use of 3D printing and fi laments commonly found commercially for development of phantoms has been investigated in recent years due to the cost of materials and improvements in the quality of printers. The application of this technique for radiation protection and dosimetry requires a complex study of the quality control and the interaction of printed materials with different radiation beams. The aim of this paper is to characterize 3D printed phantoms and printing set-ups for different infi ll percentages for diagnostic energy beams. Methods 3D printing performance was studied using the RAISE 3D PRO2 printer from IPEN for printing with PLA (Polylactic Acid) and ABS (Acrylonitrile Butadiene Styrene) fi laments. Printing characteristics such as repeatability, reproducibility, effective density by displaced water mass and porosity at 100% infi ll were studied. Plate samples of 8x8x1cm3 were printed and, using the Pantak Seifert irradiator with different x-ray qualities in the diagnostic energy range, the attenuation coeffi cients were obtained experimentally for different percentages of plates infi ll. Results By printing three identical samples for each print mode, the 3D printing system had a repeatability better than 1.0% for masses and average of 0.7% for the dimensions of the printed objects, obtaining the highest variations in small printed parts. Little to no porosity has been found on the printed pieces with 100% infi ll, giving to the printed objects the same density of the chosen fi lament. The attenuation coeffi cients were determined for the different beam qualities and it was verifi ed that the variation in the values decreases as the infi ll quality increases. Conclusions The results show that the printing system have excellent repeatability and print quality. The different printing modes characterized together with their attenuation coeffi cients for the x-ray beams will be studied and used in the development of new 3D printed phantoms in our institute.

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  • IPEN-DOC 26810

    OLIVEIRA, LUCAS N. de ; NASCIMENTO, ERIBERTO O.; ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Evaluation of transparent and black commercial soda-lime glass irradiated with gamma radiation. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction The linearity characteristic in radiation dosimetry presents a growing interest. Glasses have been applied to radiation high doses. The goal of this work was to expose transparent and dark commercial soda-lime glasses samples to high doses and to use the UV-Vis spectrophotometry technique for their evaluation. Methods Transparent and dark commercial soda-lime glasses with dimensions of 1 x 10 x 40 mm3 were irradiated with doses from 1 kGy to 10 kGy using a 60Co Gamma-Cell system 220, and then were evaluated with the UV-Vis technique. The sensitivity and linearity characteristics were evaluated with the absorbed profi les of the multivariate calibration Partial Least Square Regression (PLSR) and Principle Component Regression (PCR) techniques. Results The PLSR and PCR techniques showed, on the range of 1-10 kGy, for the calibration curves, of transparent and black commercial soda-lime glass, linearity values of 0.9432 and 0.9422 respectively using just three components on both methods. The spectra present a baseline variation (and maximum absorbance values) proportional to the absorbed dose received by the samples. These results show that it is possible to use the technique of UV-Vis to determine if the glass samples were irradiated or not. The color changes for transparent glass irradiated with absorbed doses from 1 kGy up to 10 kGy. This color variation in relation to absorbed dose indicates that the glasses may be used as YES/NO dosimeters. Conclusions The UV-Vis measurements may be useful in gamma radiation dosimetry, using the spectra of irradiated glasses; the highest linearity was shown in order respectively for transparent and black commercial soda-lime glass; the glass samples changed their coloration proportional to the absorbed doses, and they may be used as Yes/No detectors and as high-dose dosimeters. The results indicate a good linear response and the radiation detectors present potential use for radiation dosimetry in high doses.

