REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

 

 

Apresentação

 

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. [Saiba mais]

 

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Submissões recentes

  • IPEN-DOC 27006

    GOULART, F. ; ICHIKAWA, R.U. ; TURRILLAS, X.; MARTINEZ, L.G. . Study on the microstructure of UNS S32304 duplex steel submitted to heat-treatments. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 45-48. DOI: 10.5151/phypro-viii-efa-12

    Abstract: Duplex stainless steels are characterized by a good combination of mechanical properties and corrosion resistance. Due to the metastable equilibrium between the ferritic (α) and austenitic (γ) phases, significant changes in the microstructure of these steels may occur when subjected to temperatures higher than the ambient, degrading their properties. In this work, it was investigated the influence of heat treatments on the microstructure and mechanical properties of a duplex stainless steel UNS-S32304. The heat-treatments were performed at four temperatures (300°C, 600°C, 900°C and 1000°C) with two treatment times (1 h and 6 h) and two processes of cooling down (in air and water). The samples were studied by X-ray diffraction using Pawley method to determine the lattice parameters, mean crystallite sizes and microstrain for the two phases and compared to Vickers microhardness results.

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  • IPEN-DOC 27005

    REIS, L.A.M. ; ALENCAR, M. ; GOMES, M.P. ; PEREIRA, L.A.T. ; MUCSI, C.S. ; ROSSI, J.L. . Study of recycling process viability of zirconium alloys chips for melting in VAR furnace. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 65-67. DOI: 10.5151/phypro-viii-efa-16

    Abstract: Cavacos de ligas de zircônio (M5, Zirlo, Zircaloy) são gerados em elevadas quantidades na confecção de tubos e tampões das varetas que compõem o elemento combustível de reatores de potência refrigerados a água pressurizada (PWR). Essas são ligas importadas e por isso é mostrado interesse pela indústria de reciclagem na sua reutilização. Este trabalho apresenta os estudos de um processo de reciclagem e a obtenção de eletrodos prensados para serem fundidos em um forno VAR (Vacuum Arc Remelting). O processo se inicia com uma separação magnética, lavagem do fluido de corte que é solúvel em água, utilização de um desengraxante industrial, seguido por um enxágue com fluxo contínuo de água em alta pressão e secagem por fluxo de ar quente. Para a obtenção de eletrodos, os cavacos foram prensados em uma matriz de seção quadrada 40x40 mm² com 500 mm de comprimento, resultando num eletrodo com 20% da densidade aparente da liga. A fusão foi feita um forno VAR de laboratório no CCTM-IPEN, gerando um lingote maciço de 0,8 kg. A fusão dos cavacos é possível e viável em um forno VAR o que reduz em até 40 vezes o volume de armazenamento desse material.

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  • IPEN-DOC 27004

    ABBADE, L. ; LARA, J.A.C. ; COUTO, C.P. ; GONSALEZ, B. ; COLOSIO, M.A.; ROSSI, J.L. . Resistance spot welding characterization of press hardened steel. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 10-13. DOI: 10.5151/phypro-viii-efa-03

    Abstract: In the automotive industry the resistance spot welding (RSW) is one of the most used processes for joining steel sheets, being of fundamental importance the quality assurance of this process. In this work, 22MnB5 steel sheets for the hot stamping process, also known as PHS (Press Hardening Steel), were joined by the technique of resistance spot welding, so that the welding parameters were changed 16 times for the evaluation of the influence of these parameters on the mechanical properties. By conducting ultrasonic, tensile and hardness test, followed by metallography, it was possible to identify the characteristics of the spot weld effect on the material. The results of the tests performed in this work confirmed the difference in mechanical strength of the thermal zone (ZTA) in relation to the molten zone (ZF). For a certain set of the parameters it was shown a decrease in the strength of the ZTA and increasing to the weld point, which is demonstrated in the microstructural analysis and thus justifies the detachment of the weld button of the base material during tensile testing, i.e., there was a higher strength in the welded area.

