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Sample records for combustivel empregando espectrometria

  1. Determinação indireta de N-total em plantas por espectrometria de absorção atômica com chama empregando uma mini-coluna de AgCl(s

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    Carneiro Josiane Meire Tolotti

    2001-01-01

    Full Text Available Um sistema de análises químicas por injeção em fluxo empregando uma mini-coluna de AgCl(s é proposto para a determinação de nitrogênio total em plantas por espectrometria de absorção atômica com chama. O método se baseia na remoção de íons Ag+ por amônia com formação do complexo diamino argentato(I e posterior direcionamento da amostra a um espectrômetro de absorção atômica onde prata é monitorada. Nitrogênio foi determinado em sete amostras de referência (três replicatas com precisão e exatidão comparáveis às do procedimento condutimétrico. O sistema é estável, apresentando apenas pequenas variações em sensibilidade (< 2 % durante períodos de operação de 4 horas. A velocidade analítica é de aproximadamente 100 h-1 e a repetibilidade das medidas é satisfatória (desvio padrão relativo em geral < 0,02.

  2. Identificação de compostos voláteis da cúrcuma empregando microextração por fase sólida e cromatografia gasosa acoplada à espectrometria de massas Identification of volatile compounds of turmeric using solid phase microextraction and gas chromatography coupled to mass spectrometry

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    Adriana R. Mata

    2004-03-01

    Full Text Available Compostos voláteis da cúrcuma (Curcuma longa L. cultivada no Brasil foram isolados por microextração por fase sólida. Os rizomas foram cozidos em solução de bicarbonato de sódio 0,1%, fatiados, secos e triturados. Visando estabelecer o sistema ideal para a microextração, fibras de polidimetilsiloxano de 100µm de espessura foram expostas ao headspace de frascos de 10mL. Estudou-se a influência das seguintes variáveis sobre o rendimento dos compostos voláteis obtidos: amostras em pó (0,1 a 1,0g e em solução (40mg/L, diferentes temperaturas (40 a 70ºC e tempos (2 a 20min de partição. O efeito da temperatura (210 a 240ºC e do tempo (3 e 5min de dessorção também foi avaliado. As melhores condições para a partição dos compostos voláteis foram 0,1g do pó, 70ºC e 5min. A temperatura de 220ºC e o tempo de 5 minutos foram os de maior eficiência para a dessorção. A cromatografia gasosa foi conduzida em coluna capilar, detecção por ionização de chama e identificação por espectrometria de massas. A análise dos espectros de massas obtidos para os nove compostos voláteis predominantes indicou a presença de ar-curcúmeno, ar-turmerona, zingibereno, beta-sesquifelandreno, sabineno, 1,8-cineol e 1,4-terpineol.Volatile compounds from turmeric (Curcuma longa L. cultived in Brazil were isolated by solid phase microextraction. The rhizomes were cooked in 0.1% sodium bicarbonate solution, sliced, dried and ground. Polydimethyldiloxanes fibers (100 mm diameter were exposed to the headspace of 10 mL flasks with the aim of establishing an ideal microextraction system. The influence of the following parameters on the volatile substances obtained was studied: powder samples (0.1 to 1.0 g and dissolved samples (40 mg/L, different temperatures (40 to 70ºC and partition periods (2 to 20 min. The effect of temperature (210 to 240ºC and time (3 to 5 min on desorption efficiency was also evaluated. Optimum conditions for the

  3. Identificação e quantificação de voláteis de café através de cromatografia gasosa de alta resolução / espectrometria de massas empregando um amostrador automático de "headspace" Identification and quantification of coffee volatile components through high resolution gas chromatoghaph/mass spectrometer using a headspace automatic sampler

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    Leonardo César AMSTALDEN

    2001-01-01

    Full Text Available Usando um amostrador automático, os "headspaces" de três marcas comerciais de café torrado e moído foram analisados qualitativa e quantitativamente quanto a composição dos voláteis responsáveis pelo aroma através da técnica de cromatografia gasosa/espectrometria de massas. Uma vez que a metodologia não envolveu isolamento ou concentração dos aromas, suas proporções naturais foram mantidas, além de simplificar o preparo das amostras. O emprego do amostrador automático permitiu também boa resolução dos picos cromatográficos sem o emprego de criogenia, contribuindo para redução no tempo de análise. Noventa e um componentes puderam ser identificados, sendo que alguns compostos conhecidos como presentes em café como o dimetilsulfeto, metional e furfuril mercaptana não foram detectados. Os voláteis presentes em maior concentração puderam ser quantificados com o auxílio de dois padrões internos. A técnica se provou viável, tanto para caracterização como para quantificação de voláteis de café.Employing an automatic headspace sampler, the headspaces of three commercial brands of ground roasted coffee were qualitatively and quantitatively analyzed by gas chromatography / mass spectrometry. Since the methodology did not involve aroma isolation or concentration, their natural proportions were maintained, providing a more accurate composition of the flavors, and simplifying sample preparation. The automatic sampler allowed good resolution of the chromatographic peaks without cryofocusing the samples at the head of the column during injection, reducing analysis time. Ninety one compounds were identified and some known coffee volatiles, such as dimethyl sulphide, methional and furfuryl mercaptan were not detected. The more concentrated volatiles could be identified using two internal standards. The technique proved viable, for both characterization and for quantification of coffee volatiles.

  4. Determinação de Mn e Zn em arroz empregando espectrometria de fluorescência de raios x de energia dispersiva

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    Alete Paixão Teixeira

    2012-01-01

    Full Text Available A simple, fast and inexpensive method was developed to determine essential elements in pellets of rice samples using energy dispersive X-ray fluorescence spectrometry (EDXRF. The accuracy and precision were evaluated using Standard Reference Material (rice flour NIST 1568a, and yielding relative standard deviation below 5%. The paired t-test showed good agreement within 95% confidence values. The detection limits (3σ of Mn and Zn were 5.1 and 2.2 mg kg-1, respectively. The proposed method proved to be effective when used to determine Mn and Zn in commercial samples of rice without go by stage of decomposition.

  5. Caracterização de heteropolissacarídeos por espectrometria de massa

    OpenAIRE

    Gonçalves, Virgínia Maria Ferreira

    2007-01-01

    O trabalho de investigação elaborado no âmbito desta dissertação de Mestrado, teve como objectivo a aplicação da Espectrometria de Massa (MS) utilizando métodos de ionização por electrospray (ESI) e ionização por desorção por laser assistida por matriz (MALDI), para a caracterização dos heteropolissacarídeos gelanas e xilanas. Neste trabalho foi efectuada a caracterização de duas gelanas, uma gelana comercial e uma gelana modificada JB3, por ESI MS e espectrometria de mas...

  6. Técnicas modernas em espectrometria de massas aplicadas no isolamento de bioherbicidas produzidos por microrganismos

    OpenAIRE

    Tânia Petta

    2008-01-01

    Neste trabalho foi empregada uma metodologia rápida e eficiente para a identificação de metabólitos fitotóxicos produzidos por microrganismos. O isolamento do composto bioativo foi guiado através de bioensaio com Lemna minor. A espectrometria de massas, em especial o LC-MS, foi utilizada para acelerar o processo de identificação do composto ativo. As bactérias estudadas eram simbióticas do fungo fitopatogênico Sclerotium rolfsii. Seus respectivos extratos orgânicos obtidos de culturas em meio...

  7. Study of a hybrid system using solid oxide fuel cells (SOFC) and gas turbine; Estudo de um sistema hibrido empregando celula de combustivel de oxido solido (SOFC) e turbina a gas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Antonio Carlos Caetano de; Gallo, Giulliano Batelochi; Silveira, Jose Luz [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia. Dept. de Energia], e-mail: caetano@feg.unesp.br

    2004-07-01

    In this paper a hybrid solid oxide fuel cell (SOFC) system, applying a combined cycle using gas turbine for rational decentralized energy production is analyzed. The relative concepts about the fuel cell are presented, followed by some chemical and technical information such as the change of Gibbs free energy in isothermal fuel oxidation directly into electricity. This represents a very high fraction of the lower heating value (LHV) of a hydrocarbon fuel. In the next step a methodology for the study of SOFC and gas turbine system is developed, considering the electricity and steam production for a hospital. This methodology is applied to energetic analysis. Natural gas is considered as a fuel. A Sankey Diagram shows that the hybrid SOFC system is a good opportunity to strengthen the decentralized energy production in Brazil. It is necessary to consider that the cogeneration in this version also is a good technical alternative, demanding special methods of design, equipment selection and contractual deals associated to electricity and fuel supply. (author)

  8. O estado da arte na determinação de resíduos de medicamentos veterinários em alimentos de origem animal empregando técnicas cromatográficas acopladas à espectrometria de massas

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    Osmar D. Prestes

    2013-01-01

    Full Text Available The determination of veterinary drug residues in foods of animal origin is an important issue because of the risk these compounds pose to human health in addition to their persistence and tendency to bioaccumulate. In recent years, significant progress has been made in the area and this review presents the state of the art in sample preparation procedures associated with chromatographic techniques coupled to mass spectrometry for multiresidue determination of veterinary drugs in food of animal origin at concentration levels suitable for the control of residues and contaminants in food.

  9. Um novo método para quantificar mercúrio orgânico (Hg orgânico empregando a espectrometria de fluorescência atômica do vapor frio

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    Márcia Cristina Bisinoti

    2006-12-01

    Full Text Available In this work a simple and sensitive procedure to extract organic mercury from water and sediment samples, using methylene chloride in acidic media followed by CVAFS quantification has been developed. The method was evaluated for possible interferents, using different inorganic mercury species and humic acid, no effects being observed. The detection limit for organic mercury was 160 pg and 396 pg for water and sediment samples respectively. The accuracy of the method was evaluated using a certified reference material of methylmercury (BCR-580, estuarine sediment. Recovery tests using methylmercury as surrogate spiked with 1.0 up to 30.0 ng L-1 ranged from 90 up to 109% for water samples, whereas for sediments, recoveries ranged from 57 up to 97%.

  10. Evaluation of analyte additions method for sodium determination in fuel ethanol by flame atomic emission spectrometry; Avaliacao do metodo das adicoes de analito para a determinacao de sodio em alcool combustivel por espectrometria de emissao atomica em chama

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Adriana Paiva de; Okumura, Leonardo Luiz; Gomes Neto, Jose Anchieta [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2002-07-01

    The analyte additions method was applied for sodium determination in fuel ethanol by atomic emission spectrometry. Graphics involving emission intensity versus analyte concentration in the 0 - 0.300 mg Na L{sup -1} interval concentration range containing 2.1 g K L{sup -1} as an ionisation buffer. Twenty samples of commercial fuel ethanol were collected in different gas stations located in Araraquara city, analyzed and results obtained varied from 0.0072 to 1.55 mg Na L{sup -1}. The limits of detection (L.O.D.) varied from 0.0026 to 0.0239 mg Na L{sup -1}. Recoveries varied in the 95 - 104 % interval. The relative standard deviations (n=12) for three analyte additions in all samples were {<=}4,1 %. (author)

  11. Determinação dos teores de minerais em sucos de frutas por espectrometria de emissão óptica em plasma indutivamente acoplado (ICP-OES Minerals determination in juices by inductively coupled plasma optical emission spectrometry

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    Marcelo Antônio MORGANO

    1999-12-01

    Full Text Available Dois métodos de preparação de amostra para determinação de minerais em suco de uva foram comparados: extração com ácido clorídrico a frio com agitação e digestão em sistema fechado, sob pressão, empregando-se energia de microondas. As concentrações dos minerais foram obtidas empregando-se a técnica de Espectrometria de Emissão Óptica em Plasma Indutivamente Acoplado (ICP-OES. Os teores dos minerais Ca, P, Na, K, Mg, Zn, Fe, Mn e Cu não diferiram significativamente ao nível de 5% (Teste F para as duas metodologias empregadas. A precisão e exatidão dos métodos foi avaliada usando o suco de uva. A metodologia de extração com ácido clorídrico foi empregada para a determinação dos teores de minerais em sucos processados de abacaxi, acerola, caju, goiaba, manga, maracujá e uva. Para facilitar a interpretação dos teores dos minerais encontrados, foram utilizadas as técnicas de Análise por Componentes Principais (PCA e Análise Hierárquica por Agrupamento (HCA.Two sample preparation methods for the determination of minerals from grape juice were investigated for the purpose of methodological evaluation: using hydrochloric acid by shaking, and digestion in closed system, under pressure, using microwave power. The concentrations of minerals were evaluated by the technique of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The minerals contents of Ca, P, Na, K, Mg, Zn, Fe, Mn, and Cu did not differ significantly at the level of 5% (it Tests F for both methodologies used. The precision and accuracy of both methodologies were evaluated using grape juice. The extraction methodology with hydrochloric acid was used for the determination of mineral amounts in processed juices from pineapple, acerola, cashew, guava, mango, passion fruit and grape. To enhance the interpretation of the amounts of minerals, from a nutritional point of view, techniques of Principal Components Analysis (PCA and Hierarchic Cluster

  12. Evaluacion de la precision intralaboratorio para la determinacion simultanea de ocho elementos en muestras geologicas aplicando la espectrometria de emision atomica con plasma acoplado

    National Research Council Canada - National Science Library

    Argota-Coello, Humberto; Fernandez-Heredia, Angel

    2012-01-01

    ... atomica (1); sin embargo la velocidad de respuesta del laboratorio estaba limitada, por lo que se decidio la compra de un equipo de espectrometria de emision atomica con plasma inductivamente acoplado (ICP-AES), para realizar el analisis simultaneo de estos 8 elementos (2). En breve tiempo el laboratorio multiplico su capacidad ana...

  13. AGROTÓXICOS EM MILHO: OTIMIZAÇÃO E VALIDAÇÃO DE MÉTODO MULTIRRESÍDUO EMPREGANDO GC-MS/MS

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    Janice de Fátima Facco

    2013-01-01

    Devido à complexidade da sua matriz, métodos mais eficientes para a determinação de resíduos de agrotóxicos em milho têm sido estudados. O uso do método QuEChERS, juntamente com a técnica de precipitação a baixa temperatura tem apresentado vantagens para a redução de lipídios durante o preparo de amostra de matrizes com alto teor de gordura. Neste estudo, otimizou-se e validou-se um método multirresíduo para determinação de agrotóxicos em milho empregando QuEChERS e GC-MS/MS...

  14. Simulação computacional de sistemas gás-líquido em regime transiente empregando o modelo de mistura

    OpenAIRE

    2016-01-01

    Este trabalho propõe um solver de Riemann do tipo Roe aplicado à sistemas bifásicos gás-líquido em regime transitório empregando-se o modelo de mistura (drift-flux). Para tanto, iniciou-se o desenvolvimento deste a partir de um solver mais simples capaz de simular problemas de acústica. Num segundo estágio adaptou-se o solver para a resolução de três equações não lineares das leis de conservação em sistemas monofásicos utilizando-se gás ideal. Por fim o solver foi direcionado à resolução de s...

  15. Medidas antropométricas na introdução da sonda nasogástrica para nutrição enteral empregando a esofagogastroduodenoscopia

    OpenAIRE

    2013-01-01

    RACIONAL: O correto posicionamento da sonda nasogástrica para nutrição enteral tem sido alvo de várias investigações, demonstrando as controvérsias e a complexidade do procedimento. OBJETIVO: Prever as medidas antropométricas para realizar a inserção de sonda para nutrição enteral até o estômago empregando a esofagogastroduodenoscopia para calcular-se o comprimento necessário até o estômago. MÉTODO: Medidas externas foram obtidas entre a ponta do nariz vs lobo da orelha vs apêndice xifóide vs...

  16. Doseamento microbiológico de vancomicina - desenvolvimento e validação de método empregando leitura cinética em microplacas

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    Túlia de Souza Botelho

    2011-01-01

    O ensaio turbidimétrico tem como princípio a redução da densidade óptica em suspensões microbianas, decorrente o incremento na concentração do antibiótico. No ensaio convencional trabalha-se com tubos de ensaio que demandam longo tempo para visualização da resposta. Assim, o método empregando microplacas com leitura cinética para a dosagem de antibióticos é de interesse considerável, uma vez que possibilita reduzir quantidade de material e tempo de análise necessários e permite o ensaio de gr...

  17. Identificação de proteínas da região cambial de Eucalyptus grandis por eletroforese bidimensional e espectrometria de massas

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    Paola Alejandra Fiorani Celedon

    2006-01-01

    A proteômica expandiu-se dentro da área biológica a partir da década de 90 com o desenvolvimento de técnicas de ionização branda que permitem analisar macromoléculas por espectrometria de massas (MS) e é uma nova estratégia na busca de genes de interesse e de informações sobre o controle da expressão gênica para a manipulação genética de plantas. Na busca por genes diferencialmente expressos durante o desenvolvimento da madeira, foi estabelecida uma plataforma 2D-LC-MS/MS (eletroforese bidim...

  18. Marcadores séricos e espectrometria de massa no diagnóstico do câncer Serum markers and mass spectrometry in the diagnosis of cancer

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    Paulo Costa Carvalho

    2006-12-01

    Full Text Available Esta revisão abrange as principais técnicas, limitações e utilidades da espectrometria de massa aplicada à análise de fluidos biológicos para buscar biomarcadores com potencialidade de diagnóstico médico. Atualmente esse método é capaz de discernir, em segundos, padrões moleculares diferencialmente expressos entre indivíduos controles e com câncer. Resultados da literatura apontam a espectrometria de massa como metodologia promissora no futuro do diagnóstico.This manuscript reviews mass spectrometry methods and limitations for analisys of biological fluids in the search for biomarkers that can aid medical diagnosis. Currently, mass spectrometry has the ability to discriminate differentially expressed molecular patterns among cancer patients and control subjects. Results in the literature point mass spectrometry as having a major role in the future of medical diagnosis.

  19. Identificação de compostos voláteis de maçãs (Malus domestica cultivar Fuji, por cromatografia gasosa-espectrometria de massas

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    JANZANNTTI Natália S.

    2000-01-01

    Full Text Available Os compostos voláteis da maçã cultivar Fuji foram estudados durante 2 anos consecutivos (1994 e 1995. O isolamento dos compostos voláteis da maçã Fuji foi feito utilizando-se uma técnica de enriquecimento dos voláteis do "headspace" em Porapak Q e eluição com hexano. Foram detectados 84 componentes voláteis na maçã Fuji, por cromatografia gasosa de alta resolução, dos quais trinta foram identificados por cromatografia gasosa-espectrometria de massas, aliada aos índices de Kovats. Os compostos majoritários foram os ésteres acetato de butila, acetato de 2-metil butila, acetato de hexila e o terpeno µ-farneseno. A classe química predominante, entre compostos voláteis na maçã Fuji, foi a dos ésteres.

  20. Aplicação de métodos quimiométricos na investigação do metaboloma de eucalipto por técnicas cromatográficas multidimensionais e hifenadas à espectrometria de massas

    OpenAIRE

    2014-01-01

    O presente trabalho é dedicado à aplicação de técnicas cromatográficas multidimensionais à problemas complexos de separação. No primeiro conjunto de estudos foram desenvolvidos métodos analíticos para investigação do metaboloma de plantas de interesse comercial. Para isso, foram utilizadas a cromatografia gasosa bidimensional abrangente (GC×GC-MS) e a cromatografia líquida de ultra eficiência (UHPLC-MS) acopladas à espectrometria de massas para aquisição do perfil metabólico de folhas de euca...

  1. Desenvolvimento de estratégias analíticas envolvendo microextração dispersiva e sistema em linha empregando extração no ponto-nuvem para a determinação de metais

    OpenAIRE

    Baliza, Patrícia Xavier

    2009-01-01

    No presente trabalho, é proposta a síntese de um novo reagente derivado do tiazol, o 5-bromotiazolilazo-2-orcinol (Br-TAO) e a sua aplicação em sistemas de pré-concentração de metais. O Br-TAO foi empregado em um procedimento para a pré-concentração de cobalto utilizando a micro-extração dispersiva líquido-líquido e determinação por espectrometria de absorção atômica com chama (FAAS). O fator de enriquecimento e o limite de detecção obtidos foram 16 e 0,9 µg L-1, respectivam...

  2. Cultivo hidropônico da alface empregando substratos: uma alternativa a NFT? Growing lettuce plants in hydroponics using substrates: an alternative for the NFT?

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    Jerônimo L. Andriolo

    2004-12-01

    Full Text Available Foi desenvolvido um dispositivo experimental para o cultivo da alface em sistema hidropônico fechado empregando substratos. As bancadas foram constituídas por telhas de cimento amianto, cujos canais foram preenchidos com brita basáltica. Sobre a brita foram dispostos os substratos, formando uma camada de 0,05 m de altura, com a superfície revestida com filme de polietileno opaco branco. As mudas foram produzidas em bandejas de poliestireno e plantadas em orifícios feitos sobre a superfície do filme de polietileno. Uma solução nutritiva completa foi fornecida diariamente, por meio de tubos gotejadores localizados na superfície da camada de substrato e abaixo do filme de polietileno. A solução drenada foi recolhida por gravidade para dentro do reservatório principal. Foram conduzidos dois experimentos, no período entre 16 de maio e 24 de junho e 1º e 28 de outubro de 2003, empregando as cultivares Regina e Mimosa e os substratos areia média e substrato orgânico Plantmax® Folhosas HA. No decorrer dos experimentos, houve diminuição dos valores de pH da solução nutritiva, tendo sido feita apenas uma correção em cada um dos experimentos. No dia mais quente do experimento de primavera, a temperatura foi mais elevada na areia, sem diferença significativa do substrato orgânico, cuja média situou-se 5,4ºC acima da temperatura da solução nutritiva e 0,4ºC acima daquela do ar. As médias mais elevadas das variáveis de crescimento e desenvolvimento foram observadas no substrato orgânico no outono, enquanto, na primavera, foram constatadas nos tratamentos tendo areia como substrato. O emprego dos substratos permitiu uma redução em torno de 92,4% no tempo de funcionamento da motobomba e simplificou tanto o manejo da fertirrigação como os controles da solução nutritiva.An experimental set-up to grow lettuce plants in a closed hydroponic growing system using substrates was made up and tested. Commercial fibber cement tiles

  3. Desenvolvimento de procedimento analítico automático para determinação espectrofotométrica de microcistinas em águas empregando o processo de multicomutação em fluxo

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    Gláucia Pessin Vieira

    2009-01-01

    Neste trabalho, propõe-se o desenvolvimento de procedimento analítico automático para determinação espectrofotométrica de microcistinas em águas empregando o processo de multicomutação em fluxo. O módulo de análise para implementar o procedimento analítico empregou um bomba de seringa para propulsão de fluído e válvulas solenóide para controlar a amostragem. A bomba de seringa foi construída no laboratório de Química Analítica, CENA/USP, onde foi empregado um motor de passo para fazer o deslo...

  4. Desenvolvimento de procedimento analítico empregando multicomutação em fluxo para determinação fotométrica de cloreto em amostras de coque de petróleo

    OpenAIRE

    Andréia Cardoso Pereira

    2010-01-01

    Neste trabalho foi desenvolvido um procedimento analítico empregando o processo de multicomutação para determinação de íons cloreto com detecção fotométrica para aplicação em amostras de coque de petróleo. O procedimento foi baseado no método espectrofotométrico descrito no Standard Methods, onde a reação entre tiocianato de mercúrio (II) e cloreto leva ao deslocamento dos íons tiocianato e à formação de um complexo de coloração vermelha com o Fe (III), que foi monitorado em 455 nm. Foram con...

  5. Determination of aflatoxins M1, M2, B1, B2, G1 and G2 in peanut by modified QuEChERS method and ultra-high performance liquid chromatography-tandem mass spectrometry | Determinação de aflatoxinas M1, M2, B1, B2, G1 e G2 em amendoim utilizando um método QuEChERS modificado e cromatografia líquida de ultraeficiência com detecção por espectrometria de massas sequencial

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    Juliana Swensson de Mattos

    2015-08-01

    Full Text Available A suitable method for routine analysis of aflatoxins M1, M2, B1, B2, G1, G2 in peanut by ultra-high performance liquid chromatography-tandem mass spectrometry was developed and validated. The sample preparation was performed using a triple partitioning (water/acetonitrile/hexane modified Quick Easy Cheap Effective Rugged and Safe (QuEChERS method. For the first time, this method is reportedly used for aflatoxins analysis in peanut. Satisfactory recoveries ranged from 71 to 101%, with relative standard deviation lower than 15% were obtained for the target aflatoxins. The determination coefficients were ≥ 0.99 which showed good linearity. The LOD and LOQ varied from 0.03 to 0.26 ng g-1 and 0.1 to 0.88 ng g-1, respectively. The validated method was successfully applied to for the determination of aflatoxins in ten peanut samples. Total aflatoxin concentration exceeded the maximum level permitted by the Brazilian regulation in one sample of roasted peanut, while aflatoxins M1 and M2 were detected respectively in three and in one of the samples. The results strongly suggest that peanuts and peanut products should be continuously monitored for the aflatoxins investigated in this work. ---------------------------------------------------------------------------------------------- Um método adequado para a análise de rotina de aflatoxinas M1, M2, B1, B2, G1, G2 em amendoim por cromatografia líquida de ultraeficiência com espectrometria de massas foi desenvolvido e validado. A preparação da amostra foi realizada utilizando um método QuEChERS (Quick Easy Cheap Effective Rugged and Safe modificado, empregando partição tripla (água/acetonitrila/hexano. Pela primeira vez este método foi utilizado para análise de aflatoxinas em amendoim. Recuperações satisfatórias, entre 71 e 101%, com coeficientes de variação inferiores a 15%, foram obtidas para as aflatoxinas estudadas. Os coeficientes de determinação foram ≥ 0,99, demostrando boa

  6. Determinação de nitrito/nitrato e amônio/fosfato em sistema de analise em fluxo, empregando o conceito da multicomutação e amostragem binária

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    J. L. O. Santos

    2014-11-01

    Full Text Available Os sistemas de análise em fluxo foram propostos visando a mecanização de procedimentos analíticos, permitindo realizar com eficiência tarefas previamente executadas pelo analista e aumentar a quantidade de amostras que poderiam ser processadas por unidade de tempo. Desde então a maioria das etapas envolvidas em procedimentos analíticos como amostragem, adições de reagentes, separações, diluições, pré-concentrações, etc em sido desenvolvidos. O presente trabalho apresenta o desenvolvimento de procedimentos analíticos em fluxo empregando o conceito de multicomutação e amostragem binária com detecção espectrofotométrica para a determinação de nitrito/nitrato, amônio/fosfato e, seu emprego na avaliação preliminar das águas do Rio Grande, que recebe uma grande quantidade de aporte antropico (esgoto in natura de vários bairros da cidade de Barreiras-BA. Os sistemas em fluxo proposto se mostraram robustos e flexível para a determinação dos analitos estudados, sendo possível a determinação de diferentes espécies.com o mesmo módulo de análise alterando-se apenas a estrutura lógica (programação ou gerenciamento do módulo de análise. Entre os resultados obtidos nas análises, foi possível se obter parâmetros preliminares de concentração das espécies do rio Grande.

  7. Degradação fotocatalítica de efluentes de indústria têxtil empregando TiO2 e Nb2O5, sob irradiação visível

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    Veronice Slusarski Santana

    2002-04-01

    Full Text Available A aplicação de métodos biológicos convencionais de tratamento de efluentes têxteis está limitada pela degradação insatisfatória de alguns corantes. Assim, a fotocatálise heterogênea é uma alternativa no tratamento desse tipo de efluente. Foram realizados testes de degradação fotocatalítica em três efluentes naturais de indústria têxtil, sob irradiação visível, empregando os fotocatalisadores: TiO2, Nb2O5 puros e em combinação, através da mistura mecânica (1:1 e impregnação (5%Nb2O5/TiO2. As análises de caracterização realizadas (RTP, DRS, acidez, FTIR e análise textural indicaram um efeito sinérgico e interação diferenciada entre os óxidos e a formação de uma nova fase no catalisador Nb2O5-TiO2. Os resultados de descoloração e mineralização mostraram que a redução de cor não está diretamente relacionada com a redução de DQO, e que a eficiência do processo fotocatalítico depende tanto do efluente a ser tratado quanto do fotocatalisador empregado, tornando-se promissor o uso do Nb2O5 e irradiação visível na fotodegradação de efluentes têxteis.

  8. Otimização das condições de extração de senosídeos por soluções hidroetanólicas das folhas de Senna alexandrina MILL empregando planejamento fatorial

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    Alexandre de Almeida Lopes Severo

    2013-12-01

    Full Text Available Senna alexandrina MILL é um arbusto alto, originário da Arábia, amplamente cultivado na Índia e largamente utilizado como laxativo na constipação aguda e em casos em que a defecação é aconselhável, como após intervenção cirúrgica antes ou depois de operação abdominal, sendo empregado na forma de pós, xaropes, comprimidos e cápsulas. Como estas formulações geralmente são preparadas à partir de derivados do extrato líquido, torna-se fundamental para a qualidade e eficácia que este tenha seu processo de extração otimizado. O presente trabalho teve por objetivo determinar as melhores condições de extração, por soluções hidroetanólicas, das folhas de Senna alexandrina, empregando planejamento fatorial completo com ponto central 23 (três fatores e dois níveis onde os níveis dos fatores foram codificados como -1 (baixo, 0 (ponto central e 1 (alto, e metodologia de superfícies de respostas, para avaliar a influência do solvente, da quantidade de planta e do método de extração sobre o teor de derivados hidroxiantracênicos expressos em senosídeo B (SB e sobre o resíduo seco (RS nos extratos líquidos preparados. Foram realizados planejamentos experimentais completos, sendo um realizado pelo deslocamento dos níveis, após a análise do primeiro planejamento. Após a análise da superfície de resposta do planejamento com os níveis deslocados encontrou-se a faixa de melhor extração dos derivados hidroxiantracênicos expressos em senosídeo B com a melhor relação SB/RS, utilizando o solvente etanol/água a 60% V/V, 15 gramas da planta, e extração com aquecimento e agitação.

  9. Determination of amoxicillin content in powdered pharmaceutical formulations using DRIFTS and PLS Determinação de amoxicilina em formulações farmacêuticas em pó empregando DRIFTS-PLS

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    Graciele Parisotto

    2007-03-01

    Full Text Available The amount of amoxicillin in pharmaceutical formulations was determined using spectra of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS, in association with partial least squares (PLS regression. The spectra of 24 different samples (17 for the calibration set and 7 for the validation set, which had been registered using a Nicolet Magna 550 spectrophotometer, contained 76.7-94.3% of amoxicillin in starch. The PLS models were constructed with auto-scaled or variance-scaled data, and multiplicative scatter correction (MSC. The best model presented R²=0.9936, RMSEC=0.441 and RMSEV=0.790. The analytical method proposed is non-destructive and the cost and time of analysis are very much reduced, allowing for the fast and direct determination of amoxicillin content.Neste trabalho propõe-se a quantificação de amoxicilina em formulações farmacêuticas empregando espectroscopia por refletância difusa no infravermelho com transformada de Fourier (DRIFTS e regressão por mínimos quadrados parciais (PLS. Foram coletados em um espectrômetro Nicolet Magna 550 os espectros de 24 amostras (17 para o conjunto de calibração e 7 para o conjunto de validação contendo de 76,7-94,3 % de amoxicilina em amido. Para a construção dos modelos PLS foi empregada a correção do espalhamento de luz (MSC e os dados foram autoescalados ou escalados pela variância. Foi obtido um excelente modelo para a previsão da amoxicilina o qual apresentou R²=0,9936, RMSEC=0,441 e RMSEV=0,790. O método proposto além de não destrutivo apresenta baixo tempo de análise e baixo custo podendo ser facilmente empregado no controle de qualidade das indústrias farmacêuticas.

  10. Isotope determination of sulfur by mass spectrometry in soil samples Determinação isotópica de enxofre por espectrometria de massas (irms em amostras de solo

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    Alexssandra Luiza Rodrigues Molina Rossete

    2012-12-01

    Full Text Available Sulphur plays an essential role in plants and is one of the main nutrients in several metabolic processes. It has four stable isotopes (32S, 33S, 34S, and 36S with a natural abundance of 95.00, 0.76, 4.22, and 0.014 in atom %, respectively. A method for isotopic determination of S by isotope-ratio mass spectrometry (IRMS in soil samples is proposed. The procedure involves the oxidation of organic S to sulphate (S-SO4(2-, which was determined by dry combustion with alkaline oxidizing agents. The total S-SO4(2- concentration was determined by turbidimetry and the results showed that the conversion process was adequate. To produce gaseous SO2 gas, BaSO4 was thermally decomposed in a vacuum system at 900 ºC in the presence of NaPO3. The isotope determination of S (atom % 34S atoms was carried out by isotope ratio mass spectrometry (IRMS. In this work, the labeled material (K2(34SO4 was used to validate the method of isotopic determination of S; the results were precise and accurate, showing the viability of the proposed method.O enxofre tem papel essencial em plantas, sendo um dos principais nutrientes em diversos processos metabólicos; ele apresenta quatro isótopos estáveis (32S, 33S, 34S e 36S, com abundância natural de 95,00, 0,76, 4,22 e 0,014 % em átomos, respectivamente. Desenvolver um método para determinação isotópica do S por espectrometria de massas de razão isotópica (IRMS em amostras de solo foi o objetivo deste trabalho. A oxidação de S orgânico a sulfato (S-SO4(2- foi avaliada utilizando a oxidação via seca com agentes oxidantes alcalinos. A concentração S-SO4(2- foi determinada pelo método turbidimétrico, e os resultados mostraram que o processo de conversão foi adequado. A obtenção do gás SO2 foi por decomposição térmica do BaSO4 em uma linha de vácuo a 900 ºC, em presença de NaPO3. A determinação isotópica do S (% em átomos de 34S foi realizada em um espectrômetro de massa (IRMS. Neste trabalho, a

  11. Comparing the prevalence rates of social phobia in a community according to ICD-10 and DSM-III-R Comparando estimativas de prevalência da fobia social na comunidade empregando-se a CID-10 e a DSM-III-R

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    Fábio Lopes Rocha

    2005-09-01

    Full Text Available OBJECTIVE: This population-based study aimed to compare the prevalence rates of social phobia using DSM-III-R and CID-10, based on the Composite International Diagnostic Interview (CIDI, in a Brazilian community. METHODS: This survey was carried out in a representative sample of 1,041 residents from Bambuí, Minas Gerais, Brazil (attrition rate = 14.7%. The Brazilian version of the CIDI was used. One-month, one-year and lifetime social phobia prevalence rates were estimated, employing the DSM-III-R and ICD-10 classifications, using the CIDI computer program. RESULTS: One-month, one-year, and life prevalence rates of social phobia, based on the DSM-III-R (7.9, 9.0 and 11.7% respectively were higher than those based on the ICD-10 (4.7, 5.2 and 6.7% respectively; p OBJETIVO: Este estudo populacional visa comparar estimativas de prevalência de fobia social empregando-se a CID-10 e a DSM-III-R em uma comunidade brasileira. MÉTODOS: O levantamento foi realizado em uma amostra representativa de 1.041 residentes de Bambuí, Minas Gerais, Brasil (perda = 14,7%. Foi utilizada a versão brasileira da Composite International Diagnostic Interview (CIDI. As prevalências de 1 mês, 1 ano e vida foram estimadas empregando-se as classificações CID-10 e DSM-III-R, utilizando-se o programa de computador da CIDI. RESULTADOS: As prevalências de 1 mês, 1 ano e vida da fobia social, baseadas na DSM-III-R (7,9, 9,0 e 11,7% respectivamente foram mais elevadas que aquelas baseadas na CID-10 (4,7, 5,2 e 6,7%, respectivamente; p < 0,01 para todos. CONCLUSÃO: Nossos resultados reforçam a hipótese de que as taxas de prevalência de fobia social são mais elevadas quando baseadas na DSM-III-R em comparação com a CID-10.

  12. Avaliação do risco de contaminação da água subterrâneas na região oeste da Bahia pelo inseticida carbofuran empregando os modelos Attenuation Factor (AF e Retardation Factor (RF

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    J. L. O. Santos

    2014-11-01

    Full Text Available Neste trabalho realizou-se estudos do potencial de contaminação de água subterrânea pelo  inseticida carbofuran (2,3-dihidro-2,2-dimetilbenzenofuran-7-metilcarbamato, pela estimativa da lixiviação no perfil de 0 -10 cm e 10-20 cm do latossolo de uma área de plantio de soja, milho e algodão no município de Barreiras, região Oeste da Bahia. Os parâmetros de lixiviação foram avaliados empregando os modelos Attenuation Factor (AF e Retardation Factor (RF, dois índices usados como indicadores do potencial de contaminação de água subterrânea. Com base nos valores estimados pelos modelos, verificou-se que do total do aporte de pesticidas que atinge o solo, 35% se concentrou a 10 cm de profundidade. Deste, 26% consegue se difundir até a profundidade de 20 cm do perfil do solo. Os resultados estimados pelos modelos demonstraram a probabilidade de contaminação das águas subterrâneas pela lixiviação do carbofuran.

  13. Avaliação de características dos ácidos húmicos de resíduos de origem urbana: II. métodos termodegradativos (pirólise acoplada à cromatografia gasosa / espectrometria de massa

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    L. P. Canellas

    2000-12-01

    Full Text Available Este trabalho objetivou investigar as principais unidades estruturais de ácidos húmicos obtidos do composto de resíduos sólidos urbano (AH-CRSU e lodo de estação de tratamento de esgoto (AH-LETE por meio da pirólise acoplada à cromatografia gasosa / espectrometria de massas. Os ácidos húmicos extraídos do lodo da estação de tratamento de esgotos apresentaram maior quantidade de mono e diaril ésteres de massa mais elevada. Os n-alcanos presentes nos AH-LETE revelaram-se de cadeia mais curta do que nos AH-CRSU. Foram incorporados na estrutura dos AH fragmentos de ftalatos, provavelmente em virtude da contaminação da matéria orgânica por plásticos. Os compostos aromáticos presentes nos AH-LETE originaram-se, principalmente, de derivados do naftaleno e derivados do benzeno com substituição por cadeias alifáticas maiores do que AH-CRSU. Os compostos nitrogenados presentes mostraram-se essencialmente heteroaromáticos e os oxigenados furanos substituídos originados da degradação de carboidratos. Os compostos oxiaromáticos predominantes foram fenóis substituídos.

  14. Determinação de elementos essenciais maiores e traço em queijos por espectrometria de emissão atômica com plasma de argônio induzido após digestão parcial Determination of minerals and trace elements in cheese by inductively-coupled plasma optical emission spectrometry after partial digestion

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    Carmen Silvia Kira

    2007-09-01

    Full Text Available Concentrações de Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P e Zn foram determinadas em amostras de quatro tipos de queijo (mussarela, minas, prato e parmesão por espectrometria de emissão atômica com plasma de argônio acoplado indutivamente após dissolução parcial (hidrólise com HCl e total da matéria orgânica (digestão por via seca. As concentrações da maioria dos elementos essenciais maiores e traço, usando o método de dissolução parcial, foram consideradas estatisticamente iguais às obtidas com o método de dissolução total da matéria orgânica, demonstrando a potencialidade da digestão parcial em análises de rotina.Concentrations of Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P and Zn in four different types of cheese (mozzarella, white cheese, prato and parmesan were analyzed by inductively-coupled plasma optical emission spectrometry (ICP-OES after partial digestion (HCl hydrolysis and total digestion of organic matter (dry ashing. The results obtained for most of the elements analyzed here by the partial digestion (HCl hydrolysis and dry ashing methods were found to be statistically congruent, demonstrating the promising potential of the partial digestion method in routine analyses.

  15. Evaluation of noni (Morinda citrifolia volatile profile by dynamic headspace and gas chromatography-mass spectrometry Avaliação do perfil de voláteis em noni (Morinda citrifolia por headspace dinâmico e cromatografia gasosa-espectrometria de massas

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    Adriana Sousa

    2010-09-01

    Full Text Available Noni is a fruit that has interested the scientific community due to its medicinal and functional activities. Different products that contain noni are already in the market, but their consumption could be impaired by their distinctive unpleasant aroma and flavor. The aim of this work was to evaluate the noni pulp volatile profile by dynamic headspace and gas chromatography-mass spectrometry. Thirty seven volatile compounds were detected, mainly alcohols (63.3%, esters (26.9%, cetones (7.4%, and acids (1.2%.O noni é um fruto que tem interessado à comunidade científica por sua atividade funcional e medicinal. Já se encontram no mercado diferentes produtos que contêm noni em sua composição, mas seu consumo tem sido prejudicado por seu aroma e sabor desagradáveis. O objetivo deste trabalho foi o de avaliar o perfil de voláteis da polpa de noni pela técnica de headspace dinâmico e cromatografia gasosa-espectrometria de massas. Foram detectados 37 compostos voláteis, sendo os principais: alcoóis (63,3%, ésteres (26,9%, cetonas (7,4% e ácidos (1,2%.

  16. Identificação de compostos orgânicos e farmacêuticos em esgoto hospitalar utilizando cromatografia gasosa acoplada a espectrometria de massa Identification of organic and pharmaceutical compositions in hospital wastewater using a gas chromatograph coupled to mass spectrometry

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    Francisco Vieira Paiva

    2011-03-01

    Full Text Available Os resíduos líquidos provenientes dos estabelecimentos assistenciais de saúde são mais complexos do que os esgotos domésticos. Sua composição contém inúmeros compostos farmacêuticos, saneantes, elementos radiativos e de laboratórios. O conhecimento desses compostos pode auxiliar na escolha do tratamento adequado para esses esgotos e diminuir os impactos ambientais nos corpos receptores. A pesquisa foi realizada utilizando um sistema combinado (UASB e lodos ativados para tratar a água residuária de um hospital. Neste trabalho, foram realizadas análises físico-químicas para caracterização do esgoto e cromatografia gasosa acoplada à espectrometria de massa para identificação de compostos químicos farmacêuticos, podendo-se constatar a presença de inúmeros elementos residuais dos fármacos usados no hospital.Liquid waste residues from health care establishments are more complex than those from residential sewage. Their composition contains several pharmaceutical chemical composites, sanitizers, radioactive, and laboratorial elements. Knowing about these composites may aid in choosing the proper treatment for these sewages, and diminish the environmental impact in receptors. The study was carried out in a combined system (UASB and activated sludge to treat a hospital wastewater. In this experiment, material and chemical analyses were employed to trace sewage characteristics and gas chromatography associated with mass spectrometry to identify pharmacologic chemical composites, where innumerous residual elements were found in chromatographs.

  17. Imunodiagnóstico da leptospirose humana através do teste ELISA-IgM, empregando-se diferentes preparações antigênicas a partir de sorotipos prevalentes de Leptospira interrogans Immunodiagnostic of human leptospirosis by ELISA-IgM, employing: different antigenic preparations as from prevalent serovars of Leptospira interrogans

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    Marcos Vinicius da Silva

    1990-08-01

    Full Text Available Realizou-se estudo comparativo de diferentes sorotipos de Leptospira interrogans utilizados na preparação de antígenos empregados no teste ELISA, para a detecção de anticorpos da classe IgM, em amostras de soro na fase precoce e tardia da leptospirose humana. Foram utilizados dez sorotipos, escolhidos entre os que apresentaram maior reatividade na soroaglutinação microscópica (SAM, na cidade de São Paulo. Os cinco sorotipos que apresentaram melhores resultados individualmente no teste ELISA-IgM (canicola, hebdomadis, icterohaemorrhagiae, cynopteri e brasiliensis, foram também estudados em mistura antigênica. Os antígenos não tratados apresentaram maior reatividade do que os antígenos tratados com Triton X - 100 (4% à temperatura de 50ºC, durante 4 horas. O teste ELISA-IgM empregando os sorotipos não tratados, isoladamente, e em mistura antigênica, mostrou-se altamente sensível, podendo ser empregado como teste de triagem para o diagnóstico precoce da leptospirose humana. Outra aplicação do teste é permitir a detecção do início de situações epidêmicas ou de surtos, possibilitando acionar medidas de vigilância epidemiológica.A comparative study among different serovars of Leptospira interrogans was performed in order to prepare antigens to detect IgM antibodies by ELISA in early and late phase of human leptospirosis. Ten serovars were chosen among the most prevalent detected by microscopic seroagglutination (SAM in São Paulo city. Using ELISA-IgM five of them showed better results (canicola, hebdomadis, icterohaemorrhagiae, cynopteri and brasiliensis. These ones were also studied in a pool. The non-treated antigens showed higher reactivity than the Triton X-100 (4%/50ºC/4h. ELISA-IgM using individually or pool of non treated antigens proved to be reliable with high sensitivity and should be used for an earlier diagnosis of leptospirosis, as a trial test. Faster diagnostic elucidation can be useful to detect

  18. Pulicação de métodos de análise multivariada no controle qualitativo de essências alimentícias empregando espectroscopia no infravermelho médio Using multivariate analysis methods in quality control of food essence by mid-infrared spectroscopy

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    Gilson Augusto Helfer

    2006-12-01

    Full Text Available No presente trabalho é apresentada uma nova metodologia para a análise qualitativa de essências alimentícias, empregando espectroscopia por reflexão na região do infravermelho médio associada à análise multivariada. Este método apresenta entre suas principais vantagens: a não destruição da amostra e conseqüente não agressão ao ambiente; e a não necessidade de separação prévia dos seus componentes, que resulta em menor tempo de análise e redução de custos. Para tanto, diferentes lotes de amostras de essências alimentícias de baunilha, de leite, de caramelo, de cereja e de morango foram empregadas para a aquisição dos espectros, visando à construção dos modelos e validação do método. Como resultados mais significativos, foi possível observar que o método empregado, não só discrimina as diferentes essências (em função da composição, mas também a origem e uniformidade delas.In the present work a new methodology for the qualitative analysis of food essences is presented, using a mid-infrared spectroscopy associated to the multivaried analysis. This method presents the main advantages: not to destroy the sample, it has a lower cost, it makes the analysis quicker and does not produce residues. Taking this into account, different lots of samples of food essences of vanilla, milk, caramel, cherry and strawberry were used to acquire the specters with the purpose of developing models and validation of the method. Having more significant results, it can be observed that the used method not only discriminates the different essences (due to the composition, but also the origin and uniformity of the same ones.

  19. Biological effects of light: application of low power therapy using LEDs (Light Emitting Diode on the healing of venous ulcers: a case report Efeitos biológicos da luz: aplicação de terapia de baixa potência empregando LEDs (Light Emitting Diode na cicatrização da úlcera venosa: relato de caso

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    Valdênea Aparecida Bordinassi de Castro

    2009-08-01

    Full Text Available The use of low power light sources, such as diodes emitters of light – LEDs, provides an alternative and complementary therapeutic resource to the conventional ones, with the advantage of being cost-effective and reliable in the treatment of ulcers and other infirmities. This study was carried out on a patient from the HC/UEL Outpatient Clinic with ulcers on both lower limbs. LEDs were applied once a week, using a wave length of 628 nm on the left lower limb ulcer ,using the right limb as control. Evolution was measured through photographic registers, area size and pain assessment. Eighteen sessions were performed. Results showed that changes were observed on the clinical characteristics of the injury and the healed area was 30% larger when compared to the control. As for the pain assessment, the visual analogue scale varied from eight to zero on the limb radiated and from nine to two on the control. Thus, it can be concluded that the LED therapy is a resource of choice for treating venous ulcer, in both healing and pain reduction aspects O emprego de fontes de luz de baixa potência, como diodos emissores de luz-LEDs, pode propiciar um recurso terapêutico opcional aos convencionais ou ser utilizado em conjunto com estes, com a vantagem do baixo custo e comprovada eficiência no tratamento de úlceras e outras enfermidades. O estudo de caso foi realizado com um paciente do Ambulatório de Clinicas do HC/UEL que apresenta úlceras nos membros inferiores. A aplicação foi feita uma vez por semana, empregando LEDs com comprimento de onda de 628 nm na úlcera do membro inferior esquerdo e o direito foi utilizado como controle. A evolução foi medida por meio de registro fotográfico, medida da área e mensuração da dor. Foram realizadas 18 sessões. Os resultados apontaram mudanças nas características clínicas da lesão e a área cicatrizada foi 30% maior em relação à úlcera controle. Quanto à dor, a escala análoga visual variou de

  20. Development and validation of a method for detection and quantification of ochratoxin A in green coffee using liquid chromatography coupled to mass spectrometry Desenvolvimento e validação de metodologia na detecção e na quantificação de Ocratoxina A no café verde utilizando cromatografia líquida acoplada à espectrometria de massas

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    Raquel Duarte da Costa Cunha Bandeira

    2012-12-01

    Full Text Available A method using Liquid Chromatography Tanden Mass Spectrometry (LC-MS/MS with matrix-matched calibration curve was developed and validated for determining ochratoxin A (OTA in green coffee. Linearity was found between 3.0 and 23.0 ng.g-1. Mean recoveries ranged between 90.45% and 108.81%; the relative standard deviation under repeatability and intermediate precision conditions ranged from 5.39% to 9.94% and from 2.20% to 14.34%, respectively. The limits of detection and quantification were 1.2 ng.g-1 and 3.0 ng.g-¹, respectively. The method developed was suitable and contributed to the field of mycotoxin analysis, and it will be used for future production of the Certified Reference Material (CRM for OTA in coffee.Um método utilizando Cromatografia Líquida de Alta Eficiência-Espectrometria de Massas Sequencial (CLAE-EM/EM com curva de calibração em matriz foi desenvolvido e validado para a determinação de ocratoxina A (OTA em café verde. A linearidade foi demonstrada entre 3,0 e 23,0 ng.g-1. As recuperações médias variaram entre 90,45% e 108,81%; o desvio padrão relativo sob condições de repetitividade e precisão intermediária foram de 5,39% e 9,94% e de 2,20% e 14,34%, respectivamente. Os limites de detecção e quantificação foram 1,2 ng.g-1 e 3,0 ng.g-, respectivamente. O método desenvolvido foi adequado, contribuiu para o campo de análises em micotoxinas e será usado para a futura produção de Material de Referência Certificado (MRC para OTA em café.

  1. Análise dos compostos voláteis da aguardente de cana por concentração dinâmica do "headspace" e cromatografia gasosa-espectrometria de massas The analysis of volatile compounds from Brazilian sugar cane spirit by dynamic headspace concentration and gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Ian Carneiro da Cunha Nóbrega

    2003-08-01

    Full Text Available Os compostos voláteis da aguardente de cana foram extraídos por meio da concentração dinâmica do "headspace" em armadilhas contendo Tenax-TA e analisados por cromatografia gasosa-espectrometria de massas. Cerca de 100 compostos voláteis, com número de carbonos que variavam de 5 a 18, foram detectados. Destes, 22 foram selecionados, sendo 18 ésteres, com base nas suas quantidades no extrato ou nas suas características sensoriais obtidas na literatura. Os compostos presentes em maiores quantidades foram o 3-metil-1-butanol (álcool isoamílico, 1,1-dietoxi-etano (acetaldeído dietil acetal e os ésteres acetato de 3-metilbutila, hexanoato de etila, octanoato de etila, decanoato de etila e dodecanoato de etila. Dentre os compostos identificados em menor quantidade, destacou-se, devido a sua natureza química, o composto sulfurado 4,5-de-hidro-2-metil-3(2H-tiofenona. Esta é a primeira vez que este e outros compostos voláteis são reportados em aguardente de cana. Conclui-se que a metodologia empregada neste trabalho permitiu a identificação de compostos voláteis da fração C5-C18, que potencialmente contribuem para o aroma da aguardente de cana.The volatile compounds of Brazilian sugar cane spirit, the fermented and distilled juice of sugar cane, were extracted by dynamic headspace concentration on Tenax-TA trap and analyzed by gas chromatography-mass spectrometry. Approximately 100 volatile compounds with carbon number ranging from 5 to 18 were detected. Among these, 18 esters and 4 compounds from other chemical classes were selected for this work on the basis of their quantity in the extract or their sensory qualities obtained from literature. The major compounds identified were 3-methyl-1-butanol (isoamyl alcohol, 1,1-diethoxy-ethane (acetaldehyde diethyl acetal and the esters 3-methylbutyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and ethyl dodecanoate. In minor quantities, potentially important aroma compounds

  2. Estimativas de um modelo de geração e propagação de ondas empregando campos de vento com diferentes resoluções espaciais e temporais Estimatives of a generation and propagation wave model using wind fields at different spatial and temporal resolution

    Directory of Open Access Journals (Sweden)

    Frederico Francisco Ostritz

    2012-09-01

    Full Text Available O presente trabalho apresenta uma comparação entre algumas rodadas do modelo numérico de geração e propagação de ondas Wavewatch III empregando campos de vento com diferentes resoluções espaciais e temporais em uma região tropical do oceano Atlântico Sul. Os campos de vento utilizados de entrada são os da Reanálise do NCEP (com resolução espacial de cerca de 2º e resolução temporal de 6 horas, do Global Forecast System (resolução espacial de 1º e resolução temporal de 6 horas, bem como os campos de maior resolução espacial e temporal de um modelo de mesoescala (Mesoscale Modeling System, com resolução espacial de 0,2º e resolução temporal de 1 e 6 horas. As estimativas de altura significativa, período de pico e direção principal de propagação do Wavewatch III, assim como as estimativas dos ventos usados como entrada, são comparadas com as medições de ondas de um radar e de um anemômetro, ambos instalados na Bacia de Campos, sudeste do Brasil. Os resultados mostram que campos de vento com maior resolução espacial têm um impacto positivo sobre a previsão das ondas. No entanto, mantendo a mesma resolução espacial e aumentando a resolução temporal, não se obtém melhores estimativas dos campos de onda.This work presents a comparison among several runs of the numerical wave model, Wavewatch III (WW3 employing different temporal and spatial resolutions for the wind fields in a tropical area of the Southern Atlantic Ocean. The input wind fields are from the National Centers for Environmental Prediction (NCEP reanalysis, with 2º spatial resolution and 6 hours temporal resolution, the Global Forecast System (GFS analysis, with 1º spatial resolution and 6 hours temporal resolution, as well as the higher spatial and temporal resolution fields of a mesoscale model (Mesoscale Modeling System, with 0.2º spatial resolution and temporal resolution of 1 and 6 hours. The WW3 estimates of significant wave height

  3. Obtenção de substratos cerâmicos no sistema Si-Al-O-N-C empregando polissiloxanos e carga de Si e Al2O3 Ceramic tapes of Si-Al-O-N-C compounds using mixtures of polyssiloxane and Si-Al2O3 fillers

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    R. M. Rocha

    2005-03-01

    Full Text Available A técnica de processamento de colagem por fita (tape casting tem sido amplamente utilizada na obtenção de cerâmicas para diferentes aplicações: substratos cerâmicos e estruturas planares em multicamadas para circuitos integrados e capacitores; eletrólitos sólidos para células a combustível e sensores; cerâmicas piezoelétricas para atuadores e transdutores; membranas de separação para micro-filtragem; compósitos estruturais e trocadores de calor. Neste trabalho, a técnica convencional de colagem por fita foi adaptada com a utilização do processo de pirólise controlada de misturas de polímeros e carga, empregando-se polissiloxanos e cargas de silício e alumina nas suspensões. Foram preparadas suspensões com 60% vol. de fase polimérica (polissiloxanos e metil-trietoxi-silano e 40% vol. de carga (Si e Al2O3, com diferentes concentrações dos polímeros e das cargas. As amostras na forma de substratos foram pirolisadas em atmosfera de nitrogênio a 1400 °C/2 h e 1500 °C/2 h, sendo convertidas em materiais cerâmicos no sistema Si-Al-O-N-C. O processo de pirólise foi caracterizado até a temperatura de 1000 ºC por análise termogravimétrica. As cerâmicas foram caracterizadas quanto às fases formadas, microestrutura, massa específica aparente e condutividade térmica. Os substratos cerâmicos apresentaram porosidade relativamente alta (entre 12 e 22% e baixa condutividade térmica (entre 3 e 8 W/m.K, sendo constituídos por fases cristalinas de beta-SiC, Si2ON2, O'-SiAlON, Al2O3, mulita e fase amorfa de SiOC; o Si foi observado nas amostras pirolisadas a 1400 ºC.The tape casting technique has been widely used to prepare ceramic tapes for different applications: ceramic substrates and multilayer planar structures for integrated circuits and capacitors, solid electrolytes for fuel cells and sensors, piezoelectric ceramics for actuators and transducers, membrane systems for micro-filtration, structural composites and

  4. Determinação simultânea dos teores de cinza e proteína em farinha de trigo empregando NIRR-PLS e DRIFT-PLS Simultaneous determination of ash content and protein in wheat flour using infrared reflection techniques and partial least-squares regression (PLS

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    Marco Flôres Ferrão

    2004-09-01

    Full Text Available As técnicas de espectroscopia por reflexão no infravermelho próximo (NIRRS e por reflexão difusa no infravermelho médio com transformada de Fourier (DRIFTS foram empregadas com o método de regressão multivariado por mínimos quadrados parciais (PLS para a determinação simultânea dos teores de proteína e cinza em amostras de farinha de trigo da variedade Triticum aestivum L. Foram coletados espectros no infravermelho em duplicata de 100 amostras, empregando-se acessórios de reflexão difusa. Os teores de proteína (8,85-13,23% e cinza (0,330-1,287%, empregados como referência, foram determinados pelo método Kjeldhal e método gravimétrico, respectivamente. Os dados espectrais foram utilizados no formato log(1/R, bem como suas derivadas de primeira e segunda ordem, sendo pré-processados usando-se os dados centrados na média (MC ou escalados pela variância (VS ou ambos. Cinqüenta e cinco amostras foram usadas para calibração e 45 para validação dos modelos, adotando-se como critério de construção os valores mínimos do erro padrão de calibração (SEC e do erro padrão de validação (SEV. Estes valores foram inferiores a 0,33% para proteína e a 0,07% para cinza. Os métodos desenvolvidos apresentam como vantagens a não agressão ao ambiente, bem como permitem uma determinação direta, simultânea, rápida e não destrutiva dos teores de proteína e cinza em amostras de farinha de trigo.Partial Least Square (PLS multivariate calibration associated to Near Infrared Reflection Spectroscopy (NIRRS or Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS were used to establish methods for simultaneous determination of protein and ash content on commercial wheat flour samples of Triticum aestivum L. Duplicate spectra of 100 samples with protein content between 8.85-13.23% (Kjeldahl method and ash content between 0.330-1.287% (gravimetric method were employed to build calibration methods. The spectra were used

  5. Desenvolvimento de uma fase extratora com polímeros de impressão molecular para extração em fase sólida de Venlafaxina, O-desmetilvenlafaxina e N-desmetilvenlafaxina em amostras de plasmas e análises por cromatografia líquida de ultra eficiência acoplada à espectometria de massas em tandem (UPLC-MS/MS).

    OpenAIRE

    2015-01-01

    A venlafaxina (VEN), em razão de sua eficácia e brandos efeitos adversos, tem sido um dos antidepressivos mais prescritos no tratamento da depressão e ansiedade. Neste trabalho, um método analítico empregando as técnicas MISPE miniaturizada e cromatografia líquida acoplada à espectrometria de massas em Tandem, foi utilizado para a determinação de VEN e seus principais metabólitos em amostras de plasma para fins de monitorização terapêutica. A fase MIP foi sintetizada via polimerização radical...

  6. Preparo e avaliação do hidróxido duplo lamelar MgZnAl-Fe calcinado no processo de adsorção – fotodegradação do corante alaranjado de metila

    OpenAIRE

    Sousa, Paloma Viana Ferreira de

    2015-01-01

    Neste trabalho foi preparado o HDL magnético calcinado MgZnAl-Fe e caracterizado por Espectroscopia no Infravermelho (IV), Difratometria de Raios- X (DRX), Microscopia Eletrônica de Varredura (MEV), Espectrometria de Absorção Atômica e Reflectância Difusa. O desempenho fotocatalítico do MgZnAl-Fe foi avaliado utilizando o corante alaranjado de metila (corante do tipo azo) como composto modelo. Estudos fotocatalíticos com o MgZnAl-Fe foram feitos empregando-se uma concentração inicial de 100 m...

  7. Determination of fluconazole in serum and amniotic fluid of rats by gas-chromatography/mass spectometry (GC/MS Determinação de fluconazol em soro e líquido amniótico de ratas por cromatografia a gas/espectrometria de massas (CG/EM

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    Dione Marçal Lima

    2005-06-01

    Full Text Available Rats treated with oral dose of 100 mg/kg of fluconazole during pregnancy had their serum and amniotic fluid quantified for this drug using a GC/MS method. Fluconazole was extracted with ethyl acetate from samples and analysed by a GC-MS Shimadzu QP5050A system using a CBP-5 fused silica capillary column. Tioconazole was used as internal standard. Calibration curve was linear within the range 10.0 - 300.0 µg/mL. The limit of quantification was 0.1 µg/mL and no interference was observed in the blank serum and amniotic liquid. The mean concentrations of the drug in the serum and amniotic fluid were 206.01 ± 105.25 µg/mL and 125.34 ± 65.24 mug/mL, respectively. This procedure showed to be sensitive and efficient enough for the use in teratogenic studies of fluconazole and other azole drugs.Soro e líquido amniótico de ratas tratadas com fluconazol (dose oral de 100 mg/kg durante a prenhez foram quantificados para este fármaco usando cromatografia gasosa acoplada à espectroscopia de massas (CG/EM. O fluconazol foi extraído das amostras com acetato de etila e analisado empregando-se um cromatógrafo CG/EM Shimadzu QP5050A com coluna capilar de sílica fundida CBP-5. O tioconazol foi utilizado como padrão interno. A curva padrão foi linear no intervalo das concentrações de 10,0 a 300,0 µg/mL. O limite de quantificação foi de 0,1 µg/mL e não foi observada interferência no branco de soro e líquido amniótico. As concentrações médias do fármaco no soro e líquido amniótico foram 206,01 ± 105,25 µg/mL e 125,34 ± 65,24 µg/mL, respectivamente. Este procedimento mostrou-se sensível e eficiente para ser usado em estudos de teratogenicidade do fluconazol e outros azóis.

  8. (E-2-Nonenal determination in brazilian beers using headspace solid-phase microextraction and gas chromatographic coupled mass spectrometry (HS-SPME-GC-MS Determinação de (E-2-nonenal em cervejas brasileiras utilizando microextração em fase sólida do headspace e cromatografia gasosa acoplada a espectrometria de massas

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    Rodrigo Scherer

    2010-05-01

    Full Text Available (E-2-nonenal is considered an important off-flavor of beer, related to the flavor of beer staling. In this study, a new method for determination of (E-2-nonenal in beer using headspace solid-phase microextraction and gas chromatographic coupled mass spectrometry (HS-SPME-GC-MS was developed and applied in Brazilian beer samples. The extractions were carried out in CAR-PDMS (carboxen-polydimethylsiloxane fiber and the best results were found with 15 minutes of equilibrium and 90 minutes of extraction at 50 °C. The method was linear in the range from 0.02 to 4.0 μg.L-1 with correlation coefficient of 0.9994. The limits of detection and quantification were 0.01 and 0.02 μg.L-1, respectively. 96.5% of recovery and 4% precision (RSD were obtained in the fortification of beer samples with 2.0 μg.L-1 of (E-2-nonenal. The developed method proved to be simple, efficient and highly sensitive to the determination of this analyte being easily applied in the quality control of the brewery. (E-2-nonenal was found in all beer samples analyzed with levels between 0.17 and 0.42 μg.L-1.O (E-2-nonenal é considerado um importante off-flavor da cerveja, sendo relacionado ao sabor de cerveja envelhecida. Neste estudo, um novo método para determinação de (E-2-nonenal em cerveja usando microextração em fase sólida do headspace e cromatografia a gás acoplada à espectrometria de massa (HS-SPME-GC-MS foi desenvolvido e aplicado em amostras de cerveja brasileira. As extrações foram realizadas utilizando a fibra CAR/PDMS (carboxen/polidimetilsiloxano, com 15 minutos de tempo de equilíbrio e 90 minutos de exposição da fibra a 50 °C. O método foi linear na faixa de 0,02 e 4,0 μg.L-1, com coeficiente de correlação de 0,9994. Os limites de detecção e quantificação foram 0,01 e 0,02 μg.L-1, respectivamente. Foram obtidos 96,5% de recuperação e 4% de variação entre replicatas de amostras de cerveja fortificadas com 2,0 μg.L-1 de (E-2-nonenal. O m

  9. Quantificação laboratorial de cobre sérico por espectrofotometria Vis comparável à espectrometria de absorção atômica com chama Laboratorial quantification of serum copper by Vis spectrophotometry in comparison to flame atomic absorption spectrometry

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    Angela Maria Moro

    2007-08-01

    Full Text Available INTRODUÇÃO: O cobre é um nutriente essencial para os humanos, e a manutenção dos seus níveis é importante, uma vez que seu metabolismo está envolvido com estresse oxidativo e patologias, como a Doença de Wilson. Neste trabalho, um método de espectrofotometria visível (espectrofotometria Vis foi validado, aplicado em indivíduos jovens e comparado com espectrometria de absorção atômica com chama (EAA-chama. MÉTODOS: Concentrações séricas de cobre foram medidas por EAA-chama e por espectrofotometria Vis, através da reação de cobre com batocuproína, l = 484 nm. Curvas analíticas em solução aquosa e com adição de padrão foram efetuadas para verificar linearidade, recuperação e precisão do método espectrofotométrico. Amostras de sangue de 12 indivíduos (média de idade 22 anos foram analisadas por ambos os métodos e comparadas entre si. Os resultados foram expressos em média ± desvio-padrão. RESULTADOS: As curvas com adição de padrão e aquosa (n = 5 apresentaram coeficientes de regressão superiores a 0,99 e de variação inter e intradia inferiores a 15%. Os valores de cobre sérico encontrados para o método espectrofotométrico foram 1,17 ± 0,39 e 0,73 ± 0,14 mg/l para mulheres e homens, respectivamente. Para EAA-chama foram encontrados 1,13 ± 0,43 e 0,59 ± 0,13 mg/l para mulheres e homens, respectivamente. Os resultados mostraram correlação de Pearson significativa (r = 0,946; p BACKGROUND: Copper is an essential nutrient for humans and maintenance of its adequate levels is important, since its metabolism is involved with oxidative stress and patolologies, such as Wilson's disease. In this work, a visible spectrophotometric method was validated, applied in young subjects and compared to flame atomic absorption spectrometry (FAAS in serum copper levels determination. METHODS: Serum copper concentrations were measured by FAAS and by spectrophotometry, through copper reaction with bathocuproine, l = 484

  10. Desenvolvimento de metodologia para determinação de 4-cloroanilina em frangos por cromatografia gasosa - espectrometria de massas: análise em tecidos tratados com digluconato de clorhexidina após o processamento térmico Methodology for 4-chloroaniline determination in poultry by GC-MS: analisys in chlorhexidine digluconate treated tissues after termical processing

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    Eduardo Vicente

    2003-12-01

    Full Text Available A degradação do antimicrobiano digluconato de clorhexidina (DGCH durante armazenamento ou processamento térmico pode formar a 4-cloroanilina (CA, um composto potencialmente carcinogênico. Conseqüentemente, o uso deste sanitizante para descontaminação de carcaças de frangos representa uma fonte de risco para o consumidor, devendo ser avaliada a presença da CA no produto tratado. Um método foi desenvolvido para determinação de resíduos de CA em tecidos de frangos. Após a extração com diclorometano, foi feita a limpeza do extrato em cartucho C18 e quantificação por cromatografia gasosa-espectrometria de massas (CG-EM, sem derivação. A recuperação média (89,2% - CV 9,9%. e o limite de detecção (1,8ng/g foram considerados satisfatórios para os propósitos do estudo. Em amostras tratadas com DGCH e não submetidas a processamento térmico, a quantidade de CA detectada foi relativamente baixa, e provavelmente se originou da solução de tratamento. A fritura e a cocção em forno convencional resultaram em níveis elevados de CA, enquanto que a cocção em panela de pressão não alterou os níveis de CA presentes na amostra crua. Em vista destes resultados e, considerando-se o potencial tóxico da CA, recomenda-se que estes dados sejam levados em consideração quando avaliada a utilização de DGCH como sanitizante de carcaças em abatedouros de aves.The degradation of the antimicrobial agent chlorhexidine digluconate (CHDG during storage or thermal process originates 4-chloroaniline (CA, a compound which is potentially carcinogenic. As the use of this sanitizing agent to decontaminate poultry carcasses in processing plants may represent a risk to the consumers, it is important to search for the presence of CA residues in the treated products. A method was developed to quantify CA in poultry tissues. After dichloromethane extraction, the extract was cleaned on a C18 cartridge and the quantitation was performed, without

  11. Estudo comparativo da resistência adesiva da interface resina/braquete, sob esforços de cisalhamento, empregando três resinas compostas e três tipos de tratamento na base do braquete Comparative study of the shear bond strength of the resin/bracket interface, using three different resin composites and three different treatments in the base of the bracket

    Directory of Open Access Journals (Sweden)

    Adriano Lia Mondelli

    2007-06-01

    Full Text Available OBJETIVO: considerando que, até o momento, a união braquete/resina é conseguida mecânica e quimicamente, esse estudo propôs avaliar: 1 a eficiência da metodologia empregada para avaliação da força de união da interface resina/braquete; 2 a resistência adesiva da interface resina/braquete sob esforços de cisalhamento, empregando três marcas comerciais de resina composta (Concise ortodôntico, Transbond-XT e Filtek-Z-250; 3 o efeito, nesta resistência adesiva, do jateamento com óxido de alumínio, aplicado na base do braquete metálico, associado ou não ao sistema adesivo resinoso dentário. METODOLOGIA: para avaliar a união adesiva, especificamente na interface resina/braquete, empregou-se uma máquina universal de ensaios e o teste preconizado foi o de cisalhamento. RESULTADOS E CONCLUSÕES: após análise estatística (análise de Variância e, posteriormente, teste de Tukey e discussão dos resultados, conclui-se que: a ocorrência de 12,5% de fraturas coesivas pode ser considerada mínima, indicando que a metodologia empregada pode ser considerada confiável para avaliar especificamente a força de união da interface resina/braquete; em relação aos tipos de materiais empregados, sem nenhum tratamento prévio, as resinas compostas Concise ortodôntico, Transbond-XT e Filtek-Z-250 apresentaram valores similares de resistência adesiva sob esforços de cisalhamento; os tratamentos que incluíam a aplicação do adesivo específico, com ou sem jateamento com óxido de alumínio na base do braquete, foram mais efetivos para a resina composta Concise ortodôntico, quando comparados ao seu grupo controle; os tratamentos de jateamento com óxido de alumínio, associado ou não ao adesivo específico na base do braquete, foram mais efetivos estatisticamente para a resina composta Transbond-XT, quando comparados ao seu grupo controle; para a resina composta Filtek-Z-250, quando utilizado o adesivo Single Bond na base do braquete

  12. Espectrometria de Massas em Geologia Isotópica

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    Kei Sato

    2002-12-01

    Full Text Available The present paper discusses the main types of mass spectrometers available in 2002 (TIMS, ICP-MS, SIMS andelectron impact-MS with application to isotope geology and especially to geochronology. Brief comments on theprinciples of operation of the main components, ionization sources, mass analyzers and ion detectors are made. Finally,the performance of the different types of spectrometers is compared.

  13. Espectrometria de Massas em Geologia Isotópica

    OpenAIRE

    Kei Sato; Koji Kawashita

    2002-01-01

    The present paper discusses the main types of mass spectrometers available in 2002 (TIMS, ICP-MS, SIMS andelectron impact-MS) with application to isotope geology and especially to geochronology. Brief comments on theprinciples of operation of the main components, ionization sources, mass analyzers and ion detectors are made. Finally,the performance of the different types of spectrometers is compared.

  14. Digital filters in spectrometry; Filtros digitales en espectrometria

    Energy Technology Data Exchange (ETDEWEB)

    Barron B, J. I.; Hernandez D, V. M.; Vega C, H. R., E-mail: israel_176@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico)

    2013-10-15

    In this work is presented the development and application of the digital signal processing for different multichannel analysis spectra. The use of the smoothing classic methods in applications of signal processing is illustrated by a filters discussion; autoregressive, mobile average and the ARMA filters. Generally, simple routines of lineal smoothing do not provide appropriate smoothing of the data that show the local ruggedness as the strong discontinuities; however the indicated development algorithms have been enough to leave adapting to this task. Four algorithms were proven: autoregressive, mobile average, ARMA and binomial methods for 5, 7, and 9 of data, everything in the domain of the time and programmed in Mat lab. (Author)

  15. Optimization and validation of a methodology to determine total arsenic, As(III and As(V, in water samples, through graphite furnace atomic absorption spectrometry Otimização e validação de metodologia de determinação de arsênio total, As(III e As(V, em amostras de água por espectrometria de absorção atômica com forno de grafite

    Directory of Open Access Journals (Sweden)

    Lisia Maria Gobbo Santos

    2009-03-01

    Full Text Available The Graphite furnace atomic absorption spectrometry (GF AAS was the technique chosen by the inorganic contamination laboratory (INCQ/ FIOCRUZ to be validated and applied in routine analysis for arsenic detection and quantification. The selectivity, linearity, sensibility, detection, and quantification limits besides accuracy and precision parameters were studied and optimized under Stabilized Temperature Platform Furnace (STPF conditions. The limit of detection obtained was 0.13 µg.L-1 and the limit of quantification was 1.04 µg.L-1, with an average precision, for total arsenic, less than 15% and an accuracy of 96%. To quantify the chemical species As(III and As(V, an ion-exchange resin (Dowex 1X8, Cl- form was used and the physical-chemical parameters were optimized resulting in a recuperation of 98% of As(III and of 90% of As(V. The method was applied to groundwater, mineral water, and hemodialysis purified water samples. All results obtained were lower than the maximum limit values established by the legal Brazilian regulations, in effect, 50, 10, and 5 µg.L-1 para As total, As(III e As(V, respectively. All results were statistically evaluated.A técnica de espectrometria de absorção atômica com forno de grafite (GF AAS foi a técnica escolhida pelo laboratório de contaminantes inorgânicos do Instituto Nacional de Controle de Qualidade em Saúde (INCQS/FIOCRUZ para ser validada e aplicada em análises de rotina para detecção e quantificação de arsênio. Os parâmetros de validação seletividade, linearidade, sensibilidade, limite de detecção e quantificação, exatidão e precisão foram estudados e otimizados usando as condições STPF (Stabilized Temperature Platform Furnace. Os resultados encontrados apresentaram limites de detecção 0,13 µg.L-1 e quantificação de 1,04 µg.L-1, uma precisão média para arsênio total inferior a 15% e uma exatidão de 96%. Para quantificar as espécies químicas As(III e As(V, utilizamos

  16. A politica estadunidense de desgermanizacao do sistema de transporte aereo brasileiro: o caso da Condor

    National Research Council Canada - National Science Library

    Quintaneiro, Tania

    2009-01-01

    Analise e avaliacao da politica dos Estados Unidos de extincao das atividades da empresa de transporte aereo Condor, por meio de sua inclusao na Lista Negra, do corte no fornecimento de combustivel...

