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Sample records for alcool combustivel derivado

  1. 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)

  2. Activos Derivados OTC

    OpenAIRE

    Arroyo Pereiro, Miguel

    2015-01-01

    El objetivo de este trabajo es proporcionar una visión general de los mercados de derivados financieros OTC, los principales instrumentos, los participantes y algunos aspectos de su regulación. En la actualidad el mercado global de derivados ha alcanzado un gran tamaño, tras crecer exponencialmente desde 1980, convirtiéndose en una parte significativa del mundo de las finanzas globales. Muestra de ello es la contribución destacada que se otorga a los derivados OTC en la crisis financiera inte...

  3. Derivados vinculados al seguro.

    Directory of Open Access Journals (Sweden)

    De Paz Cobo, Sonia

    2003-01-01

    Full Text Available El presente trabajo tiene como objetivo la presentación de los derivados financieros como instrumentos de cobertura de los riesgos del seguro, así como de los principales proyectos que se desarrollan a través de los mismos, como por ejemplo los derivados sobre el clima. Hay que tener presente las pérdidas multimillonarias ocasionadas en casos como el de la banca Baring’s, o el de Orange County, por citar algunas, que si bien ciertos autores afirman que están en relación directa con el uso de estos productos, no podemos olvidar que los instrumentos derivados se desarrollaron con el objetivo principal de proteger al usuario de la posible volatilidad del activo subyacente. Ya en la industria aseguradora los derivados vinculados a tal actividad son instrumentos donde el pago se condiciona a la ocurrencia de su suceso de siniestro, o serie de sucesos múltiples que disparen las pérdidas. Tras el repaso efectuado y la descripción que este tipo de instrumentos puede tener en la gestión del riesgo por parte de la industria aseguradora, concluiremos con la exposición de las relaciones con el reaseguro tradicional así como una breve referencia al futuro de este tipo de instrumentos

  4. Instrumentos derivados crediticios

    OpenAIRE

    Delfiner, Miguel; Gómez, Anabela

    2011-01-01

    Los derivados crediticios constituyen una amplia gama de instrumentos financieros cuyo valor se genera por la ocurrencia de eventos crediticios. Son usualmente negociados en forma bilateral a través del mercado OTC aunque esta tendencia puede modificarse a futuro. Su volumen y complejidad experimentó un crecimiento sustancial en los últimos años, habiéndosele adjudicado un rol importante en la reciente crisis financiera originada por las hipotecas subprime; ello explica que su tratamiento reg...

  5. Towards ProAlcool II - a review of the Brazilian bioethanol programme

    International Nuclear Information System (INIS)

    Rosillo-Calle, F.; Cortez, L.A.B.

    1998-01-01

    Since the creation of the National Alcohol Programme (NAP) in 1975, commonly known as ''ProAlcool'', it has gone through a number of fluctuations reflecting Brazilian political, economic and energy priorities. In 1996-1997 over 175 Mt of sugarcane (65% of 270 Mt harvested) was converted to ethanol fuel. The ProAlcool started as a highly innovative programme, but in recent years has lost part of its technological zeal and in certain areas is becoming stagnant. This is due to a combination of reasons, e.g. unclear energy policy, high sugar prices in the international market and lower investment in ethanol production as a result of low international oil prices. A new impetus is needed to reflect changing economic and energy policy in Brazil. This paper reviews the implications for ProAlcool of the new economic policies and the possibilities for restructuring the programme to guarantee its survival as a pioneering and sustainable renewable energy source. (author)

  6. Consommation d’alcool et lignes directrices pour la consommation d’alcool à faible risque chez les adultes : une analyse transversale de l’Alberta’s Tomorrow Project

    Directory of Open Access Journals (Sweden)

    Darren R. Brenner

    2017-01-01

    Full Text Available Introduction : La consommation modérée ou élevée d’alcool constitue un facteur de risque de mortalité toutes causes confondues et de cancer. Nous disposons de données transversales grâce aux enquêtes nationales, mais jusqu'à présent aucunes données sur la consommation d’alcool en Alberta n'étaient disponibles pour une grande cohorte prospective. Notre objectif est de définir, à la lumière des lignes directrices de prévention du cancer, les niveaux de consommation d’alcool des adultes ayant pris part à l’Alberta’s Tomorrow Project. Nous avons également analysé les liens entre la consommation d’alcool et certains autres comportements à risque, en particulier à risque élevé. Méthodologie : Entre 2001 et 2009, 31 072 hommes et femmes de 35 à 69 ans ont participé à l’Alberta’s Tomorrow Project, une grande étude de cohorte provinciale. Des données concernant la consommation d’alcool dans les 12 derniers mois ont été obtenues pour 26 842 participants ayant répondu à des questionnaires autoadministrés sur la santé et sur le mode de vie. Nous avons effectué des analyses transversales sur la consommation d’alcool quotidienne et les lignes directrices de prévention du cancer en matière de consommation d’alcool en lien avec des facteurs sociodémographiques. Nous avons aussi examiné la prévalence combinée de la consommation d’alcool, du tabagisme, de l’obésité et de diverses comorbidités. Résultats : Environ 14 % des hommes et 12 % des femmes ont déclaré consommer davantage d’alcool que ce que préconisent les recommandations en matière de prévention du cancer. Une consommation plus importante d’alcool a été rapportée chez les plus jeunes, les citadins, les personnes à revenu plus élevé et celles consommant davantage de viande rouge. En outre, le volume de consommation quotidienne d’alcool était positivement associé au tabagisme, tant chez les hommes que chez les femmes

  7. 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.

  8. 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)

  9. Metrological evaluation of petroleum, his derivatives, natural gas and alcohol flow computers; Avaliacao metrologica de computadores de vazao de petroleo, seus derivados, gas natural e alcool

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, A.F.; Callegario, E. [Pontificia Univ. Catolica do Rio de Janeiro (PUC/Rio), RJ (Brazil)], Emails: afo@puc-rio.br, callegario@puc-rio.br; Ferreira, A.; Pinheiro, J.A.; Oliveira, T.B.V. [PETROBRAS, Rio de Janeiro, RJ (Brazil)], Emails: andref@petrobras.com.br, jose.pinheiro@petrobras.com.br, thiagovidal@petrobras.com.br

    2009-07-01

    This work presents results of petroleum flow computers, his derivatives, natural gas and alcohol, used on fiscal measurements, appropriation and custodial transfer system. It is intended that the used proceed give subsides for the model approval and verify initially the flow computers, besides the periodic verification of installed flow computers. The test procedures are focused at the algorithm deviations, at the A/D (analog - digital) and D/D (digital-digital)conversion deviations, simulating static pressure transmitters, pressure differential, temperature, specific mass, BSW (Basic Sediment and Waste), and at the pulse counting deviations of the flow computer. The presented methodology is based on specific document for certification and initial verification of flow computers for the WELMEC (European Cooperation in Legal Metrology), and improved to attend the measurement requirements in Brazil. The test show various no conformities among the performance of tested flow computers compared with allowed values by the developed procedure.

  10. Perspectivas del Mercado de Derivados en Colombia Retraso derivado del desconocimiento Perspectivas del Mercado de Derivados en Colombia Retraso derivado del desconocimiento

    Directory of Open Access Journals (Sweden)

    Natalia Cañas Arboleda

    2006-12-01

    Full Text Available El mercado de derivados representa la evolución de los mercados financieros enel mundo, debido a la capacidad que tiene el primero de ofrecer cobertura a losparticipantes del mercado, función importante en el actual contexto de globalización.Por lo anterior, en el país se desarrollan, aunque un poco tarde, diversos proyectospara la incorporación de futuros y opciones, como nuevas alternativas de inversióny financiación que redunden en menor incertidumbre para los inversionistas dediferentes sectores de la economía. A partir de allí, se muestra la situación actualdel mercado de derivados en Colombia y los esfuerzos realizados por diferentesinstituciones, encaminados al desarrollo del mismo.The derivative market represents the evolution of financial markets in the world, given the capacity that the former has for offering coverage to market participants, which is an important feature in the present context of globalization. For this reason, some projects are being developed in our country, though  a bit late, for the incorporation of futures and options, as new investment and financing alternatives, which may result in a reduced uncertainty for the investors in different sectors of the economy. This article shows the current situation of the derivative market in Colombia and the efforts made by different institutions, aimed at the development of such a market.

  11. Valoración de derivados financieros: las opciones europeas

    OpenAIRE

    Ojos Araúzo, Pablo de los

    2016-01-01

    Desde la publicación de los trabajos de Black-Scholes y de Merton en 1973, la valoración de derivados financieros ha cobrado una importancia capital en el mundo de las inversiones, habiéndose desarrollado desde entonces una extensa literatura sobre el tema. En paralelo, el comercio con derivados financieros ha aumentado exponencialmente en todos los mercados financieros, estando estrechamente relacionado con la reciente crisis financiera. Por tanto, en este trabajo estudiamo...

  12. Derivados de pirazol bivalentes como inhibidores de ingesta

    OpenAIRE

    Rodríguez de Fonseca, Fernando; Jagerovic, Nadine; Fernández Fernández, Cristina; Bermúdez-Silva, Francisco Javier; Goya, Pilar

    2011-01-01

    Derivados de pirazol bivalentes como inhibidores de ingesta. Nuevos derivados alquílicos y cicloalquílicos disustituidos por pirazol-3-carboxamidas, así como su procedimiento de obtención. Estos compuestos presentan propiedades, entre otras, para la inducción de saciedad y control de la ingesta, modulación de la grasa corporal y regulación del metabolismo lipídico.

  13. Upper nozzle welding development transfer of Angra 2/00 fuel element to F.E.C. (Fabrica de Elemento Combustivel)

    International Nuclear Information System (INIS)

    Lorenzo, R.F. di; Almeida, R.C.

    1985-01-01

    The technology development of upper nozzle welding of Angra-2 Combustible element, done at CDTN (Centro de Desenvolvimento da Tecnologia Nuclear), this technology transfer to FEC (Fabrica de Elemento Combustivel), the welders training of FEC in nozzle welding, the radiographic control of nozzle welds and the FEC personnel training in this nozzle welds radiography are presented is this report. (C.M.) [pt

  14. Évaluation des politiques de lutte contre l'usage nocif de l'alcool au ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    À l'échelle mondiale, l'alcool est le troisième facteur de risque associé à la charge de morbidité. Sa consommation abusive a eu des effets considérables sur la morbidité, la mortalité et les coûts de la santé en Amérique du Sud et dans les Caraïbes. Ce projet vise à éclairer les responsables des politiques de deux pays qui ...

  15. La responsabilidad en la venta de derivados financieros

    Directory of Open Access Journals (Sweden)

    José Leonardo González-Bahamón

    2010-03-01

    Full Text Available Los vendedores de derivados financieros normalmente tienen una mayor capacidad de entendimiento en comparación con los compradores y, por lo tanto, se encuentran en una posición de superioridad para comprender totalmente las implicaciones de los productos que ofrecen, sobre todo en relación con derivados exó- ticos y estructurados negociados en el mercado OTC. Consecuentemente, existe una necesidad de protección en favor de los usuarios finales de derivados financieros. Sin embargo, cómo la mayoría de las transacciones en el mercado OTC son llevadas a cabo entre profesionales, las cortes han sido renuentes para reconocer cualquier deber legal de asesoramiento en cabeza de los vendedores expertos que pueda generar responsabilidad civil,  basándose en el argumento consistente en que los deberes fiduciarios rara vez surgen entre profesionales. En los años noventas, Banker Trust (BT, uno de los principales vendedores de derivados financieros se vio implicado en múltiples litigios con compradores en Inglaterra y EE.UU, quienes formularon pretensiones similares basadas en los conceptos legales de derecho anglosajón denominados “undue influence” (influencia indebida, misrepresentations (enunciados falsos o engañosos y la supuesta violación de un pretendido deber legal de asesoramiento en cabeza de BT. El presente artículo analiza las anteriores pretensiones en relación con el principal caso decidido en Inglaterra sobre la responsabilidad en la venta de derivados financieros (Bankers Trust International PLC v PT Dharmala Sakti Sejahtera, al igual que evalúa algunos de los conceptos legales relevantes en esta materia bajo el ordenamiento legal Colombiano.

  16. Los derivados financieros desde una perspectiva jurídica

    OpenAIRE

    Cuartas Gómez, Lucas; Sierra Vásquez, Paula

    2008-01-01

    El importante aumento en el uso de los contratos de derivados en Colombia1 y el mundo, además de la dificultad que puede traer su comprensión, nos ha llevado a escribir el presente trabajo, con el fin de darle a el lector una perspectiva general sobre el funcionamiento de estos instrumentos financieros, su regulación en Colombia y la forma como éstos se han venido contratando a nivel internacional.

  17. 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)

  18. The environmental performance of three alcohol fuel plants producers of small, medium and big scale; O desempenho eco-ambiental de tres usinas produtoras de alcool combustivel de pequeno, medio e grande porte

    Energy Technology Data Exchange (ETDEWEB)

    Borrero, Manuel Antonio Valdes; Pereira, Jose Tomaz Vieira [Universidade Estadual de Campinas, SP (Brazil); Miranda, Evaristo Eduardo de [Empresa Brasileira de Pesquisa Agropecuaria, Campinas, SP (Brazil). Nucleo de Monitoramento Ambiental e de Recursos Naturais por Satelite

    1999-07-01

    The article discusses the following issues of alcohol fuel plants producers: sizing; performance; natural resources; environmental aspects; and electric power generation. The environmental performance concept is introduced and a performance evaluation methodology are presented and applied. The results are also presented and criticized.

  19. Los instrumentos financieros derivados en el emporio textil de Gamarra 2014

    OpenAIRE

    Ortiz Guillén, Mirtha Patricia

    2015-01-01

    El presente trabajo de investigación titulado: “Los instrumentos financieros derivados en el emporio textil de Gamarra 2014”, representa un aporte a la comunidad académica y exportadora peruana porque recoge información respecto a tres aspectos importantes: el grado de conocimiento del exportador textil de Gamarra sobre los instrumentos financieros derivados, los instrumentos financieros derivados que pueden utilizar los exportadores para reducir pérdidas por tipo de cambio,...

  20. Uso de derivados de quinazollnas y sus composiciones farmacéuticas en enfermedades neurodegenerativas

    OpenAIRE

    Martínez, Ana; Redondo, Miriam; Sanz-SanCristóbal, Marina; Gil, Carmen; Morales-García, José A.; Pérez Castillo, Ana; Pérez Martín, María Concepción

    2009-01-01

    Uso de derivados de quinazolinas y sus composiciones farmacéuticas en enfermedades neurodegenerativas. La invención se refiere a derivados heterocíclicos de quinazolinas y a su potencial para el tratamiento de enfermedades neurodegenerativas y/o neurológicas, entre otras la enfermedad de Parkinson, enfermedad de Alzheimer o esclerosis. Además, la invención se refiere a composiciones farmacéuticas que comprenden dichos compuestos derivados de quinazolinas.

  1. Proceso de obtención de derivados de azetidinas

    OpenAIRE

    Boto, Alicia; Gallardo, Juan Antonio; Álvarez, Eleuterio

    2010-01-01

    Procedimiento de obtención de derivados de azetidinas. La presente invención se refiere a un procedimiento de síntesis de azetidina basado en reacciones de escisión radicalarias, que es más sencillo y directo que los métodos utilizados habitualmente. En dicho procedimiento se hace reaccionar un compuesto que contiene un alquilo C2 sustituido o sin sustituir, con un nucleófilo que contiene un grupo -CH=CH-Z, donde Z puede ser arilo o heteroarilo.

  2. La auditoría de los instrumentos financieros derivados

    Directory of Open Access Journals (Sweden)

    Vernor Mesén Figueroa

    2010-10-01

    Full Text Available El tema de los derivados ha tomado gran relevancia en Costa Rica durante los últimos años, principalmente como consecuencia de la adopción del sistema de bandas para definir el tipo de cambio. Por tratarse de un producto nuevo y de mayor sofisticación es importante dar a conocer los estándares internacionales definidos en materia contable y consecuentemente a nivel de auditoría, siendo este último el objetivo de este artículo. La Norma Internacional de Auditoría 1012 "Auditoría de Instrumentos Financieros Derivados", estipula los procedimientos que se deben tomar en cuenta para determinar la razonabilidad de los instrumentos financieros pertenecientes a una empresa. El presente artículo analiza en forma detallada cada uno de estos procedimientos, con el fin de que los profesionales de auditoría que enfrentan el reto de auditar estos nuevos productos cuenten con una base teórica actualizada para llevar a cabo sus labores en forma adecuada y de acuerdo con los estándares internacionales.

  3. 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)

  4. Production of Methanol-Higher Alcohol Mixtures from Natural Gas via Syngas Chemistry Production de mélanges méthanol-alcools supérieurs à partir du gaz, via (CO + H2

    Directory of Open Access Journals (Sweden)

    Courty P.

    2006-11-01

    Full Text Available Despite the prevailing position of ethers (MTBE, TAME as octane boosters, and the low oil prices at present, alcohol synthesis remains one of the near future means of natural gas upgrading via syngas chemistry. After a review of the available process development data in the field, this paper focuses on the IFP process studies, based on the CuCo and CuNi catalysts developed by Institut Français du Pétrole (IFR, France and Idemitsu Kosan (Japan. The adequacy between the product specifications, and the optimization of the performances is then discussed in a technico-economic context, together with a presentation of lab scale, pilot scale and demonstration scale test results. As a conclusion, a prospective overall view brings together todays economics and some improvement guidelines dealing with investments, operating cost and catalyst performances. Cette publication présente les travaux de R & D (Recherche et Développement menés par l'Institut Français du Pétrole (IFP, France et Idemitsu Kosan (Japon en synthèse d'alcools. Elle situe les résultats dans le contexte technique et économique actuel. L'accroissement constant des ressources prouvées en gaz et, chronologiquement, les deux crises pétrolières, la suppression du plomb dans les essences, ont conduit le monde industriel à intensifier les recherches concernant la synthèse d'alcools. Très récemment, les effets bénéfiques de l'addition d'alcools sur les émissions de polluants ont été mis en évidence. Toutefois, l'additivation de carburants par les alcools est en voie de disparition au profit des éthers, alors que, indépendamment, les procédés de production d'ammoniac, de méthanol, d'acide acétique, également fondés sur le gaz, se sont seuls développés. La synthèse d'alcools a fait l'objet de nombreux travaux, résumés dans les tableaux 1 et 2. L'étude des différents aspects réactionnels amène à prendre en compte l'exothermicité importante des r

  5. Dosage direct des alcools dans les carburols par chromatographie en phase gazeuse Direct Gas Chromatographie Determination of Alcohols in Gasolines Blended by Oxygenated Compounds

    Directory of Open Access Journals (Sweden)

    Petroff N.

    2006-11-01

    Full Text Available Dans cette étude, on décrit une méthode de chromatographie en phase gazeuse utilisant une colonne remplie ; elle permet de doser, sans préfractionnement, les alcools jusqu'aux butanols dans les carburols (carburants additionnés de composés oxygénés. La phase stationnaire sélectionnée est le glycérol. This report describes a gas chromatographie method using a packed column. It allows the direct determination of alcohols up to butanols in gasolines blended with oxygenated compounds without prefractionation. Glycerol has been selected as stationary phase.

  6. Estudios fisicoqu??micos y biol??gicos de un nuevo derivado de la eritromicina: el folato de eritromicina

    OpenAIRE

    Manna, P.K.; Kumaran, V.; Mohanta, G.P.

    2005-01-01

    Se prepar?? un derivado nuevo de la eritromicina, el folato de eritromicina, y se evaluaron sus propiedades fisicoqu??micas y biol??gicas. El derivado presenta una buena solubilidad en metanol, etanol y propileno glicol. Los valores de los coeficientes de partici??n, que fueron 1,12 y 1,10 en sistemas de cloroformo/agua y octanol/agua respectivamente, indican que probablemente se distribuya bien in vivo. La potencia in vitro del derivado, 716 ??g/mg, es mayor que la de derivados e...

  7. La crisis financiera global de los noventa bajo la sombra de los derivados financieros

    OpenAIRE

    Ayca Sarialioglu - Hayali

    2010-01-01

    El objetivo de este artículo es analizar el papel de los instrumentos financieros derivados en las crisis financieras internacionales del mundo en desarrollo en los noventa, tales como la crisis del sureste de Asia en 1997 y la crisis brasileña en 1999, etc. Al respecto, este artículo analiza el papel de los derivados financieros en las crisis internacionales, en términos de los efectos directos de crisis como el elemento principal para crear vulnerabilidad y disparar una masiva y rápida sali...

  8. Conflictos éticos derivados de cuidar a pacientes drogodependientes

    Directory of Open Access Journals (Sweden)

    Chinea González, Mª del Carmen

    2012-04-01

    Full Text Available Resumen: Antecedentes: La drogodependencia se puede asociar a aspectos como los efectos propios del consumo y la drogadicción, aspectos sanitarios (comorbilidad física y psiquiátrica, aspectos jurídicos y sociales.Objetivo: Conocer las herramientas que utilizan las enfermeras para afrontar posibles conflictos éticos derivados de cuidar a pacientes drogodependientes.Metodología: Se conformaron dos grupos de enfermeras: uno en atención especializada (7 enfermeras, en concreto en una Unidad de Desintoxicación Hospitalaria; y otro en atención primaria (12 enfermeras. Se realizaron sesiones en las que las enfermeras expresaron sus experiencias, ideas, sentimientos y estrategias ante la relación-cuidado de pacientes drogodependientes.Resultados: Existen aspectos importantes para las enfermeras que influyen en la aparición de conflictos éticos en la atención de drogodependencias como son la comunicación entre el Equipo; deliberación y consenso en la toma de decisiones; la formación especializada y experiencia del personal; descripción de “paciente difícil”; conceptos en la relación clínica de asertividad, receptividad, empatía, interrelación; aparición de sentimientos de impotencia y conflicto de valores; y desconocimiento de la red especializada de atención a las drogodependencias.Conclusiones: La formación en aspectos éticos relacionados con la atención a drogodependientes facilita la interrelación y la consecución de los objetivos terapéuticos, haciendo que las enfermeras y equipos sanitarios desarrollen herramientas de abordaje adecuado para situaciones que se presenten ante este tipo de pacientes. Abstract: Background: Drug dependence can be associated with aspects such as effects from drug consumption and addiction, health issues (physical and psychiatric comorbidity, legal and social aspects.Objective: To know the tools used by nurses to deal with ethical conflicts arising from drug dependant patients´ care

  9. FLAVONOIDES AISLADOS DE LAS INFLORESCENCIAS DE Piper hispidum Kunth (PIPERACEAE Y DERIVADOS ACETILADOS

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    Luis Enrique Cuca

    2009-04-01

    Full Text Available A partir del extracto etanólico de las inflorescencias de la especie Piper hispidum Kunth (Piperaceae fueron aislados tres flavonoides: 5-hidroxi-7-metoxiflavanona, 5-hidroxi-4’,7-dimetoxiflavanona y 2’,4’,6’-trimetoxidihidrochalcona. De las flavanonas aisladas fueron obtenidos los  derivados acetilados: 5-acetoxi-7-metoxiflavanona y  5-acetoxi-4’,7-dimetoxiflavanona. Las estructuras fueron elucidadas empleando técnicas espectroscópicas y por comparación con datos de literatura. Los compuestos naturales y sus derivados fueron sometidos al bioensayo de letalidad frente a Artemia salina. El flavonoide 5-hidroxi-7-metoxiflavanona presenta la mayor actividad tóxica frente a los microcrustaceos CL50 1.8 µg/ml.

  10. La crisis financiera global de los noventa bajo la sombra de los derivados financieros

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    Ayca Sarialioglu - Hayali

    2010-05-01

    Full Text Available El objetivo de este artículo es analizar el papel de los instrumentos financieros derivados en las crisis financieras internacionales del mundo en desarrollo en los noventa, tales como la crisis del sureste de Asia en 1997 y la crisis brasileña en 1999, etc. Al respecto, este artículo analiza el papel de los derivados financieros en las crisis internacionales, en términos de los efectos directos de crisis como el elemento principal para crear vulnerabilidad y disparar una masiva y rápida salida de capitales y efectos indirectos como acelerador de la crisis por el uso de algunos tipos específicos de derivados, como los total return swaps, los put-able debt, etc. La presencia de mercados de derivados pobremente e inapropia-damente estructurados, como los existentes en las economías en desarrollo en los noventa, estos han sido creados para ser usados con propósitos económicamente nocivos, han sido usados para tomar altos riesgos y escapar de las regulaciones prudenciales. Se sostiene que, aunque ellos fueron inicialmente diseñados para contribuir a la estabilidad financiera en virtud de sus potenciales beneficios económicos, tales como desplazamiento del riesgo y descubrimiento de precio, especialmente en los países en desarrollo, han causado inestabilidad financiera y fallas de mercado, riesgo moral y selección adversa, que son la raíz de los problemas de información asimétrica comúnmente vistos en los mercados financieros. Además han sido ampliamente usados para propósitos especulativos.

  11. REVISIÓN: INULINA EN ALGUNOS DERIVADOS CÁRNICOS INULINA IN MEAT FOODS: A REVIEW

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    Segundo Álvaro Muñoz Ohmen

    2012-06-01

    Full Text Available Resumen. Se presenta una revisión bibliográfica sobre las características físicas y químicas de la inulina, su capacidad para la formación de gel y el uso en algunos derivados cárnicos. La inulina ha sido objeto de investigaciones en la ciencia y tecnología de cárnicos, como componente para reemplazar parte de la grasa, también para lograr reducir los valores de densidad energética y como mejorador de las propiedades texturales en derivados cárnicos como salchichas y mortadelas. Su uso en este tipo de derivados ha logrado generar efectos positivos en las propiedades sensoriales, pero también puede causar reducción de la intensidad de algunas de ellas. De acuerdo con el estado del arte, no ha sido estudiada la incorporación de inulina en derivados cárnicos no emulsionados, por lo cual sería interesante realizar investigaciones sobre la inclusión de inulina en derivados cárnicos de músculo entero de res, cerdo o pollo.Abstract. This document presents a literature review on the physical and chemical characteristics of inulin and its ability to gel formation, as well as the use in some meat products. Inulin has been investigated in meat science and technology as a component to replace some of the fat; also to reduce the energy density values, and as textural properties improver in meat products, such as sausage cold cuts. Its use in this type of derivatives has generated positive effects on the sensory properties, but can also lead to reduction in the intensity of some of them. According to the bibliography has not been studied the incorporation of inulin in other meat products, so it would be interesting to conduct more research on the inclusion of inulin in whole muscles of meat, pork or poultry.

  12. Production de méthanol et d'alcools supérieurs à partir de gaz via (CO + H2 Production of Methanol and Higher Alcohols from Gas via (Co + H2

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    Kawata N.

    2006-11-01

    Full Text Available Dans le cadre des procédés en développement pour la synthèse d'alcools à partir de syngas (CO + H2, ce mémoire présente certains résultats récents de l'Institut Français du Pétrole (IFP (France et Idemitsu Kosan (Japon. La première démonstration du procédé, sous programme R et D du RAPAD-Japon, a confirmé les performances et la faisabilité. Les alcools sélectivement produits, après fractionnement, présentent de bonnes propriétés pour l'usage carburant. L'optimisation de l'ensemble constitué par la production du syngas, la synthèse, le fractionnement des alcools, a permis une simplification sensible du procédé, une optimisation spécifique des performances, ce qui conduit à des données économiques plus favorables. Within the framework of processes being developed for alcohol synthesis from syngas, this article describes some recent results obtained by Idemitsu-Kosan (Japan and Institut Français du Pétrole (IFP (France. The first demonstration of the process as part of the RAPAD-Japan R & D program has confirmed both its performances and feasibility. The alcohols selectively produced, after suitable fractionation, present good properties as a blend for motor fuels. The optimization of the overall process for syngas production, alcohol synthesis and alcohol fractionation has led to a significant simplification of the process and to the optimization of its performances, leading to better economics.

  13. Experience de conduite, alcool et environnement monotone. In Sandrine Gaymard et Teodor Tiplica (Eds.) Sécurité routière : un défi à l'aube du XXIème siècle

    OpenAIRE

    BERTHELON, Catherine; GALY, Edith

    2017-01-01

    L'hypothèse est faite que la prise d'une faible dose d'alcool en début d'après-midi, au moment de la baisse physiologique du niveau de vigilance (creux post prandial), pourrait entraîner un assoupissement précoce, notamment chez les jeunes conducteurs novices, ayant des répercussions sur la performance. La baisse de performance devrait s'amplifier au fur et à mesure de la conduite, de par la monotonie et la longueur de la séance de conduite. Seize jeunes conducteurs de 18 ans venant d'obtenir...

  14. Modelo Vectorial para la Inferencia del Estado Cognitivo de Pacientes en Estados Derivados del Coma

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    Esteban Velásquez R.

    2014-06-01

    Full Text Available La forma tradicional de evaluar el estado de conciencia de un individuo, ha sido mediante la aplicación de estímulos y el análisis de sus respuestas, sin embargo, esta técnica se ve limitada cuando el individuo es incapaz de responder evidentemente ante un estímulo, como es el caso de los pacientes en estados derivados del coma. En estos casos, se requiere de una conexión directa con el cerebro del paciente para detectar una respuesta. Por consiguiente, en este artículo se desarrolla y analiza un modelo computacional basado en los principios de las máquinas de soporte vectorial (MSV, para inferir el estado cognitivo de pacientes en estados derivados del coma, mediante la utilización de un equipo de electroencefalografía comercial. Los resultados obtenidos, mostraron que el modelo logró clasificar correctamente una tarea cognitiva en al menos cuatro de cada cinco pruebas en pacientes de control, lo que se traduce en la obtención de un sistema de bajo costo para el análisis del estado de conciencia y para la posible comunicación con algunos pacientes en estados derivados del coma mediante protocolos médicos definidos. De esta manera, este sistema se presenta como un gran aporte para las clínicas y centros hospitalarios, como herramienta potencial de diagnóstico para este tipo de pacientes.

  15. Virulencia de cepas de Listeria monocytogenes procedentes de cabras y sus derivados

    OpenAIRE

    Guicela Ramírez Bernal; Alma Virginia Lara Sagahón; Carlos Gerardo García Tovar; Efrén Díaz Aparicio; Víctor Rubén Tenorio Gutiérrez

    2014-01-01

    Se evaluó la virulencia de cepas de Listeria monocytogenes todas de serotipo 4b procedentes de cabras y sus derivados. Se observaron niveles de virulencia variables cuando se comparó la virulencia relativa (porcentaje de letalidad) en ratones BALB/c inoculados vía intravenosa o intragástrica y su capacidad para infectar macrófagos J774A.1, y células epiteliales Caco-2. Dos cepas obtenidas de alimento de cabras produjeron 100 % de letalidad por ambas vías de inoculación y no mostraron diferenc...

  16. Síntesis de nuevos antioxidantes derivados del hidroxitirosol. Interacción con ciclodextrinas

    OpenAIRE

    Marset Castro, Azucena

    2014-01-01

    Tesis descargada desde TESEO En la presente Tesis Doctoral se ha llevado a cabo la preparación de derivados funcionales del hidroxitirosol (HT), con objeto de obtener nuevos polifenoles bioactivos de interés en el ámbito de los alimentos funcionales, cosmética o industria farmacéutica. En primer lugar se describe la conversión del HT en ésteres alifáticos de cadena variable; en este contexto, se ha abordado la transesterificación quimioselectiva del hidroxilo alifático del hidroxitirosol c...

  17. Modelos de crisis y el uso de los instrumentos financieros derivados

    OpenAIRE

    Roberto Soto Esquivel; Eugenia Correa Vázquez

    2008-01-01

    Con el rompimiento de Bretton Woods, los mercados financieros se han vuelto más inestables y volátiles, lo que ha provocado escenarios de crisis más recurrentes, cada vez más profundas. Los teóricos ortodoxos han buscado predecir este tipo de crisis por medio de los llamados modelos de primera, segunda y tercera generación, pero están carentes del planteamiento, del análisis y de la interpretación de los instrumentos financieros derivados, los cuales pueden modificar el comportamiento de las ...

  18. EL PROBLEMA DE LA HIDROFILICIDAD EN MATERIALES PLÁSTICOS DERIVADOS DE ALMIDÓN

    OpenAIRE

    CERON M., ALCY RENE

    2013-01-01

    El almidón es un polisacárido natural renovable, económico y a partir del cual se pueden obtener fácilmente productos plásticos biodegradables. Sin embargo, los productos obtenidos a partir de almidón presentan bajas propiedades mecánicas y tienden a cambiar sus propiedades en presencia de agua. Para disminuir los problemas provocados por el agua en los productos plásticos derivados de almidón, causados por la alta hidrofilicidad de este polímero, se han planteado diversas estrategias tales c...

  19. O medicamento proibido : como um derivado da maconha foi regulamentado no Brasil

    OpenAIRE

    Monique Batista de Oliveira

    2016-01-01

    Resumo: Este trabalho investiga de que modo o canabidiol (CBD), um dos compostos da cannabis sativa, tomou a mídia, a agenda de agências reguladoras e passou a ser reconhecido pelo seu potencial terapêutico no Brasil no espaço de um ano (de março de 2014 a janeiro de 2015). A pesquisa, mais precisamente, elucida como um deriva-do da maconha foi regulamentado sem que a própria maconha fosse objeto de regulamentação. Para isso, a dissertação acompanha o caso de Anny Fischer, que utilizou o CBD ...

  20. Instrumentos financieros del mercado de derivados que se manejan en México

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    Cristina Pacheco Ornelas

    2016-02-01

    Full Text Available Las operaciones de comercio internacional, de las que se derivan la movilidad de capitales, intensifican el riesgo de los empresarios inversionistas. En este trabajo se señala la forma para administrar el riesgo; también se presenta un breve bosquejo del marco legal que regula las relaciones entre los presentadores y usuarios de los servicios financieros, así como una breve descripción de los instrumentos financieros que se manejan en el mercado mexicano de derivados y el comportamiento registrado en la demanda de estos servicios.

  1. Efectos secundarios derivados del consumo de esteroides anabólicos en el deportista.

    OpenAIRE

    Hernández Fernández, Sergio

    2016-01-01

    Los esteroides anabólicos androgénicos son análogos sintéticos químicamente modificados de la testosterona. Desde su descubrimiento, a principios del siglo XX, su uso se ha extendido enormemente en el deporte profesional, y de forma más preocupante, en los adolescentes y adultos jóvenes. La realización de este trabajo se justifica por la necesidad de conocer de forma exhaustiva los efectos secundarios derivados del consumo de esteroides anabólicos ante el problema de salud pública que represe...

  2. Mercado consumidor de carne suína e derivados em Belo Horizonte

    OpenAIRE

    Faria,I.G.; Ferreira,J.M.; Garcia,S.K.

    2006-01-01

    Avaliou-se o comportamento do mercado consumidor de carne suína e seus derivados em Belo Horizonte. Foram entrevistados 401 consumidores, homens e mulheres, maiores de 19 anos de idade, mantendo-se a proporcionalidade observada no censo populacional. Além de sexo e faixa etária, escolaridade, ocupação e renda familiar foram levantadas para compor os fatores condicionantes da pesquisa. A carne suína in natura é consumida até três vezes por semana pela maioria da população (61,6%), em função de...

  3. Contenu énergétique des alcools d'origine fossile ou biomasse Energy Content of Alcohols of Fossil Or Biomass Origin

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    Arlie J. P.

    2006-11-01

    Full Text Available En utilisant une méthode basée sur le contenu énergétique, défini comme étant la quantité d'énergie mise en oeuvre dans le processus de fabrication depuis la matière première jsuqu'au produit considéré, on compare les filières de production basées sur des matières premières soit d'origine fossile, soit d'origine biomasse. Ces filières peuvent être utilisées pour produire les divers alcools que sont le méthanol, l'éthanol et le butanol. II est montré, qu'en l'état actuel des technologies de fabrication, la comparaison énergétique est très en faveur de la filière matière première renouvelable qui fait apparaître un gain énergétique qui varie suivant les cas étudiés entre 0,1 et 1,5 tep par tonne de produit. Production routes based on raw materials from either fossil or biomass origin are compared using a method based on the energy content, which is defined as being the amount of energy implemented in the manufacturing process starting with the raw material and going to the product being considered. These routes can be used to produce different alcohols such as methanol, ethanol and butanol. Given the current state of manufacturing technologies, this article shows that an energy comparison is highly in favor of the renewable raw-material route which shows an energy gain that varies, according to the cases examined, between 0. 1 and 1. 5 tOE per ton of product.

  4. EL PROBLEMA DE LA HIDROFILICIDAD EN MATERIALES PLÁSTICOS DERIVADOS DE ALMIDÓN

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    ALCY RENE CERON M.

    Full Text Available El almidón es un polisacárido natural renovable, económico y a partir del cual se pueden obtener fácilmente productos plásticos biodegradables. Sin embargo, los productos obtenidos a partir de almidón presentan bajas propiedades mecánicas y tienden a cambiar sus propiedades en presencia de agua. Para disminuir los problemas provocados por el agua en los productos plásticos derivados de almidón, causados por la alta hidrofilicidad de este polímero, se han planteado diversas estrategias tales como la modificación química del almidón, la asociación del almidón con otros polímeros menos hidrofílicos y la modificación superficial de los productos finales. En la presente revisión se presentan ejemplos de trabajos investigativos relacionados con cada una de las estrategias mencionadas, centrando la atención en la modificación superficial, que permite disminuir con efectividad la hidrofilicidad de los productos derivados de almidón sin afectar apreciablemente las características internas del material.

  5. Análisis sobre la factibilidad de implementar un producto de derivados sobre gas natural en Colombia

    OpenAIRE

    Dowd Aguirre, Jessica Alexandra; Tirado Naranjo, Lina María

    2012-01-01

    El objetivo de este trabajo es realizar un análisis sobre la factibilidad de implementar un producto de derivados sobre gas natural en Colombia dado el desarrollo del sector y la importancia de este hidrocarburo como fuente alternativa de generación eléctrica. 73 p. Contenido parcial: Situación actual del mercado de gas natural colombiano -- Expectativas del mercado de gas natural colombiano -- Mercados de derivados sobre gas natural en Europa y Estados Unidos -- Mercado de gas natural ...

  6. 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.

