REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

 

 

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

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

 

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  • IPEN-DOC 25644

    GARCIA, RAFAEL H.L. . Caracterização e quantificação de fases em ligas de urânio-silício para aplicação como combustível nuclear / Characterization and quantification of crystalline phases of uranium-silicon alloys for nuclear fuel . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 203 p. Orientador: Nelson Batista de Lima. Coorientador: Adonis Marcelo Saliba Silva. DOI: 10.11606/T.85.2019.tde-07032019-090637

    Abstract: A segurança da operação de reatores nucleares depende dos materiais envolvidos em sua construção, pois são submetidos a variações de temperaturas em ambiente corrosivo e avarias causadas por partículas de alta energia. O combustível, que proporciona energia para o reator, possui vida útil muito menor, mas é submetido às mesmas condições. Dentre as ligas de urânio, o U3Si2 é bastante utilizado em reatores de pesquisa, dada a elevada densidade de urânio, boa condutividade térmica e resistência à amorfização induzida por radiação, ao inchamento e à propagação de trincas. Porém, no processo de fabricação da liga U-Si geralmente são formadas duas ou mais fases cristalinas, com comportamentos distintos sob irradiação. Por esse motivo, a especificação do pó de siliceto de urânio utilizado no reator IEA-R1 do IPEN, e do RMB (Reator Multipropósito Brasileiro) é de, pelo menos, 80% em massa de U3Si2. No entanto, as técnicas de caracterização atualmente utilizadas no controle de qualidade não permitem quantificar as fases cristalinas diretamente. Assim, esse trabalho propõe a utilização da difração de raios X (DRX), alinhada a refinamento pelo método de Rietveld para caracterização do pó de siliceto. Para tal, foram produzidas ligas de urânio contendo 33 a 67 mol% de silício, e técnicas de moagem e ajustes de refinamento foram testados. O método desenvolvido inclui cominuição em moinho vibratório e DRX com refinamento automatizado dos dados, permitindo a quantificação das fases cristalinas de maneira confiável, rápida e com mínima interferência do operador. Os resultados obtidos foram corroborados com os de técnicas como análise de imagem obtida por microscópio eletrônica de varredura (MEV), densidade e análises elementares de U e Si.

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  • IPEN-DOC 25643

    SOMESSARI, SAMIR L. . Desenvolvimento de um sistema automatizado para controle operacional do acelerador industrial de elétrons Cockcroft-Walton / Automated system development for operating control for a Cockcroft-Walton industrial electron beam accelerator . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 129 p. Orientador: Wilson Aparecido Parejo Calvo.

    Abstract: Os aceleradores de feixes de elétrons são utiizados em muitas aplicações, tais como pesquisa em física básica, química, medicina, biologia molecular, microeletrônica, agricultura e indústria, dentre outras. Na maioria dos aceleradores, por meio de aquecimento do filamento de tungstênio e da alta tensão via gerador Cockcroft-Walton, os elétrons passam por um campo elétrico na câmara em vácuo e são acelerados de acordo com a alta tensão aplicada, transferindo energia aos elétrons. Para fins industriais, um dos equipamentos mais utilizados é o Acelerador Industrial de Elétrons Dynamitron®. No IPEN-CNEN/ SP, instalou-se um acelerador de feixe de elétrons Dynamitron®, fabricado pela RDI Radiation Dynamics Inc., modelo DC1500/25/4, em 1978. A tecnologia analógica aplicada nesse acelerador industrial de elétrons data de 1960 e 1970. Assim, além da tecnologia de controle operacional obsoleta, não há mais peças e componentes sobressalentes originais, fornecidos pelo fabricante (RDI) ao equipamento. O objetivo deste trabalho foi desenvolvido um sistema automatizado para controle operacional do acelerador industrial de elétrons Cockcroft-Walton de 37,5 kW (1,5 MeV e 25 mA) no Instituto.

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  • IPEN-DOC 25642

    MANTECON, JAVIER G. . Evaluation of mechanical stability of nuclear fuel plates under axial flow conditions / Avaliação de estabilidade mecânica de placas de combustível nuclear sob condições de fluxo axial . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 102 p. Orientador: Miguel Mattar Neto.

    Abstract: Several nuclear research reactors use or are planned with cores containing flat-plate- type fuel elements. The nuclear fuel is contained in parallel plates that are separated by narrow channels through which the fluid flows to remove the heat generated by fission reactions. One of the problems of this fuel element design is the mechanical stability of the fuel plates. High-velocity coolant flowing through the channels can cause large deflections of these plates leading to local overheating, structural failure or plate collapse. As a consequence, the safe operation of the reactor may be affected. In this work, a numerical fluid-structure interaction study was conducted for evaluating the mechanical stability of nuclear fuel plates under axial flow conditions. Five different cases were analyzed. In all cases, the system consisted of two fuel plates bounded by fluid channels but, in case 5, a support comb at the leading edge of the plates was inserted. The pressure loadings caused by the fluid flow were calculated using a Computational Fluid Dynamics model created with ANSYS CFX. The structural response was determined by means of a Finite Element Analysis model generated with ANSYS Mechanical. Both models were coupled using the two-way fluid-structure interaction approach. The results from Case 1 allowed proposing a methodology to predict the critical velocity of the assembly without an inlet support comb. The maximum deflection of the plates was detected at their leading edges. It was detected that, for flow rates in the channels less than a certain value, the maximum deflection increased linearly with the square of the coolant velocity. In contrast, for greater flow rates, a nonlinear behavior was observed. Therefore, that fluid velocity was identified as the critical velocity of the system. Besides, above the critical velocity, an extra deflection peak was observed near the trailing edge of the plates. In cases 2, 3 and 4, the influence of manufacturing deviations and the change of materials properties due to the increment of temperature on the critical velocity was investigated. With these conditions, the critical velocity of the system was found at lower values. Lastly, in Case 5, the effectiveness of using a support comb at the leading edge of the plates was investigated. The results showed that the static divergence at the inlet end is effectively eliminated with the installation of the comb. In addition, the flow-induced deflections along the length of the plates were significantly diminished with the comb.

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  • IPEN-DOC 25641

    YAMAZAKI, IONE M. . Padronização em sistema primário por coincidências 4πβ-γ e determinação das intensidades de emissão gama por decaimento dos radionuclídeos Cu-64 e Ho-166 / Primary standardization of 64Cu and 166Ho radionuclides in the 4πβ(PC)-γ coincidence system and determination of its gamma-ray emission probability per decay . 2019. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 161 p. Orientador: Marina Fallone Koskinas. Coorientador: Mauro da Silva Dias.

    Abstract: O Laboratório de Metrologia Nuclear (LMN) do Instituto de Pesquisas Energéticas e Nucleares (IPEN) realizou a padronização primária dos radionuclídeos 64Cu e 166Ho. Esses radioisótopos são utilizados na Medicina Nuclear em investigações diagnósticas e em radioterapia. A atividade absoluta foi determinada utilizando o método de coincidências 4πβ(PC)- γ associado à técnica de extrapolação de eficiência. Para isto, foram utilizados um contador proporcional em geometria 4π acoplado ao um contador de cintilação NaI (Tl). Para a padronização do 64Cu foram utilizados dois sistemas para registro de dados: sistema TAC e sistema SCS. No sistema TAC é utilizado o módulo Time to Amplitude Converter (TAC) associado a um analisador multicanal, sendo que a eficiência do detector 4πPC foi variada por meio de absorvedores externos e foi aplicado fator de correção para as eficiências beta denominado fator Kawada. No sistema SCS (Software Coincidence System) o registro dos eventos foi feito por meio da digitalização dos pulsos, a eficiência do detector 4πPC foi variada por discriminação eletrônica e a atividade foi obtida pela extrapolação biparamétrica. A padronização do 166Ho em sistema de coincidências 4πβ(PC)- γ foi realizada utilizando o sistema de aquisição de dados por software, SCS (Software Coincidence System). Para determinação das probabilidade de emissão gama dos radionuclídeos foi utilizado um espectrômetro gama HPGe calibrado com ampolas padrão de 152Eu, 60Co, 133Ba, 137Cs e 241Am, calibradas no sistema primário 4πβ(PC)- γ. A probabilidade de emissão gama por decaimento do fóton de 1345,7 keV do 64Cu obtida foi de 0,472 (10) % apresentando um bom acordo com os dados da literatura. A probabilidade de emissão gama por decaimento do fóton gama de 1379,45 keV do 166Ho foi de 0,936 (4) %. Por meio destas medidas foi possível também a determinação das intensidades relativas de outros fótons emitidos por este radionuclídeo. Os resultados obtidos foram concordantes com a literatura dentro da incerteza experimental.

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  • IPEN-DOC 25640

    MORAIS, VINICIUS R. de . Processos de síntese de pós cerâmicos a base de diopsita dopada com disprósio para materiais luminescentes emissores de luz branca / Synthesis processes of ceramic powders based on Dy-doped diopside for the white-emitting luminescent materials . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 74 p. Orientador: Chieko Yamagata.

    Abstract: Fósforos à base de diopsita (CaMgSi2O6) dopada com disprósio (Dy3+) foram preparados a partir da combinação dos métodos sol-gel e coprecipitação. Foram adotados três procedimentos diferentes para síntese, nos quais gel de sílica foi obtido a partir de solução de Na2SiO3 e a ele foi adicionado precipitados de hidróxidos de cálcio, magnésio e disprósio. A etapa de lavagem da mistura dos precipitados foi estudada para evitar dissolução dos hidróxidos de cálcio e magnésio. O produto lavado, após calcinação a 900°C por períodos de 1 a 3 horas, foi obtido o pó cerâmico apresentando diopsita como fase principal, confirmada por análise de DRX. O espectro de emissão de fotoluminescência do pó cerâmico apresentou os picos característicos do Dy3+, localizados nas regiões do azul e do amarelo. A partir da relação entre as intensidades desses picos, é possível obter luz branca. Foram variadas as concentrações de dopagem de disprósio nas amostras. Aquelas com concentrações de até 0,5%mol em disprósio foram as que apresentaram emissões mais próximas do branco, segundo o diagrama CIE. Foi observado um comportamento interessante da relação entre a luminescência em função do teor de dopagem de disprósio. Verificou-se que o aumento do teor de disprósio acarreta diminuição da intensidade de emissão até certo ponto onde ela volta a aumentar. As curvas de persistência luminescente apresentaram decaimento da ordem de décimos de segundos, o que pode indicar que o material não apresenta defeitos em quantidade ou profundidade suficiente para aplicações como fósforo persistente.