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  • IPEN-DOC 26809

    GONCALVES, J.A.C. ; MANGIAROTTI, A.; ASFORA, V.K.; KHOURY, H.J.; BUENO, C.C. . Dosimetric characterization of thin diodes in an electron beam facility for radiation processing. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction: Silicon diodes have been employed as relative dosimeters in clinical photon and electron beams. However, they are prone to radiation damage that produces a drop of their current sensitivities with increasing accumulated doses. This effect is attributed to the decrease of the minority carrier diffusion lengths which diminishes the sensitive volume of the diode. Theoretically, it is possible to mitigate the decay of the current sensitivity by choosing diodes with thicknesses smaller than the lowest minority carrier diffusion lengths anticipated for the foreseen accumulated dose. This surmise has been followed up in this work by evaluating the response of thin diodes (SFH00206K) for the dosimetry of electron beams used in radiation processing. Methods: The diode with 10 μm of depletion layer at 0V was produced on n type Si wafers of 220 m thickness. As a dosimeter, the device was housed in a probe and connected to an electrometer to be operated in short-circuit current mode without bias voltage. To carry out the irradiation, the probe was placed on a conveyor belt that crosses the radiation fi eld of a 1.5 MeV electron beam. Results: The currents were registered as a function of the exposure time for dose-rates within 2-8 kGy/s and accumulated doses up to 350 kGy. The dosimeter was characterized with respect to the linearity between current and dose-rate, repeatability and reproducibility of the current signals. Its lifespan was investigated, particularly addressing the stability of the current sensitivity factor with increasing absorbed doses. The measurements were benchmarked against calculations of the current taking into account the fraction of the electron energy deposited in the active volume of the diode, the dose-rate, and the values of diffusion lengths. Conclusion: All experimental data so far obtained prove that this diode can be used in electron beam dosimetry. Furthermore, a fair agreement was found between theoretical and experimental results.

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  • IPEN-DOC 26808

    POLO, IVON O. ; SANTOS, WILLIAM S. ; CALDAS, LINDA V.E. . An extrapolation chamber for the establishment of a primary radiation standard in 85Kr and 147Pm beta radiation beams. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction At the Calibration Laboratory (LCI) of the IPEN/CNEN, studies are in development on the establishment of the Böhm extrapolation chamber model 23392 as a primary standard system for the dosimetry and calibration of beta-radiation sources and detectors. This chamber was already characterized at the LCI in 90Sr/90Y beams using two different entrance windows: one of aluminized Mylar and another of Hostaphan. This extrapolation chamber was characterized in 85Kr and 147Pm beams. All tests were carried out with the reference 90Sr /90Y source, for comparative purposes. Methods A Keithley model 6517B electrometer was used for the measurements. The utilized radiation sources are part of the Beta Secondary Standard BSS2. Moreover, the Monte Carlo code MCNP5 was used to determine the absorbed dose rates and to compare them with the experimentally determined dose rates and with those from the PTB calibration certifi cate. Results Saturation curves, ion collection effi ciency, ion recombination, polarity effect, response stability, real null depth, linearity of response, variation of response as a function of sourcedetector distance, extrapolation curves, correction factors and absorbed dose rates were obtained. The ion collection effi ciency was greater than 99%; the ionic recombination was less than 1%, and the polarity effect was greater than 1%. The stability of the response was lower than 0.15% for the repeatability test, and it was less than 0.36% for the reproducibility test. The difference between the experimental absorbed dose rates and those from the Monte Carlo model, compared to those from the calibration certifi cate, was less than 1.9% for all sources. Conclusions All results of the performed tests are within the limits of the international recommendations. The results for the 90Sr/90Y source were in the good agreement with previous works performed at LCI. These results are suitable for the establishment of a primary standard for beta radiation.