  7. Reduction by metals dissolved in liquid ammonia of keto steroids. Equilibration of the alcohols; Reduction par les metaux dissous dans l'ammoniac liquide de cetones en serie steroide. Equilibration des alcools

    Energy Technology Data Exchange (ETDEWEB)

    Giroud, A M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    'une cetone par les metaux en dissolution fait intervenir deux electrons: on peut considerer comme intermediaire un radical-anion, puis un dianion ou un carbanion. Le radical-anion pouvant aussi se dimeriser pour donner des pinacols. Pour interpreter les resultats des reductions, il nous fallait connaitre les stabilites relatives des alcools ce qui nous a conduit a faire des equilibrations. Dans un premier chapitre, nous etudions les methodes de preparation de l'androstanone-ll et des androstanols-ll{alpha} et ll{beta}. Nous verifions ensuite qu'il n'est pas possible selon nos methodes de conclure sur la stabilite relative des deux alcools par equilibrations experimentales. Nous decrivons enfin les methodes de reduction de la cetone par les metaux alcalins et alcalino-terreux dissous dans l'ammoniac liquide, suivant deux procedes: soit en presence de donneur de protons, soit avec addition posterieure de donneur de protons. Ces reductions conduisent a un melange des deux alcools ou l'isomere {alpha} equatorial stable predomine. Dans un deuxieme chapitre, nous etudions l'action de l'acide selenique et de l'eau oxygenee sur la cholestanone-3, reaction qui nous a permis d'etudier la preparation et la stereochimie des derives du A-nor cholestane. Nous decrivons ensuite la preparation des A-nor cholestanols 2{alpha} et 2{beta} et des acetates correspondants. L'equilibration par des methodes chimiques de ces alcools montre que l'alcool 2 {alpha} est plus stable que l'alcool 2{beta}, ce qui est confirme par le calcul. Enfin, la reduction de la A-nor cholestanone-2 par les metaux en dissolution conduit toujours de facon preponderante a l'epimere 2 {beta} le moins stable avec en outre formation de pinacols. Nous consacrons enfin le troisieme chapitre a l'etude des reductions de l'androstanone-17 et des stabilites relatives des deux alcools 17{alpha} et 17{beta}. Quel que soit le mode operatoire utilise, nous obtenons toujours presque exclusivement l'acool 17{beta} le plus stable. D

  8. Reduction by metals dissolved in liquid ammonia of keto steroids. Equilibration of the alcohols; Reduction par les metaux dissous dans l'ammoniac liquide de cetones en serie steroide. Equilibration des alcools

    Energy Technology Data Exchange (ETDEWEB)

    Giroud, A.M. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    'une cetone par les metaux en dissolution fait intervenir deux electrons: on peut considerer comme intermediaire un radical-anion, puis un dianion ou un carbanion. Le radical-anion pouvant aussi se dimeriser pour donner des pinacols. Pour interpreter les resultats des reductions, il nous fallait connaitre les stabilites relatives des alcools ce qui nous a conduit a faire des equilibrations. Dans un premier chapitre, nous etudions les methodes de preparation de l'androstanone-ll et des androstanols-ll{alpha} et ll{beta}. Nous verifions ensuite qu'il n'est pas possible selon nos methodes de conclure sur la stabilite relative des deux alcools par equilibrations experimentales. Nous decrivons enfin les methodes de reduction de la cetone par les metaux alcalins et alcalino-terreux dissous dans l'ammoniac liquide, suivant deux procedes: soit en presence de donneur de protons, soit avec addition posterieure de donneur de protons. Ces reductions conduisent a un melange des deux alcools ou l'isomere {alpha} equatorial stable predomine. Dans un deuxieme chapitre, nous etudions l'action de l'acide selenique et de l'eau oxygenee sur la cholestanone-3, reaction qui nous a permis d'etudier la preparation et la stereochimie des derives du A-nor cholestane. Nous decrivons ensuite la preparation des A-nor cholestanols 2{alpha} et 2{beta} et des acetates correspondants. L'equilibration par des methodes chimiques de ces alcools montre que l'alcool 2 {alpha} est plus stable que l'alcool 2{beta}, ce qui est confirme par le calcul. Enfin, la reduction de la A-nor cholestanone-2 par les metaux en dissolution conduit toujours de facon preponderante a l'epimere 2 {beta} le moins stable avec en outre formation de pinacols. Nous consacrons enfin le troisieme chapitre a l'etude des reductions de l'androstanone-17 et des stabilites relatives des deux alcools 17{alpha} et 17{beta}. Quel que soit le mode operatoire utilise, nous

  9. Contraste de un modelo de envejecimiento exitoso derivado del modelo de Roy

    Directory of Open Access Journals (Sweden)

    María Amparo Kantún Marín

    2017-01-01

    Full Text Available Se formula y contrasta un modelo de envejecimiento exitoso derivado del modelo de adaptación de Roy. Se analizó una muestra no probabilística de 255 adultos mayores de seis centros sociales y un centro médico de consulta externa en Nuevo León, México. Se usó un modelamiento de ecuaciones estructurales. En el modelo final los estímulos focales de autopercepción del envejecimiento, entorno peatonal inmediato y el estímulo contextual de síntomas depresivos incidieron sobre el afrontamiento, que a su vez predijo el envejecimiento exitoso. El modelo tuvo buen ajuste al añadirse dos correlaciones entre residuos de medida de afrontamiento y envejecimiento exitoso. Los resultados obtenidos sugieren que el afrontamiento es un indicador directo del envejecimiento activo.

  10. Estrategia de cobertura con productos derivados para el mercado energético colombiano

    Directory of Open Access Journals (Sweden)

    Jhon Alexis Díaz Contreras

    2014-01-01

    Full Text Available El desarrollo que ha presentado el mercado mayorista de energía en Colombia ha permitido que hoy en día se estén negociando futuros de electricidad en el mercado de capitales local. Este trabajo tiene como objetivo diseñar un producto derivado en el que subyace el precio de la electricidad. Para esto, se analiza la serie de tiempo del precio de la electricidad para modelar su volatilidad; y a partir de esta, se diseña una opción exótica tipo barrera que muestra cómo se pueden usar este tipo de productos financieros en la cobertura de riesgos de los agentes del mercado.

  11. Estrategia de cobertura con productos derivados para el mercado energético colombiano

    Directory of Open Access Journals (Sweden)

    Jhon Alexis Díaz Contreras

    2014-01-01

    Full Text Available El desarrollo que ha presentado el mercado mayorista de energía en Colombia ha permitido que hoy en día se estén negociando futuros de electricidad en el mercado de capitales local. Este trabajo tiene como objetivo dise ̃ nar un producto derivado en el que subyace el precio de la electricidad. Para esto, se analiza la serie de tiempo del precio de la electricidad para modelar su volatilidad ; y a partir de esta, se dise ̃ na una opción exótica tipo barrera que muestra cómo se pueden usar este tipo de productos financieros en la cobertura de riesgos de los agentes del mercado.

  12. Microondas doméstico na síntese de derivados ftalimídicos

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    J. L. SANTOS

    2009-01-01

    Full Text Available

    Microondas são utilizadas na síntese orgânica desde 1986, e mostra-se vantajosa em diversos aspectos como possibilidade de maiores rendimentos, maior seletividade e menor decomposição térmica. A ftalimida e derivados, constituem-se em uma importante classe de compostos utilizados na química orgânica sintética, e do ponto de vista da Química Farmacêutica e Medicinal, é considerada um importante bióforo constituindo subunidade estrutural de caráter farmacofórico para uma série de compostos com diferentes atividades farmacológicas, entre elas, a anemia falciforme. O objetivo deste trabalho foi desenvolver metodologia alternativa na síntese de derivados ftalimídicos explorando a condensação de anidrido ftálico com aminas funcionalizadas sob radiação de microondas doméstico. Os resultados mostraram que os compostos ftalímidicos sintetizados podem ser obtidos em menores tempos reacionais (5-10 minutos e maiores rendimentos (60-89% quando comparados ao aquecimento convencional (refluxo, demonstrando o potencial da utilização do microondas na obtenção destas moléculas. Palavras-chave: microondas; ftalimidas; síntese.

  13. Prise en charge en soins primaires des troubles liés à l’usage d’alcool et de la consommation à risque

    Science.gov (United States)

    Spithoff, Sheryl; Kahan, Meldon

    2015-01-01

    Résumé Objectif Présenter aux médecins de soins primaires des renseignements et des conseils fondés sur des données probantes concernant la prise en charge de la consommation à risque et des troubles liés à l’usage d’alcool (TUA). Sources des données Nous avons entrepris une recherche documentaire non systématique à l’aide d’expressions de recherche en anglais, notamment primary care; screening, interventions, management et treatment; et at-risk drinking, alcohol use disorders, alcohol dependence et alcohol abuse; ainsi que des interventions spécifiques en médecine et en counseling pertinentes aux soins primaires. Principaux messages Dans le cas de patients ayant une consommation à risque ou un TUA, les médecins devraient offrir du counseling et, au besoin (p. ex. les patients dont le TUA est de modéré à grave), prescrire et connecter. Counseling : Offrir à tous les patients ayant une consommation à risque une brève séance de counseling et un suivi. Offrir à tous les patients ayant un TUA des séances de counseling et un suivi constant (fréquent et régulier). Prescrire : Offrir des médicaments (disulfiram, naltrexone, acamprosate) à tous les patients ayant un TUA de modéré à grave. Connecter : Encourager les patients souffrant d’un TUA à suivre des programmes de counseling de jour ou en résidence et d’adhérer à des groupes d’entraide. S’il est indiqué de le faire, demander une consultation pour le patient auprès d’un spécialiste en médecine des dépendances, de services concurrents en santé mentale et en toxicomanie ou une thérapie spécialisée pour traumatisme. Conclusion Les médecins de famille peuvent prendre en charge efficacement les patients qui ont une consommation à risque ou des TUA.

  14. L'auto adaptation à des mélanges essence/alcool utilisés comme carburant automobile: le moteur souple The Self-Adapting of Gasoline/Alcohol Mixtures Used As Automotive Fuel: the Flexible Engine

    Directory of Open Access Journals (Sweden)

    Dorbon M.

    2006-11-01

    Full Text Available Le moteur souple est un moteur susceptible d'être alimenté par des carburants constitués de mélanges d'une essence classique et d'un alcool léger (méthanol ou éthanol; si la concentration de chacun des composants de ces mélanges varie, les réglages nécessaires au bon fonctionnement du véhicule se font automatiquement. Dans cet article, sont tout d'abord exposées les propriétés caractéristiques en tant que carburant automobile de l'un de ces alcools légers, le méthanol. Puis viennent les descriptions des dispositifs qui font le moteur souple c'est-à-dire d'une part les systèmes de reconnaissance du carburant et d'autre part les appareillages susceptibles de modifier les réglages du moteur (alimentation et allumage en fonction de la qualité du mélange consommé. A flexible engine is one capable of running on fuels consisting of mixtures of conventional gasoline and a light alcohol (methanol or ethanol. If the concentration of each of these components of such mixtures varies, the tuning required for the proper running of the vehicle takes place automatically. This article begins by describing the characteristic properties of one of these light alcohols (methanol as an automotive fuel. Then the equipment is described that makes an engine flexible, i. e. both the fuel recognition systems and the equipment capable of changing engine tuning (feed and ignition as a function of the quality of the mixture burned.

  15. Étude de cas : la consommation d'alcool et sa représentation sociale dans les séries télévisées américaines et françaises ces 15 dernières années.

    OpenAIRE

    Mentior, Nathalie

    2017-01-01

    Ce mémoire a comme objectif principal de comprendre la représentation sociale de la consommation d'alcool dans les séries télévisées américaines et françaises durant ces 15 dernières années. Mais également quelle influence que celles-ci peuvent-elles avoir sur les téléspectateurs. À travers deux volets : une partie théorique et une analyse de contenu. Le volet théorique établit différentes notions telles que : la représentation sociale de l'alcool et de l'alcoolisme, les stéréotypes de la con...

  16. Riesgos y daños a la salud derivados del uso de videoterminal

    Directory of Open Access Journals (Sweden)

    Tamez González Silvia

    2003-01-01

    Full Text Available OBJETIVO: Evaluar la relación de daños a la salud con el uso de videoterminal, riesgos laborales y factores psicosociales en trabajadores de un diario informativo. MATERIAL Y MÉTODOS: En 1998 se estudió una muestra representativa (n=68 de una población de 218 trabajadores de un diario informativo de la Ciudad de México. Se presentan los resultados obtenidos a partir de una encuesta de autoaplicación, los cuales fueron comparados posteriormente con datos de exámenes clínicos. La hipótesis de esta investigación sustenta que, tanto el uso actual como la exposición acumulada de videoterminal, se asocian con mayor riesgo de presentar padecimientos visuales, músculo-esqueléticos y dermatológicos; trastornos mentales y psicosomáticos, y fatiga general. Los resultados fueron analizados en función de diferentes riesgos laborales: (riesgo visual, trabajo sedentario, uso de mouse, riesgo postural, calor excesivo y hacinamiento y factores psicosociales derivados de la organización del trabajo (demandas psicológicas, control sobre el trabajo y apoyo social. Para valorar su relación con los daños derivados del uso de videoterminal, se estimaron razones de prevalencias ajustadas por confusores potenciales (edad, sexo y escolaridad. RESULTADOS: Las mujeres presentaron prevalencias más elevadas de trastornos músculo-esqueléticos en la mayoría de los daños investigados, y las diferencias fueron significativas entre ambos sexos para dermatitis y eczema seborreico. El uso de videoterminal se asoció con mayor riesgo de fatiga neurovisual, trastornos músculo-esqueléticos en manos y extremidades superiores, dermatitis y eczema seborreico. De los riesgos laborales, los más asociados con trastornos fueron el uso de mouse y el riesgo postural. Los factores psicosociales se relacionaron principalmente con los padecimientos de naturaleza psicológica (trastornos mentales, psicosomáticos y fatiga general. CONCLUSIONES: Con el uso intensivo de

  17. Séparation des mélanges eau-alcool à l'aide du CO2 supercritique : application au mélange éthanol eau Separation of Water-Alcohol Mixtures by Supercritical CO2: Application of the Ethanol- Water Mixture

    Directory of Open Access Journals (Sweden)

    Fogel W.

    2006-11-01

    Full Text Available Les marchés accessibles à la technique d'extraction supercritique utilisant le CO2 seront plutôt orientés vers les alcools dérivés de la pétrochimie (isopropanol, butanol secondaire ou du gaz de synthèse (mélange d'alcools allant de l'éthanol à l'hexanol que vers les produits issus des fermentations pour lesquels la sélectivité de la séparation est théoriquement insuffisante et la concentration en alcool dans le moût fermenté trop faible. Markets for the supercritical extraction technique using CO2 will mainly be aimed for alcohols derived from petrochemicals (isopropanol, secondary butanol or from synthetic gas (mixture of alcohols ranging from ethanol to hexanol rather than for products from fermentations for which separation selectivity is theoretically insufficient and the alcohol concentration in the wort much too weak.

  18. Los instrumentos financieros derivados: concepto, operación y algunas estrategias de negociación

    Directory of Open Access Journals (Sweden)

    Vernor Mesén Figueroa

    2008-06-01

    Full Text Available Uno de los instrumentos financieros más sofisticados y que ha presentado mayor crecimiento en los volúmenes negociados durante los últimos años, son los derivados, por ello el interés en escribir acerca de este tema. Un derivado es un instrumento financiero el cual está vinculado al valor de un activo subyacente, que pueden ser commodities, acciones, bonos, tasas de interés, divisas, entre otros. Existen diferentes tipos de derivados, entre ellos: futuros, forwards, opciones y swaps. Estos instrumentos son negociados tanto en mercados organizados como no organizados, más comúnmente conocidos como OTC (Over The Counter y comúnmente son utilizados como instrumento de cobertura o especulación. El presente artículo pretende acercar al lector a este concepto: sus características, tipos, operación y algunas estrategias de negociación de estos productos.

  19. Virulencia de cepas de Listeria monocytogenes procedentes de cabras y sus derivados

    Directory of Open Access Journals (Sweden)

    Guicela Ramírez Bernal

    2014-01-01

    Full Text Available Se evaluó la virulencia de cepas de Listeria monocytogenes todas de serotipo 4b procedentes de cabras y sus derivados. Se observaron niveles de virulencia variables cuando se comparó la virulencia relativa (porcentaje de letalidad en ratones BALB/c inoculados vía intravenosa o intragástrica y su capacidad para infectar macrófagos J774A.1, y células epiteliales Caco-2. Dos cepas obtenidas de alimento de cabras produjeron 100 % de letalidad por ambas vías de inoculación y no mostraron diferencia significativa con la cepa testigo (P>0.05 respecto al porcentaje de invasión y a los parámetros de la cinética de crecimiento cuadrática observada en ambas líneas celulares. Si bien todas las cepas lograron invadir las células Caco-2, solamente algunas consiguieron invadir el bazo después de la inoculación por vía intragástrica. Las dos cepas provenientes de alimento de cabras fueron las más virulentas, representando un riesgo para la salud humana y animal, ya que pueden ser diseminadas en el hato y de este a otras explotaciones o a las instalaciones donde se elaboran alimentos.

  20. APOIO À DECISÃO DE COMPRA NA INDÚSTRIA DE CIMENTOS E DERIVADOS

    Directory of Open Access Journals (Sweden)

    Renan Felinto de Farias Aires

    2017-03-01

    Full Text Available O setor da construção civil é um dos mais dinâmicos setores da economia brasileira, impactando toda a complexa cadeia de atividades ligadas à construção, como, por exemplo, a produção de cimento. Assim, todas as indústrias ligadas à produção desse material necessitam tomar decisões da melhor maneira de forma a competirem no acirrado mercado brasileiro de cimento - quarto maior produtor do mundo. Por conta disso, o objetivo deste estudo é desenvolver um modelo multicritério para apoiar a compra de uma linha de ensacamento e paletização de pós para uma indústria de cimentos e derivados. Para isso, este estudo de caso exploratório empregou o método ELECTRE II ao problema a partir de quatro critérios. O resultado é apresentado por meio de um ranking das alternativas estudadas e as implicações deste. Concluiu-se que os resultados apresentados foram satisfatórios devido à robustez e a implicação prática dos mesmos.

  1. PROSPECÇÃO TECNOLÓGICA DE FOTOPROTETORES DERIVADOS DE PRODUTOS NATURAIS

    Directory of Open Access Journals (Sweden)

    Jackson Roberto Guedes da Silva Almeida

    2013-03-01

    Full Text Available A radiação ultravioleta é responsável por causar danos cumulativos à pele podendo evoluir para patologias mais severas como, por exemplo, o câncer de pele. A utilização de fotoprotetores é uma alternativa para prevenir essas doenças. Atualmente, os fotoprotetores vêm sendo desenvolvidos a partir de produtos de origem vegetal, com boa aceitação popular. O objetivo deste estudo foi realizar uma prospecção tecnológica de fotoprotetores derivados de produtos naturais, analisando a participação do país nos depósitos de pedido de patente em bases nacionais e internacionais até o momento. Para isso, a prospecção foi realizada no Banco Europeu de Patentes, no banco da Organização Mundial de Propriedade Intelectual, no Banco Americano de Marcas e Patentes e no banco de dados do Instituto Nacional de Propriedade Industrial do Brasil. A classificação internacional mais abundante nessa prospecção foi A61K. O maior número de patentes foi depositado nos últimos 10 anos. Dentre os maiores depositários, estão China, Estados Unidos, Japão e República da Coréia.

  2. Antagonismo Fosforo-Zing en un Suelo Derivado de Cenizas Volcánicas

    Directory of Open Access Journals (Sweden)

    Gaona J. Santiago

    1980-09-01

    Full Text Available Se sabe que existe una estrecha relación entre el P y el ln, llegándose a notar la influencia que tiene cada uno de ellos sobre la absorción y utilización por la planta en presencia de cantidades no deseables de uno u otro de los elementos en el suelo. Esta relación ha sido objeto de numerosas investigaciones, especialmente en los EE.UU. A pesar de los resultados obtenidos aún se requiere de más información, especialmente para los suelos colombianos, en donde los estudios que se tienen sobre este fenómeno son pocos y ya comienza a observarse los efectos de fertilizantes fosfóricos en la absorción y utilización del Zn por las plantas. Los suelos del Oriente Antioqueño, derivados de cenizas volcánicas, son extremadamente deficientes en P y este elemento es el más limitante. En la mayoría de los casos la producción de los cultivos es baja sin aplicaciones altas de P. Los agricultores de la región aplican altas dosis de P y no aplican ln. En esta región se han observado síntomas de deficiencia de ln como resultado de altas aplicaciones de P; cuando no se aplica P o se hace en cantidades bajas, los síntomas de deficiencia de ln se presentan en muy pocos casos.

  3. Queratinocitos derivados de piel humana modificados por el vector retroviral FOCH 29-NeoR

    Directory of Open Access Journals (Sweden)

    Luz Marina Restrepo

    2000-02-01

    Full Text Available

    En este protocolo se evaluará la eficiencia de la transducción mediada por el vector retroviral FOCH 29-NeoR derivado del virus de Friend; éste ha mostrado una alta eficiencia en la transducción, tanto de células madres hematopoyéticas como de otras líneas celulares. Se medirá su eficiencia de transducción en cultivos primarios de queratinocitos, derivados de biopsias de piel humana o de sobrantes de procedimientos quirúrgicos como circuncisiones, mastectomías y cirugía cosmética de pacientes que consultan el Hospital Universitario San Vicente de Paul, Hospital la María, la Clínica del Rosario y la Clínica León XIII.

    Las muestras de piel se procesarán en un lapso no superior a 12 horas, se eliminará el exceso de dermis y tejido conectivo por digestión con dispasa (0.6-2.4 U/ml a 37°C durante 1 hora. Las muestras serán lavadas con PBS, antibiótico (penicilina + estreptomicina y se cortarán en fragmentos de 1-2 mm; después de 2-3 horas de digestión con tripsina-EDTA (0.25% las células serán resuspendidas en KGM (Medio de crecimiento para queratinocitos y se sembrarán a una concentración de 105 - 3x105 células por plato de 100 mm; se incubarán a 37°C, 5% CO2 con cambios de medio 2-3 veces por semana. Se harán subcultivos con el fin de expandirlos y congelar una parte de las

  4. Análisis del impacto de los derivados de crédito en el sistema bancario

    OpenAIRE

    Rodríguez Gil, Luis Ignacio

    2012-01-01

    Los derivados de crédito constituyen una de las innovaciones financieras más recientes. A pesar de su “corta vida”, irrumpieron con fuerza en los mercados, produciéndose un aumento exponencial de estos instrumentos en la última década. Según Hirtle (2007), “El desarrollo de estos instrumentos es una innovación importante, la última de una serie de innovaciones, tales como la venta de préstamos de los años ochenta y la titulización de la década de los noventa, que han tenido un ...

  5. Bioacessibilidade in vitro das biotoxinas marinhas ácido ocadaico, dinofisistoxina-2 e seus derivados em bivalves crus e cozinhados

    OpenAIRE

    Manita, Diana Filipa Pereira

    2017-01-01

    Dissertação de Mestrado em Segurança Alimentar As biotoxinas marinhas mais frequentes e abundantes em Portugal são as toxinas lipofílicas, nomeadamente as toxinas do grupo do ácido ocadaico (AO), que inclui as dinofisistoxinas (DTX1 e DTX2) e os seus derivados (DTX3), responsáveis pela intoxicação diarreica (DSP diarrhetic shellfish poisoning). A investigação da presença, variabilidade e transformação de biotoxinas marinhas em moluscos bivalves é de elevada importância não só p...

  6. Nuevos derivados asimétricos de la carbohidracida y tiocarbohidracida como reactivos analíticos

    OpenAIRE

    Morales Millán, María Teresa Auxiliadora

    1987-01-01

    1.- En la presente Memoria, se han estudiado las caracte rísticas físico-químicas y de las posibilidades analíticas de dos derivados asimétricos de la carbohidracida y tiocarbohidracida: la 1-(di-(2-piridil)metiliden)-5-(salicilmetiliden)-carbohidrazona (DPSC), y la 1-(di-(2-piridil)metiliden)-5-(salicilmetiliden)-tiocarbohidrazona (DPST). 2.- La síntesis de los reactivos se ha efectuado en dos pasos. En primer lugar se obtuvieron los correspondientes monoderivados siguiendo la técnica de...

  7. Mecanismo de acción antiinflamatoria de 5-O-desmetilnobiletina y derivados del catalpol en hipersensibilidad retardada.

    OpenAIRE

    Bas Infante, Esperanza

    2007-01-01

    RESUMEN La presente Tesis Doctoral se ha centrado en el estudio de 5-O-desmetilnobiletina (DMN), aislado de Sideritis tragoricanum sp. mugronensis, y los iridoides derivados del catalpol denominados escrovalentinósido (SV) y escropoliósido A (SC), aislados de Scrophularia auriculata sp. valentina. La selección de estos tres principios se basó en los estudios previos realizados en los cuales se demostraron las propiedades en modelos experimentales de inflamación aguda. Como métodos exper...

  8. Vitamina c e seus derivados em produtos dermatológicos : aplicações e estabilidade

    OpenAIRE

    Dalcin, Karina Borges; Schaffazick, Scheila Rezende; Guterres, Silvia Stanisçuaski

    2003-01-01

    A vitamina C (ácido ascórbico) tem sido muito utilizada em produtos cosméticos e dermatológicos por apresentar importantes efeitos fisiológicos na pele. Um dos principais efeitos do ácido ascórbico é no combate à pele foto-envelhecida, em decorrência de sua característica antioxidante. Entretanto, a estabilidade da vitamina C é muito prejudicada devido a suas propriedades físico-químicas, degradando-se facilmente em solução aquosa. Em vista disso, derivados hidrofílicos e lipofílicos da vitam...

  9. Estudio sobre la síntesis y reactividad de heterociclos quirales derivados de aminoazúcares.

    OpenAIRE

    Vega Holm, Margarita

    2001-01-01

    Falta palabras clave Como objetivo general nos propusimos el estudio de la influencia del esqueleto de hidratos de carbono en el curso estereoquímico de reacciones modelo importantes en síntesis orgánica. Se escogieron derivados de aminoazúcares por la versátil reactividad que el grupo amino proporciona, así como diversos tipos de unión del sustrato a modificar con el azúcar que supongan reacciones conocidas en la Química de los Hidratos de Carbono, y sencillas (o fáciles) al introducirlos...

  10. Películas fluorescentes azules basadas en derivados de poli-2,7-fluorenofenilideno

    Directory of Open Access Journals (Sweden)

    Mallavia, R.

    2004-04-01

    Full Text Available Quaternization of poly-(9,9-bis(6’-bromohexylfluorenephenylene by treatment with trimethylamine gas was used to obtain a water soluble ammonium salt copolymer. The neutral copolymer containing fluorene/phenylene alternating repeating units was obtained by a palladiumcatalyzed Suzuki coupling reaction. This strategy could be applied to prepare water soluble conjugated polymers with the ability to change the charge functionality. The polymers were characterized by gel permeation chromatography (GPC, 1H and 13C NMR spectroscopy, FT-IR spectroscopy, and thermogravimetric analysis (TGA. The neutral polymer was stable to over 300ºC, while the cationic polymer begins to degrade at 120ºC with a progressive loss of mass at 290ºC. The optical properties of the polymers were investigated in solution and solid phases by UV/VIS and fluorescent spectroscopy. Mesoporous silica thin films were prepared as a host matrix for the fluorescent copolymers.

    La cuaternización del poli-(9,9-bis(6’-bromohexilofluorenofenileno por tratamiento de trimetilamina gaseosa se emplea para obtener una sal de amonio del copolímero precursor soluble en agua. El copolímero neutro contiene unidades alternantes repetitivas de fluoreno/ fenilideno obtenidas mediante una acoplamiento de Suzuki con Pd (II. Los polímeros se caracterizaron por cromatografía de permeación (GPC, espectroscopia RMN de 1H y 13C , espectroscopia IR transformada de Fourier y análisis termogravimétrico (ATG. El polímero neutro mantiene la estabilidad hasta los 300ºC, mientras el derivado catiónico comienza a descomponer a 120ºC, con una progresiva perdida de masa hasta los 290ºC. Las propiedades ópticas de los polímeros se estudiaron en disolución y en películas mediante espectroscopias UV/VIS y de fluorescencia. Las películas delgadas de sílice mesoporosa se prepararon como materiales receptores de los copolímeros fluorescentes.

  11. Efectos adversos derivados de la exposición ocupacional a ozono industrial

    Directory of Open Access Journals (Sweden)

    M.ª Alejandra Arias-Hualpa

    2015-03-01

    Full Text Available Introducción: Los trabajadores que realizan tareas de soldadura, depuración de aguas, conservación de alimentos o desempeñan actividades en contacto con fotocopiadoras, lámparas de vapor de mercurio, generadores de rayos x y otros equipos de alta tensión se pueden encontrar expuestos a ozono, que a dosis altas, puede desencadenar una liberación endógena de mediadores de la inflamación produciendo irritación ocular y daño de la vía respiratoria superior e inferior, pudiendo llegar a producir enfermedad pulmonar obstructiva crónica o edema de pulmón. Objetivo: Revisar la literatura científica sobre los efectos adversos derivados de la exposición ocupacional a ozono industrial. Metodología: Se realizó una búsqueda en las principales bases de datos bibliográficas biomédicas, con el fin de recopilar artículos publicados que cumplieran los requisitos del estudio, sin fecha límite inferior, hasta noviembre 2014. Resultados: Se incluyeron en el estudio un total de 9 artículos que cumplían los criterios de inclusión. Como hallazgos del estudio se encontró un descenso de la ceruloplasmina como biomarcador de daño oxidativo pulmonar asociado a concentraciones de ozono superiores a los valores límites aceptados, así como aumento del riesgo de rinitis no infecciosa, EPOC leve y síntomas de asma, especialmente las sibilancias. Conclusión: Los estudios revelan que las dosis altas de ozono industrial pueden representar un riesgo para la salud en determinados grupos de trabajadores como los soldadores y del blanqueado de papel, en los que la patología respiratoria ocupa un papel importante entre los efectos adversos encontrados.

  12. Caracterização físico-química e sensorial de kefir tradicional e derivados

    Directory of Open Access Journals (Sweden)

    S. Weschenfelder

    2011-04-01

    Full Text Available Avaliaram-se diferentes populações de grãos de kefir tradicional e de seus derivados, o kefir, o kefir leban e o soro de kefir, quanto às características físico-químicas e sensoriais, quando inoculados em diferentes concentrações de leite padronizado, levando-se em consideração as variáveis tempo/temperatura de incubação, maturação e filtração. A manipulação da população de grãos de kefir foi eficaz na obtenção de produtos com características físico-químicas semelhantes. O volume de leite utilizado na incubação influenciou significativamente as características dos derivados. A avaliação sensorial de antepastos elaborados a partir de kefir leban, condimentados, apresentou boa aceitabilidade.

  13. The dynamics of some oxidative stress markers in 3, 6 and 12-months alcohol abstinent patients: possible relevance for the usage of antioxidants in alcohol withdrawal / Dinamica unor markeri ai stresului oxidativ la 3, 6 şi 12 luni de abstinenţă de la alcool: posibila relevanţă a utilizării de antioxidanţi

    Directory of Open Access Journals (Sweden)

    Petrariu Florin

    2014-12-01

    Full Text Available În prezentul articol am fost interesaţi să studiem relevanţa stresului oxidativ în cadrul proceselor legate de abstinenţa de la alcool, având în vedere în special faptul că literatura de specialitate este extrem de controversată în acest domeniu de cercetare. Astfel, am determinat nivelul unor markeri specifici ai stresului oxidativ la pacienţii selectaţi după 3, 6 şi 12 luni de abstinenţă de la alcool. 62 de pacienţi de sex masculin au fost selectaţi pentru studiu. În cadrul studiului s-au prezentat 33 de pacienţi pentru determinările bazale, 14 pacienţi la 3 luni, 14 pacienţi la 6 luni şi 15 pacienţi la 12 luni de abstinenţa de la alcool, în timp ce lotul control a inclus 32 de persoane sănătoase, potrivite ca vârstă si sex-ratio cu celelalte grupuri de studiu. Astfel, în ceea ce priveşte rezultatele, în cazul superoxid dismutazei (SOD am observat o diferenţă semnificativă între cele trei loturi de studiu (p<0.0001, precum şi o creştere semnificativă din punct de vedere statistic a valorilor SOD la pacienţii aflaţi la 3 luni (p<0.0001, 6 luni (p<0.0001 şi respectiv 12 luni (p<0.0001 de abstinenţa de la alcool, faţă de determinările bazale. De asemenea, în cazul glutation peroxidazei, am observat o diferenţă semnificativă din punct de vedere statistic între grupuri (p=0.0003, plus creşteri importante la 6 luni (p=0.03 şi 12 luni (p=0.006, faţă de determinările bazale. În ceea ce priveşte malondialdehida (MDA, ca şi principal marker al proceselor de peroxidare lipidică, am putut observa de asemenea diferenţe semnificative între grupurile de studiu (p<0.0001. Mai mult, în cazul tuturor celor 3 grupe de pacienţi s-au putut observa scăderi semnificative ale concentraţiei de MDA, în comparaţie cu determinările bazale (p=0.003 pentru 3 luni, p=0.01 pentru 6 luni şi p=0.0002 pentru 12 luni. În concluzie, aceste date confirmă un stress oxidativ crescut la pacienţii consumatori

  14. Evaluación de Lesiones Periapicales en Pacientes Derivados a Cirugía Periapical Mediante Tomografía Computarizada de Haz Cónico

    OpenAIRE

    Hernández Vigueras, Scarlette; Donoso Zúñiga, Manuel; Sanhueza Tobar, Claudio; Linco Olave, Jared; Riquelme Carrasco, Sebastián

    2017-01-01

    El uso de la tomografía computarizada de haz cónico (CBCT) en endodoncia ha ido en aumento, justificando su uso en casos más complejos, como cirugías periapicales. El objetivo fue evaluar las características imagenológicas encontradas en un grupo de pacientes derivados a cirugía periapical, mediante el uso de CBCT. Se realizó un estudio observacional descriptivo, en un grupo de pacientes, derivados a cirugía periapical, a los cuales se realizó un examen de CBCT, evaluación clínica y radiograf...

  15. Mercado consumidor de carne suína e derivados em Belo Horizonte Pork consumer market in Belo Horizonte, Brazil

    Directory of Open Access Journals (Sweden)

    I.G. Faria

    2006-04-01

    Full Text Available Avaliou-se o comportamento do mercado consumidor de carne suína e seus derivados em Belo Horizonte. Foram entrevistados 401 consumidores, homens e mulheres, maiores de 19 anos de idade, mantendo-se a proporcionalidade observada no censo populacional. Além de sexo e faixa etária, escolaridade, ocupação e renda familiar foram levantadas para compor os fatores condicionantes da pesquisa. A carne suína in natura é consumida até três vezes por semana pela maioria da população (61,6%, em função de seu sabor e versatilidade. A compra costuma ser feita num mesmo estabelecimento comercial, sendo preferidos os cortes feitos na hora. O consumo de derivados da carne suína é maior que o da carne in natura em razão da grande variedade de produtos. Os consumidores acreditam que a carne suína in natura e derivados sejam perigosos à saúde pelo excesso de gordura ou de colesterol (38,4% e por transmitir doenças (27,8%. Sexo, idade e renda familiar têm influência no consumo, mas não escolaridade e ocupação. As marcas dos produtos derivados aumentam a confiabilidade e indicam a origem, para a maioria dos consumidores. A população, embora mais atenta aos conceitos de alimentação saudável e segura, não conhece o significado e a função da rastreabilidade e certificação de origem dos produtos. Para aumentar o consumo e justificar a criação de programa de certificação da carne suína e derivados em Minas Gerais, é necessário campanha dirigida de marketing para eliminar os preconceitos em relação a estes produtos.This study aimed to assess the behavior of the consumer in relation to pork and pork products. Four hundred and one consumers, men and women over 19 years old, were randomly sampled from the residents of Belo Horizonte, Minas Gerais, to supply information about pork and pork products consumption, besides school background, occupation and family income. Consumption of fresh pork was directly affected by concepts related

  16. La transmisión de los derechos de propiedad intelectual derivados de la actividad investigadora realizada en la Universidad pública española

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    Rosalía Estupiñán Cáceres

    2014-12-01

    Full Text Available Este artículo analiza las luces y sombras de los procedimientos que prevé el ordenamiento jurídico español para la transmisión a terceros de los derechos de propiedad intelectual derivados de la actividad investigadora generada en el seno de las universidades públicas españolas.

  17. Análisis de Casos Concretos de Cooperación Hispano-Marroquí Derivados del 11-M

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    Luisa Barrenechea

    2017-05-01

    Full Text Available El proceso judicial por el atentado del 11 de marzo de 2004 en Madrid conllevó una importante cooperación internacional, especialmente con Marruecos, país de origen de varios de los autores. En este artículo se analizan en detalle cuatro casos de cooperación hispano-marroquí derivados del sumario del 11-M así como del sumario para investigar a las personas relacionadas con la ayuda a huir a los autores directos de los atentados de los trenes de Madrid y de la explosión de las bombas de Leganés. Los casos de estudio corresponden a los primeros ciudadanos marroquíes juzgados y condenados en su país por un delito de terrorismo cometido en otro Estado en el que estaban las pruebas incriminatorias

  18. Preparation of PtSn/C, PtRu/C, PtRh/C, PtRuRh/C and PtSnRh/C electrocatalysts using an alcohol-reduction process for methanol and ethanol oxidation; Preparacao e caracterizacao de eletrocatalisadores PtRu, PtSn, PtRh, PtRuRh e PtSnRh para oxidacao direta de alcoois em celulas a combustivel tipo PEM utilizando a metodologia da reducao por alcool

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Ricardo Rodrigues

    2009-07-01

    In this work, Pt/C, PtRh (90:10), PtRh/C (50:50), PtSn/C (50:50), PtRu (50:50)/C, PtRuRh/C (50:40:10) and PtSnRh/C (50:40:10) were prepared by an alcohol-reduction process with metal loading of 20 wt.% using H{sub 2}PtCl{sub 6}.6H{sub 2}O (Aldrich), SnCl{sub 2}.2H{sub 2}O (Aldrich),and RhCl{sub 2}.XH{sub 2}O (Aldrich) as metals sources and Vulcan XC72 as support. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry (CV). The electro-oxidation of ethanol was studied by CV, chronoamperomety at room temperature in acid medium and tests at 100 deg C on a single cell of a direct methanol or ethanol fuel cell. The EDX analysis showed that the metal atomic ratios of the obtained electrocatalysts were similar to the nominal atomic ratios used in the preparation. The diffractograms of electrocatalysts prepared showed four peaks at approximately 2{theta} =40 deg, 47 deg, 67 deg and 82 deg, which are associated with the (111), (200), (220) and (311) planes, respectively, of a face cubic-centered (fcc) structure characteristic of platinum and platinum alloys. The average crystallite sizes using the Scherrer equation and the calculated values were in the range of 2-3 nm. For Pt Sn/C and PtSnRh/C two additional peaks were observed at 2 = 34 deg and 52 deg that were identified as a SnO{sub 2} phase. Pt Sn/C (50:50) and PtSnRh/C (50:40:10) electro catalyst showed the best performance for ethanol oxidation at room temperature. For methanol oxidation at room temperature Pt Ru/C, Pt Sn/C and PtRuRh/C electrocatalysts showed the best performance. Tests at 100 deg C on a single cell of a direct ethanol fuel cell PtSnRh/C showed the best performance, for methanol oxidation PtRuRh/C showed the best performance. (author)

  19. Preparation of PtSn/C, PtRu/C, PtRh/C, PtRuRh/C and PtSnRh/C electrocatalysts using an alcohol-reduction process for methanol and ethanol oxidation; Preparacao e caracterizacao de eletrocatalisadores PtRu, PtSn, PtRh, PtRuRh e PtSnRh para oxidacao direta de alcoois em celulas a combustivel tipo PEM utilizando a metodologia da reducao por alcool

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Ricardo Rodrigues

    2009-07-01

    In this work, Pt/C, PtRh (90:10), PtRh/C (50:50), PtSn/C (50:50), PtRu (50:50)/C, PtRuRh/C (50:40:10) and PtSnRh/C (50:40:10) were prepared by an alcohol-reduction process with metal loading of 20 wt.% using H{sub 2}PtCl{sub 6}.6H{sub 2}O (Aldrich), SnCl{sub 2}.2H{sub 2}O (Aldrich),and RhCl{sub 2}.XH{sub 2}O (Aldrich) as metals sources and Vulcan XC72 as support. The electrocatalysts were characterized by EDX, XRD and cyclic voltammetry (CV). The electro-oxidation of ethanol was studied by CV, chronoamperomety at room temperature in acid medium and tests at 100 deg C on a single cell of a direct methanol or ethanol fuel cell. The EDX analysis showed that the metal atomic ratios of the obtained electrocatalysts were similar to the nominal atomic ratios used in the preparation. The diffractograms of electrocatalysts prepared showed four peaks at approximately 2θ = 40{sup 0}, 47{sup 0}, 67{sup 0} and 82{sup 0}, which are associated with the (111), (200), (220) and (311) planes, respectively, of a face cubic-centered (fcc) structure characteristic of platinum and platinum alloys. The average crystallite sizes using the Scherrer equation and the calculated values were in the range of 2–3 nm. For PtSn/C and PtSnRh/C two additional peaks were observed at 2θ = 34{sup 0} and 52{sup 0} that were identified as a SnO{sub 2} phase. PtSn/C (50:50) and PtSnRh/C (50:40:10) electrocatalyst showed the best performance for ethanol oxidation at room temperature. For methanol oxidation at room temperature PtRu/C, PtSn/C and PtRuRh/C electrocatalysts showed the best performance. Tests at 100 deg C on a single cell of a direct ethanol fuel cell PtSnRh/C showed the best performance, for methanol oxidation PtRuRh/C showed the best performance. (author)

  20. Effect of alcohol and formaldehyde on the ä13C and ä15N isotopic composition of Plagioscion squamosissimus and Hypophthalmus edentatus (Pisces, Osteichthyes = Efeito do alcool e formol sobre a composicao isotopica de ƒÂ13C e de ƒÂ15N em Plagioscion squamosissimus e Hypophthalmus edentatus (Pisces, Osteichthyes

    Directory of Open Access Journals (Sweden)

    Gislaine Iachstel Manetta

    2011-09-01

    Full Text Available The present study investigates the ƒÂ13C and ƒÂ15N isotopic composition in frozen samples (control, samples in alcohol and in formaldehyde of Plagioscion squamosissimus and Hypophthalmus edentatus. From each individual we extracted a strip of muscle from the region above the lateral line, in the dorsal fin base, that was divided into three equal parts, each one was submitted to one type of treatment: freeze . control group (-15oC, conservation in alcohol 70%and fixation in formaldehyde 4%. Samples were kept under those treatments for 30 days, washed and submerged in distilled water for 4 hours. Afterwards, they were dried up in air oven at 60oC for 48 hours and macerated until the obtaining of a fine powder. A significant difference was found in isotopic values of carbon and nitrogen, between the control and the samples in alcohol and formaldehyde, except for ƒÂ13C from the H. edentatus samples in formaldehyde. The carbon isotopic values of samples in alcohol were mostly enriched compared to control, whereas the samples in formaldehyde presented depleted values in relation to the control. The nitrogen isotopic values for both samples preserved in alcohol and formaldehyde were enriched when compared to the values of frozen samples, independently of used preservatives. Therefore, the isotopic correction should be accomplished according to the isotope and preservative employed for species of freshwater fish.O presente estudo investiga a composicao isotopica de ƒÂ13C e ƒÂ15N entre as amostras congeladas (controle, em alcool e em formol de Plagioscion squamosissimus e Hypophthalmus edentatus. De cada individuo foi extraida uma faixa de musculo localizada na regiao acima da linha lateral, na base da nadadeira dorsal, a qual foi subdividida em tres partes iguais, sendo cada uma delas submetida a um tipo de tratamento: congelamento - grupo control (-15oC, conservacao em alcool 70% e fixacao em formol 4%. As amostras foram mantidas nos

  1. Las competencias de los Länder y el derecho comunitario derivado ante el Tribunal Constitucional Alemán: Comentario a la sentencia del Bundesverfassungsgericht de 22 de marzo de 1995

    OpenAIRE

    Martín y Pérez de Nanclares, José

    1995-01-01

    Comentarios a la sentencia referida sobre el Derecho Comunitario Derivado según se apunta su desarrollo en el Tratado de Maastricht Comments that judgment on EU secondary law by development outlined in the Maastricht Treaty

  2. Posicionamento do consumidor frente ao consumo de leite de cabra e seus derivados na cidade de Natal-RN

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    Roberta Targino Pinto Correia

    2009-04-01

    Full Text Available A Região Nordeste têm concentrado ao longo da história grande parte do rebanho caprino brasileiro. É uma atividade econômica de grande importância para o sertanejo, já que serve como fonte de renda, subsistência e fator de fixação do homem no interior. Apesar de todo o potencial funcional e nutritivo já reconhecido desse tipo de leite, a caprinocultura leiteira ainda se caracteriza por ser uma atividade desenvolvida de forma empírica e extensiva e com baixos níveis de tecnologia, além de dificuldades no setor produtivo que incluem entraves na comercialização e pequeno número de produtos derivados disponíveis no mercado. A presente pesquisa tem o objetivo de avaliar o posicionamento do consumidor em Natal-RN quanto ao possível consumo do leite de cabra e derivados, tendo em vista a quase inexistência de trabalhos abordando esse aspecto. O trabalho tem caráter exploratório e descritivo, tomando como base as respostas obtidas de 400 indivíduos abordados na capital potiguar através de questionário estruturado composto por 15 questões sobre conhecimento do mercado, conhecimento nutricional, atitude e comportamento. Os resultados apontam para o desconhecimento sobre a qualidade nutricional do leite de cabra por parte dos entrevistados incluídos na pesquisa. Indicam também que os aspectos sensoriais odor e sabor, além da confiabilidade no produto, estão entre os elementos considerados na decisão de não comprar o leite caprino, ao passo que o potencial benefício á saúde é apontado como um dos parâmetros importantes para a aquisição do leite caprino.