  17. Individual internal monitoring of workers of Fabrica de Combustivel Nuclear - FCN; Monitoracao individual interna de trabalhadores da Fabrica de Combustivel Nuclear - FCN

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marcelo X. [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil). Fabrica de Combustivel Nuclear]. E-mail: marcelo@inb.gov.br; Melo, Dunstana R.; Cunha, Kenia D. da; Juliao, Ligia Q.C.; Santos, Maristela S.; Fernandes, Paulo C.; Lucena, E.A.; Dantas, Ana L.; Dantas, Bernardo M.; Godoy, Maria L. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)]. E-mail: dunstana@ird.gov.br

    2005-07-01

    In nuclear fuel fabrication facilities, workers are exposed to different compounds of enriched uranium. Due to the high cost of the individual monitoring programme for internal dose assessment in the routine monitoring programmes, usually only one type of measurement is assigned. In complex situations like the one described in this paper, where several parameters can compromise the accuracy of the bioassay interpretation it is need to have a combination of techniques to evaluate the internal dose. According to ICRP 78 (1997), the general order of preference in terms of accuracy of interpretation is: body activity measurement, excreta analysis and personal air sampling. A group of fifteen workers from controlled area of the fuel fabrication facility was selected to evaluate the internal dose using all different available techniques during a certain period. The workers were monitored for determination of uranium content in the daily urinary excretion, faecal excretion, chest counting and personal air sampling (PAS). The results have shown that at least two types of sensitivity techniques must be used, since there are some sources of uncertainties on the bioassay interpretation, like mixture of uranium compounds intake and different routes of intake. The combination of urine and faeces analysis has shown be the more appropriate methodology for assessing internal dose in this situation. (author)

  18. Qualidade de vida entre adolescentes: estudo seccional empregando o SF-12

    Directory of Open Access Journals (Sweden)

    Marise Fagundes Silveira

    2013-07-01

    Full Text Available A adolescência é um período em que comportamentos potencialmente lesivos ao estado de saúde podem ser iniciados. A avaliação da qualidade de vida nesse contingente torna-se útil para a identificação de grupos em maior risco para comprometimento do bem estar geral. O presente estudo objetivou avaliar a qualidade de vida e fatores associados em uma amostra de 754 adolescentes, com faixa etária de 15 a 19 anos. Para a mensuração da qualidade de vida foi utilizada a versão na língua portuguesa do questionário 12-Item Short-Form Health Survey (SF 12. Os resultados apontaram níveis satisfatórios de qualidade de vida, sendo estes maiores com a prática frequente de atividade física e a ausência de condições como atividades trabalhistas e consumo de tabaco e bebida alcóolica. O sexo feminino foi correlacionado a menores escores em aspectos mentais da qualidade de vida.

  19. Receptor GPS em software em tempo real empregando processador de sinais digitais.

    OpenAIRE

    Fabrício de Araujo Carvalho

    2008-01-01

    O trabalho apresenta a etapa de correlação em software de um receptor GPS de uso civil. O software do correlator tem como função extrair, em tempo real, os dados de navegação contidos no sinal GPS (CDMA), os quais são necessários para a determinação da posição dos satélites. Este trabalho apresenta também uma revisão das características e da estrutura do sinal GPS, para permite uma melhor compreensão do funcionamento das arquiteturas dos correlatores descritos na literatura e também, desenvol...

  20. Modelagem de desempenho de servidores Web empregando a teoria Network Calculus /

    OpenAIRE

    2005-01-01

    Orientadora: Cristina Duarte Murta Dissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Cięncias Exatas, Programa de Pós-Graduaçăo em Informática. Defesa: Curitiba, 2005 Inclui bibliografia

  1. BIODISPONIBILIDADE DE METAIS TÓXICOS EM SEDIMENTOS DO RIO SUBAÉ, BAHIA, BRASIL

    Directory of Open Access Journals (Sweden)

    Jucelino Balbino da Silva Júnior

    2016-12-01

    Full Text Available Este trabalho avaliou a biodisponibilidade dos metais Pb, Cd, Zn, Cu e Ni, empregando a técnica dos sulfetos voláteis em ácido (AVS e metais simultaneamente extraídos (SEM, contemplando período chuvoso e de estiagem. As amostras de sedimento foram coletadas em 10 (dez estações ao longo da bacia do rio Subaé, desde a sua nascente até a foz na Baía de Todos os Santos (BTS. Os metais liberados durante a extração foram analisados usando espectrometria de fluorescência de raios-X (TXRF e espectrometria de absorção atômica com otimização eletrotérmica em forno de grafite (GFAAS, e os sulfetos voláteis foram quantificados utilizando potenciometria com eletrodo de íon seletivo (IES. A partir dos resultados obtidos, pode-se concluir, em função dos valores encontrados para os sulfetos e da matéria orgânica, que as concentrações de metais apresentaram valores que caracterizam a possibilidade de efeitos biológicos adversos para a biota nas regiões de baixa salinidade, em ambos os períodos.

  2. Characterization and classification of pequi trees (Caryocar brasiliense Camb. based on the profile of volatile constituents using headspace solid-phase microextraction - gas chromatography - mass spectrometry and multivariate analysis Caracterização e classificação de pequizeiros (Caryocar brasiliense Camb. baseadas no perfil de constituintes voláteis usando microextração em fase sólida no modo headspace - cromatografia a gás - espectrometria de massas e análise multivariada

    Directory of Open Access Journals (Sweden)

    Renata França Cassimiro Belo

    2013-02-01

    Full Text Available In order to determine the variability of pequi tree (Caryocar brasiliense Camb. populations, volatile compounds from fruits of eighteen trees representing five populations were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. Seventy-seven compounds were identified, including esters, hydrocarbons, terpenoids, ketones, lactones, and alcohols. Several compounds had not been previously reported in the pequi fruit. The amount of total volatile compounds and the individual compound contents varied between plants. The volatile profile enabled the differentiation of all of the eighteen plants, indicating that there is a characteristic profile in terms of their origin. The use of Principal Component Analysis and Cluster Analysis enabled the establishment of markers (dendrolasin, ethyl octanoate, ethyl 2-octenoate and β-cis-ocimene that discriminated among the pequi trees. According to the Cluster Analysis, the plants were classified into three main clusters, and four other plants showed a tendency to isolation. The results from multivariate analysis did not always group plants from the same population together, indicating that there is greater variability within the populations than between pequi tree populations.A fim de determinar a variabilidade de populações de pequizeiro (Caryocar brasiliense Camb., compostos voláteis de frutos de dezoito árvores representando cinco populações foram extraídos por microextração em fase sólida no modo headspace e analisados por cromatografia a gás acoplada à espectrometria de massas. Setenta e sete compostos foram identificados, incluindo ésteres, hidrocarbonetos, terpenoides, cetonas, lactonas e álcoois. Vários compostos não haviam sido encontrados anteriormente no fruto. A quantidade total e a composição de voláteis variaram entre as plantas. O perfil volátil permitiu a diferenciação de todas as dezoito plantas, indicando que há um

  3. CUANTIFICACIÓN DE MERCURIO EN TERMOFORMADOS Y PELÍCULAS FLEXIBLES BIODEGRADABLES ELABORADAS A PARTIR DE YUCA (Manihot esculenta Crantz POR ESPECTROMETRÍA DE ABSORCIÓN ATÓMICA QUANTIFICAÇÃO DE MERCÚRIO EM TERMOFORMADOS E PELÍCULAS FLEXÍVEIS BIODEGRADÁVEIS ELABORADAS A PARTIR DE MANDIOCA (Manihot esculenta Crantz POR ESPECTROMETRIA DE ABSORÇÃO ATÔMICA QUANTIFICATION OF MERCURY IN THERMOFORMED AND FLEXIBLE FILMS BIODEGRADABLE MADE FROM CASSAVA (Manihot esculenta Crantz BY ATOMIC ABSORPTION SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    ROBERTO JULIÁN DEL CASTILLO R

    2012-12-01

    Full Text Available Se cuantificó el contenido de mercurio en siete muestras de termoformados y seis de películas flexibles biodegradables, por espectrometría de absorción atómica con vapor frío; previamente a ésta cuantificación, se realizó la implementación y estandarización del método analítico, en el cual se determinaron los parámetros de calidad estadística (Límite de detección y de cuantificación, intérvalo lineal, sensibilidad de calibración, precisión y exactitud, que establecieron el rendimiento del método. Los termoformados se digestaron con una mezcla HNO3:HClO4, relación 3:1, durante 3 horas a 70°C y las películas flexibles por 45 minutos a 50°C. Las muestras se cuantificaron por el método de curva de calibración a 253,7 nm, obteniéndose concentraciones de mercurio en el rango de no detectable a 60 µg/L en termoformados y de no detectable a 6 µg/L en las películas flexibles.Quantificamos o teor de mercúrio em sete amostras de termoformados e seis películas flexíveis biodegradáveis por espectrometria de absorção atômica com vapor frio; antes de esta medida, realizamos a implementação e padronização do método analítico, na qual os parâmetros de qualidade estatística foram determinados (limite de detecção e quantificação, faixa linear, sensibilidade de calibração, precisão e exatidão, que estabeleceu o desempenho do método. O digestor é termoformado com uma mistura HNO3:HClO4, uma proporção de 3:1 durante 3 horas a 70°C e filmes flexíveis por 45 min a 50°C. As amostras foram quantificadas pelo método da curva de calibração 253,7 nm, resultando em concentrações de mercúrio na faixa de não detectável a 60 mg/L em termoformados e não detectável a 6mg/L em filmes flexíveis.The mercury content of seven thermoformed and six biodegradable flexible films samples were evaluated by atomic absorption spectrometry with cold vapor; before the experiments, the statistical quality parameters were

  4. Membranes for hydrogen and fuel cell technology; Membranas para celula combustivel e separacao de hidrogenio

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Suzana Pereira [GKSS-Forschungszentrum, Geesthacht (Germany)]. E-mail: nunes@gkss.de

    2005-07-01

    Membranes for fuel cell were prepared using as polymer matrix sulfonated polyether ketones. New sulfonated copolymers (poly oxazoles, poly imides and poly ketones) were synthesized. Nano composites using zirconium oxide and phosphates, as well as modified silicates were obtained aiming the application on direct methanol fuel cell (DMFC). The performances of membranes containing fillers with different aspects (spherical, layers, tubular, networks) and surface modification (hydroxy, imidazole, acid oligomers) were compared. The effect of surface modification was much more pronounced than that of the aspect. A good balance of proton conductivity and methanol permeability was obtained with silicates modified with imidazole groups. Good performance in DMFC were obtained with membranes containing zirconium phosphate. Acid oligomers also led to particularly high conductivity values above 100 deg C. Polyimide membranes with H{sub 2}/CH{sub 4} larger than 100 were obtained. (author )

  5. Bioethanol fuel: an opportunity for Brazil; Bioetanol combustivel: uma oportunidade para o Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cerqueira Leite, Rogerio Cezar de; Sobral Junior, Manoel; Leal, Manoel Regis Lima Verde; Cortez, Luis Augusto Barbosa [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico

    2009-10-15

    This book is divided in 10 chapters approaching the following subjects: Bio ethanol perspectives in the market of liquid fuels for light vehicles, description of the production process - agricultural phase and industrial phase, potential areas for the expansion of the sugar cane production, existent infrastructure and improvement projects, technological scenarios construction on the production of bio ethanol in Brazil, Evaluation of social and economical impacts related to the large scale production of bio ethanol in Brazil, sustainability, regulatory mark, and identification of the necessities of R and D and alternative suggestions for his financing.

  6. Development of solid oxide fuel cells; Desenvolvimento de celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Alencar, Marcelo Goncalves F. de; Amaral, Alexandre Alves do; Benedicto, Joao Paulo Santos; Silva, Marcos A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica

    2006-07-01

    Fuel cells allow the energy production without the thermodynamic restriction of the conversion of heat into work. Among their various types, the solid oxide fuel cells (SOFC), operating at high temperatures, allow the methane conversion into electricity directly on the anode. The main element of the SOFC is the structure A/E/C: anode/electrolyte/cathode, all sintered at high temperature as resistant ceramic materials. Dense electrolyte (YSZ: zirconia stabilized for Yttria) separates the anode (Ni+Co/YSZ: cobalt promoted nickel, supported on YSZ) and cathode (LSM: strontium-doped lanthanum manganite), both with porosity obtained by graphite addition. To obtain suitable A/E/C pellets, the layer sintering with appropriate mechanical and textural characteristics is essential, requiring excellent electric junctions between them. The cell performance has been evaluated between 850 and 950 degree C, using hydrogen or methane fuel; the tension and current for different resistance values in the electrical circuit have been measured. The cobalt addition to the cell anode significantly increased its activity for the reform reaction. The beneficial effect was probably due to the easier nickel reduction in cobalt presence. This work had the objectives of developing and evaluating electro-catalysts, as well as the solid oxide fuel cells using these catalysts as anode. Five SOFC models (SOFC 1 to SOFC 5) are described; all of them were developed aiming at improving the preparation of the anode/electrolyte/cathode structure (A/E/C). (author)

  7. Laboratory of High resolution gamma spectrometry; Laboratorio de espectrometria gamma de alta resolucion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B

    1992-01-15

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  8. Neutron spectrometry and dosimetry using NSDAAN; Espectrometria y dosimetria de neutrones usando NSDAAN

    Energy Technology Data Exchange (ETDEWEB)

    Martinez B, M. R.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Ortiz R, J. M. [Departamento de Electrotecnia y Electronica, Escuela Politecnica Superior, Av. Menendez Pidal s/n, 14004 Cordoba (Spain)], e-mail: mrosariomb@yahoo.com.mx

    2009-10-15

    The reconstruction of neutron spectra from count rates of a Bonner spheres spectrometric system is performed using various methods such as Monte Carlo methods, the parameterization and iterative methods. The weight of the Bonner spheres spectrometric system, the procedure for the reconstruction of the spectra, the need of an experienced user, the high consumer of time, the need of use a reconstruction code as the BUNKI, SAND, among others, and the resolution of the spectrum are some problems that this system presents. This has motivated the development of complementary procedures such as maximum entropy, genetic algorithms and artificial neural networks. In previous work, has reported a new method called robust design methodology of artificial neural networks, to construct various network topologies capable of solving the problems of neutron spectrometry and dosimetry, however, due to the newness of this technology, be noted that there are not tools to end-user that allow test and validate the designed networks. This paper presents a software for the neutron spectrometry and dosimetry, designed from the information extracted of an artificial neural network designed by robust design methodology of artificial neural networks. This tool has the following characteristics: was designed in a user graphical interface easy to use, requires not knowledge of neural networks or neutron spectrometry by the user; execution speed of the application; unlike the deconvolution codes are not required to select an initial spectrum for the spectrum reconstruction; as an additional element to this tool, besides the spectrum, the calculation is performed simultaneous to H(10), E, H{sub p},{sub s}(10,{theta}) from just counting rates from a Bonner spheres spectrometric system. (author)

  9. Espectrometria de massa de razões isotópicas

    OpenAIRE

    Ferreira, Ana Isabel Amaral Janeiro Viegas, 1961-

    2008-01-01

    Tese de doutoramento em Química (Química Analítica), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008 As técnicas isotópicas são metodologias muito poderosas usadas na detecção da adulteração de géneros alimentícios. O acoplamento de cromatógrafos em fase gasosa (GC) a um espectrómetro de massa de razões isotópicas (IRMS), com uma interface de combustão (GC/C/IRMS) para determinação das razões isotópicas tais como 13C/12C e15N/14N é relativamente recente e aprese...

  10. Gamma spectrometry of irradiated fuel plates; Espectrometria gama em elementos combustiveis tipo placa irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1997-10-01

    This work describes the fundamental aspects of a method which uses gamma-ray spectroscopy in order to perform non-destructive burnup measurements in irradiated MTR fuel elements. Experiments based on such method will be conducted at the storage pool area of the IEA-R1 research reactor. Some preliminary results are presented. (author). 10 refs., 5 figs., 1 tab.

  11. Eletroforese capilar acoplada à espectrometria de massas (CE-MS): vinte anos de desenvolvimento

    OpenAIRE

    Assunção, Nilson Antonio [UNIFESP; Bechara, Etelvino José Henriques [UNIFESP; Simionato,Ana Valéria Colnaghi; Tavares, Marina Franco Maggi; Carrilho, Emanuel

    2008-01-01

    CE-MS has been increasingly used for analysis of a vast array of compounds. This article reviews the different electrophoretic modes, interfaces and mass analyzers that are commonly used in the CE-MS coupling, as well as the technique advantages and performance characteristics. A large compilation of CE-MS applications is also presented. Therefore, this review is both a guide for beginners and a collection of key references for people who are familiar to the technique. Furthermore, this is th...

  12. Novas aplicações da espectrometria de massas em química forense

    OpenAIRE

    Wanderson Romão

    2010-01-01

    Resumo: Embora seja um tema que desperte bastante interesse perante a sociedade científica, a aplicação da química no campo da criminalística ainda constitui uma nova linha de pesquisa no Brasil. Neste trabalho, o perfil químico de várias drogas de abuso (anfetaminas, piperazinas, cocaína e dietilamida do ácido lisérgico (LSD)), documentos e derivados de petróleo foram investigados. Para análise de drogas de abuso, a easy ambient sonic-spray ionization (EASI-MS) é uma poderosa ferramenta na c...

  13. Design and fabrication of shielding for gamma spectrometry; Diseno y fabricacion de blindaje para espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Mariano H, E

    1991-05-15

    To have a system of gamma spectrometry in the Radiological Mobile Unit No. 1 (UMOR-1) was designed and manufactured an armor-plating appropriate to this, to make analysis of radioactive samples in place in the event of a radiological emergency, besides being able to give support to the Management of Radiological Safety, and even to give service of sample analysis of other Institutions. (Author)

  14. Characterization of radioactive orphan sources by gamma spectrometry; Caracterizacion de fuentes huerfanas radiactivas por espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Cruz W, H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (PGRR/IPEN), Lima (Peru). Planta de Gestion de Residuos Radiactivos

    2013-07-01

    The sealed radioactive sources are widely applicable in industry. They must have a permanent control and must be registered with the Technical Office of the National Authority (OTAN). However, at times it has identified the presence of abandoned sealed sources unknown to the owner. These sources are called 'orphan sources'. Of course these sources represent a high potential risk because accidents can trigger dire consequences depending on your activity and chemical form in which it presents the radioisotope. This paper describes the process and the actions taken to characterize two orphan radioactive sources from the smelter a Aceros Arequipa. For characterization we used a gamma spectrometry system using a detector NaI(Tl) 3″ x 3″ with a multichannel analyzer Nucleus PCA-II. The radioisotope identified was cesium - 137 ({sup 137}Cs) in both cases. Fortunately, the sources maintained their integrity would otherwise have generated significant pollution considering the chemical form of the radioisotope and easy dispersion. (author)

  15. Neutron spectrometry with organic scintillation detector; Espectrometria de nuetrones con cristales de centelleo organicos

    Energy Technology Data Exchange (ETDEWEB)

    Butragueno Casdo, J. L.

    1972-07-01

    This work describes a fast neutron spectrometer using a stilbene crystal as head detector with pulse shape discrimination (P.S.D.) to reject gamma background. Tre experimental procedure involves the P.S.D., the measurements to calibrate the spectrometer and the corrections for several factors, mainly the non-linear response of the stilbene. Results of the measurements with the reaction D{sup 2}(d,n)He{sup 3}, and with an Am-Be neutron source are presented. It is also presented the measurement of the spectrum of the fast reactor CCRAl-1. (Author) 17 refs.

  16. Análise de decisão Multicritério: um caso empregando o Macbeth

    Directory of Open Access Journals (Sweden)

    André Andrade Longaray

    2010-05-01

    Full Text Available O presente artigo tem por objetivo descrever o emprego da metodologia MCDA-Construtivista no processo de apoio à decisão para auxiliar um decisor na compra de um imóvel para sua família. Para tanto, após a contextualização do cenário decisório, é demonstrada a forma pela qual foram determinadas as funções de valor para os critérios e subcritérios do modelo, por meio de julgamento semântico, usando o software MACBETH. As taxas de substituição do modelo, bem como a fórmula de agregação aditiva global, também são delineadas. Por fim, é feita a análise de sensibilidade de três alternativas de imóveis.

  17. Análise screening de vinhos empregando um analisador fluxo-batelada, espectroscopia UV-VIS e quimiometria

    OpenAIRE

    Jaqueline Azevedo Nascimento; Amália Geíza Gama Dionísio; Elaine Cristina Lima do Nascimento; Sueny Kêlia Barbosa Freitas; Mário César Ugulino de Araújo

    2010-01-01

    A simple, robust, versatile, high analytical frequency method was proposed to check if a sample of wine is within the range of standards set by the manufacturer, using the UV-VIS spectroscopy, multivariate analysis and a flow-batch analyzer. Two hundred and fifty-two samples of wines were analyzed. The results from the application of Hierachical Cluster Analysis (HCA) to the matrix of the data involving all samples show the formation of fifteen types of wine. A Soft Independent Modelling of C...

  18. Estudo de metabolismo in vitro do alcalóide Piplartina empregando microssomas hepático de ratos

    OpenAIRE

    2013-01-01

    O gênero Piper pertencente à família Piperaceae, encontra-se distribuído nas regiões tropicais e subtropicais do globo. Estudos químicos têm demonstrado diversidade de metabólitos secundários com atividade biológica. Os alcalóides são metabólitos característicos. A piplartina, (E)-1-(3-(3,4,5-trimetoxifenil)acriloil)-5,6- diidropiridin-2(1H)-ona, é um alcalóide encontrado em muitas espécies. Tem atividade citotóxica contra células de linhagem tumoral, ansiolítica, antidepressiva, antifúngica ...

  19. Tentativa de erradicação da himenolepíase em uma comunidade semifechada, empregando-se praziquantel

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Magalhães de Castro

    1985-02-01

    Full Text Available Duas semanas após o insucesso da terapêutica com mebendazol — 400 mg diários durante quatro dias consecutivos —, 101 indivíduos de uma comunidade semifechada, 50,5% infectados por Hymenolepis nana, em sua maioria crianças entre dois e seis anos de idade, foram tratados com praziquantel (* em duas doses orais de 20 a 25 mg/kg, administradas com dez dias de intervalo. O diagnóstico da himenolepíase, bem como os controles de cura parasitológica realizados nos 7.º, 14.°, 21°, 30.°, 60.° e 90.° dias depois da administração da segunda dose de praziquantel, basearam-se em exames de fezes pelo método quantitativo de KATO/KATZ. A tolerância ao medicamento foi excelente e a negativação dos exames ocorreu independentemente da intensidade do parasitismo. Nos 7.° e 14° dias pós-tratamento encontraram-se ovos de H. nana, respectivamente em nove e em dois pacientes, mas esses ovos apresentavam-se distorcidos. No controle do 21.° dia todos os resultados mostraram-se negativos, traduzindo um índice de cura de 100%. A partir do 30.° dia verificou-se em três crianças a eliminação de ovos normais do parasita. Tendo em vista serem essas as únicas que viviam em regime de semi-internação nessa comunidade e a positividade tardia dos exames, esses casos foram considerados como reinfecção. Conclui-se, pelos resultados alcançados, que o esquema posológico empregado, fundamentado nas investigações experimentais conduzidas por CAMPOS & col. (1983, é eficaz e seguro para o tratamento da himenolepíase, em especial, quando se pretende tentar erradicá-la numa comunidade fechada.

  20. Remoção do Corante Têxtil Turquesa de Remazol Empregando Aguapé (Eichhornia crassipes como Adsorvente

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Holanda

    2015-06-01

    Full Text Available In this work, the efficient removal of Remazol Turquoise textile dye onto water hyacinth (Eichhornia crassipes from aqueous solutions was investigated by batch method. The water hyacinth was collected, washed, dried, crushed and treated with a 0,25 mol L-1 HNO3, at 50 °C and by 24 h. Parameters such as pHpzc, pH effect, contact time and temperature were considered. The kinetic and adsorption data were analyzed by using the Lagergren, Ho, Zeldowitsch (Elovich, and Weber-Morris models, and Langmuir, Freundlich, Tempkin, Redlich-Peterson, Sips and multilayers isotherm models, respectively. The best fitting modeling were Ho (50 mg L-1, Elovich (1000 mg L-1 and Sips. The thermodynamic parameters (ΔHads, ΔSads and ΔGads and desorption tests showed that adsorption mechanism is dependent on several adsorbate/surface interactions. DOI: http://dx.doi.org/10.17807/orbital.v7i2.622

  1. Remoção de Carbofurano em Água Empregando Resíduos Agroindustriais como Adsorventes

    Directory of Open Access Journals (Sweden)

    Tiago dos Santos Estrela

    2016-02-01

    Full Text Available In this study aimed to evaluate the possibility of using industrial boiler ash and rice husk ash in removing the commercial pesticide (carbofuran in aqueous solution. These solids were collected in the Barreiras/BA, were heat treated and characterized by XRD and FT-IR. The adsorption experiments were performed in batch and the carbofuran removal was quantified using the spectrophotometry in the UV region. XRD data showed high silica content in boiler ash, which was reinforced by FT-IR analyses, showing the band FT-IR associated with presence of silica. In the FT-IR analysis of rice husk ash, this band relative to silica also were observed. The potential of adsorption of the ash industrial boiler and rice husk ash was verified obtaining significant results in the removal of carbofuran at low concentrations (2 mg/L, showing 100% of removal of pesticides from 720 min, used the ash industrial boiler, giving these materials a promising character as adsorbents. In the kinetic study of carbofuran adsorption, the mechanism of pseudo-second-order was better adjusted using the RHA as adsorbent, with a correlation coefficient (R2 of 0.997. The adsorption equilibrium was adjusted better to model of adsorption isotherm of Freundlich with a correlation coefficient of 0.999. DOI: http://dx.doi.org/10.17807/orbital.v1i1.716

  2. The reformation of ethanol and application to fuel cells; A reforma do etanol e sua aplicacao em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ennio Peres da; Camargo, Joao Carlos [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: lh2ennio@ifi.unicamp.br; joaoc@fem.unicamp.br; Carolino, Iaponira Rando [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Quimica]. e-mail: yaponira@hotmail.com

    2002-07-01

    This paper presents the perspectives for using of ethanol (EtOH) obtained from the sugar cane for electric power production, through a integrated system constituted by a hydrogen generator, by using the ethanol reforming associated to a fuel cell feed with the produced hydrogen. The paper also focuses the present re-structuration of the Brazilian electric sector identifying the possibility of implantation that system.

  3. Mineral spirits addition to automotive gasoline: fuel quality impacts; Adicao de aguarras a gasolina automotiva: impactos na qualidade do combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Selmo Queiroz; Teixeira, Leonardo Sena Gomes; Pontes, Luiz Antonio Magalhaes; Vitor Sobrinho, Eledir; Guimaraes, Paulo Roberto Britto; Vianna, Regina Ferreira [Universidade Salvador - UNIFACS, Salvador, BA (Brazil). Dept. de Engenharia e Arquitetura]. E-mail: leonardoteixeira@unifacs.br

    2003-07-01

    The unlawful addition of hydrocarbons such as mineral spirit, kerosene, thinner and diesel oil to gasoline has been often observed in Brazil lately. This not only results in undeserved market advantage, but may also cause serious damage to the consumer and to the environment, since it may change several physicochemical properties of the fuel, reduce engine performance and increase fuel consumption. Mineral spirit is among the most widely used of those hydrocarbons, due to its low commercial value and easiness of mixing with gasoline. This research work is concerned with the influence of mineral spirit on the physicochemical properties of gasoline, in particular its distillation curve and octane number. The results of tests on gasoline samples containing different amounts of mineral spirit show that, although this hydrocarbon greatly modifies the distillation curve of gasoline, it does not breach legal limits, even at concentrations as high as 19,5%. With regard to octane number and anti-knock index it behaves likewise, since the reduction observed is too small to breach legal limits. These results indicate that it is relatively easy to adulterate fuel within legal limits, with very damaging consequences to the society as a whole. (author)

  4. Perovskites synthesis for solid oxide fuel cells; Sintese de perovsquitas para celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sibelle F.C.X.; Melo, Dulce M.A.; Pimentel, Patricia M.; Melo, Marcus A. Freitas; Martinelli, Daniele M.H. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Quimica]. E-mail: sibelle.cunha@gmail

    2008-07-01

    This work aims to study on the obtaining powders of lanthanum manganite oxides with partial substitution of La with strontium at 20% for the application as a cathode for solid oxide fuel cell, through a route of synthesis that are similar to the Pechini method, in which gelatin replaces the ethylene glycol as polymerization agent. The method highlights itself due to its simplicity, low cost and capability to obtain crystalline powders with the high purity and good stoichiometric control. The perovskite obtained were characterized by thermogravimetric analysis, X ray diffraction, electronic scanning microscopy and the superficial area by BET method. The deposition of the perovskite on electrolyte/anode system was done through the spin coating technique. The methodology used for the perovskite synthesis was very efficient, considering a monophasic material was obtained and with characteristics that were proper to the application as electrode to solid oxide fuel cells. (author)

  5. Fuel cells cathode with multiple catalysis and electrocapillary convection; Catodo de celula a combustivel com catalise multipla e conveccao eletrocapilar

    Energy Technology Data Exchange (ETDEWEB)

    Bambace, Luis Antonio Waack; Nishimori, Miriam; Ramos, Fernando Manuel [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)], e-mail: bambace@dem.inpe.br; Bastos Netto, Demetrio [Instituto Nacional de Pesquisas Espaciais (INPE), Cachoeira Paulista, SP (Brazil)

    2004-07-01

    This paper discusses a mathematical model for the chemical reactions and liquid phase flow processes occurring in a fuel cell cathode through non homogeneous catalysis carried by gold and Prussian Blue. The gold is applied inside the porous walls of micro-tubes, which may be obtained through several methods. The wall porosity ranging from 7 to 30% ensures gas exchange between the interior of a micro-tube and its exterior where gas flow takes place. The Prussian Blue consists of a thin porous layer located between the selective membrane and the micro-tube system, with void fraction in the 70 to 80% range. A porous electricity conducting carbide flux collector is placed between the tube system and the bipolar plates. The system return tubes possess a diameter much larger than one of the micro-tubes. The electric potential differences generated by the ionic currents in the system and its asymmetrical shape are used to generate electrocapillary flows, which are related with the surface tension changes with local potential. The hydrogen peroxide concentration and its transport to the Prussian Blue layer, and the oxygen transport inside the reactive tubular system are analyzed in this work. (author)

  6. Evaluation of sulphonated polycarbonate membranes for fuel cells; Avaliacao de membranas de policarbonato sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Isabela M.M.; Gomes, Ana C.; Pessan, Luiz A. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais], e-mail: isabelamuglia@gmail.com; Paranhos, Caio [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2011-07-01

    Fuel cells based on ion conducting polymer membranes offer an alternative for the conventional energetic matrices. Among many advantages of this system, we can mention the reduction on the emission of pollutants, high efficiency and simplicity. This work presents the modification of polycarbonate by sulfonation reaction using acetyl sulfate, in order to increase the conductor ionic character of the membranes used as electrolytes for hydrogen fuel cells. The sulfonated polycarbonate membranes were obtained by casting and then characterized by Fourier transform infrared spectroscopy, water vapor transmission, differential scanning calorimetry, thermogravimetric analysis and viscosimetry. (author)

  7. Electrochemical characterization of proton exchange membrane fuel cells; Caracterizacao eletroquimica de celulas a combustivel de membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: furtado@cepel.br; Codeceira Neto, Alcides [Companhia HidroEletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    This paper describes the electrochemical behavior of a proton exchange membrane fuel cell in function of temperature and time of operation. Different polarization phenomena are considered in the 30 to 70 deg C temperature range, as well as the degradation of electrochemical behavior of the fuel cell analyzed up to 1260 hours of operation. The results show that there is a tendency for the experimental values approaching the theoretical as it increases the temperature of the membrane electrolyte. The electrochemical behavior of the PEMFC studied proved to be less stable at 70 deg C. On the other hand, at 30 deg C the fuel cell performance proved to be considerably lower than at other temperatures. Also, it was found that in certain current ranges occurs greater overlay in potential-current curves, and in some cases reversing between these curves depending on the electric current required for the data obtained at 60 and 70 deg C, indicating, perhaps, that at 70 deg C the characteristics of the electrolyte are slightly inferior to those at 70 deg C, corresponding to an electrolyte degradation. Additionally, for the system studied, we found that the rate of variation of the potential difference in function of the temperature is quite high at the beginning of the operation process and tends to stabilize in a level of around 2,3-2,5 {mu}V per minute for times greater than 330 hours of operation. (author)

  8. Experimental study of proton exchange membrane fuel cell; Estudo experimental de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Luis Evelio Garcia; Oliveira, Amir Antonio Martins [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica], e-mail: evelio@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    Here we present a thermodynamic and chemical kinetic analysis of the methane steam reforming for production of 5 kw of electrical power in a PEM fuel cell. The equilibrium analysis is based on the method of element potentials to find the state of minimum Gibbs free energy for the system and provides the equilibrium concentration of the reforming products. The objective of this analysis is to obtain the range of reforming temperature, pressure and steam-methane molar ratio that results in maximum hydrogen production subjected to low carbon monoxide production and negligible coke formation. The thermal analysis provides the heat transfer rates associated with the individual processes of steam production, gas-phase superheating and reforming necessary to produce 5 kw of electrical power in a PEM fuel cell and allows for the calculation of thermal efficiencies. Then, the chemical reaction pathways for hydrogen production in steam reforming are discussed and the available chemical, adsorption and equilibrium constants are analyzed in terms of thermodynamic consistency. This analysis provides the framework for the reactor sizing and for establishing the adequate operation conditions. (author)

  9. Experimental analysis of a PEM fuel cell 15 W; Analise experimental de uma celula a combustivel PEM 15W

    Energy Technology Data Exchange (ETDEWEB)

    Miyake, Raphael Guardini; Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: miyake@labcet.ufsc.br, e-mail: ebazzo@emc.ufsc.br

    2006-07-01

    Fuel cells have been considered a promising alternative for electric energy generation. In order to contribute with the development of this technology, a PEM fuel cell was installed and new experiments were carried out at LabCET (Laboratory of Combustion and Thermal System Engineering). Previous results have shown polarization curves identifying the need of rigorous controlling of humidification temperature of the fuel cell. In this paper, new results were carried out considering the use of a fan connected to the fuel cell and possible degradation in the electrolyte, after a relative long time operation. New polarization curves were plotted for comparison with previous results. (author)

  10. Systems of three generation using fuel cells; Sistemas de trigeracao com o uso de celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    San Martin Diaz, Jose Ignacio; Aperribay Maiztegui, Victor; San Martin Diaz, Jose Javier [Escuela Universitaria de Ingenieria Tecnica Industrial de Eibar, Guipuzcoa, Pais Vasco (Spain); Zamora Belver, Inmaculada; Eguia Lopez, Pablo [Escuela Tecnica Superior de Ingenieria de Bilbao (Spain)

    2010-10-15

    The three generation includes production processes and simultaneous use oe electric power, heat and cold from a fuel source providing global high energy efficiency, reduction of emission of gases in the atmosphere, losses of investments, and more reliability in the supply. This paper approaches the use of fuel cells for three generation, and presents different subsystems of generation with the main characteristics and applications. (author)

  11. Direct fuel injection in spark ignition engines; Injecao direta de combustivel em motores de ignicao por centelha

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Rodrigo Fernando Estella dos; Hildebrand Junior, Leonidas; Passarini, Luis Carlos; Santos, Antonio Moreira dos; Bezerra, Adriano Carlos Nogueira [Sao Paulo Univ., Sao Carlos, SP (Brazil). Dept. de Engenharia Mecanica]. E-mail: santosrf@sc.usp.br

    2000-07-01

    This paper presents the state-of-art of the fuel direct electronic injection, specifically the Otto cycle, the present technology for feasibility of the utilization, the characteristics of the engine using this system, by comparison with systems using the indirect fuel injection, the obtained results with laboratory experiments performed in direct and indirect fuel injection and conclusions as well.

  12. Development of solid oxide fuel cells (SOFC); Desenvolvimento de celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Souza, F.M.B. de; Carvalho, L.F.V. de; Alencar, M.G de; Boaventura, J.S. [Universidade Federal da Bahia (DFQ/UFBA), Salvador, BA (Brazil). Dept de Fisico-Quimica. Grupo de energia e Ciencias dos Materiais], e-mail: bventura@ufba.br

    2008-07-01

    The most promising technology for generating electric power, with reduced environmental impact, is the fuel cell. This technology is virtually non-polluting and the fuel supplies can be renewable. Therefore is necessary to study the technique of preparing the entire anode / electrolyte / cathode to optimize its operation. There are still major challenges to making the SOFC economically viable. The key is the improvement of manufacturing of its components and use of materials that can simultaneously reduce costs and reduce the temperature of operation. Among the properties of the cell, was shown the dependence of the efficiency of the device on the properties of the electrolyte, particularly its thickness. The mixture of YSZ with GDC in the composition of the anode and electrolyte aims to obtain a material with greater ionic conductivity. After sintering the cell was characterized by scanning electron microscopy (SEM). (author)

  13. Sludge dewatering on filters aiming the utilization as fuel; Desaguamento de lodos em filtro visando aproveitamento como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Paschoalim, Luis Gustavo; Neves, Jose Mangolini

    1992-12-31

    This work presents modern methodologies for sludge dewatering and alternatives for environmental disposal of the so obtained cakes. Among the possible alternatives, special emphasis is given to the characterization and study of the variables which determine the behaviour of dewatering operation of sludges form pulp and paper industries. Results are presents for bench scale tests and pilot plant tests 28 refs., 9 figs., 7 tabs.

  14. Poly (ether ether ketone) membranes for fuel cells; Membranas de poli (eter eter cetona) sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D., E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Hui, Wang S. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Oliveira, Vivianna S. de [Escola Tecnica Rezende-Rammel, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

  15. Sipping test on a failed MTR fuel element; Teste de sipping em um elemento combustivel tipo placa falhado

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis Antonio Albiac; Zeituni, Carlos Alberto; Silva, Antonio Teixeira e; Perrotta, Jose Augusto; Silva, Jose Eduardo Rosa da [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear

    2002-07-01

    This work describes sipping tests performed on MTR fuel elements of the IEA-R1 research reactor, in order to determinate which one failed in the core during a routine operation of the reactor. radioactive iodine isotopes {sup 131} I and {sup 133} I, employed as failure indicators, were detected in samples corresponding to the fuel element IEA-156. The specific activity of each sample, as well as the average leaking rate, were measured for {sup 137} Cs. The nuclear fuels U{sub 3} O{sub 8} - Al dispersion and U - Al alloy were compared concerning their measured average leaking rates of {sup 137} Cs. (author)

  16. Technical analysis of fuel cells applied to cogeneration systems; Analise tecnica de celulas combustivel aplicadas em sistemas de cogeracao

    Energy Technology Data Exchange (ETDEWEB)

    Pulgar, Rafael Girardi; Bazzo, Edson [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mails: rafael@cet.ufsc.br; ebazzo@emc.ufsc.br; Martinac, Ivo [KTH - Royal Institute of Tech., Stockholm (Sweden). Dept. of Energy Technology]. E-mail: im@egi.kth.se

    2002-07-01

    In the last years the fuel cell technology has been pointed out as a promising alternative for electricity generation. Compared to conventional energy conversion processes it presents great advantages, such as high efficiency, low gases emissions and the possibility to be applied in cogeneration systems, among others. The fuel cell converts the chemical energy of the fuel directly into electricity via an electrochemical process. The waste heat generated in the process can be recovered in cogeneration applications. In this article, preliminary results related to a Phosphoric Acid Fuel cell (PAFC) applied to hotels for power generation and hot water production are presented. The PAFC shows an electrical efficiency of about 40 per cent for power generation. In the cogeneration system proposed in this work, the global thermoelectric efficiency increased up to 73 per cent, when both electrical and thermal energy are considered. (author)

  17. Influence of the fuel in the nanostructure catalyzer oxides synthesis; Influencia do combustivel na sintese de oxidos catalisadores nanestruturados

    Energy Technology Data Exchange (ETDEWEB)

    Zampiva, R.Y.S.; Panta, P.C.; Carlos, R.B.; Alves, A.K.; Bergmann, C.P., E-mail: rubiayoungsun@gmail.com [Universidade Federal do Rio Grande do Sul (LACER/UFRGS), Porto Alegre, RS (Brazil). Lab. de Ceramicos

    2012-07-01

    Among the techniques used in catalysts production, the solution combustion synthesis (SCS) has been increasingly applied due the possibility of producing, at low cost, highly pure and homogeneous nanostructured powders. The smaller the particle diameter, the greater the activity of the catalyst. In SCS, the size of the particles produced depends on the process variables. In order to formulate the optimal methodology for the preparation of nanostructured oxides for catalysis, it was studied the fuel-oxidant concentration ratio, and the use of glycine and polyethylene glycol with molecular weight 200 (PEG 200) as fuel in the SCS of Iron, Magnesium and Molybdenum based catalysts. The phase identification of the products was performed by x-ray diffraction (XRD). Particle size and surface area analysis were done to characterize the particles size and the samples morphology was obtained by scanning electron microscopy. Results indicated the formation of high purity nanomaterials obtained for low concentrations of fuel, and a wide variation in the nanostructure sizes depending on the concentration and type of fuel used. (author)

  18. Performance of a cycle Otto engine using biogas; Desempenho de um motor ciclo Otto utilizando biogas como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Juliano de [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas], e-mail: jsouza@unioeste.br; Souza, Samuel N. Melegari de [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil)], e-mail: ssouza@unioeste.br; Machado, Paulo Romeu M. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Engenharia Mecanica

    2004-07-01

    The rising of the oil prices is increasing the search for alternative fuels. Brazil has a great availability of biogas from anaerobic digestion in the rural area, urban waste in the landfills and treatment of the municipal sewer. In this work were evaluated in dynamometer a cycle Otto engine using biogas, and were obtained the characteristics curves of torque and power. First was done the evidence test with gasoline, biogas and natural gas, using commercial systems for this fuels, using as comparison for other tests. After has been done tests for some combinations of ignition point, mixer of gas and compression tax. By the analysis of the results has been concluded that the better results for power and torque using biogas as fuel were with a tax compression of 12,5:1, gas mixer long and ignition point advanced in 45 deg. (author)

  19. Sugarcane bioethanol and the sustainable development; Alcool combustivel derivado da cana-de-acucar e o desenvolvimento sustentavel

    Energy Technology Data Exchange (ETDEWEB)

    Leme, Rodrigo Marcelo [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Programa de Pos-graduacao em Planejamento de Sistemas Energeticos

    2004-07-01

    The use of the sugarcane bioethanol in Brazil was strongly boosted during the 1970 's and 1980 's, with the advent of the National Alcohol Programme (PROALCOOL). Following this period a decade of uncertainties came up, when the decline in the Program results were noticeable. Nowadays, it seems that new and good perspectives arise, due to the emergent external and internal markets. In this paper the evolution of the sugarcane bioethanol use in Brazil is addressed, stressing the importance and legacy of the PROALCOOL. The future perspectives of the alcohol are also discussed. (author)

  20. Bio-flex obtained from pyrolysis of biomass as fuel; Bio-flex obtido da pirolise de biomassa como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Mesa Perez, Juan Miguel; Viltre Rodriguez, Roberto Alfonso; Marin Mesa, Henry Ramon [Bioware Tecnologia, Campinas, SP (Brazil); Rocha, Jose Dilcio [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico; Samaniego, Manuel Raul Pelaez [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Planejamento de Sistemas Energeticos; Cortez, Luis Augusto Barbosa [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola

    2006-07-01

    This paper describes the BIOWARE experience in the bio fuel production from biomass residues. Fast pyrolysis of a mixture of sugar cane trash and elephant grass carried out in a fluidized bed reactor with capacity of 200 kg/h dry feed (12% w/w). The co-products particulate charcoal, acid extract, and bio-oil were obtained. The fast pyrolysis pilot plant PPR-200 belonged to UNICAMP and is operated by BIOWARE personnel. This paper presents the chemical rote to bio-flex production (a kind of bio diesel from acid esterification) from pyrolytic carboxylic acids. Both ethanol and methanol were used as reactant but higher yields were found with methanol. (author)

  1. Use of biomass as fuel for Stirling motors; Uso de biomassa como combustivel para acionamento de motores Stirling

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Robledo Wakin; Aradas, Maria Eugenia Coria; Cobas, Vladmir Rafael Melian; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Estudos em Sistemas Termicos], e-mail: robledo@unifei.edu.br

    2004-07-01

    The search to increase the electrical generation, together with the need to decrease the pollution emission, has encouraged the alternative energy sources. Nowadays around the world there are a lot of alternative energy sources incentive programs. In Brazil have PROINFA - Alternative Energy Sources Incentive Program. An example of alternative energy sources is the use of biomass as combustible. In the electrical generation, the biomass can be used directly, having it's directly combustion, and transforming the thermal energy liberated in electrical energy, or can be transformed in gas or liquid, and after use technology as internal combustion engine and gas turbine to generate electricity with these combustibles. Few technologies can be used to generate electricity burning directly to the biomass. Among these technologies, have the Stirling engine. It is possible to use this engine because the Stirling engines are external combustion engines, and it has not contact between the work gas and the flue gas. In this way, the Stirling engine needs a heat source, independent of the combustible type that will be used, including solar source. In this work will be present this technology, the different kinds of Stirling engines according to their configuration, moreover will be present the ST 05 G Stirling engine, which is a 500 W engine, acquired by University Federal of Itajuba. Also are present the tests results of this engine, and the installation to work with wood waste as combustible. (author)

  2. Evolutionary neural networks: a new alternative for neutron spectrometry; Redes neuronales evolutivas: una nueva alternativa para la espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M. [Departamento de Electrotecnia y Electronica, Escuela Politecnica Superior, Av. Menendez Pidal s/n, 14004 Cordoba (Spain); Martinez B, M. R.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Galleo, E. [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid, Jose Gutierrez Abascal 2, 28006 Madrid (Spain)], e-mail: morvymm@yahoo.com.mx

    2009-10-15

    A device used to perform neutron spectroscopy is the system known as a system of Bonner spheres spectrometer, this system has some disadvantages, one of these is the need for reconstruction using a code that is based on an iterative reconstruction algorithm, whose greater inconvenience is the need for a initial spectrum, as close as possible to the spectrum that is desired to avoid this inconvenience has been reported several procedures in reconstruction, combined with various types of experimental methods, based on artificial intelligence technology how genetic algorithms, artificial neural networks and hybrid systems evolved artificial neural networks using genetic algorithms. This paper analyzes the intersection of neural networks and evolutionary algorithms applied in the neutron spectroscopy and dosimetry. Due to this is an emerging technology, there are not tools for doing analysis of the obtained results, by what this paper presents a computing tool to analyze the neutron spectra and the equivalent doses obtained through the hybrid technology of neural networks and genetic algorithms. The toolmaker offers a user graphical environment, friendly and easy to operate. (author)

  3. DETERMINAÇÃO DE ESTANHO EM AMOSTRAS AMBIENTAIS POR ESPECTROMETRIA DE FLUORESCÊNCIA ATÔMICA

    Directory of Open Access Journals (Sweden)

    Daniel L. Garcez

    2016-07-01

    Full Text Available An analytical method to determine tin concentrations in natural samples, by coupling atomic fluorescence spectrometry, hydride generation and flow injection system was developed. The sample digestion procedure and the conditions of hydride generation were fully optimized. The best conditions for the generation of SnH4 were obtained with NaBH4 4% (m v-1 and HCl 0.6 mol L-1. The optimized flow rates were 1.2 mL min-1 for sample, 1.2 mL min-1 for HCl and 1.6 mL min-1 for NaBH4 solution. The sample volume was 500 µL. The best acid volume for digestion of solid samples was stablished to be 3 mL HNO3 + 1 mL HCl. The accuracy of the method was established by the analysis of certified reference materials and by comparative determinations, using inductively coupled optical emission spectrometry. The approach developed was shown to offer a robust method with excellent accuracy and precision for the determination of Sn in environmental samples. Finally, the method was applied to analyse the soil, sediment and water samples, collected in area under anthropogenic activities: processing area of cassiterite in Corumbataí/SP. The obtained data indicated that there was alteration in the natural quality of the environment as a result of the activities developed in that site

  4. Chemical vapor deposition (CVD) of uranium for alpha spectrometry; Deposicion quimica de vapor (CVD) de uranio para espectrometria alfa

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez V, M. L.; Rios M, C.; Ramirez O, J.; Davila R, J. I.; Mireles G, F., E-mail: luisalawliet@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2015-09-15

    The uranium determination through radiometric techniques as alpha spectrometry requires for its proper analysis, preparation methods of the source to analyze and procedures for the deposit of this on a surface or substrate. Given the characteristics of alpha particles (small penetration distance and great loss of energy during their journey or its interaction with the matter), is important to ensure that the prepared sources are thin, to avoid problems of self-absorption. The routine methods used for this are the cathodic electro deposition and the direct evaporation, among others. In this paper the use of technique of chemical vapor deposition (CVD) for the preparation of uranium sources is investigated; because by this, is possible to obtain thin films (much thinner than those resulting from electro deposition or evaporation) on a substrate and comprises reacting a precursor with a gas, which in turn serves as a carrier of the reaction products to achieve deposition. Preliminary results of the chemical vapor deposition of uranium are presented, synthesizing and using as precursor molecule the uranyl acetylacetonate, using oxygen as carrier gas for the deposition reaction on a glass substrate. The uranium films obtained were found suitable for alpha spectrometry. The variables taken into account were the precursor sublimation temperatures and deposition temperature, the reaction time and the type and flow of carrier gas. Of the investigated conditions, two depositions with encouraging results that can serve as reference for further work to improve the technique presented here were selected. Alpha spectra obtained for these depositions and the characterization of the representative samples by scanning electron microscopy and X-ray diffraction are also presented. (Author)

  5. Tracking and uncertainty in absorption spectrometry and atomic emission; Trazabilidad e incertidumbre en espectrometria de absorcion y emision atomica

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu Torres, Maria del Rocio; Ramirez Cruz, Pedro [Centro Nacional de Metrologia (CENAM), Division de Materiales Metalicos, Area de Metrologia de Materiales, Departamento de Educacion Continua, El Marquez, Queretaro (Mexico)

    2008-04-18

    In this course it is described what methodology is, the measuring instruments and the importance of its calibration. The history of the International System of Units is described and what the meaning of tracking is. Also the general concepts of uncertainty in analytical measurements are shown, such as the measurements of central tendency and the variability measurements. [Spanish] En este curso se describe que es metodologia, los instrumentos de medicion y la importancia de calibrarlos. Se describe la historia del Sistema Internacional de Unidades y que es la trazabilidad. Tambien se presentan conceptos generales de incertidumbre en mediciones analiticas, como las medidas de tendencia central y las medidas de variabilidad.

  6. X-ray fluorescence spectrometry applied to soil analysis; Espectrometria de fluorescencia de raios X aplicada as analises de solo

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako; Scapin Junior, Wilson Santo; Scapin, Marcos Antonio; Imakima, Kengo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). E-mail: vsalvado@baitaca.ipen.br; imsato@net.ipen.br; kengo@sup.ipen.br

    1997-07-01

    This paper studies the X-ray fluorescence spectrometry applied to the soil analysis. A comparative study of the WD-XRFS and ED-XRFS techniques was carried out by using the following soil samples: SL-1, SOIL-7 and marine sediment SD-M-2/TM, from IAEA, and clay, JG-1a from Geological Survey of Japan (GSJ)

  7. Plutonium determination in urine by techniques of mass spectrometry; Determinacion de plutonio en orina por tecnicas de espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of {sup 239}Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of {sup 239}Pu). (author)

  8. Methods of calculus for neutron spectrometry in proportional counters; Metodos de calculo para espectrometria de neutrones en contadores proporcionales

    Energy Technology Data Exchange (ETDEWEB)

    Butragueno, J. L.; Blazquez, J. B.; Barrado, J. M.

    1976-07-01

    Response functions for cylindrical proportional counters with hydrogenated gases have been determined, taking in account only wall effect, by means of two independent calculus methods. One of them is a Monte Carlo application and the other one analytica at all. Results of both methods have been compared. (Author)

  9. Composição de voláteis e perfil de aroma e sabor de méis de eucalipto e laranja

    Directory of Open Access Journals (Sweden)

    Bastos Deborah Helena Markowicz

    2002-01-01

    Full Text Available Neste trabalho foram analisados os compostos voláteis de amostras de mel de eucalipto e laranja colhidos nos estados de São Paulo e de Minas Gerais. O isolamento dos voláteis foi realizado empregando-se uma técnica de ''headspace'' dinâmico, a separação efetuada por cromatografia gasosa de alta resolução e a identificação por espectrometria de massas, Índices de Kovats e padrões, quando disponíveis. Foram identificados no mel de laranja o benzaldeído, o óxido cis de linalol, n-heptanal, 6-metil-5-hepten-2-ona, octanal e fenilacetaldeído, e em mel de eucalipto, o nonanal, 2-heptanona, 2-heptanol, octanol e nonanol. A caracterização sensorial desses méis foi obtida por Análise Descritiva Quantitativa e a aplicação de Análise dos Componentes Principais aos dados revelou que os descritores ''queimado'' e ''sabor residual'' caracterizam o mel de eucalipto, enquanto ''floral'' e ''cera'' caracterizam o mel de laranja. Entre os compostos identificados, o nonanal e o nonanol apresentaram contribuição sensorial importante ao mel de eucalipto, enquanto o fenilacetaldeído e o benzaldeído foram relacionados com os principais descritores do mel de laranja.

  10. Determinação do valor de referência do aluguel de imóveis residenciais empregando o Método TODIM

    Directory of Open Access Journals (Sweden)

    Luís Alberto Duncan Rangel

    2007-08-01

    Full Text Available As avaliações de alternativas em presença de múltiplos critérios, quantitativos e qualitativos, são realizadas nas mais diversas áreas. Este artigo apresenta um estudo dessa natureza, conduzido junto às imobiliárias da cidade de Volta Redonda, RJ, visando auxiliar a definição do valor de referência de aluguel de imóveis residenciais. Para isto, faz-se uso do método TODIM, do Apoio Multicritério à Decisão. Com a finalidade de obter os valores de referência o mais próximo possível dos valores de mercado, alguns imóveis que tinham acabado de ser alugados foram inseridos na pesquisa, conhecendo-se desta forma o seu valor de aluguel. Assim, ao empregar o Método TODIM para realizar a ordenação dos imóveis com diferentes características, em função dos critérios empregados na análise e de suas importâncias relativas para os decisores, obtém-se a ordenação de todos os imóveis, e, como conseqüência disto, chega-se às diversas faixas de valor de aluguel dos imóveis em estudo. Uma análise de sensibilidade dos resultados numéricos obtidos complementa o estudo.Setting rent reference values for residential housing units is normally performed under multiple, conflicting criteria. This article shows how the TODIM method of Multicriteria Decision Aiding can be of a significant help in that task. A case study was carried through in the city of Volta Redonda, in the State of Rio de Janeiro, Brazil. The TODIM method allows considering quantitative as well as qualitative evaluation criteria and is founded on Prospect Theory. In order to obtain a maximum adherence of rent reference values to market values, some housing units that had just been rent were taken into account in the study. The application of the TODIM method produced the ordering of all such housing units and then led to identifying ranges for rent. A sensitivity analysis complemented the study by providing useful insights on the numerical results that were obtained.

  11. EMPREGANDO A MATEMÁTICA: UMA EXPERIÊNCIA COM O MUNDO DO TRABALHO. EMPLOYING MATHEMATICS: AN EXPERIENCE WITH THE WORLD OF LABOR

    Directory of Open Access Journals (Sweden)

    Amal Rahif Suleiman

    2013-12-01

    Full Text Available O presente relato é uma experiência desenvolvida em uma escola de Ensino Médio da rede estadual de ensino de São José do Rio Preto, São Paulo, Brasil, com o objetivo de promover e aumentar atitudes positivas diante dos conteúdos escolares de Matemática. Nas atividades relatadas, alunos da 2ª série do Ensino Médio investigaram e representaram suas pesquisas sobre a presença e a importância das ferramentas da Matemática no mundo do Trabalho e, em consequência, nas ações diárias de profissionais de diversas áreas do conhecimento. As reflexões sobre a experiência ocorrida permitem inferir que ao: 1 se encontrarem com a influência da Matemática na realidade social, nas situações do cotidiano de “trabalhadores”, 2 constatarem que a Matemática foi construída ao longo dos séculos com estudo e “trabalho” de muitos matemáticos e 3 verificarem que em numerosos cursos de graduação existem disciplinas que, direta ou indiretamente, são de conteúdo matemático; houve uma maior participação dos estudantes nas aulas, passaram a ver os assuntos com significado e a valorizar o fato de aprender com profundidade. This paper reports an experience developed in a public high school in São José do Rio Preto, São Paulo, Brazil, aiming at promoting and increasing positive attitudes related to school mathematics content. In the reported activities, students from the 2nd year of high school investigated and presented their research on the presence and importance of the mathematics tools in the world of labor and, therefore, the daily actions of professionals from various fields of knowledge. The reflections on this experience allow inferring that when: 1 meeting with the influence of mathematics in social reality, in everyday situations of “workers”, 2 realizing that mathematics has been built over the centuries by the studies and “work” of many mathematics and 3 finding out that in many undergraduate courses there are disciplines that, directly or indirectly, deal with mathematical content, there was a greater participation of students in classes, as they started to see the meaning of the issues studied and the value of learning them.

  12. Desenvolvimento de sistemas líquido-cristalinos empregando silicone fluido de co-polímero glicol e poliéter funcional siloxano

    OpenAIRE

    Chorilli, Marlus; Prestes, Paula Souza; Rigon, Roberta Balansin; Leonardi, Gislaine Ricci; Chiavacci, Leila Aparecida; Scarpa,Maria Virgínia

    2009-01-01

    For the construction of the phase diagrams, the method of the aqueous titration was used. There were prepared 5 ternary diagrams, varying the surfactant and the oil phase. The liquid-crystalline phases were identified by polarized light microscopy. The formulations prepared with silicon glycol copolymer, polyether functional siloxane (PFS) and water (S1) and with diisopropyl adipate, PFS and water (S4) presented liquid-crystalline phases with lamellar arrangement. Moreover, after 15 days in h...

  13. Análise da variação longitudinal do esqueleto axial em Serpentes (Squamata) empregando ferramentas de morfometria geométrica

    OpenAIRE

    Fabio de Andrade Machado

    2010-01-01

    As cobras são um grupo de vertebrados extremamente bem sucedido. Apesar da aparente simplicidade, elas conseguiram ocupar uma grande diversidade de habitats. O esqueleto axial das serpentes apresenta relação com vários aspectos da vida que puderam ter tido influência direta em seu sucesso evolutivo. Além disso, a forma dos elementos vertebrais possui valor taxonômico, fato que desperta particular interesse, visto que a maior parte do registro fóssil deste grupo é constituído por elementos ver...

  14. Analysis of the microturbine combustion chamber by using the CHEMKIN III computer code; Analise da camara de combustao de microturbinas empregando-se o codigo computacional CHEMKIN III

    Energy Technology Data Exchange (ETDEWEB)

    Madela, Vinicius Zacarias; Pauliny, Luis F. de A.; Veras, Carlos A. Gurgel [Brasilia Univ., DF (Brazil). Dept. de Engenharia Mecanica]. E-mail: gurgel@enm.unb.br; Costa, Fernando de S. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Combustao e Propulsao]. E-mail: fernando@cptec.inpe.br

    2000-07-01

    This work presents the results obtained with the simulation of multi fuel micro turbines combustion chambers. In particular, the predictions for the methane and Diesel burning are presented. The appropriate routines of the CHEMKIN III computer code were used.

  15. Estimação do sistema quase ideal de demanda para uma cesta ampliada de produtos empregando dados da POF de 2002-2003

    Directory of Open Access Journals (Sweden)

    José Adrian Pintos-Payeras

    2009-06-01

    Full Text Available Neste artigo são estimadas elasticidades-preço, elasticidades-cruzadas e elasticidades-dispêndio para 27 grupos de produtos a partir dos microdados da POF de 2002-2003. Para tanto, é usada a versão não-linear do sistema quase ideal de demanda (NL-AIDS. Os parâmetros do sistema são obtidos usando uma regressão aparentemente não-relacionada com iteração (ITSUR. A maioria das elasticidades-preço para produtos alimentícios apresentou valor absoluto menor do que 1. Os produtos nãoalimentícios, de uma forma geral, tampouco apresentaram alta elasticidade-preço e as elasticidades-dispêndio foram condizentes com o esperado.This paper aimed to estimate price-elasticities, cross-elasticities and expenditure-elasticities for 27 groups of products in Brazil. Brazilian Household Budgets Research (POF 2002-2003 microdata were used on the estimations of non-linear almost ideal demand systems (NL-AIDS. The parameters used in the NL-AIDS were previously estimated using iterated seemingly unrelated regressions (ITSUR. Most of the estimations showed that price-elasticities for food products are lower than one. On the other hand, non-food products did not show high price-elasticities. Expenditure-elasticities were in accordance with previous assumptions.

  16. Desenvolvimento de métodos analíticos em sistemas de soluções em fluxo empregando polifenol oxidase naturalmente imobilizada sobre tecidos vegetais

    OpenAIRE

    Antonio William Oliveira Lima

    1998-01-01

    Esta tese apresenta o desenvolvimento de metodologias analíticas em sistemas de solução em fluxo com detecção amperométrica e espectrofotométrica explorando a utilização de tecidos vegetais como fonte enzimática para a biocatálise de reações. Desempenhos satisfatórios foram obtidos com a utilização do mesocarpo fibroso do coco (Cocus nucifera, L.) e com a casca e/ou polpa de frutos da palmeira leque (Latania sp), fontes de polifenol oxidase. Uma metodologia, simples e rápida, para a determina...

  17. Identificação de microcistina LR ao nível molecular empregando microscopia de força atômica

    Directory of Open Access Journals (Sweden)

    Augusto Etchegaray

    2010-01-01

    Full Text Available Microcystins are non-ribosomal peptides that must be detected for its health concern. Here, microcystin LR and its specific antibody were respectively tethered to the substrate and to the tip of an atomic force microscope, after surface functionalization using 3-aminopropyltriethoxysilane and glutaraldehyde. Functionalization was confirmed comparing topographic images taken on bare and modified tips. Force versus distance curves were successfully used to measure the specific antibody-antigen interactions comparing with a control in which microcystin was initially blocked by incubation with free antibodies. The results showed unequivocally the specific recognition of MLR, suggesting that this method could be useful for biosensor development.

  18. Supervision and control system for greenhouses using wireless network sensors; Sistema de supervisao e controle para casas de vegetacao empregando rede 'wireless' de sensores

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Ivo Reis; Cagnon, Jose Angelo; Rodrigues, Ricardo Martini [Universidade Estadual Paulista (UNESP), Bauru, SP (Brazil). Fac. de Engenharia. Dept. de Engenharia Eletrica], e-mail: ivo@feb.unesp.br, e-mail: martini@feb.unesp.br, e-mail: jacagnon@feb.unesp.br

    2004-07-01

    The present work had as objective the configuration of a supervision and control system for greenhouses applications using a system of data collection of control parameters through a wireless communication network. In agreement with the adopted methodology, its development was accomplished in three different phases. Initially the hardware modules for a Sensors Unit, a Data Concentrator Unit and a capacitive type soil moisture sensor were developed. Soon afterwards an application was configured through a SCADA supervision and control program, the Ellipse PRO, dedicated to the supervision and control of a green house. In the final phase the necessary data were collected for the training of an artificial neural network that is integral part of the humidity sensor. The Sensors Unit and the Data Concentrator Unit were developed starting from microcontrollers of low consumption and high performance and presents excellent cost/benefit relationship. These units are used in the acquisition and data storage of in comings from several sensors applied in the installation. In order to eliminate the inconveniences of a system that uses nets of electric cables connections links of RF was used, with pattern of message of the protocol MODBUS/RTU, for the communication among these units. The application developed through the Ellipse FOR is composed of a group of screens that represents in a virtual way the complete green house environment. Through these screens the operator can alter the operation state of each one of the elements involved in the irrigation and climatization control process. According the cost characteristics, operation flexibility and existent functionality this system represents a solution economically viable in the automation green houses. It can be affirmed that this configuration represents an innovative solution and that can contribute in much for the improvement of cultivated species as well as to provide the necessary ways for the rational use of the resources and production inputs, especially the electric power. (author)

  19. Evaluation of urban and industrial wastewater treatment plants using radioactive tracers; Otimizacao de unidades de tratamento de aguas residuais urbanas e industriais empregando-se tracadores radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis Eduardo Barreira

    2001-07-01

    A methodology for studies and evaluation of sewage treatment plants with radioactive tracers is presented.. Radioisotopes as {sup 82} Br ( for the liquid phase), {sup 110m} Ag and {sup 140} La, (for the solid phase) was used to evaluate sewage flow rates, mixing pattern in equalization tank and test effluent treatment units. The tracer was injected in the unit (instantaneously or in a constant rate with a pump) and NaI-scintillation detectors measured the output signal. The Fortran program TRACADORES was developed to analyze the response function of the units in form of residence times distribution curves (RTD), which represents the probability of an element of the material to interact with the unit, and calculate the mean residence time {gamma}, the central moment of this distribution function. This fundamental parameter characterizes the tank and serves as a quantitative evaluation for its performance. With the radiotracer techniques was possible to identify dead zone, channeling, internal circulation of the solid phase inside the tanks. The technique represents a guideline for redesign a imperfect unit and eliminate the problem. (author)

  20. Doseamento microbiológico de apramicina - desenvolvimento e validação de método empregando leitura cinética em microplacas

    OpenAIRE

    Felipe Rebello Lourenço

    2009-01-01

    O princípio do ensaio turbidimétrico é simples: a solução-teste é adicionada à suspensão do microrganismo-teste em meio de cultura, a mistura é incubada em condições adequadas e o crescimento microbiano é medido através da leitura fotométrica. O emprego de método de microplacas com leitura cínética para a dosagem de antibióticos é de interesse considerável, uma vez que possibilita reduzir quantidade de material e tempo de análise necessários e permite o ensaio de grande número de amostras sim...

  1. Development of nanocomposites employing high-density polyethylene and organo clay;Desenvolvimento de nanocompositos empregando polietileno de alta densidade e argila organofilica

    Energy Technology Data Exchange (ETDEWEB)

    Lessa, Tathiane C. Rodrigues F.; Tavares, Maria Ines B.; Pita, Vitor J.R.R., E-mail: tathianecr@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2009-07-01

    The purpose of this study was to prepare nanocomposites of high-density polyethylene and montmorillonite organoclay by polymer melt intercalation, employing different processing parameters. Effective clay incorporation into polyethylene matrix was observed. The nanocomposites were structurally characterized. Intercalated nanocomposites were obtained from different process parameters, employing polyethylene resin and montmorillonite organoclays. The XRD results and other analysis showed that the processing parameters affect the organoclay delamination. The polyethylene nanocomposite presented the better performance using twin screw extruder, at 90 rpm. The purpose of characterization of polyethylene/organoclay nanocomposite by low-field NMR showed that this technique was important to understand changes in the molecular mobility of polyethylene when organoclay was incorporated. (author)

  2. Estimativa dos pKa da Rutina empregando modelos semi-empíricos de cálculo mecânico-quântico

    OpenAIRE

    Euqueres, Jander Silva

    2009-01-01

    Neste trabalho, propriedades moleculares e termodinâmicas da molécula da rutina na fase gasosa e em meio aquoso, com a inserção de moléculas discretas de água em posições específicas, foram estudadas por meios de cálculos mecânico quânticos, utilizando especificamente como ferramenta os métodos semi-empíricos AM1 e o PM6 para o cálculo teórico do pKa. A inserção de moléculas discretas de água visou uma melhor descrição da interação soluto-solvente com o mínimo de demanda com...

  3. Avaliação das geometrias nasais de crianças empregando a rinometria acústica Evaluation of children nasal geometry, employing accoustic rhinometry

    Directory of Open Access Journals (Sweden)

    João Batista de Paiva

    2010-06-01

    Full Text Available A área anterior da cavidade nasal desempenha papel fundamental na fisiologia respiratória. OBJETIVO: Analisar durante um período do crescimento possível alteração da área transversal mínima (MCA e do volume nasal da região anterior da cavidade nasal. MATERIAL E MÉTODO: Foram avaliadas 29 crianças (14 meninos, 15 meninas com média de idade de 7,81 anos no primeiro exame (M1 e de 11,27 anos no segundo exame (M2, sem sintomas de obstrução nasal. O intervalo entre os exames foi de 36-48 meses. As crianças foram submetidas ao exame de rinometria acústica, registrando-se as áreas transversais mínimas, volumes e suas correlações com os gêneros. FORMA DE ESTUDO: Estudo de coorte. RESULTADOS: A média da área transversal da cavidade nasal de MCA para as meninas foi de 0,30±0,09cm2 (M1 e de 0,30±0,14cm2 (M2, enquanto que para os meninos foi de 0,24±0,12cm2 (M1 e de 0,32±0,10cm2 (M2. As médias dos volumes totais encontradas, para toda a amostra, foram de 2,17±0,23cm3 (MCA1-M1, 2,56±0,27cm3 (MCA1-M2, 4,24±1,17cm3 (MCA2-M2 e de 4,63±1,10cm3 (MCA2-M2. CONCLUSÃO: Não houve alteração significativa da área transversal mínima da região anterior da cavidade nasal. Não houve diferença significativa entre os gêneros, tanto para MCA como para o volume. Houve aumento significativo do volume em MCA1.The area above the nasal cavity plays a role in respiratory physiology. AIM: To analyze, during a period of growth, a possible change in the minimum cross sectional area (MCA and nasal volume of the anterior nasal cavity. MATERIALS AND METHODS: We evaluated 29 children (14 boys and 15 girls with a mean age of 7.81 years at first examination (M1 and 11.27 years in the second examination (M2, without symptoms of nasal obstruction. The interval between examinations was 36-48 months. Children were subjected to the examination of acoustic rhinometry in which we recorded the minimum cross-sectional areas, volumes and their correlations with gender. STUDY DESIGN: Cohort. RESULTS: The mean cross-sectional area of the nasal cavity of MCA for girls was 0.30 ± 0.09 cm2 (M1 and 0.30 ± 0.14 cm2 (M2, while for boys was 0.24 ± 0.12 cm2 (M1 and 0.32 ± 0.10 cm2 (M2. The mean values of the total volumes found for the whole sample were 2.17 ± 0.23 cm3 (MCA1-M1, 2.56 ± 0.27 cm3 (MCA1-M2, 4.24 ± 1.17 cm3 (MCA2- M2 and 4.63 ± 1.10 cm3 (MCA2-M2. CONCLUSION: There was no significant change in the minimum cross sectional area of the anterior nasal cavity. There was no significant difference between genders for both MCA and for the volume. There was a significant increase in MCA1.

  4. Manejo da requeima do tomateiro industrial empregando sistema de previsão Management of industrial tomato late blight using prediction system

    Directory of Open Access Journals (Sweden)

    Henrique da Silva Silveira Duarte

    2007-12-01

    Full Text Available Três experimentos foram conduzidos utilizando-se o híbrido de tomateiro industrial H 7155N, em 2003 e 2004 visando adequar um sistema de previsão modificado para o uso de fungicidas no manejo da requeima causada por Phytophthora infestans. Os experimentos foram conduzidos num delineamento em blocos ao acaso com dez tratamentos e três repetições. Os fungicidas sistêmicos foram aplicados quando o valor de severidade da doença (VSD alcançou oito, dez ou doze pontos. A alternância dos fungicidas sistêmicos com o metiram ocorreu na semana em que não foram alcançados os VSD´s. O tratamento calendário de pulverização para o controle da requeima consistiu da aplicação semanal de fungicidas após o aparecimento dos primeiros sintomas e aqueles definidos pelo sistema de previsão foram baseados nos VSD acumulados durante o experimento. A avaliação da requeima foi feita semanalmente com auxílio de uma escala descritiva de severidade e uma chave diagramática. A eficiência dos tratamentos foi comparada calculando-se a área abaixo da curva do progresso da doença, a taxa de progresso da doença (r e produtividade de tomate. Os valores de r do melhor tratamento (dimetomorfe misturado com clorotalonil (VSD = 10 alternado com metiram variaram de 0,03 a 0,07, enquanto para o tratamento calendário semanal foi de 0,05 a 0,09 e para testemunha de 0,24 a 0,39. Dimetomorfe + clorotalonil (VSD = 10 alternado com metiram produziu em média 15,7 toneladas a mais de tomate, comparado ao tratamento calendário semanal de fungicidas. Dimetomorfe ou metalaxil-M misturado com clorotalonil (VSD = 10 baseado no sistema de previsão sem a alternância com metiram diferiu do calendário semanal baseado na severidade da doença e na produção de tomate. Os tratamentos piraclostrobina misturado com metiram (VSD = 8; VSD = 10 alternado com metiram; dimetomorfe misturado com mancozeb (VSD = 8; VSD = 10 alternado com metiram proporcionaram controle intermediário da requeima. O sistema de previsão baseado no uso de dimetomorfe misturado com clorotalonil alternado com metiram (VSD = 10 permitiu redução de uma aplicação da mistura dimetomorfe misturado com clorotalonil pulverização em dois dos três experimentos, comparados ao tratamento calendário semanal de aplicação de fungicidas, sem afetar a produção.Three experiments were carried out using an industrial tomato hybrid H 7155N crop, in 2003 and 2004 seasons to fit a modified prediction system, which allows the criterious use of fungicides for the control of late blight caused by Phytophthora infestans. Trials were conducted in a randomized complete block design with ten treatments and three replications. The formulated systemic fungicides were applied when the disease severity values (DSV reached eight, ten or twelve points. On weeks where DSV's values were lower than eight, ten or twelve, metiram was applied. The traditional late blight control consisted of weekly application of fungicides after the first symptoms disease, and those defined by the prediction system were carried out based on the DSV's accumulated throughout the experiment. Late blight severity was assessed weekly by using a descriptive key and diagrammatic scale. The efficiency of the control treatments was compared by the area under the disease progress curve, disease progress rate (r and tomato yield. The r values of the best treatment (dimethomorph + chlorothalonil, DSV = 10, alternated with metiram, weekly application calendar fungicides and the check treatment varied from 0.03 to 0.07, 0.05 to 0.09 and 0.24 to 0.39, respectively. Dimethomorph + chlorothalonil DSV = 10 alternated with metiram was the most efficient and yielded more than 15,7 ton of tomato in average, above the weekly spraying calendar fungicides. Dimethomorph or metalaxyl-M mixtured with chlorothalonil (DSV = 10 based on the prediction scheme without alternation with metiram differed from the weekly spraying calendar fungicide based on disease severity and tomato yield. The treatments pyraclostrobim + metiram (DSV = 8; DSV = 10 alternated with metiram; dimethomorph + mancozeb (DSV = 8; DSV = 10 alternated with metiram gave intermediate control of late blight and tomato yield. The prediction scheme that used dimethomorph + chlorothalonil alternated with metiram (DSV = 10 allowed the reduction in one spray in two trials of the mixture dimethomorph + chlorothalonil compared to the weekly spraying calendar fungicide without any yield loss.