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  • IPEN-DOC 27003

    NASCIMENTO, J.O. do; PEREIRA, H.B.B.; MORET, M.A.; BARBOSA, L.P. ; TAKIISHI, H. . Redes semânticas em Ciências dos Materiais: uma aplicação da Teoria de Redes. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 116-121. DOI: 10.5151/phypro-viii-efa-27

    Abstract: Uma possibilidade de estudos em sistemas complexos corresponde a utilização da Teoria de redes sociais e complexas. Este artigo tem como objetivo descrever e analisar as redes semânticas baseadas nas palavras-chave dos artigos publicados nos anais do Congresso Brasileiro de Engenharia e Ciências dos Materiais (CBECiMat) referente ao ano de 2010. Alicerçamo-nos nas métricas de estatística básica pertencente às redes complexas, ao índice de centralidade de grau pertencente as redes sociais e apresentamos o método de construção das redes semânticas. As análises indicaram quais as palavras-chave se destacaram (por meio do número de suas conexões) e as topologias verificadas, sugerem redes livre de escala e mundo pequeno. Estes resultados auxiliam na escolha e observância de palavras-chave em futuros trabalhos nas áreas de ciências dos materiais e do evento (materiais cerâmicos, materiais compósitos, materiais metálicos, materiais poliméricos e ensino de materiais), bem como arguir sobre estratégias em mecanismos de busca de trabalhos científicos, tendo como descritores as palavras-chave.

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  • IPEN-DOC 27002

    GOMES, M.P. ; SANTOS, I.P. ; COUTO, C.P. ; BETINI, E.G. ; COLOSIO, M.A.; ROSSI, J.L. . Microstructural characterization of air quenched valve seat inserts obtained with AISI D2 tool steel. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 42-44. DOI: 10.5151/phypro-viii-efa-11

    Abstract: The obtention of valve seat insert (VSI) by powder metallurgy using a mixture of iron powder and tool steel is fulfilling the requirements for substitution of cobalt and lead in commercial parts, aiming cost reduction and avoid the lead toxicity. The aim of this work consisted of evaluate the influence of heat treatment on VSI obtained with AISI D2 tool steel powder. The AISI D2 tool steel powder was mixed with iron powder and additives such as manganese sulphide, zinc stearate, graphite and carbides. The heat treatment of the VSI consisted of air quenching followed by double tempering it at 500 °C. The microstructural characterization was performed using scanning electron microscopy and energy dispersive spectroscopy.

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  • IPEN-DOC 27001

    GOMES, M.P. ; SANTOS, I.P. ; REIS, L.A.M. ; CIONE, F.C. ; COLOSIO, M.A.; ROSSI, J.L. . Influence of air quenching on apparent hardness of valve seat inserts obtained with AISI M2 high-speed steel powder. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 39-41. DOI: 10.5151/phypro-viii-efa-10

    Abstract: The aim of this work consisted of evaluate the influence of heat treatment on sintered valve seat inserts (VSI) obtained with the AISI M2 high-speed steel powder. The AISI M2 high-speed steel powder was mixed with iron powder and additives such as manganese sulphide, zinc stearate, graphite and carbides. The heat treatment of the VSI consisted of air quenching followed by double tempering it in seven different equidistant temperatures, from 100 °C until 700 °C. The mechanical property was measured regarding the VSI apparent hardness. The results indicated that the VSI obtained with the AISI M2 high-speed steel powders mixtures showed the best results regarding its apparent hardness after air quenching and double tempering it at 600 °C.

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  • IPEN-DOC 27000

    BETINI, E.G. ; GOMES, M.P. ; REIS, L.A. ; MUCSI, C.S. ; ALENCAR, M.C. ; ORLANDO, M.T.D.; LUZ, T.S.; AVETTAND-FENOEL, M-N.; ROSSI, J.L. . Effect of the cooling rates on heat-affected zone of UNS S32304 duplex stainless steel welded by pulsed GTAW process. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 14-18. DOI: 10.5151/phypro-viii-efa-04

    Abstract: Two thin plates of UNS 32304 of duplex stainless steel were joined by pulsed gas tungsten arc welding (GTAW) using a mixture 98% of argon plus 2% of nitrogen as shielding gas or pure argon as purging gas at the bottom of the plate without filler metal. The temperature profile close and away from the weld pool was measured using K type (Ni-Cr) thermocouples, connected to a digital data acquisition system. The thermal cycles was recorded in the heat-affected zone (HAZ) at a distance in between 1 and 3 mm from the joint line. The cooling rate and holding time were studied with respect to the used purging gas. Experimental thermal profiles are in good agreement with literature values. The joints welded without any purging gas revealed high peak temperature and cooling rates. The present investigation showed that temperature peaks are comprised in the phase transformation temperature ranges for the welded duplex stainless steel.