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  • IPEN-DOC 25639

    SANTOS, RICARDO S. dos . Estudo do crescimento da concentração de hexafluoreto de enxofre (SF6) nas regiões norte e nordeste do Brasil / Study of sulfur hexafluoride concentration enhancement in brazilian north and northeast regions . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 77 p. Orientador: Luciana Vanni Gatti.

    Abstract: O hexafluoreto de enxofre (SF6) não figura como um dos gases de efeito estufa com as maiores concentrações no planeta Terra, no entanto, é um gás com um potencial de aquecimento global extremamente grande. Portanto, uma quantidade relativamente pequena pode ter um impacto importante nas mudanças climáticas do globo. Ele é um gás antropogênico, suas emissões são provenientes, principalmente, na distribuição de energia elétrica; é o gás preferido da indústria para interrupção de corrente elétrica e como isolamento de segurança na transmissão e distribuição de eletricidade. Ele é utilizado em disjuntores e equipamentos de alta tensão e na indústria de fundição de magnésio. Este estudo foi desenvolvido com o objetivo de elucidar se existe uma contribuição da Bacia Amazônica, e costa Norte e Nordeste brasileiras nas emissões deste gás, além de mostrar um amplo banco de dados de suas concentrações ao longo do tempo, com início das medições deste o ano 2000. A quantificação do SF6 foi realizada por meio da coleta do ar atmosférico utilizando aviões de pequeno porte que descreveram um perfil vertical em quatro locais, estrategicamente posicionados na Bacia Amazônica, e utilizando sistemas semiautomáticos de coleta de ar em 17 ou 12 altitudes diferentes, juntamente com coletas em 3 locais nas costas Norte e Nordeste brasileiras, com armazenamento das amostras em frascos de vidro. Para a comparação da concentração com estações globais, foram utilizadas as concentrações medidas pela NOAA na Ilha de Ascension e Barbados. Não foi encontrado um caráter emissor da Amazônia e da costa brasileira. Os resultados de uma maneira geral mostram a ocorrência de um crescimento nas concentrações médias obtidas em todos os locais de amostragem com o passar dos anos, acompanhando o crescimento mundial.

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  • IPEN-DOC 25648

    SENNA, ROQUE M. de; SANTOS, THAIS; SENNA, HENRIQUE; LINARDI, MARCELO . Determinação experimental da curva de polarização de uma célula a combustível tipo PEM. In: VOIGT, CARMEN L. (Org.). Impactos das tecnologias na engenharia química 3. Ponta Grossa, PR: Atena, 2019. p. 178-186, v. 3, cap. 22. DOI: 10.22533/at.ed.31919010422

    Observação: e-book

    Abstract: A geração de energia elétrica se apresenta como um grande desafio para a humanidade, devido ao seu enorme potencial poluidor, notadamente quando advinda de combustíveis fósseis. No mundo, em 2013, como mostrado no BEN 2016, apenas 13,5% da matriz energética compunha-se de combustíveis renováveis, sendo no Brasil 41,2%. Baseado nessas estatísticas pode-se afirmar que a produção de energia no Brasil ainda é predominante de combustíveis fósseis. Uma das alternativas que merece destaque especial é a tecnologia de células a combustível (CAC), pois são dispositivos sustentáveis e não poluentes que oxidam eletroquimicamente o combustível, em geral hidrogênio, gerando energia elétrica e calor. Pretende-se com esse trabalho, mostrar os procedimentos para ensaiar uma CAC unitária, de eletrólito sólido ETEK_HP, composto por uma membrana de náfion (PTFE), de espessura de 115 μm, sendo o eletrodo constituído por catalisador de platina, com carga de 0,4mg/cm² no ânodo, e 0,6mg/cm² no cátodo, suportados em carbono. O ponto ótimo de operação da CAC pela eficiência do MEA foi em 433 mV@1120 mA, de característica linear, e não está sujeito, significativamente, aos fenômenos de ativação e transferência de massa. Nota-se que entre 365 mV e 558 mV, a densidade foi acima de 0,45 W/cm², e consequentemente a potência da CAC acima de 11 W. O consumo de oxigênio e hidrogênio foi mais eficiente acima de 800 mV.

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  • IPEN-DOC 25638

    GASPAR, RENATO R. . Desenvolvimento do sistema de potência elétrica em uma unidade móvel de irradiação por feixe de elétrons para tratamento de águas residuárias e efluentes industriais / Developing an electrical power system of a mobile electron beam accelerator to treatment of industrial wastewaters and effluents . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 64 p. Orientador: Wilson Aparecido Parejo Calvo.

    Abstract: O tratamento de águas residuárias e efluentes industriais por irradiação com feixe de elétrons é uma técnica promissora, porém pouco difundida em território Brasileiro. O projeto e a construção de uma unidade móvel contendo um acelerador industrial de elétrons de 700 keV e 20 kW, pelo Instituto de Pesquisas Energéticas e Nucleares (IPEN), é inovador para demonstrar os efeitos e resultados positivos dessa tecnologia. O propósito é deslocar a unidade móvel às diversas empresas com interesse em tratamento dos resíduos líquidos, conectar-se ao sistema elétrico da mesma e iniciar o processo de tratamento por ionização, por meio da irradiação com feixe de elétrons. A conexão da unidade móvel ao sistema elétrico local pode representar um desafio, pela grande diversidade de tensões e distâncias envolvidas, e também pelas grandes injeções de conteúdo harmônico gerado pelo acelerador de elétron que podem afetar as cargas do sistema industrial, comumente sensíveis. Neste trabalho realizou-se uma análise do sistema de potência da unidade móvel, quanto à capacidade de interrupção, seletividade da proteção e níveis de curto-circuito adequados de forma a assegurar uma maior confiabilidade na operação. Ao final, projetou-se e construiu-se o painel elétrico de controle da unidade móvel de irradiação. Além disso, na obtenção de parâmetros operacionais à unidade móvel, realizaram-se simulações e medições no acelerador industrial de elétrons de 1,5 MeV e 37,5 kW, instalado no Laboratório de Fontes Intensas de Radiação, do Centro de Tecnologia das Radiações, as quais demonstraram a necessidade da inserção de um filtro para redução dos índices de distorção nos harmônicos dessa instalação radiativa fixa no IPEN.

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  • IPEN-DOC 25637

    NAGAI, MARIA L.E. . Estudo da utilização da radiação ionizante para preservação e conservação de filmes fotográficos e cinematográficos / Study of the use of ionizing radiation for the preservation and conservation of photographic and cinematographic films . 2019. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 131 p. Orientador: Pablo Antonio Vasquez Salvador.

    Abstract: O Irradiador Multipropósito de Cobalto-60 do Centro de Tecnologia das Radiações, CTR-IPEN-CNEN/SP, tem tratado diversos acervos bibliográficos da Universidade de São Paulo, USP, para desinfestação e desinfecção de materiais contaminados com insetos e fungos. A irradiação com feixe de elétrons também permite processar materiais com maior velocidade, porém com pouca penetração. Muitos desses acervos bibliográficos incluem filmes fotográficos e cinematográficos em suporte de triacetato de celulose. Considerando-se a dificuldade no seu armazenamento adequado, um dos problemas decorrentes mais comuns é a contaminação por fungos nos acervos e a degradação físico-química chamada "síndrome do vinagre", em que ocorre a desacetilação da cadeia polimérica. O objetivo deste trabalho foi estudar o efeito da radiação ionizante, raios gama e feixe de elétrons, e caracterizar amostras de filmes fotográficos e cinematográficos irradiados e não irradiados. Adicionalmente, determinar o intervalo de dose de radiação aceitável e segura que promova a eliminação dos fungos e não altere a estrutura das matrizes poliméricas. Estudar a possibilidade da dose ideal de radiação ionizante para o efeito da reticulação do suporte nos filmes. Os filmes selecionados foram caracterizados por espectroscopia de infravermelho (FTIR-ATR) e microscopia eletrônica de varredura (FEGSEM-EDS). Em seguida, aplicaram-se doses entre 2 kGy e 200 kGy de raios gama e feixe de elétrons, nas amostras dos filmes, que foram analisadas por técnicas de espectroscopia UV-visível (UV-vis), microscopia eletrônica de varredura (FEGSEM), termogravimetria (TG) e calorimetria diferencial de varredura (DSC). Os resultados demonstraram que a desinfecção por radiação gama e feixe de elétrons pode ser realizada com segurança, aplicando-se a dose de desinfecção entre 6 kGy e 10 kGy, sem que ocorra alteração ou modificação das propriedades principais dos materiais constitutivos. A irradiação com raios gama e feixe de elétrons com a dose absorvida de 50 kGy constitui-se como uma alternativa para tratar filmes afetados pela síndrome do vinagre e prolongar a vida útil dos bens culturais.

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  • IPEN-DOC 25636

    FERREIRA, AMAURI A. . Ressonador laser em anel de alta potência e frequência única de Nd:YAG / Nd:YAG single frequency high power laser ring resonator . 2018. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 67 p. Orientador: Niklaus Ursus Wetter.

    Abstract: Para a espectroscopia de alta resolução e metrologia óptica em geral, é desejável um laser com linha espectral estável e de alta potência de saída para bombear diferentes tipos de ressonadores, como osciladores paramétricos óticos (OPO Optical Parametric Oscillator). Os lasers de frequência única disponíveis estão no alcance de potência de saída de 10 Watts, enquanto que, dependendo da aplicação e do tipo de OPO, é desejável uma maior potência (> 20 W). Neste trabalho foi desenvolvido um laser de frequência única e alta potência com base em módulos de bombeio por diodos e tendo como meio ativo o granada de alumínio de ítrio dopado com neodímio (Nd:YAG). Dois bastões de Nd:YAG bombeados transversalmente por diodo, foram utilizadas em uma configuração de ressonador em anel com saída polarizada de onda continua (CW continuous-wave), qualidade de feixe modo transversal eletromagnético (TEM00) e potência de saída de 105,2 W. A potência de saída alcançada é, a nosso entender, a mais alta para lasers em anel no modo fundamental transversal polarizado contínuo usando módulos Nd:YAG comuns com bombeamento lateral. O ressonador permitiu a sintonização de potência em uma grande faixa dinâmica e obteve excelente qualidade de feixe, usando uma placa de meia onda entre os dois bastões para compensação de birrefringência. A operação de frequência única foi alcançada usando cristal de granada de térbio-gálio (TGG-Terbium Gallium Garnet), dois imãs e um etalon, com uma potência de saída de 51,60 W e uma largura a meia altura da curva (FWHM) espectral de aproximadamente 17 MHz.