  3. ESTUDIO SINTÉTICO Y CARACTERIZACIÓN POR INFRARROJO DE DERIVADOS 2-(AMINO-1,4-NAFTOQUINONA Y SU EVALUACIÓN ANTIBACTERIANA PRELIMINAR

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    Marlene Lariza Andrade-Guel

    2011-01-01

    Full Text Available Las naftoquinonas son compuestos de origen natural o sintético que han mostrado importantes actividades biológicas, resaltando como agentes antibacterianos, antifúngicos, antimaláricos y anticancerígenos. En el presente trabajo se reportan los resultados de la síntesis utilizando diferentes métodos como la síntesis a temperatura ambiente (STA, síntesis por calentamiento convencional (SCC y síntesis asistida por ultrasonido (SAU de los derivados 2-(amino-1,4-naftoquinona. Se realizó su caracterización por espectroscopía de infrarrojo. Además se determinó su capacidad como agentes antibacterianos frente a las cepas Proteus sp. y Enterococcus faecalis. La mayor actividad lo mostró el derivado 2-bencilamino 1,4-naftoquinona.

  4. Los derivados financieros, su impacto en la seguridad alimentaria y los intentos de regulación

    Directory of Open Access Journals (Sweden)

    Antonio Marquina

    2013-01-01

    Full Text Available Las consecuencias de la especulación con derivados financieros en la seguridad alimentaria se han ido progresivamente clarificando. El artículo enfatiza la excesiva especulación y la desregulación que se produjo a partir del año 2000, señalando que los factores que afectan a la oferta y la demanda no pueden explicar por sí solos la extremada volatilidad y la subida de los precios producida desde 2007. La financiarización de los mercados agrícolas impide que agricultores y comerciantes utilicen el mercado de futuros como una forma de seguro tal como habían venido haciendo y perjudica muy seriamente a los consumidores, especialmente en los Estados más pobres. En otro orden, una alta volatilidad de precios agrícolas conduce a menores beneficios de la producción agrícola, desalienta la inversión, la innovación y la búsqueda de una mayor productividad en la agricultura. El artículo explica los procesos de regulación realizados en Estados Unidos y la Unión Europea, así como el papel del G-20.

  5. Historia y actualidad de productos para la piel, cosméticos y fragancias. Especialmente los derivados de las plantas

    Directory of Open Access Journals (Sweden)

    Francisco José González Minero

    Full Text Available Resumen Objetivo: aportar notas históricas sobre el empieo de los recursos vegetales en la elaboración de productos para el cuidado de la piel y recoger hechos científicos que nos definen la actualidad del tema. Método: búsqueda bibliográfica a través de las bases de datos: Scopus, WOS, Google Scholar y The Plant List y otras web botánicas. Resultados y discusión: el cuidado de la piel y la cosmética forman parte de nuestra vida diaria, de ahí que el uso de preparados para este fin haya aumentado significativamente en los últimos aňos. A partir de una bibliografia reciente, citamos 78 taxa botânicos (algas, helechos y plantas con semilla, hongos incluídos relacionados con hechos históricos y conocimientos científicos actuales. Conclusión: Los derivados de los vegetales se consideran seguros para la salud, suponen una gran fuente de metabolitos secundarios y han sido y son materia prima para la elaboración de productos que cuidan la piel.

  6. ESTUDO DAS VARIÁVEIS OPERACIONAIS E CONJUNTURAIS SOBRE O MARKET VALUE DAS EMPRESAS DE CARNES E DERIVADOS NO BRASIL

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    Eduardo Pozzi Lucchesi

    2015-06-01

    Full Text Available O objetivo deste trabalho é identificar as variáveis relacionadas aos aspectos operacionais e conjunturais que influenciam o Market Value das empresas do segmento de carnes e derivados listadas na BM&FBovespa, no período de 2007 a 2013. O estudo foi elaborado sob a perspectiva de dois eixos teóricos. O primeiro foi uma análise das contribuições do Market Value como um indicador útil para determinação do valor justo de mercado criado aos acionistas e, portanto, constituindo uma base sólida para mensuração do desempenho das empresas. O segundo foi a Hipótese de Mercado Eficiente que considera a eficiência da informação ou o impacto de determinadas informações na precificação dos ativos. O modelo especificado produziu resultados que ratificaram algumas hipóteses da pesquisa, tanto na significância individual, quanto no sinal de algumas variáveis independentes. Além disso, o modelo apresentou significância global, dada pelo teste F, a 5%, com um coeficiente de determinação múltiplo ajustado de 9,22%.

  7. Visión Comunitaria de los Beneficios Derivados del Ecoturismo en el Parque Nacional Natural Amacayacu (Amazonas, Colombia

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    Fredy A Ochoa Fonseca

    2013-06-01

    Full Text Available El ecoturismo es visto como oportunidad para el desarrollo, la conservación y la generación de beneficios para las comunidades; bajo esta perspectiva, Parques Nacionales en el año 2004 entrega en concesión los servicios ecoturísticos del PNN Amacayacu, proceso que ha traído interrogantes e inconformidades. Esta investigación busca analizar la visión que tienen las comunidades del PNN Amacayacu sobre los beneficios derivados del ecoturismo, mediante una metodología cualitativa que establece la percepción de la comunidad frente al problema. Los resultados muestran al ecoturismo como un modelo exógeno de desarrollo que genera beneficios, pero también impactos en los modos de vida y la cultura local; muestran también que, más allá de los beneficios monetarios, existen otros como la participación en la toma de decisiones que son más valiosos para las comunidades. Finalmente, muestra la relevancia de cuestionarse sobre cuál es el tipo de desarrollo al que se le apunta desde el ecoturismo y la importancia de que sean las mismas comunidades quienes lo definan.

  8. Cross-Linking of P.V.A. by Gamma Radiation; Reticulation de l'alcool polyvinylique par les rayons gamma; Dejstvie gamma-luchej na poperechnuyu svyaz' polivinologo spirta; Reticulacion del alcohol polivinilico por irradiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Dieu, H; Desreux, V

    1960-07-15

    The action of gamma rays on aqueous solutions of polyvinyl alcohol was observed by determination of the viscosity, sedimentation constant and acetylation rate. There was a very definite critical concentration, 0.28%, below which a B gel could not be formed by any dose. Above the critical concentration, the chief reaction was apparently intermolecular cross-linking which increased with dosage. Below the critical concentration the reactions were much more complex. At small doses there was probably some competition between inter- and intra- molecular cross-linking and the formation of more symmetrical molecular clusters. At higher doses the aggregates and the molecular clusters were subject to more and more internal and external cross-linking, leading finally to the formation of micro-gel particles. At decreasing concentrations (0.2 - 0.6%) intra-molecular cross-linking apparently became increasingly important. The effects of radiation were thought to depend upon the initial concentration of the polyvinyl alcohol solutions. (author) [French] L'action des rayons gamma sur des solutions aqueuses d'alcool polyvinylique a ete suivie par determination de la viscosite, de la constante de sedimentation et du taux d'acetylation. Il existe une concentration critique bien definie 0,28%, au-dessous de laquelle il est impossible d'obtenir la formation d'un gel B quelque soit la dose. Au-dessus, le phenomene important semble etre une reticulation intermoleculair e qui augmente avec la dose. Au-dessous de la concentration critique, les phenomenes sont beaucoup plus complexes. Aux faibles doses il y a probablement competition entre les phenomenes de pontage inter- et intramoleculaires et formation d'amas moleculaires de configuration plus symetrique. A doses plus fortes, les aggregats et les amas moleculaires subissent un pontage interne et externe de plus en plus prononce avec finalement formation de particules de micro-gel. A des concentrations de plus en plus faibles (0

  9. 3-O-α-L-RAMNOPIRANOSILFLAVONOIDES Y OTROS DERIVADOS FENÓLICOS DE HOJAS DE Calliandra calothyrsus. MEISSNER (MIMOSACEAE.

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    Bárbara Moreno Murillo

    2009-04-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} El estudio químico del extracto polar de hojas de Calliandra calothyrsus. Meissner (Mimosaceae (accesión CIAT 22316 condujo a la identificación de dos flavonoides glicosilados: 3-O-α-L-ramnopiranosil-7-metoxi-5,3',4'-trihidroxiflavona y 3-O-α-L-ramnopiranosil-5,7,3',4'-tetrahidroxiflavona; sus estructuras fueron elucidadas por métodos espectroscópicos IR y RMN (1D y 2D. Adicionalmente, por espectrometría de masas por las técnicas DART y ESI  de alta resolución, se identificaron derivados fenólicos mayoritarios tales como ácido gálico y su dímero (PM 339,032, dihidroxicumarina, trihidroxicumarina, quercetina, dihidroquercetina, 3-O-α-L-ramnopiranosil-7-metoxi-5,3',4'-trihidroxiflavona,3-O-α-L-ramnopiranosil-5,7,3',4'-tetrahidroxiflavona y un dímero de flavonoide como principales constituyentes químicos.

  10. Fuentes de financiamiento utilizadas por las empresas productoras de derivados lácteos del estado Zulia

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    Mariby Boscán

    2007-01-01

    Full Text Available Actualmente, las empresas están viviendo transformaciones en muchos aspectos, para lo cual requieren la obtención de recursos financieros. El presente artículo tiene como objetivo determinar las fuentes de financiamiento públicas y privadas utilizadas por las empresas productoras de derivados lácteos del estado Zulia. Con esta finalidad, se realizó una investigación descriptiva y de campo, para lo cual se diseñó una entrevista aplicada a ocho gerentes. Entre los resultados destacan: Un 75% de los entrevistados, utilizan principalmente el crédito otorgado por FONCREI, como fuente pública, debido a que valoran fundamentalmente la tasa de interés; considerando además, que el acceso a este tipo de fuente es complicado (62,5%, y el tiempo de respuesta lento (87,5%. Como fuente de origen privado, figura el crédito con proveedores (62,5% siendo en este caso, el plazo otorgado por éstos el factor determinante; la mayoría de los empresarios estiman que el acceso a esta fuente es adecuado, los requisitos exagerados y el tiempo de respuesta adecuado. Se concluyó que el factor más importante en la decisión de solicitar el crédito público es la tasa de interés mientras que en las fuentes privadas, el plazo y monto del crédito son los factores más relevantes.

  11. Características de nuevos cultivos celulares derivados de tejidos embrionarios de Aedes aegypti (Diptera: Culicidae.

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    Ariosto Ardila

    2005-03-01

    Full Text Available Introducción. Los cultivos celulares de insectos son una metodología útil en estudios biomédicos y tecnológicos. Objetivo. El propósito principal del presente trabajo fue obtener y caracterizar cultivos celulares derivados de tejidos embrionarios de Aedes aegypti. Materiales y métodos. Se emplearon huevos embrionados para los explantes de tejidos en los medios de cultivos MM/VP12 y L-15/Grace, con suplemento de 20% de suero fetal bovino y una mezcla al 1% de antibiótico y antimicótico, con un rango de pH entre 6,8 y 7,0. Los cultivos se incubaron a una temperatura de 28oC sin atmósfera de CO . Resultados. El crecimiento celular se obtuvo en el medio L-15/Grace, 3 semanas después de haber sido sembrados los tejidos embrionarios; sin embargo, se necesitaron 6 meses para la formación de la monocapa confluente. Desde agosto de 2003 hasta junio de 2004, se habían realizado 28 subcultivos. Las células se caracterizaron morfológicamente; predominaron las formas epitelioides en subcultivos de pases altos. También se reconocieron las particularidades morfométricas del cariotipo y, además, se determinaron los perfiles isoenzimáticos y moleculares de los cultivos celulares, los cuales se compararon con muestras de adultos de la especie tomadas de la misma colonia y con líneas celulares derivadas de otros insectos. Discusión. Estas células representan, potencialmente, un importante sistema in vitro en investigaciones básicas y aplicadas.

  12. Eventos adversos derivados del cuidado brindado en la Unidad de Cuidados Intensivos Adultos del Hospital Universidad del Norte. Barranquilla (Colombia

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    Elizabeth Villarreal Cantillo

    2014-01-01

    Full Text Available Objetivo: Determinar los eventos adversos derivados del cuidado brindado en la Unidad de Cuidados Intensivos del Hospital Universidad del Norte (en Barranquilla en el periodo enero-diciembre de 2012. Materiales y métodos: Estudio descriptivo transversal retrospectivo. La muestra se obtuvo mediante un muestreo sistemático, a partir de un listado ordenado de todas las personas ingresadas al Hospital Universidad del Norte (HUN en los servicios de Urgencias, Hospitalización, Cirugía, UCI Adultos, UCI Neonatal, Gineco-Obstetricia, Consulta Externa, Radiología y Laboratorio que hubieran sufrido algún evento adverso ocurrido entre enero a diciembre de 2012. La información se obtuvo mediante la base de datos del Hospital Universidad del Norte. Para el análisis se utilizó Microsoft Excel 2010. Resultados: Durante 2012 se presentaron 130 (25 % casos de eventos adversos; siendo el segundo servicio con mayor número de eventos, después de Hospitalización. Las tres primeras causas de eventos adversos fueron: la infección nosocomial, con un 25 %; las úlceras por presión, con en un 18 %, y la neumonía asociada a ventilación mecánica, con un 16 %. Conclusiones: Los eventos adversos que más son reportados en las unidades de cuidados intensivos adultos son aquellos que ocurren cuando hay una mayor intervención en el paciente. Condiciona la aparición de eventos adversos un personal sanitario con déficit de conocimientos y falta de preparación. La ocurrencia de estos eventos adversos pone en peligro la vida de los seres humanos, debido a que empeoran su condición, produce sobrecosto y al profesional le genera sobrecarga laboral y afectiva.

  13. Aplicación de productos derivados del insecto Dactylopius coccus Costa (Homóptera, Dactylopiidae Aplicación de productos derivados del insecto Dactylopius coccus Costa (Homóptera, Dactylopiidae

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    Lorena Vargas Rodríguez

    2012-02-01

    Full Text Available   Nowadays many industries want to replace synthetic dyes by natural, due to its harmful effects and the high contamination of the environment. Dactylopius coccus Costa (cochi­neal is an insect to obtain natural products that are used as dyes. The aim of this study was to promote the application of cochineal and the products derivates of these insect, in the dyeing of cotton fabric and in the coloration of a lipstick bullet at the laboratory. Was applied to the aqueous extract of cochineal on cotton fabric, obtaining homogeneous colors, with average values in the CIELab scale of: 43.81±0.33 L*, 44.64±0.15 a* y -4.03±0.55 b*. It also was applied the carmine pigment in the elaboration of a lipstick bullet, was obtai­ned consistent color with the following average values on the CIELab scale: 13.25±3.62 L*, 4.80±1.41 a* y -0.23±0.84 b*. Actualmente muchas industrias buscan sustituir los colorantes sintéticos por naturales, debido a su efecto nocivo y a la alta contaminación del medio ambiente. Del insecto Dactylopius coccus Costa (grana carmín se obtienen productos naturales que se pueden usar como colorantes, por lo que el objetivo de este trabajo fue difundir la aplicación del insecto grana carmín y los productos derivados del mismo en el teñido de una tela de algodón y en la coloración de una bala labial a nivel laboratorio. Al aplicar el extracto acuoso de la grana carmín sobre la tela de algodón, se consiguieron colores homogéneos, con valores promedio en la escala CIELab de: 43.81±0.33 L*, 44.64±0.15 a* y -4.03±0.55 b*. Asimismo al aplicar el pigmento laca carmín en la elaboración de una bala labial se lograron colores uniformes con los siguientes valores promedio en la escala CIELab: 13.25±3.62 L*, 4.80±1.41 a* y -0.23±0.84 b*.

  14. Utilização de consorcio microbiano para biorremediação do meio ambiente contaminado com derivados de petroleo.

    OpenAIRE

    Fabio Guimaro Dias

    2007-01-01

    Resumo: Neste trabalho foi formulado um consórcio microbiano para avaliação de seu potencial em degradar petróleo e seus derivados, em microcosmos e meio mínimo de sais. As 43 bactérias testadas na primeira fase do projeto demonstraram alguma propriedade que as classificam como potencialmente degradadoras de hidrocarbonetos. Todavia, as cepas 1, 9, 22, 23 e 36 demonstraram os melhores e mais homogêneos resultados em praticamente todos os parâmetros analisados, sendo estas, portanto, as cinco ...

  15. Productos del sector agrícola colombiano y derivados que tienen oportunidad de ser vendidos en el mercado de la Federación Rusa

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    Camacho Ferro, Juan Diego

    2016-01-01

    Este trabajo tuvo como fin identificar los productos del sector agrícola colombiano y derivados que tienen oportunidad de ser vendidos en el mercado de la Federación Rusa. Esto con el objetivo de tener un documento para los exportadores colombianos donde puedan consultar las oportunidades de negocio que tiene el sector y que pueden ser explotadas. El trabajo se adelantó mediante la consulta de fuentes de información terciaria, como los sitios web de distintas asociaciones, información de los...

  16. Aportes teóricos derivados de las investigaciones sobre el lenguaje entre el 2000 y el 2010: una revisión

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    Johny Villada Zapata; Liliana Chaves Castaño

    2012-01-01

    El artículo presenta el análisis de contenido derivado de una revisión sistemática en la que se retomaron 57 estudios que tenían el lenguaje como tema central. Las investigaciones consultadas arrojan diversos aportes teóricos de los cuales sobresale, en primer lugar, el origen social de este proceso, tanto en la filogénesis como en la ontogénesis. En segundo lugar puede afirmarse que su desarrollo se ve afectado negativa o positivamente por variables como la nutrición, la relación con los pad...

  17. Influencia de la concentración del precursor, catalizador y agente reductor en la síntesis de derivados del 2H-INDAZOL.

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    Ovalle Pérez, S.; Pérez Rodriguez, N.A.; Elizondo Martínez, P.; Velazoo Soto, M.A.

    2011-01-01

    La importancia de los derivados del2H-indazol es debida a la actividad biológica que han presentado, 10 que ha permitido aplicarlos en la industria farmacéutica, en el sector agrícola entre otros. En este trabajo, primeramente se estudió la influencia de la concentración del N,N'-bis(2-nitrobencil}-1,2-etanodiamina [PJ y diferentes cantidades tanto de agente reductor como de catalizador para favorecer la formación del 2,2' -(etano-I,2-

  18. EVALUACIÓN DE LAS PROPIEDADES DEL CAJARO (Phractocephalus hemiliopterus COMO POTENCIAL PARA LA OBTENCIÓN DE SURIMI Y PRODUCTOS DERIVADOS

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    Indira Sotelo D

    2008-12-01

    Full Text Available Objetivo. Determinar el uso potencial de carne de Cajaro (Phractocephalus hemiliopterus, para la obtención de surimi y productos derivados. Materiales y métodos. Filetes de Cajaro fueron troceados y lixiviados con agua en relación 1:3, formando pasta base surimi con la cual se preparó kamaboko, sometiendo la pasta moldeada a vapor (60oC durante 15 min; y chikuwa donde la pasta en forma de rollo fue cocida a 80oC por 10 min. Se determinó la proteína total por método Kjeldahl, la capacidad de retención de agua (CRA y el análisis de perfil de textura (TPA. El contenido de humedad se determinó por método AOAC (985.14 y se evaluó la calidad de la proteína miofibrilar por electroforesis SDS-page. Resultados. El Cajaro presentó un contenido proteico de 17.90±0.79% b.h.; porcentaje de humedad de 81.65±2.2% b.h. y CRA de 66.25±3.53% b.h. Los productos derivados presentaron 18.66±1.35% b.h., de proteína total equivalente a la proteína miofibrilar, influyendo en la gelificación por aumento de la CRA con respecto al surimi. El TPA incrementó (á=0.05 en la masticabilidad de la pasta base (51.04 N.s con respecto al kamaboko (480.80 N.s, generando características cohesivas a los productos derivados, frente a características adhesivas de la pasta base. En la electroforesis se evidenció que la calidad de la miosina en productos derivados se conservó después de congelados, mientras que en filete y pasta base se deterioró. Conclusiones. La calidad de la proteína miofibrilar de Cajaro evidencia el potencial tecnológico que tiene esta especie del Amazonas, convirtiéndose en una oportunidad de negocio para obtención de productos tipo surimi de alto valor nutricional con calidad exportable.

  19. Ingesta de leche y derivados lácteos en la población universitaria Intake of milk and dairy products in a college population

    OpenAIRE

    T. Durá Travé

    2008-01-01

    Objetivo: Realizar un estudio descriptivo del consumo de leche y derivados en una población universitaria y analizar su contribución nutricional en la dieta de estos universitarios. Material y métodos: Registro de consumo de alimentos de un día lectivo (recuerdo de 24 horas) a una muestra aleatoria de 500 universitarios con edades comprendidas entre 19 y 24 años. De cada encuestado se registraba sexo, edad, estudios universitarios, horario de clases y tipo de residencia. Resultados: El 98,6% ...

  20. Derivados azufrados de N-acetilhexosaminas y su uso como inhibidores de la división de células tumorales

    OpenAIRE

    Fernández-Mayoralas, Alfonso; Nieto-Sampedro, Manuel; Casas Brugulat, Josefina; García-Álvarez, Isabel; Romero-Ramírez, Lorenzo

    2010-01-01

    como inhibidores de la división de células tumorales. La presente invención describe una serie de tioglicósidos y sus derivados oxidados sulfóxido y sulfona, que confieren mayor solubilidad en medios acuosos, y su uso como antitumorales, principalmente frente a líneas celulares de glioma y adenocarcinoma de pulmón. Los nuevos tioderivados son resistentes a la hidrólisis catalizada por enzimas N-acetilhexosaminidasas y reducen el contenido de gangliósidos en células ...

  1. Síntesis y caracterización de surfactantes derivados de sales biliares, éteres corona, adamantanos y cadenas hidrocarbonadas

    OpenAIRE

    Trillo Novo, Juan Ventura

    2015-01-01

    La presente Tesis doctoral abarca aspectos relacionados con la Química supramolecular, el Biomimetismo molecular y la Fisicoquímica de coloides. El estudio ha implicado el diseño, la síntesis y la caracterización en disolución acuosa de numerosos compuestos entre los que sobresalen los derivados de las sales biliares, los éteres corona y grupos hidrófobos como los adamantanos y las cadenas hidrocarbonadas. Comparados con los surfactantes clásicos, los nuevos compuestos ev...

  2. Qualidade físico-química, microbiológica e ocorrência de micotoxinas de Alternaria alternata em derivados de tomate

    OpenAIRE

    Santos, Grazielle Gebrim

    2014-01-01

    O tomate industrial destina-se à produção de derivados, como extratos, polpas, molhos e conservas de tomate sem pele. A indústria de processamento de tomates no Brasil apresentou um grande crescimento a partir da década de 1970. O Brasil figura entre os dez maiores produtores de tomate industrial do mundo. A cultura do tomate é afetada por um grande número de doenças causadas por fungos e bactérias. Entre os fungos produtores de toxinas que acometem os tomates industriais destacam-se os do gê...

  3. Absorción de la Bencidrilamina y derivados : I. Selección de la metodología analítica

    OpenAIRE

    Volonté, María Guillermina; Taylor, Susana A.; Lufrano, Pablo

    1986-01-01

    Se correlacionan los resultados obtenidos en la valoración de bencidrilamina y derivados, a través de la utilización de tres métodos analíticos que emplean la extracción líquido-líquido y la cromatografía en capa fina como etapa preparativa, a los efectos de evitar la interferencia por parte de sustancias liberadas desde las membranas gástricas. Se observa buena concordancia de los valores medidos por espectrodensitometría y por espectrofotometría ultravioleta cuando se utiliza la cromatograf...

  4. ANÁLISE DO DESEMPENHO DE EMPRESAS DO SEGMENTO DE CARNES E DERIVADOS LISTADAS NA BM&FBOVESPA

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    Simone Sehnem

    2012-10-01

    Full Text Available O objetivo do trabalho consiste em analisar o desempenho econômico e financeiro das empresas frigoríficas que negociam ações na BM&FBOVESPA em uma série histórica que compreende um período de 5 anos. A fundamentação teórica resgata aspectos relacionados a internacionalização de empresas e estudos que relacionam internacionalização e desempenho. O trabalho foi desenvolvido por meio da utilização de dados das empresas do segmento de carnes e derivados, isto é, frigoríficos, disponibilizados no economática e que negociam ações na BM&FBOVESPA. No que diz respeito à forma de abordagem do problema, a presente pesquisa trabalha sob o enfoque quantitativo e classifica-se em uma pesquisa de cunho descritivo. Com relação aos procedimentos, classifica-se em uma análise de uma série histórica do desempenho econômico e financeiro das organizações de capital aberto pertencentes ao segmento de frigoríficos, o que permite fazer um diagnóstico dessas empresas. As contribuições desta pesquisa consistem em elucidar que ficou perceptível que as empresas lideres do setor, quais sejam JBS Friboi, BR Foods e Marfrig, em sua maioria ocupam a liderança nos indicadores de desempenho econômico analisados. São empresas que cresceram e se internacionalizaram nos últimos anos, aumentando o patrimônio, a estrutura produtiva e os rendimentos. Possuem maior capacidade de competir, por terem estruturas de escala e unidades industriais distribuídas nos diferentes continentes, o que lhes aufere ganhos em detrimento das empresas de porte menor. Conclui-se que a internacionalização impacta de maneira forte no desempenho das organizações analisadas no presente estudo

  5. Estudio toxicológico de un producto derivado de la caña de azúcar

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    Carmen Luisa García Rivero

    1997-08-01

    Full Text Available Se presentan los resultados obtenidos en la evaluación toxicológica preclínica de un principio activo formulado en crema con propiedades cicatrizantes y antifúngicas a partir de un producto natural derivado de la caña de azúcar, al cual se le determinó su inocuidad en animales de experimentación mediante la estimación de la dosis letal media en conejos F1 y ratas albinas Wistar, utilizando niveles de dosis elevados. También se estudió el potencial irritante sobre la piel, mucosa ocular, vaginal y rectal, así como su potencial como agente sensibilizante. De forma general los síntomas tóxicos observados no fueron significativos y desaparecieron en un período corto, no se presentó mortalidad y se comprobó la ausencia de efectos irritantes sobre la piel y mucosas evaluadas. Se demostró que el producto no es un agente sensibilizante. Los resultados obtenidos en el estudio realizado permiten clasificar al producto de una baja toxicidad.This paper reports on the results obtained from the preclinical toxicity assessment of an active ingredient formulated as a cream having healing and antifungal properties which was obtained from a natural product derived from sugar cane. The drug testing included the determination of its safety in experimental animals by the estimation of the mean lethal dose in rabbits F1 and albino Wistar rats using high dose levels. The potential irritancy on the skin, ophthalmic, vaginal and rectal mucosa was also studied, as well as the potential as a sensibilizing agent. Overall, the toxic symptoms observed were found to be no significant and they dissapeared within a short period of time. There was no mortality and the absence of irritant effects on the skin and mucosa was evidenced in the evaluation. It was proved that this product is not a sensibilizing agent. Results obtained from the study carried out allow to classify this product as having low toxicity levels.

  6. Uso de productos derivados de Bacillus thuringiensis como alternativa de control en nematodos de importancia veterinaria. Revisión

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    Alejandro Vázquez-Pineda

    2012-01-01

    Full Text Available La bacteria entomopatógena Bacillus thuringiensis produce cristales proteicos con actividad citotóxica en contra de insectos y nematodos. La toxicidad de B. thuringiensis en plagas agrícolas es ampliamente conocida, pero poco se conoce acerca de su actividad en contra de nematodos parásitos. Recientemente, la actividad nematicida de las proteínas derivadas de B. thuringiensis se demostró en parásitos de mamíferos como Haemonchus, Teladorsagia, Nippostrongylus, y Ancylostoma, y en nematodos de plantas, Globodera y Meloidogyne. Entre el grupo de B. thuringiensis con efecto nematicida, las proteínas de la cepa IB-16 han mostrado actividad letal de 50 a 100 % en contra de diferentes estadios del principal género de rumiantes, Haemonchus contortus. Asimismo, los géneros de nematodos de vida libre, Panagrellus redivivus y Caenorhabditis elegans han sido blanco de estudios de la acción nematicida de B. thuringiensis. Por ejemplo, el efecto tóxico de la proteína Cry5B de B. thuringiensis se observó en las células intestinales de C. elegans, además esta acción parece involucrar receptores celulares específicos, similares a los que se han notificado en contra de plagas agrícolas. Asimismo, la unión de la proteína Cry5B ocurre en receptores específicos, como moléculas de carbohidratos, las cuales están presentes en la membrana de las células de intestino de los nematodos, ocasionando daño y muerte. A través de este tipo de estudios, los derivados de B. thuringiensis podrían considerarse una alternativa de control en nematodos que afectan a los animales domésticos, como rumiantes, así como en contra de otros nematodos patógenos de mamíferos e incluso de plantas agrícolas.

  7. Benefícios à saúde humana do consumo de isoflavonas presentes em produtos derivados da soja

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    Mayara Miranda Zakir

    2015-09-01

    Full Text Available As leguminosas utilizadas na alimentação de diversas populações ao redor do mundo são importantes fontes de energia e diversos nutrientes. A soja (Glycine max que apresenta uma composição quase completa, vem se destacando como um alimento funcional, pois além de sua função normal de nutrição, ainda apresenta diversos benefícios para a saúde. O grão de soja possui os compostos bioativos que estão sendo amplamente estudados, pois visam a prevenção e a redução dos riscos de desenvolvimento de d oenças crônicas como diabetes, colesterol, hipertensão arterial, cânceres entre outros. As isoflavonas são compostos químicos pertencentes à classe dos fitoestrógenos, as principais isoflavonas encontradas na soja são a daidzeína, a genisteína e a gliciteína. Evidências científicas sugerem que as isoflavonas, desempenham um papel importante na prevenção e controle de doenças crônicas. Devido ao crescente interesse da população em consumir alimentos saudáveis, a indústria alimentícia vem se dedicando a desenvolver novos produtos, cujas funções pretendem ir além do fornecimento dos nutrientes básicos à alimentação humana, esses alimentos são conhecidos como alimentos funcionais. Dessa forma torna-se importante o estudo dos benefícios que o consumo de diferentes produtos alimentícios à base de soja pode oferecer na prevenção e no controle de diversas patologias. O presente trabalho tem como objetivo incentivar o consumo dos produtos derivados de soja, devido aos efeitos benéficos que a ação das isoflavonas presente na leguminosa oferece ao organismo humano.

  8. La biblioteca virtual especializada de los derivados de la caña de azúcar: consideraciones, experiencias y perspectivas

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    Hernández Curbelo, Maby

    2011-03-01

    Full Text Available In this paper, the results of a project for the design and implementation of a specialized virtual library for sugar cane by-products are presented, including initial considerations, an architecture for working in a web environment, and the basic characteristics of software for managing a digital collection. This library supports research into sugar cane by-products and also represents an initial step toward the creation of a specialized virtual centre of information and knowledge for the sugar industry.

    En este trabajo se describen los resultados del proyecto de diseño e implementación de la biblioteca virtual especializada sobre los derivados de la caña de azúcar. Se abordan consideraciones, arquitectura de trabajo en ambiente de Internet y características básicas del software para la administración de su colección digital. Esta biblioteca es soporte para la investigación sobre los derivados de la caña de azúcar y constituye el paso inicial hacia la creación de un centro virtual especializado de información y conocimiento para el sector azucarero.

  9. Efecto del derivado de la lactosa sobre la población microbiana de muestras fecales de cerdos posdestete

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    Rosero Olga Lucía

    2006-03-01

    Full Text Available COMPENDIO Se estudió el efecto prebiótico del derivado de la lactosa (DL en la población microbiana presente en las muestras de heces (inóculo fecal de los cerdos posdestete. Se utilizó la técnica de producción de gas in vitro en 2 sustratos: el control pulpa de remolacha (PR y DL. Se desarrollaron dos etapas. En la primera se determinó la producción del gas y las proporciones de ácidos grasos volátiles (AGV, evaluando la actividad microbiana en los niveles (0, 0.2, 2, 20 y 100% de DL reemplazando a la PR, durante la fermentación de 144h. El tiempo medio de la producción del gas potencial se alcanzó a las 12h de la fermentación. Este tiempo se utilizó para la segunda etapa con tres niveles de DL (0, 20 y 100%. Se determinó el efecto del DL sobre la composición de la población microbiana (E. coli, lactobacillus y anaerobios facultativos totales, concentración de AGV y sobre el pH, como resultado de la fermentación bacteriana . Se incrementó la concentración del butirato (P < 0.001 y la acidificación (P < 0.001 del medio. El DL modificó la composición microbiana, que se reflejó en la disminución (P < 0.001 del número de colonias microbianas de E. coli. En conclusión el DL en niveles altos presentó efectos prebióticos. Palabras claves: Lactosa, prebiótico, fermentación in vitro, cerdo, butirato, Escherichia coli ABSTRACT Effect of Lactose Derivative (LD on the present microbial populationʼs in the sample faeces of weaned piglets The pre­biotic effect of Lactose Derivative (LD on the present microbial populationʼs in the sample faeces (faecal inocula of weaned piglets was studied . The in vitro gas-production technique was used. Using 2 substrates: sugarbeet pulp (SBP as control and LD as evaluation. Two stages were developed. In the first it the gas production and the Volatile Fatty Acids (VFA proportions, during 144h fermentation, to evaluate the effect of the microbial activity with different

  10. Patulin: incidence and control in apple products / Patulina: incidência e controle em derivados de maçã

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    Crispin Humberto Garcia-Cruz

    2009-07-01

    Full Text Available The patulin, (4hydroxy-4furo[3,2-c]pyran(6H-1,, is a thermal resistent mycotoxin produced by several species of fungi are common in plants, mainly in derivatives and apples. Studies on the toxicity in animals have shown that mycotoxin has character teratogenic, and carcinogenic in mice immunotoxic. Its biosynthesis is well understood involving a series of reactions of condensation and oxiredução, many catalyzed by enzymes. The danger of contamination of food with patulin, warning about the need for a more rigorous control. Recent research aimed their removal and degradation as well as increase the sensitivity of the tests, making them faster and at less cost. The removal of patulin of food is made with composite adsorbents, with inconvenience to diminish the quality of the product by adsorbs other components desirable. The degradation is made with sulfur compounds, which are not allowed in food in many countries, and the growth of yeasts, such as the production of cider. Many yeasts have resistance against patulin and produce compounds capable degrade it. Here, we reviewed research on patulin with emphasis on its influence in food industry, incidence of patulin in apple juice and other foods, maximum permissible concentrations, health effects, biosynthesis, removal, degradation and most widely used methods for its detection and quantification.A patulina, 4hidroxi-4furo[3,2-c] pirano(6H-1, micotoxina termo-resistente, é produzida por várias espécies de fungos, comuns em vegetais, produtos derivados e principalmente em maçãs. Estudos sobre a toxicidade em animais demonstraram esta micotoxina possui caráter teratogênico, cancerígeno e imunotóxico em camundongos. Sua biossíntese é bem compreendida envolvendo uma série de reações de condensação e de oxiredução, muitas catalisadas por enzimas. O perigo da contaminação de alimentos com patulina, alerta sobre a necessidade de um controle mais rigoroso. Pesquisas recentes objetivam

  11. Evidencias espectroscópicas de RMN de ¹H y 13C en la formación inusual de un "carbonilo inorgánico", derivado de la lactona costunólida

    OpenAIRE

    Díaz, Eduardo; Barrios, Héctor; Fuentes, Aydeé; Corona, David; Guzmán, Ángel

    2002-01-01

    El uso de la RMN de ¹H y 13C permitió determinar la estructura inusual de un "carbonilo inorgánico" derivado de la lactona dehidrocostus. 1H and 13C NMR of an unusual "inorganic carbonyl" derived from costunolide lactone are described.

  12. Evolución del tipo de cambio peso mexicano/dólar estadounidense y el uso de derivados financieros

    OpenAIRE

    María de Lourdes Nájera López

    2013-01-01

    En este trabajo se analiza la evolución del tipo de cambio peso mexicano frente al dólar estadounidense, su volatilidad, así como el uso de los derivados financieros en las diferentes crisis que ha sufrido el país. Todo ello a partir de 1954 a la fecha, en donde se han registrado los regímenes de tipo de cambio: fijo, dual, de bandas de flotación y el de libre flotación. Se concluye que el tipo de cambio mexicano es volátil y que cualquier fenómeno económico o financiero externo repercute en ...

  13. Preparação regiosseletiva de derivados acilados da D-ribono-1,4-lactona empregando catálise enzimática

    OpenAIRE

    Sebrão, Damianni

    2011-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2011 Nesta tese foram desenvolvidas metodologias enzimáticas para a preparação regiosseletiva de derivados acilados da D-ribono-1,4-lactona. Os produtos foram identificados e quantificados por RMN-1H, UV-Vis ou titulação volumétrica com solução aquosa de KOH. Várias lipases, uma protease e dois micélios isolados de fungos da região amazôn...