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  • IPEN-DOC 26999

    PASCOATO, R. ; ARANHA, L.C. ; MUCSI, C.S. ; ROSSI, J.L. . Desenvolvimento de um torquimetro para medição dinâmica de microtorque. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 62-64. DOI: 10.5151/phypro-viii-efa-15

    Abstract: Foi desenvolvido um dispositivo protótipo de um torquímetro para ensaio de medição dinâmica de micro torques. Este dispositivo foi usado para a avaliação de implantes ortodônticos. O ensaio consistiu na inserção e retirada de pilares protéticos em implantes odontológicos, com torques menores que 100 Ncm. O principal componente desse protótipo foi a barra de torque, nesta, foi aplicado um extensômetro tipo strain gage. As deformações sofridas por este componente, não descriminavam entre deformações devido a tensões de flexão e tensões de torção. Com o propósito de diminuir esta sensibilidade a deformação por flexão e aumentar a sensibilidade da torção, foi proposta uma nova geometria para a barra de torque. Após ser estudada analiticamente, esta nova geometria mostrou- se bastante favorável quanto ao aumento da sensibilidade à torção do componente e a diminuição da interferência devido ao seu peso próprio.

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  • IPEN-DOC 26998

    SOUZA, A.C.; SILVA, A.C.; ROSSI, J.L. ; CIONE, F.C. . Analysis thermogravimetric of tungsten composite for gama radiaction shielding. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 36-38. DOI: 10.5151/phypro-viii-efa-09

    Abstract: The generation of Mo-99mTc generators for hospitals requires the transport of the Mo-99m material in containers with physicochemical properties for especially the shielding of gamma radiation [4, 5]. The application of tungsten alloys has been developed with the objective of minimizing the effects of radiation, being used in the manufacture of devices for the transport of radioactive material, considering its properties of specific mass (60% dense than lead), resistance corrosion, excellent absorption of high energy radiation and high mechanical strength [16,17]. The kraft lignin, a natural polymer obtained from the Kraft process of cellulosic pulp extraction, considered a residue of the cellulosic industry, can be used as a high adhesive material. The objective of this work was to perform the Thermogravimetric (TG), Differential Exploration Calorimetry (DSC) and X-ray diffraction (XRD) analyses of a new composite of tungsten and kraft lignin. The results showed the thermal and crystallographic properties of the composite, which could contribute to obtain a new material with ability to attenuate gamma radiation.

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  • IPEN-DOC 26997

    SOUZA, A.C.; ROSSI, J.L. ; FERNANDES, H.B.; GOUVEA, A.F.G.. Analysis of the microstructural evolution of composite of Tungsten with lignin kraft. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 76-78. DOI: 10.5151/phypro-viii-efa-19

    Abstract: In materials science and engineering, there is a demand in new materials for radiation shielding in the transport of radiopharmaceuticals used in the diagnosis and therapy of cancer, justifying the interest in developing this work. The obtained lignin kraft and tungsten form the precursors used for metal-organic composite. Tungsten metal has diverse applications in the nuclear sector presents an enormous mechanical strength and an excellent cross section with thermal neutrons. The aim of this study is to analyse the microstructural evolution of metal-organic composite using the kraft lignin and tungsten, using analysis of scanning electron microscopy (SEM), microhardness test and x-ray diffraction (XRD). Microscopic analysis showed the granulometry of the precursors separate and composite morphology, observing the formation of alpha (α) and beta (β) phases and absence of oxidation process for different heat treatment temperatures. The spectra of x-ray diffraction identified the structures of each phase formed and micro hardness measures showed an increase of mechanical resistance with temperature. The results of the microstructural characterization of metal-organic composite, will contribute in the next steps of attenuation measurements of gamma radiation.

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  • IPEN-DOC 26996

    COSTA, P.D.O.L. ; COSTA, I. ; COUTO, C.P. ; ROSSI, J.L. . Análise gravimétrica do revestimento de zinco-níquel de um aço 22MNB5 e zinco puro. In: ENCONTRO CIENTÍFICO DE FÍSICA APLICADA, 8., 4-7 de setembro, 2017, Vitória, ES. Anais... São Paulo, SP: Blucher Proceedings, 2017. p. 29-31. DOI: 10.5151/phypro-viii-efa-07

    Abstract: O aço de alta resistência 22MnB5 é utilizado com revestimento de alumínio-silício com o objetivo de melhorar a resistência a corrosão e desgaste em peças expostas em meios molhados que favorecem o fenômeno corrosivo. Sua principal aplicação é no setor automobilístico englobando peças que integram a estrutura principal do veículo. Uma alternativa para a substituição do revestimento alumínio-silício é uma composição química do revestimento utilizando zinco-níquel. Neste trabalho foi estudado a evolução do processo de perda de massa em diferentes meios corrosivos (ácido, neutro e alcalino) identificando o comportamento do material revestido do aço 22MnB5 e comparando com zinco puro. Foram utilizados três variáveis: revestimento zinco-níquel como recebido, revestimento zinco-níquel estampado e zinco puro. Foi constatado que em meios ácidos (pH de 0 a 1) o processo de corrosão foi muito intenso para todos os materiais, do pH 3 ao pH 13 a perda de massa foi insignificante, mesmo sendo imersa durante dias, havendo a proteção do material pela camada passiva formada de óxido. O revestimento estampado se mostrou com maior tendência a perda de massa, por possuir mais defeitos em sua superfície facilitando o processo corrosivo enquanto que o revestimento como recebido se mostrou bem resistente.