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  • IPEN-DOC 25635

    MUNHOZ JUNIOR, ANTONIO H.; PACHECO, CAROLINE V.; MELO, HENRIQUE T.T.S.; PERES, RENATO M.; SILVA, LEONARDO G. de A. e ; MIRANDA, LEILA F. de; ROMERO FILHO, MARCOS. Characterization of a composite of high-impact polystyrene, pseudoboehmite and graphene oxide. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 511-522, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_51

    Abstract: The application of a composite material of pseudoboehmite, polystyrene and graphene oxide was studied. The present work is the synthesis and characterization of high-impact polystyrene (HIPS) nanocomposite, with pseudoboehmite (PSB) and graphene oxide. Pseudoboehmite particles with nanometric dimensions were obtained by sol-gel process. The composites were characterized by mechanical tests (tensile strength, flexural strength, Izod Impact, Shore D Hardness), thermal (Flow index, temperature of thermal deflection under load-HDT, Vicat softening temperature, differential tests thermal analyses and thermogravimetric analysis) and morphologically by Scanning Electron Microscopy (SEM). The results obtained were compared with HIPS matrix properties, without PSB and graphene oxide addition. From the thermal analyzes, composite samples showed higher decomposition temperatures compared to pure high-impact polystyrene especially in the thermogravimetric analysis results, showing a considerable increase in the temperature at which material decomposition begins (322 °C for pure high-impact polystyrene and 380 °C for the composite).

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  • IPEN-DOC 25634

    MUNHOZ JUNIOR, ANTONIO H.; GALHARDO, GUSTAVO F.; ORTEGA, FERNANDO dos S.; LIMA, NELSON B. de ; MORAES, DENISON A.; MIRANDA, LEILA F. de; VALENZUELA-DIAZ, FRANCISCO R.. Alpha-alumina synthesis using gamma-alumina powders. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 441-451, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_44

    Abstract: Alpha-alumina is a ceramic material with applications as a biomaterial in femoral prostheses and teeth. The study of the influence of the precursor powder on the microstructure and mechanical properties of the alumina obtained is extremely important for the use of the same as biomaterials. Other applications of alpha-alumina industrially are in obtaining parts used at high temperatures and in chemically aggressive environments. Alpha-alumina can be synthesized from different raw materials resulting in ceramic products with different microstructures and consequently with diverse mechanical resistance. The synthesis of alpha-alumina pieces obtained from gamma-alumina powders was studied in order to verify the mechanical properties of the sintered material. The addition of graphene oxide in the gamma-alumina powder was also studied. To evaluate the mechanical strength of the obtained alpha-alumina specimens and to correlate the mechanical resistance with the precursor used in alpha-alumina synthesis it was used three -point bend strength testing.

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  • IPEN-DOC 25633

    POVEDA, PATRICIA N.S. ; SILVA, LEONARDO G.A. e . Study of the influence of organic peroxide and elastomeric modifier in the mechanical and flow properties of the recycled polypropylene. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 787-792, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_79

    Abstract: Plastics have been replacing other traditional materials such as wood, metal and glass over the past decades due to its versatility in properties, processability, and cost. Polypropylene can be highlighted as one of the main thermoplastics used in industry since it presents properties suitable for various applications, combining density, cost, availability, and ease of molding. By considering the mechanical recycling of post-consumer or post-industrial material, difficulty in flowability is observed, which demands modification to promote processability. This work used the traditional solution for flow modification (peroxide) and elastomeric modifier to evaluate the impact of these additives on the mechanical and flow properties of recycled polypropylene by tensile strength, melt index and spiral flow analyses. Although the modified sample with organic peroxide had a higher melt flow index, the mechanical resistance was lower than the elastomeric modifier, which showed good performance in the material flow during processing according to spiral flow analysis.

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  • IPEN-DOC 25632

    MIRANDA, LEILA F.; GOMES, PAULO V.C.; ALMEIDA, FABIO J.M. de; SILVA, LEONARDO G.A. e ; MUNHOZ JUNIOR, ANTONIO H.; MASSON, TEREZINHA J.. Study of the electrical properties of rGO obtained by different GO reduction methods. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 773-785, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_78

    Abstract: Thiswork aimed at the synthesis of graphene oxide (GO) and its reduction in reduced graphene oxide (rGO), as well as the characterization of the obtained GO and of each of the products of the various GO reduction methods. The characteristics of the GO and rGO samples were compared in order to study the results for each reduction method. Graphene oxide was synthesized, from the modified Hummers methodology, using powdered graphite and subsequently reduced to rGO by different methods (chemical method: reduction with hydrazine and carbon–C-dots nanoparticles, and physical: ultrasound). The samples obtained from graphene oxide and reduced graphene oxide were characterized electrically and microstructurally. The results showed that the samples of GO reduced with hydrazine were those that obtained the best results of conductivity and good restructuring of the sp2 hybridization, followed by the carbon nanoparticles and ultrasound.

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  • IPEN-DOC 25631

    BARTOLOMEI, SUELLEN S.; MOURA, ESPERIDIANA A.B. de ; WIEBECK, HELIO. Recycled gypsum particles incorporation in recycled expanded polystyrene by biodegradable solvent: preparation and characterization. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 757-763, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_76

    Abstract: The recycling of expanded polystyrene (EPS) by the use of ethyl acetate, a biodegradable solvent is an alternative by the regular recycling process. Due to the fragility of the polystyrene (PS), 2 wt% of glycerol was added in the recycled expanded polystyrene (REPS) to increase the mobility of the polymer chains reducing the brittleness of this material. As a dispersed phase was used recycled gypsum from construction waste. 5, 10, and 15 wt% of recycled gypsum were used to obtain composites by melt extrusion.Virgin PS, RPS, RPS/Glycerol, and RPS/Glycerol/Gypsum composites were characterized by Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), Field Emission Scanning Electron Microscopy (FEGSEM), and flammability test. The results showed that the addition of glycerin plasticized RPS and Gypsum particles improved the thermal stability. In the flammability test, the samples containing gypsum do not extinguish the flames of the material, this phenomenon was not observed in the other compositions.

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  • IPEN-DOC 25630

    CORREIA, SABRINA A.; CRUZ, PEDRO V. ; RODRIGUES, TASSON C.; MONTEIRO, ALEX ; DIAZ, FRANCISCO R.V.; MOURA, ESPERIDIANA A.B. . Production and characterization of a hybrid composite of polypropylene reinforced with piassava (Attalea funifera Martius) fiber and light green clay. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 735-746, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_74

    Abstract: Waste materials have been frequently used as reinforcing materials, to obtain a composite with better properties. Piassava palm is native to the state of Bahia (Brazil) and its fiber, piassava fiber (PF) is awaste material frequently used for industrial and domestic brooms, industrial brushes, carpets, and roofs. The light green clay (LGC) is a natural smectite Brazilian clay from the state of Paraiba. This work aims to produce and evaluate the advantages of this new product achieved by the inclusion of these two natural materials into polypropylene (PP) matrix. A melting extrusion process, using a twin-screw extruder and injection molding machine was used to obtain PP/LGC (97/3 wt%), PP/PF (90/10 wt%) and PP/LGC/PF (87/3/10 wt%) composites. The materials were characterized by mechanical tests, TG, DSC, SEM, and XRD analysis.

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  • IPEN-DOC 25629

    FRANCISCO, DANAE L. ; PAIVA, LUCILENE B. de; ALDEIA, WAGNER; LUGAO, ADEMAR B. ; MOURA, ESPERIDIANA A.B. . Investigation on mechanical behaviors of polyamide 11 reinforced with halloysite nanotubes. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 693-701, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_69

    Abstract: The inorganic halloysite nanotubes (HNTs) are a promising type of natural occurring filler for polymers. Its characteristics such as high aspect ratio (10–50), small size, and high strength (elastic modulus—140 GPa) suggest that HNTs have a potential use in high-performance polymer nanocomposites. Compared to other nanoclays and nanosilica, the relatively low content of hydroxyl groups on their surfaces makes HNTs relatively hydrophobic, although, sometimes, this is not sufficient for guaranty a good interfacial adhesion in composite systems. In the present study, halloysite nanotubes were incorporated in a polyamide 11 (PA11) matrix by melt extrusion, using a twin-screw extruder and injection molding machine. The neat PA11 and PA11/HNT nanocomposites were characterized by mechanical tests (tensile, flexural and impact tests), and the correlation between properties were discussed.

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  • IPEN-DOC 25628

    MESQUITA, ANDERSON dos S. ; CAVALCANTE, IAN T. ; SILVA, LEONARDO G. de A. e . Electron beam effect on the thermal and mechanical properties analysis of DGEBA/EPDM compound. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 637-646, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_63

    Abstract: The aim of this work is to obtain, characterize and irradiate the DGEBA/EPDM compound and compare their thermal and mechanical properties with a non-irradiated DGEBA/EPDM compound. The DGEBA/EPDM compound may be used to cover other materials such as polymers and protect them against high thermal conditions and mechanical effort. The compounds have 0.0, 25.0 and 50.0 wt% of DGEBA. In addition, the compounds were irradiated at 30 and 60 kGy at a dose rate 22.41 kGy/s. The thermal properties (DMA and TGA) and mechanical analysis (tensile strength and elongation at break) were performed. In conclusion, the irradiated DGEBA/EPDM compounds may be used for several applications due to the improvement in their mechanical and thermal properties. Their properties are satisfactory for application that requires stronger material.