  14. Síntesis y caracterización de nuevas nanopartículas de derivados de PBLG para su uso en nanomedicina

    OpenAIRE

    María Elisa Martínez Barbosa; An Young S. Taylor Castillo; Heriberto Acuña Campa; ian Arely Carrasco Cota

    2014-01-01

    En este trabajo se describe la realización de la síntesis y caracterización de cinco derivados de poli-L-glutamato de gamma-bencilo (PBLG) por polimerización aniónica de apertura de anillo utilizando iniciadores de interés biomédico, así como la preparación y caracterización de nanopartículas poliméricas preparadas usando los polímeros sintetizados. Los polímeros fueron caracterizados por resonancia magnética nuclear (RMN 1H) y cromatografía de exclusión de tamaño (GPC/SEC). Las nanopartícula...

  15. Complicações oculares da terapêutica com a cloroquina e derivados Ocular complications of chloroquine and derivatives therapy

    Directory of Open Access Journals (Sweden)

    Augusto Cézar Lacava

    2010-08-01

    Full Text Available INTRODUÇÃO: Os derivados das 4-aminoquinolonas vêm sendo utilizados desde sua industrialização na terapêutica da malária, das doenças reumatológicas e dermatológicas. Essas drogas apresentam reações adversas sistêmicas e oculares. As reações adversas sistêmicas afetam o sistema gastrointestinal, sistema nervoso, sistema muscular esquelético e a pele, e as oculares são: fotofobia, córnea verticilata, poliose, catarata, paralisia dos músculos extraoculares, uveíte anterior, maculopatia tóxica, neurite óptica. OBJETIVO: Revisão bibliográfica das complicações do uso de cloroquina e derivados. Analisar evolução e estágio atual da propedêutica. Sugerir conduta prática no mapeamento precoce dos sinais de toxicidade. MÉTODOS: Revisão bibliográfica através da pesquisa no banco de dados MEDLINE, PUBMED, LILACS e SciELO. DISCUSSÃO: São descritos todos os exames que podem ser utilizados para mapeamento das reações adversas oculares, tais quais: exame oftalmológico completo, com ênfase na biomicroscopia e oftalmoscopia binocular indireta, campo visual computadorizado, tela de Amsler, visão de cores, exames eletrofisiológicos, polarimetria e tomografia de coerência óptica. É feita a descrição do quadro de maculopatia enfocando epidemiologia, fatores de risco, histopatologia e propedêutica. É descrita a estrutura química e as diferenças entre os derivados das 4-aminoquinolonas. CONCLUS��O: Todo paciente em uso de cloroquina e seus derivados devem ser acompanhados e documentados desde seu início e até atingir a dose cumulativa acima de 100 gramas. Quanto maior a dose cumulativa, maior deve ser a nossa preocupação com o seguimento desse paciente.INTRODUCTION: Byproducts of 4-aminoquinolones are being used since its industrialization in the treatment of malaria, rheumatic and dermatologic diseases. These drugs present systemic and ocular adverse events. Systemic adverse reactions affect the

  16. 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®.

  17. Preferencias y frecuencia de consumo de derivados cárnicos por parte de estudiantes universitarios de Medellín, Colombia

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    Holmes Rodríguez-Espinosa

    2016-01-01

    Full Text Available Introducción: El consumo de derivados cárnicos en universitarios se ha venido incrementando en los últimos años, convirtiéndose en un factor de riesgo en esquemas de alimentación saludable, por lo cual es de vital interés por parte de los investigadores en las áreas de la salud y la nutrición, identificar las preferencias y frecuencia de consumo de estos productos para establecer estrategias de intervención.Material y Métodos: El tamaño de la muestra fue de 400 estudiantes, seleccionados aleatoriamente de acuerdo con los factores de ponderación: sexo, nivel socioeconómico y tipo de universidad, teniendo en cuenta un intervalo de confianza del 95% y un error máximo permisible del 5%. Los datos fueron analizados utilizando análisis multivariado de la varianza (MANOVA, análisis de comparación método Z.Resultados: Se encontró que el consumo de derivados cárnicos tiene una alta frecuencia y mayor preferencia de consumo en hombres (p=0,0139, en estrato bajo (p=0,0457 y en universidades públicas (p=0,0311.Conclusiones: El consumo de embutidos en universitarios es alto, especialmente en el sexo masculino, por lo cual se requiere implementar programas de educación sobre hábitos de consumo saludable.

  18. Micro-syntheses for the use of carbon 13 or carbon 14. Micro-preparations of methyl alcohol, methyl iodide, and sodium acetate labeled in the methyl group; Microsyntheses pour l'emploi de carbone 13 ou de carbone 14. Micropreparations d'alcool methylique, d'iodure de methyle et d'acetate de sodium marque sur le groupement methyle

    Energy Technology Data Exchange (ETDEWEB)

    Baret, C; Pichat, L

    1951-11-01

    Apparatus and technique are described in detail for (1) reduction of CO{sub 2} to CH{sub 3}OH with LiAlH{sub 4}, (2) conversion of the methanol to CH{sub 3}I by HI, (3) formation of the Mg Grignard reagent, and (4) addition of inactive CO{sub 2} to form CH{sub 3}COOH. All these operations have been carried out on 0.005 moles. Methyl-labeled Na acetate has been prepared in 67% yield based on the Ba{sup 14}CO{sub 3} used as starting material. (author) [French] Description detaillee d'une technique deja connue pour la reduction du gaz carbonique en alcool methylique par LiAlH{sub 4}. Conversion du methanol en iodure de methyle. Ce dernier transforme en reactif de Grigard, et carbonate, fournit de l'acide acetique. Toutes ces operations on ete effectuees sur 5 x 10{sup -3} moles. La methode a ete appliquee a la synthese d'acetate de sodium marque par le groupement methyle par {sup 14}C avec un rendement global de 67% base sur le carbonate de baryum radioactif mis en oeuvre. (auteurs)

  19. Économie d'un procédé d'hydrolyse enzymatique et fermentation de la paille de blé pour la production d'alcool carburant Economics of a Process for Producing Alcohol Fuels by Enzymatic Hydrolysis and Fermentation of Wheat Straw

    Directory of Open Access Journals (Sweden)

    Arlie J. P.

    2006-11-01

    Full Text Available Après définition des grandes lignes d'un procédé de base d'hydrolyse-fermentation de la paille de blé, l'analyse de sensibilité montre que le rendement de l'hydrolyse a une grande importance sur les bilans énergétique et économique. Des rendements de l'ordre de 85 % permettent d'obtenir des valeurs d'investissement par tonne de pétrole économisée tout à fait comparables à celles obtenues par d'autres techniques de valorisation de la biomasse en alcool, telle la synthèse du méthanol obtenu après gazéification du bois à l'oxygène. The basic features of a process for production from cereal straw of an acetone-butanol mixture for use as a gasoline substitute are described. They include pretreatment and enzymatic hydrolysis of the substrate followed by fermentation of the sugars produced. A cost evaluation based on the performances of a reference process is presented. Then, an analysis of the sensitivity of the cost price of the process to the variation of the important parameters such as production capacity, enzyme productivity, hydrolysis yield is carried out. The energy balance of the process is presented.

  20. Propuesta de juegos tradicionales derivados del béisbol en la comunidad. Estudio de caso: reparto Raúl Sánchez, Pinar del Río

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    Manuel Orlando Gutiérrez Jiménez

    2009-12-01

    Full Text Available Nuestro deporte nacional es uno de los que mas motivación muestra, sobre todo en los niños de todas las edades. Cada día en los espacios libres de nuestra comunidad vemos como los niños se reúnen para jugar Béisbol. Realizamos una investigación observacional y descriptiva, de todas las actividades que se desarrollaban dentro de los espacios libres de nuestra comunidad perteneciente al reparto ¨ Raúl Sánchez ¨ del municipio Pinar del Rio. En el tiempo libre la actividad recreativa de los niños se hacia monótona, desmotivada y mal orientada sin tener en cuenta los gustos, preferencias, espacio para la actividad, forma de pensar, de actuar sabiendo que esto es lo que hace que mejoren las relaciones interpersonales y la convivencia. Desde que se comenzó a jugar el Béisbol en nuestro país se fueron derivando variantes de juegos tradicionales los cuales se celebraban en los barrios por los niños imitando a las grandes estrellas de nuestro béisbol. Estas variantes se fueron traspasando de generación en generación haciendo cada una de ellas aportes y modificaciones pero sin perder el objetivo principal que sigue nuestro deporte nacional. De aquí es que nos dimos a la tarea de seleccionar varios juegos derivados del Béisbol en los cuales iban centradas las atenciones de nuestros niños, lo cual pudimos determinarlo a través de observaciones diarias, así como encuestas y entrevistas realizadas en la comunidad. Con los juegos tradicionales derivados del Béisbol ya sea por consecuencias de limitación de terrenos o por la falta de implementos debido al sanguinario bloqueo implantado por los Estados Unidos contra nuestro país hemos devuelto a nuestros niños la alegría de vivir, la posibilidad de sentirse verdaderos campeones dentro de su comunidad.

  1. Produção de anticorpos para cafeína e seu derivado cafeinidina Antisera production to caffeine and its derivative caffeinidine

    Directory of Open Access Journals (Sweden)

    P. MAZZAFERA

    1998-04-01

    Full Text Available São apresentados dados sobre a conjugação de cafeína e seu derivado cafeinidina com albumina de soro bovino e sua utilização para a produção de anticorpos. Galinhas poedeiras foram imunizadas e as globulinas extraídas das gemas dos ovos. Por ensaios de imunoprecipitação pode-se verificar que ambos anticorpos reagiram com seus respectivos antígenos, cafeína e cafeinidina. Também verificou-se que a posição do radical metil em mono e dimetilxantinas era importante para o reconhecimento antígeno-anticorpo. Metilação na posição N-3 pareceu ser determinante para o reconhecimento pelo anticorpo produzido para o conjugado cafeinidina-BSA. Por outro lado, metilação na posição N-7 foi importante para o conjugado cafeína-BSA. Discute-se as vantagens de um anticorpo sobre o outro e a possibilidade de seu emprego em testes imunológicos para determinação de alcalóides purínicos totais em material vegetal e seus derivados alimentícios.Data on the conjugation of caffeine and its derivative caffeinidine with bovine serum albumin and their use to produce antisera are reported here. Chickens were immunized with the conjugates and antisera were extracted from egg yolks. In immunoprecipitation assays it was verified that both antisera were efficient against their respective antigens. It was also observed that the methyl position in mono and dimethylxanthines played a role in the recognition by the antisera. Methyl at N-3 position seemed to be important for the precipitation by the antisera produced to caffeinidine-BSA conjugate. On the other hand, methylation at N-7 position was important for caffeine-BSA conjugate. The advantages of each antisera and their potential application in imunological tests as a tool to determine total purine alkaloids in plant material and derived foodstuffs are discussed.

  2. Biopéptidos en la leche y sus derivados: funcionamiento y beneficios a la salud / Bioactive peptides in milk and their derivatives: functionality and health benefits

    Directory of Open Access Journals (Sweden)

    Gabriela Rodríguez-Hernández

    2014-04-01

    Full Text Available La leche y los productos lácteos son fuente de proteínas de alto valor biológico. Algunas de éstas presentan actividades biológicas, nutricionales y funcionales en el ser humano. En los últimos años se ha reportado que los péptidos, derivados de las proteínas lácteas, son capaces de influir positivamente en la salud del consumidor. Sin embargo, éstos no ejercen beneficio alguno, más allá del aporte nutricional, cuando forman parte de las proteínas lácteas nativas, por lo que es necesario someter a las proteínas a procesos de hidrólisis enzimática. Este proceso puede llevarse a cabo por los microorganismos propios de la leche o por aquellos que son inoculados durante la elaboración y por la adición de enzimas comerciales utilizadas durante el procesado. Cabe señalar que el efecto hidrolítico no se limita a la elaboración de los productos lácteos, sino que continúa durante la maduración y la vida en el anaquel. Así mismo, diversas investigaciones han evidenciado que la actividad de las enzimas gastrointestinales es determinante en la hidrólisis que experimentan las proteínas lácteas. De tal forma que la liberación de los péptidos, aunada al tamaño, hidrofobicidad y secuencia de los mismos constituyen requisitos indispensables para convertirlos en péptidos con actividad biológica. Éstos últimos, también considerados como péptidos bioactivos o biopéptidos, han despertado recientemente el interés de los investigadores debido a que pueden influenciar favorablemente las funciones que llevan a cabo los sistemas inmune, gastrointestinal, nervioso y cardiovascular impactando la salud del consumidor. En esta revisión de literatura, se abordaron los mecanismos por los cuales son generados los biopéptidos derivados de proteínas lácteas y los efectos fisiológicos que producen.

  3. Fenóis derivados da lignina, carboidratos e aminoaçúcares em serapilheira e solos cultivados com eucalipto e pastagem

    Directory of Open Access Journals (Sweden)

    Rodinei Facco Pegoraro

    2011-04-01

    Full Text Available O cultivo de espécies florestais como o eucalipto em solos ocupados por pastagens pode levar a alterações no processo de decomposição de resíduos vegetais e na formação da matéria orgânica do solo (MOS, principalmente por alterar a contribuição de diferentes compostos orgânicos e modificar a atividade e a diversidade microbiana. Neste sentido, o presente estudo teve o objetivo de avaliar alterações causadas pelo cultivo do eucalipto em compostos orgânicos, tais como: fenóis derivados de lignina, carboidratos e aminoaçúcares, visando identificar o estádio de decomposição e a contribuição de compostos de origem microbiana para a MOS em solos do litoral Norte do Espírito Santo em comparação àqueles de pastagem. Os resultados indicaram menor aporte de carboidratos e teor de lignina similar na serapilheira de eucalipto em comparação àqueles da pastagem. Os fenóis derivados de lignina, que se caracterizaram pela presença de compostos do grupo cinamil (ácidos ferúlico e p-coumárico em maior teor, refletiram em maior acúmulo destes compostos e carboidratos totais no solo de pastagem, embora os teores totais de lignina, COT, NT e aminoaçúcares tenham sido semelhantes entre os cultivos. Nos solos cultivados com eucalipto obteve-se maior contribuição de componentes de origem vegetal (menor relação H/P para a MOS que aqueles de origem microbiana em comparação aos solos sob pastagem. O teor de determinados aminoaçúcares, como a glucosamina, nos solos indicou que os fungos são mais abundantes que bactérias e actinomicetos, especialmente no solo de pastagem.

  4. Silício alterando compostos derivados da pirólise de bainhas foliares de plantas de arroz infectadas por Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Daniel Augusto Schurt

    Full Text Available Este trabalho teve como objetivo elucidar, por meio da pirólise analítica acoplada à cromatografia gasosa e espectrometria de massa, alterações na composição química da lignina nas bainhas de plantas de arroz das cultivares BR-Irga 409 e Labelle supridas ou não com silício (Si e infectadas por Rhizoctonia solani. A concentração de Si nas bainhas das plantas supridas com esse elemento foi significativamente maior (2,7 dag kg-1 em comparação com as plantas não supridas (0,45 dag kg-1. Na presença de Si, a área abaixo da curva do progresso da queima das bainhas foi significativamente reduzida em 19 e 25%, respectivamente, para as plantas das cultivares BR-Irga-409 e Labelle em relação à ausência desse elemento na solução nutritiva. Com base nos espectros de massas obtidos, foram identificados 33 compostos, dos quais 10 foram produtos da degradação de carboidratos e 23 derivados da lignina. Dentre os derivados da lignina, oito compostos eram do tipo p-hidroxifenila, 11 compostos do tipo guaiacila e quatro compostos do tipo siringila. Nas bainhas das plantas das duas cultivares de arroz, supridas ou não com Si, a concentração de lignina (p-hidroxifenila, siringila (S e guaiacila (G foi de, aproximadamente, 15%. Houve aumento na relação S/G apenas nas bainhas das plantas da cultivar BR-Irga 409 supridas com Si e infectadas por R. solani. A maior concentração de Si nas bainhas das plantas de arroz das duas cultivares, que por sua vez resultou em aumento na relação S/G, contribuiu para reduzir os sintomas da queima das bainhas.

  5. Electrosíntesis y caracterización de materiales moleculares a partir de derivados n-trifluorometansulfonil-1-azahexa-1,3,5-trienos.

    Directory of Open Access Journals (Sweden)

    M. E. Sánchez Vergara

    2008-01-01

    Full Text Available Actualmente existe un interés creciente en los Materiales Moleculares, ya que estos pueden presentar diferentes comportamientos eléctricos que van desde aislantes, semiconductores o bien conductores. En el presente estudio fueron sintetizados materiales de este tipo, a partir de derivados N-Trifluorometansulfonil-1-azahexa-1,3,5-trienos y K3[Cr(C2O43]•3H2O debido a que estos compuestos representan un gran interés por sus variadas aplicaciones en campos como la química analítica, además los derivados N-Trifluorometansulfonil-1-azahexa-1,3,5-trienos resultan especialmente atractivos desde el punto de vista estructural ya que en su forma neutra presentan una extensa deslocalización electrónica lo cual les confiere un comportamiento químico muy particular. En esta comunicación, se forman mediante electrosíntesis convencional y mediante electrosíntesis en el módulo de electrocristalización del microscopio de fuerza atómica (AFM, algunos materiales moleculares. Una vez obtenidos dichos materiales, se caracterizan por análisis elemental sobre superficies (SEM-EDS.Recently, molecular materials have been developed because of their electrical properties which give conductor, semiconductor, or superconductor behaviour. In this work, the synthesis of new materials formed from Ntrifluoromethanesulfonyl-1-azahexa-1, 3, 5-triene species and K3[Cr(C2O43]•3H2O is reported. NTrifluoromethanesulfonyl-1-azahexa-1,3,5-trienes compounds, which are highly functionalised pentametines, have also been studied due to its interesting physical and chemical properties. These compounds are especially interesting from a structural point of view for some reasons; in a neutral form, they show an extensive electronic delocalisation, which confers them a very particular chemical behaviour. This study is focused on the Molecular Materials preparation by means of two different electrosynthesis techniques: electrocrystallization in conventional cells, and

  6. Teores de colesterol e oxidação lipídica em hambúrguer bovino com adição de linhaça dourada e derivados

    Directory of Open Access Journals (Sweden)

    Daiana Novello

    2013-07-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da adição de linhaça‑dourada e derivados sobre os teores de colesterol e a oxidação lipídica em hambúrguer bovino. Foram elaborados hambúrgueres com 5,0% de óleo, ou farinha, ou sementes de linhaça‑dourada, além de uma formulação‑controle (sem adição de linhaça ou derivados. Os hambúrgueres foram mantidos congelados, a ‑18ºC, por 90 dias. Determinou-se o teor de colesterol e a estabilidade oxidativa dos produtos crus e grelhados. Os menores teores de colesterol foram observados nos produtos com óleo de linhaça. No entanto, a adição de linhaça e derivados aumentou a oxidação lipídica em hambúrguer bovino (maiores valores de malonaldeído, após o armazenamento.

  7. Antiplasmodial activity of 3-trifluoromethyl-2-carbonylquinoxaline di-N-oxide derivatives Atividade antimalárica de derivados di-N-óxido de 3-trifluorometil-2-carbonilquinoxalina

    Directory of Open Access Journals (Sweden)

    Belén Zarranz

    2006-09-01

    Full Text Available The in vitro antiplasmodial activity of some 3-trifluoromethyl-2-carbonylquinoxaline di-N-oxide derivatives is reported. The evaluation was performed on cultures of FcB1 strain (chloroquine-resistant of P. falciparum and the most interesting compounds were then evaluated on MCF7 tumor cells in order to evaluate an index of selectivity. The 7-methyl (2b, 4b, 5b, 6b and nonsubstituted (3c, 4c, 5c quinoxaline 1,4-dioxide derivatives presented the best level of activity.Neste artigo descreve-se a atividade anti-Plasmodium falciparum de derivados 3-trifluorometil-2-carbonilquinoxalinas di-N-óxidos (2a-6g. A avaliação das propriedades farmacológicas dos derivados 2a-6g foi realizada em modelo in vitro de inibição de cepas P. falciparum FcB1 (cloroquina resistente em cultura celular, e sobre culturas de células tumorais MCF7, com a finalidade de estabelecer o índice de seletividade para os compostos mais promissores. Os derivados 7-metil (2b, 4b, 5b, 6b e não-substituído (3c, 4c, 5c apresentaram o melhor perfil de atividade.

  8. Adsorption de l'eau dissoute dans les mélanges supercarburant-alcools en vue de leur stabilisation. Comparaison entre adsorbants classiques et résines échangeuses d'ions Adsorption of Dissolved Water in Premium-Fuel/Alcohol Blends with a View to Their Stabilization. Comparison Between Conventional Adsorbents and Ion-Exchange Resins

    Directory of Open Access Journals (Sweden)

    Bernasconi C.

    2006-11-01

    Full Text Available Une réponse possible au problème de la déstabilisation par démixtion des mélanges supercarburant-alcools est l'abaissement de leur teneur en eau par adsorption physique. La forte affinité pour l'eau des résines échangeuses d'ions de type polystyrène sulfonate permet d'envisager leur utilisation dans ce cas spécifique d'application. Le principal intérêt de ce nouveau matériau adsorbant est de pouvoir se régénérer avec des calories de bas niveau (100-120°C. Nous avons donc étudié, du point de vue capacité d'adsorption et cinétique d'adsorption, le comportement de cet adsorbant et comparé ses performances à celles d'adsorbants plus classiques tels que le silicagel, l'alumine et le tamis moléculaire 3 Å. Les formes ioniques de la résine mises en oeuvre sont les formes : K+, Na+ et Mg2+. Sur le plan de la capacité totale d'adsorption, la résine, quelle que soit sa forme ionique, présente des performances supérieures à celles de l'alumine et du silicagel. Seule la forme Mg2+ adsorbe autant d'eau que le tamis moléculaire. L'efficacité de la résine est sensible à la nature de l'alcool du mélange considéré et augmente selon la séquence méthanol A possible answer to the problem of destabilization by the segregation of premium-fuel/alcohol blends lies in decreasing their water content by physical adsorption. The strong affinity of water for ion-exchange resins of the polystyrene sulfonate type suggests their use for this specific application. The main advantage of this newadsorbent material is that it can be regenerated with low-level heat (100-120°C. We thus investigated the behavior of this adsorbent from the standpoint of its adsorption capacity and adsorption kinetics. Its performances were compared to those of more conventional adsorbents, such as silicagel, alumina and a 3Å molecular sieve. The ionic forms of the resin used are in the form of K+, Na+ and Mg2+. From the standpoint of total adsorption capacity

  9. Síntesis y caracterización de nuevas nanopartículas de derivados de PBLG para su uso en nanomedicina

    Directory of Open Access Journals (Sweden)

    María Elisa Martínez Barbosa

    2014-06-01

    Full Text Available En este trabajo se describe la realización de la síntesis y caracterización de cinco derivados de poli-L-glutamato de gamma-bencilo (PBLG por polimerización aniónica de apertura de anillo utilizando iniciadores de interés biomédico, así como la preparación y caracterización de nanopartículas poliméricas preparadas usando los polímeros sintetizados. Los polímeros fueron caracterizados por resonancia magnética nuclear (RMN 1H y cromatografía de exclusión de tamaño (GPC/SEC. Las nanopartículas fueron preparadas por nanoprecipitación y caracterizadas por microscopía electrónica de transmisión (MET y dispersión de luz (DLS/DDLS. Como se requiere para aplicaciones en nanomedicina, nanopartículas en el intervalo de 20 a 50 nm fueron obtenidas. Por otro lado, se presenta la técnica de dispersión de luz depolarizada (DDLS, como una técnica interesante para la caracterización morfológica y comportamiento dinámico de las nanopartículas poliméricas, en suspensión acuosa.

  10. Aportes teóricos derivados de las investigaciones sobre el lenguaje entre el 2000 y el 2010: una revisión

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    Johny Villada Zapata

    2012-01-01

    Full Text Available El artículo presenta el análisis de contenido derivado de una revisión sistemática en la que se retomaron 57 estudios que tenían el lenguaje como tema central. Las investigaciones consultadas arrojan diversos aportes teóricos de los cuales sobresale, en primer lugar, el origen social de este proceso, tanto en la filogénesis como en la ontogénesis. En segundo lugar puede afirmarse que su desarrollo se ve afectado negativa o positivamente por variables como la nutrición, la relación con los padres, la socialización en la escuela y el ambiente social. Finalmente, la investigación con bebés muestra su participación activa en el reconocimiento del idioma, el acto de señalar como un hito importante en el desarrollo del lenguaje al provocar la atención conjunta y, finalmente, la relación existente entre el lenguaje y teoría de la mente.

  11. AVALIAÇÃO DA COMPOSIÇÃO CENTESIMAL, DIGESTIBILIDADE E ATIVIDADE INIBITÓRIA DE TRIPSINA EM PRODUTOS DERIVADOS DE SOJA (GLYCINE MAX

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    L. I. BERNO

    2008-11-01

    Full Text Available

    O trabalho teve como objetivo comparar produtos comerciais à base de soja, com grãos de soja orgânica cozidos, quanto à composição centesimal, digestibilidade de proteína e atividade inibitória de tripsina. Os produtos testados foram proteína texturizada de soja, substitutos cárneos e bebidas à base de soja, sendo avaliadas a composição centesimal, a digestibilidade de proteína e a atividade inibitória de tripsina. Os resultados foram expressos em base seca e realizado teste de Tukey (p= 0,05 para diferenças entre médias. Os produtos analisados apresentaram composição nutricional muito diferenciada em relação ao grão integral e alta digestibilidade de proteínas. A quantidade de inibidores de tripsina para os produtos em geral foi baixa, indicando que este fator antinutricional não tem importante infl uência nestes produtos. Pode-se concluir que, embora todos sejam produtos derivados de soja, há variação na quantidade de nutrientes disponíveis, devido ao tipo de processamento e adições realizadas.

  12. Perfil do consumo de leite e produtos derivados na cidade de Maringá, Estado do Paraná = Profile of milk and its products consumption in Maringá, Paraná State

    Directory of Open Access Journals (Sweden)

    Gustavo Molina

    2010-07-01

    Full Text Available Os dados coletados na cidade de Maringá, Estado do Paraná, referentes ao consumo e à aceitação do leite e seus derivados foram utilizados para se traçar o perfil do consumo desses produtos, gerando subsídios para entendimento mais amplo sobre o mercado consumidor de leite. Trezentos indivíduos responderam à pesquisa que avaliou o grau de aceitação e frequência de consumo do leite e produtos derivados. Observou-se que o mais importante para o consumidor, no momento da compra, encontra-se na relação entre preço e qualidade do produto, e aproximadamente metade dos entrevistados (48,17% tem preferência pelo leite integral, seguido pelo desnatado com 26,20%. Entretanto,constatou-se que 8,73% dos entrevistados declararam não consumir leite, e a maior parte dos casos justifica-se por possuírem algum nível de intolerância à lactose. Enquanto isso, o iogurte e os queijos foram apontados como os derivados com maior percentual defrequência de consumo e aceitação. De forma geral, os dados coletados permitem concluir que o leite e seus derivados são produtos consumidos com regularidade e seus derivados foram apontados com alto percentual de frequência de consumo e aceitação.Data collected in Maringá, Paraná State, on the acceptance and consumption of milk and its products were used to delineate the profile of consumption of these products, generating benefits for a better understanding of the consumer market for milk. A total of 300 people answered the survey that assessed the degree of acceptance and frequency of consumption of milk and its products. It was observed that the most important to the consumer at the time of purchase, is the relationship between price and quality of product, and approximately half of respondents (48.17% prefer whole milk, followed by skimmed milk with 26.20%. However, it was found that 8.73% of respondents reported that do not consume milk, with the majority of cases justified by some level of

  13. Riesgos y daños a la salud derivados del uso de videoterminal Health hazards associated with the use of video display terminals

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    Silvia Tamez González

    2003-06-01

    Full Text Available OBJETIVO: Evaluar la relación de daños a la salud con el uso de videoterminal, riesgos laborales y factores psicosociales en trabajadores de un diario informativo. MATERIAL Y MÉTODOS: En 1998 se estudió una muestra representativa (n=68 de una población de 218 trabajadores de un diario informativo de la Ciudad de México. Se presentan los resultados obtenidos a partir de una encuesta de autoaplicación, los cuales fueron comparados posteriormente con datos de exámenes clínicos. La hipótesis de esta investigación sustenta que, tanto el uso actual como la exposición acumulada de videoterminal, se asocian con mayor riesgo de presentar padecimientos visuales, músculo-esqueléticos y dermatológicos; trastornos mentales y psicosomáticos, y fatiga general. Los resultados fueron analizados en función de diferentes riesgos laborales: (riesgo visual, trabajo sedentario, uso de mouse, riesgo postural, calor excesivo y hacinamiento y factores psicosociales derivados de la organización del trabajo (demandas psicológicas, control sobre el trabajo y apoyo social. Para valorar su relación con los daños derivados del uso de videoterminal, se estimaron razones de prevalencias ajustadas por confusores potenciales (edad, sexo y escolaridad. RESULTADOS: Las mujeres presentaron prevalencias más elevadas de trastornos músculo-esqueléticos en la mayoría de los daños investigados, y las diferencias fueron significativas entre ambos sexos para dermatitis y eczema seborreico. El uso de videoterminal se asoció con mayor riesgo de fatiga neurovisual, trastornos músculo-esqueléticos en manos y extremidades superiores, dermatitis y eczema seborreico. De los riesgos laborales, los más asociados con trastornos fueron el uso de mouse y el riesgo postural. Los factores psicosociales se relacionaron principalmente con los padecimientos de naturaleza psicológica (trastornos mentales, psicosomáticos y fatiga general. CONCLUSIONES: Con el uso intensivo de

  14. La penicilina y sus derivados como agentes desencadenantes de la respuesta inmune Penicillin and its derivatives as immune response unleashing agents

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    Yulién Alpízar Olivares

    2000-08-01

    Full Text Available Con el uso de la penicilina y sus derivados aparecen comúnmente reacciones de hipersensibilidad. Con el fin de caracterizarlas, se estudia la estructura química de estos antibióticos y su influencia en dichas reacciones. Existen factores que pueden predisponer al desarrollo de estos efectos adversos, entre los que se encuentran la gran heterogeneidad en la restricción por el sistema principal de histocompatibilidad (SPH, el fenotipo de los clones celulares reactivos a estas drogas y el patrón de citocinas que se liberan. Todo lo anterior da origen al cuadro clínico tan diverso que exhiben las reacciones causadas por estos fármacos. La profundización en el conocimiento de los mecanismos que condicionan estas respuestas constituye un reto para los investigadores en el campo de la inmunologíaThe use of penicillin and its derivatives very often brings about hypersensitivity reactions. To characterize them, we studied the chemical structure of these antibiotics and their influence on such reactions. There are factors that may predispose people to the development of these adverse reactions, among them are the great heterogeneity in restriction by the main histocompatibility system, the phenotype of reactive cell clones to these drugs and the pattern of cytokines that are released. All the above-mentioned gives rise to the so diverse clinical picture of the reactions caused by these drugs. Widening of knowledge on mechanisms leading to these reactions becomes a challenge for researchers in the field of immunology

  15. La Caña de Azúcar y sus Derivados en la Huasteca San Luís Potosí México

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    Noé Aguilar Rivera

    2011-08-01

    Full Text Available La caña de azúcar es el principal cultivo de México, su cosecha se lleva a cabo en 665,000 ha que ocupan a 2.5 millones de personas. Existen 57 ingenios azucareros localizados en 15 estados de la republica. La industria ha cambiado dramáticamente desde la introducción de la caña de azúcar hace 486 años (año 1523 y su situación es reflejo de su metamorfosis y de intereses económicos y políticos. Fueron los españoles quienes introdujeron la caña de azúcar y tomaron así ventajas de las condiciones favorables que México ofrecía para el cultivo y la comercialización de los productos de derivados de la caña de azúcar (melazas, azúcar, panela o piloncillo y aguardiente. Grandes plantaciones fueron establecidas en diversas áreas como la Huasteca Potosina (San Luis Potosí. Esas plantaciones modificaron no solo las condiciones de vida, además la constitución de cada una de esas sociedades. El cambio fue dramático debido a la gran cantidad de indígenas nativos y al interés de los españoles hacia otras mercancías como los minerales y otros cultivos. En este trabajo se presentan algunos aspectos de la evolución y las estrategias para el desarrollo de la industria azucarera en la Huasteca Potosina San Luis Potosí durante el Virreinato de Nueva España.

  16. Evaluación antimicrobiana de 4 productos derivados del ácido piroleñoso para su posible utilización como desinfectantes

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    Miriam Concepción Rojas

    1997-12-01

    Full Text Available Se evaluó la efectividad antimicrobiana de 4 productos derivados del ácido piroleñoso (LQ 501-10, LQ 501-20, LQ 502-10 y LQ 502-20, según la metodología CAME. Los 4 productos tienen buena efectividad antimicrobiana a la concentración del 6 %. El estudio práctico en áreas quirúrgicas mostró una gran reducción de unidades formadoras de colonias después de la desinfección. En el estudio toxicológico se aprecia que los 4 productos son aptos para el uso propuesto. Se recomienda su utilización como desinfectantes de superficie (paredes, pisos, mesetas, etcétera, además pueden emplearse como limpiador. Los 4 productos formulados se pusieron en práctica y se incluyeron en el Registro de Productos Sanitarios.It is evaluated the antimicrobial effectiveness of 4 products derived from the pyroligneous acid (LQ 501-10, LQ 501-20, LQ 502-10, and LQ 502-20, according to the CMEA methodology. The 4 products have a good antimicrobial efficiency at a concentration of 6 %. The practical study in surgical areas showed a great reduction of those units forming colonies after disinfection. According to the toxicological study, the 4 products are suited to their purposes. It is recommended their use as surface disinfectants (walls, floors, counters, etc.. They can also be used as cleaners. These four products were put into practice and included in the Register of Sanitary Products.

  17. Instituto de productos lácteos y derivados grasos del P.J.C. Arganda – España

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    Ruiz Duerto, A.

    1973-09-01

    Full Text Available This article describes. a The CLUB-DINING-ROOM, made up of: premises for different uses, kitchen, air conditioning installation, semi-basement, stores, covered porch and covered tennis court, which can be reached from outside. Metal structure, ceramic forging and enclosures of silicocalcareous brick. b The LABORATORY BUILDING for the Institute of Dairy Products and By-Products comprises: semibasements, for plant, workshop, changing rooms, stores and other services; first floor: for direction, management, hali, board room, library and laboratory; two floors of laboratories. The structure is metal in girders and pillars, forming a three-dimensional main network —vertically and horizontally— allowing thé passage of any duct. The upright projections which undergo solar action are protected by vertical and horizontal sunbreakers which give the building a most unusual appearance.Se describen en este artículo: a El CLUB-COMEDOR, compuesto de: local para distintos usos, cocina, instalación de acondicionami¿nto de aire, semisótano, almacén, porche cubierto y campo de tenis en la cubierta, con acceso exterior. Estructura metálica, forjados cerámicos y cerramientos de ladrillo silicocalcáreo. b El EDIFICIO DE LABORATORIOS para el Instituto de Productos Lácteos y Derivados Grasos, consta de semisótano: para instalaciones, taller, vestuarios, almacén y otros servicios; planta primera: de dirección, administración, aula, juntas, biblioteca y laboratorio; dos plantas de laboratorios. La estructura es metálica en vigas y pilares, constituyendo una red principal tridimensional —en vei-tical y en horizontal— que permite el paso de cualquier conducto. Los alzados que sufren la acción solar están protegidos por córtaseles verticales y horizontales que prestan una fisonomía singular al edificio.

  18. Características físico-químicas de derivados proteicos de soja em dietas extrusadas para cães Physical-chemical characteristics of soy-protein derived in extruded diets for dogs

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    Ananda Portella Félix

    2010-12-01

    Full Text Available A soja é um grão rico em proteínas e lipídeos, a partir do qual se obtém diversos derivados proteicos de alto valor nutricional. Em virtude disso, realizou-se este estudo com o objetivo de analisar a composição bromatológica de derivados proteicos de soja, bem como as características físico-químicas dos extrusados formados a partir destes. Foram formuladas seis dietas para cães, uma referência e cinco contendo 30% de derivados de soja (farinha desengordurada - FDS, micronizada, farelo, grão integral e grão tostado, as quais foram extrusadas. Os derivados de soja e as dietas foram submetidos a análises bromatológicas e de qualidade do processamento. A FDS e o farelo de soja apresentaram os maiores teores de proteína bruta, enquanto os grãos de soja integral e tostado e a soja micronizada apresentaram os maiores teores de extrato etéreo em hidrólise ácida e energia bruta. A soja grão integral apresentou a maior atividade ureásica e inibitória de tripsina, mesmo após a extrusão da dieta. Os extrusados contendo as sojas grão e micronizada apresentaram as maiores densidades e as menores durezas, índice de absorção de água e grau de gelatinização do amido. Derivados proteicos de soja apresentam alto valor nutricional, entretanto, devem ser termicamente processados antes da extrusão para completa inativação do inibidor de tripsina. Além do mais, derivados contendo alto teor de lipídeos, como soja grão e micronizada, quando adicionados em 30% da fórmula, comprometem a qualidade do extrusado.Soy is a grain rich in protein and lipids, from which its obtained different protein products of high nutritional value. This study aimed to analyze the chemical composition of different soy-protein products, as well as the characteristics of the extruded produced. Six diets were formulated, a reference and five with 30% soy product (defatted soy flour - DSF, micronized, soybean meal, crude grain or toasted grain, which were

  19. Evaluación financiera de proyectos de emprendimiento derivados de resultados de investigación como paso para la creación de empresas de base tecnológica

    OpenAIRE

    Jaime Tobón, Juan Manuel

    2012-01-01

    El presente trabajo busca entender las diferencias entre una evaluación financiera de un proyecto y uno de emprendimiento derivado de resultados de investigación, como base para la creación de empresas de base tecnológica. Para ello se construyen las bases conceptuales sobre este tipo de empresas y la evaluación financiera de proyectos, como parte integral para la elaboración de un modelo o plan de negocio de un emprendimiento. A partir de estos conceptos, y considerando algunas condiciones d...

  20. ALTERACIONES EN EL FUNCIONAMIENTO COGNITIVO EN UNA MUESTRA DE NIÑOS, NIÑAS Y ADOLESCENTES CON TRASTORNO DE ESTRÉS POSTRAUMÁTICO DERIVADO DEL CONFLICTO ARMADO EN COLOMBIA

    OpenAIRE

    Barrera-Valencia, Mauricio; Calderón-Delgado, Liliana; Aguirre-Acevedo, Daniel Camilo

    2017-01-01

    Resumen El objetivo del presente estudio fue comparar el perfil de funcionamiento cognitivo de una muestra de niños, niñas y adolescentes con Trastorno de Estrés Postraumático (TEPT) derivado del conflicto armado en Colombia con un grupo de control. La muestra estuvo conformada por 50 participantes: 25 de ellos con TEPT, víctimas de situaciones asociadas a conflicto armado y 25 provenientes de la misma zona geográfica sin antecedentes de haber vivido tales situaciones. Los grupos fueron equip...

  1. DETERMINACIÓN DE FENOLES TOTALES EN DERIVADOS LÍGNICOS OBTENIDOS DEL “LICOR NEGRO” COMO ALTERNATIVA DE PRODUCCIÓN // DETERMINATION OF TOTAL PHENOL DERIVATIVES OBTAINED FROM LIGNIN "BLACK LIQUOR" AS ALTERNATIVE TO PRODUCTION

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    María José López Villalobos

    2015-06-01

    derivados lignicos obtenidos empleando el método de Folin-Ciocalteu. En el proceso de Sulfito el derivado lígnico extraído con ácido acético contiene mayor cantidad de fenoles, y en el proceso de Kraft, el derivado lignido extraido con ácido nítrico presentó menor cantidad. La cantidad de fenoles totales presentes en estos derivados es buena, pudiendo aprovecharse en la elaboración de antisépticos, detergentes, nylon, resina y múltiples productos industria Palabras clave: Lignina, desecho, precipitación, fenoles, antioxidantes.

  2. Excreción de derivados de purinas en función de la relación fibra/proteína en la dieta de Alpacas (Vicugna pacos)

    OpenAIRE

    Rúa M, Viviana; Olazábal L, Juan; San Martín H, Felipe

    2017-01-01

    El objetivo del presente estudio fue evaluar la relación de la fibra detergente neutro/proteína cruda sobre la excreción urinaria de derivados de purinas (DP) en alpacas. Eldiseño experimental fue un cuadrado latino 3x3. Se utilizaron tres alpacas Huacaya machos de 2.5 años de edad, confinados en corrales individuales. El alimento fue suministrado una vez al día y con agua ad libitum. Se trabajó con tres tratamientos a base de heno de avena, donde las relaciones de fibra/proteína se obtuviero...