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  • IPEN-DOC 26995

    RAMANATHAN, L.V. ; FERNANDES, S.M.C. ; CORREA, O.V. ; SOUZA, J.A. de ; ANTUNES, R.A.; OLIVEIRA, M.C.L. de. Coatings for safe long term wet storage of spent Al-clad research reactor fuels. In: INTERNATIONAL CONFERENCE ON RESEARCH REACTORS: SAFE MANAGEMENT AND EFFECTIVE UTILIZATION, November 16-20, 2015, Vienna, Austria. Proceedings... Vienna, Austria: International Atomic Energy Agency, 2015. p. 1-8.

    Abstract: Pitting corrosion of the aluminium cladding of spent research reactor (RR) fuels in wet storage has been observed and the use of conversion coatings to protect the cladding was proposed. A coating prepared by conventional chemical processing as opposed to electrochemical processing is the only option due to constraints related to the shape of the fuel and its high radioactivity. Hence, hydrotalcite (HTC) and boehmite were considered. This paper presents: (a) preparation of hydrotalcite (HTC) coatings from different baths followed by post-coating treatments; (b) corrosion behavior of HTC coated AA 6061 alloy; (c) results of field studies in which uncoated and HTC coated AA 6061 alloy coupons and plates, the latter assembled as a dummy fuel element, were exposed to the IEA-R1 reactor spent fuel basin for extended periods. The laboratory and field tests revealed marked improvements in the corrosion resistance of HTC coated specimens, coupons and plates. The mechanism of corrosion protection is presented.

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  • IPEN-DOC 26994

    GOMES, M.P.; SANTANA, M.S.; ROSSI, J.L. ; POLITANO, R. . Estudo da energia mecânica necessária para a geração de pulsos mecânicos em uma barra de Kolsky. In: CONGRESSO CIENTÍFICO DA SEMANA NACIONAL DE CIÊNCIA E TECNOLOGIA NO IFSP, 6., 20-23 de outubro, 2015, Bragança Paulista, SP. Anais... Bragança Paulista, SP: Instituto Federal de São Paulo - Bragança Paulista, 2015.

    Abstract: A análise da resposta a pulsos mecânicos em materiais a serem utilizados em sistemas para transporte de substâncias radioativas é uma das condições para a sua respectiva seleção e dimensionamento. Para que se faça a caracterização da resposta dos materiais candidatos a este tipo de solicitação é necessária a construção de aparatos experimentais, sendo que neles é aplicado um pulso mecânico de forma controlada e com parâmetros conhecidos, possibilitando assim a obtenção das características mecânicas do corpo-de-provas - aparato este conhecido como barra de Kolsky. Uma parte crítica do aparato, é o alinhamento de todo o conjunto, pois o ensaio a ser realizado é considerado unidimensional. O menor desalinhamento irá causar distorções na onda mecânica de compressão, então os dados obtidos pela extensometria na superfície das barras não serão condizentes com a realidade. Portanto, o propósito deste projeto foi o de produzir um mancal que possibilitasse o alinhamento com uma maior precisão dos eixos x, y do aparato. Tal alinhamento será inicialmente feito manualmente, porém no dimensionamento e concepção do mancal foi reservado um espaço para o acoplamento de um servomotor, que futuramente irá ser utilizado para o ajuste preciso e automático do aparato.

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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 26992

    FERREIRA, ALLANA C.P.; SANTOS, ELINALDO N. dos; MESQUITA, ARIMATEA P. de P.; ARAUJO, EDVAL G. de; GONZALEZ, CEZAR H.; AMBROZIO FILHO, FRANCISCO ; ARAUJO FILHO, OSCAR O. de. Endurecimento secundário do aço rápido AISI M3:2 nome comercial Sinter 23 produzido por uma técnica de metalurgia do pó / Secondary hardening of an AISI M3:2 high speed steel named Sinter 23 produced through powder metallurgy techniques. In: ABM WEEK; CONGRESSO ANUAL DA ABM, 70.; ENCONTRO NACIONAL DE ESTUDANTES DE ENGENHARIA METALÚRGICA, DE MATERIAIS E DE MINAS,15., 17-21 de agosto, 2015, Rio de Janeiro, RJ. Proceedings... São Paulo, SP: Blucher Proceedings, 2015. p. 1755-1762.