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  • IPEN-DOC 25627

    SALES, J.N. ; POVEDA, P.N.S. ; ORTIZ, A. ; VALENZUELA-DIAZ, F.R.; SILVA, L.A. . Effect study of the incorporation of the Green Lake clay in the polypropylene homopolymer properties. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 629-636, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_62

    Abstract: The advancement of technology has demanded the development of materials with increasingly lighter and more resistant properties. The development of nanocomposites first started in the mid-80s and contributed for obtaining materials with excellent properties. In this work, Green Lake clay was organophilized and incorporated into a commercial homopolymer polypropylene. The efficiency of organophilization was confirmed by water swelling analysis and, later, by Xray diffraction (XRD) analysis. Composites at 0.5, 1.0 and 2% by weight of clay/polypropylene were prepared by double screw extrusion. The properties of the composite were evaluated by means of Charpy impact resistance, tensile strength at rupture, thermogravimetric analysis (TGA). Crystallinity index was determined by differential scanning calorimetry (DSC). The organophilization processwas efficient, the thermogravimetric analysis showed that there was no decrease in the thermal stability of the composites when compared to pure polypropylene, and the results of the Charpy impact resistance were equivalent when compared to the commercial nucleant composites.

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  • IPEN-DOC 25626

    ROMANO, REBECA da S.G. ; OLIANI, WASHINGTON L. ; KUMAR, VIJAYA R.; PARRA, DUCLERC F. ; LUGAO, ADEMAR B. . Differences in properties of pro-degradant added PP and gamma-irradiated PP under environmental aging. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 591-603, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_59

    Abstract: Polypropylene (PP) is used for different sectors of the industry and in consequence produces a large amount of waste discarded at landfills causing serious environmental impacts. Controlled degradation of PP can be achieved by exposing the polymers to defined parameters, such as absorbed radiation dose, weather, oxygen, etc. The aim of this study was to compare two methods of accelerated degradation: gamma irradiation of PP 20 kGy and the incorporation of the commercial pro-degradant d2w® (1 wt%) in PP. Dumbbell samples were manufactured by the injection process and exposed to the environment aging for 90 days. Structural changes in PP macromolecules are created upon exposure to ionizing radiation such as main chain scission, crosslinking and peroxidation (in presence of air). Differential scanning calorimetry (DSC), thermogravimetric analysis (TG), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), X-ray fluorescence, Fourier-transformed infrared spectroscopy (FTIR) and mechanical tests characterized the samples. The samples previously irradiated, PP 20 kGy, after natural aging showed higher oxidation and presence of surface cracks than the PP d2w®. They also showed presence of carbonyl groups and decrease of melting temperature corroborating with oxo-degradation.

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  • IPEN-DOC 25625

    REIS, PEDRO R.S. ; SANTANA, JULYANA G. ; OLIVEIRA, RENE R. ; RANGARI, VIJAYA K.; LOURENÇO, FELIPE R.; MOURA, ESPERIDIANA A.B. . Development of biocomposite materials from biodegradable polymer and bio-hydroxyapatite derived from eggshells for biomedical applications. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 571-581, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_57

    Abstract: Nowadays, significant advances have been made in the development of biodegradable polymeric materials for biomedical applications. This study aims to prepare and characterize composite materials based on PLA/PBAT, a biodegradable polymer blend, reinforced with bio-hydroxyapatite (bio-HAp). First, bio-HAp was obtained from eggshell residues by the wet precipitation method. PLA/PBAT blend with 1.5 wt% of bio-HAp was prepared by melt extrusion and injection molding process. Part of composite samples was irradiated with gamma radiation dose of 25 kGy, at room temperature and presence of air. The effects of the bio-HAp addition into the biodegradable blend were investigated by mechanical tests, XRD, DSC, FESEM, and cytotoxicity “in vitro” analysis and the correlation between the properties was discussed. In addition, the microbiological tests were carried out at irradiated and non-irradiated composite samples in order to evaluate the efficiency of the radiation dose of 25 kGy at composite materials sterilization.

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  • IPEN-DOC 25624

    MONTEIRO, ALEX S. ; BARREIRA, DAILI A.S. ; BARTOLOMEI, SUELLEN S. ; OLIVEIRA, RENE R. ; MOURA, ESPERIDIANA A.B. de . Comparative study of the use of rice husk ashes and graphite as fillers in polypropylene matrix composites. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 561-570, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_56

    Abstract: In recent years, carbonaceous materials have been widely studied for polymer composite applications due to its capability to improve the engineering properties of the polymeric matrix. Among various carbonaceous fillers, carbon nanotube, graphene, and graphite promise to be a suitable reinforcement of polymers. Rice husk ash (RHA), a large residue rich in carbon and silica produced by the burning of rice husk offers also an immense potential as a carbonaceous filler for polymer composites on account of its lowcost, lowdensity, high strength and elastic modulus, no health risks, and renewability. This work aims at studying the effects of RHA and graphite as fillers in polypropylene (PP) matrix composites. The composites PP/RHA and PP/graphite were produced by melting extrusion process. The materials obtained were subjected to mechanical tests, XRD, TG, and FEG-SEM analyses. Comparison studies between neat PP properties and its composites were carried out.

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  • IPEN-DOC 25623

    MIRANDA, LEILA F. de; MUNHOZ JUNIOR, ANTONIO H.; MASSON, TEREZINHA J.; SILVA, LEONARDO G. de A. e ; FRIEHE, KARL. Characterization of antistatic packaging based on PET/rGO. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 523-534, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_52

    Abstract: Package for electronic components is one that protects an electronic or electrical device against electrostatic discharge. Traditionally, antistatic packages are produced with polystyrene (PS) or polypropylene (PP) filled with carbon black. Recently, studies have been carried out successfully for the application of polyethylene terephthalate (PET) filled with carbon black. This work aimed to obtain and characterize nanocomposites based on PET filled with reduced graphene oxide (rGO) and compare its physicochemical properties with PET filled with carbon black and PP filled with carbon black used in anti-static packaging. PET compounds containing 0.1; 0.3; 0.5 and 0.7wt% reduced graphene oxide were obtained by the modified Hummers process from the graphite and reduced with hydrazine. The thermomechanical, electrical and morphological properties of the obtained compounds were determined. The results showed that the addition of reduced graphene oxide to PET causes an increase in the melt flow index, also increase the tensile strength and electrical conductivity. The addition of reduced graphene oxide promotes the decrease in the hardness and thermal resistance of the obtained nanocomposites. Nanocomposites based on PET containing 0.5wt% and 0.7wt% reduced graphene oxide can be used in the handling, transport and storage of electronic components since their mechanical, thermal and resistivity properties are satisfactory for this purpose.

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  • IPEN-DOC 25622

    MONTEIRO, ALEX S. ; BARREIRA, DAILI A.S. ; SILVA, JAQUELINE S. ; OLIVEIRA, RENE R. ; VALENZUELA-DIAZ, FRANCISCO R.; MOURA, ESPERIDIANA A.B. . An investigation of mechanical and thermal properties of polypropylene reinforced with different clays. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 453-463, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_45

    Abstract: Nowadays, environmental awareness and an increasing concern with the greenhouse effect have increased the interest in composite materials containing at least one of the components from natural origin. Natural clays seem to be a good alternative because they are environmentally acceptable, naturally abundant minerals, and due to their ability to intercalate and exfoliate in the polymer matrix led to an improvement in mechanical, thermal and barrier properties, compared to the neat polymer. This work presents an investigation of the effects of incorporation of two different clays on mechanical and thermal properties of polypropylene (PP) matrix. PP with 1.5–3.0 wt% of the Cloisite® (commercial clay), and light green clay (noncommercial Brazilian clay), was prepared by melt extrusion process. The neat PP and its nanocomposites were characterized by mechanical tests, SEM, DSC, TGA and XRD analyses. In addition, clay characterization by XRD has also been carried out.

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  • IPEN-DOC 25646

    SOUZA, C.D. de ; ROSTELATO, M.C.M. ; ZEITUNI, C. ; GONZALEZ, A. del C.C. ; NOGUEIRA, B.R. . New gold-198 nanoparticle synthesis to be used in cancer treatment. Medical Physics, v. 45, n. 6, p. e243-e243, 2018.

    Abstract: Purpose: Nanoparticle (NPs) is the name given to particles that are in the nanoscale (nm). Their configuration in the nanometric size promotes alteration in their physical, chemical, and biological behaviors. Gold nanoparticles have been studied for over 100 yr. Recently, gold-198 NPs are being studied for application in treat prostate cancer. The idea is to insert the radioactive NPs solution directly inside the cancer with a syringe. Although the synthesis of gold nanoparticles is extensively reported, in the majority of cases the methodology is confuse and/or not clear. Besides that, the toxicity of the reactants and stability during reactor activation must be taken into account when developing products for medical applications. We describe a new synthesis methodology for radioactive gold-198 NPs. Methods: 0.1 mM HAuCl4 containing 100 lL of 1 M NaOH was prepared in a flask equipped with a reflux condenser. The solution was brought to boil and stirred with a PTFE-coated magnetic stir-bar. Then 5 mL of Na3Ctr was rapidly added. The reaction turn from light yellow to clear, black, dark purple until the solution attained a wine-red color (2–3 min). The reaction was allowed to proceed for 7 more minutes (completing 10 in total). 1 mL of the nanoparticle solution was separated to undergo activation in IPEN’s IEA-01 reactor for activation. Results: Dynamic light scattering (DLS) confirmed 8 nm particles. The presence of gold-198 (197.968 g/mol; half-life: 2.69517; decay mode: b-; average energy: 1.3723 MeV) was confirmed by an ORTEC HPGE detector. DLS was performed after complete decay confirming the 8 nm diameter maintenance. Conclusion: We were able to achieve radioactive gold-198 NPs and are performing further studies such as: coating reactions, in-vitro and in-vivo studies. (Supporting document show a TEM image of the nanoparticles and the reaction color change described in methods.)

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  • IPEN-DOC 25645

    ALIBHAI, A.Y.; PRETTO, LUCAS R. de ; MOULT, ERIC; SCHOTTENHAMML, JULIA; OR, CHRIS; ARYA, MALVIKA; MCGOWAN, MITCHELL; BAUMAL, CAROLINE; WITKIN, ANDRE J.; DUKER, JAY S.; FUJIMOTO, JAMES G.; WAHEED, NADIA K.. Quantitative analysis of capillary non-perfusion in diabetic retinopathy using widefield OCT-angiography. Investigative Ophthalmology & Visual Science, v. 59, n. 9, 2018.