  5. Bacteriemia após exodontia unitária, empregando dois métodos de anti-sepsia intrabucal

    OpenAIRE

    ROCHA BARROS Valdemar Mallet da; Ito, Izabel Yoko; AZEVEDO Rosa Vitória P.; MORELLO Danielle; ROSATELI Pedro Augusto; FILIPECKI Lara Cappato

    2000-01-01

    O objetivo do trabalho foi avaliar a freqüência de bacteriemias pós-exodontia utilizando dois métodos de anti-sepsia pré-operatória, identificando os microrganismos isolados de hemoculturas pós-extração e avaliando a sua suscetibilidade a antibióticos. Vinte e seis pacientes tiveram 33 dentes extraídos. Dezesseis casos foram submetidos a anti-sepsia com bochecho com 15 ml de gluconato de clorexidina a 0,12% por um minuto, seguido da fricção das faces dentais com cotonete embebido na mesma sol...

  6. Encapsulamento da a-bixina em PHBV empregando tecnologia supercrítica e o controle de sua liberação in vitro

    OpenAIRE

    2013-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2013. O objetivo deste trabalho foi investigar a aplicação de dióxido de carbono pressurizado como anti-solvente para o encapsulamento da bixina em poli(hidroxibutirato-co-hidroxivalerato) (PHBV). Para os experimentos de encapsulamento, utilizou-se diclorometano como solvente orgânico e dióxido de carbono como antissolvente e uma câmara de pre...

  7. Experimental study of mechanisms of sand production using X-ray computerized tomography; Estudo experimental dos mecanismos da producao de areia empregando tomografia computadorizada de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Janaina B.; Vargas Junior, Euripedes [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil; Barroso, Emilio V. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Geologia; Campos, Elisabete; Goncalves, Clemente; Tavares, Andre [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    During productive phase of the well, many times there is simultaneous production of the solid particles detached from matrix of the reservoir rock. This phenomenon receives the name of the sand production. In this case stress and flow conditions around of the well are fundamental factors for deflagration of the process. Stress concentration in the wall of the well lead to the loss of cohesion between grains arising, consequently, a granular material region susceptible for dragging by seepage forces derived from fluid flow. The objective of this work was to perform sand production tests in Rio Bonito and synthetic sandstone samples using real-time X-Ray Computerized Tomography. The tests investigated the initial and the evolution of failure at the cavity wall of samples. These are initial stages of the sand production process. The analysis of the CT-scans obtained during tests allowed the visualization of breakouts and collapses of the wells. From studies more details were possible estimate the sand production and produce 3-D images of the propagation of the failure. (author)

  8. DETERMINAÇÃO DO TEOR DE BIODIESEL EM DIESEL EMPREGANDO O ENSAIO COLORIMÉTRICO DO ÁCIDO HIDROXÂMICO

    Directory of Open Access Journals (Sweden)

    Roberta P. M. da Costa

    2015-05-01

    Full Text Available The aim of this paper was to use colorimetric assays for hydroxamic acid to quantify the biodiesel content in diesel and compare it with the traditional method (infrared spectroscopy, using the EN 14078 method. Samples were prepared from B2 to B10 with two kinds of diesel - S500 (red and S50 (yellow - to obtain two calibration curves. Through statistical methods it was shown that the slopes of the straight lines obtained for the different types of diesel were the same. Thus, the type of diesel did not influence the results of the colorimetric assay for hydroxamic acid. Real samples collected from gas stations were analyzed by both methods (colorimetry and EN 14078. By applying Student's t-test it was concluded that the methods could be considered statistically equivalent. Therefore, it was confirmed that the colorimetric assay for hydroxamic acid is suitable for detecting and quantifying the content of biodiesel in biodiesel/diesel blends and can also be easily adapted to field analyses.

  9. Liberação de componentes do extrato de Casearia sylvestris Swartz empregando membranas de látex natural como suporte

    Directory of Open Access Journals (Sweden)

    Alberto Trecco

    2014-01-01

    Full Text Available A membrana de látex natural (NRL – Natural Rubber Latex, manipulada a partir do látex extraído da seringueira Hevea brasiliensis, tem apresentado grande potencial de aplicação no campo da biomedicina e dos biomateriais. Graças a sua biocompatibilidade e baixa taxa de rejeição, ela tem sido utilizada para próteses e enxertos, atuando como estimulante da angiogênese, adesão celular e barreira física a agentes infecciosos. Além dessas aplicações, as membranas são utilizadas como matriz de sistemas de liberação para avaliar o comportamento da liberação de fármacos e extratos de origem vegetal que apresentam propriedades medicinais. O sistema extrato-membrana tem como objeto de estudo uma nova abordagem dessas substâncias no tratamento de feridas visando à cicatrização e regeneração do tecido envolvido. Casearia sylvestris, conhecida popularmente como guaçatonga, pertence à família Salicaceae, conhecida na medicina popular pelos seus efeitos antiulcerogênicos, cicatrizantes, antiofídicos, anti-inflamatórios e antissépticos, propriedades já comprovadas por estudos. Trabalhos recentes demonstraram que a liberação controlada de fármacos e extratos utilizando membranas de látex natural é uma alternativa interessante e promissora para aplicações biomédicas. Assim, o objetivo deste projeto foi estudar a liberação do extrato de Casearia sylvestris incorporado à membrana de látex em soluções com diferentes valores de pH, com o propósito de estudar seu comportamento e sua liberação de forma controlada. A taxa de liberação do extrato do sistema extrato-membrana foi monitorada e analisada utilizando-se o método de espectroscopia ótica (UV. O pH básico age desestabilizando a membrana indicando que o polímero possui a habilidade de proteger o extrato de ser liberado em valores de pH ácidos, direcionando sua aplicação para o sítio de melhor absorção. Além disso, a liberação segue uma função bi-exponencial y(t=y0 +A1 e−t/τ1+A2 e−t/τ2, sendo que uma parte do extrato se encontra na superfície da membrana enquanto outra parte se encontra dentro da membrana (bulk. O extrato foi agregado à membrana e liberado por até 10 dias, sendo o pH=7,6 o que mais influenciou na liberação do extrato pela membrana. Este resultado é interessante, pois o pH da solução além de modificar o perfil de liberação, modifica o tempo de saturação tornando possível produzir uma membrana para cada aplicação, ou seja, uma membrana para o estômago, outra para a pele, e assim, por diante, pois cada órgão possui um pH característico.

  10. ANÁLISE DE TENSÕES EM ESTRUTURAS AXISSIMÉTRICAS EMPREGANDO A FORMULAÇÃO EM COORDENADAS POLARES DA TEORIA DE VOLUMES FINITOS

    OpenAIRE

    dos Santos, Arlan Ricardo C; Cavalcante, Márcio André A.

    2017-01-01

    Resumo. Este trabalho apresenta uma formulação para análise de tensões em estruturas axissimétricas, tais como tubos circulares, cilindros e anéis, elaborada com base em uma versão em coordenadas polares da Teoria de Volumes Finitos. Esta formulação é bastante apropriada para análise de tensões em estruturas com contornos curvos, apresentando geometria e campos mecânicos expressos em termo de coordenadas polares, visando melhorar o desempenho do método em tais situações. Diferentemente de ver...

  11. Simulação computacional de gaseificação de madeira de pequeno prte empregando um gaseificador downdraft

    OpenAIRE

    Boloy, Ronney Arismel Mancebo [UNESP

    2010-01-01

    Na atualidade, estão sendo desenvolvidas diversas tecnologia que aproveitam os recursos renováveis com a finalidade de gerar energia e diminuir emissão de poluentes ao meio ambiente. Entre essas tecnologia podemos citar a gaseificação, composta de métodos de conversão da biomassa em um gás combustível pobre. Nese caso, a biomassa deve ser gaseificada e condicionada para produzir gás de síntese que pode acionar um motor de combustão interna (MCI). A utilização do processo de gaseificação integ...

  12. Um novo procedimento de síntese da zeólita A empregando argilas naturais A new procedure for a zeolite synthesis from natural clays

    Directory of Open Access Journals (Sweden)

    Reus T. Rigo

    2009-01-01

    Full Text Available This work proposes the synthesis of zeolite A by IZA standard proceedures starting from a natural clay. The clay was used in its natural form and after calcination at 900ºC. The resulting materials were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and porosity analysis by nitrogen adsorption. Results showed low surface area for Na-A zeolite in sodium form, but a higher one in CaA based on the nitrogen accessibility. The presence of cubic crystals for the A phase was observed in the SEM micrographies. The new procedure starting from natural clay favors the formation of sodalite while that using the calcinated clay gives A.

  13. Síntese enzimática de butirato de isoamila empregando lipases microbianas comerciais Enzymatic synthesis isoamyl butyrate employing commercial microbial lipases

    Directory of Open Access Journals (Sweden)

    Vitor Cardoso Aragão

    2009-01-01

    Full Text Available Isoamyl butyrate production was investigated using free and immobilized lipases by esterification of butyric acid with isoamyl alcohol in a solvent-free system and in an organic media. Among the enzymes studied, Lipozyme TL IM was found to be the most active catalyst in n-hexane as a solvent. The effects of different solvents and the amount of water added on conversion rates were studied. A maximum conversion yield of 80% in n-hexano at 48 h was obtained under the following conditions: 3 g L-1 of Lipozyme TL IM, 30 ºC, 180 rpm of agitation, isoamyl alcohol to butyric acid molar ratio of 1:1 and acid substrate concentration of 0.06 M.

  14. Redução de alguns compostos carbonilicos derivados de fenil cetonas empregando-se fermento de pão (Saccharonyces cerevisiae)

    OpenAIRE

    Eugenia Cristina Souza Brenelli

    1994-01-01

    Resumo: Álcoois quirais são intermediários importantes na síntese de substâncias com atividade biológica, a saber, medicamentos, agroquímicos e feromônios. A redução assimétrica de cetonas proquirais por microorganismos, especialmente fermento de pão (Saccharomyces cerevisiae), é uma metodologia que tem se mostrado muito útil na obtenção de álcoois quirais em bons rendimentos químicos e ópticos. Neste trabalho estudou-se a redução assimétrica por fermento de pão de alguns compostos carbonílic...

  15. Bacteriemia após exodontia unitária, empregando dois métodos de anti-sepsia intrabucal

    Directory of Open Access Journals (Sweden)

    ROCHA BARROS Valdemar Mallet da

    2000-01-01

    Full Text Available O objetivo do trabalho foi avaliar a freqüência de bacteriemias pós-exodontia utilizando dois métodos de anti-sepsia pré-operatória, identificando os microrganismos isolados de hemoculturas pós-extração e avaliando a sua suscetibilidade a antibióticos. Vinte e seis pacientes tiveram 33 dentes extraídos. Dezesseis casos foram submetidos a anti-sepsia com bochecho com 15 ml de gluconato de clorexidina a 0,12% por um minuto, seguido da fricção das faces dentais com cotonete embebido na mesma solução (método 1 e 17 à anti-sepsia com dois bochechos com 15 ml de cloreto de cetilpiridínio a 1:4.000 por um minuto, intercalados pela fricção das faces dentais com peróxido de hidrogênio a 3,0% (método 2. Previamente à extração dental e cerca de 1 a 3 minutos após a mesma, colhiam-se 5,0 ml de sangue que eram semeados em meios de cultura e incubados por 20 dias. As cepas provenientes de hemoculturas positivas foram identificadas e submetidas ao antibiograma. Do total de casos, 68,8% apresentaram hemocultura positiva para o método 1 e 70,6% para o método 2. Houve maior prevalência de Actinomyces nos dois métodos, seguido de Streptococcus, Staphylococcus e Peptostreptococcus. O maior índice de resistência aos antibióticos testados esteve relacionado à oxacilina, enquanto não foi observada nenhuma cepa resistente à amoxicilina ou à cefalotina. Conclui-se que a freqüência de bacteriemia pós-exodontia foi elevada, independentemente do método de anti-sepsia empregado, prevalecendo microrganismos anaeróbios, os quais foram mais suscetíveis a amoxicilina e a cefalotina.

  16. Development of a method employing chitosan to remove metallic ions from wastewater; Desenvolvimento de um metodo empregando quitosana para remocao de ions metalicos de aguas residuarias

    Energy Technology Data Exchange (ETDEWEB)

    Janegitz, Bruno Campos; Lourencao, Bruna Claudia; Lupetti, Karina Omuro; Fatibello-Filho, Orlando [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2007-07-15

    In this work a method was developed for removing metallic ions from wastewaters by co-precipitation of Cu{sup 2+}, Pb{sup 2+}, Cd{sup 2+}, Cr{sup 3+} and Hg{sup 2+} with chitosan and sodium hydroxide solution. Solutions of these metallic ions in the range from 0.55 to 2160 mg L{sup -1} were added to chitosan dissolved in 0.05 mol L{sup -1} HCl. For the co-precipitation of metal-chitosan-hydroxide a 0.17 mol L{sup -1} NaOH solution was added until pH 8.5-9.5. A parallel study was carried out applying a 0.17 mol L{sup -1} NaOH solution to precipitate those metallic ions. Also, a chitosan solid phase column was used for removing those metallic ions from wastewaters. (author)

  17. Process of chemical recycling of post-consumer PET using a factorial design; Processo de reciclagem quimica do PET pos-consumo empregando o planejamento fatorial

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Carlos Eduardo de O.; Almeida, Yeda Medeiros B. de; Vinhas, Gloria M., E-mail: carlos.olacerda@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    The present study investigated important variables in the depolymerization reaction of post-consumer poly (ethylene terephthalate) - PET via alkaline hydrolysis. Through this reaction is obtained terephthalic acid (PTA), a monomer, which when purified, is used for the production of PET resin. The study was based on a 2{sup 2} factorial design in which the independent variables were the concentration of NaOH solution and the reaction time, and the dependent variable was the yield of PTA obtained. The experiments that generated the best results, 100 % of yield, were obtained with the higher values of the independent variables. Statistical analysis showed that the concentration of NaOH solution is the variable that most influences in the process. The PTA obtained was analyzed by NMR ¹H technique, confirming the strong resemblance to commercial PTA obtained by petrochemical way. (author)

  18. Teste de hemaglutinação na sorologia da malária humana empregando hemácias parasitadas pelo Plasmodium berghei

    Directory of Open Access Journals (Sweden)

    Maria Carmen Arroyo Sanchez-Ruiz

    1985-06-01

    Full Text Available Foi padronizado um teste de hemaglutinação para a sorologia da malária humana, com reagente constituído de suspensão de hemácias de camundongos infectadas pelo Plasmodium berghei e preservadas por fixação aldeídica. Em pacientes com parasitemia por P. falciparum ou P. vivax obteve-se uma sensibilidade de 98,9% nos 88 casos estudados, o teste apresentando títulos entre 40 e 640. Para o grupo de 476 soros de indivíduos não-maláricos, obteve-se uma especificidade de 96,0%. O teste apresentou elevada reprodutibilidade, mesmo para diferentes lotes de antígenos. Nos 200 soros, obtidos ao acaso, de indivíduos de área endêmica, o teste apresentou positividade de 48,5%, contra 88,0% do teste de imunofluorescência-IgG. A baixa positividade pode ser devida a que o teste de hemaglutinação detecta anticorpos IgM. Após tratamento com 2-mercaptoetanol, todos os soros de pacientes com parasitemia tornaram-se não reagentes. Em relação ao teste de imunofluorescência-IgG, o teste de hemaglutinação apresentou índice de co-positívidade de 0,989 para os soros de maláricos com parasitemia. Para os soros de não-maláricos o teste de hemaglutinação apresentou índice de co-negatividade de 0,969. Por outro lado, no grupo de soros de área endêmica, o índice de co-positividade foi de 0,528 e o de co-negatividade, de 0,833.A hemagglutination test is described for human malaria serodiagnosis with aldehyde-fixed Plasmodium berghei infected mouse erythrocytes. In patients with a P. falciparum or P. vivax patent parasitemia positive results were seen in 98.9% ofthe 88 cases tested. Titres rangedfrom 40 to 640. A 96.0% specificity wasfoundfor 476 non-malarialpatients. A close reproducibility was observed forthe test, even for dijferent reagent batches. The test was positive in 48.5% of 200 residents in malaria endemic areas, taken at random. These subjects showed 88.0% positivity of the IgG-immunofluorescence test. This lower positivity for the hemagglutination test could result from its reactivity with IgM antibodies. After 2-mercaptoethanol treatment, all serafrom patients with patent parasitemia were non-reactive. The hemagglutination test, with reference to the IgG-immunofluorescence test, showed a 0.989 co-positivity for patients with a patent parasitemia and a 0.969 co- negativity for non-malarialpatients. For residents in endemic areas a co-positivity of 0.528 and a co- negativity of0.833 were observed.

  19. Estudos dos efeitos do ultra-som na determinação e degradação de pesticidas e seus subprodutos empregando eletrodos de diamante

    OpenAIRE

    Gustavo Stoppa Garbellini

    2009-01-01

    O desenvolvimento de metodologias eletroanalíticas altamente eficientes para a determinação de resíduos de pesticidas em amostras de alimentos usando a radiação de ultra-som (US) e o eletrodo de diamante dopado com boro (DDB) é reportado neste trabalho.Também são apresentadas tentativas para melhorar a degradação eletroquímica de pesticidas e de seus metabólitos no ambiente usando estas novas ferramentas (US e DDB) para minimizar o bloqueio da superfície eletródica que, usualmente, impede ...

  20. Hydrogen purification for fuel cell by copper promoted gold catalysts; Purificacao de hidrogenio para pilha a combustivel utilizando catalisadores de ouro promovidos com cobre

    Energy Technology Data Exchange (ETDEWEB)

    Mozer, Thiago S.; Vieira, Carlos T.P.; Passos, Fabio B. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Dziuba, Dominika A. [Hochschule Mannheim (Germany)

    2008-07-01

    Copper promoted gold catalysts were studied for hydrogen purification through selective CO oxidation. The Cu acted as a selectivity promoter favoring the CO conversion and decreasing the H{sub 2} consumption. The deposition-precipitation method, used to prepare the samples generated small and well dispersed gold particles, as the UV-vis DRS spectra did not show the 'plasmon' band, which indicates that the samples are active for SELOX. The activity tests showed high CO conversion, the bimetallic 2,5%Au-0,5%Cu/Al{sub 2}O{sub 3} catalyst showed the best behavior in the tested condition, 95% of CO conversion and 75% of selectivity at 50 deg C. Increasing the O{sub 2} content in the feedstream the CO conversion also increased, although the selectivity decreased. (author)

  1. Thermal insulation field replacement for operating high temperature oil; Substituicao in situ do revestimento isolante termico de dutos que transportam oleo combustivel aquecido, sem paralisacao operacional

    Energy Technology Data Exchange (ETDEWEB)

    Maniero, Leo [Transpavi-Codrasa S.A., Sao Paulo, SP (Brazil); Oliver, Joao H. de L.; Pinto, Mucio E.A. C. [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The in Situ rehabilitation of the thermal isolated coating of heated pipelines required a technology development for material and equipment innovation, in such way, the coating rehabilitation was conducted keeping the continuous pipeline operation at 85 deg C. The new thermal coating is applied after the following services stages: dig the trench, purge the old thermal insulation, sand blasting of the steel pipe, application of a anticorrosive coating in the metallic substratum for continuous operation at 120 deg C, application of spacers around the steel pipe, fabrication of a polyethylene (PE) casing, cut and opening of the PE casing in its own longitudinal line, setting the PE casing over the spacers, closing of the PE casing by longitudinal thermoplastic welding with the automatic machine, boring a opening in the PE casing sidelong, injection of polyurethane foam inside of the PE casing, tampon the bores by thermoplastic weld, tying-in the PE casing with the next contiguous casing with electro fusion weld. The casing-bends are made from the PE casing cut in angles, like the specific project of each bend, the casing-bends are mounted outer the steel pipeline bends follows the same sequences of stages. (author)

  2. Analysis of cogeneration system using fuel cell: cases study; Analise de sistema de cogeracao utilizando celula de combustivel: estudo de casos

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Jose Luz; Leal, Elisangela Martins [UNESP, Guaratingueta, SP (Brazil). Escola de Engenharia. Dept. de Energia]. E-mails: joseluz@feg.unesp.br; elisange@feg.unesp.br

    2000-07-01

    In this paper, a methodology for the study of a molten carbonate fuel cell cogeneration system associated to an absorption refrigeration system, for the electricity and cold water production, and applied to two establishments, is presented. This system permits the recovery of waste heat, available between 600 deg C e 700 deg C. Initially, some technical information about the most diffusing types of the fuel cell demonstration in the world are presented. In the next step, an energetic, exergetic and economic analysis are carry out, seeking the use of fuel cells, in conditions of prices and interest of Brazil. In conclusion, the fuel cell cogeneration system may have an excellent opportunity to strengthen the decentralized energy production in the Brazilian energy scene. (author)

  3. Peg-methacrylate and styrene copolymers as an electrolyte for fuel cell application; Copolimeros de peg-metacrilato e estireno para aplicacao como eletrolito em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Groetzner, Mariana B.; Ferraz, Fernando A.; Rodrigues, Maraiza F.; Oliveira, Angelo R.S.; Barbosa, Ronilson V.

    2005-07-01

    Researches have demonstrated that Polymer Ion Exchange Membranes, applied in low temperature fuel cells, have high water absorption and also high ionic conductivity. The poly(ethylene glycol) 4000 - PEG - transesterification reactions, with methyl methacrylate (MMA) under acid catalysis, has generated a modified ester (PEGMMA), which has been reacted with styrene, under specific conditions, giving a copolymer (PEGMMAS). In order to obtain a final product with proton conduction characteristics, it is necessary to sulfonate it. The results have showed that the product obtained have, not only good hidrofilicity, but also potential structure for an easy sulfonation procedure for further studies in fuel cell application. (author)

  4. Technological study of experimental proton exchange polymer membrane fuel cells; Estudo tecnologico de celulas a combustivel experimentais a membrana polimerica trocadora de protons

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Thais Aranha de Barros

    2004-07-01

    Experimental studies to achieve an optimized behavior of a unit PEM-fuel cell with an active area of 25cm{sup 2} were carried out. Polarization curves, surface response methodology and regression methodology were used for the analysis. The different methodologies identified the interactions between the parameters that were studied. These parameters were, humidifying temperature, fuel cell operating temperature and the flows of hydrogen and oxygen. MEAs were produced by the spray and hot pressing hybrid method, developed at IPEN. The studies were done with these MEAs and equivalent commercial ones. The MEAs producing method used induced an important variation on the quantity of platinum in the electrodes. This fact has showed to have a great influence in the results. The optimized values were: oxygen flow from 30 to 35% of consume (70 to 65% of excess), fuel cell operating temperature from 60 to 62 deg C and 0.41 mg of platinum in the electrodes. The hydrogen flows and the humidifying temperature have not showed a major influence in the fuel cell behavior, in the studied variable range. (author)

  5. Performance of a diesel engine transformed to spark ignition using natural gas; Desempenho de um motor diesel convertido para utilizacao de gas natural como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Ricardo H.R. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LEDAV/COPPE/UFRJ), RJ (Brazil). Lab. de Ensaios Dinamicos e Analise de Vibracao; Belchior, Carlos R.P. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LMT/COPPE/UFRJ), RJ (Brazil). Lab. de Maquinas Termicas; Sodre, Jose Ricardo [Pontificia Universidade Catolica de Minas Gerais (PUC/Minas), MG (Brazil)

    2012-07-01

    A zero-dimensional thermodynamic model for a diesel engine converted for dedicated use of natural gas was developed in this work. The computational model covers from the time of closing the inlet valve to the time of opening the exhaust valve and it was divided into three stages (compression, combustion and expansion). A model based on the first law of thermodynamics for closed cycle has been developed to study the performance of the engine. The combustion process was modeled using the equation of Wiebe. It was taken into consideration the convective heat transfer through the walls of the cylinder and the heat transfer coefficient was calculated by the Eichelberg correlation. It was also considered that the thermodynamic properties vary with temperature. To represent the gas mixture behavior inside the cylinder two approaches (Ideal Gas Equation and Van Der Waals's Real Gas Equation) were used and results compared. The computational model was validated with experimental tests. (author)

  6. Hydrogen purification for fuel cells using gold catalysts promoted with copper; Purificacao de hidrogenio para celulas a combustivel utilizando catalisadores de ouro promovidos com cobre

    Energy Technology Data Exchange (ETDEWEB)

    Mozer, Thiago Simonato; Passos, Fabio Barboza [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Quimica e de Petroleo. Lab. de Reatores, Cinetica e Catalise (RECAT)]. E-mail: mozer@vm.uff.br

    2008-07-01

    The selective CO oxidation in the presence of H2 was investigated on Au catalysts promoted with different amounts of Cu. Au catalysts were prepared by the deposition-precipitation method and exhibited a satisfactory activity at 50 deg C with adequate selectivity. The addition of Cu to Au/Al{sub 2}O{sub 3} catalysts caused an increase in the selectivity to CO oxidation due to an interaction between Au and Cu on the surface of the catalysts. However, this beneficial effect was limited to an optimal content of Cu. Through the temperature programmed reduction (TPR) and ultraviolet visible diffuse reflectance spectroscopy (UV-vis DRS) techniques, the formation of small bimetallic Au-Cu particles was verified. The best result was obtained with 2.5% Au-0.5% Cu/Al{sub 2}O{sub 3} catalyst, the CO conversion was higher than 95% and the selectivity was around 70% at 50 deg C. The catalysts showed stable catalytic activity during 24 hours time -on-stream. In the presence of H{sub 2}O and CO{sub 2}, a small decrease in the CO conversion was observed in the stability test, probably due to the deactivation caused by the CO{sub 2} presence. (author)

  7. Fuel cells using ionic liquids as electrolyte and operating at room temperature; Celulas de combustivel utilizando como eletrolito liquidos ionicos e operando a temperatura ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Botton, Janine Padilha; Souza, Roberto Fernando de; Goncalves, Reinaldo Simoes; Dupont, Jairton [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica], e-mail: janine@iq.ufrgs.br

    2004-07-01

    The room temperature imidazolium based ionic liquids, such as 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) are outstanding electrolytes for fuel cells. A 67% overall cell efficiency is achieve using these liquids as supporting electrolytes for a commercially available alkaline fuel cell (AFC) at room temperature operating with air and hydrogen at atmospheric pressure. (author)

  8. Cogeneration, micro turbines and fuel cells: perspectives for distributed generation in Brazil; Cogeracao, microturbinas e celulas a combustivel: perspectivas para geracao distribuida no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Marco Antonio Haikal [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    Brazil has a large potential to install distributed generation systems, using natural gas or renewable like solar, wind or biomass energy. Regarding urban centers, natural gas fired cogeneration and other distributed energy technologies find economical applications. Cogeneration is defined as the generation of two kinds of useful energy from a single energy source. Usually, electrical energy and thermal energy as steam or hot water are produced. By using the absorption refrigeration cycle, chilled water can also be produced to be used in air conditioned systems, often called tri generation, a good alternative to industries, commercial buildings, shopping centers, hospitals, schools and universities. Micro turbines find utilization whenever natural gas is available, but not electricity, like gas compression installations, unmanned platforms or remote production fields. Fuel cells are used in systems requiring high levels of reliability or wherever the non availability cost is high. This paper describe technical and economical data related to PETROBRAS Research Center (CENPES) 3,200 kW electric energy and 1,000 RT chilled water cogeneration system, 200 kW fuel cell and 30 kW and 60 kW microturbines. (author)

  9. Implementation of a photovoltaic/electrolyzer/fuel cell autonomous system; Implementacao de um sistema autonomo fotovoltaico/eletrolisador/celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ennio Peres da; Apolinario, Fernando Rezende; Furlan, Andre Luis [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio], Emails: lh2ennio@ifi.unicamp.br, rezende@ifi.unicamp.br; Souza, Rubem Cesar Rodrigues [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Centro de Desenvolvimento Energetico Amazonico], Email: rubem_souza@yahoo.com.br; Pinto, Adailton de Souza [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Brasilia, DF (Brazil)], Email: adailton@eln.gov.br

    2006-07-01

    This article presents a project whose main objective is to analyze the technical feasibility of using a system based on the production of hydrogen (H{sub 2}) for storing the energy generated for photovoltaic systems. The work involves the design, physical implementation and the performance evaluation of a system for hydrogen electrolytic generation with solar-photovoltaic energy, the treatment os gas, its storage and it use in fuel cell systems. This work will be performed in cooperation between researchers from the Laboratorio de Hidrogenio (LH2) of the UNICAMP and of the Centro de Desenvolvimento Energetico Amazonico (CDEAM) of the UFAM, and is financing by ELETRONORTE.

  10. Development of perovskite cathodes for solid oxide fuel cells (SOFC); Desenvolvimento de catodos de perovskitas para celula a combustivel solido de eletrolito solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica], e-mail: joelma@iq.unesp.br; Pereira, J.T.; Saeki, M.J. [UNESP, Bauru, SP (Brazil). Faculdade de Ciencias

    2006-07-01

    Solid Oxide Fuel Cells (SOFC) are energy conversion systems of great interest for industrial applications because they present a high efficiency for energy generation and several advantages for the environment. In this work, perovskite type oxides La{sub 085}Sr{sub 0,15}MnO{sub 3}, La{sub 0,7} Sr{sub 0,3}MnO{sub 3}, La{sub 0,6}Sr{sub 0,4}MnO{sub 3}, La{sub 0,85}Sr{sub 0,15}CoO{sub 3}, La{sub 0,7}Sr{sub 0,3}CoO{sub 3}, La{sub 0,6}Sr{sub 0,4}CoO{sub 3}, La{sub 0.6}Sr{sub 0,4}Fe{sub 0,8}Co{sub 0,2}O{sub 3} e La{sub 0.6}Sr{sub 0,4}Fe{sub 0,4}Co{sub 0,6}O{sub 3} were prepared by a polymeric method with the purpose of using them as cathodes in SOFCs. The electrochemical cell was mounted utilizing YSZ (ZrO{sub 2} - 8 mol%Y{sub 2}O{sub 3}) disks as electrolyte, where a paste containing Pt was calcined onto one face while the other one was covered with the oxide materials synthesized ('screen printing'). The oxide materials prepared were characterized by X-ray diffraction, transmission electronic microscopy and thermogravimetry. The oxygen reduction reaction was studied by taking polarization curves in oxygen and/or air (800 deg C a 950 deg C). The best performance was obtained for 15 {mu}m thickness electrodes La{sub 0.6}Sr{sub 0,4}MnO{sub 3} and La{sub 0.6}Sr{sub 0,4}MnO{sub 3} with addition of dispersed Pt. (author)

  11. Biomass gasification and fuel cells: system with PEM fuel cell; Gaseificacao de biomassa e celula a combustivel: sistema com celula tipo PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Sordi, Alexandre; Lobkov, Dmitri D.; Lopes, Daniel Gabriel; Rodrigues, Jean Robert Pereira [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica], e-mail: asordi@fem.unicamp.br, e-mail: lobkov@fem.unicamp.br, e-mail: danielg@fem.unicamp.br, e-mail: jrobert@fem.unicamp.br; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin], e-mail: Lh2ennio@ifi.unicamp.br

    2006-07-01

    The objective of this paper is to present the operation flow diagram of an electricity generation system based on the biomass integrated gasification fuel cell of the type PEMFC (Proton Exchange Membrane Fuel Cell). The integration between the gasification and a fuel cell of this type consists of the gas methane (CH4) reforming contained in the synthesis gas, the conversion of the carbon monoxide (CO), and the cleaning of the gaseous flow through a PSA (Pressure Swing Adsorption) system. A preliminary analysis was carried out to estimate the efficiency of the system with and without methane gas reforming. The performance was also analyzed for different gasification gas compositions, for larger molar fractions of hydrogen and methane. The system electrical efficiency was 29% respective to the lower heating value of the gasification gas. The larger the molar fraction of hydrogen at the shift reactor exit, the better the PSA exergetic performance. Comparative analysis with small gas turbines exhibited the superiority of the PEMFC system. (author)

  12. Modelling and essay or the polarization curve of a polymeric membrane fuel cell; Modelagem e ensaio da curva de polarizacao de uma celula a combustivel de membrana polimerica

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Silvio Carlos Anibal de; Xavier, Bruno Domont; Gatti, George Cassani; Ribeiro, Rodrigo Minguita [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Mecanica]. E-mails: silvioa@gmail.com; brunodomont@gmail.com; gatti_ufrj@yahoo.com.br; rminguita@yahoo.com.br; Furtado, Jose Geraldo de Melo [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil). Dept. de Tecnologias Especiais]. E-mail: furtado@cepel.br

    2006-07-01

    This paper describes the essays performed with a polymeric membrane fuel cell (PEMFC) at the test laboratories of the ELETROBRAS Electric Energy Research Center (CEPEL/ELETROBRAS) manufactured by the Eletrocell, which allows to study the influence of some functional parameters (voltage, current, mass and pressure fluxes)

  13. Synthesis, characterization and electrical properties of solid electrolyte for solid oxide fuel cell; Preparacao, caracterizacao e propriedades eletricas de eletrolito solido para celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Marco Antonio Coelho; Garcia, Carlos Mario; Matos, Jeferson Hrenechen [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: felsky@latec.org.br, garcia@latec.org.br, jeferson.h@latec.org.br

    2010-04-15

    Solid electrolytes of BaCe{sub 08}Gd{sub O29} were prepared by the polymeric precursor method. X-ray diffraction data shows a single phase with orthorhombic crystalline structure. The densification process was followed by scanning electronic microscopy and apparent density measurements. The apparent density was developed for different temperatures of sintering, reaching > 96% for sintered temperature of 1550 {sup 0}C deg . The electrochemical impedance analysis was development in the temperature of 400-700 deg C, in air atmosphere at 700 deg C a value of 30,6 mS.cm{sup -1} was obtained. The results of conductivity have confirmed the gadolinium doped barium cerate has a great potential for use as solid electrolyte for intermediate temperature solid oxide fuel cell, at experimental controlled conditions. (author)

  14. Wind, photovoltaic and fuel cell energy for communication stations; Energia eolica, fotovoltaica e de celula a combustivel para estacoes de comunicacao

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Iolanda; Pereira, Jose; Alcobia, Hernani [Net Plan Telecomunicacoes e Energia, Lisboa (Portugal); Pereirinha, Paulo [Instituto Politecnico de Coimbra (Portugal); Instituto para Engenharia de Sistemas e Computadores de Coimbra (Portugal)

    2011-10-15

    This paper presents a hybrid system that provides power to a remote and autonomously telecommunications station by means of electrical solar generators, wind and hydrogen fuel cell. In the absence of sufficient sun and wind, a bank of batteries and hydrogen produced on-site guarantee the power supply. The station can still be remote monitored and managed.

  15. Evaluation of plate type fuel options for small power reactors; Avaliacao de alternativas de combustivel tipo placa para reatores de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Andrzejewski, Claudio de Sa

    2005-07-01

    Plate type fuels are generally used in research reactor. The utilization of this kind of configuration improves significantly the overall performance fuel. The conception of new fuels for small power reactors based in plate-type configuration needs a complete review of the safety criteria originally used to conduce power and research reactor projects. In this work, a group of safety criteria is established for the utilization of plate-type fuels in small power reactors taking into consideration the characteristics of power and research reactors. The performance characteristics of fuel elements are strongly supported by its materials properties and the adopted configuration for its fissile particles. The present work makes an orientated bibliographic investigation searching the best material properties (structural materials and fuel compounds) related to the performance fuel. Looking for good parafermionic characteristics and manufacturing exequibility associated to existing facilities in national research centres, this work proposes several alternatives of plate type fuels, considering its utilization in small power reactors: dispersions of UO{sub 2} in stainless steel, of UO{sub 2} in zircaloy, and of U-Mo alloy in zircaloy, and monolithic plates of U-Mo cladded with zircaloy. Given the strong dependency of radiation damage with temperature increase, the safety criteria related to heat transfer were verified for all the alternatives, namely the DNBR; coolant temperature lower than saturation temperature; peak meat temperature to avoid swelling; peak fuel temperature to avoid meat-matrix reaction. It was found that all alternatives meet the safety criteria including the 0.5 mm monolithic U-Mo plate cladded with zircaloy. (author)

  16. Polyester synthesis for application in PEMFC type fuel cells; Sintese de poliester para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.P.; Souza, D.R. de; Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica], e-mail: raigenis@gmail.com

    2006-07-01

    The PEMFC (Proton Exchange Membrane Fuel Cell), along the SOFC (Solid Oxide Fuel Cell), is the most important technology, among the various types of fuels cell. The PEMFC shows a large versatility of applications, both for stationary and mobile use. However the PEMFC presents high manufacture cost, directly impacting in the cost of the produced energy. This work contemplates the previews sulfonation of phtalic acid and its subsequent polymerization with glycerol, using as catalytic tin dibutyl-dilaurate. The obtained material has been characterized by DSC, TGA, FTIR, MEV, DRX and XRF. The gotten results indicated that phtalic acid was sulfonated and the increase of the sulfonation degree significantly increased the crystallinity of the sulfonated ftalico acid. Furthermore, the polymer produced from the sulfonated monomer presented adequate thermal resistance and a high content of conducting groups, necessary conditions for application as electrolyte in PEMFC. All these characteristics, particularly the low cost of the reagents and the ease of production process, make the sulfonated polyester membrane a promising candidate as fuel cell electrolyte. (author)

  17. Study for application of multi fuel technology in the Brazilian automobilistic market; Estudo para aplicacao da tecnologia multi combustivel no mercado automobilistico brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Gasparotto, Alexsander David [FIAT/GM Powertrain (Brazil); Massarani, Marcelo [Universidade de Sao Paulo (USP), SP (Brazil)

    2006-07-01

    The objective of this work is a study for the application of a new technology that will be used in the engine management system in the vehicle; where the final consumer can opt for the inquiry performance or seeking an economy for the fuel consumption depending on its daily use and of the prices offered in the gas stations. Flexible Fuel is a technology in development for the automobile market that mixes the use of two fuels (gasoline and ethanol) and their mixtures in the internal combustion engine. (author)

  18. Preparation of PVDF and PTFE membranes for fuel cell use; Preparacao de membranas de PVDF e PTFE enxertadas e sulfonadas para uso em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Adriana N.; Zen, Heloisa A.; Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: angeral@ipen.br

    2007-07-01

    Grafting of styrene onto polyvinylidenefluoride (PVDF), polytetrafluoroethylene (PTFE) was studied using styrene/toluene solutions. First, PTFE and PVDF films were prepared and the process was conducted by radiation induced graft polymerization of styrene, by a Co{sup 60} source. Films of PTFE and PVDF were immersed in styrene/toluene at 1:1 (v/v) concentration and then submitted to gamma radiation at 20 kGy doses. After irradiation, the samples were evaluated at the period of 21 days at room temperature in order to observe the grafting degree. Chemical changes in the PVDF and PTFE films after styrene grafting were monitored and the results were evaluated by FTIR, DSC, TGA and degree of grafting (DOG). The ion exchange capacity (IEC) after sulfonation of 1, 2 and 24 hours were also determined. (author)

  19. Technological evaluation of fuel cells using natural gas for distributed power generation; Avaliacao tecnologica da utilizacao de gas natural em celulas a combustivel para geracao distribuida de energia

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Mauricio O. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Engenharia Mecanica; Giannini, Marcio P.; Arouca, Mauricio C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

    2004-07-01

    The search for sustainable and more rational means of power generation motivates the scientific crew to search for more efficient and cleaner systems. Oil dependence becomes from the kind of development that the humanity had and cannot be dismissed. The question is how to use this source in a more intelligent way. Fuel Cells are electrochemical devices that convert into electric energy the chemical energy from oxi-reduction reactions between a fuel and an oxidant. The current fuel used in a Fuel Cell is hydrogen and oxygen is the oxidant. The great advantage of this device is its efficiency, higher than the one achieved with internal combustion engines. Also Fuel Cells are not limited by Carnot's efficiency. This paper is about the implementation of a distributed generation system using Fuel Cells. Technical aspects are approached together with economical and environmental needs. The already existence of Gas pipelines and the grown production of Natural Gas presented by Brazil turns it into a good market for the implementation of this energy source. The evaluation of this paper shows that is technically possible to use NG in Fuel Cells, mostly in South and Southeast regions, applying the distributed generation of energy concept. The most interesting in a strategic manner is that Brazil already have an indication that it's capable of developing this technology, opening a new market tuning with world's new technological developments. Many research centers develop this technology, not only from the cell composition itself, but also manufacturing techniques. (author)

  20. A study on domino effect in nuclear fuel cycle facilities; Um estudo sobre o efeito domino em instalacoes do ciclo do combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Bozzolan, Jean-Claude

    2006-07-01

    Accidents caused by domino effect are among the most severe accidents in the chemical and process industry. Although the destructive potential of these accidental scenarios is widely known, little attention has been paid to this problem in the technical literature and a complete methodology for quantitative assessment of domino accidents contribution to industrial risk is still lacking. The present study proposed a systematic procedure for the quantitative assessment of the risk caused by domino effect in chemical plants that are part of nuclear fuel cycle plants. This work is based on recent advances in the modeling of fire and explosion damage to process equipment due to different escalation vectors (heat radiation, overpressure and fragment projection). Available data from literature and specific vulnerability models derived for several categories of process equipment had been used in the present work. The proposed procedure is applied to a typical storage area of a reconversion plant situated in a complex that shelters other nuclear fuel cycle facilities. The top-events and escalation vectors are identified, their consequences estimated and credible domino scenarios selected on the basis of their frequencies. (author)

  1. Characterization and improvement gas diffusion layer of low temperature fuel cell; Caracterizacao e aprimoramento da camada difusora de celulas a combustivel de funcionamento a baixa temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, C.Z.; Dantas, R.; Oliveira, I.S. de; Azevedo, C.M.N.; Pires, M. [Pontificia Univ. Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Quimica; Canalli, V. [Pontificia Univ. Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Faculdade de Engenharia

    2006-07-01

    In low temperature fuel cells the main part is the membrane electrode assembly (MEA). The gas diffusion layer is a component of the MEA, being a composite material constituted by carbon powder and polytetrafluoroethylene, used to increases hydrofobicity, fundamental characteristic in water transport into system. In this work methods were adapted with the aim to a better characterization of the diffusion layer by the measuring the following parameter: contact angle and hysteresis; morphology, thickness and porosity. From these characterization results optimized MEAS will be produced to better fuel cell performance. (author)

  2. Interpenetrating polymer network membranes for fuel cells: infrared vibrational spectroscopy; Membranes baseadas dm redes polimericas interpenetrantes para celulas a combustivel: estudo por espectroscopia vibracional no infravermelho

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Felipe A.M.; Rocco, Ana Maria [Grupo de Materiais Condutores e Energia, Escola de Quimica, Universidade Federal do Rio de Janeiro, RJ (Brazil)], e-mail: amrocco@eq.ufrj.br; Pereira, Robson Pacheco [Instituto de Ciencias Exatas, Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil)

    2011-07-01

    In the present work, proton conductive membranes based on IPN matrices doped with H{sub 3}PO{sub 4} were developed. The characterization by infrared vibrational spectroscopy evidenced the polymerization of DGEBA and the immobilization of PEI chains, originating a structure containing basic sites suitable for proton coordination and conduction. The FTIR characterization evidenced the polymerization of DGEBA in the presence of PEI thus forming Semi-IPN membranes which, after doped with H{sub 3}PO{sub 4}, exhibited conductivity values of 10{sup -4} W{sup -1}cm{sup -1} at room temperature and 10{sup -3} {omega}{sup -1}cm{sup -1} at 80 degree C, as well as a dependency of conductivity with temperature following the Arrhenius model. The activation energy values (14,33 and 12,96 kJ.mol{sup -1}) indicated a proton conduction mechanism predominantly vehicular in the matrices studied under 100% relative humidity. (author)

  3. Fluid dynamic simulation of the fluidized bed using propane-air fuel; Simulacao dinamica de um combustor de leito fluidizado utilizando como combustivel o ar-propanado

    Energy Technology Data Exchange (ETDEWEB)

    Lima Junior, L.P.; Lucena, S.; Silva, D.J. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Quimica]. E-mail: limajun@br.inter.net

    2004-07-01

    This paper has for purpose to present the modeling and simulation of the homogeneous combustion of the mixture of propane-air in a combustor of fluidized bed with inert particles, basing on a stationary model with phases in series, being taken into account the thermal changes and mass changes among the phases and it changes thermal with the wall for radiation. Computational methods are used for such simulation and CFX 4.4 as dynamic flowing computation software (CFD), kindred of more proximity with the real aspects. Being studied like this dynamic and kinetic flowing parameters of the involved components. (author)

  4. Seasonal variation of prices of sugar cane, ethanol and electric power; Variacao estacional dos precos da cana-de-acucar, alcool combustivel e energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Carmem Ozana de; Silva, Gerson Henrique da; Bueno, Osmar de Carvalho [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil); Esperancini, Maura Seiko Tsutsui [Universidade Estadual do Oeste do Parana (UNIOESTE), Francisco Beltrao, PR (Brazil)

    2010-07-01

    The aim of this study was to assess the seasonal price of sugar cane, fuel alcohol (hydrated and anhydrous) and electricity tariffs as a way of aiding tool for optimization of energy generation, using biomass originating from cane sugar. Using the method of moving average centered was concluded that cane and electricity rates were close to seasonal average, with low range of prices, suggesting the non-occurrence of seasonal variation in prices. Unlike the seasonal indices of ethanol showed seasonal variation of prices with greater amplitude of seasonal index. Thus, the results suggest that the utilization of by-products of sugar cane to produce electrical power points to the prospect of reducing risks associated with variations in the price of ethanol, thereby contributing to greater stability and possibility to those involved in planning alcohol sector. (author)

  5. Sensitivity analysis for heat diffusion in a fin on a nuclear fuel element; Analise de sensitividade na difusao de calor em uma aleta de um elemento combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Tito, Max Werner de Carvalho

    2001-11-15

    The modern thermal systems generally present a growing complexity, as is in the case of nuclear power plants. It seems that is necessary the use of complex computation and mathematical tools in order to increase the efficiency of the operations, reduce costs and maximize profits while maintaining the integrity of its components. The use of sensitivity calculations plays an important role in this process providing relevant information regarding the resultant influence of variation or perturbation of its parameters as the system works. This technique is better known as sensitivity analysis and through its use makes possible the understanding of the effects of the parameters, which are fundamental for the project preparation, and for the development of preventive and corrective handling measurements of many pieces of equipment of modern engineering. The sensitivity calculation methodology is based generally on the response surface technique (graphic description of the functions of interest based in the results obtained from the system parameter variation). This method presents a lot of disadvantages and sometimes is even impracticable since many parameters can cause alterations or perturbations to the system and the model to analyse it can be very complex as well. The utilization of perturbative methods result appropriate as a practical solution to this problem especially in the presence of complex equations. Also it reduces the resultant computational calculus time considerably. The use of these methods becomes an essential tool to simplify the sensitivity analysis. In this dissertation, the differential perturbative method is applied in a heat conduction problem within a thermal system, made up of a one-dimensional circumferential fin on a nuclear fuel element. The fins are used to extend the thermal surfaces where convection occurs; thus increasing the heat transfer to many thermal pieces of equipment in order to obtain better results. The finned claddings are projected to gas-cooled nuclear reactors to compensate the low coolant thermal transport efficiency. The model is described by the temperature distribution equation and the further specific boundary conditions. The adjoint system is used to determine the sensitivity coefficients to the case of interest. Both, the direct model and the perturbative formalism resultant equations are solved. The heat flow rate on a point of the fin and the average temperature excess were the response functionals studied. The half thickness, the thermal conductivity and heat transfer coefficients and the heat flow from the base material were the parameters of interest to the sensitivity analysis. The results obtained through the perturbative method and the direct variation presented, in a general form and within acceptable physical limits, good concordance and excellent representativeness to the analyzed cases. It evidences that the differential formalism is an important tool to the sensitivity analysis and also it validates the application of the methodology in heat transmission problems on extended surfaces. The method proves to be necessary and efficient while elaborating thermal engineering projects. (author)

  6. Seasonal variation of prices of sugar cane, ethanol and electric power; Variacao estacional dos precos da cana-de-acucar, alcool combustivel e energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Carmem Ozana de; Silva, Gerson Henrique da; Bueno, Osmar de Carvalho [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil); Esperancini, Maura Seiko Tsutsui [Universidade Estadual do Oeste do Parana (UNIOESTE), Francisco Beltrao, PR (Brazil)

    2010-07-01

    The aim of this study was to assess the seasonal price of sugar cane, fuel alcohol (hydrated and anhydrous) and electricity tariffs as a way of aiding tool for optimization of energy generation, using biomass originating from cane sugar. Using the method of moving average centered was concluded that cane and electricity rates were close to seasonal average, with low range of prices, suggesting the non-occurrence of seasonal variation in prices. Unlike the seasonal indices of ethanol showed seasonal variation of prices with greater amplitude of seasonal index. Thus, the results suggest that the utilization of by-products of sugar cane to produce electrical power points to the prospect of reducing risks associated with variations in the price of ethanol, thereby contributing to greater stability and possibility to those involved in planning alcohol sector. (author)

  7. Conductor polymeric membranes with potential for application in PEM type fuel cells; Membranas polimericas condutoras com potencialidades para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Brioude, Michel de Meireles; Sodre, Livia Farias; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)

    2006-07-01

    In this work two series of membranes were prepared; they were based on hybrid organic-inorganic or composite materials and presented potentiality for application in Proton Exchange Membrane Fuel Cell, PEMFC. The polymeric phase was constituted of poly(dimethylsiloxane), PDMS, crosslinked with tetra ethoxysilane, TEOS, with a 70%/30% ratio. Phosphotungstic acid (PWA) or the sodium monododecylsulphate (MDS), as proton conductors, were added to the inorganic network, close to the gel point; the mixtures were transferred to a cast. The films were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The membranes showed good properties, as flexibility, thermal and mechanical stability with potentiality to be used as conducting membranes in technological applications. (author)

  8. Certification for copper concentration in reference material for fuel anhydro ethylic alcohol; Certificacao da concentracao de cobre em material de referencia para alcool etilico anidro combustivel (AEC)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lindomar Augusto dos; Rocha, Marcia Silva da; Mesko, Marcia Foster; Silva, Fagner Francisco da; Quaresma, Maria Cristina Baptista; Araujo, Thiago Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (DIMCI/INMETRO), Duque de Caxias, RJ (Brazil). Diretoria de Metrologia Cientifica e Industrial], E-mail: lareis@inmetro.gov.br

    2009-07-01

    This work aiming to obtain the first certified reference material for fuel anhydro ethylic alcohol relative to the copper concentration, which has his maximum limit determined by the in force legislation providing traceability and reliability for the measurement results.

  9. Competitive evaluation of ORIMULSION as the fuel for thermoelectric generation; Estudo da competitividade do orimulsion como combustivel para geracao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Codeceira Neto, Alcides; Silva, Sergio Peres Ramos da [Companhia Hidroeletrica do Sao Francisco (CHESF), Recife, PE (Brazil)]|[Escola Politecnica de Pernambuco, Recife, PE (Brazil)

    1993-12-31

    Orimulsion is the denomination of a commercially new fuel, produced by Bitumenes Orinoco S.A. (BITOR) - Venezuela, constituted of natural bitumen emulsion in water in proportion of 7:3. It has a high hotness power (29260 kJ/kg or 7000 kCal/kg) and its price is about 48 US$/ton, to make it potentially attractive as a primary fuel for thermoelectric generation, due to the generation low cost of about 21,17 US$/MWh, when used in Rankine cycle, considering the thermic revenue of 30%. Its application in a combined cycle with integrated gas boiler reduces the fuel cost to 16,46 US$/MWh, considering the revenue of 45% 7 refs., 5 figs., 3 tabs.

  10. Bilayer electrolyte-anode for solid oxide fuel cell; Obtencao de bicamadas eletrolito-anodo para pilhas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Crochemore, G.B.; Marcomini, R.F.; Souza, D.P.F. de [Universidade Federal de Sao Carlos (GEMM/UFSCAR), Sao Carlos, SP (Brazil). Programa de Pos Graduacao em Ciencia e Engenharia de Materiais], Email: dulcina@ufscar.br; Rabelo, A.A. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Fac. de Engenharia de Materiais

    2010-07-01

    Solid oxide fuel cell is a high efficient device hence it plays a very important role in the hydrogen economy. However, the cell operation temperature must be lower than 800 deg C, what is attainable for thin Yttria stabilized zirconia (YSZ) electrolytes. The tape casting process is the most used technique because it allows a very fine tuning of the tape thickness. In this work it were investigated the processing conditions for obtaining electrolyte-anode (YSZ/ YSZ-NiO) bilayers with no lamination after the sintering process. (author)

  11. Polyethylene (PE) based proton exchange membrane for use in fuel cell; Obtencao de membranas trocadoras de protons a base de polietileno para uso em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Gilberto de Oliveira

    2008-07-01

    The irradiation - induced graft of styrene onto polyethylene (PE) in a Cobalt-60 source was carried out using direct (simultaneous) and indirect (preirradiation and peroxidation) methods at room temperature. The dose applied in both cases varied from 0,5 to 80 kGy; In the direct method, the films were immersed in a solution of styrene: methanol (30:70 v/v) and 30% of sulfuric acid(additive) in glass ampoules of 40 ml under inert atmosphere, and then irradiated. After irradiation process, the samples were kept in solution for 8 hours and taken off the ampoules, dried in oven at 60 deg C for another 8 hour period until constant weight. In pre-irradiation method, the samples were irradiated in dry and sealed ampoules, under inert atmosphere. The solution was then added to the samples, and after 8 hours, taken off, dried, sealed and weighted. In peroxidation method, the difference was not inert atmosphere but atmosphere of air (0{sub 2}).For each samples it was calculated the degree of grafting (DOG). The samples that showed some DOG were sulfonated, characterized (DSC, TGA and infrared) and the ion exchange capacity (IEC) was calculated. The samples processed by indirect method presented no DOG at all. The samples processed by direct method present grafting (best result was 80 kGy). These samples, after sulfonated, presented ion exchange properties. (author)

  12. Production logistic for an attack nuclear submarine squadron fuel; Logistica de producao de combustivel para um esquadrao de submarinos nucleares de ataque

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Leonam dos Santos [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), SP (Brazil)

    1999-08-01

    The future acquisition of nuclear attack submarines by Brazilian Navy along next century will imply new requirements on Naval Logistic Support System. These needs will impact all the six logistic functions. Among them, fuel supply could be considered as the one which requires the most important capacitating effort, including not only technological development of processes but also the development of a national industrial basis for effective production of nuclear fuel. This paper presents the technical aspects of the processes involved and an annual production dimensioning for an squadron composed by four units. (author)

  13. Estimate of fuel burnup spatial a multipurpose reactor in computer simulation; Estimativa da queima espacial do combustivel de um reator multiproposito por simulacao computacional

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Nadia Rodrigues dos, E-mail: nadia.santos@ifrj.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio de Janeiro (IFRJ), Paracambi, RJ (Brazil); Lima, Zelmo Rodrigues de; Moreira, Maria de Lourdes, E-mail: malu@ien.gov.br, E-mail: zrlima@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    In previous research, which aimed, through computer simulation, estimate the spatial fuel burnup for the research reactor benchmark, material test research - International Atomic Energy Agency (MTR/IAEA), it was found that the use of the code in FORTRAN language, based on the diffusion theory of neutrons and WIMSD-5B, which makes cell calculation, bespoke be valid to estimate the spatial burnup other nuclear research reactors. That said, this paper aims to present the results of computer simulation to estimate the space fuel burnup of a typical multipurpose reactor, plate type and dispersion. the results were considered satisfactory, being in line with those presented in the literature. for future work is suggested simulations with other core configurations. are also suggested comparisons of WIMSD-5B results with programs often employed in burnup calculations and also test different methods of interpolation values obtained by FORTRAN. Another proposal is to estimate the burning fuel, taking into account the thermohydraulics parameters and the appearance of xenon. (author)

  14. Fabrication and tests of anode supported solid oxide fuel cell; Fabricacao e testes de celula a combustivel de oxido solido suportada no anodo

    Energy Technology Data Exchange (ETDEWEB)

    Florio, D.Z. de [UNESP, Araraquara, SP (Brazil)], e-mail: dzflorio@ipen.br; Fonseca, F.C.; Franca, Y.V.; Muccillo, E.N.S.; Muccillo, R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Berton, M.A.C.; Garcia, C.M. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil)

    2006-07-01

    A laboratory setup was designed and put into operation for the development of solid oxide fuel cells (SOFCs). Ceramic single cells were fabricated by low-cost methods, and emphasis was given to the use of ready available raw materials. The whole project consisted of the preparation of the component materials - anode, cathode, and electrolyte - and the buildup of a hydrogen leaking-free sample chamber with platinum leads and current collectors for measuring the electrochemical properties of single SOFCs. Anode-supported single SOFCs of the type (ZrO{sub 2}:Y{sub 2}O{sub 3} + NiO) anode / (ZrO{sub 2}:Y{sub 2}O{sub 3}) electrolyte / (La{sub 0.65}Sr{sub 0.35}MnO{sub 3} + ZrO{sub 2}:Y{sub 2}O{sub 3}) cathode have been prepared and tested at 700 deg C and 800 deg C after in situ H{sub 2} anode reduction. The main results show that the slurry coating method resulted in single-cells with good reproducibility and reasonable performance, suggesting that this method can be considered for fabrication of SOFCs. (author)

  15. Methodology study for the catalyst obtention to low temperature fuel cells (DEFC); Estudo da metodologia de obtencao de catalisadores para celulas a combustivel de baixa temperatura (DEFC)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Emilia Lucena de; Korb, Matias De Angelis; Correa, Patricia dos Santos; Radtke, Claudio; Malfatti, Celia de Fraga [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil); Rieder, Ester [Universidade Luterana do Brasil (ULBRA), Canoas, RS (Brazil)

    2010-07-01

    Different methods to elaboration of catalysts in direct ethanol fuel cells (low temperature fuel cells) have been proposed in the literature. The present work aims to study a simplified methodology to obtain Pt-Sn-Ni alloys, used as catalysts in low temperature fuel cells. Impregnation/reduction method was employed to obtain Pt- Sn-Ni alloys supported on carbon, using ethylenoglycol as reductor agent and carbon Vulcan XC72R as support. Different amounts of Pt, Sn e Ni were studied, with the intent to obtain the maximum catalytic effect. The catalysts were obtained in an alkaline range, at 130 deg C, using the proportion ethylenoglycol:water 75/25 v/v. The analytical techniques used in this study was RBS (Rutherford Backscattering Spectroscopy), X Ray Diffraction and Cyclic Voltammetry. (author)

  16. Solar dehydration of the water hyacinth and his characterization as fuel; Desidratacao solar do jacinto d'agua e sua caracterizacao como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcio Amaral de [Universidade Salgado de Oliveira, Niteroi, RJ (Brazil). Dept. de Ciencias Exatas e Tecnologicas; Pinto, Carmen Lucia R. [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil). Div. de Meio Ambiente; Pereira, Roberto Guimaraes [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica

    1998-07-01

    Because of a new technology for waste water treatment utilizing water treatment utilizing water hyacinth as an instrument for water pollution control, studies were developed to profit the resultant biomass from this process proposing its utilization like an energy source after its dehydration. A direct exposition solar dryer with double glazing was utilized in the process. During the process were evaluated the following parameters: time of drying: physicochemistry characteristics of the plant; and inlet air, outlet air and inside air temperatures during the whole process of drying. (author)

  17. Adulteration determination of the anhydrous ethanol fuels samples with methanol; Determinacao de adulteracao por metanol em amostras de alcool etilico anidro combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Eduardo; Mota, Claudio J.A. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: eduardoc@dh.com.br; cmota@iq.ufrj.br

    2003-07-01

    A fast test made to evidence an adulteration of anhydrous ethanol with methanol consist in mixing the alcohol with gasoline. A pink coloration indicates the adulteration by methanol. Samples of gasoline A, ethanol and high purity methanol were mixed at different proportions, but no color change was observed. On the other hand, samples of gasoline A, ethanol and formaldehyde 40% showed the characteristic pink coloration, for methanol adulteration. This result indicates that the test is sensible to the presence of formaldehyde, probably presence as impurity or formed by oxidation of the methanol. A lower detection limit of 4.8% of formaldehyde in the alcohol was determined. (author)

  18. The elimination of corrosiveness of hydrated ethanol by using ion exchange resin; Eliminador da corrosividade do alcool etilico hidratado combustivel pelo tratamento com resinas de troca ionica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Aurelio N. de; Tanaka, Deniol K. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    1986-12-31

    Based on ion exchange principles and the chemical analysis of regularly produced hydrated alcohol and considering corrosion problems found when this alcohol is used as fuel, the use of ion exchange resins is proposed to purify hydrated alcohol and hence eliminate corrosiveness. This alternative takes advantage of high efficiency with significantly low cost compared to other alternatives or to surface treatments required as function of the aggressive characteristics of fuel. Available preliminary results shows a modification in the aggressive characteristics of alcohol fuel as well as the possibility to obtain adequate physico-chemical properties of final product and the ability to standardize products from different sources or regions. Additional research work and follow up from vehicles testings with treated alcohol were done and they confirm presented results. 12 figs., 6 tabs.

  19. Analysis of the fuel influence in obtaining HAp by combustion reaction; Analise da influencia do combustivel na obtencao de HAp via reacao de combustao

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.L.; Leite, A.M.D.; Viana, K.M.S., E-mail: kalineviana@ect.ufrn.br [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Escola de Ciencias e Tecnologia

    2016-07-01

    The search for new materials for biomedical applications has led to investigation of the calcium phosphate bioceramics, and in particular hydroxyapatite (HAp), being a material similar to bone tissue, with excellent biocompatibility and high osteoconduction, enabling bone regeneration which allows the use at implants and prostheses. The synthesis of the nanometric HAp by combustion reaction enables obtaining the nanometric HAp with a more similar structure biological apatite as possible. This work aims to synthesize HAp by combustion reaction using two different routes of synthesis, first, using urea as fuel and the second using glycine, after this, evaluate the influence of fuels used in the microstructure of the hydroxyapatite obtained. The HAp obtained was characterized by: XRD, FTIR and SEM. Through analysis of the results, there is the synthesis conditions used that glycine has performed more favorable to obtaining HAp. (author)

  20. The thermochemical of cerias in anodic conditions of fuel cell; A termoquimica de cerias nas condicoes anodicas de pilha a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Caffarena, Valeska da Rocha; Malta, Luiz Fernando Brum; Ogasawara, Tsuneharu [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais]. E-mail: valeska@metalmat.ufrj.br; Santos, Jorge Gomes dos [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)]. E-mail: jg@ien.gov.br

    2003-07-01

    Gibbs' free energies of cerias doped with rare earths estimated from experimental data on hydrothermal synthesis allowed to calculate and construct diagrams of log{sub 10} pH{sub 2}O/pH{sub 2} versus temperature and log{sub 10} pCO{sub 2}/pCO versus temperature, for x = 0.1 and x = 0.01 (where x = fraction of the original ceria converted to Ce{sub 2}O{sub 3}). These diagrams show that cerias doped with rare-earths are more stable than pure ceria, under contact with hydrogen gas or hydrogen-carbon monoxide gaseous mixture which is found in anode region of solid oxide fuel cells operated with pure hydrogen or in situ reformed hydrocarbons. Among doped cerias, the chemical stability increases in the order:: Ce{sub 1.7}Eu{sub .0.}3O{sub 3.85} , Ce{sub 7.47}Sm{sub 1.53}TbO{sub 18.735} , Ce{sub 0.8}La{sub 0.2}O{sub 1.9} e Ce{sub 0.8}Pr{sub 0.4}O{sub 1.8}. In the case of fuel cell operation with CO +H{sub 2} mixture, the Boudouard's equilibrium determines the operational conditions in log{sub 10} pCO{sub 2}/pCO versus temperature domain. (author)

  1. Study of PtNi/C catalyst for direct ethanol fuel cell; Estudo do catalisador PtNi/C para celula a combustivel de etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, L.P.R. de; Silva, E.L. da; Amico, S.C.; Malfatti, C.F., E-mail: eticiaprm@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2014-07-01

    In this work, PtNi binary catalyst and pure platin catalyst were synthesized by the impregnation-reduction method, using Vulcan XC72R as support, for direct ethanol fuel cells. The composition and structure of the catalysts were analyzed by X-ray diffraction, the electrochemical behavior was evaluated by cyclic voltammetry and morphology of the catalysts was studied by high-resolution transmission electron microscopy. The results showed that the addition of Ni to Pt led to the contraction of the crystal lattice, increased the catalytic activity compared to pure Pt and initiated the electrooxidation of ethanol at lower potential. (author)

  2. Multi-metallic anodes for solid oxide fuel cell applications; Anodos multi-metalicos para aplicacoes em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Restivo, T.A. Guisard; Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia dos Materiais; Leite, D. Will [Instituto de Pesquisas e Estudos Industriais (IPEI/FEI), Sao Bernardo do Campo, SP (Brazil). Fac. de Engenharia Industrial

    2009-07-01

    A new method for direct preparation of materials for solid oxide fuel cell anode - Ni- YSZ cermets - based on mechanical alloying (MA) of the original powders is developed, allowing to admix homogeneously any component. Additive metals are selected from thermodynamic criteria, leading to compacts consolidation through sintering by activated surface (SAS). The combined process MA-SSA can reduce the sintering temperature by 300 deg C, yielding porous anodes. Densification mechanisms are discussed from quasi-isothermal sintering kinetics results. Doping with Ag, W, Cu, Mo, Nb, Ta, in descending order, promotes the densification of pellets through liquid phase sintering and evaporation of metals and oxides, which allow reducing the sintering temperature. Powders and pellets characterization by electronic microscopy and X-ray diffraction completes the result analyses. (author)

  3. Bio desulfurization of a system containing synthetic fuel by rhodococcus erythropolis ATCC 4277; Remocao de compostos sulfurosos de sitema bifasico contendo combustivel sintetico por Rhodococcus erythropolis ATCC 4277

    Energy Technology Data Exchange (ETDEWEB)

    Maass, Danielle; Souza, Antonio Augusto Ulson de; Souza, Selene Maria de Arruda Guelli Ulson de [Universidade Federal de Santa Catarina (UFSC), SC (Brazil)

    2012-07-01

    For decades the burning of fossil fuels released a lot of pollutants in the atmosphere. Among the most harmful is sulfur dioxide (SO{sub 2}), which reacts with the moisture in the air and turns into sulfuric acid, being the main cause of acid rain. Acid rain is very harmful to animal and plant kingdoms; accelerates the corrosion's processes of buildings and monuments, and causes serious health problems for humans. As a result, many countries have reformed their legislation to require the sale of fuels with very low sulfur content. The existing processes of desulfurization are not capable of removing sulfur so low. Therefore, there has developed a new process called bio desulfurization. In this process, the degradation of sulfur occurs through the action of microorganisms that act as catalysts. The bacterium Rhodococcus erythropolis has emerged as one of the most promising for bio desulfurization because it removes the sulfur without breaking the benzene rings, thereby maintaining the potential energy of the same. Using dibenzothiophene as a model of sulfur compounds, the products of the bio desulfurization process are 2- hydroxybiphenyl and sulfate. In this study we sought to examine the desulfurizing capacity of national Rhodococcus erythropolis strain ATCC4277 in a batch reactor using concentrations of organic phase (n-dodecane) of 20 and 80% (v/v). Rhodococcus erythropolis ATCC4277 was capable of degrading DBT in 93.3 and 98.0% in the presence of 20 and 80% (v/v) of synthetic fuel, respectively. (author)

  4. Birds heater adaptation and performance using biogas as fuel; Avaliacao do desempenho de um aquecedor para aves adaptado para utilizar biogas como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-09-15

    It was carried out a trial to evaluate the adaptation (injector diameter) and performance (biogas consumption and heating efficiency) of a heating adapted to burn biogas. It was tried a common heater, burning liquefied petroleum gas (LPG), operating with low gas pressure (28 cm water column), with calorific capacity of 5024 kJ/h and recommended for 500 birds. The heater was evaluated with the original fuel (LPG) without any modification in the gas injector and after adapting to biogas burning. Five injectors were evaluated with drillings of 1,0053; 1,5080; 1,5708; 1,7672 and 1,980 mm{sup 2}. It also was varied the biogas pressures in the heater entrance of 10, 12, 15, 17 and 20 cm of water column. Results showed that expressions for theoretical calculation and proposed parameters in the literature can be used for aviaries heaters adaptation. The adaptation is simple, indicating the viability for utilization of existing heaters in farms and in the market. Air temperatures were similar to the obtained with the original fuel (LPG). (author)

  5. Polypropylene (PP) based proton exchange membrane for use in fuel cell; Obtencao de membrana trocadora de protons para uso em celula a combustivel, a base de polipropileno (PP)

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto

    2008-07-01

    The radiation-induced graft of styrene onto polypropylene (PP) films was carried out by simultaneous irradiation method in a cobalt-60 source. The PP films were immersed in a solution of styrene with toluene (1:1 and 4:1, v/v) under inert atmosphere and at room temperature and then submitted at 20, 40, 80 and 100 kGy. After graft reaction the films were kept at room temperature under inert atmosphere for periods of 7, 14, 21 and 28 days in order to evaluate the degree of grafting. At the end of each period the films were sulfonated to provide the hydrophilic property to PP. The degree of grafting (DOG) was gravimetric determined and the chemical changes in the grafted and sulfonated films were characterized by Infrared Spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry and the Ion Exchange Capacity (IEC) was calculated. The greatest DOG was obtained after 21 days of post-irradiation. By TGA the grafted films exhibited a decrease in the thermal stability, while the sulfonated exhibited an increase. By DSC was possible to verify that matrix polymeric did not suffer any drastic change in the melting temperature after grafting and sulfonation reactions. The IEC calculated shows that the new membrane developed has ionic conductivity property. (author)

  6. Biodegradation of radioactive organic liquid waste from spent fuel reprocessing; Biodegradacao de rejeitos radioativos liquidos organicos provenientes do reprocessamento do combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Rafael Vicente de Padua

    2008-07-01

    The research and development program in reprocessing of low burn-up spent fuel elements began in Brazil in 70's, originating the lab-scale hot cell, known as Celeste located at Nuclear and Energy Research Institute, IPEN - CNEN/SP. The program was ended at the beginning of 90's, and the laboratory was closed down. Part of the radioactive waste generated mainly from the analytical laboratories is stored waiting for treatment at the Waste Management Laboratory, and it is constituted by mixture of aqueous and organic phases. The most widely used technique for the treatment of radioactive liquid wastes is the solidification in cement matrix, due to the low processing costs and compatibility with a wide variety of wastes. However, organics are generally incompatible with cement, interfering with the hydration and setting processes, and requiring pre -treatment with special additives to stabilize or destroy them. The objective of this work can be divided in three parts: organic compounds characterization in the radioactive liquid waste; the occurrence of bacterial consortia from Pocos de Caldas uranium mine soil and Sao Sebastiao estuary sediments that are able to degrade organic compounds; and the development of a methodology to biodegrade organic compounds from the radioactive liquid waste aiming the cementation. From the characterization analysis, TBP and ethyl acetate were chosen to be degraded. The results showed that selected bacterial consortia were efficient for the organic liquid wastes degradation. At the end of the experiments the biodegradation level were 66% for ethyl acetate and 70% for the TBP. (author)

  7. Influence of heavy crude oil refining about the mains characteristics of jet fuel; Influencia do refino de petroleos pesados sobre as principais caracteristicas do combustivel de aviacao

    Energy Technology Data Exchange (ETDEWEB)

    Om, Neyda [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Cavado, Alberto; Reyes, Yordanka [Centro de Pesquisas do Petroleo, Cidade de Havana (Cuba); Salazar, Rodolfo [Centro de Eletromagnetismo Aplicado, Cidade de Havana (Cuba); Dominguez, Zulema [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

    2004-07-01

    The aviation technology in the world, is to use gas turbines engines feted for fuel type Jet A1. The main exigency of quality for this products is concentrated in extreme security and secure answer during the functioning. The conductivity and thermal stability to oxidation are the principals characteristics to assure these quality exigencies. The use of additives is the methods most used for establish the quality for international specification. The incorporation of heavy crude oils in mixtures to produce fuels has caused a diminution of the quality of the derivatives produced. High viscosity, density and high sulfur content in the heavy crude oils affect some of properties of the jet fuel, influencing in its composition, increasing the mercaptanes and total sulfur content, getting a jet fuel unstable, with low conductivity and highly corrosive. So, for obtain the quality required internationally is necessary use additives. This paper study how the heavy crude oils affect the conductivity and the thermal stability of the jets fuels type Jet A1. Also analyze of the use of dissipater electrostatic and antioxidants additives, to improve these properties in the jet fuel. (author)

  8. Balance of greenhouse gases emission in the life cycle of ethanol fuel; Balanco de emissao de gases de efeito estufa no ciclo de vida do etanol combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cinthia Rubio Urbano da [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Programa de Pos-Graduacao em Planejamento de Sistemas Energeticos; Walter, Arnaldo Cesar da Silva [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica

    2008-07-01

    The environmental focus of the use of biofuels is the reduction of green houses gases emissions through automobile exhaust; furthermore, the European Union has discussed the necessity of the requirement these reduction between 30 to 50% compared with the gasoline cycle. Inside this context, this paper joins and compares recent studies about green house gases emission balance of environmental life cycle of ethanol fuel derived form corn, wheat and sugar cane with the goal of recognize the reduction these emissions from the use of ethanol in function of the different alternatives of production. Results show that production of ethanol from sugar cane results higher reduction of green house gases emission compared with the gasoline. Ethanol from corn and ethanol from wheat meet, in the current conditions of Canadian production and use, the least requirement of 30% of saved emission. (author)

  9. Evaluation of ethanol aged PVDF: diffusion, crystallinity and dynamic mechanical thermal properties; Avaliacao do PVDF envelhecido em etanol combustivel: difusao, cristalinidade e propriedades termicas dinamico-mecanicas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Agmar J.J.; Costa, Marysilvia F., E-mail: agmar@metalmat.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This work discuss firstly the effect of the ethanol fuel absorption by PVDF at 60°C through mass variation tests. A Fickian character was observed for the ethanol absorption kinetics of the aged PVDF at 60°C. In the second step, the dynamic mechanical thermal properties (E’, E’, E” and tan δ) of the PVDF were evaluated through dynamic mechanical thermal analysis (DMTA). The chemical structure of the materials was analyzed by X-ray diffraction analysis (XRD), and significant changes in the degree of crystallinity were verified after the aging. However, DMTA results showed a reduction in the storage modulus (E') of the aged PVDF, which was associated to diffusion of ethanol and swelling of the PVDF, which generated a prevailing plasticizing effect and led to reduction of its structural stiffness. (author)

  10. Hybrid membranes PVA/silicon for use in fuel cells; Membranas hibridas de PVA/silica para aplicacao em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Liz C.V. de; Almeida, Raquel D. de; Gomes, Ailton de S. [Universidade Federal do Rio de Janeiro - UFRJ, Instituto de Macromoleculas Professora Eloisa Mano - IMA, RJ (Brazil)], e-mail: lizcontino@ima.ufrj.br; Ramos Filho, Florencio G. de [Centro Universitario Estadual da Zona Oeste - UEZO, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Hybrids organic-inorganic membranes PVA-silica have been prepared using sol-gel process in situ with the objective of study the influence of inorganic particles incorporation on the water uptake, pervaporation and proton conductivity of PVA membranes. The silica was constituted of mercaptopropyltrimethoxysilane (MPTMS) with or without the mixture with the tetra ethoxysilane (TEOS). The hybrids membranes were oxidated to convert the -SH groups in -SO{sub 3}H groups, becoming them proton conducting. The hybrids membranes not oxidated showed lesser water uptake and pervaporated material, probably, due to the formation of crosslink that restricted the swell of the PVA membrane. The protonic conductivity of the hybrid membranes after the oxidation was up to 26 times bigger than of the membrane not oxidated. (author)

  11. Obtaining fuel oils from the low temperature conversion of biomass waste; Obtencao de oleo combustivel a partir da conversao a baixa temperatura de biomassa residual

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberto Guimaraes; Cinelli, Leonardo Rodrigues [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica. Programa de Pos-Graduacao em Engenharia Mecanica]. E-mail: temrobe@vm.uff.br; Romeiro, Gilberto Alves; Damasceno, Raimundo Nonato [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Quimica Organica. Programa de Pos-Graduacao em Quimica Organica]. E-mail: gilbertoromeiro@ig.com.br; Senra, Paulo Mauricio de Albuquerque [Light Servicos de Eletricidade S.A., Rio de Janeiro, RJ (Brazil). Gerencia de Estudos e Gestao de Geracao]. E-mail: paulo.senra@light.com.br

    2004-07-01

    This paper refers to the characterization and application of oil obtained through the 'Low Temperature Conversion Process' applied to industrial waste generated in the treatment of effluent from the petrochemical industry. Physical and chemical parameters, such as viscosity, density, sulfur content, flash point, point of fluidity were obtained. The characterization of the oil obtained indicates the possibility of classifying it as oil fuel. Also, studying the application of the oil in engines. Developed from studies on the feasibility of producing biodiesel from sludge of sewage treatment plants in Germany of the 1980s, the 'Low Temperature Conversion-LTC' technique, is a thermo chemical process, whose main goal is to extend the life of liabilities environment. The LTC is being applied in various biomass of urban, industrial and agricultural origin, looking up through the thermal conversion transform them into products of potential commercial value. Depending on the type of biomass used in the process, are obtained a fraction lipophilic and a carbonaceous solid waste in a varying of proportions, plus a fraction hydrophilic and conversion gas. The lipophilic fraction is targeted to studies about the feasibility of its application as fuel or other compounds with possible commercial application (such as greases, oils, resins, etc.), while the carbonaceous residue is directed to studies about its activation for the used as activated charcoal, in addition to the possible direct use as energy.