    Abstract: O endurecimento secundário de aço rápido AISI M3:2 nome comercial Sinter 23 obtido por uma técnica de metalurgia do pó de sinterização por compactação isostática a quente é objeto desse trabalho de pesquisa. O aço rápido em questão foi austenitizado em banho de sal a 1.140°C, 1.160°C, 1.180°C e 1.200C, temperado ao ar e revenimento a 540°C, 560°C e 580C. Amostras do aço rápido foram fabricadas e submetidas ao tratamento térmico acima descrito e submetida a ensaios de dureza Vickers e Rockwell C para a determinação das suas respostas ao tratamento térmico de endurecimento e avaliação do pico de endurecimento secundário através dos resultados de dureza.

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  • IPEN-DOC 26991

    DEL BUSSO, NICOLANGELO; MONTEIRO, WALDEMAR A. . Caracterização microestrutural e mecânica de aço API-5L-X70 após soldagem pelo método de arco submerso / Mechanical and microstructural characterization in API 5L X70 steel after submerged arc welding process. In: ABM WEEK; CONGRESSO ANUAL DA ABM, 70.; ENCONTRO NACIONAL DE ESTUDANTES DE ENGENHARIA METALÚRGICA, DE MATERIAIS E DE MINAS,15., 17-21 de agosto, 2015, Rio de Janeiro, RJ. Proceedings... São Paulo, SP: Blucher Proceedings, 2015. p. 1665-1674.

    Abstract: A soldagem é um processo industrial empregado na indústria do petróleo e em minerodutos devido ao sua excelente resistência mecânica. Os seus parâmetros provocam alterações metalúrgicas significativas no metal de solda. Neste trabalho foi estudado o aço microligado da classe API-5L-X70 em termos de microestrutura (metalografia e fratografia por microscopia óptica e eletrônica) e propriedades mecânicas (ensaio de tração a temperatura ambiente, dureza, dobramento e ensaio de impacto Charpy a – 20o C e a 0o C) após soldagem em arco submerso, nas regiões da zona fundida (ZF), zona termicamente afetada (ZTA) e metal de base (MB). O exame metalográfico apresentou microestrutura bandeada consistindo de ferrita poligonal, perlita e bainita, com pequeno tamanho de grão. Os resultados mostram o aumento da resistência mecânica influenciada pela presença de ferrita acicular. Análise fratografica apos ensaios mecânicos revelam comportamento dúctilfrágil.

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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 26989

    SANTOS, A.S.; BITTENCOURT, C.. Gas mitigation in paper production. IOP Conference Series: Earth and Environmental Science, v. 78, p. 1-8, 2017. DOI: 10.1088/1755-1315/78/1/012009

    Abstract: The Brazilian paper industry has competitive advantages offered by the favorable climate, which favors an increase in the yield of forest restoration, and consequently, in the productive process. On the other hand, following the greenhouse gases (GHG), we can see our constantly changing sun, causing the solar storms, allowing their prevention or mitigating measures. The objective of this work is to contribute to the construction of the understanding necessary for the reduction of GHG emission from a preliminary analysis of the pulp and paper sector. As a secondary objective, the text preliminarily analyzes a company's behavior against the backdrop of the Paris Accord, which strengthens the global response to the threat of climate change and strengthens the capacity of countries to deal with the impacts of such changes. The identification of best practices in the pulp and paper industry is understood, focusing on environmental sustainability, such as the adoption of reforestation, obtaining significant results. In the case of the paper industry, the management of public forests for sustainable production, within the structure of the Ministry of the Environment, establishes the promotion of public awareness about the importance of conservation, recovery and sustainable management of forest resources.