    Abstract: Purpose : Several OCT angiography (OCTA) studies suggest an association between capillary non-perfusion, a surrogate for retinal ischemia, and diabetic retinopathy (DR) severity. However, due to technical limitations, these studies focused on either 3x3mm or 6x6mm fields of view centered on the macula. In contrast, widefield fluorescein angiography (FA) studies suggest that the majority of capillary non-perfusion in early DR occurs outside of the macular region. The recent development of high-speed, widefield OCTA systems, has for the first time allowed non-invasive visualization of retinal vasculature over wider fields of view—a functionality that, in light of previous widefield FA studies, may be promising for early detection and monitoring of DR. This study aims to couple the recent technological advances in high-speed, widefield OCTA with image processing methods to allow for semi-automatic quantitative analysis of capillary non-perfusion of widefield OCTA images of diabetic eyes. Methods : A semi-automatic, texture-based algorithm that detects areas of non-perfusion on 12x12mm SS-OCTA images from the Zeiss PlexElite™ system was developed. We tested the algorithm on a series of patients with diabetes without DR (28 eyes, 21 subjects; 54.8 ± 10.9 y/o), eyes with non-proliferative DR (NPDR) (24 eyes, 16 subjects; 62.1 ± 13.2 y/o) and eyes with proliferative DR (PDR) (21 eyes, 14 subjects; 52.2 ± 12.7 y/o). Results : There was a general trend of increasing capillary non-perfusion with increasing DR severity; however, there was significant overlap between patients having different DR severities (Fig. 1). Conclusions : Quantitative analysis of widefield OCTA images may be useful for early detection and monitoring for diabetic retinopathy progression in diabetics. Additional work is needed to determine the added value of widefield OCTA.

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  • IPEN-DOC 25621

    BRIGGS, EXAMPLE; MOURA, ESPERIDIANA A.B. de ; FURUSAWA, HELIO A. ; COTRIM, MARYCEL E.B. ; OGUZIE, EMEKA E.; LUGAO, ADEMAR B. . Microplastics: a novel method for surfacewater sampling and sample extraction in Elechi Creek, Rivers State, Nigeria. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 269-281, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_27

    Abstract: The geometric increase in the production and exploitation of plastics worldwide has several advantages as well as disadvantages due to the mismanagement of plastic waste. These waste products find its way into the aquatic body. Microplastics are plastic particles with its longest diameter less than or equal to 5 mm. Their microscopic nature, irregular color and morphology have made their extraction from the buoyant organic materials problematic. This work documents for the first time, the sampling and sample extraction of microplastics in Nigeria. An optimized sampling and sample extraction protocol for surfacewaterwas developed. The extraction protocolwas developed in a laboratory study using a simulated sample that mimics the environmental sample (microplastics+organic materials). A micronized LDPE (<300 μm) was used for the study and yielded a percentage recovery rate of 82%. The digested microplastics which were subjected to SEM analysis showed a slight change in the surface morphology. Thereafter, the environmental sample was extracted using the developed laboratory protocol and a high positive result was achieved. This protocol improved NOAA’s method of extraction by excluding the use of microscope for the final extraction, which, of course, will yield a biased result. This was achieved by the addition of ethanol to the final solution.

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  • IPEN-DOC 25620

    ZAFALON, ANGELICA T. ; JUVINO, VINICIUS dos S. ; KOMATSU, LUIZ G.H. ; PARRA, DUCLERC F. ; LUGAO, ADEMAR ; SAMUEL, TEMESGEN; RANGARI, VIJAYA. Synthesis and characterization of PVP/CaCO3-Ag blend hydrogel by gamma irradiation: study of drug delivery system and antimicrobial activity. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 255-265, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_26

    Abstract: Chronic wounds are skin injuries with failed healing. They have become a public health problem that affects more than 2% of the population and the presence of bacteria resistances difficult of treatment. Pseudomonas aeruginosa is opportunist pathogens and the treatment is difficult and requires a long period of treatment. Hydrogels are structure polymeric tridimensional and biocompatible. They have been used as a controlled delivery system for treatment of topic infection. Studies have reported calcium carbonate and silver ion can improve the mechanical properties and biocide activity of hydrogel. Here in this study, hydrogels loaded CaCO3-Ag were prepared using poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar, calcium carbonate, silver nitrate followed gamma irradiation with 25 kGy dose. The gel fraction, behavior swelling and biocide action against P. aeruginosawas investigated. The degree of swelling of the hydrogel loaded CaCO3-Ag was 12% higher than the unloaded and exhibited antibacterial effects against P. aeruginosa and biofilm.

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  • IPEN-DOC 25619

    MARCHINI, LEONARDO G. ; PARRA, DUCLERC F. ; RANGARI, VIJAYA K.. Incorporation of silver nanoparticles in zinc oxide matrix in Polyester Thermoplastic Elastomer (TPE-E) aiming antibacterial activity. In: LI, BOWEN (Ed.); LI, JIAN (Ed.); IKHMAYIES, SHADIA (Ed.); ZHANG, MINGMING (Ed.); KALAY, YUNUS E. (Ed.); CARPENTER, JOHN S. (Ed.); HWANG, JIANN-YANG (Ed.); MONTEIRO, SERGIO N. (Ed.); BAI, CHENGUANG (Ed.); ESCOBEDO-DIAZ, JUAN P. (Ed.); SPENA, PASQUALE R. (Ed.); GOSWAMI, RAMASIS (Ed.). Characterization of Minerals, Metals, and Materials. Cham, CZ, Switzerland: Springer Nature Switzerland AG, 2019. p. 79-88, (The Minerals, Metals & Materials Series). DOI: 10.1007/978-3-030-05749-7_9

    Abstract: The purpose of present study is to evaluate the antimicrobial potential of Thermoplastic Polyester Elastomer (TPE-E) incorporated with zinc oxide added with colloidal dispersion of metallic silver adsorbed on pyrogenic silica (AgNPs_ZnO). A combination of single screw extruder and hot press technique was used to fabricate these polymer nanocomposite films. These polymer nanocomposite films were prepared by mechanical mixing of 1% (w/w) of oil, anti-oxidant 0.05% (w/w), TPE-E granules 0.5% (w/w) and followed by single screw extruder to produce the pellets. As-prepared pellets were further melted for films in hot press technique. Antimicrobial activity was evaluated according to Japan Industrial Standard—JIS Z 2801 in TPE-E compounds against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). TPE-E samples containing additives 0.05 and 0.5% AgNPs_ZnO presented 75 and93%bactericidal reduction for Gram-negative bacteria Escherichia coli (E. coli) and 76 and 92% bactericidal activity reduction for Gram-positive bacteria Staphylococcus aureus (S. aureus), respectively.

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  • IPEN-DOC 25618

    AVILLA, LEONARDO S.; MACHADO, HELENA; ARAUJO-JUNIOR, HERMINIO I. de; MOTHE, DIMILA; ROTTI, ALLINE; OLIVEIRA, KAROLINY de; MALDONADO, VICTORIA; FIGUEIREDO, ANA M.G. ; KINOSHITA, ANGELA; BAFFA, OSWALDO. Pleistocene EQUUS (Equidae: Mammalia) from Northern Brazil: evidence of scavenger behavior by ursids on south american horses. Ameghiniana, v. 55, n. 5, p. 517-530, 2018. DOI: 10.5710/AMGH.05.07.2018.3069

    Abstract: During paleontological surveys conducted in 2013 and 2014 in Quaternary deposits from the Gruta do Urso cave, Tocantins State, nine isolated teeth and five postcranial elements of Equus neogeus were recovered. Absolute datings indicate that E. neogeus inhabited the surroundings of Gruta do Urso cave during the Last Glacial Maximum. The specimens probably represent very young individuals that died outside the cave, were weathered prior to the final burial, with ontogenetic and taphonomic similarities. Herein, we report the first scavenger interaction of ursids and equids in the South American fossil record.

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  • IPEN-DOC 25617

    SILVA, J.; ELIAS, M.; LIMA, N. ; CANEVAROLO, S.. Morphology in multilayer blown films of polypropylene and ethylene-octene copolymer blends. International Polymer Processing, v. 33, n. 3, p. 345-354, 2018. DOI: 10.3139/217.3526

    Abstract: In this work the microstructure of multilayer blown films consisting of a core layer placed between two external ones is studied. The core layer is a blend with 70% (w/w) of a homopolypropylene PP and 30% of a metallocene-catalyzed ethylene- octene copolymer mEOC (LLDPE or VLDPE), whereas the external symmetrical layers are composed of LLDPE or they have the same composition as the core layer. The PP and PE crystalline phases formed during the film blowing were investigated by thermal analysis, mechanical properties, TEM morphology and X-ray diffraction pole figures. These films successfully combine the high mechanical strength of PP with the quasi-isotropic behavior of blown PE. Multilayer film containing PP/mEOC blends, particularly blends of PP70/LLDPE30, show better balanced tensile properties when compared at crossed directions. The presence of VLDPE in the blends shifts downwards the melting and crystallization temperatures and crystallinity of PP. X-Ray pole figures suggest the occurrence of epitaxial crystallization of the PE phase upon the PP crystals in these PP/mEOC blend films.

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  • IPEN-DOC 25616

    CAMPOS, FABIO E. de . Estudo, desenvolvimento e construção de célula multipropósito para produção de radiofármacos, em acordo com parâmetros e padrões de Boas Práticas de Fabricação (BPF) / Study, development and assembling of a multipurpose hot cell for radiopharmaceuticals production in accordance with the Good Manufacturing Practices (GMP) requirements . 2018. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 667 p. Orientador: Wilson Aparecido Parejo Calvo. Coorientador: Elaine Bortoleti de Araújo.