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  • IPEN-DOC 26807

    OTERO, ANDRE G.L. ; MARUMO, JULIO T. ; POTIENS JUNIOR, ADEMAR J. . Applying deep-learning in gamma-spectroscopy for radionuclide identification. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Neural networks, particularly deep neural networks, are used nowadays with great success in several tasks, such as image classifi cation, image segmentation, translation, text to speech, speech to text, achieving super-human performance. In this study we explore the capabilities of deep learning on a new fi eld: gamma-spectroscopy analysis. Using a well-known deep neural network architecture with gamma spectroscopy data, we successfully identify the radionuclides (Am-241, Ba-133, Cd-109, Co-60, Cs-137, Eu-152, Mn- 54, Na-24 and Pb-210) contained in several experiments. This neural network is also capable to identify different mixed radionuclide in the same source, demonstrating that deep neural networks can be successfully applied on gamma-spectroscopy analysis. Methods Using a HPGe detector to acquire several gamma spectra, from different sealed sources, we created a dataset that was used for the training and validation of the neural network. We created our deep neural network using python as programing language, alongside with Keras, a deep learning framework. Applying the VGG19 network architecture, except by the last layer which using softmax as activation function, we used sigmoid in order to allow classifi cation of not mutually exclusive classes in the same instance. Results After 250 epochs of training the classifi cation error on the training and test datasets reached a minimum, the same occurred with accuracy. As a fi nal test we used a spectrum from a triple sealed source, containing Am-241, Cs-137 and Co-60. As this kind of data was never seen by the network before we expect that the network generalizes well and correctly classify the spectra as containing the three isotopes. When applying the new data, the model correctly classifi ed the spectra as containing the tree radionuclide. Conclusions The model successfully classifi es different spectra with different radionuclides and his performance is good on never seen before data (the triple source sealed) demonstrating that deep learning can be used on a new domain.

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  • IPEN-DOC 26806

    SAVI, MATHEUS; BERTONCINI, MARCO A.; POTIENS, MARIA da P.A. . Commercial filament testing for use in 3D printed phantoms. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction With the popularization of 3D printing, many areas of knowledge are using this technology to create products and diminish costs, even in health segment. Commercial phantoms are expensive and hard to obtain in development countries. As alternative, 3D printed phantoms can be the way to produce inexpensive and reliable simulators aimed for dosimetry and teaching. That said, the objective of this study is to determine which of the available commercial fi laments can be used in 3D printing to mimic human tissue for use in 3D printed phantoms. Methods Fourteen 3D printing fi laments (ABS, ABS premium, PLA, PLA+Bone, PLA+aluminum, PLA+brass, PLA+cooper, SILK, HIPS, PETG, PVA, Wood, TPU and TPE) commercially available in Brazil had their attenuation tested, using computed tomography. Each material was printed as 2 centimeters edge cube with rectilinear pattern and 60, 80 and 100 percent infi ll. The cubes were scanned in a Philips CT Brilliance 6 with 120 kV, 200 mA, 2mm slices and standard reconstruction. At the center of each cube, an ~ 120 mm² region of interest were set to measure the mean Hounsfi eld Unit (HU) and the standard deviation value. For each material a graphic was plotted and the curve equation determined. Results The HU of the tested materials ranged from -516,2 ± 7,3 to 329,8 ± 18,9. All human tissues could be mimetized with these materials, except bone (mainly cortical bone). Considering the curve equation, the most promising fi lament was PLA+Cooper, due to the multiple infi ll confi guration that allows the resulting HU range to represent from adipose and skin tissue to marrow bone. With a two extruder printer may be possible add lung tissue to the model and make a 3D phantom more complex and accurate. Conclusions With these tested materials, is possible to construct various phantoms, simulating a wide range of tissues. However, any simulator with cortical bone is impaired because none fi lament achieve the required HU value (at least over 800 HU).

    Palavras-Chave: 3d printing; phantoms; fabrication; filaments; radiology; computerized tomography

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  • IPEN-DOC 26805

    NASCIMENTO, ERIBERTO O.; BECATTI, MATHEUS J.P.; ANTONIO, PATRICIA L. ; VIEIRA, SILVIO L.; OLIVEIRA, LUCAS N. de ; CALDAS, LINDA V.E. . Quality control of solar protection films via design of experiments. In: INTERNATIONAL CONFERENCE ON DOSIMETRY AND ITS APPLICATIONS, 3rd, May 27-31, 2019, Lisboa, Portugal. Abstract... Lisboa, Portugal: C2TN, Instituto Superior Técnico, Universidade de Lisboa, 2019.