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  • IPEN-DOC 26988

    GUERRERO-RASCADO, J.L.; ALADOS-ARBOLEDAS, L.; BENAVENT-OLTRA, J.A.; CAZORLA, A.; CHAMIZO, S.; FOYO, I.; GRANADOS-MUNOZ, M.J.; KOWALSKI, A.S.; OLMO, F.J.; PEREZ-RAMIREZ, D.; SERRANO-ORTIZ, P.; TITOS, G.; CASQUERO-VERA, J.A.; ORTIZ-AMEZCUA, P.; COSTA, M.J.; LOPES, F.J.S. ; LYAMANI, H.; PEREZ-PRIEGO, O.; PREISSLER, J.; MARTIN-TRIGO, O.. E-learning in the teaching-learning process at postgraduate level: application to geomet subjects. In: GOMEZ CHOVA, L. (Ed.); LOPEZ MARTINEZ, A. (Ed.); CANDEL TORRES, I. (Ed.) INTERNATIONAL CONFERENCE ON EDUCATION AND NEW LEARNING TECHNOLOGIES, 9th, July 3-5, 2017, Barcelona, Spain. Proceedings... Valencia, Spain: IATED Academy, 2017. p. 2699-2704. DOI: 10.21125/edulearn.2017.1561

    Abstract: This teaching innovation project arises from experience previously gained with other innovation projects encompassing several degrees with the aim of improving the academic performance of the students and the quality of teaching in several subjects of the Master’s program in Geophysics and Meteorology (GEOMET) at the University of Granada (Spain). Among other novelties, through this project resources have been developed for students to carry out an online self-assessment of their knowledge regarding contents of the different subjects through the Moodle platform, checking the level of skills acquired. In addition, the project includes a system of exchange of teaching, electronic resources between teachers and students (guides of subjects, viewgraphs, practical documents, among others). This platform has increased the coordination between the lecturers who teach the subjects.

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  • IPEN-DOC 26987

    MOREIRA, TATIANA M. ; SEO, EMILIA S.M. . Caracterização e utilização das fibras da casca da laranja como biossorvente na recuperação de corpos hídricos contaminados por derramamento de derivados do petróleo. In: CONGRESSO DA ASSOCIAÇÃO BRASILEIRA DE ENGENHARIA SANITÁRIA E AMBIENTAL; FEIRA NACIONAL DE SANEAMENTO E MEIO AMBIENTE, 2-6 de outubro, 2017, São Paulo, SP. Proceedings... Rio de Janeiro, RJ: Associação Brasileira de Engenharia Sanitária e Ambiental, 2017. p. 1-10.

    Abstract: Com base no desenvolvimento sustentável, este trabalho, visou buscar materiais tecnológicos com enfoque na reciclagem, onde se destacam as fibras vegetais, como as da laranja, que possuem baixo custo e impacto ao meio ambiente, com boa eficiência quando utilizadas para o processo de biossorção. Este método vem sendo utilizado como um recurso para redução de problemas ambientais causados por contaminação em corpos hídricos, como córregos e rios urbanos, por derramamento de substâncias tóxicas, minimizando assim os impactos dos ecossistemas aquáticos, bem como a contaminação do solo. A preparação destas fibras foi feita por meio de tratamentos físicos e químicos, tais como: lavagem, secagem, moagem, mercerização (tratamento químico com agente alcalino que ataca a superfície da fibra, melhorando suas características de sorção), classificação granulométrica e caracterização. Esses procedimentos geraram um material que pôde ser empregado como um biossorvente. Como contaminantes, foram utilizados derivados do petróleo, tais como a gasolina e o óleo diesel. Na caracterização foram utilizadas técnicas de: Picnometria, Termogravimetria, Análise Elementar, Microscopia Eletrônica, Fluorescência de Raios X, Teor de Umidade e Cinzas, Retenção de água, Hidrofobicidade e Flutuabilidade. Para os ensaios práticos foram mensuradas a sorção de contaminantes tanto em sistema seco, onde os contaminantes estão em contato direto com os biossorventes, quanto aquoso, simulando um derramamento de óleo diesel e gasolina em um corpo hídrico. Os resultados demonstraram que o biossorvente testado possui boa capacidade sortiva nos dois sistemas testados. Portanto, dada a sua origem renovável e de baixo custo, este material se mostrou eficiente para a finalidade proposta.

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  • IPEN-DOC 26986

    MILAGRE, MARIANA X. ; MACHADO, CARULINE S.C. ; ARAUJO, JOAO V. ; ASTARITA, ANTONELLO; PEBERE, NADINE; VIVIER, VINCENT; COSTA, ISOLDA . Intergranular corrosion susceptibility of Al-Cu-Li alloys. In: EUROPEAN CORROSION CONGRESS; INTERNATIONAL CORROSION CONGRESS, 20th; PROCESS SAFETY CONGRESS, September 3-7, 2017, Prague, Czech Republic. Proceedings... Frankfurt, Germany: European Federation of Corrosion, 2017.