  12. Síntese e atividade biológica do derivado 6-formil-oxamniquina Synthesis and biological activity of 6-formyl-oxamniquine derivative

    Directory of Open Access Journals (Sweden)

    Adélia Emília de Almeida

    2008-12-01

    Full Text Available A esquistossomose, uma importante doença no Brasil, é causada por trematódeo pertencente ao gênero Schistosoma, atingindo milhões de pessoas, numa das maiores regiões endêmicas dessa doença em todo globo. O principal objetivo desse trabalho foi sintetizar o derivado 6-formil-oxamniquina e avaliar sua atividade biológica. O derivado 6-formil- oxamniquina foi obtido por oxidação da oxamniquina com dióxido de manganês empregando diclorometano como solvente, à temperatura ambiente, por 24 horas. Sua obtenção foi confirmada por espectrometria na região de infravermelho e espectroscopia de RMN 13C e ¹H, apresentando atividade similar quando comparada à oxamniquina comercial (Mansil®.Schistosomiasis, an important disease in Brazil, is caused by a trematode of the genus Schistosoma, reaching millions of person in one of the most endemic region of this disease in the whole globe. The main goal of this work was to syntetize the 6-formyl-oxamniquine derivative and evaluate its biological activity. The 6-formyl-oxamniquine derivative was obtained by the oxidation of oxamniquine with MnO2, applying CH2Cl2 as solvent at room temperature for 24 hours. The obtaintion of 6-formyl-oxamniquine derivative compound was confirmed by IR spectroscopy and 13C NMR and ¹H NMR, presenting similar activity when compared to the commercial oxamniquine (Mansil®.

  13. Espectrofotometria de zinco em fertilizantes em fluxo Flow injection spectrophotometry of zinc in mineral fertilizers

    Directory of Open Access Journals (Sweden)

    Arnaldo Antonio Rodella

    1999-07-01

    Full Text Available Um sistema de análise química por injeção em fluxo é proposto para a determinação espectrofotométrica de zinco em amostras de misturas de fertilizantes minerais, empregando-se zincon como reagente cromogênico. O procedimento analítico envolve redução de íons metálicos por ácido ascórbico, complexação com íon cianeto, seguindo-se a descomplexação seletiva do zinco com formaldeído, liberando-o para que reaja com o zincon formando um complexo azul. A aplicação do método proposto à extratos de mistura de fertilizantes indicou que a ação de interferentes pode ser contornada e que resultados comparáveis aos da espectrometria de absorção atômica são obtidos.A flow injection system for zinc analysis in mineral fertilizer mixtures is proposed using zincon as chromogenic reagent. The effect of interfering ions such as Cu2+, Fe3+, Mn2+ was eliminated by reduction (using ascorbic acid and complexation of these metal íons with cyanide, with zinc included. Zinc is allowed to react with zincon only after the destruction of the zinc cyano complex with formaldehyde. Flow injection analysis permitted efficient control of the reaction time so that only the zinc ion is set free to produce a blue complex with zincon. Zinc was determined in 16 fertilizer mixtures (3 replicates with precision and accuracy comparable to atomic absorption spectrometry.

  14. Spectrometry and dosimetry of isotopic sources of neutrons by means of artificial neural networks; Espectrometria y dosimetria de fuentes isotopicas de neutrones mediante redes neuronales artificiales

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R.; Ortiz R, J. M.; Hernandez D, V. M; Martinez B, M. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C/Jose Gutierrez Abascal No. 2, 28006 Madrid (Spain); Barquero, R., E-mail: fermineutron@yahoo.co [Hospital del Rio Hortega, C/Dulzaina No. 2, 47012 Valladolid (Spain)

    2010-09-15

    The artificial neural networks technology has been applied to reconstruct the neutrons spectra of two isotopic sources: {sup 252}Cf, and {sup 241}Am-Be. Also, this technology has been applied to obtain the effective dose, E, and the personal dose equivalents, Hp(10) and environmental, H *(10). To obtain the spectra and the doses only were used the count rates produced in a Bonner Spheres spectrometer with a scintillator of {sup 6}LiI(Eu) of 0.4 {phi} x 0.4 cm{sup 2}. The equivalent environmental dose and the spectra of the sources were also obtained by means of the reconstruction code BUNKIUT. When comparing the results obtained by means of both procedures it was found that they are consistent. (Author)

  15. Gamma spectrometry used for analysis of {sup 228}Ra in water; Utilizacao de espectrometria gama para analise de {sup 228} Ra nas aguas

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Luis Henrique [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas; Bonotto, Daniel Marcos [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas. Dept. de Petrologia e Metalogenia

    1998-07-01

    A methodology for determination of the natural isotope {sup 228}Ra in water by using the characterization of the underground and superficial waters from thorium an rare earths mineralization at Morro do Ferro, Pocos de Caldas, state of Minas Gerais, Brazil. The values determined for the {sup 228}Ra in water from 5 logging holes ranged from 0.5 to 391.2 pCi/l and the superficial waters presented a variation of 1.0 to 13.9 pCi/l.

  16. Análise de innterferon humano recombinante presente em formulações farmacêuticas por espectrometria de massa

    OpenAIRE

    Andrade, Sinéa Mendes de

    2010-01-01

    Os interferons (INFs) são proteínas produzidas por células animais em resposta a infecções virais. Essas substâncias possuem vários efeitos farmacológicos, incluindo antiviral, antitumoral e imunomodulatório. Com o advento da tecnologia do DNA recombinante, vários interferons passaram a ser produzidos e comercializados como Biofármacos. O mais importante é o α2b, que é uma das bases do tratamento das hepatites virais. A única norma oficial que regulamenta a produção de INF-α2b é a Farmacopéia...

  17. Padronização interna em espectrometria de absorção atômica Internal standardization in atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Kelly G. Fernandes

    2003-03-01

    Full Text Available This paper describes a review on internal standardization in atomic absorption spectrometry with emphasis to the systematic and random errors in atomic absorption spectrometry and applications of internal standardization in flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry. The rules for selecting an element as internal standard, limitations of the method, and some comments about the application of internal standardization in atomic absorption spectrometry and the future of this compensation strategy are critically discussed.

  18. Development of a system for passive spectrometry characterization neutron of a cyclotron; Desarrollo de un sistema de espectrometria pasivo para la caracterizacion neutronica de un ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, R.; Guerrero, J. E.; Lagares, J. I.; Sansaloni, F.; Perez, J. M.; Llop, J.; Kralik, M.

    2013-07-01

    The most widely used for Neutron spectrometry system is formed by the Bonner spheres with an active sensor sensitive to thermal neutrons in its Center. But, the presence of strong electromagnetic fields and the hold character around a cyclotron radiation detectors active employment make unviable so it is necessary to replace it with other liabilities. In this case it has resorted to the use of Au foils such as thermal neutron detectors, found the matrix the new spectrometer response and has been validated with a source of {sup 2}52Cf for later measurements in the interior of the bunker of a cyclotron production of radioisotopes for PET. (Author)

  19. Gamma spectrometric validation of measurements test of radionuclides in food matrices; Validacao do ensaio de medidas por espectrometria gama de radionuclideos em matrizes de alimentos

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Custodio, Luis G.; Bonifacio, Rodrigo L.; Taddei, Maria Helena T., E-mail: mychelle@cnen.gov.br, E-mail: Igcustodio@hotmail.com, E-mail: rodrigo@cnen.gov.br, E-mail: mhtaddei@cnen.gov [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), de Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2013-10-01

    In a testing laboratory the quality system encompasses a set of activities planned and systematic, which ensure the traceability process of an analysis, which is based on the standards NBR ISO/TEC 17025. With the need for analysis of radionuclides in food products to meet the requirements of import and export, accreditation of testing on this standard becomes increasingly necessary. The Gamma Spectrometry is a technique used for direct determination of radionuclides in different matrices, among them the food, being possible the simultaneous determination of different radionuclides in the same sample without the need for a chemical separation. In the process of Accreditation the methodology validation is an important step that includes testing accuracy, traceability, linearity and recovery. This paper describes the procedures used to validate the assay for determining radionuclides using gamma spectrometry in food. These procedures were performed through analysis of a certificated reference material by the International Atomic Energy Agency (IAEA Soil 327), analysis of samples of milk powder prepared from the doping with certified liquid standards also by the results obtained in the participation of tests of proficiency in analysis of environmental samples. (author)

  20. Methodology of the carbonates dating by the uranium series unbalance by mass spectrometry; Metodologia de datacao em carbonatos pela serie de desiquilibrio do uranio por espectrometria de massa

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Barbara Alcantara Ferreira

    2006-07-01

    There are many dating methods largely used according to the kind of material to be dated. Methods that rely on the time-dependency of geochemical disequilibrium between daughter and parent isotope, from the '2{sup 38}U, {sup 235}U and {sup 232}Th natural decay system, whose final members are stable Pb isotopes, are the most useful in a broader variety of geological, hydrological and archaeological problems. The use of this method in cave deposits like speleothems and clastic sediments proved to be a powerful tool to study past climatic and environmental changes. Speleothems like stalagmites are frequently used in paleoenvironmental interpretations. This method may be applied to rocks and underground water dating, erosion studies, transport and sedimentation processes, interactions between rock-groundwater, among others. The present work focuses on the chemical preparation of the U-Th method including the chemical procedures to avoid laboratory contamination and the mass spectrometer precise calibration in order to get high reproducibility. The process has many steps: samples preparation; digestion and chromatographic separation using standards and samples already dated in other laboratories; determination of the isotopic ratios by mass spectrometers, and a case study based on a stalagmite from Joao Arruda cave, Bonito, Mato Grosso State, Brazil. The obtained data shows the reliability of the method works, mostly in relation to co precipitation of U and Th and to the chromatographic separation of these metals. It is also observed that the obtained dates are within the errors for each sample and are very similar to the dates obtained in other laboratories (validated to this methodology). Further improvements are necessary to achieve better results, mostly related to the reading method in the MC-ICP-MS. The case study in the JA-5 stalagmite shows that it stopped growing around 2,0 ky. This is a different result from that obtained on JA-3 stalagmite, from the same cave, but placed in a spot with different hydrodynamics. (author)

  1. Espectrometria de massas com ionização por "electrospray" aplicada ao estudo de espécies inorgânicas e organometálicas

    Directory of Open Access Journals (Sweden)

    Moraes Maria Carolina B.

    2003-01-01

    Full Text Available Although electrospray ionization mass spectrometry (ES-MS has been extensively applied to study organic and biochemical species, it is also specially suitable to study inorganic and organo-metallic species. Such species, even those that are low-volatile or thermo-unstable, can be easily ionized or simply transferred from liquid to gas phase by electrospray. However, chemical transformations frequently occur during the process. This paper discusses the fundamental aspects of electrospray ionization as well as its analytical applicability to inorganic and organo-metallic species in order to spread the technique and make its characteristics more familiar to potential users.

  2. Atribuição absoluta e geral de isômeros constitucionais por espectrometria de massas: o caso das metilpiperidinas

    Directory of Open Access Journals (Sweden)

    Marcos N. Eberlin

    2012-01-01

    Full Text Available An absolute method is described via mass spectrometry (MS for the structural assignment of isomers within the class of methylpiperidines. The method explores both the unimolecular and bimolecular gas phase behavior of structurally diagnostic fragment ions (SDFI. For the methylpiperidnes, the isomeric 2-methyl, 3-methyl and 4-methyl 2-azabutadienyl cations are found to function as SDFI. These fragment ions are expected to be formed from all members within the class, to be stable and to retain the structural information of the precursor molecule, and to not interconvert into one another. To characterize these SDFI, both the collision induced dissociation (CID in argon and bimolecular ion/molecule chemistry with ethyl vinyl ether were compared.

  3. A geração química de vapor em espectrometria atômica Chemical vapor generation in atomic spectrometry

    Directory of Open Access Journals (Sweden)

    Iracema Takase

    2002-12-01

    Full Text Available The historical development of atomic spectrometry techniques based on chemical vapor generation by both batch and flow injection sampling formats is presented. Detection via atomic absorption spectrometry (AAS, microwave induced plasma optical emission spectrometry (MIP-OES, inductively coupled plasma optical emission spectrometry (ICP-OES , inductively coupled plasma mass spectrometry (ICP-MS and furnace atomic nonthermal excitation spectrometry (FANES are considered. Hydride generation is separately considered in contrast to other methods of generation of volatile derivatives. Hg ¾ CVAAS (cold vapor atomic absorption spectrometry is not considered here. The current state-of-the-art, including extension, advantages and limitations of this approach is discussed.

  4. Neutron spectrometry in the temporary storage of waste of the Jose Cabrera (Zorita); Espectrometria de neutrones en el almacen temporal de residuos de la central Jose Cabrera (Zorita)

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, C.; Amgarou, K.

    2011-07-01

    Radiation controls the temporary storage of waste must ensure that the exterior of the same area is classified as open access. Gamma radiation monitors commonly used ensure that this is the case for this type of radiation. The presence of the neutron field associated with the fission of the fuel and the inherent complexity of the neutron dosimetry, in which information is required to assess spectrometric corresponding dosimetric quantities, has led to this season, first in Spain, measures in containers of waste and spent nuclear fuel in the ATI of the Jose Cabrera.

  5. Methodology for unconditional declassification of waste materials by gamma spectrometry; Metodologia para la desclasificacion incondicional de materiales residuales mediante espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Gomez, M. A.; Gonzalez Gandal, R.; Socorro Garcia, G.; Garcia Acosta, F.

    2013-07-01

    This paper aims to present the methodology for conventional materials management through its declassification and can be used by all Spanish nuclear power plants. The methodology is based on management through declassification unconditional, ie, there are no restrictions on the origin, type of material and the final destination. (Author)

  6. Eletroforese capilar acoplada à espectrometria de massas (CE-MS: vinte anos de desenvolvimento Capillary electrophoresis coupled to mass spectrometry (CE-MS: twenty years of development

    Directory of Open Access Journals (Sweden)

    Nilson Antonio Assunção

    2008-01-01

    Full Text Available CE-MS has been increasingly used for analysis of a vast array of compounds. This article reviews the different electrophoretic modes, interfaces and mass analyzers that are commonly used in the CE-MS coupling, as well as the technique advantages and performance characteristics. A large compilation of CE-MS applications is also presented. Therefore, this review is both a guide for beginners and a collection of key references for people who are familiar to the technique. Furthermore, this is the first CE-MS review published in a Brazilian journal and marks the installation of the first two commercial CE-MS units in Sao Paulo State.

  7. A new computation tool for neutron spectrometry and dosimetry; Una nueva herramiento de computo para la espectrometria y dosimetria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Martinez B, M. R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico)], e-mail: mrosariomb@yahoo.com.mx

    2009-10-15

    By using the integrated accounts of spectrometric system of Bonner spheres is possible to reconstruct the neutron spectrum using various methods such as: Monte Carlo, the parameterization and iterative methods. The response matrix, counting rates and neutron spectrum are intimately related through the integral-differential of Fredholm of first type. however, the weight of Bonner spheres system, the procedure of spectra reconstruction, the need of a expert user, the high time consumption, the need to use a reconstruction code (BUNKI, SAND, among others) and the spectrum resolution, are some of problems that this system presents. The above difficulties have motivated the development of complementary procedures such as maximum entropy, genetic algorithms and artificial neural networks. In recent years, using neural network technology has become an alternative procedure in the nuclear science research area, considering a replacement for classical techniques used for years. In previous works, was used a new method called robust design methodology of artificial neural networks, to construct various network topologies capable of solving the problems of neutron spectrometry and dosimetry, however noted that not exist tools for end-user that allow test and validate the designed networks. This paper presents the development of a software for neutronic spectrometry and dosimetry, based on information extracted from an artificial neural network designed in previous work, through the robust design methodology of artificial neural networks with the following characteristics: was designed in a user graphical interface easy to use, speed on the application execution, unlike other deconvolution codes, not is necessary to select and initial spectrum for spectrum reconstruction, as an additional element to this tool, besides spectrum, the calculation is performed simultaneous of 13 equivalent dose from just counting rates from a spectrometric system of Bonner spheres. (Author)

  8. Experimental study of the burned of nuclear fuel by the gamma spectroscopy method; Estudio experimental del quemado de combustible nuclear por el metodo de espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Amador V, P.

    2009-07-01

    Accurate information on nuclear fuel burnup is of vital importance in reactor operation, fuel management and fuel-characteristics studies. Conventionally fuel management of the TRIGA III Reactor from the National Institute of Nuclear Research (ININ) is done through the thermal balance method (management) of the power generated during reactor operation, since it is known that with 1.24 grams of {sup 235}U is possible to generate a power or 1 MW per day during the reactor operation. On the other hand, it is possible to calculate the operation time in days during a power of 1 MW with the help of the data registered in logs. With the information just mentioned one can calculate the quantity of {sup 235}U consumed in the fuel during a complete period of irradiation. In order to compare and prove that the burnup values, calculated through the thermal balance method, are correct, the ININ implemented, for the first time, the gamma-ray spectroscopy method as an experimental technique to calculate the burnup of several fuel elements. Gamma-ray spectroscopy is a nondestructive method, so that the integrity of the fuel element is not affected which is of great importance. Since there is a direct relation between the activity of {sup 137}Cs contained in the fuel elements and a series of constants which are unique for the radioisotope and for the high resolution system, the problem just simplifies in measuring the {sup 137}Cs activities. Furthermore the {sup 137}Cs concentration equation was developed theoretically and I wrote a computer program (AMAVAL) in Fortran. The task of this program is to calculate the concentrations and the activity through the use of the equation just mentioned and the history of each fuel element. The purpose of this is to compare and validate the experimental activities with the theoretical ones for each fuel element. (Author)

  9. Development of a portable system of X-ray fluorescence spectrometry; Desenvolvimento de um sistema portatil de espectrometria por fluorescencia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Andrea; Crisostomo, Jose V.V.; Barros, Mariana J.; Oliveira, Luis F.; Barroso, Regina C., E-mail: andreafisica@yahoo.com.b, E-mail: jose_vicente_crisostomo@yahoo.com.b, E-mail: mariana_jbarros@yahoo.co, E-mail: lfolive@oi.com.b, E-mail: cely_barroso@hotmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2009-07-01

    This paper develops a compact and portable spectrometry system that will be used at the Laboratory of Applied Physics to the Biomedical and Environmental Sciences of the Institute of Physics/UERJ, Rio de Janeiro, Brazil. The laboratory both prepares the samples and develops the X-ray spectrometry techniques. The techniques of X-ray diffraction and fluorescence on various samples (biological, industrial and environmental) are used, attending to pos-graduation and graduation students, with multidisciplinary characteristics. The Mini-X system consists of X-ray mini tube MINI-X from Amptek with tungsten (W) target, and a compact spectrometer X123, also from Amptek that includes a detector, pre-amplifier, digital pulse processor, and multichannel. All the system is controlled by dedicated microprocessor. This work will present both a methodology for alignment and calibration of the system as far the first measurements performed using the X-ray fluorescence technique on standard samples. The multi elementary analysis by X-ray fluorescence (XRF) is based on the measurements of the characteristic X-ray intensity emitted by the chemical elements components of the samples when excited. Therefore, from the development of this compact and versatile system it will be possible to obtain the fluorescent intensities of the analysed samples at the Laboratory, not only at the research area but at the teaching area. Besides, new laboratory practices are being developed for the discipline of medical physics

  10. Eletroforese capilar acoplada à espectrometria com plasma: uma ferramenta eficiente para a especiação Capillary electrophoresis coupled to plasma spectrometry: an efficient tool for speciation

    Directory of Open Access Journals (Sweden)

    Ana Paula G. Gervasio

    2003-01-01

    Full Text Available The most important features of the CE-ICP hyphenation, as well as its advantages and drawbacks as a tool for speciation are discussed. The fundamental principles of capillary electrophoresis and inductively coupled plasma mass spectrometry are also presented. Some applications involving different designs proposed in the literature to couple CE and ICP system for elemental speciation are reviewed.

  11. Seqüenciamento de peptídeos usando espectrometria de massas: um guia prático Peptide sequencing using mass spectrometry: a practical guide

    Directory of Open Access Journals (Sweden)

    Marcelo Delmar Cantú

    2008-01-01

    Full Text Available This paper introduces the basics of peptide mass spectra interpretation applied to proteomics and is directed to chemists, biochemists and biologists. The manuscript presents a well detailed protocol aiming to serve as a first choice guide for understanding peptide sequencing. The tutorial was elaborated based on both a thorough bibliographic revision and the author's experience. In order to prove the applicability of the proposed guide, spectra obtained on different instruments have been successfully interpreted by applying the presented rational.

  12. Experimental determination of B R-12 attenuation coefficients utilizing photon spectrometry;Deteminacao experimental de coeficientes de atenuacao de BR-12 atraves de espectrometria de fotons

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose N.; Terini, Ricardo A. [Pontificia Universidade Catolica de Sao Paulo (PUC-SP), Sao Paulo, SP (Brazil). Dept. de Fisica; Herdade, Silvio B. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia (IEE). Secao Tecnica de Desenvolvimento Tecnologico em Saude

    2009-07-01

    In tests for quality assurance in mammography, it is common to use breast phantoms, with different compositions. One of the most used is the BR-12 phantom. There are few published experimental data on the attenuation of BR-12. Generally, the available attenuation coefficients are calculated from the composition of the coefficients determined for its components. In this work, the spectrometric method was used, with a CdTe detector, for X- and {gamma}-rays from radioactive sources of {sup 133}Ba and {sup 241}Am. The spectra of direct and attenuated by 0.5 cm of BR-12 beams were measured. From the ratio of intensities obtained for these radiations, it was possible to determine values of the attenuation coefficients from Beer's law. Results show coherence with previous data. The values of such coefficients are useful, for example, for calculations of absorbed dose (in BR-12), which have been made on other research activities of this group. (author)

  13. Estudo da influência dos particulados no fenômeno de agregação dos asfaltenos por espectrometria de varredura óptica

    Directory of Open Access Journals (Sweden)

    Claudete Bernardo Henriques

    2011-01-01

    Full Text Available The processing of national petroleums causes many operational problems due to the asphaltene aggregation phenomena. To evaluate the behavior of these phenomena, a study based on optical scan technique was carried out to understand the behavior of pure oils and their mixtures. The evaluation according to criteria established by ASTM D7061-06¹ gives a result of asphaltene flocculation of according to the separability number. In this study, the aspects related to the existence of colloidal forms of peptized asphaltenes in distinct solvents present in petroleums can cause changes in the kinetics of asphaltene flocculation.

  14. IDENTIFICAÇÃO DE COMPOSTOS ORGÂNICOS EM LIXIVIADO DE ATERRO SANITÁRIO MUNICIPAL POR CROMATOGRAFIA GASOSA ACOPLADA A ESPECTROMETRIA DE MASSAS

    Directory of Open Access Journals (Sweden)

    Eliane Sloboda Rigobello

    2015-07-01

    Full Text Available The organic compounds present in leachate can contaminate soil, superficial and underground water, and the majority is considered harmful to the environment and human health. The objective of this study was to identify organic compounds present in landfill leachate located in Maringá-PR by gas chromatography coupled to mass spectrometry (GC-MS. The raw leachate was characterized by measurements of pH, Chemical Oxygen Demand (COD, Biochemical Oxygen Demand (BOQ, Dissolved Organic Carbon (DOC, apparent and true colors, turbidity and absorbance at 254 nm. The extraction of organic compounds in leachate was carried out by liquid-liquid extraction (LLE with ethyl acetate and dichloromethane solvents, while varying the pH and ionic strength. The analysis of the leachate by GC-MS showed the presence of compounds considered to have toxic effects on the environment and human health, such as pesticides and phenolic compounds. Several compounds containing oxygenated groups such as carboxylic acids and alcohols were also identified, indicating that it was highly probable that the decomposition of waste in the landfill was in the acidogenic phase.

  15. Análise quiral por espectrometria de massas através da utilização do método cinético

    Directory of Open Access Journals (Sweden)

    Augusti Daniella Vasconcellos

    2006-01-01

    Full Text Available Novel and quantitative mass spectrometry methods for rapid and accurate enantiomeric excess determination are presented. These methodologies use electrospray ionization (ESI and mass spectrometry (MS to detect and analyze, via collision-induced dissociation (CID, mass-selected transition metal complexes that promote enantio especific interactions. The data from CID are conveniently treated by the kinetic method, a sensitive linear free energy method of treating mass spectrometric results. Four different variations of this methodology are described: single ratio method (S R, quotient ratio method (Q R, fixed ligand method (S Rfixed, and quotient ratio method with fixed ligand (Q Rfixed. These individual methods are compared and their main features discussed in detail.

  16. Methodology for determination of activity of radionuclides by gamma spectrometry; Metodologia para determinacao da atividade de radionuclideos por sistema de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

    2014-07-01

    Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

  17. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement; Medida de los descendientes del radon en aire por Espectrometria Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Acena, M. L.; Crespo, M. T.

    1989-07-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs.

  18. {sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

    1999-03-01

    The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  19. X-Ray Fluorescence Spectrometry. II Determination of Uranium in ores; Espectrometria de fluorescencia de Rayos X. II-Aplicacion a la determinacion de uranio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

    1961-07-01

    A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L {alpha}{sub 1} spectral line is calculated and related to corresponding strontium-K{sub {alpha}} spectral line, both detected with a Scintillation Counter. (Author) 31 refs.

  20. X-Ray Fluorescence Spectrometry. I.- Determination of thorium in ores; Espectrometria de fluorescencia de rayos X. A.- Aplicacion a la determinacion de torio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

    1961-07-01

    A X-ray spectrometric method has been developed for analysis of thorium in ores in the range of concentration from 0.01 to 0.5 percent ThO{sub 2}, using selenium as a internal standard. The concentration of thorium is determined in a working curve prepared by plotting the percentage of ThO{sub 2} against the ratio intensity of the Th L{alpha}{sub 1} line to Sek{sub {beta}}1 line. (Author) 17 refs.

  1. Estudo por espectrometria de massas de soluções de hidróxi(tosilóxiiodobenzeno: propostas para mecanismos de desproporção

    Directory of Open Access Journals (Sweden)

    Ramon S. Vasconcelos

    2012-01-01

    Full Text Available Solutions of [hydroxy(tosyloxyiodo]benzene (HTIB or Koser's reagent in acetonitrile were analyzed using high resolution electrospray ionization mass spectrometry (ESI-MS and electrospray ionization tandem mass spectrometry (ESI-MS/MS under different conditions. Several species were characterized in these analyses. Based on these data, mechanisms were proposed for the disproportionation of the iodine(III compounds in iodine(V and iodine(I species.

  2. Microanálise de cálculos urinários por espectrometria de massa de iões secundários

    OpenAIRE

    Cangueiro, Liliana Teresinho

    2010-01-01

    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Biomédica Os cálculos urinários são uma patologia que afecta cerca de 10% da população mundial. Foram estudados neste trabalho dois dos compostos que ocorrem com mais frequência neste tipo de cálculos, sendo eles a hidroxiapatite e o ácido úrico (ambos sob a forma de pó). No estudo, foram investigados vários modos de preparação destes compostos para a...

  3. Low-energy X-ray and gamma spectrometry using silicon photodiodes; Espectrometria de raios X e gama de baixa energia utilizando fotodiodos de silicio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Iran Jose Oliveira da

    2000-08-01

    The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm{sup 2} and 0,25 cm{sup 2}, thickness of the depletion ranging from 100 to 200 {mu}m and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were {sup 241} Am, {sup 109} Cd, {sup 57} Co and {sup 133} Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

  4. Estudo por espectrometria de massas de soluções de hidróxi(tosilóxi)iodobenzeno: propostas para mecanismos de desproporção

    OpenAIRE

    Vasconcelos, Ramon S.; Luiz F. Silva Jr.; Norberto P. Lopes

    2012-01-01

    STUDY BY MASS SPECTROMETRY OF SOLUTIONS OF [HYDROXY(TOSYLOXY)IODO]BENZENE: PROPOSED DISPROPORTIONATION MECHANISMS. Solutions of [hydroxy(tosyloxy)iodo]benzene (HTIB or Koser's reagent) in acetonitrile were analyzed using high resolution electrospray ionization mass spectrometry (ESI-MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) under different conditions. Several species were characterized in these analyses. Based on these data, mechanisms were proposed for the dispropo...

  5. Thallium Analysis in Environmental Samples by Inductively Coupled Plasma Mass Spectrometry; Analisis de Talio en Muestras Ambientales por Espectrometria de Masas con Fuente de Plasma de Acoplamiento Inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Higueras, I.; Fernandez, M.; Conde, E.; Gajate, A.

    2008-08-06

    Due to its high toxicity, thallium has been considered by the US Environmental Protection Agency as one of the priority pollutants to be controlled. While being a highly toxic element, thallium has been studied to a much lesser degree than other toxic elements, mainly because thallium is often undetected by classical analytical methods. Thallium is a rare and dispersed element that occurs mainly in sulfur-containing ores. Thus, it is a potential pollutant to surrounding environment, if Tl-rich mineral and/or their industrial wastes are not properly disposed. In this work an Inductively Coupled Plasma Mass Spectrometry analytical procedure has been developed in order to determine thallium in environmental solid samples and its application to the study of this element as a potential pollutant associated with natural and anthropogenic activities. The analytical procedure has been validated by the use of appropriate reference materials, and through the isotope dilution technique as a primary method of measurement. Finally, the developed procedure has been applied to several samples from a mining area, as one of the scenarios where thallium it is likely to occur. (Author) 87 refs.

  6. Development of a methodology for radionuclide impurity analysis in radiopharmaceuticals using gamma spectrometry; Desenvolvimento de uma metodologia para analise de impurezas radionuclidicas em radiofarmacos por espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Eduardo Bonfim de; Araujo, Miriam Taina Ferreira de; Delgado, Jose Ubiratan; Poledna, Roberto; Lins, Ronaldo; Leiras, Anderson; Silva, Carlos Jose da; Oliveira, Antonio Eduardo de, E-mail: bonfim@bolsista.ird.gov.br, E-mail: miriamtaina@hotmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    The LNMRI has sought to develop a methodology for the identification and accurate detection of gamma radiation impurities stations in metrological level, aiming to meet the recommendations not only of international pharmacopoeia, as well as the CNEN and ANVISA regarding the quality control can ensure patients the doses received by the practices are as low as feasible. As an initial target, it was possible to obtain an efficiency curve with uncertainty around 1% necessary to initiate future measurements of interest applied to nuclear medicine and to start the development of impurities analysis technique. (author)

  7. Determination of burnup grade of fuel plates by gamma spectrometry; Determinacao do grau de queima em elementos combustiveis tipo placa por meio de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1999-11-01

    This work describes absolute burnup measurements on spent MTR fuel elements by means of non-destructive gamma-ray spectroscopy which correlates activities of radioactive fission products with the fissioned mass of {sup 235} U. Experiments based on such method were performed at the storage pool area of the IEA-R1 research reactor. The obtained results were compared with calculational ones based on neutronics. (author) 7 refs., 6 figs., 1 tab.; e-mail: laaterre at net.ipen.br

  8. Neutron spectrometry and dosimetry by means of evolutive neural networks; Espectrometria y dosimetria de neutrones por medio de redes neuronales evolutivas

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J.M.; Martinez B, M.R.; Vega C, H.R. [UAZ, Av. Ramon Lopez Velarde Num. 801, 98000 Zacatecas (Mexico)

    2008-07-01

    The artificial neural networks and the genetic algorithms are two relatively new areas of research, which have been subject to a growing interest during the last years. Both models are inspired by the nature, however, the neural networks are interested in the learning of a single individual, which is defined as fenotypic learning, while the evolutionary algorithms are interested in the adaptation of a population to a changing environment, that which is defined as genotypic learning. Recently, the use of the technology of neural networks has been applied with success in the area of the nuclear sciences, mainly in the areas of neutron spectrometry and dosimetry. The structure (network topology), as well as the learning parameters of a neural network, are factors that contribute in a significant way with the acting of the same one, however, it has been observed that the investigators in this area, carry out the selection of the network parameters through the essay and error technique, that which produces neural networks of poor performance and low generalization capacity. From the revised sources, it has been observed that the use of the evolutionary algorithms, seen as search techniques, it has allowed him to be possible to evolve and to optimize different properties of the neural networks, just as the initialization of the synaptic weights, the network architecture or the training algorithms without the human intervention. The objective of the present work is focused in analyzing the intersection of the neural networks and the evolutionary algorithms, analyzing like it is that the same ones can be used to help in the design processes and training of a neural network, this is, in the good selection of the structural parameters and of network learning, improving its generalization capacity, in such way that the same one is able to reconstruct in an efficient way neutron spectra and to calculate equivalent doses starting from the counting rates of a Bonner sphere spectrometric system. (Author)

  9. Committed effective dose determination in cereal flours by gamma-ray spectrometry; Determinacao das doses efetivas por ingestao de farinhas de cereais atraves da espectrometria de raios gama

    Energy Technology Data Exchange (ETDEWEB)

    Scheibel, Viviane

    2006-07-01

    The health impact from radionuclides ingestion of foodstuffs was evaluated by the committed effective doses determined in commercial samples of South-Brazilian cereal flours (soy, wheat, corn, manioc, rye, oat, barley and rice flour). The radioactivity traces of {sup 228}Th, {sup 228}Ra, {sup 226}Ra, {sup 40}K, {sup 7}Be and {sup 137}Cs were measured by gamma-ray spectrometry employing a 66% relative efficiency HPGe detector. The energy resolution for the 1332.46 keV line of {sup 60}Co was 2.03 keV. The committed effective doses were calculated with the activities analyzed in the present flour samples, the foodstuff rates of consumption (Brazilian Institute of Geography and Statistics) and the ingestion dose coefficients (International Commission of Radiological Protection). The reliability median activities were verified with {chi}{sup 2} tests, assuring the fittings quality. The highest concentration levels of {sup 228}Th and {sup 40}K were 3.5 {+-} 0.4 and 1469 {+-} 17 Bq.kg{sup -1} for soy flour, respectively, with 95% of confidence level. The lower limit of detection for {sup 137}Cs ranged from 0.04 to 0.4 Bq.kg{sup -1}. The highest committed effective dose was 0.36 {mu}Sv.y{sup -1} for {sup 228}Ra in manioc flour (adults). All committed effective doses determined at the present work were lower than the UNSCEAR limits of 140 {mu}Sv.y{sup -1} and much lower than the ICRP (1991) limits of 1 mSv.y{sup -1}, for general public. There are few literature references for natural and artificial radionuclides in foodstuffs and mainly for committed effective doses. This work brings the barley flour data, which is not present at the literature and {sup 7}Be data which is not encountered in foodstuffs at the literature, besides all the other flours data information about activities and committed effective doses. (author)

  10. Application of electron ionization mass spectrometry for mulungu alkaloid analysis; Aplicacao de espectrometria de massas com ionizacao por eletron na analise de alcaloides do mulungu

    Energy Technology Data Exchange (ETDEWEB)

    Feitosa, Luis Guilherme Pereira; Guaratini, Thais; Lopes, Joao Luis Callegari; Lopes, Norberto Peporine [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Bizaro, Aline Cavalli; Silva, Denise Brentan da, E-mail: npelopes@fcfrp.usp.br [Incubadora SUPERA, Ribeirao Preto, SP (Brazil). Lychnoflora Pesquisa e Desenvolvimento em Produtos Naturais

    2012-07-01

    Erythrina verna is a medicinal plant used to calm agitation popularly known as mulungu. We purchased the barks of E. verna from a commercial producer and analyzed the alkaloid fraction of the bark by CG-MS and HRESI-MS. Five erythrinian alkaloids were identified: erysotrine, erythratidine, erythratidinone, epimer, and 11-hydroxyeritratidinone. Here we report the compound 11-hydroxyeritratidinone for the first time as a natural product. (author)

  11. Test and validation of the iterative code for the neutrons spectrometry and dosimetry: NSDUAZ; Prueba y validacion del codigo iterativo para la espectrometria y dosimetria de neutrones: NSDUAZ

    Energy Technology Data Exchange (ETDEWEB)

    Reyes H, A.; Ortiz R, J. M.; Reyes A, A.; Castaneda M, R.; Solis S, L. O.; Vega C, H. R., E-mail: alfredo_reyesh@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Lopez Velarde 801, Col. Centro, 98000 Zacatecas (Mexico)

    2014-08-15

    In this work was realized the test and validation of an iterative code for neutronic spectrometry known as Neutron Spectrometry and Dosimetry of the Universidad Autonoma de Zacatecas (NSDUAZ). This code was designed in a user graph interface, friendly and intuitive in the environment programming of LabVIEW using the iterative algorithm known as SPUNIT. The main characteristics of the program are: the automatic selection of the initial spectrum starting from the neutrons spectra catalog compiled by the International Atomic Energy Agency, the possibility to generate a report in HTML format that shows in graph and numeric way the neutrons flowing and calculates the ambient dose equivalent with base to this. To prove the designed code, the count rates of a spectrometer system of Bonner spheres were used with a detector of {sup 6}LiI(Eu) with 7 polyethylene spheres with diameter of 0, 2, 3, 5, 8, 10 and 12. The count rates measured with two neutron sources: {sup 252}Cf and {sup 239}PuBe were used to validate the code, the obtained results were compared against those obtained using the BUNKIUT code. We find that the reconstructed spectra present an error that is inside the limit reported in the literature that oscillates around 15%. Therefore, it was concluded that the designed code presents similar results to those techniques used at the present time. (Author)

  12. Performance of direct ethanol and methanol fuel cells as function of alcohol concentration applied to the anode of those cells; Desempenho de celulas a combustivel com alimentacao direta de etanol (CCADE) e celulas a combustivel com alimentacao direta de metanol (CCADM) em funcao da concentracao do alcool aplicado ao anodo destas celulas

    Energy Technology Data Exchange (ETDEWEB)

    Belchor, P.M.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Correa, J.P.; Kuhn, C.K.; Carpenter, D. [FURB -Fundacao Universidade Regional de Blumenau, SC (Brazil)

    2010-07-01

    This paper aimed to compare the performance of a CCADE and a CCADM as function of diminishing of concentration of alcohol applied top the anode of each cell. As result, reaching a diminishing the concentration of each alcohol through the mix of each one with the deionized water, one obtained a improved humidification and sensible reduction of the permeability of cationic membrane, generating a gain of performance of the functioning both cells. (author)

  13. Fuel cell: new electrocatalysts for SOFC (Solid Oxide Fuel Cells) anodes and regulation between cell performance and catalytic activity; Celula a combustivel: novos eletrocatalisadores para anodos de SOFC (Celulas a Combustivel de Oxido Solido) e correlacao entre desempenho da celula e atividade catalitica

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Aguiar, Aurinete B.; Brandao, Soraia T. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Frank, Maria Helena Troise; Campos, Michel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    Electro-catalysts were prepared using new routes. Chemical Ultrasound Deposition (CUD) method: aqueous solution of nickel nitrate and citric acid was ultrasound vaporized and deposited on heated Ytria-stabilized Zirconia (YSZ). Resin impregnation (IPR) method: nickel oxide and YSZ were mixed, added to phenolic resins, precipitated in acidic water and milled. Wet impregnation method (IMP) was used for comparison: YSZ and an aqueous solution of nickel nitrate and citric acid were mixed, followed by evaporation, drying and calcination. The catalysts were evaluated for methane steam reforming in a quartz reactor. The reactions were conducted for one hour with no significant catalytic activity loss. In reactions with 100 mg of catalyst and a mixture consisting of methane and steam (3:1), IPR catalyst showed activity higher and better stability than those by IMP. On other tests, the reform was conducted with 100 mg of catalyst and methane to steam of 10. The IPR catalyst activity was so high that the reaction approached equilibrium conditions. Anode/electrolyte/cathode units (A/E/C) were prepared with the above catalysts as follows: the anode was a catalyst porous layer; the electrolyte an YSZ dense layer; and the cathode an LSM porous layer; graphite powder formed the material porosity. The two first layers, in powder form, were put in a stainless steel cast, pressed to 4000 bars and sinterized. The cathode layer was subsequently added using tape-casting techniques followed by sintering. A/E/C units showed 40% linear contraction and porosity higher than 20%. For fuel cell tests, A/E/C was mounted in alumina plates with platinum current collectors. Unitary SOF cells were loaded with hydrogen diluted in nitrogen showing opened circuit voltage from circa 700 mV, for the CUD anode, to 350 mV, for the IPR anode. The unitary SOFC was loaded with methane for 15 minutes or longer, with no noticeable voltage loss. At 1300 K the SOFC made with IPR or IMP catalysts showed opened current voltages close to 500 mV, while CUD SOFC measured less approximately 300 mV. In conclusion, the SOFC opened current voltage might be related to the reforming activity of the electro-catalyst used as the anode. (author)

  14. O estado da arte da cromatografia associada à espectrometria de massas acoplada à espectrometria de massas na análise de compostos tóxicos em alimentos The state of the art of chromatography associated with the tandem mass spectrometry for toxic compound analyses in food

    Directory of Open Access Journals (Sweden)

    Mariza C. Chiaradia

    2008-01-01

    Full Text Available Chromatography combined with several different detection systems is one of the more used and better performing analytical tools. Chromatography with tandem mass spectrometric detection gives highly selective and sensitive analyses and permits obtaining structural information about the analites and about their molar masses. Due to these characteristics, this analytical technique is very efficient when used to detect substances at trace levels in complex matrices. In this paper we review instrumental and technical aspects of chromatography-tandem mass spectrometry and the state of the art of the technique as it is applied to analysis of toxic substances in food.

  15. Establishment of methodology for determination of {sup 93}Zr in radioactive wastes by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS); Estabelecimento de metodologia para determinacao de {sup 93}Zr em rejeitos radioativos por Espectrometria de Cintilacao Liquida (LSC) e Espectrometria de Massa com Plasma Indutivamente Acoplado (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago Cesar de

    2014-06-01

    The zirconium-93 is a long-lived pure β-particle-emitting radionuclide produced from {sup 235}U fission and from neutron activation of the stable isotope {sup 92}Zr and thus occurring as one of the radionuclides found in nuclear reactors. Due to its long half life, {sup 93}Zr is one of the radionuclides of interest for the performance of assessment studies of waste storage or disposal. Measurement of {sup 93}Zr is difficult owing to its trace level concentration and its low activity in nuclear wastes and further because its certified standards are not frequently available. The aim of this work was to develop a selective radiochemical separation methodology for the determination of {sup 93}Zr in nuclear waste and analyze it by Liquid Scintillation Counting (LSC) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). To set up the radiochemical separation procedure for zirconium, a tracer solution of {sup 95}Zr and its 724 keV γ-ray measurements by γ- spectrometry were used in order to follow the behavior of zirconium during the radiochemical separation. For the LSC technique a {sup 55}Fe solution, which is one of the major interfering measures zirconium, was used to verify the decontamination factor during the separation process. The efficiency detection for {sup 63}Ni was used to determination of {sup 93}Zr activity in the matrices analyzed. The limit of detection of the 0.05 Bq 1{sup −1} was obtained for {sup 63}Ni standard solutions by using a sample:cocktail ratio of 3:17 mL for Optiphase Hisafe 3 cocktail. For the ICP-MS technique a zirconium stable solution was used to verify the zirconium behavior and recovery during radiochemical separation and a solution of Ba, Co, Eu, Fe, Mn, Nb, Sr and Y was used to verify the decontamination factor during the separation process. A standard solution {sup 93}Nb as isotope for determining the {sup 93}Zr by ICP-MS was used for calibration and analysis. The detection limit of 0.039 ppb was obtained for the standard solution of zirconium. Then, the protocol was applied to low level waste (LLW) and intermediate level waste (ILW) from nuclear power plants. (author)

  16. Development and validation of methodology for technetium-99m radiopharmaceuticals using high performance liquid chromatography (HPLC); Desenvolvimento e validacao de metodologia para radiofarmacos de tecnecio-99m empregando cromatografia liquida de alta eficiencia (CLAE)

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Erika Vieira de

    2009-07-01

    Radiopharmaceuticals are compounds, with no pharmacological action, which have a radioisotope in their composition and are used in Nuclear Medicine for diagnosis and therapy of several diseases. In this work, the development and validation of an analytical method for {sup 99}mTc-HSA, {sup 99}mTc-EC, {sup 99}mTc-ECD and {sup 99}mTc-Sestamibi radiopharmaceuticals and for some raw materials were carried out by high performance liquid chromatography (HPLC). The analyses were performed in a Shimadzu HPLC equipment, LC-20AT Prominence model. Some impurities were identified by the addition of a reference standard substance. Validation of the method was carried out according to the criteria defined in RE n. 899/2003 of the National Sanitary Agency (ANVISA). The results for robustness of the method showed that it is necessary to control flow rate conditions, sample volume, pH of the mobile phase and temperature of the oven. The analytical curves were linear in the concentration ranges, with linear correlation coefficients (r{sup 2}) above 0.9995. The results for precision, accuracy and recovery showed values in the range of 0.07-4.78%, 95.38-106.50% and 94.40-100.95%, respectively. The detection limits and quantification limits varied from 0.27 to 5.77 {mu}g mL{sup -1} and 0.90 to 19.23 {mu}g mL{sup -1}, respectively. The values for HAS, EC, ECD and MIBI in the lyophilized reagents were 8.95; 0.485; 0.986 and 0.974 mg L-1, respectively. The mean radiochemical purity for {sup 99}mTc-HSA, {sup 99}mTc-EC, {sup 99}mTc-ECD and {sup 99}mTc-Sestamibi was (97.28 {+-} 0.09)%, (98.96 {+-} 0.03)%, (98.96 {+-} 0.03)% and (98.07 {+-} 0.01)%, respectively. All the parameters recommended by ANVISA were evaluated and the results are below the established limits. (author)

  17. Study of a 4{pi}{beta}-{gamma} coincidence system for absolute radionuclide activity measurement using plastic scintillators; Estudo de um sistema de coincidencias 4{pi}{beta}-{gamma} para a medida absoluta de atividade de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Piuvezam Filho, Helio

    2007-07-01

    The present work was intended to study a coincidence system 4{pi}(PS){beta}-{gamma} for absolute activity measurement using plastic scintillators in 4{pi} geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4{pi}(PS){beta}-{gamma} and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

  18. Desenvolvimento de sistemas líquido-cristalinos empregando silicone fluido de co-polímero glicol e poliéter funcional siloxano Development of liquid-crystalline systems using silicon glycol copolymer and polyether functional siloxane

    Directory of Open Access Journals (Sweden)

    Marlus Chorilli

    2009-01-01

    Full Text Available For the construction of the phase diagrams, the method of the aqueous titration was used. There were prepared 5 ternary diagrams, varying the surfactant and the oil phase. The liquid-crystalline phases were identified by polarized light microscopy. The formulations prepared with silicon glycol copolymer, polyether functional siloxane (PFS and water (S1 and with diisopropyl adipate, PFS and water (S4 presented liquid-crystalline phases with lamellar arrangement. Moreover, after 15 days in hot oven (37 ºC, the formulations presented hexagonal arrangement, evidencing the influence of the temperature in the organization of the system.

  19. O desenvolvimento embrionário da Piapara, Leporinus elongatus (Pisces, Anostomidae, utilizando técnicas de histologia, microscopia eletrônica de varredura e imunológicas empregando marcadores ósseos

    Directory of Open Access Journals (Sweden)

    Erika Z. Sousa

    2014-12-01

    Full Text Available Resumo O desenvolvimento embrionário dos peixes é de grande importância para a piscicultura e na reintrodução de espécies ameaçadas de extinção em seus ambientes, e seu conhecimento constitui uma importante maneira para minimizar doenças e mortalidades dessas espécies. Com o auxílio de técnicas como a Microscopia Eletrônica de Varredura (MEV e a imuno-histoquimica para identificar proteínas ósseas, foi possível avaliar as fases de desenvolvimento com mais riqueza de detalhes, facilitando a compreensão de hábitos e da biologia da espécie. Neste trabalho pudemos observar a ontogenia e osteogênese da Piapara (Leporinus elongatus, desde a fecundação até a fase juvenil, sendo evidenciadas estruturas importantes como o tamanho do vitelo, essencial para a nutrição do embrião; o fechamento do blastóporo, evento principal da embriogênese, que indica as taxas de fertilização; a metamorfose, que indica a formação dos primeiros e principais órgãos do animal e a formação de sua estrutura óssea. As Proteínas Ósseas Morfogenéticas (BMP-2 e BMP-4, moléculas essenciais reguladoras no desenvolvimento embrionário e na formação óssea, foram observadas apenas no estádio larval até o período juvenil, não sendo evidenciadas nos estágios anteriores. Os resultados desse trabalho trouxeram novas informações quanto à biologia do desenvolvimento dessa espécie, que certamente poderão auxiliar no aprimoramento de técnicas reprodutivas visando uma melhora na sua produção seja para fins comerciais ou de repovoamento.

  20. Determinação turbidimétrica de metilbrometo de homatropina em formulações farmacêuticas empregando um sistema de análise por injeção em fluxo

    Directory of Open Access Journals (Sweden)

    Larissa S. Canaes

    2006-12-01

    Full Text Available A flow injection turbidimetric procedure exploiting merging zones is proposed for determining homatropine methylbromide (HMB in pharmaceutical preparations. The determination is based on the precipitation reaction of homatropine methylbromide with AgNO3 solution to form a precipitate, which was measured at 410 nm. The analytical curve was linear in the HMB concentration range from 8.0x10-4 to 1.7x10-3 mol L-1, with a detection limit of 9.5x10-5 mol L-1. The recoveries ranged from 94.9 to 104 %, the sampling frequency was 75 h-1 and relative standard deviations were smaller than 2.0 % for solutions containing 1.2x10-3 and 1.5x10-3 mol L-1 HMB (n=10. The results obtained for commercial formulations using the FIA procedure were in good agreement with those obtained by using a comparative method (r= 0.9983.

  1. Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos

    Energy Technology Data Exchange (ETDEWEB)

    Baccarelli, Aida Maria

    2003-07-01

    The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

  2. Otimização da esterificação de ácido hexanóico com n-butanol empregando lipase (Termomyces lanuginosus imobilizada em gelatina

    Directory of Open Access Journals (Sweden)

    Everton Skoronski

    2013-01-01

    Full Text Available The application of Lipozyme (Termomyces lanuginosus immobilized in gelatin gel in aliphatic ester synthesis was investigated taking the esterification of hexanoic acid with n-butanol as a model reaction. Conditions were optimized by factorial design and the highest conversion was obtained under the following conditions: molar ratio alcohol: acid of 2:1, reaction time of 48 h and biocatalyst weight of 7.0 g. Under these conditions the esterification yield was around 98 %. The operational stability of the immobilized lipase was assessed and results showed that after 12 batch runs, the enzyme showed no significant loss of activity.

  3. Modelos de regressão multivariada empregando seleção de intervalos para a quantificação do biodiesel em blendas biodiesel/diesel

    Directory of Open Access Journals (Sweden)

    Marco Flôres Ferrão

    2010-01-01

    Full Text Available No presente trabalho foram analisados e comparados modelos de regressão multivariados por mínimos quadrados parciais porintervalo (iPLS e por mínimos quadrados parciais por exclusão (biPLS que selecionaram regiões do espectro mais adequadas,retirando informações não relevantes e otimizando o modelo de calibração, a fim de determinar a concentração de biodiesel emblendas de biodiesel/diesel a partir de dados obtidos por espectroscopia no infravermelho por reflectância total atenuada (HATRFTIR.Foram utilizadas 45 amostras de blendas biodiesel/diesel com concentrações de 8 a 30% de biodiesel e os espectros foramadquiridos em dois distintos espectrofotômetros e misturados aleatoriamente para a realização dos modelos, onde foram construídosmodelos para calibração utilizando 2/3 dos espectros das amostras obtendo assim os valores de RMSECV, e o restante dos espectrosforam empregados no conjunto de previsão, obtendo então os valores de RMSEP. Os dados espectrais foram autoescalados (AUTOou centrados na média (MEAN, com ou sem o emprego da correção multiplicativa de sinal (MSC. A utilização dos métodos deseleção das faixas espectrais aplicados aos espectros por ATR se mostrou viável para a quantificação do biodiesel nas blendas, sendoque a utilização da espectroscopia no infravermelho apresenta vantagens como à necessidade de pequena quantidade de amostra ebaixo tempo de análise, além de ser um procedimento não destrutivo e não gerador de resíduos, otimizando assim o processo emquestão.Abstract In the present work multivariate regressionmodels using interval partial least square (iPLS and backwardinterval partial least square (biPLS had been analyzed andcompared. iPLS and biPLS models had been developed todetermine the concentration of biodiesel in blends ofbiodiesel/diesel using infrared spectroscopy signals. 45samples with concentrations in range 8-30% of biodiesel, andtwo distinct spectrophotometers were used. Both thetechniques (iPLS and biPLS using the data obtained byHATR-FTIR if had shown promising to develop simpler,faster and non-destructive methodologies for the biodieseldetermination in commercial blends.

  4. Sistema automático para determinação seqüencial de cianeto livre e total empregando eletrodo tubular íon-seletivo de membrana homogênea

    Directory of Open Access Journals (Sweden)

    Marin Maria Angélica Bonadiman

    2000-01-01

    Full Text Available This study presents an automated system for potentiometric determination of free and total cyanide which employs a homogeneous membrane tubular ion-selective electrode. After the electrode is assembled, it is connected to a system composed of 3 three-way solenoid valves, sample line, carrier line, acid stream, and gas diffusion chamber. A Turbo Pascal® computer program, developed specifically for this task, automatically performs all the steps involved in data acquisition and processing. The proposed analytical procedure offers operational simplicity, since detection is performed by a tubular electrode, whose assembly is fast and easy. The system has shown reproducibility (r.s.d. < 0.5%, n=6 and high speed (30 readings/hour; it is efficient for determination of free and total cyanide in waste waters of starch processing plants. The detection limit was 1.2x10-5 and 1.5x10-5 mol L-1, for determination of free and total cyanide, respectively. The linear response range was between 1.2x10-5 and 1.0x10-2 mol L-1 for free cyanide and between 1.5x10-5 and 1.0x10-2 for total cyanide.

  5. Análise screening de vinhos empregando um analisador fluxo-batelada, espectroscopia UV-VIS e quimiometria Screening analysis of wines using flow-batch analyzer, UV-VIS spectroscopy and chemometrics

    Directory of Open Access Journals (Sweden)

    Jaqueline Azevedo Nascimento

    2010-01-01

    Full Text Available A simple, robust, versatile, high analytical frequency method was proposed to check if a sample of wine is within the range of standards set by the manufacturer, using the UV-VIS spectroscopy, multivariate analysis and a flow-batch analyzer. Two hundred and fifty-two samples of wines were analyzed. The results from the application of Hierachical Cluster Analysis (HCA to the matrix of the data involving all samples show the formation of fifteen types of wine. A Soft Independent Modelling of Class Analogy (SIMCA model was constructed and used to classify the samples of the overall forecast. As a result, it is observed that the prediction was performed with a success rate of 99.2% for a confidence level of 95%. This shows that the proposed methodology can be used as an effective tool for classifying of samples of wines.

  6. Cartas de controle multivariadas para o monitoramento simultâneo do teor de isoniazida e rifampicina em uma formulação farmacêutica empregando a espectroscopia no infravermelho próximo

    OpenAIRE

    2014-01-01

    O controle estatístico de processos é uma estratégia que tem sido cada vez mais utilizada para o monitoramento on-line de processos industrias, no qual a principal ferramenta utilizada são as cartas de controle, que podem ser univariadas ou multivariadas, de acordo com o número de variáveis envolvidas no monitoramento. Basicamente, as cartas de controle são gráficos estatísticos que possuem uma faixa de tolerância limitada pelas linhas superior e inferior, calculadas com bas...

  7. Difusão de contaminantes em condições de vento fraco empregando um modelo estocástico Lagrangeano Difusion of contaminants in low wind conditions employing a Lagrangian stochastic model

    Directory of Open Access Journals (Sweden)

    Andréa Ucker Timm

    2009-09-01

    Full Text Available Um modelo estocástico Lagrangeano é utilizado para simular a dispersão e o transporte de contaminantes, sob condições estáveis, com velocidade do vento fraco, no experimento traçante realizado no Idaho National Engineering Laboratory (INEL. Neste trabalho é testada uma nova parametrização dos parâmetros que representam as freqüências associadas ao fenômeno de meandro do vento, presentes nas equações de Langevin para as componentes do vento horizontal. Esta nova parametrização é descrita em termos de uma quantidade adimensional que controla a freqüência de oscilação de meandro do vento e da escala de tempo, associada às estruturas coerentes em uma turbulência bem desenvolvida. As simulações demonstram que o modelo Lagrangeano considerado, incorporando esta nova parametrização, reproduz corretamente a difusão de escalares passivos em uma camada limite atmosférica estável com velocidade do vento fraco.A Lagrangian stochastic particle model is utilized to simulate the dispersion and the transport of contaminants under low wind stable conditions in the tracer experiment carried in the Idaho National Engineering Laboratory (INEL. In this work a new parameterization for the parameters representing the frequencies associated to the meandering phenomenon is tested. The new parameterization is expressed in terms of a non-dimensional quantity that controls the frequencies of the meandering oscillation and of the time scale associated to a coherent structure in a fully developed turbulence. The simulations show that the considered Lagrangian model, incorporating this new parameterization, reproduces correctly the diffusion of passive scalars in a low wind speed stable atmospheric boundary layer.

  8. Biological control of fire blight in pear orchards with a formulation of Pantoea agglomerans strain Eh 24 Controle biológico de fire blight em pereiras empregando uma formulação de Pantoea agglomerans Eh 24

    Directory of Open Access Journals (Sweden)

    Hatice Özaktan

    2004-09-01

    Full Text Available Biological control by using epiphytic bacteria against Erwinia amylovora has been considered as an alternative method for controlling the disease. Talc-based formulation of Pantoea agglomerans strain Eh-24 was applied at 30% and 100% bloom on two pear orchards which were selected from different locations in the Aegean Region in Turkey. Pear orchard trials were replicated for two years (1999 and 2000 in each place. Talc-based formulation of P. agglomerans strain Eh-24 was sprayed on pear trees which were naturally infected with E. amylovora. In the orchard trials conducted in 1999 and 2000, talc-based formulation of P. agglomerans strain Eh-24 reduced the percentage of blighted blossoms on pear orchards by 63% to 76%, approximately. Copper oxychloride+maneb was less effective in reducing the incidence of blossom infection by E. amylovora in each pear orchard than the bioformulation treatment. P. agglomerans strain Eh-24 labelled with StrR+ was applied at 30% and 100% bloom to monitor the colonization and population dynamics of P. agglomerans on pear blossoms. The population size of P. agglomerans strain Eh-24 strR+ on pear blossoms increased from 2x10(4 to 1.3x10(6 cfu per blossom over 18 days.Controle biológico de Erwinia amylovora através do uso de bactérias epifíticas tem sido considerado um método alternativo para o controle de "fire blight". Uma formulação de Pantoea agglomerans Eh 24 em talco foi utilizada em pereiras a 30% e a 100% de floração, em duas plantações selecionadas na região Aegean da Turquia. Os experimentos foram repetidos duas vezes (1999 e 2000 em cada plantação. A formulação de P. agglomerans foi aspergida nas pereiras naturalmente infectadas com E. amylovora. Nos experimentos de 1999 e 2000, a redução da porcentagem de ocorrência de "fire blight" foi reduzida aproximadamente em 63% e em 76%, respectivamente. Oxicloreto de cobre + maneb foi menos eficiente na redução da infecção por E. amylovora do que o tratamento com a bioformulação. P. agglomerans Eh 24 marcada com StrR+ foi aplicada a 30% e a 100% de floração para monitorar a colonização e a dinâmica da população de P. agglomerans nos brotos das pereiras. Após 18 dias, a população de P. agglomerans aumentou de 2x10(4 para 1,3 x 10(6 UFC/broto.

  9. Comparative growth of trichoderma strains in different nutritional sources, using bioscreen c automated system Crescimento de linhagens de Trichoderma em diferentes fontes nutricionais, empregando o sistema automatizado Bioscreen C.

    Directory of Open Access Journals (Sweden)

    Bianca Caroline Rossi-Rodrigues

    2009-06-01

    Full Text Available Trichoderma is one of the fungi genera that produce important metabolites for industry. The growth of these organisms is a consequence of the nutritional sources used as also of the physical conditions employed to cultivate them. In this work, the automated Bioscreen C system was used to evaluate the influence of different nutritional sources on the growth of Trichoderma strains (T. hamatum, T. harzianum, T. viride, and T. longibrachiatum isolated from the soil in the Juréia-Itatins Ecological Station (JIES, São Paulo State - Brazil.The cultures were grown in liquid culture media containing different carbon- (2%; w/v and nitrogen (1%; w/v sources at 28ºC, pH 6.5, and agitated at 150 rpm for 72 h. The results showed, as expected, that glucose is superior to sucrose as a growth-stimulating carbon source in the Trichoderma strains studied, while yeast extract and tryptone were good growth-stimulating nitrogen sources in the cultivation of T. hamatum and T. harzianum.Trichoderma é um dos gêneros de fungos produtores de metabólitos de interesse industrial. O crescimento destes organismos é conseqüência das fontes nutricionais utilizadas, juntamente com as condições físicas de cultivo. Neste trabalho, o sistema automatizado Bioscreen C foi utilizado para avaliar a influência de diferentes fontes nutricionais sobre o crescimento de linhagens de Trichoderma (T. hamatum, T. harzianum, T. viride e T. longibrachiatum isoladas do solo da Estação Ecológica da Juréia-Itatins (JIES, São Paulo - Brasil. Os cultivos foram feitos em meios líquidos de cultura contendo diferentes fontes de carbono (2%; w / v e nitrogênio (1%; w / v a 28ºC, pH 6,5 e agitados a 150 rpm durante 72 h. Os resultados mostraram, conforme esperado, que a glicose é melhor do que a sacarose como fonte de carbono indutora de crescimento das linhagens de Trichoderma testadas, enquanto que, o extrato de leveduras e a triptona foram boas fontes de nitrogênio indutoras de crescimento para os cultivos de T. hamatum e T. harzianum.

  10. Monitoring of pipeline hydrostatic testing with artificial flaws applying acoustic emission and ultra-sonic techniques; Monitoracao de teste hidrostatico de tubos com descontinuidades artificiais empregando as tecnicas de emissao acustica e ultra-som

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sergio Damasceno [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2003-07-01

    Charts and parameters used to perform and analyzing the acoustic emission data collected during the hydrostatic test in pipe samples build in API XL 60 with 20 inches of diameter and 14 millimeters of thickness are shown. These pipes had internal and external artificial flaws done by electro-erosion process with aspect ratio 1 x 20. A relationship between acoustic emission results, ultrasound and J-Integral were established using the applied pressurization sequence. Characteristics values of acoustic emission signals were shown as a criteria of field tests. (author)

  11. Sobre os estudos metabólicos de fármacos empregando-se atividade enzimática de CYP450 visando-se estabelecer correlações entre estrutura e atividade

    OpenAIRE

    Renato de Lima Bauab

    2011-01-01

    A Química Medicinal é ciência multidisciplinar com ação direta sobre conhecimentos específicos focalizando Química, Biologia, Medicina, Fisiologia, entre outras áreas de estudos no domínio fundamental e tecnológico. Esta ciência atua ainda entre várias interfaces científicas tais como a Bioquímica, Biofísica, Biologia Molecular, Química Biológica e outras. A investigação no metabolismo de fármacos é a primeira e essencial fase na moderna farmacologia, uma vez que os parâmetros Farmacocinétic...

  12. Evaluation of inflammatory processes in temporomandibular joint employing technetium-99m-labelled autologous leukocytes in an animal model; Avaliacao de processos inflamatorios na articulacao temporomandibular empregando leucocitos autologos marcados com tecnecio-99m em modelo animal

    Energy Technology Data Exchange (ETDEWEB)

    Brasileiro, Claudia Borges [Centro Universitario Newton Paiva, Belo Horizonte, MG (Brazil)]. E-mail: claudiabb.prof@newtonpaiva.br; cbbrasileiro@bol.com.br; Cardoso, Valbert Nascimento; Ruckert, Bianca [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia; Campos, Tarcisio Passos Ribeiro de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear

    2006-07-15

    Objective: the present study was aimed at identifying temporomandibular joint inflammatory processes employing technetium-99m hexamethyl propylene amine oxime (99mTc-HMPAO)-labeled autonomous leukocytes. Materials and methods: we have utilized an experimental model of arthritis induction in ten adult male New Zealand rabbits by means of ovalbumin intra-articular injection into each left temporomandibular joint. For control purposes, saline solution was injected. After leukocytes radiolabeling with 99mTc-HMPAO and injection into rabbits, scintigraphic images were obtained. Results: a higher 99mTc-HMPAO-leukocytes uptake was observed in left temporomandibular joint in comparison with the contralateral joint. Wilcoxon non-parametric test was applied for statistical analysis. There was a statistically significant difference between counts of radioactivity per minute in the inflamed joint and the contralateral one (p = 0.0073). Conclusion: the method employing 99mTc-HMPAO-labelled autologous leukocytes allows an early and accurate detection of inflammatory processes, contributing to the adoption of a therapeutic conduct for patients before structural alterations have occurred. (author)

  13. AVALIAÇÃO DO CUSTO DE CONSTRUÇÃO DE UMA ESTRUTURA DE PAVIMENTO EMPREGANDO AGREGADO RECICLADO DE RCD (DOI:10.5216/reec.V10i1.31557

    Directory of Open Access Journals (Sweden)

    Adriana Goulart Santos

    2015-07-01

    Full Text Available RESUMO: O uso de agregados reciclados provenientes de resíduos de construções e demolições (RCD tem sido vistos como uma alternativa de reduzir a disposição inadequada destes materiais no meio ambiente, como também reduzir os custos de pavimentação. Neste contexto, o presente artigo tem como objetivo dimensionar, para as vias de tráfego intenso da cidade de Joinville-SC, uma estrutura de pavimento usando em sua composição misturas de solo e agregado reciclado e avaliar o seu custo de construção. Para isso, foram realizados ensaios de caracterização física do agregado reciclado e do solo. A partir daí foram dosadas duas misturas com teores diferentes de materiais e avaliado as suas respectivas resistências mecânicas. Com os resultados obtidos constatou-se que as misturas avaliadas podem ser empregadas na construção de camadas de sub-base. Verificou-se que houve uma redução de 8,8% nos custos de construção de pavimentos usando a mistura de solo-agregado reciclado. Por fim, o estudo apresenta que o uso do agregado reciclado pode ser uma alternativa econômica e tecnicamente viável para a área rodoviária, pois o dimensionamento mostrou que esse material pode ser utilizado para compor as camadas nobres de um pavimento. ABSTRACT: The use of recycled aggregate from construction and demolition waste has been seen as an alternative to reduce the improper disposal of these materials in the environment, and also reduce the cost of pavements construction. In this context, the present paper aims to pavement designer to the urban roads of the city of Joinville-SC, a structure of pavement that in its composition is used mixtures of soil and recycled aggregate and evaluation it costs of construction. For this, were made physical characterization tests for the recycled aggregate and the soil. Thereafter two mixtures were measured with different levels of materials and analyzed their respective mechanical behaviors. With the results it was verified that mixtures may be employed only in the construction of sub-base layer. It was noted that there was a reduction in the costs of pavements construction using the mixture of soil- recycled aggregate. Finally, the study present that the use of recycled aggregate can be a cost-effective alternative and technically feasible for the road area, because the pavement designer showed that this material can be used to compose the noble layers of a pavement.

  14. OTIMIZAÇÃO DO PROCESSO DE PRODUÇÃO DE TIQUIRA EMPREGANDO ENZIMAS COMERCIAIS E FUNGOS ISOLADOS A PARTIR DOS BEIJUS UTILIZADOS NO MÉTODO TRADICIONAL

    OpenAIRE

    2013-01-01

    A tiquira é uma bebida típica do Maranhão (Brasil), obtida a partir de mandioca (Manihot esculenta, Crantz.), sua produção se concentra em diversos municípios do Estado, através de um processo artesanal, bastante primitivo, no qual a conversão do amido de mandioca em açúcares fermentescíveis é feita por bolores nativos que surgem sobre os beijus de massa de mandioca, onde as cepas são colhidas ao acaso. A fermentação alcoólica também é feita por leveduras selvagens. Tem sua comercialização pr...

  15. Development of internal dosimetry protocols using the code MCNPx and voxelized phantoms of Reference of ICRP 110; Desenvolvimento de protocolos de dosimetria interna empregando o codigo MCNPx e fantomas voxelizados de referencia da ICRP 110

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, B.M.; Fonseca, T.C.F., E-mail: bmm@cdtn.br [Centro de esenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Trindade, B.M.; Campos, T.P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-04-01

    The objective of this work was to perform internal dosimetry calculations for {sup 18}F-FDG employing the MCNPx code and ICRP 110 voxelized reference phantoms (RCP{sub A}F and RCP{sub A}M). The methodologies developed and validated here represent protocols of internal dosimetry holding a better anthropomorphic and anthropometric representation of the human model in which heterogeneous distributions of the emissions can be adopted, useful in the study of new radiopharmaceuticals and internal contamination cases. The reference phantoms were implemented to run on MCNPx. Biodistribution data of {sup 18}F-FDG radiopharmaceutical provided in ICRP 128 were used in the simulations. The organs average absorbed doses and the effective doses were calculated for each model. The values obtained were compared with two reference works available in the literature for validation purposes. The means of the difference of our values and Zankl et al., 2012 reference values were -0.3% for RCP{sub A}M and -0.4% for RCP{sub A}F. Considering Hadid et al., 2013 reference values, the means of the deviation were -2.9% and -2.2% for RCP{sub A}M and RCP{sub A}F respectively. No statistically significant differences were observed (p <0.01) between the reference values and the values calculated by the internal dosimetry protocols developed by our group. Considering the {sup 18}F-FDG validation study performed in this work, the internal dosimetry protocols developed by our group have produced suitable dosimetry data. (author)

  16. Determinação simultânea de topiramato, carbamazepina, fenitoína e fenobarbital em plasma empregando cromatografia a gás com detector de nitrogênio e fósforo

    Directory of Open Access Journals (Sweden)

    Roberta Zilles Hahn

    2013-01-01

    Full Text Available Topiramate and the other frequently co-administered antiepileptic drugs carbamazepine, phenytoin and phenobarbital were determined in 100 µL plasma samples by gas chromatography with nitrogen phosphorus detection (GC-NPD, after a one-step liquid-liquid extraction with ethyl acetate, followed by flash methylation with trimethylphenylammonium hydroxide. Total chromatographic run time was 12.5 min. Intra-assay and inter-assay precision was 2.5-7.3% and 1.6-5.2%, respectively. Accuracy was 100.1-104.2%. The limit of quantitation was 1 µg mL-1 for all analytes, proving suitable for routine application in therapeutic drug monitoring of antiepileptic drugs.

  17. High power factor, fixed frequency, three-phase AC/CC converter which uses a single power processing stage; Conversor CA/CC, trifasico, com alto fator de potencia, frequencia fixa, empregando um unico estagio de processamento de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Davila, Jose Gregorio Contreras

    1993-11-01

    This paper introduces a new switching mode power supply with the following properties: zero-voltage switching, pulse-width modulation at constant frequency, three-phase input with power factor and low input current distortion, using a simple power stage. The converter is designed in a manner that the input current harmonic content is reduced naturally. Circuit-operation, theoretical analysis, simulation, design procedure and example are presented. A laboratory prototype rated at 3 kW and operating at 100 Khz, has been fabricated and tested successfully. (author) 15 refs., 75 figs.