  3. ¿Es el Tamaño de una Entidad de Crédito Factor Determinante de los Resultados Derivados de su Gestión?

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    A. Javier Pérez García

    1999-12-01

    Full Text Available El objeto del trabajo se concreta en contrastar si la dimensión de una entidad de crédito es o no una variable determinante de la gestión empresarial. Para ello efectuamos un análisis estático transversal referido al ejercicio 1995, efectuando un análisis financiero riguroso e individualizado para 93, crédito españolas. Una vez identificados los factores determinantes de los resultados de la gestión empresarial, pasamos a estudiar el grado de relación entre las variables explicativas y explicadas, para terminar estableciendo una tipología de entidades en función de sus modelos de gestión aplicando diversas técnicas de análisis multivariable. El trabajo pone de manifiesto que el tamaño de una entidad de crédito no es un factor determinante de los resultados de la gestión. Asimismo detectamos la existencia de cinco modelos de gestión di firmándose que, desde un punto de vista técnico, una dimensión mayor no garantiza mejore derivados de la gestión de la entidad. No obstante, no podemos obviar que existen razones, e ponente político importante, que anteponen el crecimiento al logro de una rentabilidad ad dimensión. The objective of the article is to contrast if the size of a financial entity is a determining variable, in its performance measurement. To demonstrate this, we have carried out a static cross analysis, in relation exercise for 1995, performing a thorough and individual financial analysis on 93 Spanish financial entities. Once the determining factors of the performance measurement have been identified, we go the level of relation between variables in order to determine a class of entities in terms of their performance measurement applying multivariable analysis techniques. The study draws attention to the fact that the size of the financial entities is not a determining performance measurement. We detect the existence of five different performance models, confirming from a technical point of view, a greater

  4. Avaliação ergonômica de cadeiras de madeira e derivados Ergonomic evaluation of chairs made of wood and its derivatives

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    Amaury Paulo de Souza

    2010-02-01

    Full Text Available Este trabalho teve como objetivo realizar a avaliação ergonômica de cadeiras de madeira e derivados fabricadas no Polo Moveleiro de Carmo do Cajuru, MG, visando à melhoria da qualidade ergonômica dos móveis, envolvendo aspectos de adaptação antropométrica, conforto e de segurança. A coleta de dados foi realizada em cadeiras fabricadas por indústrias associadas ao Sindicato das Indústrias do Mobiliário e de Artefatos de Madeira no Estado de Minas Gerais de Carmo do Cajuru - SINDIMOV, MG. Os critérios de conformidade foram definidos de acordo com os princípios de antropometria, ergonomia e os aspectos de segurança para o usuário. Os resultados das medições foram confrontados com recomendações e dados antropométricos existentes na literatura. Observou-se que os maiores problemas detectados nas cadeiras estavam relacionados às dimensões do assento. A altura dos assentos de todas as cadeiras foi superior aos valores recomendados na literatura. Os encostos não apresentaram problemas quanto à sua largura, porém necessitavam de adequação dos ângulos de inclinação em relação aos assentos. Outro problema encontrado foi a grande incidência de quinas e bordas retas que podem ocasionar injúrias aos usuários desses móveis.This study aimed to carry out an ergonomic assessment of chairs and wooden products manufactured in the furniture cluster of Carmo do Cajuru, MG, and improve the ergonomic quality of furniture, involving aspects of anthropometric adaptation, comfort and safety. Data were collected from chairs manufactured by industries associated with the Union of Furniture Industries and Wooden Artifacts located in Carmo do Cajuru in the State of Minas Gerais - SINDIMOV, MG. Compliance criteria were defined according to the anthropometric principles, aspects of ergonomics and safety for the user. Measurements were compared with anthropometric data and recommendations in the literature. The major problem identified in

  5. El médico del trabajo en el control del uso de equipos de protección individual y los problemas de la salud derivados

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    Susana Lastras González

    2008-09-01

    Full Text Available En este trabajo proporcionaremos la información disponible sobre los equipos de protección individual (EPIs como parte importante de nuestra labor como médicos del trabajo. Todos los trabajadores están expuestos a una serie de riesgos, la mayor parte de ellos prevenibles de forma colectiva, pero en algunas ocasiones, estas medidas no llegan a ser del todo eficaces por lo que son necesarios equipos de protección individual. Estos equipos están destinados a ser llevados o sujetados por los trabajadores para protegerles de los riesgos que puedan amenazar su seguridad o su salud en el ámbito del trabajo, pero sin embargo, son capaces por sí mismos de crear efectos indeseables en la salud de los trabajadores, derivados de su uso. Por este motivo, los médicos del trabajo deben vigilar la salud de los trabajadores, valorando sus factores personales que puedan dificultar el uso de EPIs, informar y formar a los trabajadores sobre todo lo relativo al uso de los mismos, elegir el EPI adecuado para cada trabajador y, sobretodo, realizar un seguimiento para detectar posibles efectos indeseables del uso de EPIs y así evitar la no utilización y, por tanto, la ineficacia del EPI.In this study will provide information on personal protective equipment (PPE as an important part of our work as doctors work. All workers are exposed to a number of risks, most of them preventable in a collective manner, but in some cases, these measures do not become fully effective it is necessary protective equipment. These teams are intended to be carried or restrained by workers to protect them from risks that may threaten their safety or health in the workplace, but nevertheless they are capable of creating their own effects on the health of workers, derived from its use. For this reason, doctors should monitor the work of health workers, assessing their personal factors that might hinder the use of PPE, inform and train workers on all matters relating to the use of

  6. DETECÇÃO E QUANTIFICAÇÃO DE AFLATOXINAS EM AMOSTRAS DE GRÃOS DE AMENDOIM E DERIVADOS COMERCIALIZADOS NA REGIÃO DE MARÍLIA – SP, 2002-2009

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    Rosângela Aguilar da SILVA

    2013-01-01

    Full Text Available O objetivo do trabalho foi analisar retrospectivamente a ocorrência e a quantidade de aflatoxinas B1 , B2 , G1 e G2 em amostras de grãos de amendoim e derivados coletadas em estabelecimentos comerciais da região de Marília, Estado de São Paulo, no período 2002-2009. Entre as 75 amostras analisadas, 12 (16% continham ní- veis detectáveis de aflatoxinas (≥ 2 μg/Kg pelo método de cromatografia em camada delgada, sendo 4 amostras de amendoim e 8 amostras de paçoca. A aflatoxina do tipo B1 foi detectada em todas estas amostras isoladamente ou em combinação com os tipos B2 , G1 , e G2. Embora a frequência de detecção de aflatoxinas em amendoim e derivados no presente estudo tenha sido relativamente baixa, a continuidade e a otimização do controle de qualidade pela cadeia produtiva e das ações governamentais para avaliação da qualidade destes produtos são essenciais para evitar riscos à saúde do consumidor e prejuízos econômicos.

  7. Análisis de la información que publica la Bolsa Mexicana de Valores: el caso de las empresas listadas en el mercado mexicano de derivados

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    Juan Fernando Guerrero Herrera

    2016-02-01

    Full Text Available Este trabajo presenta un análisis de la información publicada por la Bolsa Mexicana de valores (bmv respecto de las principales empresas listadas, así como de la información publicada por las propias empresas en sus respectivas páginas Web. El estudio incluye a las diez empresas más importantes que cotizan en la bmv. Entre dichas empresas se encuentran las que están listadas en el Mercado Mexicano de derivados (Mexder, es decir, empresas cuyas acciones son activos subyacentes para contratos de instrumentos financieros derivados. La información proporcionada es importante y de gran utilidad para inversionistas, analistas financieros y público en general, ya que contribuye al proceso de fijación de precios de activos financieros que son subyacentes en el Mexder. el presente análisis incluye cuadros con los contratos listados en el Mexder, tanto de futuros como de opciones, así como sus características principales. Asimismo, incluye tablas que muestran los volúmenes que actualmente operan los contratos e instrumentos referidos.

  8. Influencia de la adición en la dieta de los cerdos de extractos derivados de plantas y de la reducción del contenido en sal de los chorizos sobre la vida útil y la prevalencia de Salmonella

    OpenAIRE

    Panea Doblado, Begoña; Albertí Lasalle, Pere; Ripoll García, Guillermo

    2017-01-01

    Aragón es una región con niveles de prevalencia de salmonelosis muy por encima de la media europea (Vico y Mainar-Jaime, 2009). Los extractos derivados de plantas (EDP) poseen propiedades antimicrobianas y actúan sobre el control de la infección por Salmonella spp. en condiciones normales de explotación. Sin embargo, los cambios en la dieta pueden producir cambios en la calidad de la carne y de los productos derivados de ella. Los consumidores consideran que los atributos de ca...

  9. Factors derived from the intrahospitable laboratories that cause stress in infirmary students Factores derivados de los laboratorios intrahospitalarios que provocan estrés en los estudiantes de enfermería Fatores derivados dos laboratórios intra-hospitalares que provocam estresse nos estudantes de enfermagem

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    Liliana Basso Musso

    2008-10-01

    Full Text Available Quantitative, correlation cross-sectional study with descriptive analysis, whose objective was to assess the factors derived from the intra-hospitable laboratories that affect the stress appearance in Infirmary students. The sample consisted of 129 students, which voluntarily acceded to answer questionnaires Evaluative Scale de Hamilton for the Anxiety, validated in 2003, and Questionnaire KEZKAK, both adapted by the investigating group. The obtained data was processed through Microsoft Excel program, appearing: the 100% of the students presented Stress. From the manifestations of Stress, the tensional anxiety and insomnia appear with the biggest percentages. From the Stress producing Factors, in Student's competitions: "having errors on its work and harming the patient", and in the Educational "receiving contradictory orders" are the ones that present greater frequency of intensity, being the Educational factor the preponderant in the appearance of stress. One concludes that is necessary to adapt the educational positions of a guardian in the clinical practices given greater emphasis to the support that will have to be lend to student, with the purpose of diminishing stress an favoring the learning.Estudio transversal, cuantitativo, correlacional con análisis descriptivo, cuyo objetivo fue conocer los factores derivados de los laboratorios intrahospitalarios que inciden en la aparición de estrés en 129 estudiantes de Enfermería, que contestaron los cuestionarios Escala Hamilton y KEZKAK. Los datos fueron procesados con el programa Microsoft Excel, según los resultados: el 100% presenta Estrés. Ansiedad, tensión e insomnio, aparecen con mayor porcentaje. Los Factores Competencias del alumno: "cometer errores en su trabajo y perjudicar al paciente", y en Docente: "recibir ordenes contradictorias" son los que presentan mayor frecuencia, siendo el Docente el predominante en la aparición de estrés. Se concluye que es necesario adecuar las

  10. Teores de isoflavonas e capacidade antioxidante da soja e produtos derivados Isoflavone content and profile and antioxidant activity of soy and soy products

    Directory of Open Access Journals (Sweden)

    Ana Cristina Lopes Barbosa

    2006-12-01

    Full Text Available O objetivo deste estudo foi determinar a capacidade antioxidante, o teor e as formas de isoflavonas presentes nos produtos derivados de soja e compará-los à soja em grão. A capacidade antioxidante foi mensurada por meio do método de cooxidação do beta-caroteno/ácido linoléico e pelo seqüestro de radicais livres (DPPH•. Os resultados mostraram que o conteúdo de isoflavonas nos produtos variou de 95 a 711 mg/100 g (b.s. e o teor de fenólicos totais de 101 a 413 mg equivalentes de catequina/100 g (b.s., sendo que o grão de soja apresentou um conteúdo de 110 e 200 mg/100 g (b.s., respectivamente, para isoflavonas e fenólicos totais. Em relação às formas de isoflavonas a farinha integral e sua respectiva farinha desengordurada e a farinha desengordurada de soja comercial apresentaram predominância de conjugados malonilglicosídeos ebeta-glicosídeos, similar aos grãos de soja. O suplemento à base de gérmen de soja e a farinha desengordurada de soja apresentaram a maior capacidade antioxidante por ambos os métodos (5 µmoles equivalentes de trolox/g e ~ 0,8 µmoles equivalentes de BHT/ g amostra b.s.. Os resultados demonstraram que o conteúdo total e tipo de isoflavonas e o teor de fenólicos dos produtos de soja dependem do processamento e que a capacidade antioxidante desses produtos varia significativamente.The objective of this study was to determine the antioxidant activity and isoflavone content and type of soy seeds and soy products. The antioxidant activity was measured using beta-carotene bleaching and 2.2-diphenyl-1-picryl-hydrazyl (DPPH• free radical methods. The total isoflavone content of soy products varied from 95 to 711 mg/100 g DW (expressed as aglycones and total phenolics content from 101 to 413 mg equivalents of catechin/100 g DW. Soybeans presented 110 and 200 mg/100 g DW of isoflavones and total phenolics, respectively. The beta-glycosides and malonylglycosides were the main forms of the isoflavones

  11. Construcción de un vector de expresión derivado de virus adenoasociados para corregir in vitro el defecto genético de la enfermedad de Morquio A

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    Luis Alejandro Barrera

    2008-09-01

    Full Text Available Introducción. La mucopolisacaridosis IV A (Morquio A es una enfermedad de depósito lisosómico causada por la deficiencia en la actividad de la enzima N-acetil-galactosamina- 6-sulfato-sulfatasa que produce la acumulación intralisosómica de queratán y condroitín-6-sulfato. Hasta el momento, su manejo es paliativo, por lo que las investigaciones se han enfocado en establecer una terapia que pueda aplicarse tempranamente y garantice la expresión estable de la enzima. En este sentido, la terapia génica se presenta como una de las potenciales alternativas terapéuticas para corregir el defecto genético en la mucopolisacaridosis IV A. Objetivo. Construir vectores de expresión derivados de virus adenoasociados para corregir in vitro la deficiencia enzimática en la mucopolisacaridosis IV A. Materiales y métodos. Se produjeron vectores derivados de virus adenoasociados que portaban el gen humano de la enzima N-acetil-galactosamina-6-sulfato-sulfatasa dirigido por el promotor temprano del citomegalovirus humano, empleando un sistema libre de adenovirus. Se transfectaron células HEK293 y fibroblastos humanos Morquio A con los virus recombinantes, y se determinó la actividad enzimática en el lisado celular a las 24 y 48 horas después de la transfección. Resultados. Se obtuvieron virus adenoasociados recombinantes, libres de adenovirus, con títulos hasta de 2,08 x 1010 cápsides/ml. Tanto en células HEK293 como en fibroblastos Morquio A transfectados, se obtuvieron actividades enzimáticas hasta de 3,05 nmoles/mg por hora, 48 horas después de la transfección. Conclusión. Los virus recombinantes producidos expresaron in vitro la enzima GALNS en las células transfectadas. Estos resultados constituyen el paso inicial para el desarrollo de una terapia génica para la enfermedad de Morquio A empleando vectores derivados de virus adenoasociados.

  12. Desenvolvimento de metodologia analítica para a investigação de metilenodioxi derivados em amostras de humor vítreo em vítimas fatais de acidentes de trânsito

    OpenAIRE

    Aline Akemi Ishikawa

    2011-01-01

    Os metilenodioxi derivados estão entre as drogas sintéticas de uso ilícito mais consumidas no ocidente, são substâncias que causam alterações motoras e psíquicas e tem causado grande ameaça a segurança no trânsito, pois estes efeitos afetam o desempenho dos condutores, podendo causar acidentes de trânsito. O humor vítreo é uma matriz biológica disponível apenas nas análises postmortem, e é de grande relevância para toxicologia forense. Constitui uma matriz simples, de fácil coleta e manuseio...

  13. Biotransformation of a cage-like diels-alder adduct and derivatives by Mucor ramosissimus samutsevitsch Biotransformação de um aduto de diels-alder cage-like e derivados por Mucor ramosissimus samutsevitsch

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    Felicia Megumi Ito

    2009-09-01

    Full Text Available The present study aimed to evaluate the ability for biotransformation of the Diels-Alder adduct tricyclo[6.2.1.0(2,7]undeca-4,9-dien-3,6-dione (1 and two synthetic derivatives by the saprobe fungus Mucor ramosissimus Samutsevitsch. Products from oxidation, isomerization and, regioselective and enantioselective reduction were achieved.Neste trabalho avaliou-se a capacidade de biotransformação do aduto de Diels-Alder triciclo[6.2.1.0(2-7]undeca-4,9-dien-3,6-diona (1 e dois derivados sintéticos pelo fungo sapróbio Mucor ramosissimus Samutsevitsch. Produtos de oxidação, isomerização e redução regiosseletiva e enantiosseletiva foram obtidos.

  14. El fallo “Smith” de la Corte Suprema de Justicia de Canadá y el análisis sobre el uso de cannabis y sus derivados para uso medicinal en la actualidad en la Argentina

    OpenAIRE

    Torti Iermini, Marcos Antonio

    2017-01-01

    El presente trabajo tiene como objetivo estudiar la problemática sobre la regulación del uso de la marihuana y sus productos derivados para uso medicinal. Para ello, se presenta el fallo “Smith” de la Corte Suprema de Justicia de Canadá del año 2015. En el mismo, se analizó la cuestión a la luz de las normas que regulan la producción de la marihuana seca como único medio para poder utilizarse en tratamientos médicos, en pacientes que contaran con la autorización pertinente. Esto llevó a que s...

  15. Cafeína reverte prejuízo da memória decorrente da idade com modificações no fator neurotrófico derivado do encéfalo

    OpenAIRE

    Cassia Sallaberry de Souza

    2012-01-01

    Os efeitos benéficos da administração crônica de cafeína sobre a memória têm sido observados em diferentes condições e modelos animais, mas os mecanismos subjacentes aos seus efeitos permanecem desconhecidos. Este estudo buscou investigar se a administração crônica de cafeína pode melhorar o desempenho em uma tarefa de memória em ratos adultos e de meia-idade. Além disso, os efeitos da cafeína sobre o imunoconteúdo do fator neurotrófico derivado encéfalo(BDNF) foi analisado para estabelecer u...

  16. Desenvolvimento de métodos eletroanalíticos para determinação de compostos nitrogenados em combustíveis derivados do petróleo

    OpenAIRE

    Okumura, Leonardo Luiz [UNESP

    2008-01-01

    A presença de traços de compostos organonitrogenados (básicos e neutros), tais como, quinolina, piridina, carbazol e indol em combustíveis derivados do petróleo desempenham um importante papel no tempo de vida dos motores dos veículos. No entanto, essas substâncias podem contaminar o meio ambiente e por isso devem ser controladas, pois a maioria delas são potencialmente carcinogênicas e mutagênicas. Por estas razões, um método confiável e sensível foi desenvolvido para a determinação de compo...

  17. Ação larvicida de derivados arilsulfonílicos da (+- cânfora e da (+- isopinocanfona sobre o carrapato Boophilus microplus Larvicidal action of (+-camphor and (+- isopinocamphone arilsulphonyl derivatives on Boophilus microplus cattle tick

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    A.C.S. Chagas

    2002-10-01

    Full Text Available Testou-se a atividade larvicida de 33 derivados arilsulfonílicos da (+-cânfora e da (+-isopinocanfona no carrapato B. microplus, na busca de princípios ativos menos tóxicos para o seu controle. Os produtos foram obtidos por clorossulfonação da (+-cânfora e da (+-isopinocanfona. Eles foram submetidos à solubilização e testados separadamente e em conjunto contra larvas de carrapato encerradas em envelopes contendo papéis impregnados e acondicionadas em estufa climatizada. A mortalidade média não atingiu 5% em todos os testes realizados, indicando que a clorossulfonação não é a rota de síntese mais adequada para a obtenção de derivados sintéticos com efeito larvicida sobre B. microplus. Os 33 produtos testados sob a forma de triagem biológica não podem ser considerados como potenciais acaricidas.It was investigated the acaricidal activity of (+- camphor and (+- isopinocamphone arilsulphonyl derivatives against Boophilus microplus cattle tick. The products were obtained through the camphor and isopinocamphone clorosulfonation. Thirty-three products were submitted to solubilization and tested alone and together, against tick larvae. Ticks were caught in filter paper envelopes impregnated with products, which were incubated under controlled conditions. The average mortality did not reach 5% in all trials, indicating that clorosulfonation is not an appropiate procedure to obtain derivatives with larvicidal effect against B. microplus. The 33 products tested in the biological screening could not be considered as potential acaricides.

  18. Análisis de la serie de precios del trigo mediante la metodología box-jenkins , y su cointegración con las series de precios de productos derivados

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    Hanns de la Fuente Mella

    2008-04-01

    Full Text Available El siguiente estudio presenta un análisis de series temporales de los precios reales del trigo en Chile, para el período comprendido entre el mes de enero de 1990 y enero de 2007, utilizando la metodología Box-Jenkins. Además, se presenta un análisis de cointegración entre los precios reales del trigo y algunos de sus derivados como el Pan, la Harina y los Tallarines. La muestra fue ajustada con un modelo ARIMA (2,1,1, mostrando algunos inconvenientes en una de las hipótesis que el procedimiento necesita confirmar, lo que fue solucionado aplicando la "Ley de Los Grandes Números", es decir, utilizando el teorema del límite central. Respecto de la cointegración, nuestro supuesto de la existencia de ésta fue validado mediante el test de Phillips-Perron para raíces unitarias, demostrando cuantitativamente la existencia de cointegración entre los precios del trigo y sus derivados en estudio.Además, se valida la hipótesis de estacionalidad de los precios del trigo para los meses de Noviembre, Diciembre y Enero debido a la escasez del producto en dichos períodos.Finalmente, la presencia de cointegración demostrada sirve de incentivo para que futuros investigadores puedan utilizar estos resultados, con el objeto de realizar pronósticos para el precio del trigo y sus derivados, pensando en la existencia de un equilibrio estable entre las variables. The following study presents a serial temporal analysis of the real prices of Wheat in Chili, for the period between, January, 1990 and January 2007 , using the Box- Jenkins methodology. Besides,we present an analysis of cointegration between the real prices of Wheat and sorne of his derivates products like bread, Flour and noodles. We suppose cointegration that was confirmed with the Phillip-Perron test. The sample of data was fitted whit a model ARIMA (2,1,1 showing sorne troubles in one of the hypothes1s that the procedure need to confirm.That was solved by applying de "Big Numbers Law

  19. Electrosíntesis y caracterización de materiales moleculares a partir de derivados n-trifluorometansulfonil-1-azahexa-1,3,5-trienos. // Electrosintesis and characterization of molecular materials starting from having derived.

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    M. E. Sánchez Vergara

    2008-01-01

    Full Text Available Actualmente existe un interés creciente en los Materiales Moleculares, ya que estos pueden presentar diferentescomportamientos eléctricos que van desde aislantes, semiconductores o bien conductores. En el presente estudio fueronsintetizados materiales de este tipo, a partir de derivados N-Trifluorometansulfonil-1-azahexa-1,3,5-trienos yK3[Cr(C2O43]•3H2O debido a que estos compuestos representan un gran interés por sus variadas aplicaciones en camposcomo la química analítica, además los derivados N-Trifluorometansulfonil-1-azahexa-1,3,5-trienos resultan especialmenteatractivos desde el punto de vista estructural ya que en su forma neutra presentan una extensa deslocalización electrónica locual les confiere un comportamiento químico muy particular. En esta comunicación, se forman mediante electrosíntesisconvencional y mediante electrosíntesis en el módulo de electrocristalización del microscopio de fuerza atómica (AFM,algunos materiales moleculares. Una vez obtenidos dichos materiales, se caracterizan por análisis elemental sobresuperficies (SEM-EDS.Palabras claves: Materiales moleculares, anisotropía, electrocristalización._____________________________________________________________________________Abstract.Recently, molecular materials have been developed because of their electrical properties which give conductor,semiconductor, or superconductor behavior. In this work, the synthesis of new materials formed from Ntrifluoromethanesulfonyl-1-azahexa-1, 3, 5-triene species and K3[Cr(C2O43]•3H2O is reported. NTrifluoromethanesulfonyl-1-azahexa-1,3,5-trienes compounds, which are highly functionalised pentametines, have alsobeen studied due to its interesting physical and chemical properties. These compounds are especially interesting from astructural point of view for some reasons; in a neutral form, they show an extensive electronic delocalisation, which confersthem a very particular chemical behaviour. This study is focused on

  20. Estudio del grado de pureza de la nitrofurazona obtenida a partir de un derivado de la industria cañera cubana Study of the purity degree of Nitrofurazone obtained from a Cuban sugar cane industry byproduct

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    Adolfo L Brown Gómez

    2006-04-01

    Full Text Available Se estudió el grado de pureza a diferentes lotes de nitrofurazona sintetizados en el Instituto Cubano de Investigaciones de Derivados de la Caña de Azúcar (ICIDCA mediante la combinación de 3 técnicas analíticas: la cromatografía de placa delgada, la cromatografía líquida de alta resolución y la calorimetría diferencial de barrido. Se obtuvieron resultados satisfactorios que permiten evaluar la calidad de los productos y compararlos con productos competitivos a escala comercial con purezas entre el 98 y 100 %The purity degree of different Nitrofurazone batches synthetized in ICIDCA was studied using combination of three analytical techniques: the Thin Layer Chromatography (TLC, High Performance Liquid Chromatography (HPLC and Differential Scanning Calorimetry (DSC. Positive results were obtained that permit to evaluate quality of products and to compare them with competitive products at a market scale with 98 and 100 % purity degree

  1. Estudo das propriedades térmicas de filmes poliméricos compostos de Speek, derivados do benzoimidazol e ácido fosfotúngstico Thermal properties of Speek-based polymeric films containing benzimidazole derivatives and fosfotungstic acid

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    Fabrício Celso

    2008-06-01

    Full Text Available Filmes poliméricos foram desenvolvidos a partir de poli (éter éter cetona sulfonado (SPEEK, derivados do benzoimidazol e ácido fosfotúngstico (HPW. Neste trabalho foi realizado um estudo utilizando a análise termogravimétrica com o objetivo de avaliar a estabilidade térmica e determinar as condições de temperatura a que podem ser submetidos os filmes produzidos, tendo em vista a aplicação de tais filmes como membranas em células a combustível. Os resultados obtidos mostram que a estabilidade térmica é afetada pela composição dos filmes. A maioria dos filmes se mostrou estável até 140 °C.Polymeric films were developed from sulfonated poly(ether ether ketone (SPEEK, benzimidazole derivatives and phosphotungstic acid (HPW. In this study, thermogravimetric analysis was performed with the aim of evaluating the temperature conditions to which polymeric films can be submitted. The results showed that thermal stability depended on film composition and the majority of the tested films showed to be stable up to 140 °C.

  2. Variações diárias nas excreções de creatinina e derivados de purinas em novilhas Daily variation in the urinary excretion of creatinine and purine derivatives in heifers

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    Thalita Lázaro Leal

    2007-08-01

    Full Text Available Objetivou-se avaliar as variações nas excreções diárias de creatinina e de uréia na urina utilizando coletas durante seis dias consecutivos em novilhas de origem leiteira; avaliou-se também o efeito da duração do período de coleta sobre a estimativa da produção microbiana obtida a partir dos derivados de purinas na urina. Utilizaram-se onze novilhas de grau de sangue predominantemente Holandês, com 287 ± 49 kg, considerando o grupo de animais como amostra aleatória simples da população. Para comparação entre dias de coletas, empregou-se análise de variância como ferramenta para isolamento do erro puro, adotando-se modelo constituído pelo efeito aleatório de animal e pelo efeito fixo de dia de avaliação. O volumoso foi constituído de silagem de milho fornecida à vontade. Diariamente, foram fornecidos 2,0 kg de concentrado por animal. O período experimental teve duração de seis dias, pois os animais já estavam adaptados à dieta. As coletas de urina foram realizadas utilizando-se sondas de Folley nº 22 ou 26, sendo determinado o volume urinário diário. As excreções urinárias de creatinina, uréia, alantoína, ácido úrico e derivados de purinas totais não foram afetadas pelos dias de coleta de urina. Do mesmo modo, a quantidade estimada de proteína microbiana não diferiu entre os dias de coleta de urina. O valor médio para a excreção de creatinina foi de 30,5 mg/kgPV, 124,84 mg/kg0,75 ou 1,1 mmol/kg0,75. A ausência de efeito de número de dias sobre a excreção de creatinina tem grande aplicação prática, pois, além de reduzir o trabalho com tempos longos de coleta, permite a redução dos custos da pesquisa, podendo ser recomendadas coletas de urina com duração de 24 horas.The objective of this trial was to investigate the daily variation in the urinary excretions of creatinine and nitrogen compounds in dairy heifers. It was also of particular interest to determine whether or not estimation of

  3. Revisão: Polifenóis em cacau e derivados: teores, fatores de variação e efeitos na saúde Review: Polyphenols in cocoa and derivatives: factors of variation and health effects

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    Priscilla Efraim

    2011-09-01

    Full Text Available O número de estudos sobre os polifenóis presentes no cacau tem aumentado consideravelmente nos últimos anos, principalmente relacionando-os aos benefícios à saúde humana. Mais recentemente, alguns trabalhos têm procurado prever o teor de polifenóis em produtos derivados de cacau com base no teor de sólidos desengordurados de cacau (SDC e como o processamento afeta os polifenóis do cacau. As compilações da literatura, em geral, aprofundam os mecanismos dos efeitos benéficos dos compostos fenólicos do cacau no organismo humano. Esta revisão fornece um panorama das principais pesquisas relacionadas aos altos teores de polifenóis presentes no cacau e produtos derivados, bem como aos seus benefícios à saúde. Além disso, busca apresentar aspectos tecnológicos que influenciam o perfil dos compostos fenólicos durante as etapas de processamento. Pelas pesquisas científicas, a destruição dos compostos fenólicos naturalmente presentes nas sementes se dá principalmente nas etapas realizadas para o desenvolvimento do sabor de chocolate, as quais favorecem a diminuição da adstringência e do amargor. Os polifenóis, responsáveis pela capacidade antioxidante do cacau, são drasticamente reduzidos durante a fermentação das sementes e a alcalinização dos nibs e liquors, etapas que envolvem a ocorrência de complexas reações bioquímicas ou uma significativa variação do pH. A produção de chocolate ao leite ou amargo, excluindo o chocolate branco, apresenta um enorme potencial para inovação tecnológica, visto a necessidade da manutenção destes compostos importantes para a saúde, sem prejuízo do sabor agradável, atributo esperado e de grande importância em produtos como o chocolate.The number of studies on cocoa polyphenols has increased significantly in recent years, mainly due to their benefits on human health. Recently, some researchers have studied how to predict the polyphenolic content of cocoa products based

  4. Revisión: Uso de Ingredientes no Cárnicos como Reemplazantes de Grasa en Derivados Cárnicos Use of non-Meat Ingredients as Fat Replacers in Meat Derivatives: A Review

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    Waldir Augusto Pacheco Pérez

    2011-12-01

    Full Text Available Se realizó una revisión de literatura en la que se describen las diferentes alternativas en materia de ingredientes y aditivos no cárnicos que se han venido evaluando como reemplazantes de grasa en el desarrollo de derivados cárnicos bajos en grasa. Estas posibilidades apuntan a buscar respuestas ante las necesidades que se han generado dentro del sector cárnico, en cuanto a la formulación y elaboración de derivados cárnicos saludables, que cumplan con los requerimientos y actuales hábitos alimenticios asociados a las nuevas tendencias de la industria alimentaria. En esta revisión se mencionan estudios realizados acerca del uso de ciertos ingredientes a base de carbohidratos, proteínas y lípidos; al igual que algunas anotaciones sobre los resultados y las conclusiones establecidas por los respectivos autores. La revisión realizada arrojo que dentro de los diferentes ingredientes evaluados, los reemplazantes de grasa a base de carbohidratos, específicamente los hidrocoloides, mostraron las mayores aplicaciones ya que en muchas investigaciones se lograron mantener algunas características funcionales y organolépticas en el producto final similares a las de un producto elaborado con grasa animal. De otro lado, los reemplazantes de grasa a base de lípidos modificados químicamente, mostraron ser una alternativa promisoria; ya que la modificación de sus propiedades físicas y químicas, ayuda a minimizar ciertos aspectos desfavorables que pueden aparecer en el producto final durante el procesamiento, como la producción de ácidos grasos trans.A literature review, where the different alternatives in terms of non-meat ingredients and additives that have been evaluated as fat replacers in the development of low fat meat derivatives, was carried out. These possibilities aim at looking for response to the necessity that have been generated within the meat sector, in the formulation and manufacturing of healthy meat derivatives, that

  5. Silício alterando compostos derivados da pirólise de bainhas foliares de plantas de arroz infectadas por Rhizoctonia solani Silicon altering compounds derived from the pyrolyses of leaf sheaths of rice plants infected with Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    Daniel Augusto Schurt

    2013-01-01

    Full Text Available Este trabalho teve como objetivo elucidar, por meio da pirólise analítica acoplada à cromatografia gasosa e espectrometria de massa, alterações na composição química da lignina nas bainhas de plantas de arroz das cultivares BR-Irga 409 e Labelle supridas ou não com silício (Si e infectadas por Rhizoctonia solani. A concentração de Si nas bainhas das plantas supridas com esse elemento foi significativamente maior (2,7 dag kg-1 em comparação com as plantas não supridas (0,45 dag kg-1. Na presença de Si, a área abaixo da curva do progresso da queima das bainhas foi significativamente reduzida em 19 e 25%, respectivamente, para as plantas das cultivares BR-Irga-409 e Labelle em relação à ausência desse elemento na solução nutritiva. Com base nos espectros de massas obtidos, foram identificados 33 compostos, dos quais 10 foram produtos da degradação de carboidratos e 23 derivados da lignina. Dentre os derivados da lignina, oito compostos eram do tipo p-hidroxifenila, 11 compostos do tipo guaiacila e quatro compostos do tipo siringila. Nas bainhas das plantas das duas cultivares de arroz, supridas ou não com Si, a concentração de lignina (p-hidroxifenila, siringila (S e guaiacila (G foi de, aproximadamente, 15%. Houve aumento na relação S/G apenas nas bainhas das plantas da cultivar BR-Irga 409 supridas com Si e infectadas por R. solani. A maior concentração de Si nas bainhas das plantas de arroz das duas cultivares, que por sua vez resultou em aumento na relação S/G, contribuiu para reduzir os sintomas da queima das bainhas.This study elucidated, through analytical pyrolysis coupled to gas chromatography and mass spectrometry, changes in the chemical composition of lignin on leaf sheaths of rice plants of cultivars BR-Irga 409 and Labelle supplied or non-supplied with silicon (Si and infected with Rhizoctonia solani. The Si concentration on leaf sheaths of plants supplied with this element was significatively higher

  6. Nanocompósitos poliméricos de polietileno de alta densidade contendo hidróxidos duplos lamelares intercalados com ânions derivados de corantes azo

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    Ademir Zimmermann

    2014-06-01

    Full Text Available O presente trabalho descreve a síntese e caracterização de hidróxidos duplos lamelares (HDL de Zn/Al na razão molar 2:1, os quais foram intercalados com íons cloreto hidratados e ânions derivados dos corantes azo alaranjado de metila (AM e alaranjado II (AII. Após caracterização, os materiais foram utilizados como cargas em polietileno de alta densidade (PEAD e nanocompósitos foram preparados por extrusão e injeção, seguindo a norma ASTM D638-10. Os teores de cargas variaram de 0,1 até 2% (incluindo-se os sais de sódio dos corantes e os nanocompósitos homogêneos foram avaliados em relação as suas propriedades estruturais, térmicas e mecânicas. De modo geral, após a adição das cargas existe somente uma pequena influência na temperatura de fusão e cristalização do PEAD. Para os HDLs contendo o pigmento intercalado com o ânion do corante AM e sais de sódio de ambos os corantes, as propriedades mecânicas apresentaram leve aumento do módulo e tensão de ruptura e diminuição do alongamento em relação ao polímero puro e um comportamento inverso foi observado para o ânion AII, além do HDL contendo ânions cloreto hidratados.

  7. Avaliação da carga de trabalho dos operadores de uma empresa distribuidora de derivados de petróleo Evaluation of an oil distributor company operator's workload

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    Lucimara Ballardin

    2009-01-01

    Full Text Available Este artigo mostra o método adotado e os resultados obtidos em estudo realizado com operadores de uma distribuidora de derivados de petróleo da região Sul do Brasil. O objetivo era avaliar a carga de trabalho e os fatores que interferem nessa carga, do ponto de vista dos operadores. A metodologia aplicada incluiu entrevistas e dois questionários, um adaptado do NASA-TLX e um para levantamento dos fatores que interferem na carga de trabalho. Os resultados indicaram que a maioria dos operadores percebe que a carga de trabalho é alta. Entre os componentes da carga de trabalho, o desempenho é a que tem peso maior, enquanto os problemas relacionados a equipamentos e sistemas informatizados são os que mais influenciam nessa carga. Tendo em vista os resultados obtidos, é necessário aperfeiçoar os subsistemas, técnico e organizacional, da empresa para gerar melhorias na performance, saúde e satisfação dos operadores.The aim of this study was to evaluate workloads as perceived by the operators of an oil distribution company in Southern Brazil. Workload levels were measured by a questionnaire adapted from the NASA-TLX, and the factors that impact on the workload were identified by interviews and questionnaire. The results showed that the workload level is high, mainly due to technical constraints (such as equipment and computational problems. Performance is the component which most influences workload. According to the results, it is necessary to improve the technical and organizational subsystems of the oil distribution company in order to improve human performance as well as the health and safety of the operators.

  8. Avaliação do potencial de aproveitamento energético dos resíduos de madeira e derivados gerados em fábricas do polo moveleiro de Ubá - MG

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    Rogério Machado Pinto Farage

    2013-03-01

    Full Text Available http://dx.doi.org/10.5902/198050988454O presente estudo avaliou o potencial de reaproveitamento energético dos resíduos de madeira e seus derivados gerados no Polo Moveleiro de Ubá, MG. Painéis reconstituídos de MDF (medium density fiberboard, aglomerado e compensado foram caracterizados e classificados, identificando assim as oportunidades e possíveis limitações quanto à sua utilização. Por meio de diagnóstico realizado em 11 fábricas de móveis, verificou-se que os resíduos de madeira compreendem mais de 90 % do total dos resíduos sólidos gerados. Além da grande quantidade gerada, não foi identificada nenhuma ação integrada entre as fábricas do Polo para o adequado gerenciamento dos resíduos, negligenciando seus riscos ambientais e sanitários, bem como seu potencial energético. Contudo, os teores de umidade e poder calorífico dos resíduos demonstraram potencial para o seu reaproveitamento energético através da produção de briquetes. Os gases gerados em ensaios de combustão dos resíduos não apresentaram substâncias ou compostos tóxicos acima dos limites preconizados pelas normas ambientais, verificando, neste aspecto, um bom desempenho ambiental para o aproveitamento destes resíduos conforme proposto pelo presente estudo. Entretanto, as cinzas dos resíduos de aglomerado BP (baixa pressão e FF (finish foil apresentaram elevadas concentrações de cromo, enquadrando-se como Classe I (perigosos, segundo a ABNT/NBR 10004/2004.