    Abstract: In the present study, the intergranular corrosion (IGC) susceptibility of commercial Al-Cu-Li alloys of the third generation (AA2098-T351, AA2198-T3 and AA2198-T851) was compared with that of the AA2024-T3 alloy according to ASTM G110 test. In addition, anodic and cathodic polarization curves were carried out in the ASTM G110 test solution at room temperature. The cross-section of the samples after the ASTM G110 test was observed by scanning electron microscopy (SEM) to evaluate the extension of the corrosion attack. The susceptibility to intergranular attack of the tested alloys was ranked according to the attack by IGC and from the anodic and cathodic polarization curves. The results showed that the AA2024-T3 and the AA2198-T3 alloys presented higher susceptibility to intergranular corrosion comparatively to the other alloys tested (AA2098-T351 and AA2198-T851). The AA2098-T351 alloy was associated to the highest resistance to intergranular attack among the alloys evaluated. A correlation was seemingly established between the stress relief treatment of the alloy and its corresponding susceptibility to intergranular or intragranular corrosion.

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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 26984

    ABREU, C.P. ; MELO, H.G. de; PEBERE, N.; MOGILI, N.V.V.; COSTA, I. ; VIVIER, V.. Corrosion resistance evaluation of the different zones on the AA2024-T3 and AA7475-T651 alloys welded by FSW. In: EUROPEAN CORROSION CONGRESS; INTERNATIONAL CORROSION CONGRESS, 20th; PROCESS SAFETY CONGRESS, September 3-7, 2017, Prague, Czech Republic. Proceedings... Frankfurt, Germany: European Federation of Corrosion, 2017. p. 1-14.

    Abstract: The aeronautic industry has a great interest in joining dissimilar aluminium alloys used in different parts of an aircraft. The Friction Stir Welding (FSW) process has been considered an effective alternative to conventional techniques for the welding of high strength alumin-ium alloys. However, this procedure results in zones with different microstructures due to thermal and thermomechanical effects involved during the joining process, leading to the formation of the thermomechanically affected zone (TMAZ), the heat affected zone (HAZ), the stir zone (nugget), and the unaffected base metal (BM). As the corrosion resistance of materials depends on their microstructures, the aim of this study was to investigate the intrin-sic corrosion resistance of the different zones of the AA2024-T3 and AA7475-T761 alloys welded by FSW, without considering the coupling effects between the different zones. This was achieved by evaluating the corrosion resistance of each individual zone in 0.1 M Na2SO4 + 1 mM NaCl solution by electrochemical techniques, such as open circuit potential meas-urements, polarization curves, and electrochemical impedance spectroscopy, using an elec-trochemical cell with an exposed area of 0.78 mm2. The electrochemical results showed that the lowest corrosion resistance was associated to the nugget zone, on which a galvanic cou-pling between the 2024 and 7475 alloys takes place. The corrosion resistance was also low-ered on the TMAZ of both alloys. This behaviour was associated to the enhanced precipita-tion of the η phase (MgZn2) at the grain boundaries in the 7475 alloy and to the coarsening of S phase (AlCuMg) precipitates in the 2024 alloy, both processes favoured by the thermome-chanical effects in these specific zones as demonstrated by TEM analysis.

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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 26982

    FERREIRA, E.G. ; MARUMO, J.T. ; VICENTE, R. ; LANGTON, C.A.; DUNCAN, A.J.; WILLIAMS, M.R.. Test methods for cementitious seal materials for borehole disposal. In: ANNUAL WASTE MANAGEMENT CONFERENCE, 43rd, March 5-9, 2017, Phoenix, Arizona, USA. Proceedings... Tempe, Arizona, USA: Waste Management Symposia, 2017. p. 1-13.

    Abstract: The Nuclear and Energy Research Institute (IPEN-CNEN/SP) in Sao Paulo-Brazil, is considering borehole disposal of disused sealed radioactive sources (DSRS), which were used in smoke detectors, lightning arrestors, radiotherapy, industrial gauges, irradiators, and other applications. The current IPEN concept of borehole is a modified BOSS system developed by the International Atomic Energy Agency (IAEA). It differs from the IAEA’s design in that the disposal zone is below 300 m, and the DSRS are placed directly in the disposal packages constituted of stainless steel containers with 1.5 L capacity. A borehole drilled through sediment and granite, stabilized with stainless steel casing and cement grout is proposed for the conceptual model. Standard cement-material test methods and performance specific test methods, including accelerated aging methods, are needed for modeling the performance of the candidate cementitious grouts. A cross-disciplinary team from the USA Savannah River National laboratory is providing technical assistance to IPEN in this performance assessment.