    Observação: Acesso restrito até 08/02/2021

    Abstract: Em cumprimento aos requisitos normativos e regulatórios, considerados os padrões nacionais e internacionais de Boas Práticas de Fabricação (BPF) de medicamentos, o ambiente de produção de radiofármacos (célula) é determinante para a qualidade do medicamento, quanto aos limites estabelecidos na legislação vigente para níveis de contaminantes, discriminados como partículas não viáveis (partículas em geral) e microrganismos viáveis, corroborado, ainda, pelo fator de decaimento radioativo, uma vez que os radiofármacos devem ser liberados e administrados aos pacientes pouco tempo após sua produção. Tão importante quanto proteger o produto contra uma possível contaminação do meio ambiente é o operador estar protegido contra a contaminação pelo manuseio do produto. Assim, o estudo, concepção e desenvolvimento de uma célula nacional implicou em análises minuciosas de cada um dos elementos de composição do ambiente de produção e de sua operação, orientado pelo conceito de Quality by Design, metodologia que vem sendo aplicada, recentemente, na indústria farmacêutica. O conhecimento do produto, a configuração do espaço de operação por meio de mockup, a abordagem quanto aos atributos críticos da qualidade, com definições claras quanto aos parâmetros do processo produtivo, validados em experimentos, definiram uma célula multipropósito para produção de radiofármacos em acordo com BPF.

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  • IPEN-DOC 25615

    ZAFALON, ANGELICA T. . Synthesis and characterization of hydrogels loaded neomycin for infection topic treatment and veterinary use / Síntese e caracterização de hidrogéis com neomicina para tratamento de infecções tópicas e uso veterinário . 2018. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 95 p. Orientador: Duclerc Fernandes Parra.

    Observação: Acesso restrito até 25/10/2020

    Abstract: Hydrogels are natural or synthetic polymer systems that have been vastly applied in the pharmaceutical industry due to their high soft tissue biocompatibility. These hydrogels have been used in dressings as a controlled drug release system. In this study, hydrogels were prepared using poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG), agar and neomycin followed by gamma irradiation to promote crosslinking and sterilization. The influence of the irradiation process at 25 kGy dose was investigated. The gel fraction and maximum swelling were estimated using physicochemical methods and found about 95% gel fraction and 1100% swelling after 8 hours of immersion. Neomycin released from the hydrogel was measured by the Liquid Chromatography-Mass Spectrometry method and the drug concentration remained constant for 48 hours. Hydrogel / neomycin exhibited antibacterial effect against bacteria and biofilm of Pseudomonas aeruginosa and Staphylococcus aureus. The hydrogel was used in the treatment of pododermatitis in penguins healing process without signs of contamination. With these results, it can be inferred that the hydrogel / neomycin is a suitable candidate for wound dressings.

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  • IPEN-DOC 24810

    SOUZA, CARLA D. de . Parâmetros para produção de fontes de iodo-125 utilizadas em Braquiterapia / Parameters for the production of iodine-125 sources used for brachytherapy . 2016. Tese (Doutorado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 75 p. Orientador: Maria Elisa Chuery Martins Rostelato.

    Observação: Acesso restrito até 09/01/2021

    Abstract: Como o diagnóstico do cancer de próstata está cada vez mais eficiente e cânceres em pacientes cada vez mais jovens estão sendo descobertos, a necessidade de desenvolvimento de tratamentos que provoquem menores efeitos colaterais é muito grande. Além disso, tratamentos rápidos, com pouca dor e eficientes são de extremo interesse também para os pacientes com idade avançada. Com a finalidade de diminuir custos e disponibilizar o tratamento para mais homens, o IPEN está construindo um laboratório para a fabricação de fontes radioativas para o tratamento braquiterápico. Essas fontes são inseridas diretamente dentro do câncer e utilizam a radiação do iodo-125 para destruir o tumor. Como a reprodução de técnicas existentes seriam custosas, novos métodos para fixação do Iodo-125 no núcleo de prata dessa semente devem ser desenvolvidas. Este trabalho apresenta dois métodos inéditos. O primeiro, desenvolvido em parceria com o Instituto de Química da USP, utilizou a solução piranha para decapar a superfície e o nitrato de ferro III para remover um elétron da prata metálica. O iodo-125 adere na superfíce com 37,76% de eficiência. No segundo métodos três variações foram apresentadas inspiradas em conceitos utilizados por joalheiros: núcleos de prata escurecidos pelo talco comum, núcleos escurecidos com prata e tiossulfato de sódio e núcleos escurecidos somente com tiossulfato de sódio. Os resultados foram 19,17%, 53,39% e 71,70% de eficiência, respectivamente. Outros aspectos da reação foram discutidos: pH da reação, frasco utilizado no experimento, presença de luz, técnicas de medição, volume da reação, segurança e pureza química. As modificações na superfície foram visualizadas por MEV e analizadas por EDX. Como resultado, uma nova metodologia para produção de sementes de iodo-125 foi desenvolvida e analisada.

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  • IPEN-DOC 24809

    ANTONIO, PATRICIA L. ; OLIVEIRA, RAQUEL A.P.; KHOURY, HELEN J.; CALDAS, LINDA V.E. . Evaluation of the thermally and optically stimulated response of an Italian Obsidian irradiated in 60Co beams. Radiation Physics and Chemistry, v. 155, SI, p. 115-120, 2019. DOI: 10.1016/j.radphyschem.2018.06.034

    Abstract: From Obsidian silicate, in its natural form, pellets were manufactured adding Teflon to the material in powder. These pellets were exposed to the gamma radiation beams of a 60Co source in a dose interval from 10 Gy to 10 kGy. The Obsidian in powder was investigated in relation to its physical and chemical characteristics, by means of the X-ray diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy techniques. After the irradiation procedure, the signal of the samples was evaluated by means of three techniques: thermoluminescence (TL), optically stimulated luminescence (OSL) and thermally stimulated exoelectron emission (TSEE). The objective of this work was to verify the TL, OSL and TSEE response of the Obsidian+Teflon pellets after exposure to high doses of gamma radiation. Different response characterization tests were performed, as TL and TSEE emission curves, OSL signal decay, reproducibility, dose-response curves, lower detection limits and fading. From these results, it can be observed that the Obsidian+Teflon pellets present good conditions to be used as high dose gamma radiation detectors; the results obtained with the OSL technique were the most adequate in terms of response in function of absorbed dose. The fading of the signals, varying from about 26% (TSEE) to 44% (OSL), in a time interval of 360 h post-irradiation, also showed favorable results for the use of this material as radiation detector, when the measurements are taken after a defined time interval.

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  • IPEN-DOC 24801

    NASCIMENTO, ERIBERTO O. do; OLIVEIRA, LUCAS N. de ; CALDAS, LINDA V.E. . Improvement of Sievert Integration Model in brachytherapy via inverse problems and Artificial Neural Networks. Radiation Physics and Chemistry, v. 155, SI, p. 260-264, 2019. DOI: 10.1016/j.radphyschem.2018.05.024

    Abstract: Increasing the radial distance, the accuracy of the Sievert Integration Model (SIM) decreases in a nonlinear manner, adding errors up of 10% into the dose rate calculations; a similar fact occurs to the 2D anisotropy function where the errors may achieve 30% as already was related. For that reason, this paper sought an innovative approach to optimize the error variance and its biases of dose rate calculations around a Nucletron brachytherapy source of 192Ir from 0 to 10 cm taken in the radial distance, using an improved SIM through a hybrid coupling of Artificial Neural Networks (ANNs) and Inverse Problem Theory (IPT). Since the traditional approach relies into the use of a small data set of dose rate, the ANNs generalized these doses, making possible to search more broadly optimum parameters to SIM using the IPT. The results showed excellent accuracy evaluated with the Root Mean Square Percentage Error (RMSPE). In conclusion, the low RMSPE values indicate that the methodology is consistent, showing an excellent agreement with the state of art of dosimetric measurement techniques.

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  • IPEN-DOC 24788

    PERINI, ANA P. ; SANTOS, WILLIAM S.; NEVES, LUCIO P.; BELINATO, WALMIR; CALDAS, LINDA V.E. . Estimation of conversion coefficients for absorbed and effective doses for pediatric CT examinations in two different PET/CT scanners. Radiation Physics and Chemistry, v. 155, SI, p. 9-16, 2019. DOI: 10.1016/j.radphyschem.2018.07.009

    Abstract: Normally, during medical procedures, special attention must be given to pediatric patients when compared to adults. This is specially relevant during procedures involving ionizing radiation, as CT scans, given that children are considerably more sensitive to radiation induced stochastic effects than adults. In order to investigate the radiation doses on radiosensitive organs of pediatric patients, undergoing head, chest and abdomen CT procedures, numerical dosimetry was employed in this work. The novelty is the use of a new set of pediatric virtual anthropomorphic phantoms, coupled with Monte Carlo simulation, to determine the conversion coefficients for absorbed and effective doses. Two CT equipment were simulated, taking into account the main characteristics of those commercially available. The results were converted to conversion coefficients (mGy/100 mA) for several organs and tissues, and the highest values were obtained for the newborn phantom. This numerical approach employed a new and reliable technique for pediatric CT dosimetry.

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  • IPEN-DOC 24780

    ROCHA, F.D.G. ; VILLANI, D. ; CAMPOS, V.P. ; NOGUEIRA, M.S.; GOULART, M.E.; SICHITO, V.A.; CAMPOS, L.L. . Performance of TL and OSL techniques using CaSO4 and Al2O3 dosimeters for mean glandular dose (MGD) and entrance surface skin dose (ESD) determination in a digital mammographic unit as alternative dosimeters. Radiation Physics and Chemistry, v. 155, SI, p. 48-52, 2019. DOI: 10.1016/j.radphyschem.2018.06.037

    Abstract: The mammography is the most important and simple tool in the diagnosis of breast diseases in women. In digital mammography, the process of image acquisition, display and storage are separated which allows optimization of each. Despite the innumerous advantages of this technique, such as an accurate diagnosis for women with dense breast, it was noticed an increase of radiation doses to obtain the images by this system. As with any examination that includes x-rays, there is always a small stochastic risk of inducing cancer, it is therefore important to evaluate the risk from the dose delivered to the patient during the screening process. The mean glandular dose within the breast is the recommended quantity to evaluate the risk from radiation to the breast. To guarantee proper conditions of protection for patients, the radiation dose should be as low as reasonably achievable possible and simultaneously compatible with image quality requirements. Thus, this work proposes the use of the thermoluminescent (TL) CaSO4:Dy sintered discs, produced at IPEN, widely used in individual, environmental and area monitoring in Brazil, and Al2O3:C optically stimulated luminescence (OSL) ‘dot’ dosimeters, manufactured by Landauer® Inc., as application as easy-to-use and low cost alternative dosimeters to evaluate the entrance skin doses (ESD) delivered to patients, the half value layer (HVL) and the mean glandular doses (MGD) in a mammographic digital unit, comparing these two techniques with the results obtained using an Allin- one QC meter. The results obtained demonstrated that the TL and OSL dosimetry systems and the CaSO4 and Al2O3 dosimeters used are able to evaluate the entrance skin dose as well as mean glandular doses in a digital mammographic unit accurately within the requirements, and they can be considered a practical, simple, easy-touse and low cost tools for verification of these items in a Quality Assurance Program.