  18. Correção de aneurisma de ventrículo esquerdo em paciente chagásico empregando prótese de pericárdio bovino

    Directory of Open Access Journals (Sweden)

    HERRERA Cassius Borsato

    2000-01-01

    Full Text Available Os autores descrevem a correção cirúrgica de aneurisma do ventrículo esquerdo em paciente chagásica que apresentava insuficiência cardíaca. Usando uma prótese de pericárdio bovino foi possível reconstruir a parede aneurismática do ventrículo esquerdo, obtendo-se acentuada redução dos sintomas. Assim, acreditam que os benefícios já adquiridos neste tipo de operação em pacientes com aneurismas de ventrículo esquerdo de etiologia isquêmica, podem ser estendidos aos pacientes chagásicos

  19. Determinação de isotermas de adsorção de Saccharomyces cerevisiae empregando acetato e sulfato de cádmio Cadmium adsorption isotherms by Saccharomyces cerevisiae using cadmiun acetate and sulphate

    Directory of Open Access Journals (Sweden)

    Silvana Albertini

    2007-06-01

    Full Text Available Para determinar as isotermas de adsorção de cádmio por Saccharomyces cerevisiae, foram utilizados os sais acetato e sulfato de cádmio, nas concentrações de 5; 10; 20; 40; 60; 80 e 100 mg.L-1. A biomassa foi produzida a partir de uma cultura "starter" de Saccharomyces cerevisiae IZ 1904. Após o contato de 16 horas entre o microrganismo em estudo e as soluções teste, a biomassa foi separada por centrifugação e o teor de cádmio residual foi determinado por espectrofotometria de absorção atômica diretamente no sobrenadante. Os dois sais testados demonstraram acúmulo crescente do metal nas concentrações de 5; 10; 20 e 40 mg.L-1. Porém, nas concentrações de 60; 80 e 100 mg.L-1, foi observado um acúmulo decrescente do metal, mostrando assim danos da parede celular, nem sempre evidenciados em nível de membrana citoplasmática, visualizados por microscopia eletrônica de varredura.To determine the isotherms of the adsorption of cadmium for Saccharomyces cerevisiae, acetate and sulphate salts were used at the concentrations of 5, 10, 20, 40, 60, 80, and 100 mg.L-1. The biomass was produced from a starter culture of Saccharomyces cerevisiae IZ 1904. After the contact of 16 hours among the microrganism study and the solution-test, the biomass was separated by a centrifugation and the cadmium residue content was determined directly in the supernatant by atomic absorption spectrophotometry. For the two salts which were used, a growing accumulation of cadmium was observed at concentrations of 5, 10, 20, and 40 mg.L-1. In the concentrations of 60; 80 and 100 mg.L-1 a decrease in the accumulation of the metal was observed, showing damage to the cellular wall, not always observed at the membrane citoplasmatic's level, visualized by a scanning electron microscopy.

  20. Estudo e caracterização da zeólita OFF Tipo T empregando diferentes fontes de silício Study and characterization of zeolite Offretite Type T employing differents silicon sources

    Directory of Open Access Journals (Sweden)

    Alessandra Caovilla

    2009-01-01

    Full Text Available Offretite T zeolite was synthesized using different source of Si (Ludox AS-30, Ludox LS-30 and Aerosil 200 Degussa. The obtained materials were characterized by different complementary techniques: XRD, textural analysis by N2 adsorption, IV, SEM and chemistry analysis. This zeolite has an intermediary structure between offretite and erionite zeolites. In all experiments offretite T phase was obtained. Offretite phase presenting better crystalility are obtained in synthesis with stirring and employing aerosil as silicon source. This zeolite presents a potencial application as catalyst for hydroisodewaxing process.

  1. Síntese do butirato de n-butila empregando lipase microbiana imobilizada em copolímero de estireno-divinilbenzeno Synthesis of butyl butyrate by microbial lipase immobilized onto styrene-divinylbenzene copolymer

    Directory of Open Access Journals (Sweden)

    Pedro Carlos de Oliveira

    2000-10-01

    Full Text Available This work investigates the reaction parameters of an immobilized lipase in the esterification reaction of n-butanol and butyric acid. Microbial lipase from Candida rugosa was immobilized onto styrene-divinylbenzene copolymer (STY-DVB and subsequently introduced in an organic medium containing substrates in appropriate concentrations. Heptane was selected as solvent on the basis of its compatibility with the resin and the enzyme. The influence of molar ratio of acid to alcohol, amount of immobilized lipase and temperature on the butyl butyrate formation was determined. The results were compared with those achieved with free lipase and Lipozyme (commercially immobilized lipase under the same operational conditions.

  2. Indirect flow injection determination of N-acetyl-L-cysteine using cerium(IV) and ferroin; Determinacao indireta de N-acetil-L-cisteina por injecao em fluxo empregando Ce(IV) e ferroina

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Heberth Juliano; Fatibello-Filho, Orlando [Sao Carlos Univ., SP (Brazil). Dept. de Quimica]. E-mail: bello@dq.ufscar.br

    2005-09-15

    An indirect flow injection spectrophotometric procedure is proposed for the determination of N-acetyl-L-cysteine in pharmaceutical formulations. In this system, ferroin ([Fe(II)-(fen){sub 2}]{sup 2+}) in excess, with a strong absorption at 500 nm, is oxidized by cerium(IV) yielding cerium(III) and [Fe(III)-(fen){sub 2}]{sup 3+} (colorless), thus producing a baseline. When N-acetyl-L-cysteine solution is introduced into the flow injection system, it reacts with cerium(IV) increasing the analytical signal in proportion to the drug concentration. Under optimal experimental conditions, the linearity of the analytical curve for N-acetyl-L-cysteine ranged from 6.5x10{sup -6} to 1.3x10{sup -4} mol L{sup -1}. The detection limit was 5.0x10{sup -6} mol L{sup -1}and recoveries between 98.0 and 106% were obtained. The sampling frequency was 60 determinations per hour and the RSD was smaller than 1.4% for 2.2x10{sup -5} mol L{sup -1} N-acetyl-L-cysteine. (author)

  3. Determinação espectrofotométrica de ácido ascórbico em fármacos empregando amostragem binária em fluxo

    Directory of Open Access Journals (Sweden)

    Paim Ana Paula S.

    1998-01-01

    Full Text Available A flow system procedure for spectrophotometric determination of ascorbic acid in drugs based on [Fe3+(SCN-n]+3-n complex decomposition by reduction is described. The flow network was constituted by a set of three-way solenoid valves, controlled by a microcomputer running a software wrote in QuickBasic 4.5 language. The feasibility of the procedure was ascertained by determining ascorbic acid in drug samples with mass ranging from 0.0018 up to 0.0180 g. The results showed an agreement of about 7% when compared with recommended method. Other profitable features such as a standard deviation of 1.5% (n = 7 and a throughput of 120 determinations per hour was also achieved.

  4. Sistema em fluxo para determinação espectrofotométrica de uréia em plasma de sangue animal empregando leguminosa como fonte natural da enzima urease

    Directory of Open Access Journals (Sweden)

    Luca Gilmara C.

    2001-01-01

    Full Text Available A spectrophotometric flow injection analysis (FIA procedure employing natural urease enzyme source for the determination of urea in animal blood plasma was developed. Among leguminous plants used in the Brazilian agriculture, the Cajanus cajan specie was selected as urease source considering its efficiency and availability. A minicolumn was filled with leguminous fragments and coupled to the FIA manifold, where urea was on-line converted to ammonium ions and subsequently it was quantified by spectrophotometry. The system was employed to determine urea in animal plasma samples without any prior treatment. Accuracy was assessed by comparison results with those obtained employing the official procedure and no significant difference at 90 % confidence level was observed. Other profitable features such as an analytical throughput of 30 determinations per hour, a reagent consumption of 19.2 mg sodium salicylate, 0.5 mg sodium hipochloride and a relative standard deviation of 1.4 % (n= 12 were also obtained.

  5. OTIMIZAÇÃO DO PROCESSO DE INSERÇÃO AUTOMÁTICA DE COMPONENTES ELETRÔNICOS EMPREGANDO A TÉCNICA DE TIMES ASSÍNCRONOS

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    Cesar Scarpini Rabak

    2001-06-01

    Full Text Available Este trabalho apresenta um sistema computacional que busca otimizar o processo de inserção automática de componentes eletrônicos com a máquina Panasert AVK, baseada na técnica de times assíncronos (A-Teams. É feita a formulação do problema de inserção e apresentada a arquitetura do sistema. Por último, são apresentados os resultados obtidos e conclusões inferidas, demonstrando a viabilidade da utilização desta técnica nesta classe de problemas.This paper presents a computational system which aims to optimize the automatic insertion process of electronic components with the Panasert AVK machine, based on asynchronous teams (A-Teams. A formulation of the insertion problem is proposed and the architecture of the system is presented. Finally, the obtained results and inferred conclusions are presented, showing the viability of this technique when applied in this class of problems.

  6. CUSTO COMPARATIVO DE CONTROLE À FORMIGA CORTADEIRA Atta sexdens rubropilosa Forel 1908, EMPREGANDO-SE ISCAS GRANULADAS COMERCIAIS E UMA ISCA EXPERIMENTAL COMPARATIVE COST CONTROL OF Atta sexdens rubropilosa FOREL 1908 USING COMMERCIAL GRAIN BAITS AND AN EXPERIMENTAL BAIT

    Directory of Open Access Journals (Sweden)

    Antônio Lopes da Silva

    2007-09-01

    Full Text Available

    Realizou-se um experimento de controle à formiga cortadeira Atta sexdens rubropilosa FOREL 1908, nos campos da Universidade Federal de Goiás (dezembro de 1972, com a finalidade de comparar o custo de controle por sauveiro, utilizando-se uma isca granulada experimental “EAV-041-A” idealizada pelo autor, com outras iscas existentes no mercado. Foram realizados 4 tratamentos (Mirex, Isca Shell, EAV-041-A e Agroceres na base de 10 g de cada isca por m² de sauveiro, em 5 repetições, constando cada parcela de 3 formigueiros, perfazendo um total de 60. O delineamento foi inteiramente ao acaso. Para a análise econômica dos resultados, foram utilizados os fatores: custo da isca, sua eficiência percentual e o valor da mão-de-obra requerida, para se determinar o custo médio de controle de um sauveiro extinto. Pelos valores calculados, como resultado, obteve-se o custo médio por sauveiro extinto na seguinte ordem: com a isca “EAV-04l-A” custou Cr$ 2,27; com a “Isca Shell” Cr$ 3,41; com “Agroceres” Cr$ 4,29 e com “Mirex” Cr$ 5,44, evidenciando a economia em favor da "EAV-041-A", tendo em vista o seu menor custo por quilograma (Na época em que os cálculos foram realizados, o valor cambial do Dólar era de Cr$ 6,00.

    An Experiment was conducted using a clorimated experimental bait called EAV-041-A. This experiment was conducted to determine the efficiency of EAV-041-A using the leaf-cutting ant Atta sexdens rubropilosa as the test. The experiment was executed in Goiânia, Goiás, comparing it with the commercial baits: Mirex, Isca Shell and Agroceres AG-005. Results obtained showed Mirex was superior giving 93.30% control of the nests, EAV-041-A 80.00% and Isca Shell and Agroceres both qave 73.30% control. Total cost of application was calculated based on price of the bait on the market hand labor in the region, and efficiency of the various baits. Cost calculated on the basis of ant nests killed were in the following order: EAV-041-A Cr$ 2.21; Isca Shell Cr$ 3.41; Agroceres Cr$ 4.29 and Mirex Cr$ 5.44 (At the time of these calculations the official exchange rate was Cr$ 6.00 to US$ 1.00. This evidence proved EAV-041-A to be the most economical.

  7. Biocontrol del moho foliar del tomate Cladosporium fulvum empleando cuatro hongos antagonistas Biocontrole do mofo foliar em tomateiro empregando quatro fungos antagonistas Biocontrol of leaf mold of tomato Cladosporium fulvum (Cooke 1883 employing four antagonistic fungi

    Directory of Open Access Journals (Sweden)

    Enrique Torres

    2008-01-01

    Full Text Available El moho foliar Cladosporium fulvum (Cooke 1883 produce una enfermedad que ataca el cultivo de tomate en invernadero en el Perú. Como alternativa al control de este patógeno se probó la eficiencia bajo condiciones in vitro e invernadero de cuatro hongos antagonistas: Hansfordia pulvinata (Berk y Curt 1958, Trichoderma harzianum (Rifai 1969, T. viride (Persoon 1821 y T. virens (Miller, Giddens y Foster 1963. El cultivo y crecimiento de los hongos se realizó en Agar Sabouraud para Trichoderma spp. y en Agar Jugo V8 para H. pulvinata. El bioensayo empleado fue el de placas precolonizadas propuesto por Krauss. En condiciones in vitro se observó que a 24 ºC y 72 h, el crecimiento de T. harzianum fue estadísticamente diferente de las otras tres especies ensayadas, y a 28 ºC fue similar a T. viride. A 24 ºC y a las 120 h, T. virens fue diferente de todas las especies evaluadas. A las 168 h el crecimiento de las tres especies de Trichoderma fue estadísticamente similar, diferenciándose de H. pulvinata. A 28 ºC a las 120 h y 168 h los resultados fueron estadísticamente similares para las tres especies de Trichoderma, pero diferentes de H. pulvinata. El mecanismo de acción más común para los hongos antagonistas fue el micoparasitismo. Finalmente, T. harzianum fue más eficiente debido a que redujo la severidad de la enfermedad en un 19,35 % bajo condiciones de invernadero.O mofo foliar Cladosporium fulvum (Cooke, 1883 produz uma enfermidade que ataca o cultivo do tomateiro em casa de vegetação no Peru. Como alternativa ao controle desse patógeno, testou-se a eficiência, sob condições in vitro e casa de vegetatção, de quatro fungos antagonistas: Hansfordia pulvinata (Berk y Curt 1958, Trichoderma harzianum (Rifai 1969, T. viride (Persoon 1821 y T. virens (Miller, Giddens y Foster 1963. O cultivo e crescimento dos fungos foi realizado em Agar Sabouraud para Trichoderma spp. e em Agar Suco V8 para H. pulvinata. O bioensaio empregado foi o de placas pré-colonizadas proposto por Krauss. Em condições in vitro, observou-se que a 24 °C e 72 horas, o crescimento de T. Harzinum foi estatisticamente diferente das outras três espécies estudadas, e a 28 °C foi semelhante a T. viride. A 24 °C e 120 horas, T. virens foi diferente de todas as espécies avaliadas. A 168 horas, o crescimento das três espécies de Trichoderma foi estatisticamente semelhante, diferenciando-se de H. pulvinata. A 28 °C e 120 e 168 horas, os resultados foram estatisticamente semelhantes para as três espécies de Trichoderma, mas diferentes de H. pulvinata. O mecanismo de ação mais comum para os fungos antagonistas foi o micoparasitismo. Finalmente, T. harzianum foi mais eficiente devido à redução da severidade da enfermidade em 19,35% sob condições de casa de vegetação.Leaf mold Cladosporium fulvum (Cooke 1883, produce a tomato crop disease under greenhouse in Peru. As an alternative to control this pathogen the efficiency under in vitro conditions and greenhouse conditions of four antagonistic fungi was probed: Hansfordia pulvinata Berk y Curt 1958, Trichoderma harzianum (Rifai 1969, T. viride (Persoon 1821 and T. virens (Miller, Giddens y Foster 1963. Fungal culture and growth was performed in Agar Sabouraud for Trichoderma spp. and in Agar Juice V8 for H. pulvinata. The bioassay employed was precolonized plates proposed by Krauss. In in vitro conditions was observed that at 24°C and 72 h growing of T. harzianum was statistically different than the other three species tested, and at 28°C was similar to T. viride. At 120 h and 24°C growing of T. virens was different from all species evaluated. At 168 h growing of the three species of Trichoderma, were statistically similar, varying from H. pulvinata. At 28°C and at 120 h and 168 h the results were statistically similar to the three species of Trichoderma, but different to H. pulvinata. Micoparasitism is the most common-action mechanism. Finally, T. harzianum was the most efficient antagonistic fungus because reduced disease in 19.35% under greenhouse conditions.

  8. Estudos eletroquímicos de uma célula termogalvânica de cobre empregando diferentes líquidos iônicos como eletrólito

    OpenAIRE

    Cíntia Caspers

    2012-01-01

    Células termogalvânicas são conversores termoelétricos que consistem de dois eletrodos imersos em uma solução eletrolítica mantidos em temperaturas diferentes. Esta diferença de temperatura gera uma diferença de potencial que pode ser empregada para conduzir corrente através de um circuito externo. Desta forma, energia térmica é convertida diretamente em energia elétrica. Os eletrodos normalmente utilizados em células termogalvânicas são inertes e apresentam custo elevado. Além disso, a soluç...

  9. Avaliação da labilidade de alumínio em infusões de erva-mate empregando voltametria adsortiva de redissolução catódica

    Directory of Open Access Journals (Sweden)

    Bruna Kauely de Campos

    2014-01-01

    Full Text Available Infusions of yerba mate obtained at different stages of industrialization were evaluated to determine the bioavailable fraction of Al. Adsorptive Cathodic Stripping Voltammetry using DASA (complexing agent was applied to determine the labile fraction of Al at pH 5.0 and pH 8.0 for the total fraction of dissolved Al. The results indicate that on average 60% of Al is complexed with organic compounds, minimizing their bioavailability; however, the labile fraction exceeds by up to 4 times the maximum weekly intake recommended by the World Health Organization.

  10. Determinação simultânea de topiramato, carbamazepina, fenitoína e fenobarbital em plasma empregando cromatografia a gás com detector de nitrogênio e fósforo

    OpenAIRE

    Roberta Zilles Hahn; Olyr Celestino Kreutz; Marina Venzon Antunes; Rafael Linden; Juliana da Silva; Cléber Álvares da Silva

    2013-01-01

    Topiramate and the other frequently co-administered antiepileptic drugs carbamazepine, phenytoin and phenobarbital were determined in 100 µL plasma samples by gas chromatography with nitrogen phosphorus detection (GC-NPD), after a one-step liquid-liquid extraction with ethyl acetate, followed by flash methylation with trimethylphenylammonium hydroxide. Total chromatographic run time was 12.5 min. Intra-assay and inter-assay precision was 2.5-7.3% and 1.6-5.2%, respectively. Accuracy was 100.1...

  11. Electrification of small rural properties in the Cangucu-Brazil city using alternative sources for electricity generation; Eletrificacao de pequenas propriedades rurais do municipio de Cangucu empregando fontes alternativas para a producao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Hecktheuer, Lucio Almeida [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Nucleo de Energia

    1998-12-31

    This paper aims at specifying and measuring the main alternative electrification system components, such as solar and eolic, which make use of the property`s energetical potential that, to a small extent, do not represent pollution sources to the environment. The results indicated that, the small rural properties of Cangucu country, which present a low daily electric energy consumption, these alternative systems are able to technically and economically supply electric energy and provide reasonable subsidies to electrification projects which can eventually be developed in the country. (author) 4 refs., 2 figs., 5 tabs.

  12. Estimative of dilution factor for radioactive liquid effluents employing the H-3 and Cs-137 radiotracers present as pollutant; Estimativa do fator de diluicao para efluentes radioativos liquidos empregando os radiotracadores H-3 e Cs-137 presentes como poluentes

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo Bessa; Santos, Adir Janete Godoy dos, E-mail: mbnisti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    It was estimated the dilution factor for liquid effluents at the discharge points of the IPEN, Sao Paulo, Brazil, employing as radiotracers the radioisotope routinely liberated for the sewage of 'Cidade Universitaria Armando de Salles Oliveira' - CUASO {sup 3}H and {sup 137}Cs, not generating either monetary or environmental cost associated to the estimation. The {sup 137}Cs was determined by gamma spectrometry and the {sup 3}H was determined liquid phase scintillation. The results showed that the dilution factor varied according to the employed radiotracer in a crescent order of {sup 3}H and {sup 137}Cs according to the characteristics of each element. The average of dilution factors obtained at the first and second liberation day were 4.3 and 7.4 respectively for the {sup 3}H and 6.2 and 13.9 for the {sup 137}Cs. The ratio of dilution factors of calculated {sup 3}H and {sup 137}Cs were coherent with the ratio verified at the twelve hydrometers distributed by the IPEN campus. The dilution factors were estimated in operational and laboratory study, in a single controlled discharge of the TR1 tank

  13. Epoxidation of castor oil and its derivatives using VO(acac){sub 2}/TBHP as the catalytic system; Epoxidacao do oleo de mamona e derivados empregando o sistema catalitico VO(acac){sub 2}/TBHP

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Marta Regina dos Santos [Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil). Dept. de Fisica e Quimica]. E-mail: mrsnunes@ucs.br; Martinelli, Marcia; Pedroso, Marcelo Monteiro [Universidade Federal do Rio Grande do Sul (UFRGS), Caxias do Sul, RS (Brazil). Dept. de Quimica Inorganica

    2008-07-01

    The alternative system VO(acac){sub 2}/TBHP was investigated for the epoxidation reaction of castor oil and its derivatives. Results of 88% of conversion, 73% of epoxidation and 82% of selectivity were obtained for the system containing 20% excess of TBHP and 1% of VO(acac){sub 2} catalyst, during 3 h under toluene reflux. The product was characterized by GC/MS as methyl-cis-9, 10-epoxi, 12- hydroxystearate and quantitative {sup 1}H NMR was used to calculate the data above. Preliminary results indicate that the heterogeneous system VO(acac){sub 2} grafted on K10 clay can also promote epoxidation of castor oil. (author)

  14. Evaluation of thermoluminescent dosimeters using water equivalent phantoms for application in clinical electrons beams dosimetry; Avaliacao de dosimetros termoluminescentes empregando objetos simuladores equivalentes a agua para aplicacao na dosimetria de feixes clinicos de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, Amanda

    2010-07-01

    The dosimetry in Radiotherapy provides the calibration of the radiation beam as well as the quality control of the dose in the clinical routine. Its main objective is to determine with greater accuracy the dose absorbed by the tumor. This study aimed to evaluate the behavior of three thermoluminescent dosimeters for the clinical electron beam dosimetry. The performance of the calcium sulfate detector doped with dysprosium (CaSO{sub 4}: Dy) produced by IPEN was compared with two dosimeters commercially available by Harshaw. Both are named TLD-100, however they differ in their dimensions. The dosimeters were evaluated using water, solid water (RMI-457) and PMMA phantoms in different exposure fields for 4, 6, 9, 12 and 16 MeV electron beam energies. It was also performed measurements in photon beams of 6 and 15 MV (2 and 5 MeV) only for comparison. The dose-response curves were obtained for the {sup 60}Co gamma radiation in air and under conditions of electronic equilibrium, both for clinical beam of photons and electrons in maximum dose depths. The sensitivity, reproducibility, intrinsic efficiency and energy dependence response of dosimeters were studied. The CaSO{sub 4}: Dy showed the same behavior of TLD-100, demonstrating only an advantage in the sensitivity to the beams and radiation doses studied. Thus, the dosimeter produced by IPEN can be considered a new alternative for dosimetry in Radiotherapy departments. (author)

  15. Determinação Voltamétrica do Antioxidante Galato de Propila em Biodiesel Empregando Eletrodos de Pasta de Carbono Modificados com Líquido Iônico

    Directory of Open Access Journals (Sweden)

    Luiz Henrique de Oliveira

    2015-01-01

    Full Text Available In this work a carbon paste electrode chemically modified with an ionic liquid (CPE-IL was used to quantify the antioxidant propyl gallate (PG in spiked soybean biodiesel samples by square wave voltammetry. Under the optimized conditions, the proposed method have presented a linear range from 2.0 to 47.5 μmol L-1, with limit of detection equal to 0.397 μmol L-1. Recovery studies were performed in biodiesel samples spiked with two levels of PG. In all cases, satisfactory recovery percentages and low relative standard deviation values were obtained which is a clear demonstration of the accuracy of the proposed method. It was observed that IL provides a remarkable intensification of PG voltammetric response compared to a non-modified conventional CPE, improving, therefore, the detectability of the voltammetric method. The CPE-IL used in this work does not require an IL completely free from residual water. This is a very attractive feature because time-consuming procedures for water elimination are avoided during the synthesis of the IL. Thus, the proposed CPE-IL can be prepared in a simple, fast and inexpensive way making these electrodes very practical and competitive compared to other chemically modified electrodes proposed in the literature for PG quantification.

  16. Primary and scattering contributions to beta scaled dose point kernels by means of Monte Carlo simulations; Contribuicoes primaria e espalhada para dosimetria beta calculadas pelo dose point kernels empregando simulacoes pelo Metodo Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Mauro [CONICET - Consejo Nacional de Investigaciones Cientificas y Tecnicas de La Republica Argentina (Conicet), Buenos Aires, AR (Brazil); Botta, Francesca; Pedroli, Guido [European Institute of Oncology, Milan (Italy). Medical Physics Department; Perez, Pedro, E-mail: valente@famaf.unc.edu.ar [Universidad Nacional de Cordoba, Cordoba (Argentina). Fac. de Matematica, Astronomia y Fisica (FaMAF)

    2012-07-01

    Beta-emitters have proved to be appropriate for radioimmunotherapy. The dosimetric characterization of each radionuclide has to be carefully investigated. One usual and practical dosimetric approach is the calculation of dose distribution from a unit point source emitting particles according to any radionuclide of interest, which is known as dose point kernel. Absorbed dose distributions are due to primary and radiation scattering contributions. This work presented a method capable of performing dose distributions for nuclear medicine dosimetry by means of Monte Carlo methods. Dedicated subroutines have been developed in order to separately compute primary and scattering contributions to the total absorbed dose, performing particle transport up to 1 keV or least. Preliminarily, the suitability of the calculation method has been satisfactory, being tested for monoenergetic sources, and it was further applied to the characterization of different beta-minus radionuclides of nuclear medicine interests for radioimmunotherapy. (author)

  17. Aumento da resposta analítica por meio da otimização do sistema de injeção sem divisão de fluxo em cromatografia gasosa empregando a lei dos gases ideais

    Directory of Open Access Journals (Sweden)

    Guilherme Post Sabin

    2011-01-01

    Full Text Available This paper reports the development of an easy, fast and effective procedure for the verification of the ideal gas law in splitless injection systems in order to improve the response. Results of a group of pesticides were used to demonstrate the suitability of the approach. The procedure helps establish experimental parameters through theoretical aspects. The improved instrumental response allowed extraction with lower sample volumes, the minimization of time and costs and the simplification of sample preparation.

  18. Determinação condutométrica de cloridrato de metformina em formulações farmacêuticas empregando nitrato de prata como titulante Conductometric determination of metformin hydrochloride in pharmaceutical formulations using silver nitrate as titrant

    Directory of Open Access Journals (Sweden)

    Elen Romão Sartori

    2009-01-01

    Full Text Available A simple, precise, rapid and low-cost conductometric titration method for the determination of metformin hydrochloride (MET in pharmaceuticals using silver nitrate as titrant is proposed. The method was based on the chemical reaction between the chloride of metformin hydrochloride molecule and Ag(I ions, yielding the precipitate AgCl(s. The method was applied for MET determination in three pharmaceuticals and the obtained results with proposed method were in close agreement with those results obtained using an official method of the British Pharmacopoeia, at a 95% confidence level.

  19. {sup 137}Cs radioactive check device for quality and stability control of dosimeters used in radiotherapy; Controle de qualidade e estabilidade de dosimetros usados em radioterapia empregando fontes de {sup 137}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Alves, C.F.E.; Mondaini, C.V.; Leite, S.P.; Pires, E.J.; Magalhaes, L.A.G.; Daivd, M.G.; Almeida, C.E. de, E-mail: cfealves@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Lab. de Ciencias Radiologicas; Di Prinzio, R. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This paper describes the design and construction of a shielded container to store a used brachytherapy {sup 137}Cs source. This system proposes a new option to check the periodical consistency and proper functioning of ionization chambers and electrometers used in radiotherapy. Since there is no similar equipment being produced in the Brazilian market and the chambers stability control is part of a licensing requirement this device was built to meet the needs of several radiotherapy centers without access to it. (author)

  20. Effect of amount of glycine as fuel in obtaining nanocomposite Ni/NiO; Efeito da quantidade de glicina como combustivel na obtencao de nanocompositos Ni/NiO

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, A.N.; Simoes, V.N.; Neiva, L.S.; Quirino, M.R.; Vieira, D.A.; Gama, L., E-mail: alluskynha@hotmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2010-07-01

    This paper proposes to investigate the effect of the amount of glycine in obtaining nanocomposite Ni/NiO synthesized by combustion reaction technique. The amount of glycine used was calculated on the stoichiometric composition of 50% and 100%. Characterizations by X-ray diffraction (XRD), N2 adsorption by the BET method and scanning electron microscopy (SEM) were performed with powder of Ni/NiO result. The analysis of X-ray diffraction showed the presence of crystalline NiO phase in the presence of nickel as a secondary phase, whose amount increased with the amount of glycine. Increasing the concentration of glycine also caused an increase in surface area, which ranged from 1.1 to 1.4 m{sup 2}/g. The micrographs revealed the formation of soft agglomerates with porous appearance and easy dispersions. It can be concluded that the synthesis is effective to obtain nanosized powders. (author)

  1. Performance of direct ethanol fuel cells as function of using of compressed air; Desempenho de celulas a combustivel com alimentacao direta de etanol em funcao do uso de ar comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Belchor, P.M. [UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Berns, B.A.; Ferreira, R.C.; Goldbach, A.; Carpenter, D. [FURB - Fundacao Universidade Regional de Blumenau, Blumenau, SC (Brazil)

    2010-07-01

    This paper compared the performance of a direct ethanol fuel cell (CCADE) cathode feeding with air replacing the pure oxygen. The results have shown that the small decreasing of the yield of the cell under both practical and experimental situations, by the use of air replacing pure oxygen, it completely acceptable as function of great diminishing of operational costs. (author)

  2. On the applicability of a correlation of critical heat flux prediction for advanced nuclear fuel from Angra-1; Confirmando a aplicabilidade de uma correlacao de previsao do fluxo de calor critico para o combustivel nuclear avancado de Angra-1

    Energy Technology Data Exchange (ETDEWEB)

    Palheiros, Franklin L.; Gomes, Sydney [Industrias Nucleares do Brasil SA, Rio de Janeiro, RJ (Brazil). Gerencia de Analise Tecnica do Combustivel]. E-mail: franklin@inb.gov.br; sydney@inb.gov.br

    2005-07-01

    To establish the nuclear core operation limits it is requested that the safe condition of heat transfer between the fuel rod and the primary system coolant shall be well known. Those limits are set based on the critical heat flux marking the upper limit of nucleate boiling where the interaction of the coolant causes a departure from nucleate boiling - DNB [1]. For the new fuel type (16NGF) to be used at the Angra-1, the Kori-2, and the Krsko sites, the Critical Heat Flux must be characterized as well. Compared to the 16x16STD fuel (a 25+ year old Westinghouse design), the 16NGF design has many new features, including: three Intermediate Flow Mixers (IFM's) were added in the grid spans 4, 5 and 6 to improve the mixing behavior and consequently the thermal margin; an optimized vane pattern was used as well as an improved vane design (RFA Mod-1 vane). Others important thermal characteristics are the use of an optimized fuel rod diameter- from the U/H ratio point of view (0.360'' instead of 0.374'') and others features (Reference 2).Therefore, to demonstrate the applicability of an existing CHF correlation for the 16NGF design, two tests were performed in the Columbia University's Heat Transfer Research Facility, New York City (HTRF). Denominated Tests number 112 and number 113, they employed a 5x5 bundle array with a heated length of 12 ft. and cosine axial power shape. The purpose of this paper is then to present the data analysis from the 16NGF CHF tests and demonstrate, through a statistical evaluation, that the resulting data when evaluated is 'poolable' (combinable) with the WRB-2 database. In so doing, it can be thus stated that the WRB-2 correlation is applicable to 16 NGF Fuel Assemblies. (author)

  3. Synthesis of yttria-doped zirconia anodes and calcium-doped ceria electrolyte to fuel cell; Sintese de anodos de zirconia dopada com itria e eletrolito de ceria dopada com calcia para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, G.R.S de; Fagury Neto, E.; Rabelo, A.A., E-mail: grs_gustavo@hotmail.co [Universidade Federal do Para (UFPA), Maraba, PA (Brazil). Fac. de Engenharia de Materiais

    2010-07-01

    From the pursuit of lower operating temperature of fuel cells solid oxide was used polymeric precursor for the synthesis of reactive powder compositions Zr{sub 0,92}Y{sub 0,08}O{sub 2} for the anode and Ce{sub 0,88}Ca{sub 0,12}O{sub 2} for the electrolyte. The solutions were prepared using the metal in much of the composition and citric acid molar ratio of 1:3, under stirring at 60 deg C/1 h. The mixture of metallic citrates was subjected to agitation at a temperature of 80 deg C which was added ethylene glycol in the ratio 60:40 by weight citric acid / ethylene glycol, to form a resin that was pre-calcined at 300 deg C/3 h for to form the expanded resin. The powders were disaggregated in a mortar, screened and calcined at 400, 600 and 800 deg C/2 h. The powders were characterized by standard X-ray diffraction. (author)

  4. Microstructural development and characterization of lanthanum chromite-based ceramics to application in solid oxide fuel cells; Desenvolvimento microestrutural e caracterizacao de ceramicas a base de cromita de lantanio para aplicacao em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R.N.; Furtado, J.G. de M.; Soares, C.M.; Serra, E.T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)], e-mail: rnunes@cepel.br

    2006-07-01

    This work has for objective to investigate and to characterize the microstructural development of lanthanum chromite-based ceramics (LaCrO{sub 3}) doped with earth alkaline metals, correlating the microstructural parameters (mainly the densification level) and processing parameters with the electrothermal properties reached. Lanthanum chromite-based ceramic systems doped with earth-alkaline metals (Ca, Mg and Sr) had been produced from respective metallic nitrates by solid state reactions process. The phase compositions were evaluated by X-ray diffraction and the densification level by Archimedes method. The microstructural characterization was effected by scanning electron microscopy, energy dispersive X-ray spectroscopy and thermal analysis techniques. Electrical tests were used to evaluate the electrical conductivity of the studied ceramics. The obtained results corroborate the literature comments concerning the difficulty of lanthanum chromite-based ceramics with high densification level and evidence the great influence of the nature of the dopants on the sintering mechanism and the microstructural and electric characteristics of the produced ceramics. The best ones results, in terms of densification and electrical conductivity, had been gotten through multiple doping with calcium and strontium, and in sintering temperature conditions lower that the normally considered to pure or monodoped lanthanum chromite-based ceramics. (author)

  5. Co-sintering of CGO/NIO-CGO bilayers for solid oxide fuel cell; Co-sinterizacao de bi-camadas anodo/eletrolito para celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Neto, P.P.B.; Grilo, J.P.F.; Souza, G.L.; Macedo, D.A.; Paskocimas, C.A.; Nascimento, R.M., E-mail: pbritoneto@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    Reducing the operating temperature of solid oxide fuel cells (SOFC) for the range between 500 and 700°C is one of the challenges which more has aroused the interest of research in SOFC in recent years. In this context, the bilayer anode/electrolyte composed of a porous support based on Ni-doped ceria (anode) and a ceria doped gadolinia (CGO) electrolyte, presents itself as one of the half-cell configurations of the most interest towards the production of electricity in the operating logic of a SOFC. In this work, CGO films were successfully prepared on NiO-CGO substrates using the resources of the screen-printing technique. The bi-layers were co-sintered between 1350 and 1450 ° C for 4 h and then characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS). The results showed good adhesion at the film/substrate interface and no cracks in the films. (author)

  6. Preparation of cathode materials for solid oxide solid fuel (SOFC) using gelatin; Preparacao de materiais catodicos para celulas a combustivel de oxido solido (SOFC) atraves do uso de gelatina

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.M.; Aquino, F. de M.; Macedo, D.A. de; Sa, A.M.; Galvao, G.O., E-mail: rinaldo_mendesa@hotmail.com [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

    2016-07-01

    Fuel cells are electrochemical devices that convert chemical energy into electrical energy. These devices are basically divided into interconnectors, electrolyte, anode, and cathode. Recently, studies of improvements in microstructural and morphological properties of calcium cobaltate (Ca{sub 3}Co{sub 4}O{sub 9}, C349) has been made regarding its potential use as SOFC cathode for intermediate temperature. Gelatin has proven to be effective as a polymerizing agent in the synthesis of nanocrystalline materials. This work reports the synthesis and characterization of the C349 cathode using commercial gelatin. The structural properties of the material were determined by X-ray diffraction (XRD). Morphological characterization was performed by scanning electron microscopy (SEM). The results showed the formation of the crystalline phase at 900 °C, indicating the effectiveness of the gelatin in the preparation of cathodes for SOFC. (author)

  7. Modified hydrogenated PBLH copolymer synthesis with styrene for proton exchange membranes fuel cell application; Derivados de PBLH hidrogenado na sintese de copolimeros com estireno, para a producao de membranas cationicas para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz, Fernando A.; Oliveira, Angelo R.S.; Rodrigues, Maraiza F.; Groetzner, Mariana B.; Cesar-Oliveira, Maria Aparecida F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos (LABPOL)]. E-mails: ferraz@quimica.ufpr.br; angelorsoliveira@ig.com.br; maraiza@quimica.ufpr.br; marianabitt@brasilh2.com.br; mafco@quimica.ufpr.br; Cantao, Mauricio P. [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)]. E-mail: cantao@lactec.org.br

    2005-07-01

    Polymers used as electrolyte in fuel cells are expected to have functional groups in their structure which are responsible for proton conductivity. Since the use of hydroxylated liquid polybutadiene (PBLH) has not been mentioned in the literature as an ion exchange membrane for fuel cell application (PEMFC), and its structure can be modified for a later sulfonation, it has been studied. In this work, PBLH was modified through a hydrogenation reaction. Furthermore, hydrogenated polymeric esters were obtained by esterification and transesterification reactions (PBLH- estearate and PBLH- methacrylate). Reacting the PBLH methacrylate with styrene, it was generated a copolymer with appropriated structure for sulfonation, justifying researches for fuel cell. (author)

  8. Technical evaluation of biomass gasification technology integrated with combined cycle using bagasse as fuel; Avaliacao tecnica da tecnologia de gaseificacao de biomassa integrada a ciclos combinados utilizando bagaco como combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Silva; Venturini, Osvaldo Jose; Lora, Electo Silva [Universidade Federal de Itajuba (NEST/UNIFEI), MG (Brazil). Nucleo de Excelencia em Geracao Termeletrica e Distribuida], email: pablo.silvaortiz@gmail.com; Campo, Andres Perez [Universidade Automona de Bucaramanga (UNAB) (Colombia). Fac. de Engenharia Fisico- Mecanica, Engenharia em Energia

    2010-07-01

    Biomass Integrated Gasification Combined Cycle (BIGCC) was identified as an advanced technology with potential to be competitive for electricity generation. The BIGCC technology uses biomass and the sub products of some industrial sectors processing, like sugar cane, as feedstock. The current Brazilian energy matrix is mainly based on renewable generation sources, making it important to assess these gasification technologies in the production of sugar, ethanol and electricity. In this work, a technical evaluation of the technologies incorporated in BIGCC power plants is done: the gasification process and the combined cycle power plant. On the other hand, the generated costs of these systems are analyzed, and the potential for implementation in Brazil plants from sugar cane bagasse is studied, in which a 10% increase in efficiency is obtained. (author)

  9. Fuel consumption of tractor for different soil types in semi-arid regions; Consumo de combustivel de um trator agricola para diferentes tipos de solo em regioes semi-aridas

    Energy Technology Data Exchange (ETDEWEB)

    Montanha, Gustavo K. [Universidade Estadual Paulista (FAC/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], E-mail: gmontanha@fca.unesp.br; Guerra, Saulo P.S. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Dept. de Gestao e Tecnologia Agroindustrial; Andrade-Sanchez, Pedro; Heun, John [The University of Arizona, Maricopa, AZ (United States); Monteiro, Leonardo A. [The University of Arizona (MAC/UA), Maricopa, AZ (United States). Maricopa Agricultural Center

    2010-07-01

    The appropriate use of agricultural machinery enables greater operational efficiency and higher productivity for the farmer. Some factors such as soil type can influence the fuel consumption, one of the biggest costs. This study aimed to compare the fuel consumption of a tractor operating in two different conditions of soil in semi-arid regions. The area used for testing is located in the city of Maricopa, in Arizona, belonging to 'The University of Arizona'. The area 1 is classified as sandy clay loam soil (52% sand, 35% clay, 13% silt). The area 2 is classified as a sandy loam soil (71% sand, 12% clay and 17% silt). The tractor 4 x 2 TDA, with 88 kw (120 hp) engine power equipped with auto pilot system and an implement for tillage were used in the experiment. A data acquisition system was installed in the tractor to collect the data generated by the GPS and fuel consumption sensor. The results showed significant statistical difference in fuel consumption between soil textures. (author)

  10. Removal of ammonia generated from farm poultry and their use in the fuel cells and as fertilizer; Remocao de amonia gerada em granjas avicolas e sua utilizacao em celulas a combustivel e uso como fertilizante

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Joao Coutinho

    2010-07-01

    The process here stressed uses a cation exchange material. The aim of the present work has been to prepare a suitable cation exchanger material with especially high selectivity for ammonia, as the cation NH{sub 4+} or as aqueous ammonia solution containing NH{sub 4}OH hydroxide as well. Aliquots of the above mentioned exchangers were set up inside an chicken farm production near Sao Paulo city. Periodically the exchanger was removed to the laboratory and eluted with a convenient acid to regenerate the exchanger for the new cycle. The ammonia retention was quite high and presents no difficulty for its elution. The selected exchanger is a solid material, non toxic, without smell and have good physical properties. The first results encouraged us and our plants to do large experiments that in progress. This process is a contribution to remediation of the avicola local, removing the ammonia gas and suppressing greatly its smell and bad effect to the animals and even to workers. (author)

  11. Synthesis and characterization of sulfonic acid membranes based on interpenetrating polymer networks for application in fuel cells; Sintese e caracterizacao de membranas sulfonadas baseadas em redes polimericas interpenetrantes para aplicacao em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Lyzed Toloza; Loureiro, Felipe A.M.; Rocco, Ana Maria [Grupo de Materiais Condutores e Energia, Escola de Quimica, Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)], e-mail: amrocco@eq.ufrj.br; Pereira, Robson Pacheco [Instituto de Ciencias Exatas, Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil)

    2011-07-01

    In the present work, the synthesis and characterization of sulfonic membranes based on interpenetrating polymer networks (IPN). In order to obtain such systems, the diglycidyl ether of bisphenol A (DGEBA) was polymerized in presence of polyethyleneimine (PEI). These membranes were submitted to sulfonation reactions, originating IPN-SO{sub 3}H membranes. The characterization by FTIR evidenced the formation of a Semi-IPN structure, while sulfonation reactions resulted in systems containing -SO{sub 3}H groups covalently bonded to the chains. The membranes exhibited water retention up to 200 degree C, in a temperature range sufficient for application in PEMFC under hydration. (author)

  12. Electric energy supply to isolated residences from the network through low power fuel cells; Fronecimento de energia eletrica a residencias isoladas da rede atraves de celulas a combustivel de baixa potencia

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Eduardo Torres; Furtado, Jose Geraldo de Melo [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)], e-mail: etserra@cepel.br, e-mail: furtado@cepel.br

    2008-07-01

    This paper discusses the technical and socio economical aspects of the utilization of fuel cells for supplying electric power to isolated residences under an analysis on the global and brazilian energy scenarios, focusing the ascertaining of the high inequality of electric energy consumption among the various regions and countries in the world and the electric power access viability for the population lesser favoured. The paper performs an energetic analysis allowing an estimate of daily average consumption of electric energy of a low income family, and also discusses an attendance alternative of this demand by using small generation unities consisting of polymeric membranes fuel cells and reformers of primary fuel. Also, the paper analyses the possibilities of using various fuels for the hydrogen production to be used in fuel cell and estimates the cost of electric energy generated as function the main parameters which characterizes the enterprise.

  13. Development of electrode-membrane-electrode assemblies for proton exchange membrane fuel cells (PEMFC) by Sieve printing; Desenvolvimento de conjuntos eletrodo-membrana-eletrodo para celulas a combustivel a membrana trocadora de protons (PEMFC) por impressao a tela

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Alexandre Bodart de

    2008-07-01

    The Sieve Printing process was studied in this work to apply the catalyst layers onto electrolytes utilized in PEMFC. Initially, 25 cm{sup 2} active area MEAs were built for comparison with others MEAs produced by the Spray technique. The two methods produced MEAs that showed current densities higher than 600 mA.cm{sup -2} at 600 mV. A scaling up study for 144 cm{sup 2} of active area MEAs was carried out. For this purpose, a new cell had to be projected for shelter the MEAs in such dimensions. The profile of the gas distribution channels was developed through the computational fluid dynamic tool 'Comsol Multiphysics'. For the design of the bipolar plates of the cell the 'Auto CAD' was used. The 144 cm{sup 2} MEAs made by Spray and by Sieve Printing methods were confronted with commercials MEAs ones of equal dimensions. These commercials MEAs presented better performance at 600 mV, however they were more costly than the solution developed in this study. The new method was showed to be adequate to fabricate low cost MEAs of different geometries and to produce any amount of MEAs for small scale stacks (up to 10 kW). (author)

  14. Experimental energetic analysis of gas natural-powered fuel cell cogeneration plant; Analise energetica experimental de uma planta de co-geracao com celulas a combustivel e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose G.M.; Lopes, Francisco C.; Silva Junior, Fernando R.; Soares, Guilherme F.W.; Serra, Eduardo T. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economy of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  15. Validation of the small scale alcohol fuel production process: social-economic and environmental aspects; Validacao do processo de producao de alcool combustivel em pequena escala: aspectos socio-economicos e ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Flavio Dias; Serafini, Seimur; Colusso, Gabriel; Hoffmann, Rejane; Jahn, Sergio Luis; Hoffmann, Ronaldo [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Centro de Tecnologia], e-mail: flaviodmayer@yahoo.com.br

    2008-07-01

    This paper investigates the possibility of fuel alcohol production at the Northwestern of the state of Rio Grande do Sul, Brazil, which have their subsistence structure based on the typical cultures of the region, and where is implanted the sugar cane culture on characteristic incline soil, called marginal. The raw material exploration system is performed in micro-distillery scale and that demonstrate great importance for the regional development. For that scale, the technologies are simplified, which compromises the incomes, presenting however social and economical improvements for the region.

  16. Development of a computational model applied to a unitary 144 CM{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm{sup 2} of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  17. Analysis and development of an ethanol compact reformer for hydrogen production for fuel cell; Analise e modelagem de reformador compacto de etanol para obtencao de hidrodenio para celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, P.R.F.; Oliveira, A.A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], e-mail: renzo@labcet.ufsc.br, e-mail: amirol@emc.ufsc.br

    2006-07-01

    The objective of this work is to analyze the ethanol steam reforming for hydrogen production in a compact and modular reforming unit designed for the generation of 1 kw of electrical power. For this, initially the thermodynamic limits for the steam reforming of ethanol are calculated in order to assess the limits in the production of hydrogen and other by-products and to select the best values of process stoichiometry, temperature and pressure for maximum hydrogen selectivity and minimum coke formation. In the following, a First and second Laws analysis is performed to analyze the equilibrium conditions of the main chemical reactions and to estimate the magnitude of the heat transfer required by the heating, evaporation, superheating and reforming of ethanol. Then, the catalytic reformer reactor is analyzed and sized, basing the analysis into the application of the equation for the conservation of mass of the chemical species and a model for the chemical kinetics. A basic reactor design is then proposed accompanied by the corresponding sizes and operating conditions. (author)

  18. Uncertainty of efficiency of a fuel cell with the establishing of suitable instrumentation for his measurement; Incerteza da eficiencia de uma celula a combustivel com o estabelecimento da instrumentacao adequada para a sua medicao

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Sergio Pinheiro de; Trota Filho, Jorge; Couto, Paulo Roberto Guimaraes; Rocha, Adriana da Cunha [Instituto Nacional de Metrologia Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias, RJ (Brazil)]. E-mail: spoliveira@inmetro.gov.br

    2008-07-01

    This work presents and compares the results obtained from the assessment of the uncertainty of measurement of the energetic efficiency calculations of a PEM unit fuel cell and from the total electrical power of a PEM fuel cell stack. This assessment makes use of three different methods of calculation: the Classical method and the Kragten method, both described in the ISO GUM 95 'Guide to the expression of uncertainty in measurement' and the Monte Carlo method, described in the Supplement 1 to the ISO GUM 95. Concerning the energetic efficiency, both the Classical and Kragten methods presented the same uncertainty values, 0.00029 whereas the Monte Carlo method presented a value of 0.00021. The difference between these two values (0.8 x 10{sup -5}) was greater than the {delta} criteria tolerance established in the Supplement 1 (0.5 x 10{sup -5}). This fact though, has not invalidated the results of the ISO GUM 95, as this work focused on the conservative value of the uncertainty. With respect to the uncertainty of the total electrical power of the fuel cell stack it has been observed that the main contribution for the uncertainty calculation, i.e., the higher uncertainty source (92.8%), was given by the accuracy class of the multimeter employed in the measurements. Additionally to the comparative study of the methods for the uncertainty calculations, this work establishes the correct accuracy class of a multimeter used for the measurement of the given/consumed electric potential by a fuel cell stack, aiming the cost/benefit relation of the process. (author)

  19. Processing of strontium-doped lanthanum manganite suspensions for cathode production of the solid oxide fuel cell; Processamento das suspensoes de manganito de lantanio dopado com estroncio para fabricacao do catodo da celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, R.; Vargas, R.A.; Andreoli, M.; Seo, E.S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais. Lab. de SOFC - Insumos e Componentes

    2008-07-01

    The ceramic material, strontium-doped lanthanum manganite (La{sub 0,85}Sr{sub 0,15}MnO{sub 3} - LSM), has been used as cathode in Solid Oxide Fuel Cells (SOFCs). The cathode attainment as component of the SOFCs has been studied for diverse routes of synthesis and thin films forming in Yttria-stabilized zirconia (ZrO{sub 2}/Y{sub 2}O{sub 3} - YSZ) electrolyte. In this work, the LSM was synthesized by the citrate technique and deposited in YSZ substrate using the forming technique wet powder spraying. Rheological studies of suspensions and chemical, physical and microstructural characterizations of LSM powders were made, aiming at the deposition for thin films formation until 50 mum. The half unit cells LSM/YSZ sintered were characterized by scanning electron microscopy, for verification of porosity and adherence. In this sense, this work is a contribution for production of porous cathode using the forming technique wet powder spraying in the SOFCs. (author)

  20. Evaluation of alternatives for reducing the consumption of natural gas fuel at city-gates of Brazilian transport systems; Avaliacao das alternativas de reducao do consumo de gas natural combustivel nos pontos de entrega dos sistemas de transporte brasileiros

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Almir B. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil); Augusto, Cristiane R.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Goncalves, Raquel G. [UNISUAM - Centro Universitario Augusto Motta, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work aims to identify actions that can be implemented to increase the energy efficiency of processes involved in the value chain of natural gas, specifically in the process of heating in existing city-gates of transporting natural gas Brazilians plants. The goal is increase supply of gas in Brazil. The main function of city-gates is to deliver the natural gas in contract terms (flow, pressure, temperature and quality). The main issue related to the consumption of natural gas fuel in city-gates is related to the operation (set-up and control) of natural gas combustion, in other words, depends on how the heating system is adjusted dynamically to burn, efficiently, the exact amount of gas required by this system, depending on temperature, pressure, temperature, quality and flow of natural gas at the 'city-gates'. The main objective of this work is to present a study on alternatives at design, set-up and control of natural gas city-gates (transport) in Brazil, aiming to increase the energy efficiency of this facility, and thus contributing to the growth in supply of natural gas available to the market. (author)

  1. Production of membrane-electrode assemblies to be used in high temperature solid oxide fuel cells; Producao de conjugados eletrolito-eletrodos para pilhas a combustivel de oxido solido de alta temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Villalobos, Pedro R.; Silva, Gilmar Clemente; Miranda, Paulo Emilio V. de [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Metalurgica e de Materiais. Lab. de Hidrogenio], e-mail: vlobos@labh2.coppe.ufrj.br

    2004-07-01

    This article describes the production and characterization of membrane-electrode assemblies to be used in high temperature solid oxide fuel cells. The single cells produced were characterized using scanning electron microscopy and X ray diffractometry, seeking the morphological characterization of the complete device and to verify the stability of the materials used with respect to the processing conditions. (author)

  2. Ethanol pilot project: an energy alternative project for a total or partial substitution of fuel oil in thermoelectric generation plants; Projeto piloto do etanol - PPE: alternativa energetica para substituicao parcial ou total do oleo combustivel em plantas de geracao termoeletrica

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Joao Simoes

    2004-07-01

    The actual stage of technological development is strongly dependent on wide use of petroleum combustibles, in which its trade market defines the rules of socio economical and geopolitics interdependencies. The economic growth has been driven by the 'readily available - cheap energy' stimulus, limiting studies on natural sources of energy (geothermal, solar) and development of renewable ones (bio combustibles). However, economical, financial crisis may change this scenario, and new opportunities for a change in the technological matrix and in technological structure might occur. In Brazil, the 'Agenda 21', especially the PPA - Applied Research Program in the Energetic Area, intend to develop case studies and implement 'pilots projects' to research conventional and renewable sources of energy, bringing to present the value of this project, developed between 1979 and 1980, to evaluate the technical feasibility of ethylic alcohol utilization as a complementary combustible or in a total substitute for the fuel oil in boilers of conventional thermoelectric generation plants. This work presents the performance of one of the Piratininga thermal power plant's boiler, as well as the main data acquired from direct experimentation and the characteristics of this plant, from the use of ethylic alcohol as a substitute of fuel oil. (author)

  3. Synthesis and ceramic processing of zirconia alumina composites for application as solid oxide fuel cell electrolytes; Sintese e processamento de compositos de zirconia-alumina para aplicacao como eletrolito em celulas a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rafael Henrique Lazzari

    2007-07-01

    The global warmness and the necessity to obtain clean energy from alternative methods than petroleum raises the importance of developing cleaner and more efficient systems of energy generation, among then, the solid oxide fuel cell (SOFC). Cubic stabilized zirconia (CSZ) has been the most studied material as electrolyte in SOFC, due to its ionic conductivity and great stability at operation conditions. However, its low fracture toughness difficulties its application as a thin layer, what could lead to an improvement of cell efficiency. In this sense, the alumina addition in CSZ forms a composite, which can shift its mechanical properties, without compromising its electrical properties. In this work, coprecipitation synthesis route and ceramic processing of zirconia-alumina composites were studied, in order to establish optimum conditions to attain high density, homogeneous microstructure, and better mechanical properties than CSZ, without compromising ionic conductivity. For this purpose, composites containing up to 40 wt % of alumina, in a 9 mol % yttria-stabilized zirconia (9Y-CSZ) matrix were evaluated. In order to optimize the synthesis of the composites, a preliminary study of powder obtaining and processing were carried out, at compositions containing 20 wt % of alumina, in 9Y-CSZ. The ceramic powders were characterized by helium picnometry, X-ray diffraction, scanning electronic microscopy, transmission electronic microscopy, thermogravimetry, differential scanning calorimetry, granulometry by laser diffraction and gas adsorption (BET). The characterization of sinterized compacts were performed by X-ray diffraction, scanning electron microscopy, optical microscopy, density measurements, Vickers indentation and impedance spectroscopy. The obtained results show that the alumina addition, in the 9Y-CSZ matrix powders, raises the specific surface area, promotes deagglomeration of powders and elevates the oxides crystallization temperature, requiring higher energetic thermal treatments to attain high densities. In relation to the sintered products, it was confirmed the excellent homogeneity and crystallinity of microstructure provided by the chosen route, the restriction of grain growth by alumina addition, raise of hardness and fracture toughness, and higher ionic conductivity, even tough a lower bulk conductivity. These results indicate that the addition of 5 wt % alumina in CSZ matrix allows the application of this material as solid oxide fuel cell electrolytes, due to its better fracture toughness and ionic conductivity, compared to yttria-stabilized cubic zirconia ceramics. (author)

  4. Optimal design of a hybrid photovoltaic and fuel cell power generation system, to supply isolated communities in the Brazilian Amazon; Dimensionamento otimo de sistemas hibridos, com geracao fotovoltaica e celula a combustivel, para atendimento a comunidades isoladas na Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sergio Batista da

    2010-11-15

    The lack of electricity in isolated communities in the Brazilian Amazon has become one of the greatest barrier for the development of the region. Currently, the main technologies that provide electricity to these communities are diesel generators, batteries and dry cells. These non-renewable energy sources may pose serious problems to the environment and human health and have high maintenance and operational costs. Therefore, the search for renewable energy sources, such as water and sunlight, which are highly abundant in the region, has become a great challenge. This thesis presents the studies on application of solar photovoltaic (PV) and fuel cell (FC) technologies to supply electric power in an uninterrupted manner. Outlined are the technical and cost issues of a pilot project set up in an environmentally protected area, next to Bananal island, located in the Southwestern region of the state of Tocantins. The pilot project relies on PV solar power as the primary source of energy for the production of electricity. The surplus energy is stored in the form of hydrogen produced by electrolysis of the water supplied locally, which is reconverted into electric power by fuel cells during periods when there is little or no sunlight. In this context, the aim of the study was to propose a sizing of a hybrid distributed generation system (HDGS), comprised of a PV system, FC and batteries, that optimizes implementation and operational costs, as a potential source of energy for isolated communities in the Amazon. The work was carried out with the help of simulation software HOMER (Hybrid Optimization Model for Electric Renewable) developed by National Renewable Energy Laboratory (NREL). Simulations and a comparative study were carried out of the technologies and potential configurations that meet the needs of these isolated communities. The results showed an optimal solution of HGDS PV-FC batteries with a reduction in the initial cost of the project in about 60% compared to the sizing system only. The HOMER simulated results also indicated that more than 50% of the costs of the PV-FC-battery HDGS regarded the PV system. (author)

  5. Implementation and testing of the use of vegetable oils as fuel diesel generators in the Amazon isolated communities; Implantacao e testes de utilizacao de oleo vegetal como combustivel para diesel geradores em comunidades isoladas da Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Suani Teixeira; Silva, Orlando Cristiano da; Gonzalez Velaquez, Silvia Maria Stortini; Monteiro, Maria Beatriz C.A.; Silotto, Carlos Eduardo Grassi [Centro Nacional de Referencia em Biomassa (CENBIO), Sao Paulo, SP (Brazil)

    2004-07-01

    The project PROVEGAM 'Implantation and test of a unit demonstration of energetic utilization of vegetable oil', tested in operational conditions of field, the functioning of a conventional diesel engine, adapted to operate with palm oil 'in natura' in the community of Vila Soledade, city of Moju, Para State. The Vila Soledade is an isolated community that has, approximately, 700 inhabitants and it's located at one hundred kilometers from the city hall by car and more 30 minutes by boat. The electric energy of this community was previously generated, by a conventional diesel engine, obsolete and very expensive to the community, because the fuel price and the transport of the diesel oil from the city to the community. The PROVEGAM project, installed an electric generation group, MWM TD229, manufactured in Brazil, adapted with a conversion kit to operate with 'in natura' palm oil, working 6 hours per day. Because of the viscosity of the palm oil and its combustion point, it was necessary to heat the vegetable oil before its injection into the engine. The operation begins and finishes with diesel oil, in order to heat the palm oil and to clean possible residues deposited in the interior of the engine. The use of the palm oil justifies itself for being produced in the region, which means that it doesn't have to be imported. Currently, the generating group is working in the community during 5 hours per day with palm oil, and 1 hour per day with diesel oil and it already has more than 1600 hours of testing. The results of this project, so far, have confirmed the conceived premises, and this electric model of generating energy is already recommended to be implemented in other communities in the Amazon region. (author)

  6. Performance of a solid oxide fuel cell with cathode containing a functional layer of LSM/YSZ film; Desempenho de uma celula a combustivel de oxido solido com catodo contendo uma camada funcional de filme LSM/YSZ

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Filipe Oliveira; Domingues, Rosana Z.; Brant, Marcia C.; Silva, Charles L.; Matencio, Tulio [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: filipequiufmg@ufmg.br

    2008-07-01

    Performance of a SOFC may be evaluated by using the AC-Impedance and measuring power (P V x I). The objective of this study was to compare the performance of a fuel cell with LSM as a cathode and another one containing an additional functional composite film LSM/YSZ between the LSM and YSZ. Also it was studied variation in second cell resistance and power according to the temperature, hydrogen flux and operation time. For both cells platinum was used as anode. At 800 deg C was observed, in open current circuit, when the composite layer was introduced a decrease in resistance and high power. These results show an improvement of SOFC cathode performance with the introduction of composite LSM/YSZ layer. The maximum performance of the cell was achieved with 100 mL/min hydrogen flow at 800 deg C. The experiments also showed a performance improvement at 850 deg C. The cell behavior was stable during 318 hours of test. (author)

  7. Performance evaluation of a fuel cell with NiO-YSV anode operating with natural gas; Avaliacao do desempenho de uma celula a combustivel com anodo de NiO YSZ operando com gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Shayenne Diniz da; Vasconcelos, Carmel Suzarte Ayres; Lima, Luiz Rogerio Pinho de Andrade [Universidade Federal da Bahia (UFBa), Salvador, BA (Brazil). Escola Politecnica. Dept. de Ciencia e Tecnologia dos Materiais]. E-mail: shayennedn@yahoo.com.br

    2008-07-01

    Fuel cell is an electrochemical device that converts the chemical energy into electric energy. The natural gas, for its proven improvement in the income of the equipment in relation to other energy ones, has been very used to feed the solid oxide fuel cell (SOFC) in the generation of electric power. Ceramics of Yttria-stabilized zirconia had been used as electrolyte and when supported with nickel oxide they act as anode in the solid oxide fuel cell, due to raised ionic conductivity that these materials present in high temperatures, while lanthanum with strontium and manganite are used as cathode. In the composition of the anode, the concentration of Ni O, acting as catalytic in the YSZ confers high electric conductivity and high electrochemical activity of the reactions, providing the internal reform in the SOFC. In this work, the solid oxide fuel cell, formed by Yttria- stabilized zirconia, nickel oxide, and lanthanum with strontium and manganite were tested in the reform had been prepared samples of electrode/electrolyte for use in SOFC of the natural gas in the presence of low water text, similar condition to the operation of the SOFC, operating in temperatures range from 700 to 800 deg C. This cell also was characterized using the impedance spectroscopy technique. These results allowed the development of components of the current versus voltage. (author)

  8. The new courses of ethanol production in Brazil: an analysis from learning curves; Os novos rumos da producao de alcool combustivel no Brasil: uma analise a partir de curvas de aprendizagem

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Amaro Olimpio [Empresa de Pesquisa Energetica (EPE), Brasilia, DF (Brazil); Pereira, Andre Santos [Centre de Recherche sur Environement et Developement (CIRED), Paris (France); Mendonca, Marco Aurelio [Instituto de Pesquisa Economica Aplicada (IPEA), Brasilia, DF (Brazil); Costa, Ricardo Cunha da [Universidade Federal do Rio de Janeiro (PPE/COPPE/UFRJ), RJ (Brazil). Coordenacao do Programa de Pos-Graduacao em Engenharia. Programa de Pos-Graduacao em Planejamento Energetico

    2008-07-01

    PROALCOOL is known internationally as the most successful biofuel promotion program. Prior analysis of the effectiveness of such a program is fundamental to formulation of public policy, not only in the area of energy, but in all sectors of the economy. The article applies learning curve methodology to evaluate the ethanol market in Brazil in order to give an idea about the effort, in terms of investments, required for its advancement. (author)

  9. Formulation of models for determination of the fuel gas demand and consumption in residential buildings; Formulacao de modelos para determinacao da demanda e consumo de gas combustivel em edificios residenciais

    Energy Technology Data Exchange (ETDEWEB)

    Ilha, Marina Sangoi de Oliveira [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil. Dept. de Hidraulica e Saneamento; Goncalves, Orestes Marracini [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia de Construcao Civil

    1996-07-01

    This work presents models for design flow rate and gas volume determination in residential buildings. First, an experimental investigation, applied on a sample of residential buildings at Sao Paulo, Brazil, is described, which essentially consisted in the filling of a form and measurement of gas volume at one minute interval during 10 days (mean). From this data, it was performed a regression analysis in order to explain design flow rate (demand) and gas volume values (consumption), based on different variables. Models proposed on this work are different from the current applied methodology due to their 'open' approach, that is, involved variables can be explicitly found in formulas. (author)

  10. Project of multiple controller models for the maintenance of air/fuel ratio in natural gas internal combustion motors; Projeto de controladores multiplos modelos para manutencao da relacao ar/combustivel em motores de combustao interna movidos a gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Freitas Junior, Fernando Sousa e; Fleury, Agenor de Toledo [Sao Paulo Univ. SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mails: ffreitas@usp.br; agfleury@ipt.br

    2006-07-01

    The objective of this work is the study of advanced control techniques for the reduction of pollutant gases generated by internal combustion engines powered by natural gas. In this paper three techniques are applied to control the fuel injection and the ignition timing: the Generalized Predictive Control (GPC), the Linear Quadratic Regulator (LQR) and H{infinity} Control by Linear Matrix Inequalities (LMI). To each one of those techniques were developed a multiple model structure seeking to include the vast operation region of the engine. The controller's performance is measured by the efficiency in maintaining the fuel/air ratio around 1% of maximum deviation in relation to the stoichiometric value. The results show the possibility of controlling pollutant emission generated by this kind of engine to conform to international emission standards, improving life quality. (author)

  11. Study of emissions and performance of a CFR-Octane engine with dynamometer by means of natural gas fuel injection; Estudo de emissoes e desempenho de um motor CFR-octano com dinamometro atraves da injecao de gas natural combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Calvao, Alexandre Ortiz

    1994-05-01

    The adaptation and study of the behaviour of an ASTM-CFR-octane engine driven by natural gas is discussed. A detailed investigation of the emission of polluting gases, arising from the burning of the natural gas, was realized. To accomplish these aims, some instruments and devices were used: CFR engine with an eddy current dynamometer; orifice plate meter to measure the fuel mass flow; calibrated nozzle to measure the air mass flow; an CO{sub 2}, CO, NO{sub x}, H C, O{sub 2} emissions meter; thermocouples. The natural gas used during the experimental tests ways injected into the engine's manifold in two different ways: the first one was a simple nozzle injecting natural gas directly into the inlet manifold. The second one used a solenoid valve controlled by an electronic timing device synchronized with the engine's crankcase. The results comparing these two methods of injection indicated a slight fuel reduction can be obtained in the synchronized mode. As concerns the emissions, the results obtained by comparison of the three fuels: gasoline, ethanol and natural gas, showed a significant advantage for natural gas, in the sense that major reductions of the emission index for H C, CO and CO{sub 2} were achieved, with the exception of NO{sub x} , which had its index increased. (author)

  12. Physical-chemical properties of the gasoline-ethanol flex-fuel by infrared adsorption spectroscopy; Caracterizacao fisico-quimica do combustivel flexivel (gasolina + AEHC) por espectroscopia de infravermelho

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Camila Reis; Araujo, Antonio Sousa de [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Quimica. Lab. de Combustiveis e Lubrificantes

    2004-07-01

    Gasoline and ethanol are the components studied in the Flex-Fuel technology, in order to provide an innovative and alternative new option of vehicular fuel. To determine their conformity, these fuels were previously analyzed according to the following ANP regulations: density, alcoholic tenor, octane number and distillation. In order to obtain Flex-Fuel samples, the proportions of 20, 40, 60 and 80 vol% of alcohol in gasoline were mixed and homogenized. The obtained mixtures were submitted to the same analysis for evaluation of the physical-chemical behavior. The physical-chemical characterization of the Flex-Fuel was carried out by infrared spectroscopy, using an equipment Fuel Analyzer, manufactured by Petrospec model GS1000, in agreement with the MB 457, D 2700, D2699 rules, and the obtained data: MON (motor method), RON (method researches), and IAD were compared to the results of a type 'C' gasoline. In this work, infrared (IR) absorption spectroscopy showed to be a good tool to readily estimate the octane number of gasoline-ethanol fuel. From IR spectroscopy, was established a method to derive the octane number from the intensities of absorption bands related to methyl, methylene and aromatic compounds, by considering the absorption groups with C-H stretching vibration. According to the Flex-Fuel technology, the obtained results showed that the addition of moisturized ethanol increases the octane number, for instance, for each 5% of alcohol in gasoline an increase of ca. 2% in the octane was observed. (author)

  13. Fuel performance analysis during an Large Break LOCA in the Angra-1 NPP; Analise do desempenho do combustivel durante um acidente postulado de Perda de Refrigerante Primario por Grande Ruptura (APRPGR) na usina nuclear de Angra-1

    Energy Technology Data Exchange (ETDEWEB)

    Sabundjian, Gaiane; Neves Conti, Thadeu das; Morandini, Claudio J. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-12-01

    The present work shows a comparison between the models and correlation sets used by FURNAS S/A and IPEN/CNEN-SP in the thermal-mechanical analysis of the Angra-1 fuel during a large LOCA. Furnas has adopted the rules of Appendix K of the 10 CFR 50 while IPEN has adopted the FRAP-T6 computer code. (author). 7 refs., 10 figs.

  14. Acid membranes of poly(vinyl alcohol) for direct ethanol fuel cell applications; Membranes acidas de poli(alcool vinilico) para aplicacoes em celulas a combustivel via etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Dutra Filho, Jose C.; Gomes, Ailton S. [Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, RJ (Brazil)], e-mail: asgomes@ima.ufrj.br

    2011-07-01

    Proton-conducting hybrid membranes composed of poly(vinyl alcohol) (PVA), phosphotungstic acid (HPW) and diethylenetriaminepentaacetic acid (DTPA) where prepared. The effect of HPW doping and crosslink with DTPA on the membranes properties such as uptake, pervaporation and proton conductivity was investigated. Uptake and permeated flux decreases with increasing content of HPW and DTPA. Ethanol permeabilities obtained was about two orders of magnitude smaller than Nafion 117. FTIR spectra indicated that HPW was incorporated into the polymer matrix and DTPA acted as crosslink agent. The proton conductivity was in the order of 10-3 S.cm-1 with added 4 wt.% of DTPA and generally increases with the addition of HPW. (author)

  15. Technical and economical aspects of the fuel alcohol production in micro distilleries at Rio Grande do Sul, Brazil; Aspectos tecnicos e economicos da producao de alcool combustivel em microdestilarias no Rio Grande do Sul

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Flavio Dias; Bisognin, Dilson Antonio; Hoffmann, Ronaldo; Jahn, Sergio Luis [Universidade Federal de Santa Maria (UFSM), RS (Brazil)

    2010-07-01

    The increasing of ethanol production at Rio Grande do Sul, Brazil, will occur in small scale, through the microdistilleries installed at the present sugar cane producer regions, characterized by the small properties and familiar manpower. However, that production scale is lack of technical and cost analysis for allowing a better evaluation of the existent scenery at the State or Rio Grande do Sul, Brazil. From the production data of four microdistilleries installed at the Rio Grande do Sul, it is possible to affirm that the income obtained for the substract extraction and fermentation are reasonable (average 70.4 and 82.8, respectively). The distillation, however, posses a low yield (average 65.9%), resulting in a negative impact in the industrial productivity, on the energetic factor and the production cost. The increasing of yield of distillation for a satisfactory value (92.0 %) would result in a increasing of industrial productivity up to 61 % (Case B). So, it is necessary a more technical attention to that step for guarantee the development of the ethanol production activity in a small scale.

  16. Thermohydraulic study of a MTR fuel element aimed at the construction of an irradiation facility; Estudo termohidraulico de um elemento combustivel tipo MTR visando a construcao de um dispositivo de irradiacao

    Energy Technology Data Exchange (ETDEWEB)

    Coragem, Helio Boemer de Oliveira

    1980-07-01

    A thermohydraulic study of MTR fuel element is presented as a basic requirement for the development of an irradiation facility for testing fuel elements. A computer code named 'Thermo' has been developed for this purpose, which can stimulate different working conditions, such as, cooling, power elements and neutron flux, performing all pertinent thermohydraulic calculations. Thermocouples were used to measure the temperature gradients of the cooling fluid throughout the IEAR-1 reactor core. All experimental data are in good agreement with the theoretical model applied in this work. Finally, a draft of the proposed facility and its safety system is presented. (author)

  17. Development of a computational model applied to a unitary 144 cm{sup 2} proton exchange membrane fuel cell; Desenvolvimento de um modelo numerico computacional aplicado a uma celula a combustivel unitaria de 144 CM{sup 2} tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric

    2009-07-01

    This work presents the development of a numerical computer model and methodology to study and design polymeric exchange membrane fuel cell - PEM. For the validation of experimental results, a sequence of routines, appropriate to fit the data obtained in the laboratory, was described. At the computational implementation it was created a new strategy of coupling two 3-dimensional models to satisfy the requirements of the comprehensive model of the fuel cell, including its various geometries and materials, as well as the various physical and chemical processes simulated. To effective assessment of the real cell analogy with numerical model, numerical studies were carried out. Comparisons with values obtained in the literature, characterization of variables through laboratory experiments and estimates from models already tested in the literature were also performed. Regarding the experimental part, a prototype of a fuel cell unit of 144 cm of geometric area was designed, produced and operated at laboratory with the purpose of validating the numerical computer model proposed, with positive results. The results of simulations for the 2D and 3D geometries proposed are presented in the form of polarization curves, highlighting the catalytic layer model based on the geometry of agglomerates. Parametric and sensitivity studies are presented to illustrate the change in performance of the fuel cell studied. The final model is robust and useful as a tool for design and optimization of PEM type fuel cells in a wide range of operating conditions. (author)

  18. Synthesis of precursor the base of indene for polyelectrolyte an membrane production for application in fuel cell; Sintese de precursores a base de indeno para producao de polieletrolitos e membranas para uso em celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Brum, F.J.B.; Laux, F.N.; Haack, M.S.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul. Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    Monomers with vinyl bond can be polymerized via a cationic mechanism using acid catalysts. This study aimed to obtain homo and copolymers of styrene and indene via cationic mechanism and the functionalization of sulfonic groups to the production of membranes for fuel cells. Polymers and poly electrolytes were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and gel permeation chromatography (GPC/SEC). The degree of sulfonation of the polymers was determined by titration and evaluated for these films to the degree of swelling in water, ion exchange capacity and analysis of electrochemical impedance spectroscopy. Membranes prepared with polyindene and PVA were tested in an apparatus of the fuel cell. (author)

  19. Study of heat transfer in a eccentric fuel rods in a non stop planned shutdown of a PWR type reactor; Estudo da transferencia de calor em uma vareta combustivel excentrica, num desligamento nao planejado de um reator do tipo PWR

    Energy Technology Data Exchange (ETDEWEB)

    Affonso, Renato Raoni Werneck; Lava, Deise Diana; Borges, Diogo da Silva; Sampaio, Paulo Augusto Berquo de; Moreira, Maria de Lourdes, E-mail: raoniwa@yahoo.com.br, E-mail: deisedy@gmail.com, E-mail: diogosb@outlook.com, E-mail: sampaio@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    This paper aims to conduct a case study in which the fuel pellets are displaced related to the center coating. Therefore, it will be addressed, first, the verification of computer code, comparing the results obtained with analytical solutions. This check is important so that, at a time later, you can use the program to know the fuel rod behavior and coolant channel.