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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 26967

    SANTOS, VINICIUS T. dos; SANTOS, GIVANILDO A. dos; NAKAMOTO, FRANCISCO Y.; SILVA, MARCIO R. da; FRANCO, ANTONIO T.R.; COUTO, ANTONIO A. . Influência das variáveis térmicas de solidificação na microestrutura e dureza da liga bronze alumínio níquel CuAl10Ni5Fe5 / Influence of thermal variables of solidification on the microstructure and hardness of nickel aluminum bronze alloy CuAl10Ni5Fe5. In: CONGRESSO BRASILEIRO DE ENGENHARIA DE FABRICAÇÃO, 9., 26-29 de junho, 2017, Joinville, SC. Anais... Rio de Janeiro, RJ: Associação Brasileira de Engenharia e Ciências Mecânicas, 2017.

    Abstract: O objetivo deste trabalho é obter correlações entre a microestrutura e dureza da liga Bronze Alumínio Níquel CuAl10Ni5Fe5 em função das variáveis térmicas de solidificação. Estas variáveis são responsáveis pela formação das fases e intermetálicos presentes no Bronze Alumínio Níquel, os quais interferem diretamente nas propriedades mecânicas do material. A liga CuAl10Ni5Fe5 foi solidificada em um dispositivo com sistema ascendente sob condições não-estacionárias de fluxo de calor. O calor foi extraído direcionalmente através de uma base de aço ABNT 1020 refrigerada a água. No que diz respeito à análise da microestrutura, utilizou-se microscopia eletrônica de varredura, permitindo a verificação das morfologias das fases e intermetálicos. As variáveis térmicas de solidificação geram resultados referentes à velocidade de deslocamento da isoterma liquidus e à taxa de resfriamento. A propriedade mecânica foi avaliada por meio de ensaio de dureza em toda extensão longitudinal da peça solidificada, a qual apresenta a formação das fases e intermetálicos formados por meio das condições de solidificação impostas pelo sistema metal/molde. A microestrutura e dureza são correlacionadas com as variáveis térmicas de solidificação, enfatizando a importância das taxas de resfriamento na formação das fases e intermetálicos da liga CuAl10Ni5Fe5. O resultado deste trabalho demonstra que, quanto maior a taxa de resfriamento, maior é o resultado obtido de dureza.

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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 26961

    SANTOS, CAMILA F.R.T.T. ; SILVA, TATIANE B. de S.C. da ; COTRIM, MARYCEL E.B. ; PIRES, MARIA A.F. . Fatores de emissão atmosférica e análise de significância aplicada na gestão da qualidade do ar no campus do IPEN/CNEN-SP / Atmospheric emission factors and significance analysis applied to the air quality management in the IPEN / CNEN-SP campus. In: ENCONTRO INTERNACIONAL SOBRE GESTÃO EMPRESARIAL E MEIO AMBIENTE, 18., 5-6 de dezembro, 2016, São Paulo, SP. Anais... São Paulo, SP: Faculdade de Economia, Administração e Contabilidade da Universidade de São Paulo - FEA USP, 2016.

    Abstract: Devido ao compromisso com a melhoria do meio ambiente, aliado às crescentes exigências dos órgãos ambientais, e a necessidade de identificar a contribuição de cada atividade/processo desenvolvido em institutos de pesquisas, quanto ao impacto destes à qualidade do ar, este trabalho tem a finalidade de desenvolver um modelo de inventário e aplicar uma metodologia de cálculo, que permita estimar a emissão de poluentes atmosféricos, decorrentes das atividades dos centros de pesquisa e desenvolvimento do Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP). O estudo foi motivado pela ausência de metodologias de cálculo de emissões atmosféricas específicas para fontes fixas como capelas de exaustão. Para a elaboração dos cálculos foram adotados os fatores de emissão e a equação descrita na AP-42 da EPAEnvironmental Protetion Agency. Foram utilizadas como abordagens de cálculo de emissões: a) Mensuração direta (por meio do inventário de emissões atmosféricas); e b) Estimativa de emissões (utilizando estimativa da taxa de emissão calculada a partir do fator de emissão apropriado). Como produto final obteve-se um inventário de emissões atmosféricas de fontes fixas da instituição e estimou-se a emissão atmosférica do Centro de Química e Meio Ambiente (CQMA) a fim de estabelecer de forma efetiva o Programa de Monitoramento e Controle de Emissões Atmosféricas (PMEA – IPEN), servindo de base para outras instituições de Pesquisa, Desenvolvimento & Inovação.

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

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

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

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

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


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