  9. Desenvolvimento de farinhas mistas extrusadas à base de farinha de milho, derivados de levedura e caseína Development of extruded mixed flours based on corn flour, yeast derivates and casein

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    Izabela Dutra Alvim

    2002-08-01

    Full Text Available O presente trabalho teve como principal objetivo o desenvolvimento de farinhas mistas extrusadas à base de farinha de milho, derivados de levedura (autolisado ou extrato e caseína como ingredientes. Utilizou-se a extrusão como processo, sem a pretensão de otimizá-lo, mas buscando as condições que permitissem uma boa operacionalidade do extrusor e produtos extrusados com boas propriedades funcionais, boa aceitação e elevado valor nutritivo. As condições adotadas para o processo foram: alimentação do extrusor, 85g/min; velocidade do parafuso, 150rpm; relação de compressão do parafuso, 1:3; umidade inicial da amostra, 25%; e temperatura de extrusão 170ºC. A melhoria das características nutritivas foi assegurada pela elevação dos teores de proteína e de fibra e diminuição do teor de carboidrato, em relação à farinha sem adição. A extrusão promoveu um adequado grau de expansão radial (GER, aumentou os índices de absorção e de solubilidade em água e diminuiu sensivelmente a viscosidade, em relação à farinha de milho crua.The main objective of the present work was the development of extruded mixed flours based on corn flour, yeast derivatives (autolysate or extract, and casein, as ingredients. The extrusion process was used as unit operation with the purpose of achieving good operation condition for the equipment, and extruded products of good functional properties and acceptability and high nutritive properties. The adopted operational conditions for the process were: feeding rate of the extruder; 85g/min; screw velocity, 150rpm; screw compression ratio, 1:3; sample initial moisture, 25%; and extrusion temperature, 170ºC. Improvement of the nutritional characteristics was assured by the elevation of protein and total fiber content and a decrease in carbohydrate, as related to the corn flour without enrichment. The extrusion promoted an adequate degree of radial expansion (DRE, increased the indexes of water

  10. CARACTERIZACIÓN CUANTITATIVA DE PRODUCTOS INTERMEDIOS Y RESIDUOS DERIVADOS DE ALIMENTOS DEL ALGARROBO (PROSOPIS FLEXUOSA Y P. CHILENSIS, FABACEAE: APROXIMACIÓN EXPERIMENTAL APLICADA A RESTOS ARQUEOBOTÁNICOS DESECADOS

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    Aylen Capparelli

    2008-01-01

    Full Text Available Mediante una aproximación experimental se caracterizan los atributos macromorfológicos cuantitativos de productos intermedios y residuales derivados de Prosopis chilensis y P. flexuosa (Algarrobo blanco y Algarrobo negro respectivamente que potencialmente podrían llegar a formar parte del registro arqueobotánico. Se provee descripción morfoanatómica de la vaina y la semilla de las especies tratadas. Se elaboró harina no refinada y refinada, añapa, aloja y arrope, siguiendo técnicas tradicionalmente utilizadas en el Valle de Hualfín, Catamarca, Argentina, las cuales fueron registradas por la autora en trabajos previos. Se concluye que el análisis cuantitativo de restos macrobotánicos de Prosopis, en conjunto con el cualitativo, permite la identificación de diferentes etapas de procesamiento del Algarrobo. Para ello resulta esencial la distinción entre las dos especies. La proporción de diferentes categorías de semillas y endocarpos es útil para distinguir la harina refinada de la no refinada. Esta última podría indicar la manufactura de patay, ulpo o aloja. Los residuos de la añapa y aloja se caracterizan por presentar semillas con testa plegada, enrollada o levantada, o carecer de ella, y sus cantidades se encuentran disminuidas o aumentadas con respecto a la cantidad inicial de harina utilizada dependiendo de si las semillas que se recuperan son enteras o fragmentadas. Los residuos del arrope se identifican por poseer grandes piezas de epicarpo y porque todos los endocarpos correspondientes a la cantidad de artejos utilizados inicialmente en su preparación se encuentran presentes. Dichos endocarpos se encuentran cerrados, y excepto en el caso de los residuos de arrope, se considera que la mayoría de las asociaciones arqueológicas de restos de Prosopis representa una proporción muy baja del volumen de materia que le dio origen en su contexto dinámico del pasado.

  11. Determinação da fibra alimentar insolúvel, solúvel e total de produtos derivados do milho Determination of insoluble, soluble, and total dietary fiber of corn products

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    Maria da Graça Kolinski Callegaro

    2005-06-01

    Full Text Available A cultura do milho é de grande importância na agricultura brasileira, com ampla distribuição do norte ao sul do país. O milho pode ser uma fonte significativa de fibra, dependendo da forma como é utilizado na alimentação. O objetivo deste trabalho foi avaliar os teores de fibra alimentar insolúvel (FAI, solúvel (FAS e total (FAT de produtos derivados do milho. Determinou-se também os teores de umidade, resíduo mineral fixo, extrato etéreo e proteína bruta das amostras analisadas. Trabalhou-se com amostras de canjica, pipoca, farinha fina, farinha média e farinha pré-cozida. O método utilizado na determinação de fibra foi o de Prosky et al. Entre os produtos analisados observou-se que a pipoca apresentou o maior teor de FAT (média de 12,15% e a canjica o menor (média de 2,39 %. Em relação às farinhas, a fina e a média apresentaram teores de fibra semelhantes, enquanto as amostras de farinha pré-cozida apresentaram um teor um pouco mais baixo. Em todos os produtos analisados, a FAI correspondeu a mais de 90% da fibra total. Quanto aos demais constituintes avaliados, encontrou-se, neste trabalho, valores de acordo com os já disponíveis na literatura.Corn crop is of great importance to Brazilian agriculture, ranging from the north to the south of the country. Corn can be an important source of fiber, depending on the way it is used as food. The objective of this work was to evaluate the content of insoluble (IDF, soluble (SDF, and total (TDF dietary fiber of corn-derived products. The content of moisture, ash, lipids, and crude protein were also determined in the samples. We have worked with "canjica", popcorn, and meal (finely ground, medium ground, and pre-cooked. The PROSKY'S enzymic-gravimetric method was used to determine dietary fiber. Among the products analyzed, we have observed that the popcorn showed the greatest content of TDF (12.15%, and the "canjica" showed the smallest one (2.39%. Thin and medium corn meals

  12. The value of colonoscopy to assess rectal bleeding in patients referred from Primary Care Units Utilidad de la colonoscopia en pacientes derivados desde Atención Primaria por rectorragia

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    A. Sánchez

    2005-12-01

    Full Text Available Objectives: rectal bleeding is very common in the general population. It is produced mainly because of benign disease originating in the anus and the rectum. Our aim was to evaluate the need for colonoscopy in patients presenting with rectal bleeding. Patients and methods: patients referred from Primary Care Units and complaining of rectal bleeding were included prospectively in a three-month study. All patients underwent a careful medical history along with physical examination, laboratory tests, and colonoscopy. Results: 126 patients with a mean age of 49.2 years (range: 19-80 were studied. Rectal digital examination was abnormal in 75 cases (59.5%. Severe disease was encountered in 22 patients (neoplasm, angiodysplasia, and inflammatory bowel disease; 10 patients had polyps, 6 had colorectal cancer, and 6 had inflammatory bowel disease. Out of 63 patients younger than 50 years, 5 had severe disease, all of them in the form of inflammatory bowel disease. Conclusions: a neoplasm of the rectum and colon in patients younger than 50 years is a rare event. A colonoscopy must be performed in this group of patients to rule out inflammatory bowel disease.Objetivos: la rectorragia es frecuente en la población general. En la mayoría de las ocasiones está producida por patología anorrectal benigna. Nuestro objetivo era determinar la necesidad de realizar pruebas endoscópicas en pacientes con rectorragia. Pacientes y métodos: se incluyeron de forma prospectiva durante tres meses todos los pacientes que eran derivados desde la Atención Primaria por rectorragia. En todos los pacientes se realizó historia clínica y exploración física que incluía tacto rectal, analítica básica y una colonoscopia. Resultados: se incluyeron 126 pacientes con una edad media de 49,2 años (19-80. El tacto rectal fue anormal en 75 (59,5%. En 22 pacientes se encontró patología severa o positiva (lesiones neoplásicas, angiodisplasias y enfermedad inflamatoria

  13. Indução de fitoalexinas em cotilédones de soja em resposta a derivados de folhas de pitangueira Induction of phytoalexins in cotyledons of soybean in response to the derivatives of leaf surinan cherry

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    Sergio Miguel Mazaro

    2008-10-01

    Full Text Available A demanda mundial por alimentos isentos de agrotóxicos tem impulsionado a pesquisa para a busca de métodos alternativos ao controle de patógenos em plantas. A ativação dos mecanismos de defesa com o uso de indutores vem demonstrando ser uma alternativa viável e promissora. O uso de extratos de plantas medicinais tem demonstrado capacidade para induzir a produção de fitoalexinas, como um mecanismo de defesa em plantas tratadas. O objetivo deste trabalho foi verificar o potencial da planta Eugenia uniflora L. (pitangueira em induzir fitoalexinas em cotilédones de soja (Glycine max. Os derivados de extrato alcoólico, infusão, maceração e decocção, obtidos de folhas de pitangueira, foram usados nas concentrações de 0,1; 1; 10 e 40%, além de óleo essencial. Água foi utilizada como controle e quitosana (1% como indutor de referência. Os preparados de pitangueira apresentaram capacidade de indução das fitoalexinas gliceolinas em cotilédones de soja, respondendo ao aumento das concentrações dos preparados. O óleo essencial apresentou destacável efeito na indução de fitoalexinas, sendo superior aos demais preparados. Quitosana induziu fitoalexinas em cotilédones de soja e pode ser utilizado em estudos similares como um indutor de referência.The worldwide demand for food without pesticides has stimulated the research on alternative methods to control pathogens in plants. The activation of defense mechanisms by inductors seems a viable and promising alternative. The use of medicinal plants extracts has demonstrated capacity to induce the production of phytoalexins, as a mechanism of defense in treated plants. The objective of this research was to verify the potential of Eugenia uniflora L. (surinan cherry to induce phytoalexins in cotyledons of soybean (Glycine max. The derivatives alcoholic extract, infusion, maceration and decoction, obtained of surinan cherry were used in the concentrations of 0.1; 1; 10 and 40%, beyond

  14. Variações diárias nas excreções de creatinina e derivados de purinas em novilhos Daily variation in the excretion of creatinine and purine derivatives in steers

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    Thalita Lázaro Leal

    2007-08-01

    Full Text Available Objetivou-se estimar as variações nas excreções diárias de creatinina, uréia e derivados de purinas (DP na urina utilizando coletas durante seis dias consecutivos e avaliar as concentrações de nitrogênio uréico no plasma (NUP em novilhos. Utilizaram-se quatro animais, machos castrados, de grau de sangue predominantemente Holandês, peso médio de 445 kg, distribuídos em quadrado latino 4 x 4, com os tratamentos definidos em esquema fatorial 2 x 2 (dois níveis de uréia em substituição ao farelo de soja: 0 e 100%; e dois níveis de oferta de concentrado: 0,75 e 1,25% do PV e a comparação entre dias de avaliação, em esquema de parcelas subdivididas. O volumoso, constituído de silagem de capim-elefante (80% e silagem de sorgo (20%, foi fornecido à vontade. A síntese de compostos nitrogenados microbianos, estimada a partir da excreção de DP, foi maior quando houve maior oferta de concentrado e menor quando a proteína do farelo de soja foi substituída pela uréia. Não houve efeito da interação níveis de concentrado ´ níveis de uréia nem efeito de níveis de uréia sobre a concentração de NUP e a excreção de N-uréico na urina. As excreções urinárias de uréia, alantoína, ácido úrico e a quantidade estimada de proteína microbiana não foram afetadas pelos dias de coleta de urina. Não houve diferença na excreção de creatinina entre os dias de coleta, sendo obtido valor médio de 25,47 mg/kgPV, 117,92 mg/kg0,75 ou 1,04 mmol/kg0,75. A ausência de efeito de número de dias sobre a excreção de creatinina tem grande aplicação prática. Na estimativa da excreção de creatinina e de derivados de purinas, recomendam-se coletas de urina com duração de 24 horas.The objective of this trial was to investigate the daily variation in the urinary excretions of creatinine, urea and purine derivatives (PD as well as the plasma concentration of urea-N (PUN in steers. Four castrated Holstein steers averaging 445 kg

  15. Validación de la prueba de identificación de trastornos derivados del consumo de alcohol (AUDIT en pacientes Mexicanos con esquizofrenia Validation of the alcohol use disorders identification test (AUDIT in Mexican patients with schizophrenia

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    Valerio Villamil Salcedo

    2009-10-01

    Full Text Available OBJETIVOS: Validar la Prueba de Identificación de Trastornos Derivados del Consumo de Alcohol (AUDIT, por su sigla en inglés en pacientes con esquizofrenia. MÉTODOS: Se aplicó la Cédula Diagnóstica Internacional Compuesta (CIDI, por su sigla en inglés versión 1.0 y el AUDIT a 80 sujetos con esquizofrenia, de ambos sexos y mayores de 16 años, de la consulta externa del Instituto Nacional de Psiquiatría de la ciudad de México. RESULTADOS: De los 80 pacientes esquizofrénicos, 57 eran hombres y 23 mujeres con un promedio de edad de 30,5 y 34,3 años, respectivamente; la edad de inicio de la esquizofrenia fue de 22 años para los hombres y 26 años para las mujeres; 35 sujetos (43,7% consumían alcohol al momento del estudio. La escala AUDIT mostró alta consistencia interna, con un alfa de Cronbach de 0,812; el punto de corte de la escala completa del AUDIT para esta población fue de 4 puntos o más; se construyeron los puntos de corte de la "prueba rápida" y de los "Problemas psicosociales y probable dependencia al alcohol" del AUDIT utilizando como estándar de comparación el CIDI (DSM-III-R y CIE-10. CONCLUSIONES: La validación del AUDIT mostró que es un instrumento de tamizaje muy útil y sensible para identificar a pacientes con esquizofrenia en riesgo de abuso o dependencia de alcohol, por lo que se recomienda su uso en estudios clínicos y epidemiológicos en Latinoamérica.OBJECTIVES: To validate the Alcohol Use Disorders Identification Test (AUDIT in schizophrenic patients. METHODS: The Composite International Diagnostic Interview (CIDI v. 1 and the AUDIT were administered to 80 subjects with schizophrenia, of both sexes, more than 16 years of age, from the outpatient services at the National Institute of Psychiatry in Mexico City. RESULTS: Of the 80 schizophrenic patients, 57 were men and 23 women, with a mean age of 30.5 years and 34.3 years, respectively; the age at schizophrenia onset was 22 years for men, and 26 years

  16. Consumo, digestibilidade e excreção de uréia e derivados de purinas em novilhas de diferentes pesos Intake, digestibility and urinary excretion of urea and purine derivatives in heifers with different body weights

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    Mario Luiz Chizzotti

    2006-08-01

    Full Text Available Objetivou-se avaliar a influência do peso vivo de novilhas sobre o consumo e a digestibilidade da MS, MO, EE, PB, fibra em detergente neutro corrigida para cinzas e proteína (FDNcp e carboidratos não-fibrosos corrigidos (CNFcp, os consumos de NDT e de proteína degradada no rúmen (PDR, a produção de proteína microbiana e a excreção de compostos nitrogenados na urina e comparar as metodologias de coleta spot e de coleta total de urina. Foram utilizadas 22 novilhas com cinco diferentes pesos (523, 453, 315, 235 e 118 kg, distribuídas em delineamento inteiramente casualizado, com cinco tratamentos (P523, P453, P315, P235 e P118. A alimentaç��o foi constituída de silagem de milho e concentrado, fornecido na proporção de 1,5 kg/dia (tratamentos P523, P453, P315 e P235 ou 2 kg/dia (tratamento P118. Os consumos dos nutrientes em kg/dia e em %PV aumentaram e diminuíram linearmente, respectivamente, com o aumento do peso dos animais. As digestibilidades da MS, MO e o teor de NDT não diferiram entre os tratamentos, enquanto as de PB e FDNcp foram distintas entre os tratamentos, sendo maior e menor, respectivamente, no tratamento P118. A excreção de uréia na urina (em mg/kgPV foi maior no tratamento P118, variando com o peso vivo e com o consumo de PB e PDR. A produção microbiana, estimada pela excreção urinária de derivados de purinas, não diferiu entre as metodologias de coleta spot e coleta total de urina, sendo menor no tratamento P118. A coleta de urina spot pode ser utilizada para estimativa da excreção de compostos nitrogenados na urina, independentemente do peso vivo. A quantidade de nutrientes ingeridos diariamente aumenta com o peso vivo, entretanto, o consumo desses nutrientes, expresso em %PV, diminui à medida que o peso vivo aumenta.The objective of this trial was to evaluate the effect of body weight (BW of heifers on intake, apparent digestibility of nutrients, microbial protein synthesis, ruminal metabolism

  17. SUBACUTE AND MULTIGENERATIONAL TOXICITY EVALUATION OF CASTOR OIL POLYMER INGESTION IN RATS AVALIAÇÃO DA TOXICIDADE SUBAGUDA E MULTIGERACIONAL DA INGESTÃO DE DERIVADO DO POLÍMERO DE MAMONA EM RATOS

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    Gilberto Chierice

    2009-04-01

    Full Text Available Castor oil polymer is a biomaterial that can be used to fill bone defects. Biomaterials should present some characteristics such as: biocompatibility, inert, absence of toxin radical and vapour discharge and permit the organism to recognize them as a part of their structure. The aim of this study was to investigate changes in water ingestion, feed intake, weight gain and toxic effects in rats (Rattus norvegicus after ingestion of 0, 10, 25 and 50% of castor oil polymer (COP, Ricinus communis. In groups that received 10 and 25% of COP the weight gain was smaller than the control group. Feed intake in control group was greater than in groups 10 and 50% COP. The intake of castor oil polymer reduced feed intake and water ingest probably because of the palatability of the product. In the second part of this study (multigenerational there were no toxic effects in the offspring, as external birth defects or alterations incompatible with life, in spite of the fact that lower weight were observed in males and females of the second generation.

    KEY WORDS: Biomaterials, bone defects, polymer, Ricinus communis. Os biomateriais são polímeros artificiais desenvolvidos para substituir tecidos orgânicos danificados e preencherem falhas ósseas. Eles devem apresentar características como a biocompatibilidade, serem inertes, não liberarem vapores e radicais tóxicos e permitirem ao organismo reconhecê-los como parte de sua estrutura. Procurou-se determinar a ingestão de água, o consumo de ração, ganho de peso e possível efeito tóxico decorrentes da ingestão de três doses (10%, 25% e 50% do derivado do polímero de mamona (PM, Ricinus communis, adicionado à água de bebida, em ratos (Rattus norvegicus. Nos grupos que receberam 10% e 25% do PM, o ganho de peso foi menor (P?0,05, quando comparado ao grupo-controle. O consumo de ração nos grupos que receberam 10% e 50% de PM foi menor em relação ao grupo-controle. A ingestão do pol

  18. Gênese de solos derivados de rochas ultramáficas serpentinizadas no sudoeste de Minas Gerais Genesis of soils formed from ultramafic serpentinized rocks in southwestern Minas Gerais (Brazil

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    Pablo Vidal-Torrado

    2006-06-01

    Full Text Available Os solos derivados de rochas serpentinizadas ou serpentinitos constituem um grupo especial de solos em toda superfície terrestre. De caráter ultramáfico, ou seja, rochas com mais de 70 % de minerais máficos (ferromagnesianos, os serpentinitos apresentam uma mineralogia pobre em sílica e escassa em Al, sendo, no entanto, muito enriquecida em Mg. São poucos os estudos sobre a morfologia, mineralogia, gênese e classificação dos solos desenvolvidos de tais rochas. Em ambiente tropical úmido no sudoeste de Minas Gerais, na zona do greenstone belt do Morro de Ferro, em superfícies geomórficas jovens, três perfis de solos representativos dessa paisagem sobre rochas serpentinizadas foram caracterizados por meio de descrições macro e micromorfológicas, análises granulométricas, químicas e por mineralogia de raios X das frações argila e silte. Complementarmente, para acompanhamento da alteração geoquímica dos horizontes do solo, foram feitas microanálises das seções delgadas por EDRX. Os solos foram classificados como Chernossolo Háplico Férrico típico, Cambissolo Háplico eutroférrico léptico e Neossolo Regolítico eutrófico típico e, embora situados num clima que favorece o rápido intemperismo, do ponto de vista morfológico e mineralógico, mostraram-se similares aos solos derivados de rochas serpentinizadas das regiões subtropicais e temperada. No processo de formação de solo, a evolução da trama segue a seguinte seqüência: alteração da rocha ® trama frâgmica ® trama porfírica com cavidades ® trama porfírica aberta por coalescência de cavidades. O processo de argiluviação é evidente e se dá em dois estádios distintos: argiluviação primária, que ocorre nas fendas e cavidades que se formam por alteração de rocha, e argiluviação secundária, verificada na porosidade mais aberta e evoluída da coalescência das cavidades. Os solos apresentam mineralogia pouco comum para solos tropicais, com

  19. Inibição da Na+/K+ATPase pelo derivado esteróide auabaína: Implicações sobre o ciclo de vesículas sinápticas em junção neuromuscular.

    OpenAIRE

    Ernani Aloysio Amaral

    2006-01-01

    Ouabaína é um derivado esteróide cardiotônico e inibidor específico da Na+K+-ATPase. Neste trabalho, os efeitos da ouabaína sobre o ciclo de vesículas sinápticas na junção neuromuscular de rã foram investigados de forma direta e dinâmica utilizando-se a sonda fluorescente FM1-43. Este marcador consiste em uma molécula anfipática com uma cauda hidrofóbica que promove a ligação da sonda à membrana do terminal axonal. Após um estímulo despolarizante, a membrana marcada com FM1-43 é internalizada...

  20. El papel de la contabilidad en procesos derivados de irregularidades en la gestión de rentas y reclamación de alcances. La contabilidad del Refitor de la Catedral de Toledo Gonzalo Patiño (1582-1583

    Directory of Open Access Journals (Sweden)

    Susana Villaluenga

    2012-12-01

    En torno al cargo y data, un método más jurídico que contable, se articulaba un sistema de garantías que salvaguardaba los intereses del titular del negocio. Así, tomando como base los registros contables del refitor de la Catedral de Toledo entre 1582 y 1583, este trabajo pretende ser un ejemplo del papel que desempeñaba esta forma de llevar la cuenta en procesos derivados de irregularidades en la gestión de rentas y reclamación de alcances. Esto aunque el método contable utilizado a diario en la oficina fuera la partida doble.

  1. Irradiation of Poultry and Egg Products; Irradiation de la Volaille et des Ceufs et Derives; Obluchenie domashnej ptitsy, yaits i izdelij iz nikh; Irradiacion de Volateria, Huevos y Productos Derivados

    Energy Technology Data Exchange (ETDEWEB)

    Thornley, Margaret J. [Sub-Department of Chemical Microbiology, Department of Biochemistry, University of Cambridge, Cambridge (United Kingdom)

    1966-11-15

    , tout en retardant de 1,5 a 3 fois la corruption microbienne. La conservation sous refrigeration (5 Degree-Sign C ou au-dessous) est necessaire, et cette duree peut etre abregee par l'alteration du gout, de telle sorte que 20 jours a 1 Degree-Sign C est a peu pres le maximum que l'on puisse obtenir sans alteration de la qualite. Le mecanisme de ces changements reste inexplique, mais on sait qu'ils ne sont pas dus a des agents microbiens ni a l'irradiation. La corruption par les microbes de poulets irradies sous refrigeration est due a des bacteries non pathogenes normalement presentes dans la flore corruptrice; toutefois, les proportions des differentes sortes de bacteries peuvent varier, donnant ainsi differentes alterations de l'odeur. L'utilisation de ce procede dans les conditions existant au Royaume-Uni en matiere de production et de distribution des poulets a rotir a ete etudiee, et la Commission de l'energie atomique des Etats-Unis, l'Atomic Energy of Canada Ltd., et les laboratoires de l'United States Army Material Command (Natick) examinent conjointement le probleme. Ces etudes portent sur les besoins et les avantages economiques, l'innocuite, l'elaboration de nouveaux produits, le conditionnement et l'accueil du consommateur. (author) [Spanish] La volaterfa, los huevos y sus derivados pueden someterse eficazmente a diferentes procesos de irradiacion, segun las circunstancias. Cuando el problema consiste en la contaminacion por Salmonella, puede practicarse la ' radicidacion' con dosis del orden de 0,5 Mrad. Esto es particularmente util cuando se trata de productos congelados, tales como huevos enteros y algunas variedades de aves, en particular los patos. Los huevos desecados y sus derivados pueden tambien tratarse por este procedimiento. Otros autores (Ley, Mossel [2,3] ) describen detalladamente esta aplicacion. El tratamiento de aves sacrificadas para poder almacenarlas durante tiempo indefinido (' radappertizacion') puede efectuarse con dosis de 4,5 Mrad

  2. AVALIAÇÃO IN VITRO DA AÇÃO DA QUITOSANA E DE SEU DERIVADO QUATERNIZADO NA INIBIÇÃO DO CRESCIMENTO DO FUNGO PENICILLIUM EXPANSUM / IN VITRO EVALUATION OF CHITOSAN AND ITS QUATERNIZED DERIVATIVE ON THE INHIBITION OF PENICILLIUM EXPANSUM GROWTH

    Directory of Open Access Journals (Sweden)

    L. D. Mendes

    2016-03-01

    Full Text Available Quitosana comercial de média massa molar (400.000 gmol-1e seu derivado quaternizado hidrossolúvel N,N,N-trimetilquitosana foram avaliados em condições laboratoriais, em análises in vitro, como agentes inibidores do crescimento de Penicillium expansum. Formulações nas concentrações de 0,1; 1,0; 5,0 e 10,0 gL-1 de cada polímero foram preparadas e adicionados em meio de cultura BDA sólido e aquoso. O fungo foi isolado de frutas contaminadas, cultivado e inoculado nos meios contendo os polímeros. Análises conduzidas por medida do crescimento de colônias em meio sólido e por contagem de esporos germinados em meio liquido (em câmara de Neubauer indicaram eficiência na redução da infestação por ambos os polímeros, porém em condições distintas. A quitosana apresentou elevada eficiência em meio líquido enquanto seu derivado foi eficaz na redução do crescimento em meio de cultura sólido, ambos em baixas concentrações (0,1 e 1,0 gL-1. Os resultados são discutidos com base nos mecanismos aceitos de ação antimicrobiana da quitosana, objetivando potenciais aplicações tópicas em frutos na condição pós-colheita.

  3. Avaliação dos parâmetros derivados do eletroencefalograma durante administração de diferentes concentrações de óxido nitroso Evaluación de los parámetros derivados del electroencefalograma durante administración de diferentes concentraciones de óxido nitroso Evaluation of electroencephalographic parameters during the administration of different nitrous oxide concentrations

    Directory of Open Access Journals (Sweden)

    Sara Lúcia Cavalcante

    2003-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: A análise espectral do eletroencefalograma vem sendo usada como medida da profundidade anestésica, nível de hipnose e sedação de diversos agentes anestésicos. O objetivo deste estudo foi avaliar os efeitos do N2O sobre os parâmetros derivados do eletroencefalograma, nível de sedação pela Escala Analógica de Alerta e Sedação (EAS, variáveis hemodinâmicas e ventilatórias. MÉTODO: Participaram do estudo 30 pacientes adultos, de ambos os sexos, estado físico ASA I, com idades entre 20 e 40 anos, que se submeteram ao seguinte protocolo: respirar espontaneamente e relaxar de olhos fechados durante dez minutos, sendo coletados dados em três momentos: M1 - antes da oferta de N2O; M2 - N2O a 30% em O2; M3 - N2O a 50% em O2. A coleta dos dados de M2 e M3 foi realizada após quinze minutos da estabilização das frações expiradas de N2O (FeN2O em 30% e 50% respectivamente, com o tempo de 5 minutos entre as frações. Os parâmetros estudados foram os seguintes: eletroencefalográficos: BIS, SEF1, SEF2, potência total (PT e taxa de supressão (TS; hemodinâmicos: freqüência cardíaca (FC, pressão arterial sistólica (PAS, pressão arterial diastólica (PAD; ventilatórios: SpO2, P ET CO2, ventilação minuto e freqüência respiratória; clínicos: os pacientes foram classificados numericamente em ordem decrescente (5, 4, 3, 2 e 1 quanto ao seu estado de alerta, pela EAS. RESULTADOS: O N2O a 30% e a 50% modificou estatisticamente o BIS, SEF1, SEF2, PT e o grau de sedação pela EAS, ao longo dos momentos estudados. Não foram observadas modificações clinicamente importantes, pois todos os pacientes mostraram-se cooperativos e levemente sedados, apesar das variações do SEF1 e SEF2 indicarem valores compatíveis com estágio de hipnose profunda. As variações estatísticas nos parâmetros hemodinâmicos e ventilatórios não foram clinicamente significativas. CONCLUSÕES: O N2O a 30% e a 50%, em

  4. Exploración del efecto protector frente a radicales libres de derivados de la uva (Vitis vinifera L. Cv. Tannat en Saccharomyces cerevisiae Analysis of a putative protection against free radicals by grape derivatives (Vitis vinifera L. Cv. Tannat in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    N. Bracesco

    2007-03-01

    Full Text Available Se exploró un posible efecto protector del genoma por parte de un derivado de la uva (vino Tannat. Se utilizaron poblaciones celulares haploides y diploides de Saccharomyces cerevisiae como modelo eucariota. Muestras celulares se expusieron a H2O2 en medio nutriente. El ADN se analizó por densitometría láser, luego de su aislamiento y separación por electroforesis con campos pulsados. Se aplicó la distribución de Poisson para la determinación de roturas dobles. El número de roturas dobles del ADN y la frecuencia mutagénica aumentaron en función de la dosis de H2O2, disminuyendo la probabilidad de sobrevida. La combinación de H2O2 con vino Tannat aumentó significa-tivamente la probabilidad de sobrevida y disminuyó el número de roturas dobles. No se observó efecto mutagénico por el vino Tannat. Estos efectos pudieron simularse utilizando altas concentraciones de α-tocoferol. Los resultados indican que un derivado de Vitis vinifera puede, en ciertas condiciones, disminuir las dobles roturas de ADN producidas por el H2O2 e incrementar las probabilidades de sobrevida celular. Los blancos involucrados podrían ser, entre otros, componentes intracelulares de las cascadas redox y/o enzimas de reparación del ADN.The aim of this work was to analyse a possible genome protection provided by a grape derivative (Tannat wine in yeast cell populations exposed to H2O2. Haploid and diploid strains of Saccharomyces cerevisiae were used as eukaryotic model. Cell samples were exposed to H2O2 in a nutrient medium. Chromosomal DNA was analysed after isolation and separation by pulsed field electrophoresis. Double strand breaks were determined by laser densitometry and application of Poisson distribution. Both haploid and diploid cells showed H2O2 dose dependent DNA fractionation, as well as an increase of lethal -and mutation- events. Upon combination of the Tannat wine and H2O2 a significant decrease of double strand breaks was observed, in

  5. Brain-derived neurotrophic factor gene val66met polymorphism and executive functioning in patients with bipolar disorder Polimorfismo do gene do fator neurotrófico derivado do cérebro val66met e função executiva em pacientes com transtorno bipolar

    Directory of Open Access Journals (Sweden)

    Juliana Fernandes Tramontina

    2009-06-01

    Full Text Available OBJECTIVE: In the present study, we investigate the association between the val66met polymorphism of the brain-derived neurotrophic factor (BNDF and the performance on the Wisconsin Card Sorting Test in a sample of Caucasian Brazilian patients with bipolar disorder. METHOD: Sixty-four patients with bipolar disorder were assessed and their performance on the Wisconsin Card Sorting Test was compared with the allele frequency and genotype of the val66met polymorphism of the brain-derived neurotrophic factor. RESULTS: The percentage of non-perseverative errors was significantly higher among patients with the val/val genotype. There was no association between (BNDF genotype frequency and other Wisconsin Card Sorting Test domains. CONCLUSION: Our results did not replicate previous descriptions of an association between a worse cognitive performance and the presence of the met allele of the val66met brain-derived neurotrophic factor gene polymorphism.OBJETIVO: O presente estudo tem por objetivo investigar a associação entre o polimorfismo val66met do gene do fator neurotrófico derivado do cérebro (BDNF e o desempenho cognitivo no Teste Wisconsin de Classificação de Cartas em uma amostra de pacientes bipolares brasileiros caucasianos. MÉTODO: Sessenta e quatro pacientes com transtorno bipolar foram avaliados em relação a sua cognição por meio do Teste Wisconsin de Classificação de Cartas que foi comparada com a freqüência alélica e genotípica do polimorfismo val66met do gene do fator neurotrófico derivado do cérebro. RESULTADOS: O percentual de erros não-perseverativos foi significativamente maior nos indivíduos com genótipo val/val. Não foi encontrada diferença significativa entre a freqüência genotípica do polimorfismo do BDNF e os outros domínios do Teste Wisconsin de Classificação de Cartas. CONCLUSÃO: O estudo do polimorfismo val66met em relação ao desempenho executivo em pacientes bipolares caucasianos de uma

  6. Obtenção de derivado de celulose a partir do bagaço de cana-de-açúcar com potencial aplicação nas indústrias farmacêutica e cosmética

    Directory of Open Access Journals (Sweden)

    DANYELLA MARçAL SILVA

    2011-06-01

    Full Text Available A tendência de se buscar o desenvolvimento de novos veículos agregando sustentabilidade e qualidade é o desafio da pesquisa farmacêutica. Assim, a busca de novas fontes de matéria-prima parece ocupar uma grande parcela dos estudos e investimentos do setor farmacêutico. Desse modo, a celulose é um exemplo de matéria-prima com alta aplicabilidade nas indústrias farmacêutica e cosmética. Temos na natureza algumas espécies de angiospermas com potencial fornecimento de celulose, tais como coco, bambu, cana-de-açúcar, entre outras. Destas, o bagaço de cana-de-açúcar apresenta teores de celulose significativos para obtenção de compostos derivados. O Brasil ocupa o primeiro lugar na produção de etanol e açúcar através da utilização da cana-de-açúcar. O presente trabalho teve como objetivo avaliar uma dispersão obtida a partir de um composto derivado da celulose extraída do bagaço de cana-de-açúcar. Palavras-chave: Bagaço de cana-de-açúcar. Subprodutos. Celulose. Géis. ABSTRACT Assessment of a gel derived from sugarcane bagasse cellulose The development of new vehicles combining sustainability and quality is a challenge facing pharmaceutical research. Thus, the search for novel raw material sources seems to occupy a great portion of the studies and investments of the pharmaceutical sector. One example of such a raw material with wide applicability in the pharmaceutical and cosmetics industries is cellulose. There are several angiosperm species with potential as suppliers of cellulose, such as coconut, bamboo and sugarcane, to name a few found in Brazil. Bagasse, the fibrous residue from crushed sugarcane, has a significant cellulose content from which new compounds can be derived. Brazil currently occupies first place in the production of ethanol and sugar from sugarcane. The aim of the present study was to assess a dispersion obtained from a derivative of the cellulose extracted from sugarcane pulp. Keywords

  7. 1-N-aminoindol derivatives synthesis in no aqueous means from the 1, 4-dihydrocinnoline obtained by electrolysis in continuous flow redox cell; Sintesis de derivados del 1-N-aminoindol en medios no acuosos a partir de la 1, 4-dihidrocinolina obtenida por electrolisis en celda redox de flujo continuo

    Energy Technology Data Exchange (ETDEWEB)

    Frontana-Uribe, Bernardo A. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Moinet, Claude [Laboratoire d' Electrochimie et Organometalliques UMR, Paris (France)

    1999-08-01

    This work describes the synthesis of 1-N-aminoindol derivatives in organic anhydrous media from 1, 4-dihydrocinnoline. 1, 4-dihydrocinnoline 4 is obtained by electrolysis of 2-(orto-notropheny)-ethylamine 1a in a continuous flow redox cell. The cinnoline ring contraction products are obtained in low yield, but they show the possibility to carry out the reaction in organic media without water addition, as it was noted in previous works. [Spanish] En este trabajo se describe la sintesis de derivados del 1-N-aminoindol en medios anhidros a partir de la 1, 4-dihidrocinolina 4. Esta se obtiene mediante la electrolisis de la 2-(orto-notrofenil)-etilamina 1a en celda redox de flujo continuo. Los productos de contraccion del ciclo de la cinolina en 1-N-aminoindol se obtiene en rendimiento bajo, pero demuestran la posibilidad de llevar a cabo esta reaccion en medios totalmente organicos, sin la necesidad de la adicion de agua en el medio de reaccion, como esta descrito en trabajos precedentes.

  8. MODELOS Y TEORÍAS (MyT EN LAS ORGANIZACIONES EDUCATIVAS. Resultados derivados en hipótesis desde una investigación realizada para comprender la aplicación de las teorías en la escuela y en el aula

    Directory of Open Access Journals (Sweden)

    William Mantilla Cárdenas

    2006-01-01

    Full Text Available Este artículo es un resultado derivado de un conjunto de estudios realizados con procesos de investigación participante y de investigación acción en instituciones educativas, tanto públicas como privadas. Se presenta la forma en que circulan y se asimilan modelos y teorías (MyT por parte de los actores institucionales y de la organización educativa en su conjunto. De allí se deriva la perspectiva de la organización como teoría, con base en una tesis de la organización construida por los actores a partir de la integración, la asimilación, la hibridación y otras acciones que se suceden para este fin. El efecto enriquecedor del resultado de investigaci ón se puede situar en la manera en que sucede la reforma educativa en términos teóricos para las organizaciones.

  9. Pervaporation de melange eau-ethanol a travers des membranes en alcool polyvinylique

    Directory of Open Access Journals (Sweden)

    Mahacine Amrani

    2006-01-01

    Full Text Available La deshidratación del etanol a partir de una mezcla de composición azéotropica (4,4% en masa de agua fue efectuada por paso en una unidad de pervaporación a través de una membrana orgánica a base de alcohol polivinilo PVA. La pervaporación es un método de separación por membrana utilizado para las mezclas líquidas difíciles a tratar por los métodos convencionales. Se efectuaron algunas pruebas de pervaporación a través de membranas de PVA puro con el fin de poner de relieve la influencia de tales parámetros: el tipo de acetilación de las membranas, el tratamiento de colodión generador, el acondicionamiento de las películas membranarias así como la temperatura de la carga. El aumento del tipo de acetilación mejora el flujo de transferencia pero vuelve la membrana difícilmente manipulable. El tratamiento del colodión generador así como el acondicionamiento de las membranas a base de PVA4 aumentan el flujo de pervaporación de la mezcla agua-etanol sin que la selectividad se afecte demasiado. La variación de la temperatura de la carga nos permite determinar la energía de activación de la membrana

  10. Pervaporation de melange eau-ethanol a travers des membranes en alcool polyvinylique

    OpenAIRE

    Mahacine Amrani

    2006-01-01

    La deshidratación del etanol a partir de una mezcla de composición azéotropica (4,4% en masa de agua) fue efectuada por paso en una unidad de pervaporación a través de una membrana orgánica a base de alcohol polivinilo PVA. La pervaporación es un método de separación por membrana utilizado para las mezclas líquidas difíciles a tratar por los métodos convencionales. Se efectuaron algunas pruebas de pervaporación a través de membranas de PVA puro con el fin de poner de relieve la in...

  11. ALCOol, vigiLAnce, Charge de travail : facteurs d'accident chez les jeunes conducteurs

    OpenAIRE

    BERTHELON, Catherine; GALY, Edith; PAXION, Julie; Ferrier, Laurent

    2016-01-01

    D'après le modèle de courbe en U renversé d'Ansseau et Timsit-Berthier (1987 ; in Hadj-Mabrouk, 2001), le niveau de performance augmente avec celui de la vigilance jusqu'à un optimum, au-delà de cet optimum l'augmentation de la vigilance entraîne au contraire une baisse de la performance. L'excès de vigilance que représentent la tension (stress) ou l'hyperexcitation a un pouvoir de dégradation plus rapide sur les activités complexes que sur les activités les plus simples. Il y a donc un nivea...

  12. Alcohol as international commodity; Alcool como 'commodity' internacional

    Energy Technology Data Exchange (ETDEWEB)

    Negrao, Luiz Celso Parisi [Ministerio do Desenvolvimento, Industria e Comercio Exterior, Brasilia, DF (Brazil). Secretaria de Tecnologia Industrial]. E-mail: luiz.negrao@desenvolvimento.gov.br; Urban, Maria Lucia de Paula

    2004-12-15

    The ethanol is able to reduce the gas emissions, mainly in CO2 balance which gives a strong contribution for this fact. Using the alcohol rather than fossil fuels is a natural choice as a important renewable energy source. Also, to have the alcohol as international environmental commodity is the goal of all interested in this matter, since the entry into force the Kyoto protocol, with the Russian approval.

  13. Literacia em saude mental de adolescentes e jovens portugueses sobre abuso de alcool

    Directory of Open Access Journals (Sweden)

    Luis Manuel de Jesus Loureiro

    2013-09-01

    Full Text Available OBJETIVO: Caracterizar a literacia em saúde mental de adolescentes e jovens relativamente ao consumo abusivo de álcool, nas diversas componentes do conceito de literacia. MÉTODOS: Estudo descritivo-exploratório, em que foi aplicado o QuALiSMental a uma amostra representativa de 4.938 adolescentes e jovens, com idades compreendidas entre os 14 e os 24 anos, que frequentam escolas do 3º ciclo do ensino básico e do ensino secundário da região centro de Portugal. RESULTADOS: O reconhecimento da vinheta do consumo abusivo de álcool pelos participantes é elevado (72,4%, ainda que seja também identificado como alcoolismo (70,3%, o que no entanto indica a percepção do problema como grave. Os participantes apresentam níveis modestos de literacia nas restantes componentes, preferindo as fontes informais de ajuda. CONCLUSÃO: Conclui-se que há necessidade de implementação de programas nas escolas que promovam a literacia em saúde mental, para adoção de comportamentos saudáveis nos jovens, que os transferem para a idade adulta.