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  • IPEN-DOC 24752

    SOARES, MARIA R. ; SANTOS, WILLIAM S.; NEVES, LUCIO P.; PERINI, ANA P. ; BATISTA, WILSON O.G.; BELINATO, WALMIR; MAIA, ANA F.; CALDAS, LINDA V.E. . Dose estimate for cone beam CT equipment protocols using Monte Carlo simulation in computational adult anthropomorphic phantoms. Radiation Physics and Chemistry, v. 155, SI, p. 252-259, 2019. DOI: 10.1016/j.radphyschem.2018.06.038

    Abstract: Cone beam computed tomography (CBCT) has become essential for dental diagnoses in the last decade. This is supported by its low cost and low doses, when compared to medical CT. Following this increase in CBCT procedures, it is necessary to ensure the image quality within low radiation doses to the patients. This is an especially difficult challenge in CBCT, given the number of equipment models (more than 50), radiographic techniques that may be employed, and technical information not available to the users by the manufacturers. The objective of this study was to estimate the cancer risk, effective and absorbed doses in tissues and organs for CBCT protocols intended for dental use. Monte Carlo (MC) simulations were used to estimate these quantities in tissues and organs with radiological importance, as those suggested by the International Commission of Radiological Protection (ICPR) report ICRP 103. Five different fields of view (FOV) were simulated to i-Cat Classic CBCT, using the MCNPX code. The virtual anthropomorphic phantoms FASH3 (Female Adult MeSH) and MASH3 (Male Adult MeSH) were also used. The effective dose estimative was in the range 75.15–142.20 μSv. The largest contribution to the effective dose was from the salivary glands (17%), thyroid (27%) and remainder tissues (28%). The results of this work showed that the effective and absorbed doses in tissues/organs vary according to the FOV, exposure parameters, and the positioning of the beam, relative to the radiosensitive organs. Furthermore, for the same exposure conditions, women can exceed the total risk of cancer by 26–34%, when compared to men.

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  • IPEN-DOC 24708

    BARRERA, G.R.; SOUZA, L.F.; NOVAIS, A.L.F.; CALDAS, L.V.E. ; ABREU, C.M.; MACHADO, R.; SUSSUCHI, E.M.; SOUZA, D.N.. Thermoluminescence and optically stimulated luminescence of PbO–H3BO3 and PbO–H3BO3–Al2O3 glasses. Radiation Physics and Chemistry, v. 155, SI, p. 150-157, 2019. DOI: 10.1016/j.radphyschem.2018.02.005

    Abstract: In the present work some dosimetric and structural properties of the lead borate glass (4.5PbO-1.9H3BO3) and lead aluminum borate glass (11.1PbO-2.9H3BO3-0.2Al2O3) were investigated. The glass samples were produced by fusion and fast cooling method. The dosimetric characterization was performed via thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. For this characterization, the samples were irradiated with a beta source (90Sr/90Y). TL emission curves, kinetic parameters, OSL decay curves, dose response curves, and the correlation between TL and OSL results were obtained. X-ray diffractometry (XRD) and infrared spectroscopy (FT-IR) of the samples were also performed. The XRD analyses confirmed the amorphous nature of the investigated glasses and the FT-IR analyses showed the different borate groups in their compositions. The TL emission curves of the glasses are composed by three peaks, located at different temperatures. The dose response curve in both TL and OSL analyses indicated linearity for most of the dose range studied. The OSL decay curves exhibited two components with different decay times.

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  • IPEN-DOC 25613

    CASTRO, PEDRO A.A. de ; ZEZELL, DENISE M. ; MORAIS, MYCHEL R.P.T.; ZORN, TELMA M.T.. ATR-FTIR spectral monitoring of burn wound healing in skin by hierarchical cluster. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: Efficient biochemical characterization of burn wound healing stages can improve clinical routine to adjust the patient treatment. The Fourier Transform Infrared spectroscopy coupled with Attenuated Total Reflectance (ATR-FTIR) is an analytical technique that has potential capability to provide spectral biomarkers in biological material. This study aims to evaluate the feasibility of using ATR-FTIR to classify burned skin, to be able, in the future, to follow the regenerative process in patients. Wistar rat burn tissues were evaluated by ATRFTIR spectroscopy at 3, 7, 14, 21 days after burn and compared with the healthy group samples (H). For the acquisition of one spectrum, 150 scans were averaged with a resolution of 4 cm-1 and wavenumbers ranging from 4000 to 400 cm-1. Analysis of the spectra was performed using MatLab R2017a (MathWorks, EUA) software. The fingerprint region between 900 to 1800 cm-1 was separated and normalized by amide I band area. For smoothing purpose, spectra were submitted to Savitzky-Golay filter with a polynomial of second order in a fifteen points window. All spectra data were submitted to the hierarchical cluster using the single method and standardized Euclidean distance. The classification results demonstrated separation to non-wounded groups with an accuracy of 91,8% (H vs. 3D), 87,83% (H vs. 7D) and 97,96% (H vs. 14D). Interestingly, when the results from the healthy group were compared to the 21D group, the accuracy dissimilarity was 26%, which suggests that they are chemically similar implying that after 21 days the burned lesions are entirely recovered. These findings indicate that when an adequate multivariate method is applied, ATR-FTIR is suitable to detect the wounded and non-wounded skin as well as its healing stages. In this way, it is possible to conclude that ATR-FTIR can be an auxiliary analysis for the clinical routine for skin burn wound healing.

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  • IPEN-DOC 25612

    TEIXEIRA, LUCIA R.C. ; CARVALHO, MARIANA T.; GOMES, ANDERSON S.L.; ZEZELL, DENISE M. ; AMARAL, MARCELLO M.. Evaluation of vascular lesions on cutaneous and mucosa tissue in head and neck regions by Doppler Optical Coherence Tomography. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: Vascular lesions are one of the most common congenital and neonatal abnormalities, 60% of the cases affect the head and neck region. In most cases these lesions involute spontaneously with no consequences for the patient health, although complications caused by tissue deformities occur in 10%. The proper diagnosis of the different lesions type has impact on the proper choice of patient treatment. The Optical Coherence Tomography (OCT) technique obtains non-invasive real-time cross-section images of tissue structures with high resolution (ª 5μm), about 20 times greater than ultrasound. One of the characteristics of vascular lesions are the presence of blood vessels on the superficial layer of the skin, not present on normal tissue. Using the so-called Doppler OCT it is possible to identify the presence of blood flow and vessels on OCT images. The aim of this work was to evaluate the differences in the architecture of blood vessels in different types of lesions on cutaneous and mucosa tissue in head and neck regions by Optical Coherence Tomography and Doppler Optical Coherence Tomography. After approved by the Ethics Committee of IMIP (protocol no. 728.993), 27 patient lesions were imaged using a Doppler-OCT system (OCS1300SS; Thorlabs GmBH), at 1325 nm of central wavelength and 100 nm of bandwidth. Using the ImageJ software, the average diameter and mean depth of the blood vessels were measured. The average diameter and mean depth of the blood vessels were respectively equal to 114μm ± 92μm and 304.3μm ± 99μm on vascular malformation, 38.6μm ± 19μm and 297.8μm ± 132μm on skin hemangiomas, 45μm ± 16μm and 520.5μm ± 189.5μm on oral mucosa hemangioma (lips), 157.5μm ± 90μm and 695μm ± 136μm on lip lymphatic malformation, and 128μm ± 63μm and 689μm ± 217μm on lip vascular malformation. Using the flow information provided by Doppler OCT, it was possible to evaluate the differences on each lesion type. It was possible to obtain a diagnosis method to differentiate each vascular lesion on skin and oral mucosa, providing information for the early stage treatment of the lesions which will evolute.

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  • IPEN-DOC 25611

    DIAS, DERLY A. ; PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; SUGAHARA, VANESSA M.L. ; ZAMATARO, CLAUDIA B. ; ZEZELL, DENISE M. ; MATHOR, MONICA B. . Effects of gamma irradiation on bovine bone microhardness and molecular structure. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: The skeletal systems is a complex mixed compounds, organic and inorganic, that should present a mechanical resistance to perform functions as protection of the vital organs and load distribution. Gamma radiation is an ionizing radiation that comes from radioative sources or X-ray generator and it is commonly used in health establishments such as radio diagnostic exams, radiotherapy and sterilization of allograft. The characterization of the irradiated bone tissue can be an important tool in the study of the components that are aÆected and how much each dose of ionizing radiation can alter its mechanical properties. This information will be very important in in vitro and ex vivo studies where sterilization of the bone material is necessary and may still be useful in understanding the eÆects on the bone tissue of patients undergoing short-term radiotherapy. For this, 110 samples of bovine femur diaphysis were randomized into 11 groups: G1- untreated (control); G2 to G11 were submitted to gamma irradiation (60Co Gammacel). Samples were polished before irradiation and submitted to a Knoop Microhardness Test to determine the hardness of bovine bone and Fourier transform Infrared spectroscopy (FTIR). Spectra were collected in the midinfrared range in Attenuated Total Reflectance (ATR) sampling mode associated whit PCA multivariate technique to evaluate the molecular changes in bone matrix. The microhardness analysis did not present a significant statistical diÆerence between the irradiated and control groups, showing that ionizing radiation did not aÆect the mechanical structure of the samples, on a micro scale. The results of FTIR with the PCA technique were eÆective in separating all groups, especially those irradiated with doses of 0.002 kGy, 10 kGy and 35 kGy. We conclude that ATR-FTIR spectroscopy associated with PCA is a good method to evaluate the biochemical changes promoted by ionizing radiation in bone matrix. It was observed that hardness was not altered by gamma irradiation and FTIR spectroscopy associated with PCA is a good method to analyze the changes in bone tissue submitted to ionizing radiation.