    Abstract: Introduction Solar radiation reaching the earth surface is broadly divided into infrared, visible and ultraviolet radiation (UVR). Individual dosimetry and monitoring of the sun rays in humans and environments is of interest since in homes, shops and cars the effects of UVR radiation can bring irreparable damage to the skin and eyes. The effi cacy of solar protective fi lms has been recognized as an important public health product. The objective of this work was the quality control of solar fi lms using the UV-Vis spectroscopy technique via 2k Experimental Factor. Methods Four types of solar protective fi lms were tested: G05, G20, G35 and WB (Windom Blue), which follow the blocking of UVR rays by 95%, 80%, 65% and 0% (76% transparent). The samples had dimensions of 1.0 x 3.0 cm2 and the readings were taken on a GENESYS™ 10S UV-Vis Spectrophotometer with an optical step of 1 nm from 190 nm to 400 nm. The absorbances were used in a 2k Experimental Factor, in which the four fi lms were read individually and also with overlap (two fi lms together). It was possible to obtain results of all the interactions among the fi lms, with or without overlap. Results The results about the absorption of the sunscreen fi lms were modeled from the 2k Experimental. This factor indicates that the best regions of the spectrum are blocked and/or where they produce a better quality control of these materials. The region studied in this work was where the ultraviolet radiation dosimetry can be of interest. The proposed spectrophotometric method is rapid, simple and cost effective for the evaluation on quality control of protection fi lms. Conclusions The results provide information on ultraviolet radiation and they can be useful for the medical physics community. The proposed methodology may be useful as a rapid quality control tool. It can be used during the production process, in the analysis of the fi nal product, and can offer important information for the scientifi c community.

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  • IPEN-DOC 26804

    ROSSI, MARIANA C.; BAYERLEIN, DANIEL L.; KRIECK, ANDRE M.T.; BRANDÃO, JAQUELINE de S.; PFEIFER, JOÃO P.H.; ROSA, GUSTAVO dos S.; STIEVANI, FERNANDA de C.; MARTINEZ, LUIS G. ; SAEKI, MARGARIDA J.; ALVES, ANA L.G.. Influence of space holder on the biocompatibility of Ti-34Nb-6Sn alloy prepared by powder metallurgy. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Development of metallic materials for denistry and orthoapedic area have been increasing, due to in world life expectancy and the significantly numbers of accide nts. Due to problems of failure in available commercial materials implantation, as well as the discomfort of patient because the high elastic modulus, these devices need to be improved or news implants should be sought. This study was intended to develop a porous alloy, Ti-34-Nb-6Sn/Mg wich can help the ingrowth bone tissue when implanted, by the powder metallurgy. After the milling powders in the high energy mill, were compacted and sintered. Both, powders and sintered materials were chacarterized by X-ray Difraction (XRD), Scanning Electron Microscopy (SEM) and semi-quantitative compositional analysis (EDS). The apparent porosity was measured through the Arquimed’s Method. The toxicity this material was evaluated by MTT assay, using the equine mesenchemal stem cells derivated of bone marrow (bmMSC) according to ISO 109935. The bmMSCs morphological analysis in contact on the material surface using SEM. The Mg evaporation was confirmed by EDS and XRD after sintering. The XRD indicate there is predominantly beta phase than alpha. The apparent porosity was higher in alloy with Mg space holder. The materials do not presented particular cytotoxic in direct and indirect contact. Metallurgic powder tecnhique promoted effectively macropores formation in Ti-34Nb-6Sn/Mg alloy, wich possibly further bmMSCs adhesion.

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  • IPEN-DOC 26803

    SAEKI, MARGARIDA J.; GARCIA, JOÃO I.M.M.; FERNANDES, CELIO J.C.; ROSSI, MARIANA C.; SILVA, WILLIAM de M.; MARTINEZ, LUIS G. ; ZAMBUZZI, WILLIAN F.. Characterization of titanium surface modified by calcium titanate. In: INTERNATIONAL MATERIALS RESEARCH CONGRESS, 28th, August 18-23, 2019, Cancun, México. Abstract... Ciudad de México, México: Sociedad Mexicana de Materiales, 2019.