  20. Polymers and composites synthesis and characterization for application on PEM type fuel cells; Sintese e caracterizacao de polimeros e compositos para aplicacao em celulas a combustivel do tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, Raigenis da Paz; Souza, Daniele Ribeiro; Barreto, Ednardo Gomes; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)]. E-mail: raigenis@gmail.com

    2006-07-01

    The PEM (proton exchanging membrane) type fuel cell presents good potential for the energy production without the residue generation. However, its manufacture presents high costs for commercial application, mainly due to the electrolyte. Sulfonated Peek (polish-ether-ether-ketone) supported or auto immobilized the in a silicone matrix is an interesting alternative as electrolyte for PEM fuel cells. The commercial PEEK in powder form was functionalized with sulfuric acid, giving the SPEEK (Sulfonated PEEK). The membranes were produced by hot pressing the SPEEK immobilized in a silicone matrix produced by the sol-gel process. The membranes obtained were characterized by DRX, FTIR, TGA, MEV, DSC and protonic conductivity measurements. (author)

  1. Vegetable oil as fuel for electric power generation at Rondonia, BR, small agglomerate as way of revenue generation; Oleo vegetal como combustivel para energia eletrica em pequenos aglomerados de Rondonia como forma de geracao de renda

    Energy Technology Data Exchange (ETDEWEB)

    Moret, Artur de Souza [Fundacao Universidade Federal de Rondonia (UNIR), Porto Velho, RO (Brazil)]. E-mail: amoret@unir.br

    2006-07-01

    This text approaches the question energy having as based alternative combustible reference in vegetal oils and the Decentralized Generation of Energy, for attendance of isolated systems and with small load, having as conceptual base the partner-economic-ambient sustain ability, being the economic chain of the entailed and conditional energy to the ambient, social aspects, technician, politicians, financiers and economics. This text intends to demonstrate to the mechanisms used in a research and development project (P and D) for the determination and domain of energy generation, electricity and power, from vegetal oils of suitable oleaginous to the State of Rondonia for a Extractive Reserve. Having as reference the contribution for the local and sustainable development of isolated localities, for the generation of job and income, for the energy self-sufficiency of isolated localities and to make available alternative to the companies of the electric sector of energy availability of isolated communities. (author)

  2. Synthesis and characterization of Pt-Sn-Ni alloys to application as catalysts for direct ethanol fuel cells; Sintese e caracterizacao de ligas de Pt-Sn-Ni para aplicacao como caztalisadores em celulas a combustivel do tipo DEFC

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.L. da; Correa, P.S.; Oliveira, E.L. de; Takimi, A.S.; Malfatti, C.F., E-mail: celia.malfatti@ufrgs.b [Universidade Federal do Rio Grande do Sul (LAPEC/UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica. Lab. de Pesquisa em Corrosao; Radtke, C. [Universidade Federal do Rio Grande do Sul (IQ/UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica

    2010-07-01

    Direct ethanol fuel cells (DEFCs) have been the focus of recent research due its application in mobile energy sources. In order to obtain the maximum efficiency from these systems, it is necessary the total ethanol oxidation, which implies in C-C bond break. Different catalysts described in literature are employed with this intent. This work consists in studying PtSnNi catalysts supported on carbon Vulcan XC72R, to application in DEFCs. Thus, it was used the impregnation/reduction method, varying the atomic proportion among Pt, Sn and Ni. The alloys were characterized by X-Ray Diffraction, Cyclic Voltammetry and Transmission Microscopy. Preliminary results show that predominant structure on the catalysts is the face centered cubic platinum and the densities currents are dependent on the platinum amount. (author)

  3. Assessment of PWR fuel degradation by post-irradiation examinations and modeling in DEGRAD-1 code; Avaliacao da degradacao de combustivel PWR por exames pos-irradiacao e modelagem no codigo DEGRAD-1

    Energy Technology Data Exchange (ETDEWEB)

    Castanheira, Myrthes; Lucki, Georgi; Silva, Jose Eduardo Rosa da; Terremoto, Luis A.A.; Silva, Antonio Teixeira e; Teodoro, Celso A.; Damy, Margaret de A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear]. E-mail: myrthes@ipen

    2005-07-01

    On the majority of the cases, the inquiries on primary failures and secondary in PWR fuel rods are based on results of analysis were made use of the non-destructive examination results (coolant activities monitoring, sipping tests, visual examination). The complementary analysis methodology proposed in this work includes a modeling approach to characterization of the physical effects of the individual chemistry mechanisms that constitute the incubation phase of degradation phenomenon after primary failure that are integrated in the reactor operational history under stationary operational regime, and normal power transients. The computational program called DEGRAD-1 was developed based on this modeling approach. The practical outcome of the program is to predict cladding regions susceptible to massive hydriding. The applications presented demonstrate the validity of proposed method and models by actual cases simulation, which (primary and secondary) defects positions were known and formation time was estimated. By using the modeling approach, a relationship between the hydrogen concentration in the gap and the inner cladding oxide thickness has been identified which, when satisfied, will induce massive hydriding. The novelty in this work is the integrated methodology, which supplements the traditional analysis methods (using data from non-destructive techniques) with mathematical models for the hydrogen evolution, oxidation and hydriding that include refined approaches and criteria for PWR fuel, and using the FRAPCON-3 fuel performance code as the basic tool. (author)

  4. Fission product release model for failed plate-type fuel element and storage under water; Modelo para liberacao de produtos de fissao por placa combustivel falhada e armazenada sob agua

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, L.A.A.; Zeituni, C.A.; Silva, J.E.R. da; Castanheira, M.; Lucki, G.; Silva, A.T. e; Teodoro, C.A.; Damy, M. de A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear]. E-mail: laaterre@ipen.br

    2005-07-01

    Plate-type fuel elements burned-up inside the core of nuclear research reactors are stored mainly under deionized water of storage pools. When cladding failure occurs in such elements, radioactive fission products are released into the storage pool water. This work proposes a model to describe the release mechanism considering the diffusion through a postulated small cylindrical failure. As a consequence, an analytical expression is obtained for the activity released into the water as a function of the total storage time of a failed fuel plate. The proposed model reproduces the linear increasing of {sup 137}Cs specific activity observed in sipping tests already performed on failed plate-type fuel elements. (author)

  5. Obtaining of ceria - samaria - gadolinia ceramics for application as solid oxide fuel cell (SOFC) electrolyte; Obtencao de ceramicas de ceria - samaria - gadolinia para aplicacao como eletrolito em celulas a combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Arakaki, Alexander Rodrigo

    2010-07-01

    Cerium oxide (CeO{sub 2}) when doped with rare earth oxides has its ionic conductivity enhanced, enabling its use as electrolyte for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC), which is operated in temperatures between 500 e 700 degree C. The most effective additives or dopants for ionic conductivity improvement are (samarium oxide - Sm{sub 2}O{sub 3}) and gadolinia (gadolinium oxide - Gd{sub 2}O{sub 3}), fixing the concentration between 10 and 20 molar%. In this work, Ce{sub 0,8}(SmGd){sub 0,2}O{sub 1,9} powders have been synthesized by hydroxide, carbonate and oxalate coprecipitation routes. The hydrothermal treatment has been studied for powders precipitated with ammonium hydroxide. A concentrate of rare earths containing 90wt% of CeO{sub 2} and other containing 51% of Sm{sub 2}O{sub 3} and 30% of Gd{sub 2}O{sub 3}, both prepared from monazite processing, were used as starting materials. These concentrates were used due the lower cost compared to pure commercial materials and the chemical similarity of others rare earth elements. Initially, the coprecipitation and calcination conditions were defined. The process efficiency was verified by ceramic sinterability evaluation. The results showed that powders calcined in the range of 450 and 800 degree C presented high specific surface area (90 - 150 m{sup 2}.g{sup -1}) and fluorite cubic structure, indicating the solid solution formation. It was observed, by scanning electron microscopy, that morphology of particles and agglomerates is a function of precipitant agent. The dilatometric analysis indicated the higher rate of shrinkage at temperatures around 1300-1350 degree C. High densification values (>95% TD) was obtained at temperatures above 1400 degree C. Synthesis by hydroxides coprecipitation followed by hydrothermal treatment demonstrated to be a promising route for crystallization of ceria nano powders at low temperatures (200 degree C). High values of specific surface area were reached with the employment of hydrothermal treatment (about 100 m{sup 2}.g{sup -1}). High density ceramics were obtained at lower temperatures (1400 degree C), compared to those employed for calcined powders. (author)

  6. Fuel densification study about uranium- 7% nanostructured gadolinium (Gd{sub 2}O{sub 3}); Estudo da densificacao do combustivel uranio - 7% gadolinio (Gd{sub 2}O{sub 3}) nanoestruturado

    Energy Technology Data Exchange (ETDEWEB)

    Serafim, Antonio da Costa

    2016-11-01

    The sintering process of UO{sub 2}-Gd{sub 2}O{sub 3} pellets has been investigated in this work for its importance in the nuclear industry and for its complex behavior during sintering. Sintering blockage occurs from 1300 deg C upwards, when densification is shifted toward higher temperatures and the final density obtained is decreased. This research includes the development of nuclear fuel for power reactors in order to increase its efficiency inside the reactor core by raising the burnup. The use of nanosized Gd{sub 2}O{sub 3} was studied in the range from 10 to 30nm, which was added to UO{sub 2}, trying to verify the occurrence of characteristic sintering blockage due to Kirkendall sintering effect observed in previous research. The samples were produced by dry mechanical mixture of UO{sub 2} powder and 7% Gd{sub 2}O{sub 3} (macro- and nanostructured). The powders were compacted and the pellets were sintered at 1700 deg C under H{sub 2} atmosphere. These results indicate that the characteristic blockage during sintering in macrostructured system UO{sub 2}-Gd{sub 2}O{sub 3} occurred in the temperature range of 1300-1500 deg C, which slows down the densification. It was observed a less intense effect when using the nanostructured Gd{sub 2}O{sub 3}; it took place at the temperature of 900 deg C, then facilitating to get an additional densification. The dilatometric tests indicated shrinkage of 22, 18 and 20% respectively in UO{sub 2} pellets, macrostructured UO{sub 2}-7% Gd{sub 2}O{sub 3} and nanostructured UO{sub 2}-7%Gd{sub 2}O{sub 3}. We detected 2% higher shrinkage, when nanostructured Gd{sub 2}O{sub 3} was used instead of macrostructured Gd{sub 2}O{sub 3}, which is used commercially. Then, the nanostructured results showed more adequate density for nuclear fuel usage. (author)

  7. Development and testing of the proton exchange membrane fuel cell (PEMFC) for stationary generation; Desenvolvimento e ensaios de uma celula a combustivel de polimero solido (PEMFC) para geracao estacionaria

    Energy Technology Data Exchange (ETDEWEB)

    Ellern, Mara; Boccuzzi, Cyro Vicente [ELETROPAULO, Sao Caetano, SP (Brazil)], e-mail: mara.ellern@aes.com; Ett, Gerhard; Saiki, Gerson Yukio; Janolio, Gilberto [ELECTROCELL, Sao Paulo, SP (Brazil); Jardini, Jose Antonio [Universidade de Sao Paulo (USP), SP (Brazil)

    2004-07-01

    PEM (Proton Exchange Membrane) fuel cell uses a simple chemical reaction to combine hydrogen and oxygen into water, producing electric current in the process. It works something like reversed electrolysis: at the anode, hydrogen molecules give up electrons, forming hydrogen ions (this process is made possible by the platinum catalyst). The proton exchange membrane allows protons to flow through, but not electrons. As a result, the hydrogen ions flow directly through the proton exchange membrane to the cathode, while the electrons flow through an external circuit. As they travel to the cathode through the external circuit, the electrons produce electrical current. At the cathode, the electrons and hydrogen ions combine with oxygen to form water. In a fuel cell, hydrogen's natural tendency to oxidize and form water produces electricity and useful work. No pollution is produced and the only byproducts are water and heat. The huge advance on materials development combined with the growth demand of lower impact on environment is placing the fuel cells on the top of the most promising technologies world-wide. They are becoming in medium term feasible alternatives for energy generators up to energy plants of few MW. (author)

  8. Study of a fuel cell insertion in a hybrid system for energy generation; Estudo da insercao de celula a combustivel integrada a sistema hibrido de geracao de eletricidade isolado

    Energy Technology Data Exchange (ETDEWEB)

    Vale, Silvio Bispo do; Bezerra, Ubiratan Holanda; Pinho, Joao Tavares; Pereira, Edinaldo Jose da Silva [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica. Grupo de Estudo e Desenvolvimento em Alternativas Energeticas

    2004-07-01

    This paper presents a case study of a fuel cell (FC) insertion in a small hybrid system for energy generation composed by wind (10 kW), photovoltaic (3,2 kW) and diesel (20 kVA) generations, making computer simulations in order to evaluate the contribution of each one of the energy-supply systems involved. This paper intends to contribute for the establishment of parameters to measure the technical and economic viability for using such isolated hybrid systems, trying in the future several combinations of models to hybridize the energy generation in Amazon isolated villages, making easier the use of local energy resources. (author)

  9. Experimental study of a PEM 15 W fuel cell; Influencia das temperaturas de operacao e umidificacao no desempenho de uma celula combustivel tipo 'PEM' de 15 W

    Energy Technology Data Exchange (ETDEWEB)

    Heusi, Daniel S.; Steidel, Paulo S.; Matelli, Jose A. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Lab. de Combustao e Engenharia de Sistemas Termicos (LabCET); Bazzo, Edson [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2004-07-01

    Experimental results are presented for a fuel cell type PEM of 15 W. The influence of the operating temperature, as well as the effect of the humidification temperature in the draining of the gases Hydrogen and oxygen, are considered for analysis. The tests were performed at operating temperature in the range of 30 to 70 deg C and humidification temperature form 30 to 85 deg C. For hydrogen flows fixed to be 200 ml/min and 300 ml/min, as well as for oxygen flow of 165 ml/min, the polarization curves were raised taking into account different combinations of operation and different combinations of humidification temperatures. (author)

  10. Study of a brazilian cask and its installation for PWR spent nuclear fuel dry storage; Estudo de um casco nacional e sua instalacao para armazenagem seca de combustivel nuclear queimado gerado em reatores PWR

    Energy Technology Data Exchange (ETDEWEB)

    Romanato, Luiz Sergio

    2009-07-01

    Spent nuclear fuel (SNF) is removed from the nuclear reactor after the depletion on efficiency in generating energy. After the withdrawal from the reactor core, the SNF is temporarily stored in pools at the same site of the reactor. At this time, the generated heat and the short and medium lived radioactive elements decay to levels that allow removing SNF from the pool and sending it to temporary dry storage. In that phase, the fuel needs to be safely and efficiently stored, and then, it can be retrieved in a future, or can be disposed as radioactive waste. The amount of spent fuel increases annually and, in the next years, will still increase more, because of the construction of new nuclear plants. Today, the number of new facilities back up to levels of the 1970's, since it is greater than the amount of decommissioning in old installations. As no final decision on the back-end of the nuclear fuel cycle is foreseen in the near future in Brazil, either to recover the SNF or to consider it as radioactive waste, this material has to be isolated in some type of storage model existing around the world. In the present study it is shown that dry SNF storage is the best option. A national cask model for SNF as well these casks storage installation are proposed. It is a multidisciplinary study in which the engineering conceptual task was developed and may be applied to national SNF removed from the Brazilian power reactors, to be safely stored for a long time until the Brazilian authorities will decide about the site for final disposal. (author)

  11. Vitrification of nanotoxic waste (Ru) from the production of nano-catalysts for direct ethanol fuel cells; Vitrificacao de nano-residuos toxicos (Ru) provenientes da producao de nano-catalisadores para celulas a combustivel de etanol direto

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.C.; Julio-Junior, O.; Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Nanostructured catalysts have been developed for ethanol directly use in fuel cells, which due to the economic advantages that should have widespread use in the near future. The catalysts for these devices using nano-structured metal are based, where the toxic nature and environmental risks presented by these metals are largely enhanced by nano-dispersion. Thus, the production of nano-catalysts are potentially generating highly hazardous waste for public health and the environment. This study presents the treatment and inertization of ruthenium (Ru) nanoparticles waste containing by the vitrification technique and consequent attainment of silicate glasses for potential commercial use. Compositions were prepared containing up to about 20 wt % of nano-waste by changing the basic composition of glass soda-lime-borosilicate. After the fusion, at a temperature of 1100 deg C, the glasses were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Infra-red in the Fourier transform (FT-IR) techniques. The chemical stability was evaluated by hydrolytic attack test. The glass containing 20 wt % of nano-residue showed a high chemical stability, similar to a usual soda-lime glass. (author)

  12. Preparation, characterization and evaluation of electrocatalysts supported on functionalized carbon black for polymer exchange membrane fuel cell applications; Preparacao, caracterizacao e avaliacao de eletrocatalisadores suportados em carbono funcionalizado para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Marcelo do

    2008-12-18

    The fuel cell technology associated with the growing exigency of low environmental impact energy became prosperous in the world energy scenery. The fuel cell is basically a device that converts directly the chemical energy of a fuel into electrical and thermal energy with a continuous operation by the constant feed of a fuel. Especially, the carbon black Vulcan XC72 is usually employed as an electro catalyst support, and some factors as an accessible and high surface area in order to get maximum particles dispersion, pore size, adequate pore distribution and the presence of functional groups in the carbon black surface are considered fundamental characteristics for an innovative materials development. However, the Vulcan XC72 still reveals insufficient conditions for these purposes. This study consists in the preparation and in the physical chemical characterization of functionalized carbon black by hydrogen peroxide and by polymeric chains with proton conduction properties, and its posterior utilization as electro catalyst support for PEMFC and DMFC application. After the carbon functionalization, an improvement in the carbon black dispersion in water media was observed, a beneficial effect for electro catalyst preparation. It was also observed, that the functional groups and the polymeric chains worked as stabilizers in the particle growing, producing much more homogeneous electrocatalysts, exhibiting smaller average particle size. Especially, in the case of polymeric chains functionalization, a decrease in the ohmic drop was observed for this system, attributed to an improvement in the proton transference. (author)

  13. Environmental analysis of the proton exchange membrane fuel cell on the subject of life cycle assessment; Analise ambiental da celula a combustivel de membrana trocadora de protons sob o enfoque da avaliacao do ciclo de vida

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi

    2006-07-01

    The energy is the fuel of growth and an essential requirement for the socioeconomic development. However, the current production model is based on fossil fuels, considered as threat to man and nature. As for, the relating to the human activities and their effects on the environment, they are handled by the implementation of a more rigid model of environmental control and the mobilization of the society in favor of technologies with less energy impact. In view of this scenario, the Proton Exchange Membrane Fuel Cell - PEMFC has been recognized as a key for the vital need of a clean and efficient energy. Considering the conventional power generation system, their advantages during usage configure its application as an ideal option for several utilities, especially in the mobile sector. Even though, the focus on several environmental evaluations in energy systems is referred back to the initial stage of it use, the employment relating to production of the system and to final destination should be considered, since these also present impacts. In the case of PEMFC, their previous and subsequent phases of use are issues related to the platinum catalysts, which indicates an environmental importance that cannot be overlooked. In this sense, the Life Cycle Assessment has been used to understand and to question the risks and opportunities that are associated to certain product, starting from a systemic concept of their relationships with the environment. It is precisely in this context that the present research intends to present its major contribution, starting from an exploratory study towards the its objectives to provide an environmental analysis of such technology linked to post stage of powder-use of the membrane electrode assembly - MEA, concerning the platinum catalysts, on the subject of Life Cycle Assessment - LCA. To attain such aim, the relationships between energy, environment and development are presented and discussed, as well as, the Fuel Cell technology and the current studies on LCA of PEMFC. Several questions raised up on this issues have contributed in the development of a method of recuperating the PEMFC catalysts and, particularly, for its subsequent environmental evaluation. Among significant results are the importance of LCA, out lined as useful tool for perceiving the weight of environmental matters concerning the platinum and its subsidy strategies relating to the development, consolidation and to the innovation of PEMFC. (author)

  14. Development and scale-up of the production process of NovoCell fuel cells; Desenvolvimento e 'scale-up' do processo de producao de celulas a combustivel NovoCell

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Dayse Caldas de; Souza, Adler de; Ferreira, Valdemar Stelita [NovoCell Sistemas de Energia S.A., Santa Barbara D' Oeste, SP (Brazil)]. E-mail: dayse.azevedo@novocell.ind.br

    2008-07-01

    Fuel cells present the potentiality to substitute the engines of internal combustion in vehicles and to supply energy for stationary use. This potentiality, however, not yet reflected in its introduction in the market with regular lines of production, because of its high cost and lack of criteria that demonstrate its reliability and durability. These subjects are the main goals of the programs of development of fuel cells worldwide. NovoCell is a Brazilian company whose objective is to develop and to produce hydrogen/air fuel cells for stationary generation. All the project is guided by the use of technologies/processes and materials that allow production in large scale and to a competitive cost, giving support to a continuous program of innovation and development of the product. In this work the technological solutions developed by the company are presented. (author)

  15. Eco-compatibility in the Brazilian energy matrix: biodiesel fuel can be considered environmentally friendly?; Eco-compatibilidade na matriz energetica brasileira: o biodiesel pode ser considerado como combustivel ambientalmente correto?

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Iracema Andrade; Santos, Jarsia Melo dos; Cruz, Andrea Cristina da; Leite, Maria Bernadete Neiva Lemos [Faculdade de Tecnologia e Ciencias, Salvador, BA (Brazil)], e-mail: iracema@ftc.br; Pereira, Solange Andrade; Nascimento, Mauricio Andrade [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Biologia

    2008-07-01

    Based on the law 11.097/05, Brazil begins the compulsory use of biodiesel from 2008, persuading the compliance of economical, technological, social and environmental objectives. The country uses 40 billions litters of diesel per year, 15% to 17% imported, which represented in 2007, a cost superior to two billion dollars. The addition of biodiesel to diesel from 2%, 5% to 20% (limit proved as technically secure), besides providing economical and social benefits, represents environmental gains, due to emissions reduction in relation to diesel fossil. However, besides the acrolein, which can result from the burnt of possible remaining glycerin in biodiesel, the soluble fractions of this biofuel and the effluents generated during its productive processes may cause possible pollution in soil and water bodies. Eco toxicological information of co-products is incomplete, and due to technical and economical restraints for the use of ethanol, methanol is mostly used for the transesterification process of biodiesel production, even though its toxicological properties are already biodiesel/year. However, the estimated production capacity is supposed to reach 3,8 billions L by 2009, what may represent environmental constraints. The present work does not discuss all the ecological risks associated to the biodiesel productive chain. It aims to determine the toxicity of the soluble water fraction (FSA) of three different types of biodiesel: castor base oil (methylic route and homogeneous basic catalysis - NaOH), 'dende' base oil (methylic route and acid catalysis) and residual cooking oil OGR-biodiesel (methylic route and acid and basic catalysis), using as organism-test (Echinometra lucunter) and, as biochemical biomarker, the activity of acid phosphatase, measured in hepatocytes of exposed fishes (Oreochromis niloticus). The results showed that the FSA of mamona (castor oil) biodiesel was the most toxic (5,0 mU/mg), followed by OGR (3,9 mU/mg) and dende biodiesel (2,4 mU/mg), when compared to control (1,6 mU/mg). The results obtained from the early life- stage-test showed a similar trend, the mamona biodiesel being the most toxic (EC50 2.45%), followed of the OGR - residual oil (EC50 = 8.06%) and dende biodiesel (EC50 = 22.75%). The significance of these findings shall be considered for energetic planning. (author)

  16. Development of a high density fuel based on uranium-molybdenum alloys with high compatibility in high temperatures; Desenvolvimento de um combustivel de alta densidade a base das ligas uranio-molibdenio com alta compatibilidade em altas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Fabio Branco Vaz de

    2008-07-01

    This work has as its objective the development of a high density and low enriched nuclear fuel based on the gamma-UMo alloys, for utilization where it is necessary satisfactory behavior in high temperatures, considering its utilization as dispersion. For its accomplishment, it was started from the analysis of the RERTR ('Reduced Enrichment for Research and Test Reactors') results and some theoretical works involving the fabrication of gamma-uranium metastable alloys. A ternary addition is proposed, supported by the properties of binary and ternary uranium alloys studied, having the objectives of the gamma stability enhancement and an ease to its powder fabrication. Alloys of uranium-molybdenum were prepared with 5 to 10% Mo addition, and 1 and 3% of ternary, over a gamma U7Mo binary base alloy. In all the steps of its preparation, the alloys were characterized with the traditional techniques, to the determination of its mechanical and structural properties. To provide a process for the alloys powder obtention, its behavior under hydrogen atmosphere were studied, in thermo analyser-thermo gravimeter equipment. Temperatures varied from the ambient up to 1000 deg C, and times from 15 minutes to 16 hours. The results validation were made in a semi-pilot scale, where 10 to 50 g of powders of some of the alloys studied were prepared, under static hydrogen atmosphere. Compatibility studies were conducted by the exposure of the alloys under oxygen and aluminum, to the verification of possible reactions by means of differential thermal analysis. The alloys were exposed to a constant heat up to 1000 deg C, and their performances were evaluated in terms of their reaction resistance. On the basis of the results, it was observed that ternary additions increases the temperatures of the reaction with aluminum and oxidation, in comparison with the gamma UMo binaries. A set of conditions to the hydration of the alloys were defined, more restrictive in terms of temperature, time and pre-treatment to stabilize the gamma structure. The addition of a bit low ternary excess and formation of an intergranular phase, the increase in stability, it was demonstrated that there is not a damage in the formation of their powders.(author)

  17. Impacts of fuel oil substitution by natural gas in a pipeline network scheduling; Impactos da substituicao do oleo combustivel por gas natural na programacao de uma rede de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Souza Filho, Erito M.; Bahiense, Laura; Ferreira Filho, Virgilio J.M. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil)

    2012-07-01

    In recent decades, due to the advancement and computational methods for solving optimization problems, the number of articles addressing the scheduling of products has grown. The mathematical models developed have proved useful to schedule from a single pipeline with multiple products to complex networks of multiple pipelines. Moreover, the planning of these activities is of even greater importance when considering the existence of new environmental requirements to be applied to production and marketing of petroleum products. An example of this paradigm shift is the reduction in fuel oil consumption due to increased share of natural gas in the Brazilian energy matrix. In this context, this paper proposes a mathematical model to obtain feasible solutions for problems of scheduling a network of pipelines considering replacing all or part of the demand for fuel oil to natural gas. We tested the model on three real instances of a multi commodity network consists of 4 terminals, 4 refineries and 8 unidirectional pipelines, considering a planning horizon of one week. (author)

  18. Study of internal exposure to uranium compounds in fuel fabrication plants in Brazil; Estudo da exposicao interna a compostos de uranio na fabricacao do elemento combustivel nuclear no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maristela Souza

    2006-07-01

    The International Commission on Radiological Protection (ICRP) Publication 66 and Supporting Guidance 3) strongly recommends that specific information on lung retention parameters should be used in preference to default values wherever appropriate, for the derivation of effective doses and for bioassay interpretation of monitoring data. A group of 81 workers exposed to UO{sub 2} at the fuel fabrication facility in Brazil was selected to evaluate the committed effective dose. The workers were monitored for determination of uranium content in the urinary and faecal excretion. The contribution of intakes by ingestion and inhalation were assessed on the basis of the ratios of urinary to fecal excretion. For the selected workers it was concluded that inhalation dominated intake. According to ICRP 66, uranium oxide is classified as insoluble Type S compound. The ICRP Supporting Guidance 3 and some recent studies have recommended specific lung retention parameters to UO{sub 2}. The solubility parameters of the uranium oxide compound handled by the workers at the fuel fabrication facility in Brazil was evaluated on the basis of the ratios of urinary to fecal excretion. Excretion data were corrected for dietary intakes. This paper will discuss the application of lung retention parameters recommended by the ICRP models to these data and also the dependence of the effective committed dose on the lung retention parameters. It will also discuss the problems in the interpretation of monitoring results, when the worker is exposed to several uranium compounds of different solubilities. (author)

  19. Hydrogen production through allothermal ethanol reforming for fuel cells application: first generation prototype; Producao de hidrogenio atraves da reforma-vapor do etanol para aplicacoes em celulas a combustivel: prototipo de primeira geracao

    Energy Technology Data Exchange (ETDEWEB)

    Marin Neto, Antonio Jose; Silva, Ennio Peres da; Camargo, Joao Carlos; Neves Junior, Newton Pimenta; Pinto, Cristiano da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Lab. de Hidrogenio; Pinto, Cristiano da Silva [Centro Nacional de Referencia em Energia do Hidrogenio, Campinas, SP (Brazil)

    2004-07-01

    This paper describes preliminary results obtained with the allothermal ethanol reforming system for synthesis gas (syn-gas) production and hydrogen upgrading and purification for fuel cell applications. The system was designed to supply hydrogen to a 500 W PEM (Proton Exchange Membrane) fuel cell, with an electrical efficiency of 45%, which requires approximately 0.45 m3.h-1 of hydrogen, with a maximum carbon monoxide concentration of 20 {mu}mol.mol-1 (ppm). The study was performed changing the operation temperature and analyzing the resulting syn-gas through gas chromatography for a specific catalyst. This catalyst was tested up to 700 deg C, 1 bar and fixed stoichiometric steam to carbon ratio. The syn-gas, before carbon monoxide shift reactor implementation, was submitted to a two-bed-three-segments purification step composed of chemical and physical molecular sieves for hydrogen purification. The carbon monoxide shift reactor (water gas shift reactor) is under development to improve the efficiency-to-hydrogen and maximize the life of the purification bed. The final results also include a discussion about possible reactions involved in ethanol steam-reforming for such catalyst. (author)

  20. Evaluation of composition of natural gas used as a fuel in pickups in motor racing; Avaliacao da composicao do gas natural utilizado como combustivel em pickups em corridas automobilisticas

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Fatima D.; Silva, Haroldo F. da; Leal, Glaucia P.; Freire, Luiz Gustavo de M. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Balthar, Alcides R.; Bayer, Marcilio de M. [Centro de Tecnologias do Gas (CTGAS), Natal, RN (Brazil)

    2004-07-01

    Concerned with the quality of their products, PETROBRAS could not have a different attitude in relation to the natural gas vehicular (NGV). For this, the compositions of natural gases used in the pickup of PETROBRAS Pickup Racing have been determined. In the tests accomplished in the race tracks, after the trainings and after the races, a portable Micro gas chromatograph, model Agilent 3000A have been used. This equipment have tree thermal conductivity detectors, columns appropriate to determine the components of the natural gas (N{sub 2}, CO{sub 2}, CH{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 8}, C{sub 4}H{sub 10} and C{sub 5+}, at 70 deg C) and also the presence of O{sub 2}, at 110 deg C. The gas chromatograph is controlled by a laptop that calculates the final composition of the NGV and the calorific value. The tests proved that the composition of NGV was similar of a standard natural gas. This proved that the performance of the pickups, in the race, is related to the quality of the natural gas used. This project was developed by PETROBRAS/CENPES, CTGAS and RedeGasEnergia (author)

  1. Energetic-economical analysis of a stationary for energy generation with fuel cells and natural gas reforming; Analise energetico-economica de um sistema estacionario de geracao de energia com celulas a combustivel e reforma de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Jose Geraldo de Melo; Silva Junior, Fernando Rodrigues; Silva, Cristiane Abrantes da; Soares, Guilherme Fleury Wanderley; Lopes, Francisco da Costa; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: furtado@cepel.br; Codeceira Neto, Alcides [Companhia HidroEletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Power systems based on fuel cells have been considered for residential and commercial applications in energy Distributed Generation (DG) market as these systems can minimize their acquisition, installation and operation high costs. In this work we present an experimental analysis of a power generation system formed by a 5 kW proton exchange membrane fuel cell unit and a natural gas reformer (fuel processor) for hydrogen production, of the CEPEL's Fuel Cell Laboratory. It was determined the electrical performance of the cogeneration system in function of the design and operational power plant parameters. Additionally, it was verified the influence of the activation conditions of the fuel cell electrocatalytic system on the system performance. It also appeared that the use of hydrogen produced from the natural gas catalytic reforming provided the system operation in excellent electrothermal stability conditions resulting in increase of the energy conversion efficiency and of the economicity of the cogeneration power plant. The maximum electrical efficiency achieved was around 38% and in all power range unit operated with average potential per single fuel cell higher than 0.60 V. (author)

  2. Thermodynamical simulation for solid oxide (SOFC) type fuel cells with ethanol direct internal reforming; Simulacao termodinamica para celulas a combustivel do tipo SOFC com reforma interna direta do etanol

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Aline Lima da; Malfatti, Celia de Fraga; Heck, Nestor Cezar [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM)]. E-mail: als14br2000@yahoo.com.br; Mello, Celso Gustavo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Quimica (PPGEQ); Halmenschlager, Cibele Melo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM). Lab. de Materiais Ceramicos

    2008-07-01

    In SOFC, high operative temperature allows the direct conversion of ethanol into H{sub 2} to take place in the electrochemical cell. Direct internal reforming of ethanol, however, can produce undesirable products that diminish system efficiency and, in the case of carbon deposition over the anode, may occur the breakdown of the electrode. In this way, thermodynamic analysis is fundamental to predict the product distribution as well as the conditions favorable for carbon to precipitate inside the cell. Equilibrium determinations are performed by the Gibbs energy minimization method, using the GRG algorithm. Thermodynamic conditions for carbon deposition were analyzed, in order to establish temperature ranges and H{sub 2}O/ethanol ratios where carbon precipitation is not feasible. A mathematical relationship between Lagrange multipliers and carbon activity is presented, unveiling the carbon activity in atmosphere. The effect of the type of solid electrolyte (O{sup 2-} or H{sup +} conducting) on carbon formation is also investigated. The results of this work are in agreement with previous results reported in literature using the stoichiometric method. (author)

  3. Interpretation of the results from individual monitoring of workers at the Nuclear Fuel Fabrication Facility, Brazil; Interpretacao de resultados de monitoracao individual interna da Fabrica de Combustivel Nuclear - FCN

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marcelo Xavier de

    2005-07-01

    In nuclear fuel fabrication facilities, workers are exposed to different compounds of enriched uranium. Although in this kind of facility the main route of intake is inhalation, ingestion may occur in some situations, and also a mixture of both. The interpretation of the bioassay data is very complex, since it is necessary taking into account all the different parameters, which is a big challenge. Due to the high cost of the individual monitoring programme for internal dose assessment in the routine monitoring programmes, usually only one type of measurement is assigned. In complex situations like the one described in this study, where several parameters can compromise the accuracy of the bioassay interpretation it is need to have a combination of techniques to evaluate the internal dose. According to ICRP 78 (1997), the general order of preference of measurement methodologies in terms of accuracy of interpretation is: body activity measurement, excreta analysis and personal air sampling. Results of monitoring of working environment may provide information that assists in the interpretation on particle size, chemical form, solubility and date of intake. A group of fifteen workers from controlled area of the studied nuclear fuel fabrication facility was selected to evaluate the internal dose using all different available techniques during a certain period. The workers were monitored for determination of uranium content in the daily urinary and faecal excretion (collected over a period of 3 consecutive days), chest counting and personal air sampling. The results have shown that at least two types of sensitivity techniques must be used, since there are some sources of uncertainties on the bioassay interpretation, like mixture of uranium compounds intake and different routes of intake. The combination of urine and faeces analysis has shown to be the more appropriate methodology for assessing internal dose in this situation. The chest counting methodology has not shown appropriate to be applied in the routine individual monitoring programme. The intake estimated is a primary indicator of the potential exposure of a worker to airborne materials and can provide early information on changes in workplace conditions. The uncertainty associated to this kind of measurement is much higher compared to in vitro bioassay. (author)

  4. Neutron spectrometry and dosimetry with neural networks and Bonner spheres: a study to reduce the spheres number; Espectrometria y dosimetria neutronica con redes neuronales y esferas Bonner: un estudio para reducir el numero de esferas

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza G, J. G.; Martinez B, M. R.; Leon P, A. A.; Hernandez P, C. F.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Mendez, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain); De Sousa L, M. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, MG (Brazil)

    2016-10-15

    For neutron spectrometry and neutron dosimetry, the Bonner spheres spectrometric system has been the most widely used system, however, the number, size and weight of the spheres composing the system, as well as the need to use a reconstruction code and the long periods of time used to carry out the measurements are some of the disadvantages of this system. For the reconstruction of the spectra, different techniques such as artificial neural networks of reverse propagation have been used. The objective of this work was to reduce the number of Bonner spheres and to use counting speeds in a reverse propagation neural network, optimized by means of the robust design methodology, to reconstruct the neutron spectra. For the design of the neural network we used the neutron spectra of the IAEA and the response matrix of the Bonner spheres with {sup 6}LiI(Eu) detector. The performance of the network was compared; using 7 Bonner spheres against other cases where only 2 and one sphere are used. The network topologies were trained 36 times for each case keeping constant the objective error (1E(-3)), the training algorithm was trains cg and the robust design methodology to determine the best network architectures. With these, the best and worst results were compared. The results obtained using 7 spheres were similar to those with the 5-in sphere, however is still in an information analysis stage. (Author)

  5. Genetic algorithms used to optimize an artificial neural network design used in neutron spectrometry; Algoritmos geneticos utilizados para optimizar un diseno de red neuronal artificial usado en espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J. M.; Vega C, H. R., E-mail: tarcicio70@yahoo.co.uk [Universidad Autonoma de Zacatecas, Av. Lopez Velarde 117, 98600 Zacatecas, Zac. (Mexico)

    2016-10-15

    Artificial neural networks (Ann) are widely used; it which consist of an input layer, one or more hidden layers and an output layer; these layers contain neurons and each has connections called weights, where the knowledge are allowed and let to Ann solve problems proposed. These Ann is used to reconstruction of the energy spectrum of neutrons from count rates and develop Bonner sphere neutron dosimetry. Currently, we have developed Ann with high performance and generalization ability. Determine your optimal architecture is usually a difficult task, an exhaustive search of all possible combinations of parameters is rarely possible further training of the neural network with random initial weights can cause two major drawbacks: it can stuck in local minima or converge very slowly. In this project it will be used Genetic Algorithms (Ga); which are based on the principle or analogy of evolution through natural selection and has shown to be very effective in optimizing complex search functions and large spaces or to find a near optimal overall efficiency. The aim is to decrease the architecture in number of hidden neurons and therefore the total number of connections is reducing. The benefits obtained by optimizing the network are that the number of connections would be considerably smaller and thus the computational complexity, hardware integration, resources will be lower such that will allow to be even more viable implemented. To use the Ga three problems must be solve: 1) coding the problem into chromosomes. 2) Construct a fitness function. 3) Proper selection of genetic operators; crossover, selection, mutation. As a result, the scientific knowledge obtained can to be applied to similar problems having a reference parameters used and their impact on the optimization would to be generated. It concluded that the input layer and output are subject to the problem; the Ga propose the optimal number of neurons in the hidden layer without losing the quality of the results. (Author)

  6. Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries; Determinacao de cobre, cromo e arsenio em madeira preservada (Eucalyptus sp.) pelas espectrometrias de fluorescencia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Junior, Sergio Matias

    2014-07-01

    Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

  7. Selection and optimization of spectrometric amplifiers for gamma spectrometry: part II - linearity, live time correction factors and software; Seleccion y optimizacion de amplificadores espectrometricos para espectrometria gamma: parte II - linealidad, tiempo vivo, software

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Marco Antonio Proenca Vieira de; Pugliesi, Reinaldo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    The objective of the present work was to establish simple criteria to choose the best combination of electronic modules to achieve an adequate high resolution gamma spectrometer. Linearity, live time correction factors and softwares of a gamma spectrometric system composed by a Hp Ge detector have been studied by using several kinds of spectrometric amplifiers: Canberra 2021, Canberra 2025, Ortec 673 and Tennelec 244 and the MCA cards Ortec and Nucleus. The results showed low values of integral non-linearity for all spectrometric amplifiers connected to the Ortec and Nucleus boards. The MCA card should be able to correct amplifier dead time for 17 kcps count rates. (author)

  8. Biblioteca de perfis moleculares de bactérias aeróbias formadoras de endósporos obtidos por espectrometria de massa MALDI-TOF, com sistema de qualidade

    OpenAIRE

    Bezerra, Flávia Porto Carreiro Araújo

    2016-01-01

    Bactérias aeróbias formadoras de endósporos (Bafes) possuem a capacidade de se diferenciarem em esporos notavelmente resistentes e apresentarem grande diversidade fisiológica, características que conferem importância ambiental, biotecnológica e sanitária, entre outras. A Coleção de Bafes (CBafes) compreende 154 linhagens (SDF) selvagens de Bafes isoladas do solo do Distrito Federal, Brasil, analisadas segundo abordagem polifásica, que envolve a caracterização fenotípica, genotípica, complemen...

  9. A gamma-Ray spectrometer system for low energy photons by coupling two detectors; Un sistema de espectrometria gamma de fotones de baja energia mediante acoplamiento de dos detectores

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.; Palomares, J.; Romero, L.; Travesi, A.

    1986-07-01

    This report describes the study performed to obtain a composite (sun uma) spectrum from a Low Energy Gamma Spectrometry System by coupling two planar Germanium detectors. This disposition allows to obtain a high counting efficiency for the total system. It shows the improvement achieved by the synthetic spectrum which is obtained by adding the two original spectra through the LULEPS code. This code corrects the differences (channel/energy) between both two spectra before performing the addition. (Author) 6 refs.

  10. Dose calculation for {sup 40}K ingestion in samples of beans using spectrometry and MCNP; Calculo de dose devido a ingestao de {sup 40}K em amostras de feijao utilizando espectrometria e MCNP

    Energy Technology Data Exchange (ETDEWEB)

    Garcez, R.W.D.; Lopes, J.M.; Silva, A.X., E-mail: marqueslopez@yahoo.com.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/PEN/UFRJ), Rio de Janeiro, RJ (Brazil). Centro de Tecnologia; Domingues, A.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica; Lima, M.A.F. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Biologia

    2014-07-01

    A method based on gamma spectroscopy and on the use of voxel phantoms to calculate dose due to ingestion of {sup 40}K contained in bean samples are presented in this work. To quantify the activity of radionuclide, HPGe detector was used and the data entered in the input file of MCNP code. The highest value of equivalent dose was 7.83 μSv.y{sup -1} in the stomach for white beans, whose activity 452.4 Bq.Kg{sup -1} was the highest of the five analyzed. The tool proved to be appropriate when you want to calculate the dose in organs due to ingestion of food. (author)

  11. Decision Threshold and Detection Limit in Spectrometric Measurements. Part 1: Application to Gamma Spectrometry; Umbral de Decision y Limite de Deteccion en Medidas Espectrometricas. Parte 1: Aplicacion a la Espectrometria Gamma

    Energy Technology Data Exchange (ETDEWEB)

    Perez, C.; Gasco, C.; Lopez, M.A.

    2010-03-03

    This report summarised the author's lecture of the advanced gamma spectrometry course organised by CIEMAT. The characteristic limits determination in gamma spectrometry generally is obtained through the programming that the trade marks offers to the client with the objective of the automatic calculation of the activity concentrations existing in a sample. In this report, the examples shown in the ISO 11929 standard are compared to the programming realised by Genie 2k for determining characteristic limits. The main difference of both is located in the uncertainty calculations due to the efficiency calibration that is considered by ISO and not by Genie 2K. Through implementation in the software developed by trade marks will be possible to introduce this uncertainty and to assimilate to the calculation done by ISO 11929. In the second part of this report will be analyzed the more complicated samples of this application as counting in a whole body counter (following ISO-28218 about Performance Criteria for radio bioassay), multiplet, overlapping, addition of several peaks for obtaining the activity concentration, etc. (Author) 19 refs.

  12. Detecção de resíduos de enrofloxacina por ensaio imunoenzimático e cromatografia líquida acoplada à espectrometria de massas em ovos comerciais de galinha após tratamento

    Directory of Open Access Journals (Sweden)

    R. Gouvêa

    2014-12-01

    Full Text Available A enrofloxacina é um dos antimicrobianos mais utilizados na avicultura industrial, e a deposição de resíduos em produtos avícolas, como os ovos, são de grande importância para a saúde pública. Na legislação brasileira não existe padronização do período de carência para o seu uso na produção avícola e não há Limite Máximo de Resíduo (LMR fixado para enrofloxacina em ovos. Neste estudo, foi utilizado o kit de ELISA comercial (Bioo Scientific(r e a LC-MS/MS na pesquisa de enrofloxacina em ovos de 30 galinhas tratadas previamente via água de bebida, com 10mg/kg de enrofloxacina, durante cinco dias. Seis ovos foram coletados diariamente e analisados durante o tratamento e após a sua suspensão, durante 15 dias. A deposição de resíduos obteve níveis máximos no quinto dia de tratamento das aves, declinando gradativamente até não ser detectada a partir do nono dia de suspensão do tratamento. Considerando como base o LMR de 100µg/kg fixado pelo Brasil para tecidos comestíveis de aves e pela União Europeia para músculo, gordura e pele, após seis dias de suspensão do tratamento, os níveis de resíduos foram inferiores a esse limite, tendo como médias 37,43µg/kg na LC-MS/MS e 14,731µg/kg no ELISA. Dentro das condições deste estudo, um período de carência de seis dias seria mais adequado para utilização dos ovos para consumo humano. Foram detectados valores de resíduos nos ovos menores no ELISA em relação à LC-MS/MS para a mesma amostra, mas os dois métodos apresentaram concordância estatística entre si. A LC-MS/MS é o teste recomendado pela legislação brasileira para a análise de resíduos em alimentos; entretanto, pelos resultados obtidos, o kit de ELISA utilizado também pode ser aplicado na detecção de resíduos de enrofloxacina em ovos, com as vantagens de rapidez e simplicidade.

  13. AVALIAÇÃO DE MÉTODOS DE SOLUBILIZAÇÃO PARA DETERMINAÇÃO DE METAIS EM GLICERINA PROVENIENTE DA PRODUÇÃO DE BIODIESEL POR TÉCNICAS DE ESPECTROMETRIA ATÔMICA

    Directory of Open Access Journals (Sweden)

    Caroline D Clasen

    2015-01-01

    Full Text Available This paper describes the evaluation of simple and fast solubilization methods for the determination of Ca, Mg, and K in glycerin samples from biodiesel production by atomic spectrometry. The solubilization in water was compared with two other methods: solubilization in formic acid and solubilization in ethanol. Using solubilization in water, determination of the three analytes was possible; the values of limits of detection for Ca, K, Mg were 0.31, 0.06, and 0.16 mg kg−1, respectively. Because no adequate reference material was available, the accuracy was evaluated by assessing the recoveries tests with both solubilization methods; the evaluation ranged from 90% to 115%, with values of relative standard deviation >8%, indicating good accuracy of the measure. Four crude glycerin samples obtained from biodiesel plants of Rio Grande do Sul were analyzed after treatment with the different methods of solubilization, and the obtained results of Ca, Mg, and K concentration were in agreement with the values obtained from both solubilization methods. Therefore, solubilization in water is concluded to be a simpler, faster, and viable method for sample preparation of glycerin.

  14. Radioecological studies at the National Center of Accelerators based on the use of the accelerator mass spectrometry; Estudios radioecologicos en el Centro Nacional de Aceleradores basados en el uso de la Espectrometria de Masas con Acelerador (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo, E.; Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-03-01

    Since mid-2006 a compact Accelerator Mass Spectrometry (AMS) of 1 MV, Tandetron type, named SARA (Spanish Accelerator for Radionuclide Analysis) is installed at the National Accelerator Centre in Seville. After an initial period, to set-up the equipment and to study its capability to detect the long-lived radionuclides {sup 1}4C, {sup 1}0B, {sup 2}6Al, {sup 1}29I and plutonium isotopes ({sup 2}39Pu and {sup 2}40Pu) compared to other techniques of mass spectrometry (MS), numerous research lines in fields as diverse as archaeology, geology, palaeontology, oceanography, internal dosimetry, astrophysics and characterization of radioactive waste, among others, have been opened. In particular, since 2008 numerous contributions in the field of Radioecology have been done, based in the measurements of {sup 1}29I and Pu isotopes ({sup 2}39Pu and {sup 2}40Pu). In this article, some of these radioecological researches are summarized and presented, with special emphasis on showing that its accomplishment requires the application of the AMS technique, to be able to achieve sensitivities and detection limits which are impossible to reach when radiometric and mass spectrometry conventional techniques are applied. (Author) 13 refs.

  15. Antocianinas em extratos vegetais: aplicação em titulação ácido-base e identificação via cromatografia líquida/espectrometria de massas

    Directory of Open Access Journals (Sweden)

    Wesson Guimarães

    2012-01-01

    Full Text Available Anthocyanins extracted from picao, quaresmeira, petunia, flamboyant, purple ipe, lobeira, pata de vaca, jaboticaba, purple cabbage and jambul were evaluated as natural acid-base indicators. Anthocyanins in extracts were identified using HPLC/MS. Clear, rapid change in color at final-point titration was observed for extracts but only picao showed strong change in pH. Indirect determination of carbonate in limestone using a natural indicator was performed and results compared with phenolphthalein indicator and potentiometer titration. Optimal results were obtained with picao but other extracts showed good accuracy and precision.

  16. Validation the quantification of beta emitters activity in urine by scintillation spectrometry in the liquid phase; Validacion de la cuantificacion de actividad de emisores beta en orina mediante espectrometria de centelleo en fase liquida

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, I.; Hernandez, C.; Benito, P.; Lopez, C.

    2013-07-01

    In this paper the methodology used in the validation of the technique for quantifying activity of some beta emitters in urine ({sup 3}H, {sup 1}4C, {sup 3}5S, {sup 3}2P and {sup 9}0Sr) by scintillation spectrometry Liquid Phase (Liquid Scintillation Counting, LSC) is described in bio elimination Laboratory Service CIEMAT Radiation Dosimetry accredited since last year for carrying out assays measure radiation dose based on ISO forth above. (Author)

  17. Characterization of a gamma spectrometry monitor LaBr{sub 3} automatic stations for environmental monitoring; Caracterizacion de un monitor de espectrometria gamma de LaBr{sub 3} para las estaciones automaticas de vigilancia ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, A.; Salvador-Castineria, P.; Roig, M.; Fernandez-Varea, J. M.; Padro, A.

    2011-07-01

    The Institut de Techniques Energetiques (INTE) of the Universitat Politecnica de Catalunya (UPC) is collaborating with the German Radiation Protection (BfS) in order to characterize LaBr{sub 3} detector developed by the BfS for future installation of monitoring networks automatic. This paper presents the results obtained with the monitor installed on the roof of the premises of INTE South Campus located in Barcelona and Monte Carlo simulations that complement its characterization.

  18. Development of a gamma ray spectrometry software for neutron activation analysis using the open source concept; Desenvolvimento de um software de espectrometria gama para analise por ativacao com neutrons utilizando o conceito de codigo livre

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, Silvio Rogerio de

    2008-07-01

    This study developed a specific software for gamma ray spectra analysis for researchers of the Neutron Activation Laboratory (LAN), which was named SAANI (Instrumental Neutron Activation Analysis Software). The LAN laboratory of the Institute for Research and Nuclear Energy (IPEN-CNEN/SP), uses a multielemental analytical technique, based on irradiation of a sample by a flux of neutrons from a nuclear reactor, which induces radioactivity. The sample is then placed in a gamma-ray spectrometer, to obtain the spectrum. With free software philosophy in mind, this software will replace the existing software VISPECT / VERSION 2. The new software's main features are: a friendlier interface; easier standardization procedure carried out by LAN staff and researchers; adapted to the use of plug technology; multi platform and code free. The software was developed using the programming Python language, the library Trolltech Qt graphics and some of their scientific extensions. Preliminary results using the SANNI software were compared to those obtained with the existing software and were considered good. There were some errors in accuracy during the implementation of the software. The SAANI software has been installed in selected computers to be used for routine analysis in order to verify its strength, accuracy and usability. (author)

  19. Determinação de resíduos de pesticidas em plasma bovino por cromatografia gasosa-espectrometria de massas Pesticides residue determination in cattle plasma by gas chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Daniele Fernanda Maffei

    2009-01-01

    Full Text Available An analytical method for the isolation based on matrix solid-phase dispersion technique and gas chromatographic determination of pesticides in cattle plasma is presented. It was fortified 0.25 g of plasma with pesticides and blended with 1 g each C18 and Na2SO4. The homogenized matter was transferred to a SPE cartridge, which contained 1 g of activated florisil with 5 mL acetonitrile. The analites were eluted under vaccum with 15 mL acetonitrile, the extract was analyzed by gas chromatography-mass spectrometry. The limit of quantification of the method was 0.04 mg L-1 for chlorphenvinfos and fipronil and 0.02 mg L-1 for cypermethrin..

  20. Determinação de fósforo em aços por espectrometria de absorção atômica no forno de grafite

    Directory of Open Access Journals (Sweden)

    Curtius Adilson José

    1998-01-01

    Full Text Available A method for the determination of phosphorus in steel samples by graphite furnace atomic absorption spectrometry, using the Zeeman effect background correction and the STPF conditions is proposed. The effect of iron (III on the phosphorus signal was studied. It was verified, through the pyrolysis temperature curves, that iron (III is an efficient chemical modifier, thermically stabilizing phosphorus up to 1400ºC. The phosphorus signal increases with the iron (III concentration, but in the range, which corresponds to the usual concentrations of iron in the sample solutions, the increase is small. Phosphorus was determined in three standard reference materials, after its dissolution in a mixture of hydrochloric and perchloric acids in a PTFE bomb. The agreement with the certified concentration values was excellent. Iron (III was added to the reference analytical solutions prepared in the blank of the dissolution, while the sample solutions were measured directly, since they already contained the modifier. The detection limit (k = 2 was 0.0042% of phosphorus in the steel sample.

  1. Determination of Am-241 in lung and bone by gamma spectrometry with semiconductor detectors LEGe; Determinacion de Am- 241 en pulmon y hueso por espectrometria gamma con detectores de semiconductor LEGe

    Energy Technology Data Exchange (ETDEWEB)

    Perez Lopez, B.

    2014-07-01

    Americium is produced from neutron absorption plutonium atoms within nuclear reactors. The work of dismantling and decontamination of the installations and radioactive waste management makes workers exposed acquire risk of internal exposure and therefore can incorporate Am-241 in his body. (Author)

  2. Experimentos simples usando fotometria de chama para ensino de princípios de espectrometria atômica em cursos de química analítica

    Directory of Open Access Journals (Sweden)

    Okumura Fabiano

    2004-01-01

    Full Text Available The purpose of this paper is the development of simple strategies to teach basic concepts of atomic spectrometry. Metals present in samples found in the daily lives of students are determined by flame atomic emission spectrometry (FAES. FAES is an accurate, precise, and inexpensive analytical method often used for determining sodium, potassium, lithium, and calcium. Historical aspects and their contextualization for students are also presented and experiments with samples that do not require pre-treatment are described.

  3. Aplicação de espectrometria de massas com ionização por elétron na análise de alcaloides do mulungu

    Directory of Open Access Journals (Sweden)

    Luís Guilherme Pereira Feitosa

    2012-01-01

    Full Text Available Erythrina verna is a medicinal plant used to calm agitation popularly known as mulungu. We purchased the barks of E. verna from a commercial producer and analyzed the alkaloid fraction of the bark by CG-MS and HRESI-MS. Five erythrinian alkaloids were identified: erysotrine, erythratidine, erythratidinone, epimer, and 11-hydroxieritratidinone. Here we report the compound 11-hydroxieritratidinone for the first time as a natural product.

  4. X-ray dosimetry in mammography for Mo/Mo combination utilizing Compton spectrometry;Dosimetria de raios X em mamografia para combinacao Mo/Mo utilizando espectrometria Compton

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose Neres de; Terini, Ricardo Andrade, E-mail: rterini@pucsp.b [Pontificia Univ. Catolica de Sao Paulo (PUC-SP), SP (Brazil). Dept. de Fisica; Herdade, Silvio Bruni [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Secao Tecnica de Desenvolvimento em Tecnologia em Saude; Furquim, Tania Aparecida Correia [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Secao Tecnica de Aplicacoes em Diagnostico por Imagem

    2010-08-15

    Objective: to compare mammography benefit and X-ray induced cancer risk, one should investigate absorbed doses. For this purpose, spectra of primary X-ray beams from a clinical mammography equipment were determined for Mo/Mo target/filter combination, using Compton spectrometry and average glandular dose (AGD) in a BR-12 breast phantom was evaluated. Material and Method: a CdTe detector was used for spectrometry of X-ray beams Compton scattered {approx} 100 deg, by a PMMA cylinder, for different depths inside the BR-12 phantom and voltages between 28 and 35 kV. The reconstruction of the primary beam spectra from the measured ones was followed by the determination of AGD. Results: half-value layer values determined by spectra resulted 0.39 to 0.45 mmAl, and by ionization chamber, 0.38 to 0.42 mmAl, respectively, for beams incident on the phantom surface. The AGDN normalized per unitary incident air kerma, on the BR-12 surface, ranged from 0.156 to 0.226. Conclusion: the percentage deviation of AGD{sub N}, relative to the chamber measurements, ranged from 1% to 3%. The utilized method is a good alternative to determine AGD{sub N} and depth-dose distributions in breast phantoms. (author)

  5. Determinação de arsênio em amostras da cadeia produtiva de frangos de corte por espectrometria de absorção atômica com forno de grafite

    Directory of Open Access Journals (Sweden)

    Amália G. G Dionísio

    2011-01-01

    Full Text Available Chicken meat is largely consumed in human nutrition and it is produced in extremely large scale in some countries, including Brazil. In this work graphite furnace atomic absorption spectrometry was used for determination of arsenic in chicken and chicken production-related samples. These samples were digested employing a microwave-assisted procedure in closed vessels using a 7 mol L-1 nitric acid solution plus concentrated hydrogen peroxide. The concentration range of total As determined in chicken production-related samples varied from 1.30 to 29.8 mg kg-1 of As. The detection and quantification limits reached were 0.055 and 0.182 mg kg-1, respectively (n = 15.

  6. Method to analyze spectra and set alerts on environmental gamma spectrometry measurements in real time; Metodo para analizar espectros y establecer alertas tempranas en medidas de espectrometria gamma ambiental en tiempo real

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, E.; Salvado, M.; Casanova, R.

    2013-07-01

    This work describes a method of analysis to extract information radiation from gamma spectra obtained during short time intervals. Therefore, method allows to carry out an analysis of data in real time, which in turn, ensures that an early warning system can be established. (Author)

  7. X-ray dosimetry in mammography for W/Mo and Mo/Mo combinations utilizing Compton spectrometry;Dosimetria de raios X em mamografia para combinacao W/Mo e Mo/Mo utilizando espectrometria Compton

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose N. [Pontificia Univ. Catolica de Sao Paulo (PUC/SP), SP (Brazil). Curso de Fisica; Terini, Ricardo A. [Pontificia Univ. Catolica de Sao Paulo (DF/PUC/SP), SP (Brazil). Dept. de Fisica; Herdade, Silvio B.; Furquim, Tania A.C. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2009-07-01

    Mean Glandular Dose (MGD) cannot be measured directly in mammography equipment. Therefore, methods based on Compton spectrometry are alternatives to evaluate dose distributions in a standard breast phantom, as well as mean glandular dose. In this work, a CdTe detector was used for the spectrometry measurements of radiation scattered by compton effect, at nearly 90, by a PMMA cylinder. For this, the reconstruction of primary beam spectra from the scattered ones has been made using Klein-Nishina theory and Compton formalism, followed by a determination of incident air kerma, absorbed dose values in the breast phantom and, finally, MGD. Incident and attenuated X-ray spectra and depth-dose distributions in a BR-12 phantom have been determined and are presented for the mammography range (28 to 35kV), showing good agreement with previous literature data, obtained with TLD. (author)

  8. Four Brazilian Maytenus salicifolia Reissek (Celastraceae groups studied by TLC and UV/Vis spectrophotometry Estudo de quatro populações de Maytenus salicifolia Reissek (Celastraceae por CCD e espectrometria na região do UV/Vis

    Directory of Open Access Journals (Sweden)

    Frederico N. Valladão

    2009-09-01

    Full Text Available The great variety of angiosperms shows the need to development of botanical classification systems supported by phytochemistry, biochemistry and others. Recently, techniques of analysis used for the isolation and characterization of secondary metabolites have been employed as auxiliary quick and efficient methods for the identification and classification of plant species. M. salicifolia is popularly known in Brazil, as "small coffee" and decoct obtained from its fresh leaves is topically used to alleviate itches and other skins allergic symptoms. This work presents the use of TLC and UV/Vis spectrophotomety processes to be applied like an auxiliary method in botanical taxonomy. The results demonstrate that this process can be used in differentiation of the same genera species, and in the selection of chemical variations between individuals of the same species.A grande variedade de angiospermas apontou a necessidade do desenvolvimento de sistemas de classificação botânica apoiada pela fitoquímica, bioquímica e outras. Recentemente, técnicas de análise utilizadas para o isolamento e caracterização de metabólitos secundários vêm sendo empregadas como métodos auxiliares rápidos e eficientes para identificação e classificação de espécies vegetais. M. salicifolia é popularmente conhecida no Brasil, como "cafezinho". O chá obtido a partir de folhas frescas é usado topicamente para aliviar pruridos e sintomas alergiformes. Este trabalho apresenta a utilização do CCD em sílica gel e espectrofotometria no UV / Vis como métodos auxiliares na identificação botânica de M. salicifolia. Os resultados demonstraram que este processo pode ser usado na diferenciação de plantas do mesmo gênero, assim como detectar variações químicas entre indivíduos de uma mesma espécie.

  9. Spectrometry and emission tomographic image reconstruction stimulated by neutrons via EM algorithm and Monte Carlo Method; Espectrometria e reconstrucao de imagens tomograficas de emissao estimulada por neutrons via algoritmo EM e metodo de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Rodrigo Sartorelo Salemi

    2014-07-01

    The NSECT (Neutron Stimulated Emission Computed Tomography) figures as a new spectrographic technique able to evaluate in vivo the concentration of elements using the inelastic scattering reaction (n,n'). Since its introduction, several improvements have been proposed with the aim of investigating applications for clinical diagnosis and reduction of absorbed dose associated with CT acquisition. In this context, two new diagnostic applications are presented using spectroscopic and tomographic approaches from NSECT. A new methodology has also been proposed to optimize the sinogram sampling that is directly related to the quality of the reconstruction by the irradiation protocol. The studies were developed based on simulations with MCNP5 code. Diagnosis of Renal Cell Carcinoma (RCC) and the detection of breast microcalcifications were evaluated in studies conducted using a human phantom. The obtained results demonstrate the ability of the NSECT technique to detect changes in the composition of the modeled tissues as a function of the development of evaluated pathologies. The proposed method for optimizing sinograms was able to analytically simulate the composition of the irradiated medium allowing the assessment of quality of reconstruction and effective dose in terms of the sampling rate. However, future research must be conducted to quantify the sensitivity of detection according to the selected elements. (author)

  10. Development of an open source software of quantitative analysis for radionuclide determination by gamma-ray spectrometry using semiconductor detectors; Desenvolvimento de um codigo computacional aberto de analise quantitativa para determinacao de radionuclideos por espectrometria gama com detectores semicondutores

    Energy Technology Data Exchange (ETDEWEB)

    Maduar, Marcelo Francis

    2010-07-01

    Radioactivity quantification of gamma-ray emitter radionuclides in samples measured by HPGe gamma-ray spectrometry relies on the analysis of the photopeaks present in the spectra, especially on the accurate determination of their net areas. Such a task is usually performed with the aid of proprietary software tools. This work presents a methodology, algorithm descriptions and an open source application, called OpenGamma, for the peak search and analysis in order to obtain the relevant peaks parameters and radionuclides activities. The computational implementation is released entirely in open-source license for the main code and with the use of open software packages for interface design and mathematical libraries. The procedure for the peak search is performed on a three step approach. Firstly a preliminary search is done by using the second-difference method, consisting in the generation of a derived spectrum in order to find candidate peaks. In the second step, the experimental peaks widths are assessed and well formed and isolated ones are chosen to obtain a FWHM vs. channel relationship, by application of the Levenberg-Marquardt minimization method for non-linear fitting. Lastly, regions of the spectrum with grouped peaks are marked and a non-linear fit is again applied to each region to obtain baseline and photopeaks terms; from these terms, peaks net areas are then assessed. (author)

  11. Espectrometria de absorção atômica: o caminho para determinações multi-elementares Atomic absorption spectrometry: the way for multielement determinations

    Directory of Open Access Journals (Sweden)

    Fábio Alan Carqueija Amorim

    2008-01-01

    Full Text Available This paper present an overview of way covered for the spectrometry of atomic absorption (AAS, tracing a line of the historical events in its development and its establishment as a multielement technique. Additionally, the efforts carried by through several researchers in the search for the instrumental evolution, the advances, advantages, limitations, and trends of this approach are related. Several works focusing its analytical applications are cited employing simultaneous multielement determination by flame (FAAS and/or graphite furnace (GF AAS, and fast sequential multielement determination using FAAS are reported in the present review.

  12. Optimization of the isotopic analysis of UF{sub 6} by quadrupole mass spectrometry technique; Otimizacao da analise isotopica de UF{sub 6} utilizando-se a tecnica de espectrometria de massas por quadrupolo

    Energy Technology Data Exchange (ETDEWEB)

    Porto, Peterson

    2006-07-01

    In the present work a procedure for determination of the isotopic ratio {sup 238}U/{sup 235}U in UF{sub 6} samples was established using a quadrupole mass spectrometer with ionization by electron impact and ion detection by Faraday cup or electron multiplier. For this, the following items were optimized in the spectrometer: the parameters in the ion source that provided the most intense peak, with good shape, for the corresponding mass of the most abundant isotope; the resolution that reduced the non linear effects and the number of analytic cycles that reduced the uncertainty in the results. The measurement process was characterized with respect to the effects of mass discrimination, linearity and memory effect. The mass discrimination showed to be linearly dependent of the sample pressure in the batch volume, for the pressure ranges from 0.15 to 0.30 mbar and from 0.30 to 0.40 mbar. The spectrometer was shown linear in the measurement of isotopic ratios between 0.005 and 0.045. The memory factor for the ion source and for the introduction system were, respectively, 1.000 {+-} 0.001 and 1.003 {+-} 0.003; the first one can be ignored, the second one can be eliminated by washing the batch volume with the new sample. A methodology for routine analysis of UF{sub 6} samples and the determination of the uncertainties were set up in details as well. (author)

  13. Usando um website para explicar a espectrometria de ressonância ciclotrônica de íons por transformada de Fourier Using a website to explain Fourier transform ion ciclotron resonance mass spectrometry

    Directory of Open Access Journals (Sweden)

    Luciano Aparecido Xavier

    2001-06-01

    Full Text Available This article shows the usefulness of a website to explain the concepts, operational events, vacuum system, applications and an experimental sequence of the Fourier Transform Ion Ciclotron Resonance Mass Spectrometry technique (http://143.107.46.113/icr/icrj.html.

  14. Determination of Th and U by neutron activation for gamma spectrometry calibration in situ; Determinacion de Th y U por activacion neutronica para calibracion de espectrometria gamma in situ

    Energy Technology Data Exchange (ETDEWEB)

    Nava M, F.; Rios M, C.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Landsberger, S., E-mail: iqnava@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Pickle Research Campus, R9000 Austin, Texas 78712 (United States)

    2012-10-15

    Using the analysis by neutron activation to determine the profile of the thorium and uranium concentration calibration factors were obtained for their use in the gamma spectrometry in situ. Three sites were selected (San Ramon, Villa de Cos y la Zacatecana) and the analysis by activation was development in the Laboratory of Nuclear Engineering Teaching of the Texas University in Austin with the nuclear reactor Ut-TRIGA. Starting from the gamma spectra in situ, the areas of normalized photo-pick of the radioisotopes were: {sup 208}Tl and {sup 228}Ac for the thorium series and {sup 214}Pb and {sup 214}Bi for the uranium series. The averages of the factors found in units of (cpm/Bq/Kg) are of 105.63{+-}8.32 and 75.87{+-}4.61 for the thorium and uranium, respectively. (Author)

  15. Reassessment of plutonium by alpha spectrometry planchets Aridus-DF-ICP-MS and 1 MV compact AMS; Reevaluacion de plutonio en planchetas de espectrometria alfa mediante ARIDUS-DF-ICP-MS y AMS compacto de 1 MV

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Mendoza, H.; Chamizo Calvo, E.; Yllera de Llano, A.

    2011-07-01

    The aim of this study was to develop and validate, for the first time in Spain, an analytical method for the reevaluation of planchets containing small amounts of 239Pu (between 8 and 40 fg) using two mass spectrometric techniques: mass spectrometry dual approach with inductively coupled plasma source and de solvated Aridus (Aridus-DF-ICP-MS) and accelerator mass spectrometry compact 1 MV (AMS).

  16. Preliminary results of neutron spectroscopy in proton therapy treatment room in Ithemba Labs (South Africa); Resultados preliminares de espectrometria de neutrones en la sala de tratamiento de protonterapia en Ithemba Labs (Sudafrica)

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, C.; Garcia-Fuste, M. J.; Amgarou, K.; Sanchez-Doblado, F.; Nieto-Camero, J.

    2011-07-01

    Proton beams originating from accelerators high energy hadrons lead to the production of neutrons when protons interact with the elements present in the beam line. Furthermore, when these protons are used for proton therapy treatments, their interaction with the patient also involves production of neutrons, mainly due to interactions with the C, O and N. This represents a source of unwanted radiation that increases the risk of developing second cancers by the patient. Assessment of risk factors is one of the goals of our project.

  17. Validation of the alpha spectrometry bio elimination laboratory for measuring activity in excreta; Validacion de la tecnica de espectrometria alfa por el laboratorio de bioeliminacion para la medida de actividad en excretas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Gonzalez, C.; Sierra Bercero, I.; Benito Alonso, P.; Lopez Zarza, C.

    2011-07-01

    the Laboratory Radiation Dosimetry Service of the CIEMAT is undergoing a process of adapting its working methods and quality assurance to management and technical requirements established in ISO / IEC 17025:2005 with to obtain accreditation shortly ENAC.

  18. Compton spectrometry applied to dose measurement in mammography for W/Mo and Mo/Mo combinations; Espectrometria Compton aplicada a medicao de doses em mamografia para combinacoes W/Mo e Mo/Mo

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Junior, Jose N. [Pontificia Univ. Catolica de Sao Paulo (PUC/SP), SP (Brazil); Terini, Ricardo A., E-mail: rterini@pucusp.b [Pontificia Univ. Catolica de Sao Paulo (PUC/SP), SP (Brazil). Dept. de Fisica; Herdade, Silvio B.; Furquim, Tania A.C. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2010-06-15

    Mean Glandular Dose (MGD) cannot be measured directly in mammography equipment. Therefore, methods based on Compton spectrometry are alternatives to evaluate dose distributions in a standard breast phantom, as well as mean glandular dose. In this work, a CdTe detector was used for the spectrometry measurements of radiation scattered by Compton Effect, at nearly 90 deg, by a PMMA cylinder inserted between the breast phantom plates. For this, the reconstruction of primary beam spectra from the scattered ones has been made using Klein-Nishina theory and Compton formalism, followed by a determination of incident air kerma, absorbed dose values in the breast phantom and, finally, MGD. Incident and attenuated X-ray spectra and depth-dose distributions in a BR-12 phantom have been determined and are presented for the mammography range (28 to 35kV). Results have shown good agreement with previous literature data, obtained with TLD. (author)

  19. A espectrometria atômica e a determinação de elementos metálicos em material polimérico Atomic spectrometry and the determination of metals in polymeric materials

    Directory of Open Access Journals (Sweden)

    Solange Cadore

    2008-01-01

    Full Text Available Polymeric materials are widely used in the chemical industry and are part of our daily lives. Inorganic species may be added to them as additives, anti-oxidizing agents, stabilizers, plasticizers, colorants and catalysts and may be present in a wide range of concentrations. Their determination demands the development of analytical methods considering different kinds of polymeric materials, their composition and the final use of the material. Although many different analytical techniques may be used, this review emphasizes those based on atomic absorption and emission spectrometry. Solid sampling techniques and digestion methods are described and discussed and compared considering published results.

  20. Espectrometria de massas com ionização por "electrospray": processos químicos envolvidos na formação de íons de substâncias orgânicas de baixo peso molecular

    Directory of Open Access Journals (Sweden)

    Crotti Antônio Eduardo Miller

    2006-01-01

    Full Text Available An overview of the current literature on the chemical processes involved in the ion formation from low molecular weight organic compounds by electrospray ionization mass spectrometry is given.

  1. Avaliação da composição mineral do chá da folha senescente de Montrichardia linifera (arruda schott (araceae por espectrometria de absorção atômica com chama (FAAS

    Directory of Open Access Journals (Sweden)

    Cristine Bastos do Amarante

    2011-01-01

    Full Text Available Levels of Ca, Mg, Fe, Zn, Cu and Mn were determinated by FAAS in the tea and dry matter from senescent leaf from Montrichardia linifera, plant used in folk medicine Amazon. The content of these metals that are transferred of the leaf to the infusions have presented significant reductions, however, the Mn values in the infusion may exceed the tolerable daily intake (11 mg if consumption of this tea is greater than 1.0 L per day. So the tea of senescent leaves of M. linifera may be considered as a toxic beverage and thus its use is not advised.

  2. Paint samples preparation methods for metals and methaloids determination by atomic spectrometry techniques; Estudo comparativo de metodos de preparo de amostras de tinta para a determinacao de metais e metaloides por tecnicas de espectrometria atomica

    Energy Technology Data Exchange (ETDEWEB)

    Bentlin, Fabrina R.S.; Pozebon, Dirce; Depoi, Fernanda dos Santos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica], e-mail: dircepoz@iq.ufrgs.br

    2009-07-01

    This work deals with paint decomposition methods for major, minor and trace elements determination. Three methods were investigated: (1) decomposition in closed quartz vessel and heating in microwave oven; (2)decomposition in open vessel using HNO{sub 3} and ashing, following the ASTM D 3335-85a method; and (3) decomposition in open vessel using HNO{sub 3} + HF and ashing. Paints of different types and colours were analyzed, in which several elements were determined using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP OES). It was observed that method (1) is appropriate for trace, minor and major elements determination, while method (3) is appropriate for Ti. (author)

  3. Determination of essential and toxic elements in commercial baby foods by instrumental neutron activation analysis and atomic absorption spectrometry; Determinacao dos elementos essenciais e toxicos em alimentos comerciais infantis por analise por ativacao com neutrons e espectrometria de absorcao atomica

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila

    2013-08-01

    The World Health Organization recommends that infants should be breast fed exclusively for at least six months after birth. After this period, it is recommended to start introducing complementary foods, in order to meet the child's nutritional, mineral and energy needs. Commercial food products for infants form an important part of the diet for many babies. Thus, it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of infant malnutrition in developing countries. In this study, essential elements: Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Se and Zn and toxic elements: As, Cd, Hg levels were determined in twenty seven different commercial infant food product samples by Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (AAS). In order to validate both methodologies the reference material: INCT MPH-2 Mixed Polish Herbs and NIST - SRM 1577b Bovine Liver by INAA and NIST - SRM 1548th Typical Diet and NIST - SRM 1547 Peach Leaves by AAS were analyzed. The twenty seven baby food samples were acquired from Sao Paulo city supermarkets and stores. Essential and toxic elements were determined. Most of the essential element concentrations obtained were lower than the World Health Organization requirements, while concentrations of toxic elements were below the tolerable upper limit. These low essential element concentrations in these samples indicate that infants should not be fed only with commercial complementary foods. (author)

  4. Determinações multi-elementares de metais, Sulfato e Cloreto em amostras de águas por espectrometria de massas com fonte de plasma (ICP-MS

    Directory of Open Access Journals (Sweden)

    Menegário A. A.