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  • IPEN-DOC 25610

    PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; ZEZELL, DENISE M. ; DEL VALLE, MATHEUS; ANA, PATRICIA A.. Optical coherence tomography provides the optical attenuation coefficient of bovine dentin irradiated by Nd:YAG. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: Optical Coherence Tomography (OCT) is a non-destructive and non-invasive technique which provides transverse images of biological structures contactless with the sample, with no use of ionizing radiation to penetrate in the sample under analysis. These characteristics allow its clinical use without any side eÆects to the patient. The optical attenuation coe±cient (OAC) is obtained by OCT and is related to the characteristics of the tissues. This study aims to analyze the OAC from the OCT signal in bovine dentin to distinguish sound from demineralized dentin. For this, sixty 8mm2 blocks of bovine root dentin, were randomized into 4 groups: G1- untreated; G2- treated with acidulated phosphate fluoride (APF, [F]=1.23%, pH=3.3 to 3.9); G3- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz- Lares Research R∞) without photoabsorber; G4- irradiated with Nd:YAG laser (1064 nm, 0.6W, 10 Hz- Lares Research R∞) using a coal paste as photoabsorber. All samples were submitted to a 3-day erosive demineralization protocol (Citric acid 1%, pH=3.6, 5 min, 2x/day) under agitation, and remineralization (artificial saliva, pH=7, 120 min) cycling. In this study, it was noticed that the values of optical attenuation coe±cient of all samples decreased after the erosive cycling. This finding indicates that the demineralization promoted by acids, such as the citric acid creates empty spaces in the structure of dentin that increases the number of interfaces and, as a consequence, increases the scattering of light and decreases the values of optical attenuation coe±cients. It is possible to conclude that the optical attenuation coe±cient, calculated from the OCT signal, is able to distinguish sound from demineralized bovine dentin. This quantitative parameter can be used for diagnosis and to monitor the evolution of mineral loss in patients in near future.

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  • IPEN-DOC 25609

    ZAMATARO, CLAUDIA B. ; PEREIRA, DAISA L. ; GOMES, GABRIELA V. ; ALVES, NATHALIA Z. ; CASTRO, PEDRO A.A. ; DIAS, DERLY A. ; ZEZELL, DENISE M. ; SCAPIN, MARCOS A. . Molecular characterization of ex-vivo natural bovine dental enamel. In: ENCONTRO DE OUTONO, 41., 06-11 de maio, 2018, Foz do Iguaçu, PR. Resumo... São Paulo: Sociedade Brasileira de Física, 2018. p. 1-1.

    Abstract: Bovine teeth are widely used to infer results on a human population. Considering this, an analysis of the mineral content of bovine enamel, focusing the hidroxiapatite (HA), was carried out to evaluate the homogeneity of the sample universe for future experiments with laser irradiation as a substitute of human teeth enamel. Twelve samples of 5 x 5 mm bovine enamel were prepared and polished plane. The mineral content was calculated through surface microhardness (SMH) and morphology by scanning electron microscopy (SEM). Main molecular components of the enamel were analysed by Energy Dispersive X-ray Spectroscopy (EDS). Surface microhardness is an indirect indicator of the mineral content of the samples, which was 258.2 (38.8) KHN. The compounds present in the samples, the values of Calcium and Phosphate oxides and the ration Ca/P were analizes. As expected Phosphorus pentoxide and Calcium oxide were the main constituent of the samples (57.4 to 59.9%). The CaO/P2O5 ratio shows a variation with linear correlation (R2 = 1). The elemental ratio (Ca/P) shows a change in the elemental content with linear correlation (R2 = 1). 30% of the samples presented Strontium oxide, 30% had Zirconium dioxide, 10% had Magnesium oxide and 40% had Silicon dioxide. All samples showed Sulfur trioxide, Iron trioxide and Chlorine. 10% did not shown Zinc oxide. 5% had Potassium oxide and Nickel oxide in its composition. The surface microhardness results, although only for the initial homogenization of the sample universe, showed a Knoop hardness number within a spectrum similar to that of natural hydroxyapatite of human origin. The EDS results show that bovine enamel hydroxyapatite present great similarity with that from human enamel hydroxyapatite from the point of view of chemical composition. These results corroborate the use of bovine hydroxyapatite in substitution of hydroxyapatite of human origin. Despite the inter-species similarity, it is possible to note that in the same species the composition of hydroxyapatite varies. In the bovine species, the feeding, the period of formation of the dental germs and the origin are more standardized and controlled than in humans. Nevertheless, it is possible to notice a variation of the components elements of bovine dental enamel, and it is necessary to restrict an interval of hardness and Ca/P values to homogenise the samples properties for use in any experiment.

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  • IPEN-DOC 25608

    LIMA, CASSIO ; CORREA, LUCIANA; BYRNE, HUGH J.; ZEZELL, DENISE . FTIR microspectroscopy discriminating skin cancer using tissue sections on glass. In: CONFERENCE SPEC, 10th, June 10-15, 2018, Glasgow, UK. Resumo expandido... Manchester, UK: The International Society for Clinical Spectroscopy, 2018. p. 113-114.

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  • IPEN-DOC 25607

    CASTRO, PEDRO ; ZORN, TELMA; ZEZELL, DENISE . Biochemical characterization of skin burn wound healing using ATR-FTIR. In: SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, October 08-10, 2018, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2018. DOI: 10.1109/SBFoton-IOPC.2018.8610943

    Abstract: Efficient biochemical characterization of skin burn healing stages can improve clinical routine to adjust patients treatment. The golden standard for diagnosing skin burning stages is the histological biopsy. This practice is often expensive and technically challenging. There have been advances in the treatment, and diagnostic of the critical skin burned patients due to the increase of multidisciplinary collaboration. The contributions from different fields of biomedical engineering motivate to develop a better procedure for clinical applications. Considering the difficulty of monitoring wound healing the Fourier Transform Infrared coupled with an Attenuated Total Reflectance (ATR-FTIR) accessory is an analytical technique that can provide information regarding spectral biomarkers in biological materials. This study aimed to evaluate the classification feasibility provided by ATR-FTIR technique in the burned skin to follow the regenerative process in vivo. 40 skin burned samples from the Wistar rats dorsum at 3,7, 14, 21 days after burn were compared with the corresponded healthy group samples, by registering their infrared absorption spectra in FTIR Thermo Nicolet 6700 coupled to a diamond crystal ATR. The spectra were separated in the region 900 to 1800 cm-1 for further chemometric calculations. The second derivative of spectra was applied for discrimination, which results demonstrated differences from control and burns wounded groups, as well as among, burn wounded groups, using Amide I (1628 cm-1) and Amide II (1514 cm-1) bands. Amide I and Amide II bands are two significant bands of the infrared protein spectrum. The Amide I band is mainly associated with the C=O stretching vibration (70-80%) and is directly related to the backbone conformation. The Amide II band results from the N-H bending vibration (40-60%) and from the C-N stretching vibration (18-40%). This band is conformationally sensitive. These bands suggest proteins activity changing associate to inflammatory and maturation stages when it is compared with the healthy group. The statistical difference with amide I occur in proliferation and maturation stages. These findings indicate that ATR-FTIR is suitable to detect the burn wound healing stages and in the future can be an auxiliary instrument for clinical routine.

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  • IPEN-DOC 25606

    LIMA, CASSIO ; CORREA, LUCIANA; BYRNE, HUGH; ZEZELL, DENISE . K-means and Hierarchical Cluster Analysis as segmentation algorithms of FTIR hyperspectral images collected from cutaneous tissue. In: SBFOTON INTERNATIONAL OPTICS AND PHOTONICS CONFERENCE, October 08-10, 2018, Campinas, SP. Proceedings... Piscataway, NJ, USA: IEEE, 2018. DOI: 10.1109/SBFoton-IOPC.2018.8610920

    Abstract: Fourier Transform Infrared (FTIR) spectroscopy is a rapid and label-free analytical technique whose potential as a diagnostic tool has been well demonstrated. The combination of spectroscopy and microscopy technologies enable wide-field scanning of a sample, providing a hyperspectral image with tens of thousands of spectra in a few minutes. In order to increase the information content of FTIR images, different clustering algorithms have been proposed as segmentation methods. However, systematic comparative tests of these techniques are still missing. Thus, the present paper aims to compare the ability of K-means Cluster Analysis (KMCA) and Hierarchical Cluster Analysis (HCA) as clustering algorithms to reconstruct FTIR hyperspectral images. Spectra for cluster analysis were acquired from healthy cutaneous tissue and the pseudo-color reconstructed images were compared to standard histopathology in order to assess the number of clusters required by both methods to correctly identify the morphological skin components (stratum corneum, epithelium, dermis and hypodermis).

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  • IPEN-DOC 25605

    CASTRO, PEDRO ; LIMA, CASSIO ; ZORN, TELMA M.T.; ZEZELL, DENISE M. . FTIR spectroscopy: an optical method to study wound healing process. In: LATIN AMERICA OPTICS AND PHOTONICS CONFERENCE, November 12-15, 2018, Lima, Peru. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: In this study, we investigated the ability of Fourier transform infrared spectroscopy to discriminate healthy tissue and thermal injury, aiming the development of an optical method to evaluate the wound healing process.

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  • IPEN-DOC 25604

    LIMA, CASSIO A. ; CORREA, LUCIANA; BYRNE, HUGH J.; ZEZELL, DENISE M. . Diagnosis of advanced skin cancer using Infrared spectral histopathology. In: LATIN AMERICA OPTICS AND PHOTONICS CONFERENCE, November 12-15, 2018, Lima, Peru. Resumo expandido... Washington, DC, USA: OSA, 2018.

    Abstract: In this study, we investigated the feasibility of Infrared Spectral Histopathology to diagnose invasive squamous cell carcinoma using hematoxylin and eosin stained tissue placed on conventional glass slides, as used in the pathologist workflow.

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

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

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

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

Exemplo:

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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

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

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

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

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

ATENÇÃO!

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

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

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

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


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