    Abstract: Coatings based on apatite and others that contain calcium play an important role for the osseointegration with the implant. It is believed that released calcium induces a specific biological response to the living tissue establishing a stable chemical bonding between formed bone and implants. The mechanical anchorage of implants also depends on the surface structure and morphology. In this work, the titanium surface was modified by calcium titanate, which was deposited by sol-gel method combined to the dip coating technique followed by heat treatments. Two different emersion rate (5 and 10 cm/min) were used as well as the number of coatings were varied. The temperature of this treatment was established based on the results of the thermal analysis (TG/DTA). The surfaces were characterized by X-ray diffractometry (DRX), Scanning Electron Microscopy (SEM) and water contact angle measurement. The corrosion behavior of modified surfaces was evaluated by electrochemical method (polarization curves) in balanced saline Hanks solution. Finally, biological test was carried out by the analysis of cellular viability and adhesion of MC3T3-E1 (subclone 4), mouse pre-osteoblastic cells (ATCC CRL-2593), using MTT and crystal violet assays, respectively, after 24h incubation at 37oC in 5% CO2 atmosphere. The coating consists of anatase TiO2 (PDF 21-1272) and calcium titanate (CaTiO3, PDF 43-226). SEM analysis showed that homogeneous films with 0.8μm of thickness are provided when they are prepared by only one immersion and that the films increase the resistence to corrosion. The coating increases the wettability as the water contact angle decreases from 90o±10o for cp Ti (low interstitial titanium) to 34 o±5o. The biological test shows that the modifications do not interfere on the osteoblast viability and adhesion, however, the morphological analysis of preosteoblasts cultured on the modified Ti-surface by SEM shows that the coatings promote a cell spreading.

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  • IPEN-DOC 26802

    SILVA, ANDERSON M.B.; JUNOT, DANILO O. ; SOUZA, LUIZA F.; SOUZA, DIVANIZIA N.; CALDAS, LINDA V.E. . Caracterização do CaSO4:Tb,Ag para dosimetria OSL. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Embora a dosimetria por OSL seja bem conhecida, o uso dessa técnica tem sido pouco difundido devido à limitação de materiais. Conforme resultados da literatura, a prata como co-dopante em matrizes de CaSO4 dopado com terras raras proporciona um aumento da intensidade das emissões luminescentes em comparação aos materiais sem a prata. Sendo assim, como não há relatos sobre a caracterização estrutural e dosimétrica do CaSO4:Tb com a incorporação de prata, a proposta do presente trabalho foi produzir e caracterizar policristais de CaSO4 dopado com térbio e co-dopado com óxido e nanopartículas de prata. Os fósforos apresentaram uma curva típica de decaimento exponencial de OSL. As amostras de CaSO4:Tb,Ag(nanopartícula) apresentaram sensibilidade OSL cerca de 4 vezes mais intensa em comparação com CaSO4:Tb,Ag(óxido). Ambas as amostras apresentaram curva dose resposta linear na faixa de dose observada e limite inferior de detecção (LID) de 9 mGy para o CaSO4:Tb,Ag(nanopartícula) e 32 mGy para o CaSO4:Tb,Ag(óxido).

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  • IPEN-DOC 26537

    PRESTES, JOAO C.A. ; POTIENS, MARIA da P.A. ; XAVIER, MARCOS . Caracterização de um sistema irradiador utilizado em radioterapia para calibração de dosímetros clínicos. In: CONGRESSO BRASILEIRO DE FÍSICA MÉDICA, 24., 21-24 de agosto, 2019, Santos, SP. Resumo expandido... São Paulo, SP: Associação Brasileira de Física Médica, 2019.