  14. Épidémiologie de la consommation d'alcool par les femmes ...

    African Journals Online (AJOL)

    SARAH

    31 août 2014 ... Methodology and results: A survey was conducted in health centers in the city of Abidjan. This survey ... Conclusion and application of results: On these grounds, the state should start a campaign to raise awareness ... association de retard mental et de dysmorphie ..... Préférence et consommation effective.

  15. Obtención y evaluación de un derivado proteico purificado de una cepa argentina de Mycobacterium avium subsp. paratuberculosis Production and evaluation of a purified protein derivative from an Argentine strain of Mycobacterium avium subsp. paratuberculosis (MAP

    Directory of Open Access Journals (Sweden)

    Andrea Gioffré

    2012-09-01

    Full Text Available Los derivados proteicos purificados (PPD son mezclas antigénicas no definidas obtenidas de distintas micobacterias. Los PPD bovino (PPDb y PPD aviar (PPDa son los antígenos que se emplean para evaluar la respuesta inmunitaria celular en infecciones como tuberculosis y paratuberculosis en el bovino. El PPDa comercial se produce a partir de Mycobacterium avium subsp. avium, y no a partir de la subespecie paratuberculosis. En este trabajo se seleccionó una cepa local de Mycobacterium avium subsp. paratuberculosis cuyo patrón molecular por RFLP es el más frecuente entre los aislamientos de nuestro país que han sido estudiados, y a partir de esta, se obtuvo un derivado proteico purificado: PPDj-IB. Se emplearon tanto el PPDa comercial como el PPDj-IB como antígenos en la prueba de liberación de gamma-interferón en animales de un tambo con paratuberculosis y en animales control. Aun cuando ambos PPD fueron capaces de estimular diferencialmente la liberación de la citoquina en el tambo infectado (respecto de los tambos control, no hubo diferencias significativas en los niveles de estimulación producidos y solo dos animales fueron positivos mediante el empleo de PPDj-IB. A partir del análisis por Western blot se demostró que el contenido de lipoarabinomano y del antígeno Apa/ModD era distinto en los PDD evaluados. Estas diferencias podrían explicar, en parte, las diferencias en los niveles de estimulación en términos individuales. Si bien el empleo de PPDj-IB no mejoró significativamente los resultados de la prueba de liberación de ?IFN, es importante destacar que se logró producir en el laboratorio un PPD apto para su empleo en ensayos in vitro.Purified Protein Derivatives (PPDs are non-defined antigens prepared from mycobacteria cultures. They are usually employed to evaluate the specific cellular immune response both in animals and humans. Bovine and avian PPDs are usually employed as antigens in mycobacterial infections such as

  16. Ingestão de nutrientes e estado nutricional de crianças em dieta isenta de leite de vaca e derivados Nutrient intake and nutritional status of children following a diet free from cow's milk and cow's milk by-products

    Directory of Open Access Journals (Sweden)

    Lilian C. S. Medeiros

    2004-01-01

    Full Text Available OBJETIVO: Avaliar a ingestão alimentar e o estado nutricional de crianças em dieta isenta de leite de vaca e derivados. MÉTODOS: Foram avaliadas 26 crianças, na primeira consulta realizada em ambulatório de gastroenterologia pediátrica, que vinham recebendo dieta isenta de leite de vaca e derivados (média de idade = 19,1 meses e 30 crianças com dieta normal, isto é, sem nenhum tipo de restrição alimentar (média de idade = 16,8 meses. Empregou-se o método do dia alimentar habitual para a obtenção dos dados sobre consumo alimentar. A ingestão alimentar foi comparada entre os grupos e em relação às Dietary Reference Intakes (DRIs. O estado nutricional foi avaliado com base nos escores z de peso/idade, estatura/idade e peso/estatura. RESULTADOS: O grupo em dieta isenta de leite de vaca apresentou menor ingestão de energia (p = 0,005, proteínas (p OBJECTIVE: To assess the food intake and the nutritional status of children on a cow's milk and cow's milk by-products free diet. METHODS: Twenty-six children receiving a cow's milk and cow's milk by-products free diet were assessed during their first visit to the Pediatric Gastroenterology Clinic (mean age = 19.1 months. Thirty children with no food restriction (mean age = 16.8 months were also assessed. The usual daily food intake method was used to make the dietary assessment. The food intake was compared between the groups and in relation to the Dietary Reference Intakes (DRIs. The z-scores for weight/age, height/age and weight/height were used to evaluate the nutritional status. RESULTS: The cow's milk free diet group presented lower energy (p = 0.005, protein (p < 0.001, lipid (p < 0.001, calcium (p < 0.001 and phosphorous (p < 0.001 intake when compared to the control group. The number of children who had energy, calcium and phosphorous intake below the DRIs was higher in the cow's milk free diet group than in the control group. The z-score means for the cow's milk free diet and

  17. Ecología trófica de Girella laevifrons (Pisces: Kyphosidae en zonas intermareales rocosas del norte de Chile afectadas y no afectadas por contaminantes derivados de la minería del cobre Trophic ecology of Girella laevifrons (Pisces: Kyphosidae in rocky intertidal zones of northern Chile affected an non-affected by copper mine tailings

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    JOSE MIGUEL FARIÑA

    2000-03-01

    Full Text Available La zonas intermareales de localidades de la costa norte de Chile afectadas por contaminantes derivados de la minería del cobre, presentan una diversidad de especies sésiles menor que las localidades no afectadas. Girella laevifrons es un pez altamente representado en zonas intermareales rocosas del norte de Chile. En el presente trabajo se analiza y compara la ecología trófica de esta especie, en relación con las diferencias en la composición de especies sésiles de sitios contaminados y no contaminados. Los resultados muestran diferencias significativas en la composición trófica de los ejemplares presentes en los sitios afectados y no afectados. Dentro de los sitios afectados, se observan diferencias en los tamaños y en las concentraciones de cobre corporales, las cuales pueden estar relacionadas directamente con la disponibilidad de alimento e indirectamente con interacciones con otros organismos intermarealesThe intertidal zone at several sites of the northern Chilean coast affected by copper mine tailings, shows a lower diversity of sessile species than the non-affected ones. Girella laevifrons is a fish highly represented in rocky intertidal shores of these sites. In this study we analized and compared, the dietary composition of this species and its relation with the intertidal sessile assemblages of contaminated and non-contaminated sites. The results show significant differences in the dietary composition of the fishes occurring in contaminated and non-contaminated sites. Within the contaminated sites, the differences in body sizes and in the body concentrations of copper could be related directly to the food availability and indirectly to the interactions with other intertidal species

  18. Avaliação de derivados poliméricos intercalados em montmorilonita organofílica na preparação de novos materiais de uso farmacêutico Evaluation of use of organophilic montmorillonite and its polymeric intercalated derivatives in preparation of new pharmaceutical materials

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    Camila B. Dornelas

    2008-09-01

    Full Text Available A nanotecnologia está relacionada às estruturas, propriedades e processos envolvendo materiais com dimensões numa escala nanométrica. O conceito de nanotecnologia em aplicações farmacêuticas, mais especificamente na liberação de fármacos, está baseado na produção de nanopartículas que contêm moléculas do fármaco a serem depositadas exclusivamente no órgão ou tecido alvo com a vantagem de serem inativas. Neste contexto, o presente trabalho busca estudar a utilização de uma organoargila, previamente modificada com octadecilamina, viscogel B8, como matriz de liberação controlada de fármacos por meio da reação de intercalação desta argila com PEG 6000 e MEG, comparando-se os resultados obtidos com um derivado previamente obtido da intercalação desta argila com PVP K-30. Estes materiais têm como diferencial a reunião de diferentes aspectos de funcionalidade, possibilitando se obter excipientes de liberação modificada de propriedades mistas.Nanotechnology is related to structures, properties and processes involving materials in a nanometer dimension. This is widely used for pharmaceutical applications, more specifically in drugs' release. In this context, the present work studies the use of organophilic montmorillonite (OMMT, viscogel B8, as matrix of controlled release of drugs. New polymer-layered silicate nanocomposites (PLN of MEG, PEG 6000 and OMMT were prepared and compared with PVP K-30-OMMT.

  19. Influence of the type of cellulosic derivatives on the texture, and oxidative and thermal stability of soybean oil oleogel; Influencia del tipo de derivado celulósico sobre la textura y la estabilidad oxidativa y térmica de oleogeles de aceite de soja

    Energy Technology Data Exchange (ETDEWEB)

    Totosaus, A.; Gonzalez-Gonzalez, R.; Fragoso, M.

    2016-07-01

    The use oleogels (defined as edible oils entrapped in a three-dimensional network employing a self-assembled structuring agent) has recently been proposed to replace saturated fat or trans-fats in foods. In this work the effects of different cellulose derivative mixtures (Avicel, ethyl cellulose and a-cellulose) on lipid stability, glass transition temperature and the texture of soybean oil oleogels were determined by employing a mixture design approach. Avicel affected lipid stability, increasing the oxidative rancidity and peroxide values of oleogels. Oleogels with higher proportions of Avicel also presented higher transition temperatures. A higher percent of ethyl cellulose and a-cellulose in the oleogel mixture resulted in a more stable system with lower oil rancidity and lower glass transition temperatures. In addition, Avicel resulted in a softer and less tacky texture, an important characteristic to consider for food applications. [Spanish] Recientemente, ha sido propuesto el uso de oleogeles (definido como aceites comestibles atrapados en una red tridimensional que ocupa un agente estructurante de auto-ensamblado) como substituto de grasa saturada o grasas trans en alimentos. En este trabajo el efecto de mezclas de diferentes derivados celulósicos (Avicel, etil celulosa y a-celulosa) sobre la estabilidad de lípidos, temperaturas de transición térmica y textura de oleogeles de aceite de soja fueron determinados utilizando un diseño de mezclas. Avicel afectó la estabilidad de lípidos, aumentando la rancidez oxidativa y valores de peróxido en los oleogeles. Oleogeles con mayores proporciones de Avicel también presentaron temperaturas de transición térmica más altas. porcentajes más altos de etil celulosa y a-celulosa resultaron en un sistema más estable con menor rancidez oxidativa y menores temperaturas de transición térmica. Sin embargo, Avicel resultó en una textura más suave y menos pegajosa, una característica importante a considerar

  20. Ativador do Plasminogênio Tecidual (tPA/ Fator Neurotrófico Derivado do Cérebro (BDNF e a Consolidação da Memória/ Tissue Plasminogen Activator (tPA/ Brain Derived Neurotrophic Factor (BDNF and the Consolidation of Memory

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    Rodolfo Souza de Faria

    2014-09-01

    Full Text Available O Fator Neurotrófico Derivado do Cérebro (BDNF participa de processos de plasticidade sináptica subjacentes à aprendizagem e memória. Esta proteína possui diversas isoformas, sendo a isoforma BDNF-maduro envolvida nas mudanças neuronais da memória. Além disso, foi demonstrado que a consolidação da memória aversiva depende do Ativador do Plasminogênio Tecidual (tPA, enzima que estabelece a formação do BDND-maduro na fenda sináptica garantindo os processos neuroplásticos da aprendizagem. Para esta revisão de literatura, foram selecionados 37 trabalhos, dentre eles 36 artigos científicos e 1 livro. A consolidação da memória requer a ativação gênica para síntese de novas proteínas, sendo a tPA e o BDNF algumas das principais moléculas neuronais expressas no hipocampo, amigdala, córtex frontal em diferentes momentos após o início da aprendizagem, ativando uma série de eventos moleculares que levam ao aumento da expressão de outras proteínas, garantindo assim a regulação fina da plasticidade neuronal necessária para a memória. The Brain Derived Neurotrophic Factor (BDNF participates in synaptic plasticity processes underlying learning and memory. This protein has several isoforms, mature-BDNF one isoform involved in neuronal memory changes. Furthermore, it was demonstrated that the consolidation of aversive memory depends on the tissue plasminogen activator (tPA, an enzyme that establishes the formation of the mature BDND-synaptic cleft, guaranteeing neuroplastic learning processes. For this literature review, we selected 37 works, including 36 scientific articles and one book. The consolidation of memory for gene activation requires new protein synthesis, tPA and BDNF and some of the major neuronal molecules expressed in the hippocampus, amygdala, frontal cortex at different times after the start of learning, activating a series of molecular events leading the increased expression of other proteins, thereby

  1. SÍNTESIS ESTEREOSELECTIVA DE UN NITRO DERIVADO

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    Andres Felipe Sierra

    2011-04-01

    Full Text Available En este trabajo se describen tanto la síntesis como la caracterización de E,E-1,4-dimetoxi- 2,5-bis[2-(4-nitrofeniletenil] benceno, mediante la reacción de acoplamiento cruzado de Heck usando trifenilfosfito como ligante, lo cual –y teniendo en cuenta la literatura científica consultada– es el primer reporte de un doble acoplamiento de Heck empleando fosfitos como ligante en la formación del complejo catalítico con paladio. La caracterización del sistema fenilvinilideno obtenido muestra que el mecanismo es altamente estereoselectivo hacia la formación de enlaces trans, y su altísimo rendimiento (98% indica que el sistema catalítico es bastante promisorio para realizar multiacoplamientos cruzados necesarios para obtener polímeros fenilvinilideno con altos pesos moleculares y altas eficiencias en las propiedades optoelectrónicas, necesarios para la tecnología de la electrónica de polímeros.

  2. Estudios sobre la fisostigmina (eserina y productos derivados

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    Gonzalo Montes D.

    1943-01-01

    Full Text Available En los últimos años se han desarrollado trabajos que muestran claramente cómo los efectos del sistema nervioso parasimpátíco se producen mediante la liberación de una substancia química en las terminaciones nerviosas, la cual es directamente responsable de la excitación de las células inervadas. Esta substancia tiene acción idéntica a la de la acetilcolina. Como trabajos básicos en el descubrimiento de este mecanismo deben citarse los de Loewi, quien probó que la estimulación del vago en el corazón aislado de la rana producía acetilcolina, mientras que la estimulación del simpático liberaba una substancia semejante a la adrenalina. Este descubrimiento fué luégo confirmado por otros investigadores en otros órganos aislados y ha servido para sentar la teoría hormonal del control autónomo.

  3. Biofuels derived from corn; Biocombustibles derivados del maiz

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu Fernandez, Jose Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2012-06-22

    The biofuels can be obtained from the biomass, are liquid, solid or gaseous from matter of vegetal or animal origin, by biological, chemical or physical processes and combinations of them. The biofuels appear as an alternating fuels in the transport sector, mainly due to the positive impact of greenhouse gases effect (GHG) and to the increase of oil prices. In theory the use of bioethanol and the biofuels, they not have CO{sub 2} emissions since this it is absorbed in the same amount by the cultures that generate them, as the corn or sugar cane. Our country has a deficit in the food production, mainly in corn, grain that can offer the opportunity not only to continue being the base of the national feeding, but also the raw material to produce bioethanol. The national yields are so diverse that they resemble to those of EUA or Africa, without a doubt this is indicative that is due to devise the way of increase the yields of this appraised culture, reach in average the six tons by hectare, improving the culture practice and access to fertilizers, water, transport, transparent markets and right prices. [Spanish] Los biocombustibles pueden ser obtenidos de la biomasa, son liquidos, solidos o gaseosos provenientes de material vegetal u origen animal, pueden obtenerse mediante procesos biologicos, quimicos o fisicos, y combinaciones de ellos. Se presentan como combustibles alternos en el sector transporte, debido principalmente al impacto positivo de la reduccion de gases de efecto invernadero (GEI) y al aumento de los precios del petroleo. En teoria el uso del bioetanol y los biocombustibles no produce emisiones de CO{sub 2} porque este se absorbe en la misma cantidad a traves de los cultivos que los generan, como el maiz y la cana de azucar. Mexico tiene deficit en la produccion de alimentos, principalmente maiz, grano que puede ofrecer la oportunidad no solo de continuar siendo la base de la alimentacion nacional, sino tambien la materia prima para producir bioetanol. Las cosechas nacionales son tan diversas que se asemejan a las de EUA o Africa, sin duda de que esto es indicativo de que se debe idear la manera de aumentar las cosechas de este valorado cultivo, alcanzando las seis toneladas por hectarea mediante el mejoramiento de las practicas de cultivo y el acceso a fertilizantes, agua, transporte, mercados transparentes y precios justos.

  4. SÍNTESIS ESTEREOSELECTIVA DE UN NITRO DERIVADO

    OpenAIRE

    Andres Felipe Sierra; Ricaurte Rodriguez; Cesar Sierra

    2011-01-01

    En este trabajo se describen tanto la síntesis como la caracterización de E,E-1,4-dimetoxi- 2,5-bis[2-(4-nitrofenil)etenil] benceno, mediante la reacción de acoplamiento cruzado de Heck usando trifenilfosfito como ligante, lo cual –y teniendo en cuenta la literatura científica consultada– es el primer reporte de un doble acoplamiento de Heck empleando fosfitos como ligante en la formación del complejo catalítico con paladio. La caracterización del sistema feni...

  5. Derivados cárnicos como alimentos funcionales

    OpenAIRE

    Ospina Meneses, Silvia Marcela; Restrepo Molina, Diego Alonso; López Vargas, Jairo Humberto

    2011-01-01

    In recent years, nutrition and food sciences have been studying the relationship between health and food consumption, concluding that healthy consumption helps to cure and prevent some chronic diseases. Healthy feeding has been based on combining food, nutrients and ingredients added to provide certain healthy conditions, by designing the mixtures for the different physiological situations. Probiotic microorganisms, prebiotics (dietary fiber), some vitamins and minerals, p...

  6. Morfologia e classificação taxonômica de neossolos e saprolitos derivados de rochas vulcânicas da Formação Serra Geral no Rio Grande no Sul Morphology and taxonomy classification of neossolos and saprolites derived from volcanic rock of the Serra Geral formation in Rio Grande do Sul, Brazil

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    Fabrício de Araújo Pedron

    2009-02-01

    Full Text Available Os Neossolos Litólicos e Neossolos Regolíticos são solos pouco estudados no Brasil devido ao seu baixo potencial relativo de uso. Esse fato se reflete em dificuldades na execução da sua descrição morfológica no campo, principalmente no que se refere aos contatos entre solo, saprolito e rocha, e na sua classificação no Sistema Brasileiro de Classificação de Solos. Nesse sentido, os objetivos deste trabalho foram: contribuir na definição morfológica dos contatos entre solo, saprolito e rocha dessas classes de solos no campo; gerar dados sobre a camada saprolítica e testar a sua inclusão na subordem dos Neossolos Litólicos e Neossolos Regolíticos; e avaliar os atributos diagnósticos e classes disponíveis no sistema brasileiro de classificação de solos para a classificação dos Neossolos Litólicos e Regolíticos derivados de rochas vulcânicas da Formação Serra Geral no Rio Grande do Sul. Foram analisados cinco perfis dispostos em uma litoclimossequência. Os contatos foram identificados pelo uso do teste de escavação com a pá reta, associado à análise do fraturamento do saprolito e às classes de intemperismo propostas neste trabalho. Os contatos referentes à presença de camada saprolítica encontrados nos perfis não são contemplados no sistema brasileiro. Foram propostos atributos diagnósticos para a classificação dos Neossolos Regolíticos, sugerindo-se a troca do termo "Regolítico" por "Saprolítico". Também foram sugeridas novas classes para o terceiro nível categórico, considerando informações como posição do contato saprolítico, resistência à escavação e grau de fraturamento do material. Os atributos diagnósticos e as classes propostas permitiram uma classificação mais adequada dos Neossolos derivados de rochas vulcânicas, no Rio Grande do Sul.The soil types Neossolos Litólicos (Leptosols and Neossolos Regolíticos (Regosols have been poorly studied in Brazil, due to their relatively

  7. Serum levels of brain-derived neurotrophic factor and thiobarbituric acid reactive substances in chronically medicated schizophrenic patients: a positive correlation Níveis séricos do fator neurotrófico derivado do cérebro e dos produtos de reação com o ácido tiobarbitúrico em pacientes com esquizofrenia cronicamente medicados: correlação positiva

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    Clarissa Severino Gama

    2008-12-01

    ídica, e o fator neurotrófico derivado do cérebro, a neurotrofina mais amplamente distribuída. MÉTODO: Sessenta pacientes portadores de Esquizofrenia pelo DSM-IV foram incluídos (43 homens, 17 mulheres, com idade média de 34,7 ± 10,8 anos, idade média no primeiro episódio de 19,8 ± 7,9 anos, e tempo médio de duração da doença de 14,9 ± 8,5 anos. Foi coletado sangue de cada sujeito para a determinação dos níveis séricos de fator neurotrófico derivado do cérebro, superóxido-dismutase e ácido tiobarbitúrico. RESULTADOS: Os níveis de fator neurotrófico derivado do cérebro se correlacionaram positivamente aos de ácido tiobarbitúrico (r = 0,333, p = 0,009 e não mostraram correlação com os de superóxido-dismutase (r = - 0,181, p = 0,166. Este último também não se correlacionou aos níveis de ácido tiobarbitúrico (r = 0,141, p = 0,284. CONCLUSÕES: A correlação positiva entre fator neurotrófico derivado do cérebro e ácido tiobarbitúrico direciona para investigações na interação intracelular entre neurotrofinas, enzimas antioxidantes e marcadores de oxidação, além de abrir perspectives para pesquisa em tratamentos para a prevenção da neurotoxicidade ao longo do curso da esquizofrenia.

  8. Composição centesimal e valor protéico de levedura residual da fermentação etanólica e de seus derivados Centesimal composition and protein nutritive value of yeast from ethanol fermentation and of yeast derivatives

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    Eunice Akemi Yamada

    2003-12-01

    Full Text Available Este trabalho teve por objetivo promover a autólise e o fracionamento da levedura (Saccharomyces sp. para produção de autolisado e extrato, bem como para produção de concentrado protéico fosforilado, a partir da levedura residual das destilarias de álcool etílico. Foram estudados a composição centesimal, o perfil de aminoácidos essenciais e o valor protéico dos três derivados comparativamente à levedura íntegra não processada. Proteína e carboidrato (fibra alimentar foram os principais componentes da levedura íntegra e do autolisado. No extrato e no concentrado protéico predominaram proteína e minerais (cinzas. O autolisado e a levedura íntegra apresentaram os melhores índices de aminoácidos essenciais, seguidos pelo concentrado protéico e pelo extrato. A digestibilidade da proteína variou de 68% para a levedura íntegra a 91% para o extrato. Os índices de quociente de utilização líquida da proteína variaram de 2,1 para a levedura íntegra a 4,3 para a caseína (referência. Não houve diferença estatística no quociente de utilização líquida da proteína entre o autolisado (4,1, o extrato (3,9 e o concentrado protéico (4,2. O concentrado protéico promoveu o maior crescimento no período (21 dias, seguido do extrato e o autolisado. As células íntegras apresentaram a menor capacidade para promover crescimento em rato.The objective of this work was to promote the autolysis and the fractionation of the yeast (Saccharomyces sp. for the production of autolysate and extract, as well as phosphorylated protein concentrate, from ethanol distillery yeast. Comparative studies of centesimal composition, essential amino acid profiles and protein nutritive value were performed for the unprocessed integral cells, and for autolysate, extract and phosphorylated protein concentrate. Protein and carbohydrate (dietary fiber were the main components for the integral cells and autolysate. For the extract and the protein

  9. Adaptação de um sistema de ensaio biológico para detecção de fatores relaxantes endoteliais derivados do endocárdio atrial canino Adaptation of bioassay to detect endothelium-derived relaxing factors from the canine atrial endocardium

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    Yeow Leng Chua

    2009-06-01

    Full Text Available OBJETIVO: Estudar a liberação de fatores relaxantes derivados do endotélio (EDRF pelo endocárdio de aurículas de corações caninos. MÉTODOS: Aurículas atriais caninas foram suturadas em forma de tubos e o efluente desses tubos foram submetidos a ensaios biológicos (sistema de perfusão isolada em câmaras de órgãos utilizando artéria coronária canina, para a detecção de EDRFs. RESULTADOS: O efluente da aurícula direita promoveu relaxamento de 58,4 + 10,1% e da aurícula esquerda 74,9 + 8,5% da contração inicial obtida pela ação da prostagladina F2α em artéria coronária. Não houve diferença estatística no relaxamento da artéria coronária induzido pelos efluentes das aurículas direita e esquerda. O relaxamento induzido pelos efluentes das aurículas direita e esquerda foi abolido pelo tratamento das mesmas com Triton X-100. O tratamento das aurículas com L-NMMA, um inibidor competitivo da síntese de óxido nítrico, e com indometacina, um inibidor da via da ciclooxigenase, promoveu redução no relaxamento da artéria coronária induzido pelo efluente auricular, indicando que o endotélio endocárdico libera óxido nítrico e prostanóides. CONCLUSÕES: Esse estudo demonstra, pela primeira vez, a liberação luminal in vitro de EDRF e prostaciclina pelo átrio de coração canino. A habilidade do endotélio endocárdico em produzir esses fatores pode ter um papel importante na prevenção da formação de trombos nas câmaras cardíacas.OBJECTIVE: The aim of this study was to assess the release of endothelium-derived relaxing factors from the endocardium of canine atrial appendage. METHODS: To study the release of endothelium-derived relaxing factor (EDRF from intact atrial endocardial endothelium, tube-shaped sutures of canine atrial appendages were performed and effluents from these tubes were bioassayed (isolated perfused organ chamber system for detection of EDRF in canine coronary artery. RESULTS: Effluent from

  10. Desenvolvimento e validação de um método cromatográfico em fase gasosa para análise da 3,4-metilenodioximetanfetamina (ecstasy e outros derivados anfetamínicos em comprimidos Development and validation of a gas chromatography method for determination of ecstasy and amphetamines derivatives in tablets

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    Marcelo Carvalho Lasmar

    2007-06-01

    Full Text Available O uso abusivo das anfetaminas e seus derivados vêm aumentando dramaticamente nos últimos anos em diversas regiões do mundo, notando-se especial utilização do Ecstasy. A análise de amostras da droga apreendidas nas ruas evidenciou, além da presença de MDMA (3,4-metilenodioximetanfetamina, componente principal da droga, outras feniletilaminas, como a MDA (3,4-metilenodioxanfetamina e MDEA (metilenodioximetiletilanfetamina este último também conhecido como a droga Eve, ainda pouco difundida no Brasil. O objetivo do presente trabalho foi desenvolver e validar um método analítico confiável, prático e acessível aos laboratórios de toxicologia, de médio e pequeno porte, no Brasil e em países em desenvolvimento, para identificação separada do MDMA, MDA e MDEA. A cromatografia em fase gasosa utilizando-se coluna capilar e detector de ionização de chama foi a técnica escolhida. O método analítico apresentou para os três analitos de interesse, faixa ampla de linearidade (1,0 a 500,0 µg/mL; limites de quantificação de 1,0 µg/mL e coeficientes de variação intra e interensaio inferiores a 9,5%. Os limites de detecção estabelecidos foram 0,7 µg/mL, 0,8 µg/mL e 0,6 µg/mL, respectivamente para o MDMA, MDA e MDEA. O método foi seletivo na presença de epinefrina, cocaína, anfetamina, ácido acetilsalisílico, metanfetamina, ácido dietilbarbitúrico, p-aminobenzoil dietilbarbitúrico, paracetamol e cafeína.The abusive use of the amphetamine derivative ecsyasy in the world come increasing in the last years. Many tablets samples kept on the streets shown the presence not only of the MDMA- 3,4-methylenedioxymethamphetamine, the main drug component but also of the MDA - 3,4- methylenedioxyamphetamine and MDEA - 3,4-methylenedioxymethylethylamphetamine. The present study sought to develop and validate an analytical method for determination of MDMA, MDA and MDEA in tablets to be accessible for the most small or medium

  11. Farmacovigilância de drogas vegetais e seus derivados: uma ação necessária e já iniciada para a segurança do paciente, no contexto do uso racional de medicamentos | Pharmacovigilance of herbal drugs and their derivatives: the beginning of necessary action for patient safety in the context of rational use of drugs

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    Maria Aparecida Nicoletti

    2015-05-01

    Full Text Available Na antiguidade, o tratamento de enfermidades que acometiam os homens era essencialmente por meio de plantas medicinais. Com a revolução industrial no século XIX, essa alternativa de tratamento caiu em desuso. Nas últimas décadas, entretanto, voltou a ser empregada, devido a fatores como a dificuldade de acesso aos serviços médicos e farmacêuticos e o custo elevado dos medicamentos sintéticos. Consequentemente, o número de relatos de eventos adversos relacionados a drogas vegetais aumentou. Seu uso é comum na atenção primária à saúde e a maioria dos usuários acredita que seja seguro. A toxicidade das plantas medicinais ou de medicamentos que as contenham é um assunto de saúde pública, uma vez que podem desencadear desde reações adversas até intoxicações graves, além de poder interagir com fármacos convencionais. Existem poucos dados de segurança das drogas vegetais e, muito deles, não foram submetidos aos estudos de fase clínica. A monitoração dos efeitos indesejados por meio da implantação de um sistema de farmacovigilância que inclua as espécies vegetais medicinais se faz necessária. Contudo, no Brasil, a avaliação de segurança de drogas vegetais e seus derivados está no começo e, portanto, é necessário que ações sejam tomadas para que se estruture um sistema robusto e eficaz. -------------------------------------------------------------------------------------------- In antiquity, the treatment of diseases affecting humans was usually performed medicinal plants. Since the industrial revolution in the nineteenth century, this alternative treatment method has fallen into disuse. In recent decades, however, it has been used again because of factors such as lack of access to doctors and pharmacists and the high cost of synthetic drugs services. Consequently, the number of reports of adverse events related to plant drugs has increased. Its use is common in primary care, and most users believe that it is

  12. Estimation of evaporation in the Banabuiú dam, in the state of Ceará, Brazil, by different combined methods, derived from the Penman equation Estimativa da evaporação no açude Banabuiú, no estado do Ceará, por diferentes métodos combinados, derivados da equação de Penman

    Directory of Open Access Journals (Sweden)

    Raimundo A. de O. Leão

    2013-02-01

    aumento da evaporação, que se constitui em um dos principais componentes do balanço hídrico nos reservatórios, sobretudo em regiões áridas. Vários métodos de estimativa da evaporação foram propostos ao longo do tempo, muitos deles derivados da equação de Penman. Neste trabalho, foram avaliados seis diferentes métodos de estimativa da evaporação a fim de determinar qual o mais adequado para utilização em modelos hidrológicos para o balanço hídrico em reservatórios no Estado do Ceará. Os métodos avaliados foram os propostos por Penman, Kohler-Nordenson-Fox, Priestley-Taylor, deBruim-Keijman, Brutsaert-Stricker e deBruim, os quais apresentaram ótimo desempenho quando testados para o balanço hídrico durante a estação seca, sendo o de Priestley-Taylor o mais adequado, uma vez que os dados do balanço hídrico simulado com a componente evaporação estimada por este método foram os mais próximos dos dados do balanço hídrico observado a partir das medidas de nível do reservatório e da curva cota-volume fornecidos pela Companhia de Gestão dos Recursos Hídricos do Estado do Ceará - COGERH.

  13. 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 )

  14. Electrochemical studies for an acid fuel cell; Estudos eletroquimicos de uma celula a combustivel acida

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.R.; Avaca, L.A.; Ticianelli, E.A.; Ferreira, A.C.; Oliveira, J.C.T. de [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica

    1984-12-31

    This work describes the main steps for the development of the components of an one-kilowatt phosphoric acid H{sub 2}/O{sub 2} fuel cell stack. The electrochemical characteristics of fundamental components-electrodes and electrolyte-matrix have been evaluated in unitary fuel cell prototype by stationary polarization curves and continuous operation curves. The results confirmed the better efficiency of the hydrogen electrode and anticipated a very fair performance for the one-kilowatt stack. (author). 4 figs., 5 refs

  15. Individual internal monitoring of workers of Fabrica de Combustivel Nuclear - FCN

    International Nuclear Information System (INIS)

    Castro, Marcelo X.

    2005-01-01

    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)

  16. Electrochemical studies for an acid fuel cell; Estudos eletroquimicos de uma celula a combustivel acida

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E R; Avaca, L A; Ticianelli, E A; Ferreira, A C; Oliveira, J C.T. de [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica e Quimica

    1985-12-31

    This work describes the main steps for the development of the components of an one-kilowatt phosphoric acid H{sub 2}/O{sub 2} fuel cell stack. The electrochemical characteristics of fundamental components-electrodes and electrolyte-matrix have been evaluated in unitary fuel cell prototype by stationary polarization curves and continuous operation curves. The results confirmed the better efficiency of the hydrogen electrode and anticipated a very fair performance for the one-kilowatt stack. (author). 4 figs., 5 refs

  17. 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)

  18. Feasibility of biogas utilization in fuel cells; Viabilidade do uso de biogas em celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Sprenger, Humberto Elias [Programa de Pos-graduacao em Desenvolvimento de Tecnologia (PRODETEC/LACTEC/IEP), Cutitiba, PR (Brazil); Cantao, Mauricio Pereira [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], E-mail: mauricio.cantao@utp.br

    2010-10-15

    Waste water treatment stations using upflow anaerobic sludge blanket (UASB) produce biogas, composed of carbon dioxide diluted methane plus minority compounds. This kind of reactor is worthwhile but demands methane burning in order to reduce atmospheric pollution and damage to ozone layer. Meanwhile, biogas can be used for energy generation due to its heating value. In this paper a technical and economic feasibility study about the use of biogas as a hydrogen source for fuel cells feeding is presented. Two methods for assessment of biogas production in UASB reactor were compared for ETE Atuba Sul case. (author)

  19. 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.

  20. A case study of a sugar and alcohol plant: prospects for the production of alcohol and exceeding energy; Um estudo de caso de uma usina de acucar e alcool: perspectivas para a producao de alcool e energia excedente

    Energy Technology Data Exchange (ETDEWEB)

    Halmeman, Maria Cristina Rodrigues; Oliveira, Franciene Gois; Seraphim, Odivaldo Jose [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil)], E-mail: cristhalmeman@gmail.com; Halmenan, Radames Juliano [Universidade Tecnologica Federal do Parana (UTFPR), Campo Mourao, PR (Brazil); Michels, Roger Nabeyama [Instituto Federal de Santa Catarina (IFSC), Luzerna, SC (Brazil)

    2010-07-01

    Brazil stands out in the world scene as the largest producer and exporter of sugar and the main producer of ethanol derived from sugar cane, which generates the bagasse used to produce electrical energy for the plant as well as for electricity companies. Energy products from sugar cane, such as ethanol and bagasse have contributed significantly to reduce the gases that contribute to the greenhouse effect by replacing fossil fuels, that is, gasoline and diesel. The research is defined as exploratory and descriptive, the data were obtained in June, 2009 in a sugar cane and alcohol plant located in the state of Sao Paulo, Brazil. It was sought through direct interviews, to check what the prospects for the processing of sugar cane, alcohol production and generation of exceeding energy are. Therefore, the purpose of this study is to contextualize the current production of alcohol and electrical energy, with projections up to 2016. (author)

  1. Évaluation des politiques de lutte contre l'usage nocif de l'alcool en ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Le projet s'inscrit dans une étude menée dans plusieurs pays, l'International Alcohol Control Study (IAC). Il aura recours à une méthode longitudinale reposant sur des panels et tirera parti d'expériences réalisées dans les conditions naturelles, dans le cadre desquelles des modifications aux politiques seront apportées ...

  2. Politiques de lutte contre l'usage nocif de l'alcool et de réduction de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    West African Research and Training Hub on Environmental and Occupational Health in the Informal Economy. This project will help establish a West African Global Environmental and Occupational Health (GEO Health) Hub in environmental and occupational health. View moreWest African Research and Training Hub on ...

  3. Programa de prevencao do uso/abuso de alcool para adolescentes em contexto escolar: parar para pensar

    Directory of Open Access Journals (Sweden)

    Teresa Maria Mendes Diniz de Andrade Barroso

    2013-09-01

    Full Text Available OBJETIVO: Avaliar o efeito do programa Parar Para Pensar na prevenção do uso/abuso de bebidas alcoólicas de adolescentes em contexto escolar. MÉTODO: Realizou-se estudo quasi-experimental, com pré e pós-teste, com 178 participantes, estudantes no 7º ano escolar; o grupo experimental (n = 70 foi sujeito à intervenção durante um ano, e o grupo de controle (n = 108 não sofreu intervenção. Foram utilizados o Questionário de Conhecimentos Acerca do Álcool; Questionário de caracterização dos consumos; Escala de Expectativas Acerca do álcool e Escala de Aptidões Sociais. RESULTADOS: Constatou-se que os adolescentes submetidos ao programa apresentaram evolução positiva nas seguintes variáveis: frequência do consumo e ocorrência de episódios de embriaguez; e, ainda, melhorou os conhecimentos, as expectativas acerca do álcool e a percepção do consumo pelos pares (p < 05. CONCLUSÃO: O programa foi eficaz na estabilização do consumo, no aumento dos conhecimentos, na estabilização das expectativas positivas e na percepção do consumo pelos pares. Sugerem-se novos estudos e manutenção de follow-up para consolidar os resultados encontrados.

  4. Alcohol, biomass energy: technological and economical aspects of production; Alcool, energia da biomassa: aspectos tecnologicos e economicos da producao

    Energy Technology Data Exchange (ETDEWEB)

    Ometto, Joao Guilherme Sabino [Cooperativa dos Produtores de Acucar, Cana e Alcool do Estado de Sao Paulo Ltda. (COOPERSUCAR), Piracicaba, SP (Brazil)

    1993-12-31

    This paper presents some technological and economical aspects of sugar cane and alcohol production in Brazil since 1975 until nowadays. The evolution of their production is analysed and the relationship between cost-benefit and ethanol consumption is discussed 13 figs., 11 tabs.

  5. Alcohol, biomass energy: technological and economical aspects of production; Alcool, energia da biomassa: aspectos tecnologicos e economicos da producao

    Energy Technology Data Exchange (ETDEWEB)

    Ometto, Joao Guilherme Sabino [Cooperativa dos Produtores de Acucar, Cana e Alcool do Estado de Sao Paulo Ltda. (COOPERSUCAR), Piracicaba, SP (Brazil)

    1994-12-31

    This paper presents some technological and economical aspects of sugar cane and alcohol production in Brazil since 1975 until nowadays. The evolution of their production is analysed and the relationship between cost-benefit and ethanol consumption is discussed 13 figs., 11 tabs.

  6. ALCOol, vigiLAnce, Charge de travail : facteurs d'accident chez les jeunes conducteurs. Rapport final ALCOLAC

    OpenAIRE

    BERTHELON, Catherine; GALY, Edith; PAXION, Julie; FERRIER, Laurent

    2016-01-01

    D'après le modèle de courbe en U renversé d'Ansseau et Timsit-Berthier (1987 ; in Hadj-Mabrouk, 2001), le niveau de performance augmente avec celui de la vigilance jusqu'à un optimum, au-delà de cet optimum l'augmentation de la vigilance entraîne au contraire une baisse de la performance. L'excès de vigilance que représentent la tension (stress) ou l'hyperexcitation a un pouvoir de dégradation plus rapide sur les activités complexes que sur les activités les plus simples. Il y a donc un nivea...

  7. La publicité de la cigarette et de l'alcool dans la presse gratuite suisse d'information.

    OpenAIRE

    Olivier, J.

    2014-01-01

    Tobacco and alcohol are ordinary consumer goods that are still two overriding preventable causes of death in Switzerland. Massive advertising supports their selling and contributes to maintain a major public health problem up to date. The widely read free press represents an interesting advertising mean. The study of tobacco and alcohol advertisements published in the free newspaper 20 minutes through the year 2012 gives us a good idea of these products' advertising strategies. Compared to th...

  8. Évaluation des politiques de lutte contre l'usage nocif de l'alcool au ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Public Health Implications of Alcohol Industry Corporate Social Responsibility Programs (Latin America). Researchers are raising growing concerns over the impact of corporate social responsibility (CSR) programs in the alcohol industry. View morePublic Health Implications of Alcohol Industry Corporate Social ...