    1998-01-01

    Full Text Available The multi-element determination of Al, Cr, Mn, Ni, Cu, Zn, Cd, Ba, Pb, SO4= and Cl- in riverine water samples was accomplished by inductively coupled plasma mass spectrometry (ICP-MS. The sample passed through a column containing the anionic resin AG1-X8 and the metals were determined directly. The retained anionic species were eluted and SO4= and Cl- were determined at m/z 48 and 35 correspondent to the ions SO+ and Cl+ formed at the plasma. Accuracy for metals was assessed by analysing the certified reference TM-26 (National Water Research Institute of Canada. Results for SO4= and Cl- were in agreement with those obtained by turbidimetry and spectrophotometry. LOD's of 0.1 µg l-1 for Cd, Ba and Pb; 0.2 µg l-1 for Al, Mn and Cu; 0.5 µg l-1 for Cr; 0.9 for Zn; 2.0 µg l-1for Ni , 60 µg l-1 for S and 200 µg l-1 Cl were attained.

  5. DETERMINAÇÃO DE METAIS POR TÉCNICAS DE ESPECTROMETRIA ATÔMICA EM AMOSTRAS DE CARVÃO MINERAL E CINZAS UTILIZANDO METODOLOGIA DE SUPERFÍCIE DE RESPOSTA

    Directory of Open Access Journals (Sweden)

    Camila M. Oliz

    Full Text Available This paper describes the method optimization using response surface methodology for Cu, Fe, Zn and Na determinations in coal and ash samples by spectrometry techniques. The sample preparation was performed using a recirculation system adapted in the digestion tubes. This system allowed increase of temperature in the digester block above the boiling point of the reaction medium, avoiding acid evaporation during the heating. The digestions were realized with HNO3 and H2O2 for 1 h in a digester block at 145 °C. The limits of detection for determination of Cu, Fe, Zn and Na in both samples were satisfactory. The RSD for the analytes were lower than 6.0%. Statistical tests showed that results for all analytes do not vary significantly with official method (ASTM, considering a confidence limit of 95%. Besides, the accuracy was verified by recovery tests, whose values ranged from 92.7 to 104.7% in coal, and 98.7 to 115.3% in ash.

  6. Methodology for measuring surfaces using in situ gamma spectrometry in nuclear and radiological emergencies; Metodologia de medida de superficies mediante espectrometria gamma in sit en emergencias radiologicas y nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Yague, L.; Navarro, N.; Perez, C.; Perez-Cejuela, P.; Vico, A.; Maquez, J. L.; Alvarez, A.

    2013-07-01

    CIEMAT has an environmental mobile unit for measurements of ambient dose rate and activity concentration in air. In addition, recently it included the ability to surface concentration measurement. This measure is particularly useful for making decisions about emergency decontaminate surfaces according to the criteria of the DBRR. (Author)

  7. Spatial resolution in laser ablation inductively coupled plasma mass spectrometry; Resolucion espacial en la ablacion laser acoplada a la espectrometria de masas con fuente de plasm de acoplamiento inductivo

    Energy Technology Data Exchange (ETDEWEB)

    Coedo, A. G.; Dorado, M. T.

    2010-07-01

    Laser ablation as sampling system in inductively coupled plasma mass spectrometry (LA-ICP-MS) offers the possibility to know the spatial distribution of elements present in a solid sample. By varying the position of the laser beam on the sample surface, the profile of the lateral distribution of elements is obtained and, with successive pulses fired on a fixed point, profile in depth is achieved. After optimization of operating parameters the technique has been applied to samples with different compositions in both surface and depth.With regard to the lateral resolution has been found that in a length similar to the crater diameter of the laser beam, the signals of the elements appear mixed, making difficult to accurately establish the interface. Regarding the resolution in depth is clearly established the influence of the natural abundance of the measured isotopes. (Author)

  8. Software tool for resolution of inverse problems using artificial intelligence techniques: an application in neutron spectrometry; Herramienta en software para resolucion de problemas inversos mediante tecnicas de inteligencia artificial: una aplicacion en espectrometria neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda M, V. H.; Martinez B, M. R.; Solis S, L. O.; Castaneda M, R.; Leon P, A. A.; Hernandez P, C. F.; Espinoza G, J. G.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, 98000 Zacatecas, Zac. (Mexico); Mendez, R. [CIEMAT, Departamento de Metrologia de Radiaciones Ionizantes, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Sousa L, M. A. [Comision Nacional de Energia Nuclear, Centro de Investigacion de Tecnologia Nuclear, Av. Pte. Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The Taguchi methodology has proved to be highly efficient to solve inverse problems, in which the values of some parameters of the model must be obtained from the observed data. There are intrinsic mathematical characteristics that make a problem known as inverse. Inverse problems appear in many branches of science, engineering and mathematics. To solve this type of problem, researches have used different techniques. Recently, the use of techniques based on Artificial Intelligence technology is being explored by researches. This paper presents the use of a software tool based on artificial neural networks of generalized regression in the solution of inverse problems with application in high energy physics, specifically in the solution of the problem of neutron spectrometry. To solve this problem we use a software tool developed in the Mat Lab programming environment, which employs a friendly user interface, intuitive and easy to use for the user. This computational tool solves the inverse problem involved in the reconstruction of the neutron spectrum based on measurements made with a Bonner spheres spectrometric system. Introducing this information, the neural network is able to reconstruct the neutron spectrum with high performance and generalization capability. The tool allows that the end user does not require great training or technical knowledge in development and/or use of software, so it facilitates the use of the program for the resolution of inverse problems that are in several areas of knowledge. The techniques of Artificial Intelligence present singular veracity to solve inverse problems, given the characteristics of artificial neural networks and their network topology, therefore, the tool developed has been very useful, since the results generated by the Artificial Neural Network require few time in comparison to other techniques and are correct results comparing them with the actual data of the experiment. (Author)

  9. Determination of Cd and Pb in canned pineapple by atomic absorption spectroscopy using a graphite oven; Determinacion de Cd y Pb en pina enlatada por espectrometria de absorcion atomica utilizando horno de grafito

    Energy Technology Data Exchange (ETDEWEB)

    Linares P, G.; Sanchez P, L.; Benavides M, A.; Acosta L, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Owing to the food susceptibility to be contaminated it is necessary to realize pursuit studies or frequent monitoring about the content of certain metals which represent health risks by its toxicological effects in the human being and another living organisms. In this work the cadmium and lead concentrations are determined in six national brands of canned pineapple analysing separately sugar sirup and the fruit. (Author)

  10. Aplicação da química quântica computacional no estudo de processos químicos envolvidos em espectrometria de massas Application of computational quantum chemistry to chemical processes involved in mass spectrometry

    Directory of Open Access Journals (Sweden)

    Ricardo Vessecchi

    2008-01-01

    Full Text Available The field of application of mass spectrometry (MS has increased considerably due to the development of ionization techniques. Other factors that have stimulated the use of MS are the tandem mass spectrometry (MS/MS and sequential mass spectrometry (MSn techniques. However, the interpretation of the MS/MS and MSn data may lead to speculative conclusions. Thus, various quantum chemical methods have been applied for obtaining high quality thermochemical data in gas phase. In this review, we show some applications of computational quantum chemistry to understand the formation and fragmentation of gaseous ions of organic compounds in a MS analysis.

  11. Xanthium strumarium L. antimicrobial activity and carboxyatractyloside analysis through electrospray ionization mass spectrometry Atividade antimicrobiana e análise de carboxiatractilosideo por espectrometria de massas com ionização por electrospray de Xanthium strumarium L

    Directory of Open Access Journals (Sweden)

    R. Scherer

    2009-01-01

    Full Text Available The aim of this work was to evaluate the antimicrobial activity of Xanthium strumarium L. leaf extracts against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Clostridium perfringens, as well as to investigate the presence of the toxic compound carboxyatractyloside in different plant parts. S. aureus and C. perfringens were more sensitive to non-polar than to polar fractions, and there was no difference between extracts for the remaining bacteria. All extracts had strong antimicrobial activity against the evaluated microorganisms. Carboxyatractyloside was found in cotyledons and seeds but not in adult leaves and burrs. Thus, only Xanthium strumarium leaves in adult stage can be used for medicinal purposes.O objetivo do presente trabalho foi avaliar a atividade antimicrobiana de extratos de folhas de Xanthium strumarium L. sobre os microrganismos Staphylococcus aureus, Escherichia coli, Salmonella thyphimurium, Pseudomonas aeruginosa e Clostridium perfringens, bem como verificar a presença do composto tóxico carboxiatractilosideo em diferentes partes da planta. As bactérias S. aureus e C. perfringens foram mais sensíveis às frações não polares do que as polares, sendo que para as outras bactérias não foi verificada diferença entre os extratos. Todos os extratos apresentaram uma forte ação antimicrobiana sobre os microrganismos avaliados. O carboxiatractilosideo foi encontrado nos cotilédones e nas sementes da planta, entretanto, não foi encontrado nas folhas em estádio adulto e na carapaça espinhosa que envolve a semente. Portanto, somente as folhas de Xanthium strumarium na fase adulta podem ser utilizadas para o uso medicinal.

  12. Optimization of the architecture of a neural network in neutron spectrometry to reduce the number of Bonner spheres; Optimizacion de la arquitectura de una red neuronal en espectrometria de neutrones para reducer el numero de esferas Bonner

    Energy Technology Data Exchange (ETDEWEB)

    Leon P, A. A.; Martinez B, M. R.; Hernandez P, C. F.; Espinoza G, J. G.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, ETSI Industriales, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); De Sousa L, M. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The neutron spectrometry is an experimental process for determining the energy distribution called the Spectrum. Among the methods available for neutron spectrometry, one can mention the Bonner Sphere Spectrometric System as one of the most used, consisting of a detector placed in the center of a set of polyethylene spheres whose diameters range from 2 to 18 inches, however has some disadvantages such as the long periods of time to perform the measurements, the weight and the spheres number that vary according to the system. From this, alternative methods such as artificial neural networks are proposed. For this project neural networks of reverse propagation were used with the methodology of robust design of artificial neural networks, with the aid of a computational tool that maximizes the performance, making the time used for the training s of the network is the smallest possible and thus gets the orthogonal fixes quickly to determine the best network topology. The counting rates of a spectrometric system with 7 spheres, 2 spheres and one sphere of 5 and 8 inches were used. This methodology seeks to reduce the work used as in the spectrometric system formed by a greater number of spheres, since to enter less data in the counting rates to obtain the spectra with 60 energy levels saves time and space, because at having a smaller number of spheres its portability is easier to move from one place to another, for this we performed several experiments with different errors until we reached the optimal error so that the topology of the network was appropriate and find the best design parameters. A statistical software JMP was also used to obtain the best topologies and thus to retrain obtaining its best and worst spectra, in order to determine if the reduction is possible. (Author)

  13. Simultaneous determination of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry INa(Ti), in solid samples.; Determinacion de U (Natural), Th (Natural) y Ra-226 en diversos materiales, mediante espectrometria con INa (TI)

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, S.; Navarro, T.; Alvarez, A.

    1991-07-01

    A method has been developed to determine activities of Ra-226, natural uranium and natural thorium by gamma-ray spectrometry. The measurement system has been calibrated using standards specially prepared at the laboratory. It is necessary to assume secular equilibrium in the samples, between Ra-226 and Th-232 and its daughters nuclides, and between U-238 and its immediate daughter Th-234, as the photo peaks measured are those of the daughters. The results obtained indicate that this method can of ter replace the radiochemical techniques used to measure activities in this type of sample. The method has been successfully used to determine these natural isotopes in samples from uranium mills. (Author) 9 refs.

  14. Quantification of {sup 235} U and {sup 226} Ra in soil samples by means of Gamma spectroscopy; Cuantificacion de {sup 235} U y {sup 226} Ra en muestras de suelo por medio de espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Quintero P, E.; Rojas M, V.P.; Montes M, F.R.; Gaso P, M.I.; Cervantes N, M.L. [Gerencia de Innovacion Tecnologica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    In this work it is presented the Gamma Spectroscopy method which is realized in the Environmental Radiological Surveillance Laboratory using the option of deconvolution of a commercial software for the quantification of {sup 235} U and {sup 226} Ra; also is presented the method for the {sup 226} Ra correction activity. (Author)

  15. Determination of rubidium and strontium in geological materials by X-Ray fluorescence spectrometry; Determinacion de rubidio y estroncio en materiales geologicos mediante espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.

    1979-07-01

    In order to determine whole-rock ages by the Rb/Sr procedure, an X-ray fluorescence spectrometry method for the determination of both elements has been developed. The samples are pressed into boric acid backed and ringed pellets with this material as a binding agent. Matrix corrections are made following the determination od the mass absorption coefficients, based on the intensity of the Compton-scattered peak of MoK{alpha}. or MoK{beta}{sub 1}.3. The U. S. Geological Survey granodiorite GSP-1 is used as a reference standard. Spectral-line interferences have been carefully studied and the empirical correction factors determined. A BASIC language program for calculating the Rb and Sr concentrations and the Rb/Sr ratios has been written. (Author) 7 refs.

  16. Development and calibration automatic equipment's measuring in real time of the environmental radioactivity by gamma spectrometry; Desarrollo y calibracion de equipos automaticos de medida en tiempo real de la radiactividad ambiental mediante espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Casanovas, R.; Morant, J. J.; Salvado, M.

    2013-07-01

    In this paper, we describe the general aspects of the implementation of gamma spectrometry in water, as well as the development of two measuring devices based on this technique: aerosol monitor (RARM-F) and a monitor direct measurement (RARMD2) , both patent applications. Furthermore, they described in detail the aspects of calibration of equipment, which has been made by combining experimental measurements with Monte Carlo simulations. (Author)

  17. Design of a computation tool for neutron spectrometry and dosimetry through evolutionary neural networks; Diseno de una herramienta de computo para la espectrometria y dosimetria de neutrones por medio de redes neuronales evolutivas

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico); Martinez B, M. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, Jose Gutierrez Abascal No. 2, E-28006 Madrid (Spain)], e-mail: morvymmyahoo@com.mx

    2009-10-15

    The neutron dosimetry is one of the most complicated tasks of radiation protection, due to it is a complex technique and highly dependent of neutron energy. One of the first devices used to perform neutron spectrometry is the system known as spectrometric system of Bonner spheres, that continuous being one of spectrometers most commonly used. This system has disadvantages such as: the components weight, the low resolution of spectrum, long and drawn out procedure for the spectra reconstruction, which require an expert user in system management, the need of use a reconstruction code as BUNKIE, SAND, etc., which are based on an iterative reconstruction algorithm and whose greatest inconvenience is that for the spectrum reconstruction, are needed to provide to system and initial spectrum as close as possible to the desired spectrum get. Consequently, researchers have mentioned the need to developed alternative measurement techniques to improve existing monitoring systems for workers. Among these alternative techniques have been reported several reconstruction procedures based on artificial intelligence techniques such as genetic algorithms, artificial neural networks and hybrid systems of evolutionary artificial neural networks using genetic algorithms. However, the use of these techniques in the nuclear science area is not free of problems, so it has been suggested that more research is conducted in such a way as to solve these disadvantages. Because they are emerging technologies, there are no tools for the results analysis, so in this paper we present first the design of a computation tool that allow to analyze the neutron spectra and equivalent doses, obtained through the hybrid technology of neural networks and genetic algorithms. This tool provides an user graphical environment, friendly, intuitive and easy of operate. The speed of program operation is high, executing the analysis in a few seconds, so it may storage and or print the obtained information for further analysis and treatment. (Author)

  18. Aspectos moleculares da fração acida de querosene de aviação : sintese de padrões (fenolicos, acidos carboxilicos e neutros) para analise em cromatografia gasosa acoplada a espectrometria de massas

    OpenAIRE

    Joana D'Arc Felix de Sousa

    1990-01-01

    Resumo: O petróleo Cabiúnas, proveniente da Bacia de Campos, possui um índice de acidez considerável (IA = 1,0), classificando-o como petróleo de acidez média para alta. Sabemos que as frações do petróleo, Querosene de Aviação (QAV) e Gasolina, são obtidas numa faixa de ebulição (250-300°C) semelhante à faixa de destilação dos ácidos naftênicos (200-370°C). Este fato nos motivou a estudar a fração ácida do Querosene de Aviação em uma confirmação de resultados anteriores, deste laboratório. A ...

  19. Determination of activity by gamma spectrometry of radionuclides present in drums of residues generated in nuclear centrals; Determinacion de actividad por espectrometria gamma de radionucleidos presentes en tambores de residuos generados en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, J.C.; Fernandez, J. [Autoridad Regulatoria Nuclear, Av. Del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina)]. e-mail: jaguiar@cae.arn.gov.ar

    2006-07-01

    The generation of radioactive residuals in nuclear centrals as CNA I (Atucha I Nuclear Central) and CNE (Embalse Nuclear Central) makes that the measurement of those radionuclides has been a previous stage to the waste management. A method used in those nuclear centrals it is the gamma spectrometry with HPGe detectors, previous to the immobilization of the residual in a cemented matrix, with this the contact with the external agents and its possible dispersion to the atmosphere in the short term is avoided. The ARN (Nuclear Regulatory Authority) of Argentina it carries out periodically intercomparisons and evaluations of the measurement and procedures systems used in the nuclear power stations for the correct measurement and determination of activity of radioactive residuals by gamma spectrometry. In this work an independent method of measurement is exposed to the nuclear power stations. To determine the activity of the residuals by gamma spectrometry deposited in drums, it is required of the precise knowledge of the efficiency curve for such geometry and matrix. Due to the RNA doesn't have a pattern of these characteristics, a mathematical model has been used to obtain this efficiency curve. For it, it is necessary to determine previously: 1) the geometric efficiency or solid angle sustained by the source-detector system (drum-detector) applying a mathematical model described in this work. 2) To estimate the auto-attenuation factor that present the photons in the cemented matrix, these calculations are carried out with a simple equation and its are verified with the Micro Shield 6.10 program. The container commonly used by these nuclear power stations its are drums for 220 liters constructed with SAE 1010 steel and with a thickness of 0.127 cm, with an approximate weight 7.73 Kg., internal diameter of 57.1 cm, and height: 87 cm. The results obtained until the moment register a discrepancy from 5 to 10% with relationship to the measurements carried out by the nuclear power stations. (Author)

  20. Study on the natural radioactivity from the region of Presidente Figueiredo (AM), Brazil, using gamma spectrometry; Estudo da radioatividade natural da regiao de Presidente Figueiredo (AM) utilizando espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Jose Ribamar Silveira

    1999-07-01

    A gamma spectrometry profile was carried out along BR174 highway, that crosses some lithostratigraphic units of the North portion of the Sedimentary Basin of Amazon. Measurements in situ were realized in 116 points, 1 km apart, using a GAD-6 gamma-spectrometer and samples of rocks and soils were collected in geologically representative points, for gamma measurements using a shielded detector of NaI(Tl) available in the Nuclear Geophysics Laboratory of IAG/USP. The criterion used for evaluating the reliability degree of the concentration values of eU (ppm), eTh (ppm) and %K was to establish mathematically detection limits, for all measurement points. Every these points had been located using GPS with accuracy of 50 m to become possible a future detailed study. The purpose of matching portable gamma spectrometer and laboratory determinations was to compare the 2 techniques, using the criterion of detectability limits, and to verify the influence of {sup 222} Rn atmospheric radioactive gas in field measurements. In the case of portable detector, it allows fast measurements and the sensor 'sees' a big volume of material (rock, soil...), that makes it more representative. In some situations where atmospheric phenomena of thermal inversion occurs, measurement can be affected by the {sup 222} Rn cosmic background. Presence of radon daughter elements, associated with aerosols, in this tropical environment (high values of temperature and humidity), where the speed of the wind that could exhaust this gas is practically zero. It is observed that the values of concentration in the some points, got with these 2 techniques, have the same trend, and the stretches where peaks of concentration of K also occur and U and Th are associated with the presence of granite out corps, great boulders, and clay soils from weathering of these rocks. (author)

  1. {sup 34}S determination by using mass spectrometry (% in atoms) of s-sulfate available in soil samples; Determinacao de {sup 34} S por espectrometria de massas (% em atomos), do s-sulfato disponivel em amostras de solo

    Energy Technology Data Exchange (ETDEWEB)

    Rossete, Alessandra L.R.M.; Bendassolli, Jose A.; Trivelin, Paulo C.O.; Bicudo, Milena; Duarte, Debora C.S.; Teixeira, Gleuber M. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis

    2002-07-01

    S{sup 34} determination in soil samples is used in agronomic investigations, involving the use of {sup 34} S tracer in sulfur cycle studies. The tests were accomplished with clay soil in two treatments: T1: fertilized with 48.78 mg S kg{sup -1} and abundance of 9.12 atom % {sup 34}S, and T2: control, without S fertilization. The experiment was carried out in pots with 7 kg of soil. The test plant was the soybean. The extraction of residual SO{sub 4}{sup -2} using Ca(H{sub 2}PO{sub 4}){sub 2} solution as extractor was done in soil samples from the treatments T1 and T2, after the harvesting of soybean plants. The extract was filtered and the S-SO{sub 4}{sup -2} concentration was determined by turbidimetric method. After extraction, SO{sub 4}{sup -2} was precipitated in the BaSO{sub 4} form by adding to the solution BaCl{sub 2}.H{sub 2}O. Finally, SO{sub 2} was obtained on high line vacuous, in V{sub 2}O{sub 5} and SiO{sub 2} presence, at 900 deg C temperature. {sup 34}S determination (atom %) in the SO{sub 2} was carried out at the mass spectrometer ATLAS-MAT model CH4. The average of concentrations of S-SO{sub 4} available in T1 and T2 were 37.3{+-}1.7 and 15.6{+-}2.0 mg kg{sup -1}, respectively. {sup 34} S abundance were 6.04{+-}0.25 and 4.56{+-}0.02 atom %, respectively, for the treatments T1 and T2. (author)

  2. protVirt: simulação da dosagem de proteínas por espectrometria auxiliando as aulas práticas de Bioquímica

    OpenAIRE

    Gabriel Gerber Hornink

    2016-01-01

    The practical classes in the teaching of biochemistry could provide great contributions to the process of teaching and learning, and the understanding of these by students depend on, generally,  previous concepts about the experiment and procedures performed. It is presented in this paper the educational software protVirt, which could be used as a pedagogical innovation in the method of practical classes involving dosage of proteins, focusing on the development of skills for understanding the...

  3. Análise de pesticidas organoclorados em água usando a microextração em fase sólida por headspace com cromatografia gasosa e espectrometria de massas

    Directory of Open Access Journals (Sweden)

    Crislaine Batista Prates

    2011-01-01

    Full Text Available A method based on headspace - solid phase microextraction coupled with gas chromatography - mass spectrometry was validated for the quantitative determination of 18 organochlorine pesticides in water. For the extraction conditioning some parameters as the best type of coating fiber, time and temperature of extraction, pH and ionic strength were evaluated. The method HS-SPME/GC-MS/MS showed linear coefficient above 0.9948. The repeatability of the measurements were lower than 7.6%. Relative recoveries were between 88 and 110%. Limits of detection from 0.5 x 10-3 to 1.0 mg L-1 were obtained. A total of 31 samples were analyzed and 16 presented from 1 to 5 pesticides.

  4. An X-ray fluorescence method for the determination of small quantities el elements collected on filters; Determinacion de pequenas concentraciones de elementos en filtros por espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.; Bayon, A.

    1981-07-01

    An X-ray fluorescence method for the determination of As, Ba, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, U, V and Zn collected on P.V.C. filters in concentration ranges from 0,6 to 1000{mu}g, depending on the element, is described. A sequential automatic spectrometer with a chromium tube is used for tho Ba determination, while As, Hg, Pb, Se and U are bottler determined with a molybdenum one. For the rest of the elements a tungsten target is preferred. The interferences between AsK{sup {alpha}}{sub 1},2- PbL{sup {alpha}}{sub 1},2 and CrK{sup {alpha}}{sub 1},2-Vk{beta}{sub 1},3 lines are corrected by applying specific coefficients. The radial variation of the primary X-ray beam intensity on the irradiated surface has been specially studied with chromium, gold, molybdenum and tungsten tubes. For that purpose different x-ray wavelengths in the range 9,89 A to 0,56 A have been selected. The curves obtained show a rather high heterogeneity for the excitation source. This conclusion implies the need for an homogeneous distribution of elements on the filter. (Author) 7 refs.

  5. Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS); Avaliacao da combinacao da nebulizacao discreta e processos de microextracao aplicados a determinacao de molibdenio por espectrometria de absorcao atomica com chama (FAAS)

    Energy Technology Data Exchange (ETDEWEB)

    Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R., E-mail: erpf@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

    2014-04-15

    Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L{sup -1} were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

  6. Determination and quantification of impurities found in samples of {sup 124}I using gamma spectrometry; Determinacao e quantificacao de impurezas encontradas em amostra de {sup 124}I usando a espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ronaldo Lins da; Delgado, Jose Ubiratan; Araujo, Miriam Taina Ferreira de; Laranjeira, Adilson da Silva; Poledna, Roberto; Veras, Eduardo de; Almeida, Maria Candida M. [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Braghirolli, Ana Maria S. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    {sup 124}I, positron emitter is produced in the IEN/CNEN-RJ and used in diagnosis image of tumors. In this radioisotope production process impurities appear and health agency requires that the level of these characteristics is quantified. These radionuclides emit gamma and X-radiation, allowing the identification and quantitation by gamma spectrometry. With the use of HPGE detector, coupled with the efficiency curve, was identified {sup 125}I and {sup 126}I. The impurity levels measured in the sample were in the range of 0.5% to 90%, respectively, indicating the feasibility of the method for controlling the quality of the radiopharmaceutical.

  7. Absolute standardization of {sup 121}Te by gamma spectrometry using the peak-sum method; Padronizacao absoluta do {sup 121}Te por espectrometria gama utilizando o metodo pico-soma

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Miriam Taina Ferreira de

    2015-06-01

    This work has as main objective to develop a methodology for identification and quantification of impurities in the production process of the radiopharmaceutical [{sup 123}I]Nal. As a specific goal we mention the process of absolute standardization of {sup 121}Te. The determination of some nuclear parameters associated with the decay is the step of secondary endpoints where data obtained will be compared with the existing literature.

  8. X-ray fluorescence spectrometry used to assess the dispersion of metals within mining environments; Aplicacion de la tecnica de espectrometria de fluorescencia de rayos-X en el estudio de la dispersion de metales en areas mineras

    Energy Technology Data Exchange (ETDEWEB)

    Margui, E.; Gonzalez-Fernandez, O.; Hidalgo, M.; Pardini, G.; Queralt, I.

    2011-07-01

    One critical factor for success in characterizing metals polluting mining environments so as to be able to eliminate them and subsequently recover these areas depends upon a speedy and correct response in the analysis of samples. Rapid, simultaneous, multi-element analysis can be undertaken using X-ray fluorescence spectrometry, a versatile, non-destructive analytical technique commonly employed to identify both major and minor elements in samples related to environmental studies. An additional advantage of this technique is the possibility of conducting the analysis directly on solid samples, which is extremely convenient when dealing with environmental samples that are difficult to dissolve, such as soils, sediments and mining wastes. Moreover, in recent years the development of spectrometers equipped with digital-signal processors combined with enlarged X-ray production, using better designs for excitation-detection, has contributed to an improvement in instrumental sensitivity, thus allowing us to detect important polluting elements such as Cd and Pb at trace levels. In this paper the authors describe, on the basis of their own experience, some interesting applications of XRF spectrometry for the analysis of several types of environmental samples related to the study of the dispersion of metals within mining environments: (A) analysis of mining wastes, soils and sediments; (B) analysis of samples of vegetation used as bio indicators or related to phyto remediation studies; and (C) analysis of water samples related to mining operations. (Author) 26 refs.

  9. Aplicação de espectrometria de massa no controle de qualidade de inoculantes comerciais agrícolas contendo bactérias promotoras de crescimento vegetal

    OpenAIRE

    Silva,Leilane Caline

    2014-01-01

    Orientador : Prof. Dr. Leonardo Magalhães Cruz Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ciências : Bioquímica. Defesa: Curitiba, 28/02/2014 Inclui referências : f. 70-79 Resumo: As rizobacterias promotoras do crescimento vegetal (PGPR) sao bactérias do solo benéficas para o crescimento de plantas e para a agricultura pois podem influenciar positivamente no rendimento da safra. Bactérias do gênero Azospirillum ...

  10. Determination of {sup 226}Ra by gamma spectrometry: study of packaging vial of sample for analysis; Determinacao de {sup 226}Ra por espectrometria gama: estudo do recipiente de acondicionamento de amostra para analise

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti

    2015-07-01

    Determination of radioactivity levels of {sup 226}Ra by gamma spectrometry in a sample is based on measurements of {sup 214}Pb and {sup 214}Bi, daughters of {sup 222}Rn. Because radon is a gas, it can leak from the sample vial or accumulate on the upper empty it. If the vial has any crack, there will be loss of gas, which will cause error in determining the {sup 226}Ra concentration. One possible cause of cracks in the vials, that houses standards and samples, is the radiolysis action in the vial material, usually a polymer. As the demand {sup 226}Ra analysis in different matrices (geological samples, food, plants, etc.) is increasing, it was decided to study some polymer vials available on the market, to verify the feasibility to be used when is applied the analysis method using gamma spectrometry. Four types of polymer vials have been studied. The radiation doses in walls of the vials caused by natural radionuclides present in the sample were simulated using gamma irradiation. Tests, such as compressive strength test and tightness, were applied to the irradiated and non-irradiated vials. First, to verify the effect of radiolysis on the vial material and also if there was {sup 222}Rn diffusion in their walls. These preliminary results pointed out that the acrylic vials are the best option of packaging samples for analysis. This study should be repeated in a larger number of samples for a better evaluation. (author)

  11. Determinação de bifenilos policlorados em milho através de extração em fase sólida seguida de cromatografia a gás acoplada à espectrometria de massas

    Directory of Open Access Journals (Sweden)

    Thiago Guilherme Schwanz

    2012-01-01

    Full Text Available This paper describes an analytical method for analyzing polychlorinated biphenyls in corn samples using solid phase extraction (SPE followed by determination by GC-MS. All calibration curves proved linear (r> 0.99. Recoveries ranged between 74.1 and 110.6% with relative standard deviation lower than 20% for all compounds. The limits of quantitation for the method were between 0.025 and 0.1 ng g-1. Of the 51 samples analyzed, PCB 180 showed the highest frequency, being detected in more than 39%, followed by PCB 138, detected in more than 33% of samples.

  12. Gamma-ray Spectrometry Of Granite Pegmatite Pegmatitic Province Borborema (ppb), Northeast Brazil [espectrometria De Raios Gama De Granitos Pegmatíticos Da Província Pegmatítica Da Borborema (ppb), Nordeste Do Brasil

    OpenAIRE

    da Silva S.M.P.; Crosta A.P.; Ferreira F.J.F.; Beurlen H.; Silva A.M.; dos Santos L.F.

    2010-01-01

    The objective of this study is the characterization of pegmatitic granites located in the southern region of the Borborema Pegmatitic Province (BPP) with aerial and ground gamma ray data. Ground gamma ray data, radiometric and ICP-MS laboratory analysis showed that these granites have uranium concentrations varying between 0.4 ppm and 7.8 ppm, thorium concentrations varying between 0.1 ppm and 21 ppm and potassium concentrations varying between 2% and 5.2%. Based on these radiometric characte...

  13. Aplicações das Tecnicas de Espectrometria de Massas e Ressonancia Magnetica Nuclear na Detecção e Caracterização de Intermediarios Chave de Reações Organicas

    OpenAIRE

    Liliane Girotto Cabrini

    2007-01-01

    Resumo: Esta dissertação de mestrado e dividida em duas partes. A primeira parte, visa, através da técnica de RMN, detectar e estudar a reatividade dos íons N-acilimínios endo- e exocíclicos de 5 e 6 membros, com a finalidade de verificar se o tamanho do anel, a presença de anel aromático e se a diferença entre o grupo acila endo- ou exocíclicos afetam a estabilidade do íon N-acilimínio. Experimentos realizados com a N-carbometoxi-1-metoxi-tetraidroisoquinolina (38), em CDCl3, à - 30.°C e na ...

  14. Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material; Analisis de Estano en una Ceniza de Combustion mediante Espectrometria de Masas de Ionizacion Termica con Dilucion Isotopica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.; Fernandez, M.; Quejido, A. L.

    2006-07-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound exposure time. Due to the complex matrix of this fly ash material, a two-step purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs.

  15. Impurity radionuclide analysis for the radiopharmaceutical Na[{sup 123}I] using gamma spectrometry; Analise de impurezas radionuclidicas para o radiofarmaco Na[{sup 123}I] utilizando a espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Miriam Taina Ferreira de; Silva, Ronaldo Lins da; Poledna, Roberto; Delgado, Jose Ubiratan; Andrade, Erica de Araujo Lima de; Oliveira, Antonio Eduardo de; Laranjeiras, Adilson Silva, E-mail: miriam@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Braghirolli, Ana Maria Silveira [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    During the process of manufacturing a radiopharmaceutical radionuclide impurities nature can be generated. With the need to meet the standards of ANVISA recommends that applications of doses as low as feasible in patients, the concern comes with a 'boost' that can come from these radionuclidic impurities generated in the production process and or manipulation. For Na[¹²³I] provided by IEN is important to quantify its major impurity, ¹²¹Te as well as gaining a better understanding of the parameters related to the decay scheme, since the data in the literature show discrepancies. (author)

  16. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Capdevilla, C.

    1980-07-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

  17. Detección de patrones y anomalías espectrales del terreno mediante espectrometría de imagen de alta resolución : reconocimiento, optimización y evaluación multiescenario

    OpenAIRE

    Rejas Ayuga, Juan Gregorio

    2014-01-01

    El objeto de esta Tesis doctoral es el desarrollo de una metodologia para la deteccion automatica de anomalias a partir de datos hiperespectrales o espectrometria de imagen, y su cartografiado bajo diferentes condiciones tipologicas de superficie y terreno. La tecnologia hiperespectral o espectrometria de imagen ofrece la posibilidad potencial de caracterizar con precision el estado de los materiales que conforman las diversas superficies en base a su respuesta espectral. Es...

  18. CUANTIFICACIÓN DE ARSÉNICO POR ABSORCIÓN ATÓMICA EN TERMOFORMADOS Y PELÍCULAS FLEXIBLES BIODEGRADABLES QUANTIFICAÇÃO DE ARSÊNIO POR ABSORÇÃO ATÔMICA EM TERMOFORMADOS E PELÍCULAS FLEXÍVEIS BIODEGRADÁVEIS QUANTIFICATION OF ARSENIC BY ATOMIC ABSORPTION SPECTROMETRY IN FLEXIBLE THERMOFORMED AND BIODEGRADABLE FILMS

    Directory of Open Access Journals (Sweden)

    LEIDY FERNANDA ALVIRA M

    2012-06-01

    Full Text Available Se determinó la concentración de arsénico en siete muestras de termoformados y seis muestras de películas flexibles biodegradables, por espectrometría de absorción atómica con generador de hidruros; el método de cuantificación fue curva de calibración a 193,7 nm. Previamente a ésta cuantificación, se optimizó el proceso de digestión ácida mediante reflujo (HNO3:HClO4, relación 3:1, 70°C, 3 horas para termoformados y 45 minutos para películas flexibles y se implementaron y estandarizaron los parámetros de calidad estadística (Límite de detección y cuantificación, intervalo lineal, sensibilidad de calibración, precisión y exactitud. Los resultados obtenidos fueron analizados empleando el paquete estadístico SPSS. Las concentraciones de arsénico en termoformados fueron detectables en el rango de las partes por billón mientras que las películas flexibles fueron no detectables. Hoy en día, no existe una normativa vigente que establezca los valores permitidos de Arsénico para los biopolímeros analizados.Determinou-se a concentração de arsênio em sete amostras de termoformados e seis amostras de películas flexíveis biodegradáveis, por espectrometria de absorção atômica com gerador de hidretos. O método de quantificação foi por Curva de Calibração a 193,7nm. Previamente a esta quantificação, otimizou-se o processo de digestão ácida mediante refluxo (HNO3:HClO4, relação 3:1, 70°C, 3 horas para termoformados e 45 minutos para películas flexíveis implementando e padronizando os parâmetros de qualidade estatística (Limite de detecção e quantificação, intervalo linear, sensibilidade de calibração, precisão e exatidão. Os resultados obtidos foram analisados empregando o pacote estatístico SPSS. As concentraçôes de arsênio em termoformados foram detectáveis no intervalo das partes por milhão enquanto as películas flexíveis não foram detectáveis. Hoje em dia, não existe uma normativa

  19. A estabilidade dos PAHS em função da energia da radiação interestelar nas faixas UV e raios-X

    Science.gov (United States)

    Pinotti, R.; Costa, R. K.; Boechat-Roberty, H. M.; Lago, A.; Souza, G. B.

    2003-08-01

    A nebulosa CRL 618, uma proto-nebulosa planetária cuja nuvem molecular espessa envolve uma estrela B0, contém uma grande quantidade de C2H2 e CH4. Estas moléculas são consideradas os tijolos da criação de grandes moléculas carbonadas como os Hidrocarbonetos Policíclicos Aromáticos (PAHs). Esta nebulosa, por estar exposta a intensos campos de UV e Raios-X, é uma região de fotodissociação molecular que propicia a formação de novas moléculas, confirmada pela presença de C4H2 e C6H6 (Benzeno), que é a unidade básica dos PAHs. Atribui-se a esta família de moléculas orgânicas duas propriedades fundamentais, a resistência para sobreviver ao campo de radiação UV interestelar e a geração das bandas de emissão não identificadas (UIR) observadas no infravermelho. No entanto, alguns autores questionam a resistência dos PAHs ao campo de radiação UV interestelar. Empregando a técnica de Espectrometria de Massas por Tempo de Vôo, no modo de coincidência fotoelétron-fotoíon, estudamos a ionização e fragmentação das seguintes moléculas: Benzeno, Benzeno deuterado, Naftaleno, Antraceno e Fenantreno. Utilizamos uma fonte de Hélio monocromática em 21,21 eV (584,5 Å) e a radiação Síncroton do Laboratório Nacional de Luz Síncroton (LNLS) em diferentes energias nas proximidades da borda do C 1s ( 290 eV). Comprovamos a estabilidade dos PAHs sob ação de UV (21,21 eV), onde eles apresentam um baixo nível de fotodissociação, produzindo fragmentos ionizados com rendimento total na ordem de 5 por cento em relação ao íon molecular pai. Entretanto, em altas energias, na faixa de Raios-X, a quebra destas moléculas torna-se mais intensa, com a produção de muitos fragmentos. Como uma das rotas de fragmentação do Naftaleno é [(C10H8) = > (C6H6+) + (C4H2) + (e-)], e como temos as evidências observacionais da existência do C4H2 e C6H6 na nebulosa CRL 618, sugerimos que este ambiente também possui o Naftaleno.

  20. Formulation and evaluation of mucoadhesive buccal patch of acyclovir utilizing inclusion phenomenon

    Directory of Open Access Journals (Sweden)

    Ankita Saxena

    2011-12-01

    Full Text Available Mucoadhesive buccal patch releasing drug in the oral cavity at a predetermined rate may present distinct advantages over traditional dosage forms, such as tablets, gels and solutions. A buccal patch for systemic administration of acyclovir in the oral cavity was developed using polymers hydroxy propyl methyl cellulose (K4M, hydroxy propyl methyl cellulose (K15M, sodium carboxy methyl cellulose and poly vinyl pyrolidone (K30, plasticizer poly ethylene glycol (400 and a backing membrane of Eudragit (RL100. The films were evaluated in terms of swelling, residence time, mucoadhesion, release, and organoleptic properties. The optimized films showed lower release as compared to controlled drug delivery systems. Hence, an inclusion complex of acyclovir was prepared with hydrophilic polymer hydroxylpropyl beta-cyclodextrin in the molar ratio of 1:1. The inclusion complex was characterized by optical microscopy, FAB mass spectroscopy, and FTIR spectroscopy. Patches formulated with the acyclovir inclusion complex were evaluated along the same lines as those containing acyclovir alone. The in vitro release data revealed a substantial increase from 64.35% to 88.15% in the case of PS I and PS II batches, respectively, confirming the successful use of inclusion complexes for the formulation of buccal patch of acyclovir.Mucoadesivos bucais liberadores de fármacos para a cavidade oral com taxa de liberação pré-determinada podem apresentar distintas vantagens em relação às formas farmacêuticas convencionais como comprimidos, géis e soluções. Neste trabalho, um adesivo bucal para administração sistêmica de aciclovir através da cavidade oral foi desenvolvido empregando-se os polímeros hidroxipropilmetil celulose (K4M, hidroxipropilmetil celulose (K15M, carboximetil celulose sódica e polivinil pirrolidona (K30, polietilenoglicol plastificado (400 e uma membrana suporte de Eudragit (RL100. Os filmes obtidos foram avaliados em termos de

  1. Rendimento, composição química e atividade antilisterial de óleos essenciais de espécies de Cymbopogon Yield, chemical composition and antilisterial activity of essential oils from Cymbopogon species

    Directory of Open Access Journals (Sweden)

    M.M.M Oliveira

    2011-01-01

    Full Text Available Objetivou-se determinar o rendimento, a composição química e avaliar a atividade antilisterial dos óleos essenciais de Cymbopogon citratus (DC. Stapf. (capim-limão e Cymbopogon nardus (L. Rendle (capim-citronela, puros e em combinação. A obtenção dos óleos essenciais foi realizada a partir de folhas frescas, empregando-se a técnica de hidrodestilação e utilizando-se aparelho de Clevenger modificado. Os rendimentos foram calculados a partir da massa obtida na extração e da umidade do material vegetal. A análise qualitativa foi realizada por cromatografia em fase gasosa acoplada à espectrometria de massas e a avaliação dos teores dos constituintes químicos por cromatografia em fase gasosa com detector de ionização de chamas. O efeito bacteriostático de diferentes concentrações dos óleos essenciais, puros e em combinação, foi determinado pela técnica de difusão em ágar. As concentrações mínimas inibitórias (CMIs foram utilizadas na determinação do tempo de ação bactericida. O rendimento, em base seca, foi de 1,39% (v/p para o óleo essencial de C. citratus e de 2,27% (v/p para o óleo essencial de C. nardus. Geranial e neral foram os constituintes majoritários do óleo essencial de C. citratus, enquanto, para C. nardus, foram citronelal, geraniol e citronelol. A maioria das concentrações utilizadas mostrou-se efetiva contra Listeria monocytogenes e observaram-se efeitos bactericidas nas CMIs. Óleos essenciais de C. citratus e C. nardus, puros e em combinação, constituem novas alternativas de antibacterianos naturais a serem utilizados no controle de L. monocytogenes na indústria de alimentos.The aim of this study was to determine the yield and the chemical composition of essential oils from Cymbopogon citratus (DC. Stapf. (lemongrass and Cymbopogon nardus (L. Rendle (citronella, and to evaluate their antilisterial activity when pure and combined. The essential oils were obtained from fresh leaves

  2. STUDY OF THE SPACIAL DISTRIBUTION OF ANGICO (Anadenanthera peregrina IN THE "EDMUNDO NAVARRO DE ANDRADE" STATE FOREST - RIO CLARO, SP, BRAZIL, EMPLOYING GEOSTATISTICAL METHODOLOGY = ESTUDO DA DISTRIBUIÇÃO ESPACIAL DO ANGICO (Anadenanthera peregrina NA FLORESTA ESTADUAL "EDMUNDO NAVARRO DE ANDRADE" - RIO CLARO,SP, BRASIL, EMPREGANDO METODOLOGIA GEOESTATÍSTICA

    Directory of Open Access Journals (Sweden)

    Paulo Milton Barbosa Landim

    2003-01-01

    Full Text Available Studies concerning application of geostatistical methodology to spacedistribution and mapping of plant species populations are rare. The main purpose of this study is to evaluate the application of geostatistics in detection and prediction of the space pattern of Anadenanthera peregrina "angico" at the "Edmundo Navarro de Andrade" State Forest (Rio Claro/SP. Simulations of the population data, previously mapped, were made in laboratory, by PCQ method. Using ordinary kriging interpolation technique, a map of "angicos" aggregation occurrence aggregation was generated for the area. Such method showed to be efficient to spatial analysis of the populationagglomerates, as it could be observed by overlapping the population mapped with the map of the aggregation estimates originating from sampling. This case study can contribute to the discussion of the traditional methods of botanical data sampling, proposing a new methodology for analysis using space statistics. = Os estudos pertinentes à aplicação de metodologia geoestatística nos estudos de distribuição espacial e mapeamento de populações de espécies vegetais são escassos. Este estudo objetivou avaliar o emprego da geoestatística na detecção e predição do padrão espacial de Anadenanthera peregrina "angico", em um talhão de eucaliptos naFloresta Estadual Edmundo Navarro de Andrade/Rio Claro-SP. Foram feitas simulações dos dados em laboratório, pelo método PCQ, da população previamente mapeada no campo. A partir da técnica de interpolação da krigagem ordinária, foi gerado o mapa de ocorrência de agregação de angicos na área. Tal método mostrou ser eficiente paraanalisar espacialmente os aglomerados populacionais, como pôde ser observado com a sobreposição da população mapeada com o mapa das estimativas de agregação oriundas da amostragem. Este estudo de caso pode contribuir para a discussão dos métodos tradicionais de coleta de dados botânicos, com a proposta de uma nova metodologia de análise destes dados pela estatística espacial.

  3. Proposal of requirements for performance in Brazil for systems of external individual monitoring for neutrons applying the TLD-albedo technique; Proposta de requisitos de desempenho no Brasil para sistemas de monitoracao individual externa para neutrons empregando a tecnica TLD-albedo

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Marcelo M.; Mauricio, Claudia L.P.; Pereira, Walsan W.; Fonseca, Evaldo S. da, E-mail: marcelo@ird.gov.b, E-mail: claudia@ird.gov.b, E-mail: walsan@ird.gov.b, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil).

    2009-07-01

    This work presents a criteria and conditions proposal for the regulations in Brazil of individual monitoring systems for neutrons applying the albedo technique with thermoluminescent detectors. Tests are proposed for the characterization performance of the system based on the Regulation ISO 21909 and on the experience of the authors

  4. Otimização da esterificação de ácido hexanóico com n-butanol empregando lipase (Termomyces lanuginosus imobilizada em gelatina Optimization of n-butyl hexanoate synthesis applying lipase immobilized (Termomyces Lanuginosus in gelatin

    Directory of Open Access Journals (Sweden)

    Everton Skoronski

    2013-01-01

    Full Text Available The application of Lipozyme (Termomyces lanuginosus immobilized in gelatin gel in aliphatic ester synthesis was investigated taking the esterification of hexanoic acid with n-butanol as a model reaction. Conditions were optimized by factorial design and the highest conversion was obtained under the following conditions: molar ratio alcohol: acid of 2:1, reaction time of 48 h and biocatalyst weight of 7.0 g. Under these conditions the esterification yield was around 98 %. The operational stability of the immobilized lipase was assessed and results showed that after 12 batch runs, the enzyme showed no significant loss of activity.

  5. Determinação espectrofotométrica de alumínio em concentrados salinos utilizados em hemodiálise empregando pré-concentração em fluxo Spectrophotometric aluminium determination in high salts concentrations solution used in hemodyalisis emploing preconcentration in flow injection

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Silva Pereira

    2002-11-01

    Full Text Available An automatic flow injection procedure for spectrophotometric aluminium determination in purified water and solutions containing high salts concentrations used for hemodyalisis treatment was developed. The method was base on reaction of Al3+ with cianine eriochrome R (ECR after preconcentration using the AG50W-X8 cationic-exchange resin. Elution was carried out using a 1 % (m/v calcium chloride solution. The manifold comprised an automatic proporcional injector controlled by a computer equipped with an eletronic interface and software written in QuicBASIC 4.5 with facilities to control the injector and perform data acquisition. Samples with concentration ranging from 4.96 to 19.90 µg L-1 Al were analyzed and recoveries between 88 and 113% were obtained by using the standard addition method. Other profitable analytical characteristics such as a relative standard deviation 1.3 % (n = 10 for a typical sample 14.5 µg L-1 Al, a linear response ranging up to 60.0 µg L-1Al, and a sampling throughput of 10 determinations per hour were achieved. A detection limit of 4.2 µg L-1 Al was estimated as suggested by IUPAC.

  6. Intoxicação em cães e gatos: diagnóstico toxicológico empregando cromatografia em camada delgada e cromatografia líquida de alta pressão com detecção ultravioleta em amostras estomacais

    OpenAIRE

    Bulcão, Rachel Picada; Tonello, Raquel; Piva,Sílvia Juliane; Schmitt, Gabriela Cristina; Emanuelli,Tatiana; Dallegrave, Eliane; Garcia, Solange Cristina

    2010-01-01

    Agrotóxicos e raticidas são responsáveis por inúmeras intoxicações humanas e animais. Dados preliminares sugerem que o uso ilegal desses compostos com a finalidade de intoxicação fatal em pequenos animais é uma prática comum na região central do Estado do Rio Grande do Sul. O Laboratório de Toxicologia (LATOX) recebe amostras de casos em que a principal suspeita é a intoxicação por agrotóxicos ou raticidas (lícitos e ilícitos). O presente estudo teve como objetivo apresentar um levantamento d...

  7. Rapid detection of Salmonella in foods using a combination of SPRINT TM,MSRV TM and Salmonella Latex TestTM Detecção rápida de Salmonella em alimentos empregando uma combinação de SPRINT®, MSRV® e Salmonella Latex Test®

    Directory of Open Access Journals (Sweden)

    Jane Maria Lafayette Neves Gelinski

    2002-09-01

    Full Text Available A new procedure for rapid detection of Salmonella in foods, based on the combination of SPRINT TM, MSRV TM and Salmonella Latex TestTM, was evaluated. SPRINT TM is a system to reduce the preenrichment and selective enrichment steps to 24 hours. MSRV TM is a semi-solid selective media for detection of motile Salmonella. Salmonella Latex TestTM is a rapid latex agglutination test for Salmonella. Using the three systems in combination, the total time for detection of Salmonella in a food sample is 48h. Evaluations were performed in artificially contaminated ready-to-eat baby-foods and raw Brazilian sausages (lingüiça containing no added microorganisms. The BAM conventional culture procedure was used as reference method. The study with baby foods indicated that the new procedure had good sensitivity (89% and specificity (100%, without cross-reactions with Enterobacteriaceae. However, when applied to naturally contaminated foods, the performance was poor: chi square (x² = 5.062, α> 0. 05 and Kappa-Cohen agreement (K = 0.171, p=0.089 indexes indicated that the differences between results given by the two procedures were significant and the correlation between them was low.Avaliou-se um novo procedimento para detecção rápida de Salmonella em alimentos, baseado na combinação entre SPRINT®, MSRV® e Salmonella Latex Test® . SPRINT® é um sistema para reduzir as etapas de pré-enriquecimento e enriquecimento seletivo para 24 h. MSRV® é um meio seletivo semi-sólido para detecção de salmonelas móveis. Salmonella Latex Test® é um teste rápido de aglutinação de látex. A combinação dos três sistemas permite que a detecção de Salmonella em alimentos possa ser feita em apenas 48 h. O procedimento foi avaliado em alimentos infantis prontos para consumo, experimentalmente contaminados com Salmonella exclusivamente e com uma mistura de Salmonella e várias espécies de Enterobacteriaceae e também em cem amostras de lingüiças de porco e de frango sem adição artificial de microrganismos. O método convencional de cultura foi empregado como método de referência. A avaliação em alimentos infantis indicou que o procedimento proposto apresentava boa sensibilidade (80% e especificidade (100%, sem reação cruzada com outras Enterobacteriaceae. Entretanto, quando aplicado a lingüiças, seu desempenho não foi adequado: os valores de x² (5,062, α > 0,05 e do índice de concordância de Kappa (0,171, p=0,089 indicaram que as diferenças entre os resultados obtidos pelos dois métodos foram estatisticamente significantes e a correlação entre eles foi baixa.

  8. Efeito da adubação verde do feijoeiro "da sêca" com Crotalaria juncea L., empregando-se toda a vegetação ou retirando-se do campo as hastes despojadas de suas fôlhas Sunn-hemp as a green manure for beans

    Directory of Open Access Journals (Sweden)

    H. A. A. Mascarenhas

    1967-01-01

    Full Text Available Experiências foram conduzidas, em diferentes localidades do Estado de São Paulo, para estudar o efeito da adubação verde com Crotalaria juncea L., em cultura do feijoeiro "da sêca", incorporando-se ao solo tôda a vegetação desta ou retirando-se do campo experimental as hastes despojadas de suas fôlhas. O aumento médio de produção proporcionado pela adubação verde correspondeu a 41%, no primeiro caso, mas baixou para 28%, no segundo.Sunn-hemp (Crotalaria juncea L. was tested as a green manure for beans (Phaseolus vulgaris L. in several localities of the State of São Paulo. The green manure was planted in the same area that was subsequently sown with beans. Incorporation of the whole plants or only their leaves were compared. The mean yield increase resulting from the treatments when compared with the checks was 41 % in the first case and 28 % in the second.

  9. Comparação do desempenho da lipase de candida rugosa imobilizada em suporte híbrido de polissiloxano-polivinilálcool empregando diferentes metodologias Comparative performance of Candida rugosa lipase immobilized on polysiloxane polyvinyl alcohol hybrid support using different methodologies

    Directory of Open Access Journals (Sweden)

    Ariela V. Paula

    2008-01-01

    Full Text Available The efficiency for immobilizing microbial Candida rugosa lipase on a hybrid matrix of polysiloxane polyvinyl alcohol, by adsorption, covalent coupling and encapsulation was compared. The activities of immobilized derivatives were evaluated using p-nitrophenylpalmitate (hydrolysis and butyric acid and butanol (esterification as substrates. Operational stability and storage tests were also performed. Among the procedures tested, the proposed matrix was efficient for immobilizing C. rugosa lipase by adsorption and covalent coupling techniques and unsuitable for encapsulation purposes. The results reveal that better catalytic properties in both aqueous and organic media were demonstrated by the covalent coupling POS-PVA immobilized lipase, including also satisfactory half-life and good storage stability.

  10. Eletrodissolução de ligas de latão empregando sistemas de análise em fluxo para a determinação de cobre, zinco e chumbo por ICP-AES Electrodissolution of brasses alloys employing flow systems for determination of copper, zinc and lead by ICP-AES

    Directory of Open Access Journals (Sweden)

    Ana Paula G. Gervasio

    1999-09-01

    Full Text Available An on-line electrodissolution procedure implemented in a flow injection system for determination of copper, zinc and lead in brasses alloys by ICP-AES is described. Sample dissolution procedure was carried out by using a PTFE chamber and a DC power supply with constant current. Solid sample was attached to chamber as anode and a gold tubing coupled in the chamber was used as cathode. An electrolytic solution flowing through the gold tubing closed the electric circuit with sample, in order to provide condition for electric dissolution when the DC power supply was switched on. The best results were achieved by using a 1.5 mol l-1 nitric acid solution as electrolyte and a 2.5 A current intensity. The procedure presented a good performance characterized by a relative standard deviation better than < 5% (n=5 and a sample throughput of 180 determinations per hour for Cu, Zn and Pb. Results were in agreement with those obtained by conventional acid dissolution (99% confidence level.

  11. Dot-ELISA-IgM in saliva for the diagnosis of human leptospirosis using polyester fabric-resin as support (Preliminary Report Dot-ELISA-IgM em saliva para diagnóstico da leptospirose humana, empregando como suporte tecido de poliéster-resina (Nota Prévia

    Directory of Open Access Journals (Sweden)

    Marcos Vinicius da Silva

    1994-10-01

    Full Text Available In order to improve the diagnosis of human leptospirosis, we standardized the dot-ELISA for the search of specific IgM antibodies in saliva. Saliva and serum samples were collected simultaneously from 20 patients with the icterohemorrhagic form of the disease, from 10 patients with other pathologies and from 5 negative controls. Leptospires of serovars icterohaemorrhagiae, canicola, hebdomadis, brasiliensis and cynopteri grown in EMJH medium and mixed together in equal volumes, were used as antigen at individual protein concentration of 0.2 µg/µl. In the solid phase of the test we used polyester fabric impregnated with N-methylolacrylamide resin. The antigen volume for each test was 1µl, the saliva volume was 8 µl, and the volume of peroxidase-labelled anti-human IgM conjugate was 30 µl. A visual reading was taken after development in freshly prepared chromogen solution. In contrast to the classic nitrocellulose membrane support, the fabric support is easy to obtain and to handle. Saliva can be collected directly onto the support, a fact that facilitates the method and reduces the expenses and risks related to blood processing.Com a finalidade de melhorar o diagnóstico da leptospirose humana, padronizou-se o teste dot-ELISA para a pesquisa de anticorpos específicos da classe IgM na saliva. Empregaram-se amostras de saliva e soro coletadas simultaneamente de 20 pacientes com a forma ictero-hemorrágica da doença, de 10 pacientes com outras patologias e 5 controles negativos. Culturas de Leptos-pira em meio EMJH, dos sorovares: icterohaemorrhagiae, canicola, hebdomadis, brasiliensis e cynopteri, foram utilizadas como antígeno, na concentração proteica individual de 0,2 µg/µl, misturadas em volumes iguais. Na fase sólida do teste empregou-se tecido de po-liéster impregnado com resina de N-metilol-acrilamida. O volume do antígeno para cada teste foi de 1µl, o de saliva 8µl, o de conjugado anti-IgM humana marcada com peroxidase, de 30µl. A leitura foi visual, após revelação em solução cromógena de preparo recente. O suporte de tecido é de fácil obtenção e manuseio, diferente do clássico de membrana de nitrocelulose. A saliva pode ser coletada diretamente sobre o suporte, o que facilita o método e diminui gastos e riscos inerentes à coleta e processamento do sangue.

  12. Análise das isotermas de adsorção de Cu(II), Cd(II), Ni(II) e Zn(II) pela N-(3,4-dihidroxibenzil) quitosana empregando o método da regressão não linear

    OpenAIRE

    Klug Marilene; Sanches Maria N. M.; Laranjeira Mauro C. M.; Fávere Valfredo T.; Rodrigues Clovis A.

    1998-01-01

    Adsorption of Cu(II), Ni(II), Pb(II) and Zn(II) ions from aqueous solutions by N-(3,4-dihydroxybenzyl) chitosan have been carried out. The Langmuir (L), Freundlich (F), Langmuir - Freundlich (LF), Redlich-Peterson (RP) and Tóth (T) adsorption isotherms models have been applied to fit the experimental data. Nonlinear regression computational program "Enzefitte", which is a library of the more commonly used adsorption isotherm equations for obtaining tabular outuput suitable for plotting theore...

  13. Avaliação do Risco de Contaminação de Águas Subterrâneas na Região Oeste da Bahia pelo Inseticida Carbofuran, Empregando os Modelos Attenuation Factor (AF e Retardation Factor (RF

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    Jorge Luís Oliveira Santos

    2016-02-01

    Full Text Available This work was carried out to study ground water contamination potential by the insecticide carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-methylcarbamate, the estimated profile leaching of 0 -10 cm and 10-20 cm the oxisol a soy acreage, corn, and cotton in Barreiras, Western Bahia region. The leaching parameters were assessed employing Attenuation Factor (AF and Retardation Factor (RF models, two indices used as groundwater contamination potential indicators. Based on the values for the models, it was found that the total contribution of pesticide reaching the ground, concentrated to 35% at 10 cm depth. Among these, 26% leached to a depth of 20 cm of the soil profile. The results for the models demonstrated the likelihood of contamination of groundwater by leaching of carbofuran. DOI: http://dx.doi.org/10.17807/orbital.v1i1.715

  14. Síntese de β-cetoésteres cíclicos: novo procedimento para ciclizações de Dieckmann empregando ALCL3 e trietilamina Synthesis of β-keto esters: new easy procedure for dieckmann cyclization employing aluminum chloride and triethylamine

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    Emerson P. Peçanha

    1997-08-01

    Full Text Available In this communication we describe a new methodology to Dieckmann cyclization of diethyl adipate (1 and diethyl pimelate (3 applying "push-pull" strategy using anhydrous aluminium trichloride and triethylamine in dichloromethane at room temperature. This method is very efficient, simple, safe and reproducible, giving the corresponding cyclic β-keto ester derivatives in 84% and 71% yield, respectively.

  15. Validação de método para determinação de ácidos orgânicos voláteis em efluentes de reatores anaeróbios empregando cromatografia líquida

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    Maristela Barnes Rodrigues Cerqueira

    2011-01-01

    Full Text Available This work deals with the method validation for the determination of acetic, propionic and butyric acids (VFAs in wastewaters from anaerobic reactors by HPLC-DAD. Separation was performed using a C18 column and the mobile phase composition were water pH 3.0 and methanol 90:10 (v/v. The detection and quantification was carried out at 220 nm. The method shows good linearity (r²>0.996, with adequate accuracy (89-102% and relative standard deviations lower than 18%. The matrix effect was considered low (-4.1, -3.9 and 1.4%. The developed method is fast, simple and cheap; and it was applied in wastewater samples from anaerobic reactor.

  16. Avaliação da influência de sulfetos solúveis na complexação do cobre em águas superficiais empregando métodos voltamétricos Influence of dissolved sulfides on copper complexation in surface waters using voltammetric methods

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    Elizabeth W. O. Scheffer

    2010-01-01

    Full Text Available In this work a sulfide quantification protocol using voltammetric methods was developed to evaluate the effect of dissolved sulfides on copper complexation. On the basis of pH, sulfide release from the dissociation of specific metal sulfide complexes can be electrochemically measured and then removed (as H2S by a N2 purge. Cathodic stripping square wave voltammetry (CSSWV was conducted to quantify Cu sulfides complexes which dissociate at pH < 5.0 during the process of acid titration.

  17. Determinação voltamétrica simultânea de paracetamol e cafeína e de ácido ascórbico e cafeína em formulações famacêuticas empregando um eletrodo de diamante dopado com boro

    OpenAIRE

    Bruna Cláudia Lourenção

    2010-01-01

    Neste trabalho descreve-se o desenvolvimento de procedimentos eletroanalíticos para a determinação de paracetamol, ácido ascórbico (AA) e cafeína em formulações farmacêuticas utilizando um eletrodo de diamante dopado com boro (BDD) e voltametria de pulso diferencial (DPV). Inicialmente, foram obtidos os voltamogramas cíclicos para o paracetamol, AA e cafeína separadamente sendo os potenciais de pico anódicos de oxidação de cada um destes analitos iguais a 0,80 V, 0,92 V e 1,47 V, respectivame...

  18. Removal of toxicity the pharmaceutical propranolol and your mixture with fluoxetine hydrochloride in aqueous solution using radiation with electron beam; Remocao da toxicidade do farmaco propranolol e de sua mistura com cloridrato de fluoxetina em solucao aquosa empregando irradiacao com feixe de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Boiani, Nathalia Fonseca

    2016-07-01

    Environmental health has been damage due to incorrect disposal of products and by-products. Among emerging pollutants it is possible to account with several pharmaceuticals, causing those problems when disposed in the environment by effluents. Conventional processing techniques are insufficient in removal of the pharmaceuticals, for having resistant waste and low biodegradability. Thus the advanced oxidation processes have been studied as an alternative for the treatment of different types of effluents. The objective of this study was to apply the process of irradiation with electron beam in order to reduce the toxic effects of propranolol, and the mixture with fluoxetine hydrochloride in aqueous solution. Ecotoxicological tests conducted with propranolol, and the mixture with fluoxetine hydrochloride, for Daphnia similis microcrustacean, and the Vibrio fischeri bacterium. It was observed that D. similis was more sensitive to propranolol drug and to the mixture, when compared to bacterium V.fischeri. After being subjected to the treatment with ionizing radiation, all applied doses to the propranolol and the mixture, showed significant reduction of toxicity, for D. similis. Different were the results for V. fischeri, when only 5.0 kGy reduced toxicity to propranolol. The mixture of pharmaceuticals required 2.5 and 5.0 kGy for reducing toxicity. 5.0 kGy showed the best removal efficiency for toxicity: 79.94 % for D. similis and 15.64 % for V. fischeri, when exposed to propranolol. The mixture reduction efficacy were 81.59% and 26.93 % for D.similis and V.fischeri, respectively. (author)

  19. Electro-oxidative leaching of pitchblende for uranium determination by arsenazo III spectrophotometry using fluid injection analysis system; Lixiviacao eletro-oxidativa de pechblenda para determinacao de uranio por espectrofotometria com arsenazo III empregando um sistema de analises por injecao em fluxo

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Alvaro Serafim Ferreira de

    2006-07-01

    In this work two different electro dissolution cells were projected and tested in order to solubilize pitchblende minerals aiming to posterior on line association to a flow injection system for the spectrophotometric determination of uranium leachate. The influence of current density, time, temperature, the electrolyte concentration nature, and the particle suspension density, were studied. Hydrodynamic and chemical parameters effects were evaluated to establish the best efficiency of the flow injection analysis system and to receive samples pretreated by electro oxidative leaching for the uranium determination. Arsenazo III was used as a colorimetric reagent and parameters such as acidity and reagents concentration, carrier and reagent flow rates, injection volume, reactor and reduction column size were studied and optimized. The calibration curves have showed a linear behavior (R{sup 2} = 0.9996) between the concentration range of 0.05 and 2.0 mgL{sup -1}. A relative deviation standard of 5.5 % (at 0.1 mgL{sup -1}) and a detection limit of 0.02 mgL{sup -1} were obtained, as well an analytical throughput of 60 sample determinations per hour. In the association of the flow injected analysis system with the electro-dissolution cells, values up to 98 % were obtained for the uranium extraction. The developed methodology for the electrooxidative extraction and on line spectrophotometric uranium determination in pitchblende samples, showed agreement with the reference method (ICP-MS), with a deviation between the results of less than 3.5 %. The proposal system showed advantages in relation to the conventional technique, like: automation of all analytical process, less quantities and more swiftness in the sample dissolution, less volume and acid concentration and reduction of the matrix effect. (author)

  20. Síntese, caracterização e estudos de interação de um análogo da antitoxina CcdA empregando fluorescência no estado estacionário Synthesis, characterization and interaction studies of an analog of CcdA antitoxin by steady state fluorescence

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    Camila Aparecida Cotrim

    2010-01-01

    Full Text Available Toxin-antitoxin (TA systems contribute to plasmid stability by a mechanism called post-segregational killing. The ccd was the first TA system to be discovered with CcdB being the toxin and CcdA the antitoxin. CcdA, an 8.3 kDa protein, interacts with CcdB (11.7 kDa, preventing the cytotoxic activity of CcdB on the DNA gyrase. As an approach to understanding this interaction, CcdA41, a polypeptide derived from CcdA, was synthesized by solid-phase methodology and its interaction with CcdB was analyzed by steady state fluorescence. CcdA41 formed a stable complex with CcdBET2, a peptide based on CcdB, the more recently described bacterial topoisomerase inhibitor.

  1. Descontaminação de drogas vegetais empregando irradiação gama e óxido de etileno: aspectos microbianos e químicos Decontamination of vegetal drugs using gama irradiation and ethylene oxide: microbial and chemical aspects

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    Lucilia Cristina Satomi

    2005-12-01

    Full Text Available A avaliação da qualidade sanitária de drogas vegetais, bem como a utilização de métodos de descontaminação constituem importantes etapas no que se refere ao aspecto de segurança ao consumidor, principalmente pelo fato de serem usualmente consumidas por pessoas debilitadas, por vezes imunodeprimidas. No Brasil a RDC 48/2004 menciona a pesquisa de contaminantes microbiológicos bem como o estudo da eficácia dos agentes descontaminantes. Os objetivos do presente trabalho foram avaliar os efeitos da fumigação com óxido de etileno e da irradiação gama sobre a carga microbiana, bem como determinar alterações nos constituintes químicos em amostras de Ginkgo biloba e Paulinia cupana H.B.K. (guaraná. A carga microbiana inicial foi, em média, 3,2x10(6 para microrganismos aeróbicos totais e 3,0x10(5 para fungos. Ambos os métodos de descontaminação apresentaram-se eficazes na redução da carga microbiana. As análises por cromatografia líquida de alta eficiência revelaram ausência de alterações significativas nos teores de glicosídeos flavonoídicos e cafeína, respectivamente para ginkgo e guaraná.The sanitary quality of vegetal drugs, as well as the use of decontamination methods are important steps towards the consumer safety, mainly due to the fact that these products are usually used by sick and with weak immunocompromised persons. In Brazil, the RDC 48/ 2004 mention the contamination research as well as the efficacy of the decontaminated product. The purpose of this work is to evaluate the effects of ethylene oxide fumigation and gamma irradiation on the microbial burden and some chemical constituents of ginkgo and guarana. The initial microbial burden was 3,2x10(6, on average, for total aerobic microorganisms and 3,0x10(5 for fungi. Both methods proved to be effective in the microbial burden reduction. The analyses using high performance liquid chromatography revealed the absence of significant alterations in the flavonol glycosides and caffein contents, respectively for ginkgo and guarana.

  2. Estimação de componentes de co-variância para pesos corporais do nascimento aos 365 dias de idade de bovinos Guzerá empregando-se modelos de regressão aleatória Estimates of covariance components for body weights from birth to 365 days of age in Guzera cattle, using random regression models

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    Luciele Cristina Pelicioni

    2009-01-01

    Full Text Available Um total de 19.770 pesos corporais de bovinos Guzerá, do nascimento aos 365 dias de idade, pertencentes ao banco de dados da Associação Brasileira dos Criadores de Zebu (ABCZ foi analisado com os objetivos de comparar diferentes estruturas de variâncias residuais, considerando 1, 18, 28 e 53 classes residuais e funções de variância de ordens quadrática a quíntica; e estimar funções de co-variância de diferentes ordens para os efeitos genético aditivo direto, genético materno, de ambiente permanente de animal e de mãe e parâmetros genéticos para os pesos corporais usando modelos de regressão aleatória. Os efeitos aleatórios foram modelados por regressões polinomiais em escala de Legendre com ordens variando de linear a quártica. Os modelos foram comparados pelo teste de razão de verossimilhança e pelos critérios de Informação de Akaike e de Informação Bayesiano de Schwarz. O modelo com 18 classes heterogêneas foi o que melhor se ajustou às variâncias residuais, de acordo com os testes estatísticos, porém, o modelo com função de variância de quinta ordem também mostrou-se apropriado. Os valores de herdabilidade direta estimados foram maiores que os encontrados na literatura, variando de 0,04 a 0,53, mas seguiram a mesma tendência dos estimados pelas análises unicaracterísticas. A seleção para peso em qualquer idade melhoraria o peso em todas as idades no intervalo estudado.A total of 19,770 body weight records of Guzera cattle, measured from birth to 365 days of age and supplied by the Brazilian Zebu Breeders Association, was analyzed with the following objectives of: 1 to compare different residual variances through step functions with 1, 18, 28 and 53 classes and through variance functions with orders ranging from two to five using ordinary polynomials and 2 to estimate covariance functions considering different orders for direct additive genetic effects, animal permanent environmental and maternal permanent environmental effects, using random regression models. The random effects included were modeled by regression on Legendre Polynomials with orders ranging from linear to quartic. The models were compared through the likelihood ratio test, Akaike's information criterion and the Schwarz's Bayesian information criterion. The model with 18 heterogeneous classes was the one that best fitted the residual variances, according to the statistical tests; however, the model with variance function of 5th order also showed to be appropriate. The direct heritability estimates were higher than those found in literature, ranging from 0.04 to 0.53, showing similar trends when compared to those estimated using univariate models. Selection on body weight in any age should improve the body weight in all ages in the studied interval.

  3. Análise simultânea da mirtazapina e N-desmetilmirtazapina em plasma empregando a cromatografia líquida de alta eficiência Simultaneous analysis of mirtazapine and N-demethylmirtazapine in plasma by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Ana Cecília Coragem Briguenti

    2005-12-01

    Full Text Available Para avaliação das propriedades farmacocinéticas e monitorização terapêutica da mirtazapina, antidepressivo recentemente introduzido no mercado e que vem sendo bastante utilizado, são necessários métodos de análise simples, sensíveis e seletivos. Sendo assim, a cromatografia líquida de alta eficiência com detecção por fluorescência foi empregada para o desenvolvimento de um método para análise simultânea da mirtazapina e de seu metabólito, N-desmetilmirtazapina, em plasma. Após extração líquido-líquido utilizando tolueno como solvente extrator, o fármaco, metabólito e padrão interno (metoprolol foram separados em coluna LiChrospher 100 RP-8 capeada, utilizando fase móvel composta por tampão fosfato de sódio, 0,1 mol/L, pH 3,5-acetonitrila (82:18, v/v. O método apresentou linearidade no intervalo de 2,5 a 500 ng/mL para ambos os compostos, com recuperações médias de 77 e 66% para a mirtazapina e demetilmirtazapina, respectivamente. Os limites de quantificação (2,5 ng/mL, precisão (CV < 15% e exatidão (erros relativos < 15% do método asseguram a sua aplicabilidade em estudos de disposição cinética e para o controle terapêutico da mirtazapina.

  4. Avaliação das condições reacionais para a síntese enzimática do butirato de butila empregando lipase de Candida rugosa Evaluation of the reaction conditions for the enzymatic synthesis of the butyl butyrate using lipase from Candida rugosa

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    Fabrício Maciel Gomes

    2004-06-01

    Full Text Available Lipase de Candida rugosa na forma livre foi usada na síntese de butirato de butila pela esterificação direta de n-butanolcom ácido butírico. Um planejamento fatorial completo 2(4 foi empregado para determinar a influência da razão molar do álcool para ácido (1: 0,5-2,5, concentração de agente dessecante (0-20%, concentração de enzima (40-80 mg e temperatura de incubação (30-60 °C no rendimento de esterificação. A concentração de agente dessecante foi o fator mais significativo na esterificação, sendo sua influência negativa. O progresso da esterificação foi favorecido para substratos contendo ácido em excesso, mesmo em baixa concentrações de enzima (40 mg, sendo a conversão de 50%. Na região avaliada, a formação do butirato de butila (26,67 g/L foi maximizada para razão molar (1:2,5, ausência de agente dessecante, concentração de enzima (80 mg e temperatura de incubação de 30 °C.Free lipase from Candida rugosa was used for the synthesis of butyl butyrate by direct esterification of butyric acid and butyl alcohol. A full factorial experimental design (2(4 was employed to determine the effect of alcohol to acid ratio (1: 0.5-2.5, water adsorbent concentration (0-20%, enzyme concentration (40-80 mg and incubation temperature (30-60 °C on the esterification yield. Water adsorbent concentration has been found to be the most significant factor on the esterification reaction and its influence was negative. The extent of esterification was higher for substrates containing acid in excess even with a low enzyme concentration of 40 mg and 50% conversion was observed. The maximum predicted values for butyl butyrate yield (92.67% can be attained with substrate containing acid in excess (molar ratio alcohol to acid 1:2.5, 80 mg enzyme concentration in the absence of water adsorbent at temperature incubation of 30 °C.