    Abstract: Este trabalho apresenta as etapas de adequação e caracterização de um irradiador de 60Co, que era utilizado para tratamento para que seja utilizado em procedimentos de calibrações de dosímetros clínicos utilizados em radioterapia. Foi realizado a adequação de um sistema irradiador doado ao Laboratório de Calibração do Ipen e a caracterização do feixe e do campo de radiação, de acordo com as recomendações do guia da AIEA (TRS 469, 2009). Para a instalação do novo irradiador, foi realizada uma adaptação na atual sala de calibração para acomodar o cabeçote na posição de calibração. Um suporte foi confeccionado para o seu posicionamento. Na sequência foi necessária a correção no sistema de colimação que apresentou falhas na sua utilização. Para a caracterização do feixe de radiação foram realizados os testes iniciais de uniformidade do campo de radiação determinando o tamanho e o centro do feixe de radiação. Utilizando uma câmara de ionização de pequeno volume foi encontrada uma uniformidade maior do que 90% tanto no sentido vertical como no horizontal, para um feixe de radiação de 8 x 8 cm. As medições para a determinação das taxas de kerma no ar realizadas demonstram que o sistema está pronto para ser utilizado na calibração.

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  • IPEN-DOC 26800

    SILVA, J.C.M.; NTAIS, S.; RAJARAMAN, V.; ANTONIASSI, R.M. ; SPINACE, E.V. ; BARANOVA, E.A.. The catalytic activity of PtRu nanoparticles for ethylene glycol and ethanol electrooxidation in alkaline media. 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. 266-266.

    Abstract: The use of excessive fossil fuels has resulted in harmful effects on the environment and potentially human health. In this sense, direct alcohol fuel cells DAFCs are promising energy producing devices. Ethanol and ethylene glycol are appealing fuels for DAFCs due to their lower toxicity and high theoretical energy density, 8.01 kWh kg−1 and 5.2 kWh kg−1, respectively [1,2]. In this study, the carbon-supported PtRu nanoparticles with atomic ratios of Pt:Ru of 100:0, 90:10, 70:30 and 50:50 for ethanol and ethylene glycol electrooxidation in alkaline media, was investigated. The nanoparticles were synthesized using sodium borohydride method with 20 wt% of metals loading on carbon [1]. X-ray diffraction (XRD) analysis revealed that Pt and PtRu electrocatalysts have face centered cubic (fcc) structure and suggests the alloy formation for all PtRu/C materials, which was further supported by the X-ray Photoelectron Spectroscopy (XPS). According to transmission electron microscopy (TEM) the nanoparticle mean sizes were 7.3 nm, 5.7 nm, 5.2 nm and 5.1 nm for Pt/C, Pt90Ru10/C, Pt70Ru30/C and Pt50Ru50/C, respectively. Electrochemical measurements carried out in mol L-1 KOH + mol L−1 alcohol solution (ethanol and ethylene glycol) in a conventional three-electrode electrochemical cell (glassy carbon was used as work electrode and a platinum foil and a Hg/HgO were used as the counter and reference electrodes, respectively) demonstrated that the addition of Ru to Pt enhances the catalytic activity towards ethanol and ethylene glycol electrooxidadion in alkaline media. The catalyst of Pt50Ru50/C composition showed the lowest onset potential for ethanol and ethylene glycol electrooxidation (by Cyclic voltammetric), which are 160 mV and 70 mV lower than for Pt/C, respectively. Furthermore, this catalyst outperformed Pt/C and other PtRu/C compositions in chronoamperommetric and direct alcohol fuel cell (DAFC) experiments. DAFC experiments using Pt50Ru50/C as anode had the power density 40% and 14 % higher than using Pt/C for ethanol and ethylene glycol, respectively. The enhancement of the catalytic activity might be related to the high amount of oxides species on the Pt50Ru50 electrocatalysts surface, which could form Ru-OH at low potential and also due to the electronic effect of PtRu alloy that weakens the adsorption strength of poisonous intermediates from reactions [3].

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Exemplo:

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

Autor: Maprelian

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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.

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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.


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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.