  5. A rapid polymerase chain reaction protocol to detect adenovirus in eye swabs Detecção de adenovírus em "swab" oftálmico empregando protocolo rápido por reação da polimerase em cadeia

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    Rodrigo Melo Mendes

    2004-06-01

    Full Text Available PURPOSE: Viruses of the Adenoviridae family are associated with many clinical syndromes, possessing 50 serotypes. These agents and viruses of the Herpesviridae family are the two major agents responsible for viral conjunctivitis, and a rapid diagnosis is important due to the epidemic character of adenoviral infections. METHODS: We developed a PCR without DNA extraction for adenovirus using primers that amplify a 300 bp fragment of the hexon capsid protein gene from many serotypes. RESULTS: Swab samples from cornea of seven patients with keratoconjunctivitis were analyzed, and one of them was PCR positive for adenovirus. The sequence of this fragment shows a 100% homology with the sequence of adenovirus type 8. CONCLUSION: Sequencing of 300 bp from the hexon gene allows to identify almost all Ad serotypes, including all serotypes related to epidemic keratoconjunctivitis (8,19,37 and almost all serotypes involved with Ad-associated conjunctivitis.OBJETIVO: Vírus da família Adenoviridae estão associados com muitas síndromes clínicas, sendo conhecidos 50 sorotipos. Vírus desta família e da família Herpesviridae são os maiores responsáveis por conjuntivite viral, sendo um rápido diagnóstico importante devido ao caráter epidêmico das infecções por adenovírus. MÉTODOS: Reação em cadeia da polimerase (PCR para adenovírus foi desenvolvida utilizando iniciadores que amplificam um fragmento de 300 bp do gene da proteína hexon do capsídeo de diversos sorotipos. A reação em cadeia da polimerase foi efetuada sem a etapa de extração de DNA. RESULTADOS: Amostras de "swabs" de córneas de sete pacientes com ceratoconjuntivite foram analisadas, sendo que uma amostra foi positiva para adenovírus. O seqüenciamento deste fragmento mostrou 100% de homologia com a seqüência do adenovírus tipo 8. CONCLUSÃO: O seqüenciamento do fragmento de 300 bp do gene do hexon permite a identificação de quase todos os sorotipos de adenovírus, incluindo aqueles relacionados com a ceratoconjuntivite epidêmica (8,19,37 e todas as amostras associadas com conjuntivite.

  6. Planejamento fatorial e superfície de resposta: otimização de um método voltamétrico para a determinação de ag(i empregando um eletrodo de pasta de nanotubos de carbono

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    Fernando Campanhã Vicentini

    2011-01-01

    Full Text Available A factorial design applied in a voltammetric stripping method for the measurement of Ag(I in natural water is described. The procedure is based on the effective pre-concentration of silver ions on electrode surface. The calibration graph was linear in the silver concentration range from 7.92 x 10"7 to 1.07 x 10"5 mol L"1 with a detection limit of 3.81 x 10-7 mol L-1. The determination of Ag(I in natural water samples was carried out satisfactory with the proposed electrode.

  7. Especiação analítica de compostos de arsênio empregando métodos voltamétricos e polarográficos: uma revisão comparativa de suas principais vantagens e aplicações Speciation analysis of arsenic compounds by voltammetric and polarographic methods: a comparative review of their main advantages and applications

    Directory of Open Access Journals (Sweden)

    Leandro Machado de Carvalho

    2004-04-01

    Full Text Available This paper provides a review on voltammetric and polarographic methods for the speciation analysis of inorganic and organic arsenic compounds in different matrices. A discussion on the main advantages of electroanalytical methods in comparison with other analytical methods employed for arsenic speciation is presented. The mechanistic aspects of the most relevant techniques employing cathodic and anodic stripping voltammetry as well as polarographic methods published in the last twenty five years are summarized and discussed. The bibliographic references cited in this work were selected from the Web of Science (published by the ISI and the main journals of analytical chemistry.

  8. Determinação voltamétrica de metais em águas e fluidos biológicos empregando mineralização de amostras com radiação ultravioleta Voltammetric determination of metals in waters and biological fluids using sample mineralization with ultraviolet radiation

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    Leandro M. de Carvalho

    2008-01-01

    Full Text Available This work describes the optimization of pretreatment steps for the destruction of organic matter in samples of waters and biological fluids, by using an UV irradiation system with a high power UV radiation source (400 W. The efficiency of the system constructed for the photo-decomposition of samples of model waters, natural waters and biological fluids was investigated by performing recovery experiments of the metallic species Zn(II, Cd(II, Pb(II, Cu(II, Al(III and Fe(III. The use of UV irradiation allowed the liberation of metals bound to the organic matrix and the determination of the total content of elements in the samples.

  9. Recommended ingestion of indispensable amino acids to young men . A study using stable isotopes, plasmatic amino acids and nitrogen balance; Ingestao recomendada de aminoacidos essenciais para individuos jovens eutroficos do sexo masculino. Estudo empregando isotopo estavel, aminoacidos plasmaticos e balanco nitrogenado

    Energy Technology Data Exchange (ETDEWEB)

    Marchini, J.S.

    1992-12-31

    It has been previously stated that the minimum physiological recommendations for the indispensable amino acids in health adults, as proposed by FAO/WHO/UNU in 1985, are far too low, except for the methionine. An amino acid stable isotopic kinetic study was conducted to seek further experimental support to this hypothesis. Twenty healthy young men received an l-amino acid based diet, supplying 140 mg N.kg{sup -1}.d{sup -1}, patterned on egg protein for 1 week, then for 3 weeks either (i) a pattern based on current international recommendations (FAO diet, n=7), (ii) a the tentative Laboratory of Human Nutrition of the Massachusetts Institute of Technology, new amino acid recommendation pattern (MIT diet, n=7) or (iii) again the egg hen pattern (EGG diet, n=6). All subjects were again studied for one final, consecutive week of the egg diet. At the end of the initial week, at the first and third week with the three experimental diets,and after three days following the return of the egg diet, an 8 h primed continuous intravenous infusion with l-{sup 13} C-leucine was conducted (3 h, fast, 5 h fed - while subjects received hourly meals supplying the equivalent of 5/12 total daily intake). Estimation of leucine balance were carried out with measurements plasma free amino acids changes. Daily nitrogen balances were obtained through the study. Interpretation of plasma amino acids profile, and changes of leucine kinetics balances, indicated that the FAO diet was not able to maintain amino acids homeostasis whereas the MIT and the egg diets sustained body amino acids equilibrium with a positive amino acid balance. Nitrogen balances tended to be more negative with the FAO diet but failed to show statistically significant differences among the three diets. The finding point out that it would be prudent to use the new, tentative recommended amino acid pattern (MIT diet 0 as the minimum physiological amino acid needs of healthy human adults). (author). 161 refs., 8 figs., 19 tabs.

  10. Determinação simultânea de cátions empregando eletroforese capilar com detecção condutométrica sem contato em equipamento construído em laboratório Simultaneous determination of cations by capillary electrophoresis with contactless conductivity detection performed in a home-made equipment

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    Leandro M. de Carvalho

    2009-01-01

    Full Text Available This work describes the development of a home-made capillary electrophoresis (CE system based on the capacitively coupled contactless conductivity detection (C4D for the separation of the metallic species Zn2+, Cr3+, Pb2+, Cd2+, Co2+, Cu2+, Ni2+ e Tl+. A background electrolyte composed of MES/Histidine 0,02 mol L-1 (pH 5.0 was optimized for the separation of the metallic species by using organic solvents and complexing agents as additives. The system allowed the determination of the metallic species using MES/Histidine 0,02 mol L-1 and methanol 5% (pH 5.0 as a background electrolyte, 15 kV separation voltage and hydrodynamic injection by gravity.

  11. Radiographic cephalometric study using Ricketts analysis for dentoskeletal patterns evaluation of patients having class II, division I malocclusion treated during mixed dentition period; Estudo cefalometrico radiografico empregando a analise de Ricketts na avaliacao dos padroes dento-faciais de pacientes portadores de maloclusao de classe II, divisao I, tratados durante a fase de denticao mista

    Energy Technology Data Exchange (ETDEWEB)

    Motta e Albuquerque, Carmen da

    1988-12-31

    In the specialized literature about the use of extra oral forces in the treatment of the Class II malocclusion one can observe that it has been used more and more, with the objective of achieving teeth improvement and bone as well. It is proposed to evaluate the extent of the orthodontic/orthopedic modifications and their influence in the facial pattern of patients with those malocclusions, treated during the mixed dentition period. A sample of 32 patients of both sexes, leucoderms, with Class II, division I malocclusion, between 7 and 14 years old, were studied employing a cephalometric radiographic method for evaluation. (author). 94 refs., 11 figs., 15 tabs.

  12. Effect of the kind of fuel in the synthesis of the catalyzer NiFe{sub 2}O{sub 4} to displacement reaction of water gas (WGRS); Efeito do tipo de combustivel na sintese do catalisador NiFe{sub 2}O{sub 4} para reacao de deslocamento do gas agua (WGRS)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, P.T.A.; Barros, B.S.; Costa, A.C.F.M.; Gama, L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais], e-mail: anacristina@dema.ufcg.edu.br; Jesus, A.A.; Andrade, H.M.C. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2006-07-01

    This work has as objective synthesizes and to characterize the NiFe{sub 2}O{sub 4} catalyst by combustion reaction using different fuels: urea and glycine seeking your application in the water gas shift reaction (WGSR), promoting the purification of the methane for the elimination of the carbon monoxide. The powders were prepared in agreement with the chemistry of the propellants using as recipient a vitreous silica crucible; the maximum temperature and the medium time of flame were verified. The powders were characterized by X-ray diffraction (DRX), Scanning electronic microscopy and catalytic tests. The results show that the catalysts presented inverse spinel structure as majority phase for the two types of fuels. However, it was observed that using the urea, there was the presence of a second phase of NiO and when the glycine was used, there was the presence of lines of Ni. The catalyst NiFe{sub 2}O{sub 4} using urea as fuel, presented better catalytic acting. (author)

  13. Analysis of the influence of fuel on NiFe{sub 2}O{sub 4} nanocrystalline obtained by solution combustion synthesis; Influencia do tipo de combustivel sobre NiFe{sub 2}O{sub 4} nanocristalina obtida a partir da sintese por combustao em solucao

    Energy Technology Data Exchange (ETDEWEB)

    Dalt, S. Da; Bergmann, C.P., E-mail: silvana.da.dalt@ufrgs.b [Universidade Federal do Rio Grande do Sul (LACER/UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Lab. de Materiais Ceramicos

    2009-07-01

    This paper investigates the effect of different fuels used on a structural properties stoichiometric composition of NiFe{sub 2}O{sub 4} obtained from the combustion synthesis. Precursor solutions were prepared from iron nitrate nonahydrate and nickel nitrate hexahydrate, and complexing agents as maleic anhydride, oxalic acid and sucrose. The samples were characterized by X-ray diffraction to evaluate the presents phases, and crystallite size from single-line method, specific surface area (BET) and scanning electron microscopy (SEM) for morphological analysis of powders. The results indicate that NiFe{sub 2}O{sub 4} can be obtained after heat treatment at 800 deg C with particle size of approximately 60nm. (author)

  14. Use of phyllosilicates in electrochemical devices: possible use of sepiolite as a support of catalysts in direct alcohol fuel cells (DAFC); Utilizacao de filosilicatos em dispositivos eletroquimicos: possivel uso da sepiolita como suporte de catalisadores em celulas a combustivel com uso direto de etanol (DAFC)

    Energy Technology Data Exchange (ETDEWEB)

    Parra-Silva, J.; Silva, A.C.; Mello-Castanho, S.R.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cerpa, A. [Universidad Europea de Madrid, Madrid (Spain)

    2014-07-01

    Direct alcohol Fuel cells (DAFC) are interesting to use Brazil for reasons of fuel logistics and availability. The catalysts used in these devices to promote the oxidation of alcohol at the anode need to be fixed on a substrate which must provide high specific surface area, porosity, chemical and thermal resistance, this target can be achieved with the characteristics sepiolite. This paper proposes sepiolite as catalyst support for DAFC. Sepiolite is a phyllosilicate with double layered tetrahedral silicon cells and fibrillar structure. Catalysts (Pt / Sb / Sn) were prepared by cation substitution method and tested by cyclic voltammetry. Techniques as XRD and FT-IR were also used for characterizing materials. Was obtained up to 35 mA / g (Pt) peak current (redox ethanol) indicating the possibility of sepiolite technology development to use un proposed purpose. (author)

  15. Characterization of cathode materials SrCoO3 and La0,2Sr0,8CoO3 for use in solid oxide fuel cells (SOFC); Caracterizacao de materiais catodicos SrCoO3 e La0,2Sr0,8CoO3 para aplicacao em celulas a combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, G.O.; Aquino, F.M; Silva, R.M.; Medeiros, I.D.M. de, E-mail: gabriela.galvao@cear.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil)

    2016-07-01

    Mixed oxide ceramics with chemical structure of ABO{sub 3} type are promising candidates for cathodes of solid oxide fuel cells (SOFC) for performing well on the electrical conductivity and thermal stability. Various methods of preparation have been studied and used for the synthesis of these materials. In this study, SrCoO{sub 3} and La{sub 0,2}Sr{sub 0,8}CoO{sub 3} perovskites were synthesized using gelatin as directing agent with the purpose of producing homogeneous and porous particles. The powders obtained at 350 ° C / 2 h were calcined at 600, 800 and 1000 ° C for 4 hours and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that gelatin is a good polymerizing agent for metal ions as the material showed characteristic peaks of perovskite, with good porosity and uniformity. Furthermore, the method of synthesis employed has advantages related to cost and toxicity, which are very low. (author)

  16. Study of synthesis routes and processing of NiO-YSZ ceramic composite for use as anode in solid oxide fuel cell (SOFC); Estudo de rotas de sintese e processamento ceramico do composito NiO-YSZ para aplicacao como anodo em celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Yoshito, Walter Kenji

    2011-07-01

    This study aim the definition of synthesis and ceramic processing conditions of the anodic component suitable for operation of SOFC, i.e, homogeneous distribution of NiO in YSZ matrix and porosity after reduction above 30%. The selected synthesis routes included the co-precipitation in ammonia media, mechanical mixing of powders and combustion reaction from nitrate salts. The characterization techniques of powders included the X-ray diffraction, scanning and transmission electron microscopy, laser diffraction, nitrogen gas adsorption technique (BET) and Helium pycnometry. The obtained results indicated that the loss of Ni{sup 2+} in co-precipitation process, due to the formation of complex [Ni(NH{sub 3}){sub n}]{sup 2+}, can be minimized by controlling the pH around 9.3, keeping the concentration of nickel cation in the solution to be precipitated around 0.1M. In the mechanical mixing method the best condition of powder dispersion, without differential sedimentation, was obtained for zeta potential values at pH around 8.0, fixing the dispersant concentration at 0.8%. For the combustion synthesis it was observed that when stoichiometric and twofold stoichiometric urea was used, amorphous phase was formed and a higher surface area was attained in the final products. Employing the fuel-rich solution condition, crystallization of the powder was observed and the relative intensity of reflections of XRD patterns increased with excess of fuel, due to increasing the reaction temperature. Sinterability studies of pellets prepared from powder synthesized by the three routes described above showed the temperature around 1300 deg C for maximum rate densification and porosity between 6.0 and 14%. Reduction results of the composites confirmed that the reduction kinetics occurs in two steps. The first one with a linear behavior and controlled by chemical reaction on the surface. The second reduction step is the reduction that is controlled by gas diffusion in micro pores, generated by reduction of nickel oxide, decreasing the rate of reduction. (author)

  17. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells; Estudo da reacao de reducao do oxigenio utilizando eletrocatalisadores a base de Pt-terras raras (La, Ce, Er) para aplicacao em celulas a combustivel tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Thiago Bueno

    2013-07-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  18. Guidelines for implementation of an environmental management system in the nuclear fuel cycle: a case study of USEXA-CEA; Diretrizes para implantacao de um sistema de gestao ambiental no ciclo do combustivel nuclear: estudo de caso da USEXA-CEA

    Energy Technology Data Exchange (ETDEWEB)

    Mattiolo, Sandra Regina

    2012-07-01

    The environmental management standards are intended to provide to the organizations the elements needed for the implementation of an Environmental Management System (EMS) that can be effectively integrated to another management requirements and assist them to achieve their environmental and economic goals. The Uranium Hexafluoride Production Unit - USEXA, located at the Navy Technological Center in Sao Paulo, will be the first Brazilian industrial plant responsible for the conversion stage in the nuclear fuel cycle (production of uranium hexafluoride - UF6), allowing added-value to the uranium ore. The EMS proposed to USEXA in this project allows to regulate its interfaces with the environment, since the Standards of CNEN - National Commission of Nuclear Energy and of the IAEA - International Atomic Energy Agency for Nuclear Installations, aim, mostly, to attend the security criteria for the population and the environment, concerning ionizing radiation. This model of EMS fills the gaps in standards of IAEA and CNEN, since it takes into account the environmental impacts from the use of chemicals in the manufacturing process of UF6, and general aspects of sustainability. It can be considered an original contribution within the complex activities that includes the uranium processing in the nuclear fuel cycle. This research proposes, as result, the use of a filter of significance to evaluate the environmental impacts depending on the installation location. It is also presented the Management System Manual for USEXA and models for training in personnel management are suggested, such as coaching and neuro linguistic programing, which can be applied to any Management System. The training can be considered a preventive action as they considerably decreased incidents related to equipment maintenance and thus the occurrence of environmental impacts. (author)

  19. Optimization through experiment planning for determination of experimental conditions which guarantees the metrological reliability for analysis of chloride and sulfate in fuel alcohol; Otimizacao via planejamento de experimento para determinar as condicoes experimentais que garantam confiabilidade metrologica para analise de cloreto e sulfato em alcool combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Souza e Silva, Renata; Araujo, Thiago de Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias, RJ (Brazil)], Emails: rsouza@inmetro.gov.br, toaraujo@inmetro.gov.br; Aguiar, Paula Fernandes de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)], E-mail: pfaguiar@ufrj.br

    2009-07-01

    This work presents a method of analysis to determine chloride and sulfate in fuel alcohol which allowed eliminate or minimized the matrix effect in sample of fuel alcohol, using the Doehlert planning for the stage of optimization.

  20. Studies on the efficiency during reactivation of a generation system based on natural gas reformer and a 5 k W fuel cell; Estudos de eficiencia durante reativacao de um sistema de geracao baseado em reformador de gas natural e celula a combustivel de 5 kW

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Francisco da Costa; Furtado, Jose Geraldo de Melo; Silva Junior, Fernando Rodrigues da; Serra, Eduardo Torres [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mail: fcl@cepel.br

    2008-07-01

    Fuel cell based power generation systems have been pointing as promising technology for stationary applications mainly to supply power to critical loads. Among several types of fuel cells the Polymer Electrolyte Membrane Fuel Cells (PEMFC) are the main type used around the world. Nowadays reformers are widely employed to produce hydrogen for fuel cells. The Fuel Cell Laboratory of CEPEL has a power plant based on a 5 kW PEMFC and a natural gas reformer. For a long time the PEMFC was inoperable due to reformer malfunctioning and during this time the full power availability of PEMFC was lost due to deactivation of its catalytic sites. In most cases this deactivation is reversible. So it was started a reactivation process aiming to recover the full operational condition of the PEMFC unit. During this process the gas flow relationship and efficiency of the reformer were studied. An analysis of the PEMFC reactivation was conducted where it was noted that the reactivation took place as expected. During the reactivation process the PEMFC and the whole system efficiency were analyzed. The results suggest that the PEMFC can reach efficiency compatible with conventional power generation systems thus allowing PEMFC technology to compete with these energy sources in point of efficiency. (author)

  1. Analysis for impedance electrochemistry 'on-line' of membrane/electrode assemble (MEA) of protons exchange membrane fuel cells (PEMFC); Analise por impedancia eletroquimica 'on-line' de conjuntos eletrodos/membrana (MEA) de celulas a combustivel a membrana polimetrica (PEMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Rodolfo dos

    2007-07-01

    This work reports results of studies and characterization on membrane electrode assemblies (MEAs) for proton exchange membrane fuel cell (PEMFC). Some cell operation conditions and different processes of MEA production were investigated. The electrochemical impedance spectroscopy technique (EIS) (in situ - 0 to 16 A) was used 'on-line' as a tool for diagnosis, concerning the cell performance. The EIS measurements were carried out with a FC350 Fuel Cell EIS System (GAMRY), coupled to a PC4 potentiostat/galvanostat and connected to the electronic load (TDI) for 'on-line' EIS experiments (100 mHz - 10 kHz, dU = 5 mV). MEAs with 25 cm{sup 2} surface area, using PtM/C 20% (M Ru, Sn or Ni) electrocatalysts were manufactured using the alcohol reduction process (ARP). The catalytic ink was applied directly into the carbon cloth (GDL) and pressed in the Nafion membrane (105). MEAs using Pt/C and Pt Ru/C 20% from E-TEK electrocatalysts were manufactured by comparison. All the cathodes were sprayed with Pt/C 20% from E-TEK. The noble metal concentrations used were set to 0.4 mg Pt.cm{sup -2} at the anode and 0.6 mg Pt.cm{sup -2} at the cathode (E-TEK). Nyquist diagrams of the MEAs with Pt/C and PtRu/C from E-TEK or PtM/C (M = Ru, Sn or Ni) ARP showed essentially the same ohmic resistances for the MEAs. This fact can be explained by suppression of agglomerates during the MEA preparation process or by the homogeneity of the anchored electrocatalysts at the carbon surface. It could also be observed, at low current densities, that there was a significant performance difference between the electrocatalysts from E-TEK and those prepared with the alcohol reduction process. The polarization curves results confirmed that the Pt M/C (M = Ru, Sn or Ni) ARP showed an activity increase for the methanol and ethanol fed cells. The technique of EIE was shown efficient for the evaluation of the method preparation of MEAs and the acting of the cell, the results of EIE showed coherence in the choice of the model the electric circuit for MEAs using hydrogen, methanol and ethanol. This coherence indicates that other resistances no considered in the model are not relevant in the total resistance of MEAs. (author)

  2. Study and development of membrane electrode assemblies for Proton Exchange Membrane Fuel Cell (PEMFC) with palladium based catalysts; Estudo e desenvolvimento de conjuntos membrana-eletrodos (MEA) para celula a combustivel de eletrolito polimerico condutor de protons (PEMFC) com eletrocatalisadores a base de paladio

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, Rafael Nogueira

    2013-07-01

    PEMFC systems are capable of generating electricity with high efficiency and low or no emissions, but durability and cost issues prevent its large commercialization. In this work MEA with palladium based catalysts were developed, Pd/C, Pt/C and alloys PdPt/C catalysts with different ratios between metals and carbon were synthesized and characterized. A study of the ratio between catalyst and Nafion Ionomer for formation of high performance triple-phase reaction was carried out, a mathematical model to implement this adjustment to catalysts with different relations between metal and support taking into account the volumetric aspects of the catalyst layer was developed and then a study of the catalyst layer thickness was performed. X-ray diffraction, Transmission and Scanning Electron Microscopy, X-ray Energy Dispersive, Gas Pycnometry, Mercury Intrusion Porosimetry, Gas adsorption according to the BET and BJH equations, and Thermo Gravimetric Analysis techniques were used for characterization and particle size, specific surface areas and lattice parameters determinations were also carried out. All catalysts were used on MEAs preparation and evaluated in 5 cm{sup 2} single cell from 25 to 100 °C at 1 atm and the best composition was also evaluated at 3 atm. In the study of metals for reactions, to reduce the platinum applied to the electrodes without performance losses, Pd/C and PdPt/C 1:1 were selected for anodes and cathodes, respectively. The developed MEA structure used 0,25 mgPt.cm{sup -2}, showing power densities up to 550 mW.cm{sup -2} and power of 2.2 kW{sub net} per gram of platinum. The estimated costs showed that there was a reduction of up to 64.5 %, compared to the MEA structures previously known. Depending on the temperature and operating pressure, values from US$ 1,475.30 to prepare MEAs for each installed kilowatt were obtained. Taking into account recent studies, it was concluded that the cost of the developed MEA is compatible with PEMFC stationary application. (author)

  3. Study of the Nafion quantity effect in membrane and electrodes assemblies (MEAs) of 50 cm{sup 2} used in type proton exchange membrane (PEM) fuel cell operating with H{sub 2}/Air; Estudo do efeito da quantidade de Nafion em MEAs de 50 cm{sup 2} utilizadas em celula a combustivel tipo PEM operando com H{sub 2}/ar

    Energy Technology Data Exchange (ETDEWEB)

    Profeti, Demetrius; Colmati, Flavio; Carlindo, Adao A.J.; Paganin, Valdecir A.; Gonzalez, Ernesto R.; Ticianelli, Edson A. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: dprofeti@iqsc.usp.br

    2008-07-01

    The performance of a proton exchange membrane fuel cell (PEMFC) was investigated with the aim at characterizing the effects of the Nafion. content on the scale-up of the electrodes from 5 to 50 cm{sup 2}. It is observed that a diminution of the single cell performance occurred when the electrode area is increased from 5 to 50 cm{sup 2}. The tests carried out with different Nafion. contents, and fuel cell and humidifiers at the same temperature (T{sub cell}=T{sub H2}=T{sub air}=70 deg C) showed a slightly decrease of the fuel cell performance compared to the tests performed at different temperatures (T{sub cell}=70 deg C, T{sub H2}=85 deg C, T{sub air}=75 deg C). In the study of the variation on the Nafion. contents, the higher performance up to a current density of 0.8 A cm-2 is obtained with the 35.5 wt.% Nafion.. On the other hand, at higher current densities values, the performance of the fuel cells is very similar for the 31.0, 35.5 and 39.4 wt.% Nafion contents. (author)

  4. Preliminary analysis for implementation of a hybrid solar-wind system with storage of electrical energy generated through electrolytic hydrogen and fuel cells; Analise preliminar para implementacao de um sistema hibrido solar-eolico com armazenamento da energia eletrica gerada atraves de hidrogenio eletrolitico e celula a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Daniel Gabriel; Furlan, Andre Luis; Lopes, Davi Gabriel [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica], e-mail: danielg@fem.unicamp.br; Silva, Ennio Peres; Apolinario, Fernando Resende [Universidade Estadual de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Lab. de Hidrogenio; Silva, Maria Eugenia Vieira da; Rocha, Paulo Alexandre Costa [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Mecanica e de Producao; Codeceira Neto, Alcides [Companhia Hidro Eletrica do Sao Francisco (CHESF), Recife, PE (Brazil)

    2008-07-01

    Due to relevance of the study and applicability of hybrid electric power generation from solar photovoltaic and wind power in Brazil, the present paper aims to introduce briefly the importance of technical and economic comparison of two electrical energy storage technologies (batteries versus H2 + fuel cell) and also to indicate the previous difficulties related to this possible application. In this context, it was intended a partnership between State University of Campinas - UNICAMP, the Federal University of Ceara - UFC and Hydro Electric Company of the Sao Francisco - CHESF in the meaning of makes viable an implementation. (author)

  5. Exploratory study on the integration of fuel cell systems inside the chloro-soda plants for utilization of industrial hydrogen; Estudo exploratorio da integracao de sistemas de celula a combustivel dentro das plantas de cloro-soda para utilizacao do hidrogenio industrial

    Energy Technology Data Exchange (ETDEWEB)

    Braga, Jose Mauro Fernandes [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Escola de Engenharia]. E-mail: jmfbraga@oi.com.br; Seidl, Peter [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Pirro e Longo, Waldimir [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Nwcleo de Estudos Estrategicos (NEST)

    2008-07-01

    This work aims to demonstrate the economic viability of the application of industrial hydrogen in fuel cell systems by analyzing the advantages and disadvantages of this investment in hydrochloric acid/ sodium hydroxide plants. Using the Present Liquid Value and the Real Options Theory an economic evaluation will be made of the integration of fuel cell system in these plants, based on investment cost, volatility, among other parameters. (author)

  6. Comparative analysis between two systems to generate electric energy for isolated community in the interior of the Amazon state: fuel cells with natural gas reformer versus diesel generation; Analise comparativa entre dois sistemas de geracao de energia eletrica para a comunidade isolada no interior do estado do Amazonas: celula a combustivel com reformador para gas natural versus gerador diesel

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Paula Duarte; Bergamini, Cristiane Peres; Camargo, Joao Carlos; Lopes, Daniel Gabriel [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica; Esteves, Gheisa Roberta Telles [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo de Pesquisas e Estudos Ambientais; Silva, Ennio Peres da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin

    2004-07-01

    Although great part of the domestic territory is already supplied with electric energy, still there are many regions where the system is precarious or nonexistent, generically called isolated communities. In the majority of the cases these communities are supplied with Diesel oil generators and the substitution of this fuel for available alternative energy in the localities has been object of study of some institutions of research spread throughout the country. Currently, the use of fuel cells has been strongly argued in the generation of electric energy associated with the local energy necessity, from the use of a regional fuel and this is due to the high efficiency of allied energy conversion to the low ambient impacts that this equipment offers. Most of the different types of fuel cells use hydrogen as a fuel to produce electricity, and it is extracted from renewable or non-renewable sources of energy. Then, the article has the objective of comparing in first analysis the energy efficiency and the cost between the two systems: the ones used currently in the great majority of the isolated communities, constituted of a Diesel engine-generator system, with Natural Gas Reformer System/ Purifier of Hydrogen/ Fuel Cell/ and to analyze if such project presents characteristics that qualifies it to get the carbon credits proposed in the Mechanism of Clean Development. (author)

  7. Oxy-fuel technology - Rebox flameless - for reheating and annealing furnaces to increase capacity and reduce operation costs - industrial results; Tecnologia oxi-combustivel - Rebox 'flameless' - em fornos de reaqucimento e recozimento par aumento da capacidade produtiva e reducao dos custos energeticos - resultados industriais

    Energy Technology Data Exchange (ETDEWEB)

    Kfouri, Carlos Eduardo [The Linde Group, Munich (Germany). Iron Foundry and Steel; Nunes, Paulo Rogerio [The Linde Group, Munich (Germany). Metalurgia; Lugnet, Anders [The Linde Group, Munich (Germany). Steel Application Development; Scheele, Joachim von [The Linde Group, Munich (Germany). Metals and Glass Industries

    2010-07-01

    Most steel producers need solutions for higher production throughput in their reheat and annealing furnaces. The goals are to sell more and to improve utilization of investments in existing rolling mills and annealing operations, but also to facilitate the possible restructuring of business and to better manage peak volume demand. Additional throughput capacity also allows for repair and maintenance activities. Removing the nitrogen ballast from the combustion and heat transfer process improves furnace operation drastically. It has in over 120 all Rebox oxy fuel installations been reported that if replacing the combustion air with industrial grade oxygen, that furnace throughput can be boosted by up to 50%, and fossil fuel consumption cut by 50%. It facilitates the use of low-grade fuels since the necessary high flame temperatures can be achieved. Rebox is compact and powerful for a cost-effective retrofit in an existing or new furnace. It complies with ever-stricter requirements for emissions of CO{sub 2} and NO{sub x}. (author)

  8. Application of PtSn/C catalysts and Nafion SiO{sub 2} membranes in direct ethanol fuel cell at high temperatures; Aplicacao de catalisadores PtSn/C e membranas Nafion SiO{sub 2} em celulas a combustivel de etanol direto em elevadas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Dresch, Mauro Andre

    2014-07-01

    This work has as objective to evaluate anodes and electrolytes in direct ethanol fuel cells (DEFC) operating at high temperature (130 deg C). As anode materials, electrocatalysts based on Pt Sn/C were prepared by Modified Polyol Method with various Pt:Sn atomic ratios. Such methodology promotes self organized electrocatalysts production with narrow particle size distribution and high alloying degree. The electrocatalysts were characterized by XRD, and CO stripping. The results showed that these materials presented high alloying degree and Eonset CO oxidation at lower potential as commercial materials. As electrolyte, Nafion-SiO{sub 2} hybrids were synthesized by sol-gel reaction, by the incorporation of oxide directly into the ionic aggregates of various kinds of Nafion membranes. The synthesis parameter, such sol-gel solvent, membrane thickness and silicon precursor concentration were studied in terms of silica incorporation degree and hybrid mechanical stability. Finally, the optimized anodes and electrolytes were evaluated in DEFC operating at 80 - 130 deg C temperature range. The results showed a significant improvement of the DEFC performance (122 mW cm{sup -2}), resulted from the acceleration of ethanol oxidation reaction rate due to anode material optimization and high temperature operation once the use of hybrids possibilities the increase of temperature without a significant conductivity loses. In this sense, the combination of optimized electrodes and electrolytes are a promising alternative for the development of these devices. (author)

  9. Development of a membrane electrode as assembly production process for proton exchange membrane fuel cell (PEMFC) by sieve printing; Desenvolvimento de processo de producao de conjuntos eletrodo-membrana-eletrodo para celulas a combustivel baseadas no uso de membrana polimerica conditora de protons (PEMFC) por impressa a tela

    Energy Technology Data Exchange (ETDEWEB)

    Bonifacio, Rafael Nogueira

    2010-07-01

    Energy is a resource that presents historical trend of growth in demand. Projections indicate that future energy needs will require a massive use of hydrogen as fuel. The use of systems based on the use of proton exchange membrane fuel cell (PEMFC) has features that allow its application for stationary applications, automotive and portable power generation. The use of hydrogen as fuel for PEMFC has the advantage low pollutants' emission, when compared to fossil fuels. For the reactions in a PEMFC is necessary to build membrane electrode assembly (MEA). And the production of MEAs and its materials are relevant to the final cost of k W of power generated by systems of fuel cell. This represent currently a technological and financial barriers to large-scale application of this technology. In this work a process of MEAs fabrication were developed that showed high reproducibility, rapidity and low cost by sieve printing. The process of sieve printing and the ink composition as a precursor to the catalyst layer were developed, which allow the preparation of electrodes for MEAs fabrication with the implementation of the exact catalyst loading, 0.6 milligrams of platinum per square centimeters (mgPt.cm{sup -2}) suitable for cathodes and 0.4 mgPt.cm{sup -2} for anode in only one application step per electrode. The ink was developed, produced, characterized and used with similar characteristics to ink of sieve printing build for other applications. The MEAs produced had a performance of up to 712 m A.cm{sup -2} by 600 mV to 25 cm{sup 2} MEA area. The MEA cost production for MEAs of 247.86 cm{sup 2}, that can generate 1 kilowatt of energy was estimated to US$ 7,744.14 including cost of equipment, materials and labor. (author)

  10. Preparation and characterization of Nafion - TiO{sub 2} composite electrolytes for application in proton exchange membrane fuel cells; Preparacao e caracterizacao de eletrolitos compositos Nafion - TiO{sub 2} para aplicacao em celulas a combustivel de membrana de troca protonica

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Bruno Ribeiro de

    2008-11-06

    The fabrication and characterization of Nafion - TiO{sub 2} composites, and the use of such electrolytes in PEM (Proton Exchange Membrane) fuel cell operating at high temperature (130 deg C) were studied. The operation of a PEM fuel cell at such high temperature is considered as an effective way to promote fast electrode reaction kinetics, high diffusional transport, and high tolerance to the carbon monoxide fuel contaminant. The polymer Nafion{sup R} is the most used electrolyte in PEM fuel cells due to its high proton conductivity. However, the proton transport in Nafion is dependent on the water content in the polymeric membrane. The need of absorbed water in the polymer structure limits the operation of the fuel cell to temperatures close to 100 deg C, above which Nafion exhibits a fast decrease of the ionic conductivity. In order to increase the performance of the electrolyte operating at high temperatures, Nafion-TiO{sub 2} composites have been prepared by casting. The addition of titania hygroscopic particles to the polymeric matrix aims at the enhancement of the humidification of the electrolyte at temperatures above 100 deg C. Three types of titania particles with different specific surface area and morphology have been investigated. Nafion-based composites with the addition of titania nanoparticles, in the 2.5-15 wt.% range, with nearly spherical shape and specific surface area up to approx. 115 m{sup 2}g{sup -1} were found to have higher glass transition temperature than the polymer. Such an increase improves the stability of the electrolyte during the fuel cell operation at high temperatures. The addition of titania-derived nanotubes results in a pronounced increase of the performance of PEM fuel cell operating at 130 deg C. In this composite, the high specific surface area and the tubular shape of the inorganic phase are responsible for the measured increase of both the absorption and retention of water of the composite electrolyte. Nonetheless, the polarization curves of fuel cell using the composite electrolytes exhibited an increase of the ohmic polarization associated with the addition of the insulating titania particles. As the chemical structure of Nafion was observed to be insensitive to the addition of the inorganic particles, the high performance of the composite electrolytes is a result of competing effects: the decrease of the electrical conductivity and a higher thermal stability or water absorption/retention capacity. The experimental results suggest that the Nafion-TiO{sub 2} composites are promising electrolytes for PEM fuel cells operating at temperatures above approx. 100 deg C. (author)

  11. The method of the maximum entropy for the reconstruction of the distribution bolt the bolt of the neutrons flow in a fuel element; O metodo da maxima entropia para a reconstrucao da distribuicao pino a pino do fluxo de neutrons em um elemento combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Ancalla, Lourdes Pilar Zaragoza

    2005-04-15

    The reconstruction of the distribution of density of potency pin upright in a heterogeneous combustible element, of the nucleus of a nuclear reactor, it is a subject that has been studied inside by a long time in Physics of Reactors area. Several methods exist to do this reconstruction, one of them is Maximum Entropy's Method, that besides being an optimization method that finds the best solution of all the possible solutions, it is a method also improved that uses multipliers of Lagrange to obtain the distribution of the flows in the faces of the combustible element. This distribution of the flows in the faces is used then as a contour condition in the calculations of a detailed distribution of flow inside the combustible element. In this work, in first place it was made the homogenization of the heterogeneous element. Soon after the factor of the multiplication executes and the medium values of the flow and of the liquid current they are computed, with the program NEM2D. These values medium nodal are, then, used upright in the reconstruction of the distribution pin of the flow inside the combustible element. The obtained results were acceptable, when compared with those obtained using fine mesh. (author)

  12. Electrolytic hydrogen production at off-peak consumption and his utilization as energy vector at peak consumption through use of fuel cells; Producao de hidrogenio eletrolitico nos horarios fora de ponta e sua utilizacao como vetor energetico nos horarios de ponta atraves do uso de celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Gambetta, Francielle [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: fgambetta@fem.unicamp.br; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica. Lab. de Hidrogenio

    2008-07-01

    Due the fact that consumers have different demand, depending on the pace of economic activities and their daily habits of consumption, there is a different electrical demand throughout the day. Demand, in general, is minimal during the morning and it grows with the move for hours to reach peak consumption between 18:00 and 22:00, then turning to fall. It is old the idea of storing electricity produced in off-peak for its consumption in peak hours. To store large amounts of electrical power is required its conversion into some other form of energy, since it is impossible to store electrical energy as such in large quantities. One way of storing electricity is in the form of hydrogen produced by electrolysis of water which then can be stored, purified and converted into electricity through fuel cells. When there is an increase in demand for electricity, there is a need to expand the supply of energy, which means investments in generation, transmission and distribution. This work was performed a preliminary analysis of the production of electrolytic hydrogen in hours of low demand and its use in the generation of electricity in peak hours, making use of the fuel cells, so that to a certain limit value of increased electricity demand, there is no need for expansion of supply of Foz do Iguacu/PR. Moreover, at this work, the ability to harness the heat generated in fuel cells for heating water in homes was considered. (author)

  13. Synthesis and characterization of lanthanum manganite films for using in solid oxide fuel cells for operation at intermediate temperatures; Sintese e caracterizacao de filmes de manganita de lantanio para utilizacao em pilhas a combustivel de oxido solido para operacao em temperaturas intermediarias

    Energy Technology Data Exchange (ETDEWEB)

    Gama, L.M.; Paes Junior, H.R. [Laboratorio de Materiais Avancados - LAMAV - Universidade Estadual do Norte Fluminense - UENF, Campos dos Goytacazes, RJ (Brazil)

    2010-07-01

    This work aims to investigate the effects of doping and thermal processing of LaMnO{sub 3}, La{sub 0},{sub 8}Sr{sub 0},{sub 2}MnO{sub 3} e La{sub 0},{sub 8}Ca{sub 0},{sub 2}MnO{sub 3} films deposited by spray-pyrolysis technique on their structural, morphological and electrical properties, seeking its application as cathode in solid oxide fuel cells for operation in intermediate temperatures (IT-SOFC). These films were deposited on ferritic stainless steel type AISI 444. The thermal processing of the films was accomplished in air with treatment temperature of 900 degree or 1000 degree during 2 hours. The characterization by Xray diffraction revealed that the thermal processing propitiated the formation of the expected phases with the structure of perovskite. The analysis of surface morphology showed that doping provides an increase in porosity. Electrical characterization showed that Sr-doped films showed higher conductivity values and an activation energy of the conduction process of 0,41 eV. (author)

  14. Effects on the work of a direct ethanol fuel cell as function of compacting force applied to the cell; Efeitos no funcionamento de uma celula a combustivel com alimentacao direta de etanol (CCADE) em funcao da forca de compactacao aplicada a celula

    Energy Technology Data Exchange (ETDEWEB)

    Belchior, P.M.; Forte, M.M.C. [UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Serafin, R.; Fusiger, V.; Carpenter, D. [FURB - Fundacao Universidade Regional de Blumenau, SC (Brazil)

    2010-07-01

    This experiment aimed to verify the influence due to the variation of the compacting force applied to a DEFC. According to the tests, as the increase of cell compacting, the performance improves significantly. According applied tests, when the high electrical conductivity components are used, small differences of the cell compacting can generate a large difference on the total ohmic resistance. Through the tests one can conclude that with the increase of cell compacting, the contact probably increase among the distribution of reagents and the diffuser layer, improving the cell performance. (author)

  15. Taking advantage of natural gas for the energy and fuel supply for the Brazilian energy intensive industries: aluminium, siderurgy and chemical products; O aproveitamento do gas natural para o suprimento de energia e combustivel para as industrias energointensivas brasileiras: aluminio, siderurgia e produtos quimicos

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Jose Fernando Leme [Universidade Sao Paulo (USP), SP (Brazil). Programa Interunidades de Pos Graduacao em Energia]. E-mail: romero@iee.usp.br

    2006-07-01

    This work intend to analyse natural gas success in the energy generation for siderurgy industry, aluminium and basic organic chemical products. There is a necessity to inform economy-policy and the energy policy relationship, showing the Brazilian State actuation in the economic development mechanism and electric energy supply. Cast iron and iron, metals and no-irons are considered as electric intensives and energy intensives industry activities. These are sectors that produce merchandises for exportation and spend many quantities of electrical energy for each produced physical unity of law aggregate economic value. (author)

  16. Cost analysis of electrical power from an ethanol reformer and the fuel cell in the development of productive activities in the community Pico do Amor, MT, Brazil; Analise do custo da energia eletrica proveniente de um reformador de etanol e celula a combustivel no desenvolvimento de atividades produtivas na comunidade Pico do Amor/MT

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Davi Gabriel; Teixeira, Andre Frazao; Lopes, Daniel Gabriel; Cavaliero, Carla Kazue Nakao [Universidade Estadual de Campinas (DE/FEM/UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Departamento de Energia; Instituto Aqua Genesis, Campinas, SP (Brazil); Hytron, Campinas, SP (Brazil)

    2010-07-01

    This work has the objective to analyze the impact of the cost of from an ethane reformer / fuel cell in the family income considering the development of two productive activities selected by the community itself: the production and marketing of cassava flour and 'rapadura', a typical brazilian candy. The community energy demand was analyzed to achieve the results; estimated the energy cost from the implemented system and the money from the selling of the cassava flour and 'rapadura' produced with this electricity; the study of sensibility of the ethanol price in the electrical energy cost was done too, and the cassava flour and 'rapadura' in the family funds. From the results, it was verified that the electrical energy cost has a 16,4% impact in the family gross income and a net value around R$ 260,85/family, indicating that the community will have enough funds to pay for the energy and also will rise the amount of money for each family. Besides, the comparative analyze of the cost of the electricity from the ethanol/fuel cell reformer and photovoltaic systems shows that, considering only the maintenance and operation costs, the first one should be more attractive than the second one. (author)

  17. Establishment and prioritization of relevant factors to the safety of fuel cycle facilities non reactor through dynamics archetypes evaluation; Estabelecimento e priorizacao de fatores relevantes para a seguranca de instalacoes do ciclo do combustivel exceto o reator atraves da avaliacao da dinamica de arquetipos

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Anna Leticia Barbosa de

    2012-07-01

    The present work aims to establish and prioritize factors that are important to the safety of nuclear fuel cycle facilities in order to model, analyze and design safety as a physical system, employing systemic models in an innovative way. This work takes into consideration the fact that models that use adaptations of methodologies for nuclear reactors will not properly work due to the specificities of fuel cycle facilities. Based on the fundamentals of the theory of systems, the four levels of system thinking, and the relationship of eight socio technical factors, a mental model has been developed for safety management in the nuclear fuel cycle context. From this conceptual model, safety archetypes were constructed in order to identify and highlight the processes of change and decision making that allow the system to migrate to a state of loss of safety. After that, stock and flow diagrams were created so that their behavior could be assessed by the system's dynamics. The results from the analysis using the model that simulates the dynamic behavior of the variables (socio technical factors) indicated, as expected, that the system's dynamics proved to be an appropriate and efficient tool for modeling fuel cycle safety as an emergent property. (author)

  18. Life cycle assessment (LCA) methodology: importance in the integration of the fuel cell technology type PEMFC (proton exchange membrane fuel cells); Metodologia da analise de ciclo de vida: importancia na insercao da tecnologia de celula a combustivel do tipo PEMFC (membrana polimerica trocadora de protons)

    Energy Technology Data Exchange (ETDEWEB)

    Fukurozaki, Sandra Harumi; Seo, Emilia Satoshi Miyamaru [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)). Centro de Ciencia e Tecnologia de Materiais], e-mail: shfukuro@ipen.br

    2004-07-01

    To improve the standard of society's quality of life, it is necessary to improve the quality of distributed energy and its inherent services within a sustainability process. Among different technological routes that produce more sustainable energy are the fuel cells - also known as combustible batteries. The Global Environment Facility (GEF) has identified the fuel cells as a potential technology to reduce, in the future, the effect of greenhouse gases in both developed and developing countries. Although there are various types of fuel cells, the most used technology for research studies on fuel cells is the Polymer Electrolyte Fuel Cells (FEMFC). However, economic issues - related to the high cost of the membrane's materials and of the catalysts of groups of platinum metals - are still some of the obstacles that need to be overcome for this technology to be more accessible. There are also socio-environmental aspects related to the impacts caused by the extraction, the use and the destination of these metals. Taking in consideration the challenges of complying with the demands of the market and the society as well as with the growing tendency of more rigid patterns of environmental control, the objective of the present work is to show the tool of environmental management - Life Cycle Assessment (LCA) - and its importance on the pursuit for socio-economic and environmental alternatives feasible to the recycling of the catalysts of platinum of the PEMFC. This way, it intends to collaborate to the progress of the knowledge about environmental and socio-economic subjects related to the productive process of the PEMFC. (author)

  19. Thermal-hydraulic analysis of the outermost fuel plates of a MTR5 fuel element used in the IEA-R1 research reactor; Analise termo-hidraulica das placas externas de um elemento combustivel tipo placa utilizado no reator de pesquisas IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Umbehaun, Pedro Ernesto; Torres, Walmir Maximo; Andrade, Delvonei Alves de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: umbehaun@ipen.br; wmtorres@ipen.br; delvonei@ipen.br

    2004-07-01

    This work presents the thermal-hydraulic analysis for the outermost fuel plates for 5 MW reactor operation power, considering internal flow distribution experimentally measured, and by using the flow through the channels between two fuel elements, external flow. Results showed the necessity of changing the fuel element design, which was taken into account through the reduction of uranium concentration for external plates in order to guarantee its suitable cooling.

  20. Cost analysis of electrical power from an ethanol reformer and the fuel cell in the development of productive activities in the community Pico do Amor, MT, Brazil; Analise do custo da energia eletrica proveniente de um reformador de etanol e celula a combustivel no desenvolvimento de atividades produtivas na comunidade Pico do Amor/MT

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Davi Gabriel; Teixeira, Andre Frazao; Lopes, Daniel Gabriel; Cavaliero, Carla Kazue Nakao [Universidade Estadual de Campinas (DE/FEM/UNICAMP), SP (Brazil). Faculdade de Engenharia Mecanica. Departamento de Energia; Instituto Aqua Genesis, Campinas, SP (Brazil); Hytron, Campinas, SP (Brazil)

    2010-07-01

    This work has the objective to analyze the impact of the cost of from an ethane reformer / fuel cell in the family income considering the development of two productive activities selected by the community itself: the production and marketing of cassava flour and 'rapadura', a typical brazilian candy. The community energy demand was analyzed to achieve the results; estimated the energy cost from the implemented system and the money from the selling of the cassava flour and 'rapadura' produced with this electricity; the study of sensibility of the ethanol price in the electrical energy cost was done too, and the cassava flour and 'rapadura' in the family funds. From the results, it was verified that the electrical energy cost has a 16,4% impact in the family gross income and a net value around R$ 260,85/family, indicating that the community will have enough funds to pay for the energy and also will rise the amount of money for each family. Besides, the comparative analyze of the cost of the electricity from the ethanol/fuel cell reformer and photovoltaic systems shows that, considering only the maintenance and operation costs, the first one should be more attractive than the second one. (author)

  1. Preparation and characterization of PVA/SSA membranes with Al{sub 2}O{sub 3} nanoparticles for fuel cell applications; Preparacao de caracterizacao de membranas de PVAL/SSA na presenca de nanoparticulas de Al{sub 2}O{sub 3} para aplicacao em celulas de combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paula N.; Pires, Alfredo T.N. [Grupo de Estudo em Materiais Polimericos - POLIMAT - UFSC, Florianopolis, SC (Brazil); Catarino, Margarida; Brandao, Lucia; Tanaka, Alfredo; Mendes, Adelio [Faculdade de Engenharia da Universidade do Porto, Porto (Portugal)

    2011-07-01

    In the present study, PVA/SSA membranes were prepared with and without the addition of Al{sub 2}O{sub 3} nanoparticles. Sulfosuccinic acid (SSA) was used as the crosslinking agent. Membranes were prepared with different amounts of SSA (26, 43 and 55 wt.%) and with 5 and 10 wt.% of nanoparticles. Crosslinking was performed at 90 degree C during 1.5 h. Membranes were analyzed by infrared spectroscopy, thermal analysis, water absorption, ion exchange capacity (IEC) and proton conductivity. The results showed that control of the crosslinking conditions, IEC value, water absorption and polymer structure are of significant importance to obtain a set of properties suitable for application in proton exchange membrane fuel cells. (author)

  2. A geographic information system and multi criteria analysis method for site selection of spent nuclear fuel disposal; Metodologia baseada em sistemas de informacao geografica e analise multicriterio para a selecao de areas para a construcao de um repositorio para o combustivel nuclear usado

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Vivian Borges

    2009-07-01

    This thesis aims to develop a site selection methodology for the construction of final repository for the spent nuclear fuel disposal, by using geographic information systems (GIS) and multi-criteria decision analysis. Decision making processes of this kind are often complex, given the great number of space parameters to consider and also the typically conflicting opinions of the diverse stake holders. By using GIS, data from different space parameters can be quickly and reliably stored, treated and analyzed. Multi-criteria techniques allow for the incorporation of different stake holders' opinions. These tools, when jointly used, allow for the decision process to be more transparent, quick and reliable. The method developed was applied to the particular case of the state of Rio de Janeiro. Weights obtained from an expert panel and also by using the Hierarchical Analysis Method and cartographic data were combined in the GIS. The application showed that it is possible not only to select and classify areas as to their aptness for the proposed objective, but also to exclude those clearly inadequate areas, thus optimizing the selection process by reducing the search space and consequently minimizing costs and the time spent in the search. (author)

  3. Preparation of PtRu/C and PtSn/C electrocatalysts using electron beam irradiation for direct and ethanol fuel cell; Preparacao de eletrocatalisadores PtRu/C e PtSn/C utilizando feixe de eletrons para aplicacao como anodo na oxidacao direta de metanol e etanol em celulas a combustivel de baixa temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Furtunato da

    2009-07-01

    PtRu/C and PtSn/C electrocatalysts were prepared using electron beam irradiation. The metal ions were dissolved in water/2-propanol and water/ethylene glycol solutions and the carbon support was added. The resulting mixtures were irradiated under stirring. The effect of water/ethylene glycol and water/2-propanol (v/v) ratio, Pt:Ru and Pt:Sn atomic ratios, the irradiation time and dose rate were studied. The obtained materials were characterized by Energy dispersive analysis of X-rays (EDX), X-ray diffraction (XRD), cyclic voltammetry (CV) and Moessbauer spectroscopy. The electro-oxidation of methanol and ethanol were studied by cyclic voltammetry and chronoamperometry using the thin porous coating technique. The electrocatalysts were also tested on the Direct Methanol and Ethanol Fuel Cells. PtRu/C electrocatalysts prepared in water/ethylene glycol showed Pt:Ru atomic ratios different from the nominal ones. The results suggested that part of the Ru(III) ions were not reduced. The obtained materials showed the face-centered cubic (fcc) structure of Pt and Pt alloys with crystallite sizes of 2-3 nm. PtRu/C electrocatalysts prepared in water/2-propanol showed Pt:Ru atomic ratios similar to the nominal ones. The obtained materials also showed the fcc structure of platinum and platinum alloys with crystallite sizes of 3-4 nm. PtSn/C electrocatalysts prepared in water/ethylene glycol and water/2-propanol showed Pt:Sn atomic ratios similar to the nominal ones. The obtained materials showed the platinum (fcc) phase with crystallite sizes in the range of 2 - 4 nm and a SnO{sub 2} (cassiterite) phase. The obtained PtRu/C and PtSn/C electrocatalysts showed similar or superior performance for methanol and ethanol electro-oxidation compared to commercial PtRu/C (E-TEK) and PtSn/C (BASF) electrocatalysts. (author)

  4. Preparation of Pt Ru/C electrocatalysts using gamma radiation for application as anode in direct methanol fuel cell; Preparacao de eletrocatalisadores PtRu/C utilizando radiacao {gamma} para aplicacao como anodo na oxidacao direta de metanol em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Spinace, Estevam V.; Silva, Dionisio F. da; Cruz, Victor A. da; Oliveira Neto, Almir; Machado, Luci D.B.; Pino, Eddy S.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: espinace@ipen.br

    2005-07-01

    PtRu nanoparticles supported on carbon (PtRu/C electrocatalysts) were prepared submitting a water/2-propanol mixture containing the metal ions and the carbon support to gamma radiation. The water/2-propanol (v/v) and the total dose (kGy) were studied. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry. The methanol electro-oxidation was studied by cyclic voltammetry using the thin porous coating. In the studied conditions, the electrocatalytic activity of the prepared electrocatalysts depend on the water/2-propanol ratio used in the reaction medium. (author)

  5. Evaluation and application of PEMFC fuel cell's technologies developed at IPEN applied to a 500 W{sub e} fuel cell stack; Avaliacao e aplicacao de tecnologias de celulas a combustivel tipo PEMFC desenvolvida no IPEN em um modulo de 500 W{sub e} de potencia nominal

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Edgar Ferrari da

    2009-07-01

    This work is part of a research project on PEMFC technologies carried out in IPEN to develop and optimize a 500 W{sub e} fuel cell stack. The MEAs scaling up from 25 cm{sup 2} to 144 cm{sup 2} produced by the method of sieve printing; computational fluid dynamics by computer simulation of gas flow channels in bipolar plates using COMSOL{sup R} program and the use of Pt/C electrodes developed by alcohol reduction method in single cells were used to build a stack of 500 W{sub e} nominal power for possible commercial applications, produced with national technology and industrial support. A 100 hours fuel cell's test was carried out in a 144 cm{sup 2} single cell to study the stability of the MEA fabricated by sieve printing method. This single cell showed good stability within this period of time. The developed stack has reached the maximum power of 574 W{sub e} at 100 A (694.4 mA cm{sup -2}). The operating power of 500 W{sub e} was obtained at 77.7 A (540.1 mA cm{sup -2}) and potential of 6.43 V, with efficiency of 43.3%. In terms of cogeneration, the thermal power or generated heat by the stack was 652 W{sub t}. The initial estimated cost for the 500 W{sub e} stack was about R$ 4,500.00, considering only the used materials for its construction. (author)

  6. Effects of different level addition of zeolite ZSM-5 additive on quality and composition of the dry gas, LPG (Liquefied Petroleum Gas) and gasoline, produced in FCC (Fluid Catalytic Cracking); Efeito dos diferentes niveis de adicao de aditivos de ZSM-5 na qualidade e composicao do gas combustivel, GLP e gasolina produzidos em FCC

    Energy Technology Data Exchange (ETDEWEB)

    Bastiani, Raquel; Pimenta, Ricardo D.M.; Almeida, Marlon B.B.; Lau, Lam Y. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The effects of the addition of different level of ZSM-5 additives on different FCC catalysts formulations have been studied on laboratory scale FST (Fluidized Simulation Test). The main objective of the present work is to perform a qualitative identification of the main parameters of FCC catalyst which affect the ZSM-5 additives performance concerning quality and composition of Dry Gas, LPG and Gasoline. The product composition of each test was analyzed by PIANO groups separated by carbon number. The effect of ZSM-5 on products composition was evaluated. The results showed that the ZSM-5 additive cracks gasoline range olefins and isoparaffins into Dry Gas and LPG, favoring the formation of ethylene, propylene and butylenes, while the absolute yield of gasoline aromatics changes little. The aromatics fraction in gasoline, MON and RON numbers in gasoline increase. The ZSM-5 effectiveness is negatively affected by high levels of rare earth on FCC catalyst (RE-USY). Higher hydrogen transfer provides lower olefins (higher than C6) formation, which are the most reactive species for ZSM-5 cracking. (author)

  7. Development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy; Desenvolvimento e caracterizacao do combustivel nuclear tipo placa monolitico da liga U-2,5Zr-7,5Nb revestido em zircaloy

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Geraldo Correa

    2014-06-01

    The autocthonal production of nuclear fuel in Brazil for test and research reactors is restricted to MTR (Material Test Reactor) fuel type dispersion plate, using U3Si2 alloy, coated and dispersed in aluminum, developed by IPEN-SP for use in IEA-R1 reactor. Moreover, the UO{sub 2} fuel rod type for power reactors is manufactured by Rezende (RJ) with a German technology by INB under license. Currently, Brazil is performing two programs of developing reactors. Currently, Brazil is developing two reactors. One of them is the development, by CNEN, the Brazilian Multipurpose Reactor (RMB), for testing, research and radioisotope production. The other one is the development a power reactor for naval propulsion, conducted by the Brazilian Navy. This dissertation presents the development and characterization of monolithic fuel miniplate alloy U-2.5Zr-7.5Nb, coated in zircaloy (ZRY), on a laboratory scale. Due to its innovative features and properties, this fuel can be used as fuel in both test reactors, research and producing radioisotopes for power reactors as small and medium sizes. Thus, this high potential fuel can be used in domestic reactors currently under development. The development of monolithic fuel plate type is made using the technique called 'picture-frame' where a sandwich composed of a monolith alloy U-2.5Zr- 7.5Nb coupled to a frame and coated sheets of Zry is obtained. The alloy U-2.5Zr-7.5Nb was obtained by melting in an induction furnace and then was cast into rectangular ingots of graphite, thus achieving an ingot with approximate dimensions of 170 x 50 x 60 mm. The obtained ingot was hot rolled at 850 ºC, with a 50 % reduction in thickness, in order to refine the raw structure of fusion. Samples cut from the alloy U-2.5Zr-7.5Nb, with dimensions 20 x 20 x 6 mm were placed in frames and plates Zry and joined by TIG (Tungsten Inert Gas) under an atmosphere of argon, obtaining a set of 10 mm thick, 45 mm wide and 100 mm long. The sandwiches were hot rolled to achieve miniplates with a thickness of 2mm. Finally, the miniplates were cold rolled, with a total reduction of 10%, with a final thickness of 1.8 mm. The alloy U-2,5Zr-75Nb was characterized by physical and microstructural techniques Vickers microhardness, phase analysis by X-ray diffraction and microstructure by optical and scanning electron microscopy. The miniplate was characterized by physical and microstructural techniques of X-ray radiography, blistering test, bending test, analysis of metallurgical union of meat and coating spectrometric energy dispersive X-ray, microstructure by optical and scanning electron, phase analysis of the meat by X-ray and Vickers microhardness. It was possible to obtain the alloy U-2.5Zr-7.5Nb with retained γ phase and low carbon content. Miniplates obtained by hot and cold rolling process showed vii good results as colamination between core/cladding and between their coats, retention of γ phase in the alloy remained after the process. (author)

  8. Reduction of greenhouse gases emissions listed in the Kyoto Protocol by the utilization of landfill gas using solid oxide fuel cells; Reducao das emissoes de gases de efeito estufa listados no protocolo de Quioto pelo aproveitamento do gas gerado em aterros sanitarios utilizando celulas a combustivel de oxido solido. Estudo de caso do aterro municipal de Santo Andre, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Paris, Alexandre Gellert

    2007-07-01

    In the last few years, the Kyoto Protocol had been a subject very debated, at first, in a restricted niche, manly academics and professionals related to the area of climate changes. On 16th February 2005 the Kyoto Protocol entered into force and with this a lot of publicity all over the world, so today is common to hear about it at the mass communications media. The extension of the subject is broad, this work discuss the utilization of one the Kyoto's flexibility mechanisms, to contribute to financing the use of the landfill gas in the solid oxide fuel cells. Among the three mechanisms presented in the Kyoto Protocol, the clean development mechanism (CDM) in article 12, is the only one that can be implemented by non-Annex I countries, the case of Brazil. In other hand, the issue of solid waste in Brazil is critical. Even being illegal, most of the solid waste goes to uncontrolled areas in open air places 'lixoes', causing degradation of the environment and the communities around this areas, and also emission of green house gases (GHG), deregulating the global climate system. Decontaminate this areas and the construction of landfills to replace than, considering the landfill as a bioreactor, and the utilization of the biogas to generate power can improve nowadays picture that we are facing. The utilization of an innovative alternative technology as the solid oxide fuel cell (SOFC) instead the conventional technologies will be more efficient and environmentally better. Among other barriers the cost is pointed as the biggest. In this context, the SOFC is the most expensive fuel cell, so the utilization of CDM can contribute to finance the application of this technology. Scenarios were made of 250 kW, 500 kW, 1,000 kW, 5,000 kW and 10,000 kW of installed power using biogas from the Municipal Landfill of Santo Andre. The calculations of the emission factor were done ex ante and ex post according to ACM0002. Comparing the costs of the installed power studied and the calculation of the emission reduction, a potential income, the costs are superior, however, other incomes from the selling of energy and the disposal of solid waste most be taken into account in the process of decision of this type of projects. (author)

  9. Determinação de minerais em café cru Mineral determination in green coffe

    Directory of Open Access Journals (Sweden)

    Marcelo Antonio Morgano

    2002-01-01

    Full Text Available Dois métodos de preparo de amostra foram avaliados: via seca e via úmida, para a determinação e quantificação dos minerais Al, Ba, Ca, Co, Cu, Fe, K, Mg, Mn, Ni, P e Zn em café cru, empregando-se a técnica de Espectrometria de Emissão Ótica em Plasma Indutivamente Acoplado (ICP-OES. As concentrações dos minerais não diferiram significativamente ao nível de 5% (Teste F entre os dois métodos empregados. Para avaliar a exatidão dos métodos testados foi realizada a recuperação dos minerais em uma amostra de café. Os resultados obtidos pelos métodos empregando via seca e via úmida foram, respectivamente: Al = 93% e 104%; Ba = 85% e 54%; Ca = 99% e 108%; Co = 98% e 96%; Cu = 78% e 96%; Fe = 96% e 96%; K = 91% e 82%; Mg = 100% e 95%; Mn = 104% e 101%; Ni = 95% e 107%; P = 101% e 104%; Zn = 89% e 96%. O método por via seca foi empregado para a determinação dos teores de minerais em 45 amostras de café provenientes de diferentes regiões de cultivo dos Estados de São Paulo, Minas Gerais e Bahia. Os teores de minerais (em mg kg-1 encontrados nas diferentes amostras variaram entre: Al (0,612 a 32,2, Ba (1,11 a 17,6, Ca (925 a 1889, Co (0 a 1,16, Cu (6,21 a 369, Fe (23,3 a 367, K (12252 a 17205, Mg (1526 a 2059, Mn (14,2 a 60,4, Ni (0 a 44,2, P (1172 a 1826 e Zn (3,71 a 57,0. O emprego da técnica instrumental de ICP-OES e digestão da amostra por via seca mostraram-se adequados para a determinação simultânea de elementos minerais em café, uma vez que os níveis de precisão e exatidão obtidos foram satisfatórios.Two sample preparation methods for the determination of minerals from green coffee were investigated for the purpose of methodological evaluation: ashing and acid digestion. The concentrations of minerals Al, Ba, Ca, Co, Cu, Fe, K, Mg, Mn, Ni, P and Zn were evaluated by the technique of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES. The mineral contents in green coffee did not differ

  10. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS); Validacao de metodologia analitica para determinacao de mercurio total em amostras de urina para espectrometria de absorcao atomica com geracao de vapor frio (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Guilhen, Sabine Neusatz

    2009-07-01

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L{sup -1} with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10{mu}g.L{sup -1}. The obtained results fall into a range of concentration from 1,02 to 23,36{mu}g.L{sup -1}. (author)

  11. Avaliação analítica de sistemas de introdução de amostra para a determinação de elementos traço em extratos lixiviados contendo ácido acético por espectrometria de massa com plasma indutivamente acoplado

    OpenAIRE

    Gois, Jefferson Santos de

    2012-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química No Brasil, os procedimentos para a classificação dos resíduos sólidos em relação à sua toxicidade levam em consideração a solubilidade e biodisponibilidade de metais por meio de experimentos de extração utilizando soluções contendo ácido acético e hidróxido de sódio. A análise de soluções contendo compostos orgânicos e elementos de baixo potencial ...

  12. Extração por fluido supercrítico de alguns inseticidas carbamatos em amostras de batata, com determinação por HPLC/fluorescência e confirmação por HPLC/espectrometria de massas

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    Nunes Gilvanda Silva

    2002-01-01

    Full Text Available Six supercritical fluid extraction (SFE methods were tested, by varying the following operational parameters: CO2 pressure, time and temperature of extraction, type and proportion of static modifier, and Hydromatrix®/sample rate into cell. Firstly, insecticide carbamates were extracted from spiked potatoes samples (fortification level of 0,5 mg.Kg-1 by using SPE procedures, and then final extracts were analyzed HPLC/fluorescence. Good performance was observed with SFE methods that operated with values of temperature and CO2 pressure of 50 ºC and 350 bar, respectively. Best efficiency was obtained when it was used acetonitrile as a modifier (3% on the cell volume, and Hydromatrix®/sample rate of 2:1. Static time was of 1 min; total extraction time was of 35 min; dynamic extraction was performed with 15 mL of CO2, and it was used methanol (2 mL for the dissolution of the final residue. In such conditions, pesticide recoveries varied from 72 to 94%, depending on the analyzed compound. In higher extraction temperatures, a rapid degradation was observed for some compounds, such as aldicarb and carbaryl; presence of their metabolites was further confirmed by HPLC-APCI/MS in positive mode. Detection limits for chromatographic analysis varied from 0,2 to 1,3 ng.

  13. Pesticides residues in water treatment plant sludge: validation of analytical methodology using liquid chromatography coupled to Tandem mass spectrometry (LC-MS/MS); Residuos de agrotoxicos em lodo de estacao de tratamento de agua: validacao de metodologia analitica utilizando cromatografia liquida acoplada a espectrometria de massas em Tandem (LC-MS/MS)

    Energy Technology Data Exchange (ETDEWEB)

    Moracci, Luiz Fernando Soares

    2008-07-01

    The evolving scenario of Brazilian agriculture brings benefits to the population and demands technological advances to this field. Constantly, new pesticides are introduced encouraging scientific studies with the aim of determine and evaluate impacts on the population and on environment. In this work, the evaluated sample was the sludge resulted from water treatment plant located in the Vale do Ribeira, Sao Paulo, Brazil. The technique used was the reversed phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. Compounds were previously liquid extracted from the matrix. The development of the methodology demanded data processing in order to be transformed into reliable information. The processes involved concepts of validation of chemical analysis. The evaluated parameters were selectivity, linearity, range, sensitivity, accuracy, precision, limit of detection, limit of quantification and robustness. The obtained qualitative and quantitative results were statistically treated and presented. The developed and validated methodology is simple. As results, even exploring the sensitivity of the analytical technique, the work compounds were not detected in the sludge of the WTP. One can explain that these compounds can be present in a very low concentration, can be degraded under the conditions of the water treatment process or are not completely retained by the WTP. (author)

  14. Avaliação de diferentes métodos para a determinação de cobre em óleo mineral isolante por espectrometria de absorção atômica com forno de grafite

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    Luiz Fernando S. Caldas

    2014-06-01

    Full Text Available This aim of this work was to compare two methods for copper determination in insulating oils from power transformers by GFAAS. The first method was extraction induced by emulsion breaking, which determined the preconcentration of copper in an aqueous solution and exhibited a limit of quantification of 0.27 µg L-1. Also, a second method based on the direct introduction of samples into GFAAS in the form of detergent emulsions, prepared with Triton X-114 and HNO3, was investigated. In this case, the limit of quantification was 1.7 µg L-1. Seven samples of used oils were successfully analyzed by both methods.

  15. Análise de suspensões de argilas por espectrometria de emissão óptica com plasma induzido com configuração axial Clay slurries analysis using inductively coupled plasma optical emission spectrometry with axial view configuration

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    Cíntia S. Silva

    2002-12-01

    Full Text Available The goal of this study was to evaluate the feasibility of direct introduction of clay slurries in an inductively coupled plasma optical emission spectrometer with axial view configuration. Calibration was performed using a certified reference material with a mean particle size of 13 µm (IPT-42 and the analytical curve was applied for quantification of two others reference materials (IPT-28 and IPT-32 and four samples. It was demonstrated that the analytical curve thus obtained was not completely suitable for IPT-28 and samples due to different mineralogical phases determined by X-ray diffraction. After considering this effect, it was possible for most elements to obtain results in agreement with certified values or with values obtained by a conventional technique at a 95% confidence level. It was demonstrated that the ICP-OES with axial view configuration did not present any incompatibility with the direct introduction of a complex inorganic suspension.

  16. Pré-concentração de cádmio com Saccharomyces cerevisiae e determinação em águas fluviais usando espectrometria de emissão óptica com plasma indutivamente acoplado Preconcentration of cadmium with Saccharomyces cerevisiae and determination in river water using inductively coupled plasma optical emission spectrometry

    Directory of Open Access Journals (Sweden)

    Priscila Andreoli Biscaro

    2007-04-01

    Full Text Available A preconcentration method based on the use of Saccharomyces cerevisiae as sorbent material is proposed for the determination of Cd(II in river water. The solid phase extraction was performed in batch mode and the determination of the analyte in the solid phase was easily carried out by introducing a slurry of the yeast (0.0625 g / 2.5 mL directly into the ICP OES. A limit of detection of 0.11 µg L-1 and a sample throughput in the range of 4 - 54 sample h-1 were obtained. Determinations of cadmium in a certified sample and in real river water samples were in excellent agreement with the expected values.

  17. Principais substâncias responsáveis pelo aroma de mangas comerciais brasileiras identificadas por cromatografia gasosa de alta resolução/olfatometria/espectrometria de massas Aroma impact substances on commercial brazilian mangoes by HRGC-O-AEDA-MS

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    Diógenes C. Lopes

    1999-02-01

    Full Text Available Six Brazilian commercial mangoes were analysed by HRGC-O-AEDA-MS, viz., Carlota, Haden, Espada, Coração de boi, Rubi and Tommy Atkins. All them showed ethyl butanoate as the main aroma character impact compound by AEDA evaluation. The ethyl esters of 2 and 3-methylbutanoic acids are also important, the main contribution in Carlota variety being 2(S enantiomer. In Rubi variety, both 2(R enantiomer and 3-methyl isomer contributes to the caprylic fruity note observed. In four varieties, viz., Haden, Espada, Rubi and Tommy Atkins, d-3-carene showed to be the second impact aroma compound presented. In Tommy Atkins variety, a-pinene also has a significant contribution, mainly due to its (1R,5R(+-enantiomer.

  18. Validação de um método analítico rápido por CLAE-UV para determinação de cumarina em guaco (Mikania glomerata Sprengel confirmado com espectrometria de massas

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    F.C. BERTOLDI

    2016-01-01

    Full Text Available RESUMO A espécie Mikania glomerata Sprengel, popularmente conhecida no Brasil como guaco, é amplamente utilizada como expectorante para tratar doenças respiratórias e tem a sua atividade farmacológica atribuída principalmente a cumarina. Os resultados mostraram que o método apresenta linearidade de 0,05 a 0,8 mg mL-1. Ele foi considerado seletivo, exato e preciso. A proposta de um método rápido para determinação de cumarina em extratos de guaco torna-se interessante para a rotina de controle de qualidade industrial, visando à obtenção de medicamentos fitoterápicos padronizados.

  19. Identification of ftalates used as additives in the geo membrane of a la Florida reservoir through gas chromatography-mass spectrometry; Determinacion de las ftalatos utilizados como aditivos en la geomembrana de la bolsa de la florida mediante cromtografia de gases-espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Rico, G.; Pargada, L.; Aguiar, E.; Castillo, F.

    2009-07-01

    This article studies the behaviour of the plastified poly (vinyl chloride) (PVC-P) applied as synthetic geo membrane for the waterproofing of the La Florida reservoir. We show the results of the initial examen of its properties and its most significant characteristics eighteen years after being applied. Furthermore we isolate and identify the quantitative and qualitative aspects of the plasticizers used in its formula through infrared spectroscopy, gas chromatography and mass spectrometry technic. We have identified as the said plasticizers di-n-octyl phthalate, di-n-decyl phthalate and n-decyl n-octyl phthalate, and we calculate the joint average molecular weight using Wilsons equation. The results found that the geo membranes we have studied has shown an excellent behaviour along through time. (Author) 53 refs.

  20. Desenvolvimento e validação de metodologia de análise de misturas biodiesel: diesel utilizando cromatografia gasosa-espectrometria de massas Development and validation of a methodology FOR analysis of biodiesel: diesel blends using gas chromatography-mass spectrometry