  9. Consumo de alcool e risco para doenca coronariana na regiao metropolitana de Sao Paulo: uma analise do Projeto GENACIS

    Directory of Open Access Journals (Sweden)

    Maria Cristina Pereira Lima

    2013-03-01

    Full Text Available OBJETIVOS: Examinar a associação entre consumo de álcool e risco para doença coronariana em amostra populacional. MÉTODOS: Estudo transversal, de base populacional, conduzido de janeiro/2006 a junho/2007, na região metropolitana de São Paulo, como parte do estudo internacional (Gender, Alcohol, and Culture: an International Study. Os sujeitos (1.501, sendo 609 homens e 892 mulheres eram residentes da região metropolitana de São Paulo, tinham 30 anos ou mais de idade e foram selecionados aleatoriamente, a partir de amostragem complexa por conglomerados. Todos os indivíduos consentiram em participar da pesquisa. A variável dependente foi risco cardíaco avaliado através do WHO Rose Angina Questionnaire. A análise multivariada consistiu em regressão logística, tendo sido realizado ajuste para uso de tabaco e índice de massa corpórea. RESULTADOS: A taxa de resposta foi 75%. Ser mulher, ter mais idade, ser negro, fumante e ter um índice de massa corpórea elevado, foram associados a maior risco para doença coronariana. Indivíduos que nunca beberam na vida (OR = 2,22 e ex-bebedores (OR = 2,42 tiveram maior risco de doença cardíaca do que aqueles que informaram beber até 19 g de álcool por dia, sem episódios de beber excessivo. Entre os que tiveram episódios de embriaguês observou-se uma tendência a maior risco (OR = 3,95, p = 0,09. CONCLUSÕES: Nossos achados sugerem um menor risco para doença coronariana entre os bebedores moderados. Destaca-se que os estudos que avaliam o impacto do álcool sobre doença cardíaca precisam identificar o padrão de uso de álcool dos sujeitos, visto que este aspecto pode modificar o risco. Políticas públicas são necessárias para reduzir o uso nocivo de álcool e a morbidade a ele relacionada no país.

  10. Politiques de lutte contre l'usage nocif de l'alcool et de réduction de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Crise du virus Ebola : Améliorer la communication scientifique et le journalisme local en période d'urgence et après une éclosion. La World Federation of Science Journalists (WFSJ) dirige un programme régional de communication et de formation pour les journalistes locaux, dans le but d'améliorer le journalisme.

  11. Consommation d’alcool et culture masculine dans l’Europe de l’époque moderne

    OpenAIRE

    Tlusty, B. Ann

    2018-01-01

    Pourquoi les gens buvaient-ils à l’époque moderne ? Mathias von Abele, un juriste allemand du xviie siècle, relève au moins quarante-cinq bonnes raisons de le faire, au nombre desquelles on peut citer l’amitié, l’honneur, la vertu, la bravoure, la virilité, les affaires et le commerce, sans oublier le plaisir de la dégustation et une agréable compagnie ; la rancœur et la mauvaise humeur, l’envie, la défiance, l’ennui et l’oisiveté sont également des motifs tout aussi impérieux. Le vocabulaire...

  12. Oxydation par l’oxygène moléculaire d’alcools en phase liquide en synthons carbonyles

    OpenAIRE

    Frassoldati , Antonio

    2011-01-01

    The selective alcohols oxidation to aldehydes, acids and ketones is an important transformation in chemistry. The use of molecular oxygen as oxidant is in adequation with a green chemistry perspective, since water is the only by-product. The oxidation of primary alcohols (1-octanol and geraniol) and secondary alcohols (2-octanol, 1-phenylethanol and pyridine substituted alcohols) has been studied in the presence of platinum supported carbon catalysts under air pressure in organic or mixed org...

  13. Isolamento e estudo experimental de duas novas culturas de bacilos ácido-alcool resistentes de muco nasal de leprosos

    Directory of Open Access Journals (Sweden)

    H. C. de Souza-Araujo

    1954-03-01

    Full Text Available The A. described on December 14, 1951, his first culture of acid-fast bacillus isolated from nasal mucus of a leprous girl. in this paper the A. describes two new strains of acid-fast bacilli gotten also from nasal mucus of other two leprous girls, L3 cases. The first patient (layse S had her mucus treated by petroff's method on December 16, 1952 and sown onto three tubes of loewenstein medium and in glycerin broth. After two weeks incubation at 37°C all three tubes of Loewenstein showed many punctiforme and pin-head yellowish colonies, whose microscopic examination proved to be of a pure acid-fast bacillus culture. This sample inoculated in rats and mice produced, after 55 days incubation, small tumors from which the culture was easily recovered. On April, 9, 1953 a new sample of nasal mucus of the same patient was sown in three tubes of Loewenstein. After two weeks incubation at 37°C all 3 tubes showed germination of small yellowish colonies of acid-fast bacilli. Within four months being gotten two samples of identical cultures in all smeared tubes of Loewenstein medium sown, proved that such cultures were not an ordinary ambient contamination. Second patient: - Maria N. After various sowing of different kinds of material from her, february 26, 1953 her nasal mucus treated by soda and sown onto Loewenstein medium, after 25 days incubation showed in only one tube, one small round colony, at first white, becoming creamy after three months. Transplants in various media grew at first slowly and after 2 or 3 generations grew faster. The "Layse" strain produced pellicle in glycerin broth and Dubos medium; the "Maria N." strain did not produce as yet. Both strains (Layse I and II, and Maria N. gave weak positive Dubos test in half-an-hour and negative after 24 hours reading. Both were strongly positive when stained by Gram, Ziehl-Neelsen and Fontes methods. Both strains gave also positive fluoroscopy. These cultures are being studied. The A. concludes that, according to his experience, the slower growing cultures of acid-fast bacilli isolated from leprosy material, are the more suitable for experimental work. Aknowledgement. The A. thanks to Miss MARIA DE LOURDES SANTANA for her valuable collaboration in the studies of the described cultures.

  14. Validation d'une méthode de quantification de l'alcoolémie chez les ...

    African Journals Online (AJOL)

    LOQ (0.146 g/L) was perfectly adapted to the needs of the Drink-Driving Law in Cote d'Ivoire (Statutory threshold ≤ 0.8 g/L). Blood Alcohol Concentrations in drivers who have drunk was on average 2.4 times the statutory threshold in Cote d'Ivoire. Conclusion: The application of our analytical method to the study of trauma ...

  15. Distribución espacial de anomalías del NDVI derivado del sensor VEGETATION SPOT 4/5 ysu relación con las coberturas vegetales, usos de la tierra y características geomorfológicas en la provincia de Santiago del Estero, Argentina / Spatial distribution of anomalies of NDVI derived from sensor VEGETATION SPOT 4/5 and its relation with vegetation cover, uses of ground and geomorphology in Santiago del Estero, Argentina

    Directory of Open Access Journals (Sweden)

    Jose Luis Tiedermann

    2010-12-01

    Full Text Available Se determinaron las anomalías negativas (AN y positivas (AP del NDVI derivado del sensor VEGETATION SPOT 4/5, en la provincia de Santiago del Estero, Argentina. El periodo analizado (1998-2008 tuvo fuertes variaciones en los patrones de precipitación, por efecto del ENSO, por cuanto las anomalías del NDVI fueron evaluadas, mediante tabulación cruzada, en función de dos periodos: húmedo (PH y seco (PS. Las AN, se relacionaron, durante todo el periodo, con vegetación halófila en áreas deprimidas salobres, con vegetación hidrófila en ambientes acuáticos y con suelo rocoso. Durante el PS, las AN se relacionaron con áreas deforestadas con fines agrícolas. Las AP, se relacionaron, durante todo el periodo, con el bosque Chaqueño denso y bosque Chaqueño Serrano denso. La mayor estabilidad y productividad de biomasa verde de los bosques, estaría relacionada, a su mayor biodiversidad, estratificación, al predominio de especies leñosas perennes de raíces profundas y a las estratégicas adaptaciones, morfológicas y fisiológicas, para el uso eficiente del agua. Las regiones geomorfológicas no se relacionan entre si entre periodos.AbstractThe negative (AN and positive (AP anomalies of the NDVI derived from sensor VEGETATION SPOT 4/5 were determined in the province of Santiago del Estero, Argentina. The analyzed period (1998-2008 presented strong variations in rainfall patterns, as a result of the ENSO, inasmuch as the anomalies of the NDVI were evaluated, by means of crossed tabulation, based on two periods: humid (PH and dry (PS. The AN, were related with halophytic species of depressed areas, with vegetation aquatic hydrophilic and rocky ground. During the dry period, the AN were related to deforested areas with agricultural aims. The AP, were related, throughout the period with the forest dense Chaco Semiarid and forest dense Chaco Serrano. The greater stability and productivity of green biomass of forest, would be related, greater

  16. Substituição do milho e do feno de capim-tifton por palma forrageira. Produção de proteína microbiana e excreção de uréia e de derivados de purina em vacas lactantes Effects of replacing of corn and Tifton hay with forage cactus on microbial protein synthesis and nitrogen metabolism in lactating dairy cows

    Directory of Open Access Journals (Sweden)

    Veronaldo Souza de Oliveira

    2007-08-01

    Full Text Available O experimento foi conduzido com os objetivos de estimar a produção e a eficiência de síntese de proteína microbiana utilizando-se a excreção total de derivados de purinas (DP e avaliar as concentrações de uréia na urina, de uréia e N-uréia no plasma e no leite de vacas holandesas em lactação alimentadas com dietas formuladas com diferentes níveis (0; 12,0; 25,0; 38,0 e 51,0% de palma forrageira (Opuntia ficus indica Mill em substituição total ao milho (Zea mays L. e parcial ao feno de capim-tifton (Cynodon spp. Foram utilizadas cinco vacas holandesas distribuídas em um quadrado latino 5 x 5. Cada período experimental teve duração de 17 dias, dez para adaptação dos animais à dieta e sete para coleta de dados. O volume urinário foi estimado em amostras spot de urina obtidas 4 horas após a alimentação. O volume urinário (27,62 L, a excreção urinária de ácido úrico (35,78 mmol/dia, alantoína na urina (288,42 mmol/dia, alantoína no leite (18,11 mmol/dia e alantoína total (306,54 mmol/dia, a excreção de derivados de purina total (342,33 mmol/dia e de purinas absorvidas (350,03 mmol/dia, a síntese de proteína microbiana (1.376,07g/dia e a eficiência da síntese de proteína microbiana (115,38 g/kgNDTconsumido não foram afetados pela substituição do milho e do feno de tifton por palma na dieta. A excreção de uréia na urina (mg/kg PV e as concentrações de uréia e N-uréia no plasma (mg/dL decresceram de forma linear, enquanto a excreção e as concentrações de uréia e N-uréia no leite e de glicose plasmática não foram influenciadas pelos níveis de palma na dieta. O milho pode ser substituído integralmente e o feno, parcialmente, por palma forrageira em dietas para vacas holandesas em lactação, pois a substituição não afetou a produção de proteína microbiana ou as perdas do nitrogênio dietético pela excreção de uréia.The objective of this trial was to evaluate the effect of replacing

  17. Efeito do período de coleta de urina, dos níveis de concentrado e de fontes protéicas sobre a excreção de creatinina, de uréia e de derivados de purina e a produção microbiana em bovinos Nelore Effect of urinary collection days, concentrate levels and protein sources on creatinine, urea and purine derivatives excretions and microbial protein synthesis in Nellore cattle

    Directory of Open Access Journals (Sweden)

    Analívia Martins Barbosa

    2006-06-01

    Full Text Available O efeito do período de coleta de urina sobre a excreção urinária de creatinina, uréia e derivados de purinas (DP, as purinas absorvidas e a produção de compostos nitrogenados microbianos (Nmic foi avaliado em bovinos Nelore de quatro categorias: novilhas, machos castrados, machos não-castrados e vacas em lactação. A produção de Nmic obtida em amostras spot de urina foi comparada àquela obtida via coleta total. Dezesseis animais da raça Nelore mantidos em confinamento foram distribuídos em delineamento inteiramente casualizado em esquema de parcelas subdivididas, tendo nas parcelas os tratamentos em esquema fatorial 2 x 4 (dois níveis de concentrado, 25 ou 50%, e quatro categorias de bovinos, novilhas, machos castrados, machos não-castrados e vacas em lactação e nas subparcelas os seis dias de coleta. Não houve interação entre níveis de concentrado, categorias de animal e dias de coleta para as variáveis avaliadas. O volume urinário não foi influenciado pelos níveis de concentrado e os dias de coleta, contudo, foi significativamente maior para as vacas. A excreção de creatinina não foi afetada pelos tratamentos e dias de coletas, observando-se média de 27,1 mg/kg0,75. As purinas absorvidas e a produção de Nmic também não foram influenciadas pelos tratamentos e os dias de coleta. A produção de Nmic, estimada pela amostra spot de urina, não diferiu daquela obtida pela coleta total, nem entre os níveis de concentrado ou entre as categorias de animal. Concluiu-se que o período de coleta de urina de 24 horas é suficiente para experimentos utilizando animais Nelore, independentemente de serem novilhas, machos castrados ou não-castrados ou vacas, e que a coleta de amostra spot de urina também pode ser usada para estimar a produção de Nmic.The effects of collection days on urinary excretion of creatinine and purine derivatives (PD, absorbed purines and microbial N synthesis (Nmic were evaluated in different

  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); 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. 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)

  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. 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)

  2. 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)

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. 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

    1993-12-31

    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.

  9. 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)

  10. 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.

  11. SÍNTESIS DE OXITOCINA EN FASE SÓLIDA USANDO DERIVADOS DE TERBUTOXICARBONILO Y FLUORENILMETOXICARBONILO

    Directory of Open Access Journals (Sweden)

    Julio C Calvo

    2010-08-01

    Full Text Available La oxitocina, péptido cíclico cuya secuencia es CYIQNCPLG, fué el primer péptido de importancia biológica que pudo ser sintetizado. En este trabajo se compara la síntesis de la oxitocina usando resina p metilbenzhidrilamina (MBHA para la síntesis por estrategia t-Boc y resina Rink p-metilbenzhidrilamina (Rink MBHA para la síntesis por estrategia Fmoc, con altos rendimientos. El péptido crudo se ciclizó en una disolución acuosa de dimetilsulfóxido al 10%. La caracterización se llevó a cabo por espectrometría de masas y resonancia magnética nuclear, y se logró detectar la presencia de dos isómeros.

  12. RIESGOS PARA LA SALUD DERIVADOS DEL CONSUMO VOLUNTARIO E INVOLUNTARIO DE TABACO

    Directory of Open Access Journals (Sweden)

    Finn Edler von Eyben

    2003-01-01

    Full Text Available Este trabajo examina y actualiza los aspectos sanitarios del consumo de tabaco basándose especialmente en estudios llevados a cabo en países europeos, con énfasis en el tabaquismo en el lugar de trabajo. Se revisan los riesgos del consumo de tabaco para la salud en ambos sexos, el impacto en la esperanza de vida, las ventajas del abandono del consumo de tabaco, el patrón social del tabaquismo en las sociedades occidentales y las diferencias sociales en las enfermedades que causa. Se describen también los efectos inmediatos y a largo plazo del consumo involuntario de tabaco, sus consecuencias en el lugar de trabajo, y las técnicas de medida del Aire Contaminado por Humo de Tabaco (ACHT.

  13. Plan de manejo ambiental planta distribuidora de combustibles líquidos derivados de los hidrocarburos

    OpenAIRE

    Gómez De La Torre Kusianovich, Raúl Tomás; Gómez De La Torre Kusianovich, Raúl Tomás

    2014-01-01

    Bachiller en Ingeniería Industrial graduado en la Universidad Nacional de Ingeniería, especializado en el área Producción Industrial en la fábrica de cubiertos, herramientas y autopartes INOXA SA con dos plantas industriales. Importante experiencia en Plantas de Ventas y Operaciones Comerciales en compañías del rubro de Hidrocarburos como Emcopesac, Petróleos del Perú, Mobil Oil del Perú, Multicamps y otras. Importante experiencia en Marketing y Ventas de combustibles y lubricantes. Amplia...

  14. Derivados del Nylon 3 con grupos laterales alcoxicarbonilos ramificados y cíclicos

    OpenAIRE

    García Álvarez, Montserrat

    1997-01-01

    El presente trabajo se ha centrado en la síntesis, caracterización y estudio estructural de poli(alfa-alquil-beta-L-aspartato)s con grupos laterales ramificados y cíclicos. Se han sintetizado los monómero: (S)-4-alcoxicarbonil-2-azetidinonas cuya síntesis se basa en la transesterificación de la beta-lactama del éster bencílico del ácido L-aspártico con el correspondiente alcohol. Se han establecido las condiciones óptimas de la polimerización aniónica por apertura del anillo de lactama, hacie...

  15. Obtención de hidrogeles derivados del ácido itacónico

    Directory of Open Access Journals (Sweden)

    Francisco J. Sánchez

    1996-01-01

    Full Text Available Se presenta una técnica para la obtención de hidrogeles de acrilamida, empleando comonámeros monoésteres del ácido itacántco. A estos hidrogeles se les determina su cinética de hinchamiento a pH neutro y 20°C.

  16. APOIO À DECISÃO DE COMPRA NA INDÚSTRIA DE CIMENTOS E DERIVADOS

    OpenAIRE

    Renan Felinto de Farias Aires; Leonardo Gevezier Braga; Jose Camelo Silveira Neto; Afrânio Galdino de Araújo

    2017-01-01

    O setor da construção civil é um dos mais dinâmicos setores da economia brasileira, impactando toda a complexa cadeia de atividades ligadas à construção, como, por exemplo, a produção de cimento. Assim, todas as indústrias ligadas à produção desse material necessitam tomar decisões da melhor maneira de forma a competirem no acirrado mercado brasileiro de cimento - quarto maior produtor do mundo. Por conta disso, o objetivo deste estudo é desenvolver um modelo multicritério para apoiar a compr...

  17. Protección inducida por nanococleatos derivados de proteoliposomas de Leptospira interrogans serovar Canicola

    Directory of Open Access Journals (Sweden)

    Beatriz Tamargo

    2012-04-01

    Full Text Available Desde los años 20 del pasado siglo, hasta el presente, en el mundo se han desarrollado y empleado vacunas de células enteras contra la leptospirosis que confieren una corta inmunidad; la mayoría no adyuvadas y dirigidas, fundamentalmente, contra los diferentes serogrupos de la especie Leptospira interrogans, contenidos en las preparaciones. Numerosos han sido los intentos realizados para lograr una formulación vacunal más pura, efectiva, de amplio espectro y duración de la protección que las bacterinas de células enteras inactivadas. Sin embargo, hasta el momento no se ha registrado ninguna vacuna con tales características. En el presente trabajo se obtuvieron antígenos de membrana externa a partir de una cepa cubana autóctona (Cepa 87, L. interrogans serovar Canicola, mediante una modificación de la tecnología para la producción de vesículas de membrana, patentada por investigadores del Instituto Finlay. Estos antígenos con estructura nanoproteoliposómica fueron formulados/adyuvados mediante diferentes estrategias, logrando cinco preparaciones con estructura coclear, que constituyen nanopartículas de aproximadamente 100 a 150 nm de largo y entre 15 a 30 nm de diámetro. Los inmunógenos se inocularon en el biomodelo Mesocrisetus aureatus, con dos dosis e intervalo de seis semanas. El reto fue realizado con 100.000 DL 50 . Los resultados demuestran que las nuevas formulaciones vacunales confieren protección frente al reto homólogo y fueron capaces de eliminar el estado de portador, lo que unido a la robustez del método de preparación, el mayor nivel de pureza, en comparación con las bacterinas, y la no necesidad del hidróxido de aluminio, las convierten en una alternativa de interés para continuar su desarrollo.

  18. Riesgos para la salud derivados del consumo voluntario e involuntario de tabaco

    Directory of Open Access Journals (Sweden)

    Eyben Finn Edler von

    2003-01-01

    Full Text Available Este trabajo examina y actualiza los aspectos sanitarios del consumo de tabaco basándose especialmente en estudios llevados a cabo en países europeos, con énfasis en el tabaquismo en el lugar de trabajo. Se revisan los riesgos del consumo de tabaco para la salud en ambos sexos, el impacto en la esperanza de vida, las ventajas del abandono del consumo de tabaco, el patrón social del tabaquismo en las sociedades occidentales y las diferencias sociales en las enfermedades que causa. Se describen también los efectos inmediatos y a largo plazo del consumo involuntario de tabaco, sus consecuencias en el lugar de trabajo, y las técnicas de medida del Aire Contaminado por Humo de Tabaco (ACHT.

  19. APROXIMACIÓN A LOS FACTORES DE MEJORA DE LA EFICACIA ESCOLAR DERIVADOS DEL PROGRAMA IQEA

    Directory of Open Access Journals (Sweden)

    Isabel López Cobo

    2011-01-01

    Full Text Available Este trabajo muestra los resultados obtenidos en un estudio realizado con maestros y maestras de Educación Infantil y Primaria de la ciudad de Córdoba acerca de la valoración de los elementos intervinientes en la mejora de la eficacia escolar, agrupados en factores como centro educativo, dirección del centro, profesorado, enseñanza-aprendizaje, opinión del alumnado y entorno familiar y escolar. Asimismo, se ha valorado la idoneidad de incorporar en sus centros de trabajo los parámetros marcados por el programa de mejora de la eficacia escolar IQEA. En un segundo momento, se ha recogido la opinión del alumnado de tercero de las diferentes especialidades de Educación Primaria de la Universidad de Córdoba, acerca de los factores que influyen en la mejora de la eficacia escolar y en la oportunidad que ofrece el programa IQEA para la consecución de la misma.

  20. Dosificación y validación de aspirina (ASA y derivados en orina

    Directory of Open Access Journals (Sweden)

    Francisco Martínez Cruz

    1996-12-01

    Full Text Available Se estudiaron 131 casos de niños con diferentes edades, sexo y raza, aparentemente sanos, procedentes de los servicios de consulta externa del Hospital Pediátrico Docente "Juan Manuel Márquez", con el fin de conocer concentraciones basales de salicilatos en orina. Posteriormente se estudiaron 20 casos voluntarios con el objetivo de establecer valores de referencia y por último se procesaron 10 casos de niños con intoxicación por salicilato con el propósito de conocer rango tóxico de este parámetro en orina.131 cases of children of different ages, sex, and race, apparently sound, coming from the outpatient department of the "Juan Manuel Márquez" Pediatric Teaching Hospital, were studied aimed at knowing basal concentrations of salicylates in urine. 20 voluntary cases were studied later to establish reference values, and lo cases of children with intoxication due to salicylate were processed so as to determine the toxic range of this parameter in urine.

  1. Competencia informacional y brecha digital: preguntas y problemas emergentes derivados de investigación

    Directory of Open Access Journals (Sweden)

    Gloria Patricia Marciales Vivas

    2012-04-01

    Full Text Available El artículo presenta resultados del estudio sobre el análisis de los cambios en las competencias informacionales vinculadas con el tránsito del formato impreso al digital en contextos universitarios. En el estudio fenomenográfico se analizan las trayectorias familiares y escolares y su relación con las prácticas de uso de fuentes de información en los dos formatos. Los resultados dan cuenta de las narraciones construidas por los jóvenes en sus historias familiares y escolares sobre las formas de acceder, evaluar y usar fuentes de información en contextos académicos.

  2. Perspectives for the brazilian petroleum market; Perspectivas do mercado de derivados no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Borschiver, Suzana [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica. Sistema de Informacao da Industria Quimica (SIQUIM); Barros, Marisa M. [Refinaria de Petroleos de Manguinhos, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The present work aims to present an overview of the Brazilian petroleum derivatives market following the loosening of PETROBRAS's monopoly in 1997, and to highlight the redefining of the roles of the traditional actors in this sector - refineries and petrochemical complexes - as well those of the new players - the formulators and importers. Regulation of this new model following the opening of the market has been important in establishing a competitive environment, while the competitive strategies adopted by companies have undoubtedly been fundamental to their survival. Along with these changes, this work also considers other aspects of the market, such as: the insufficiency of domestic production to meet the growing demand for derivatives, mainly LPG, naphtha and diesel, making Brazil more dependent on imports; and the technological and capacity limitations of the refinery sector, which create an impediment to the processing of the country's domestic, typically heavy crude, oil production, the offer of which is currently increasing, while excess production is destined for export. While the overall effect of a scenario favorable to internationalization is to make companies more vulnerable to the global politico-economic conjuncture, it also opens the possibility for them to access new technologies and markets, which is crucial for their development and increased competitiveness. This article presents examples of alternatives encountered by the refining sector in its efforts to meet market necessities. (author)

  3. Respuesta inmune mucosal inducida por proteoliposoma y cocleato derivados de N. meningitidis serogrupo B

    Directory of Open Access Journals (Sweden)

    Judith del Campo

    2009-08-01

    Full Text Available Mucosal vaccination offers attractive advantages to conventional systemic vaccination. Most pathogens enter or establish infection at mucosal surfaces. This represents an enormous challenge for vaccine development. Nevertheless, the availability of safe and effective adjuvants that function mucosally is the major limitation. Therefore, we investigated the impact of mucosal immunization with the Neisseria meningitidis B proteoliposome (AFPL1, Adjuvant Finlay Proteoliposome 1 and its-derived cochleate (Co, AFCo1. They contain multiple PAMPs as immunopotentiators and have delivery system ability as well as Th1 polarization activity. Groups of female mice were immunized by nasal, oral, intravaginal, or intramuscular routes with three doses with AFPL1/AFCo1 alone or containing ovalbumin or glycoprotein (g D2 from Herpes Simplex Virus type 2 (HSV-2. High levels of specific IgG antibodies were detected in sera of mice vaccinated with either route. However, specific IgA antibodies were produced in saliva and vaginal wash only following mucosal delivering. The polarization to a Th1 pattern was confirmed by testing the induction of IgG2a/IgG2c antibody, positive delayed-type hypersensitivity reactions, and gIFN production. Additionally, AFCo1gD2 showed practically no vaginal HSV-2 replication and 100% protection against lethal vaginal HSV-2 challenge. In conclusion, the results support the use of AFCo1 as potent Th1 adjuvant for mucosal vaccines, particularly for nasal route.

  4. Development of chitosan derivatives with anhydride maleic; Desenvolvimento de derivados de quitosana com anidrido maleico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da, E-mail: solbiologa@hotmail.com [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

    2015-07-01

    Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

  5. Rol de la Prostaciclina y sus derivados en el tratamiento de la hipertension arterial pulmonar

    Directory of Open Access Journals (Sweden)

    j. O. Caneva

    2003-06-01

    Full Text Available La hipertensión arterial pulmonar (HTP es definida como un grupo de enfermedades caracterizadas por un aumento progresivo de la resistencia vascular pulmonar que conduce a fallo ventricular derecho y muerte. Se ha demostrado en pacientes con HTP y en modelos experimentales una desregulación en la vía metabólica de la prostaciclina. Recientemente, la terapia continua endovenosa con prostaciclina (epoprostenol ha demostrado mejorar los síntomas y el pronóstico en los pacientes con clase funcional III y IV de la New York Heart Association (NYHA, con diferentes tipos de HTP. Sin embargo, la administración de epoprostenol requiere métodos invasivos con un catéter endovenoso permanente y está asociado a varios efectos colaterales y potencialmente a complicaciones serias. Se están considerando en la actualidad otros tratamientos con prostaciclina, utilizando análogos estables de la misma administrados por inhalación (iloprost, en forma subcutánea (treprostinil o por vía oral (beraprost. En los últimos años, diferentes estudios internacionales, multicéntricos, doble ciego, han demostrado la eficacia de esos análogos estables en HTP comparados con la terapia convencional, prometiendo un futuro mejor para estos pacientes.Pulmonary arterial hypertension (PAH is defined as a group of diseases characterised by a progressive increase of pulmonary vascular resistance leading to right ventricular failure and death. A dysregulation of prostacyclin metabolic pathways has been demonstrated in patients with PAH and in experimental models. Recently, therapy with continuous intravenous prostacyclin (epoprostenol has been shown to improve symptoms and prognosis in New York Heart Association (NYHA functional class III and IV patients with different types of PAH. However, epoprostenol administration requires invasive methods with a permanent intravenous catheter and is associated with several side effects and potentially serious complications. Other modes of prostacyclin therapies are being considered using stable prostacyclin analogues administered by inhalation (iloprost, subcutaneously (treprostinil or orally (beraprost. Over the last years, different multicenter international double-blind trials have demonstrated the efficacy of those novel prostacyclin analogues in PAH compared to conventional therapy promising a better future for these patients.

  6. Ejecución de créditos derivados de contratos bancarios

    OpenAIRE

    Gómez de Liaño Diego, Rosa

    1998-01-01

    El tráfico mercantil y su desarrollo ha dado lugar a la implantación de relaciones y situaciones contractuales que se han abierto paso muy deprisa, y forman parte de nuestro entorno y dentro de esa corriente los contratos bancarios, que tienen como objeto principal la concesión de crédito , han adquirido una dimensión principal, adoptando formas y peculiaridades derivadas de las exigencias de cada momento.

  7. Derivados de aminociclitoles, procedimiento de obtención y usos

    OpenAIRE

    Díaz Bueno, Lucía; Casas Brugulat, Josefina; Bujons Vilàs, Jordi; Egido Gabás, Meritxell; Delgado Cirilo, Antonio; Llebaria, Amadeu

    2009-01-01

    La presente invención se refiere a los compuestos de fórmula general (1) ya sus usos como composiciones farmacéuticas para el tratamiento de enfermedades relacionadas con la acumulación lisosomal de esfingolípidos, tales como la enfermedad de Gaucher, la enfermedad de TaySachs, la enfermedad de Sandhoff, la enfermedad de Fabry, la enfermedad de Niemann-Pick, leucodistrofia metacromática y la enfermedad de Krabbe. Además, la invención se refiere al procedimiento de obte...

  8. Determination of the specific heat petroleum derivates; Determinacao do calor especifico de derivados ultrapesados de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros Hernandez, Julie A.; Zuniga Linan, Lamia; Jardini, Andre; Maciel, Maria Regina Wolf; Maciel Filho, Rubens Maciel [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Quimica; Medina, Lilian Carmen [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil fractions in the range from 80 deg to 350 deg C . Through the study of this variation, the equation nowadays used can be adjusted, in order to determine the specific heat. New values of the constants are determined, so that the equation can be used for these complex products, optimizing the estimative of Cp and so no experimental data are always necessary for simulations. (author)

  9. Reología de derivados de la yema de huevo deshidratada

    Directory of Open Access Journals (Sweden)

    Partal, Pedro

    2000-08-01

    Full Text Available The emulsification process, as weIl as and the emulsion rheology and stability, greatly depends on the rheological properties of the continuous phase, the most important ingredient of which is yolk. However, since native yolk is not microbiologically stable, processing of yolk, such as spray-drying, is necessary for food applications. The influence of processing by spray-drying on the microstructure and rheological properties of yolk was investigated using oscillatory, creep and steady state flow measurements. The spray-drying process produces denaturation of proteins giving rise to a dramatic change from a fluid-like behaviour, as corresponds to the native yolk, to a gel-like behaviour corresponding to the reconstituted dried yolk (45% solids. Temperature exerts a slight influence on the linear viscoelastic properties of processed yolk.Tanto el proceso de emulsificación como las propiedades reológicas y la estabilidad de una emulsión alimentaria, tipo mayonesa, dependen en gran medida de la microestructura y la reología de la fase continua acuosa, cuyo ingrediente principal es la yema de huevo. Debido a la inestabilidad microbiológica de ésta se hacen necesarios procesos de deshidratación por atomización para conservarla con fines alimentarios. En este trabajo se trata de determinar la influencia que ejerce la deshidratación sobre la microestructura analizando las propiedades reológicas de la yema mediante ensayos reológicos de cizalla oscilatoria, de flujo en estado estacionario y de fluencia viscosa. Se llegó a la conclusión de que la deshidratación produce la desnaturalización de las proteínas provocando un cambio desde un comportamiento tipo fluido (yema nativa a un comportamiento tipo gel (yema deshidratada reconstituida al 45% en sólidos. Por otro lado, se ha observado una escasa variación de las propiedades viscoelásticas lineales de la yema deshidratada con la temperatura.

  10. La profilaxis de las infecciones puerperales por los derivados de la sulfanilamida

    Directory of Open Access Journals (Sweden)

    Hernando Acosta S.

    1940-04-01

    ha sido siempre un tema de actualidad. La obstetricia moderna ha llegado a resolver multitud de problemas terapéuticos que constituían un verdadero rompecabezas para los parteros de épocas relativamente recientes. Con todo, hoy persisten, sin solución satisfactoria, problemas de tan vital importancia como el de las gestosis y el de las formas graves de infección puerperal, contra las cuales vemos fracasar día por día, la mayor parte de las medidas tera péuticas aconsejadas. Quizá esto mismo ha servido de base para orientar las modernas investigaciones por un rumbo más lógico.

  11. Oil product blending optimization system; Sistema de otimizacao de misturas de derivados

    Energy Technology Data Exchange (ETDEWEB)

    Costa, F.L.P.; Sousa, L.C.F.; Joly, M.; Takahashi, M.T.; Magalhaes, M.V.O.; Mendonca, P.N. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The current scenario of the world refining industry demands significant investment in the improvement of its products and production processes quality, either due to a competitive market or strict environmental restrictions, requiring deep changes in the oil companies. In this environment, blending optimization has been receiving increasing attention in both academic and industrial sectors resulting in the development and improvement of tools for decision support and realtime control. The main objective of these tools is to optimize, according to either an economic or an operational criterion, the fuel blending recipe, guaranteeing the product specification with minimum giveaway in the critical properties and avoiding the reblending process. This work presents a blending optimization system of oil products named OTIMIST and instances of its application in PETROBRAS' Recap refinery. (author)

  12. COMPETENCIA INFORMACIONAL Y BRECHA DIGITAL: PREGUNTAS Y PROBLEMAS EMERGENTES DERIVADOS DE INVESTIGACIÓN

    Directory of Open Access Journals (Sweden)

    Gloria Patricia Marciales Vivas

    2012-01-01

    Full Text Available El artículo presenta resultados del estudio sobre el análisis de los cambios en las competencias informacionales vinculadas con el tránsito del formato impreso al digital en contextos universitarios. En el estudio fenomenográfico se analizan las trayectorias familiares y escolares y su relación con las prácticas de uso de fuentes de información en los dos formatos. Los resultados dan cuenta de las narraciones construidas por los jóvenes en sus historias familiares y escolares sobre las formas de acceder, evaluar y usar fuentes de información en contextos académicos.

  13. Functional properties of extruded nano composites based on cassava starch, polyvinyl alcohol and montmorillonite; Propriedades funcionais de nanocompositos extrusados de amido de mandioca, alcool polivinilico e montmorilonita

    Energy Technology Data Exchange (ETDEWEB)

    Debiagi, Flavia; Mali, Suzana [Departamento de Bioquimica e Biotecnologia, Universidade Estadual de Londrina, PR (Brazil)

    2011-07-01

    The objectives of this work were to produce expanded nano composites (foams) based on starch, PVA and sodium montmorillonite and characterize them according to their expansion index (EI), density, water absorption capacity (WSC), mechanical properties and X-ray diffraction. The nano composites were prepared in a single-screw extruder using different starch contents (97.6 - 55.2 g/100 g formulation), PVA (0 - 40 g/100 g formulation), unmodified nano clay - Closite - Na (0 - 4. 8 g/100 g formulation) and glycerol (20 g/100 g formulation) as plasticizer. The addition of montmorillonite and PVA resulted in an increase of EI and a decrease of density of the samples, and reduced WSC and increased the mechanical strength of the foams. Through the analysis of X-ray diffraction can be observed that the addition of montmorillonite led to production of intercalated nano composites in all samples. (author)

  14. Alcohol, energy of the biomass: technological and economical aspects of the production; Alcool, energia da biomassa: aspectos tecnologicos e economicos da producao

    Energy Technology Data Exchange (ETDEWEB)

    Ometto, Joao Guilherme Sabino [Cooperativa de Produtores de Cana, Acucar e Alcool do Estado de Sao Paulo Ltda. (COPERSUCAR), Sao Paulo, SP (Brazil)

    1993-05-01

    This text synthesizes a presentation made by president of COPERSUCAR, Cooperative of Producing of Cane, Sugar and Alcohol of Sao Paulo's State Ltd., private organization, in the Escola de Engenharia de Sao Carlos (University of Sao Paulo). It is shown the role of COPERSUCAR in the technological development of the industry of the sugar cane and alcohol. It is also presented the technological advanced and economic aspects of this industry. Among the main presented aspects they stand out: evolution of the production of the cane, sugar and alcohol; prices and costs of production of the alcohol; potential of reduction of industrial costs; biodegradable plastic and reduction of the tax of emission of CO{sub 2} in the atmosphere.

  15. Nitroxydes chiraux à squelette imidazolidin-4-one comme catalyseurs d'oxydation énantiosélective d'alcools par O2

    OpenAIRE

    Carbo Lopez , Marta

    2014-01-01

    The aim of this thesis was to evaluate the use of chiral nitroxides containing an imidazolidin-4-one squeletton as enantioselective catalysts for the aerobic oxidation of alcohols. In this view, several nitroxides with different α substituents have been synthesized to investigate the influence of these groups. Several co-catalysts reported in the literature have been tested for the oxidation reactions that take place at room temperature and atmospheric pressure. These catalytic systems can be...

  16. Replacement of diesel oil by hydrous ethyl alcohol in direct burning: a comparison; Substituicao do oleo diesel por alcool etilico hidratado na queima direta: uma comparacao

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Edgar Paz; Carvalho Junior, Joao Andrade de; Carrocci, Luiz Roberto [Universidade Estadual Paulista (FEG/UNESP), Guaratingueta, SP (Brazil). Fac. de Engenharia], Emails: edgarpaz@feg.unesp.br, joao@feg.unesp.br, carrocci@feg.unesp.br

    2006-07-01

    This article presents a study of the substitution of diesel fuel by ethyl alcohol in direct burning. The investigation is concentrated in the physical-chemical properties of the fuels, the combustion thermodynamics, the atomization, and the pollutants formation. Results show that hydrated ethyl alcohol can be an attractive alternative for diesel fuel, mainly by the benefits in the combustion process and the pollutants formation. Nevertheless, care must be taken in the substitution to prevent losses by evaporation, fire risks and material damage by corrosion. (author)

  17. Alcohol, energy of the biomass: technological and economical aspects of the production; Alcool, energia da biomassa: aspectos tecnologicos e economicos da producao

    Energy Technology Data Exchange (ETDEWEB)

    Ometto, Joao Guilherme Sabino [Cooperativa de Produtores de Cana, Acucar e Alcool do Estado de Sao Paulo Ltda. (COPERSUCAR), Sao Paulo, SP (Brazil)

    1993-05-01

    This text synthesizes a presentation made by president of COPERSUCAR, Cooperative of Producing of Cane, Sugar and Alcohol of Sao Paulo's State Ltd., private organization, in the Escola de Engenharia de Sao Carlos (University of Sao Paulo). It is shown the role of COPERSUCAR in the technological development of the industry of the sugar cane and alcohol. It is also presented the technological advanced and economic aspects of this industry. Among the main presented aspects they stand out: evolution of the production of the cane, sugar and alcohol; prices and costs of production of the alcohol; potential of reduction of industrial costs; biodegradable plastic and reduction of the tax of emission of CO{sub 2} in the atmosphere.

  18. Vers la synthèse totale de la macrolactine A. Nouvelles substitutions d'alcools propargyliques catalysées par de l'or(III).

    OpenAIRE

    Georgy , Marie

    2006-01-01

    The first part of this thesis describes a synthetical approach of antimicrobial agent Macrolactin A. This approaoch is based on two original stratégies to build the conjugated systems: one is the isomerisation of a propagylic ketone and the other is a two reaction sequence, namely a Johnson-Claisen reaction followed by an alumina- promoted isomerisation. The stereogenic centres were built by catalytic asymmetric reactions. The second part of the manuscript describes a new nucleophilic substit...

  19. Modelling and numerical simulation of the gasoline containing alcohol spilling in the groundwaters; Modelagem e simulacao numerica do derramamento de gasolina acrescida de alcool em aguas subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Cordazzo, Jonas; Maliska, Clovis R. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica]. E-mails: jonas@sinmec.ufsc.br; maliska@sinmec.ufsc.br; Corseuil, Henry X. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Sanitaria e Ambiental]. E-mail: corseuil@ens.ufsc.br

    2000-07-01

    This work presents a model and the respective two-dimensional numerical solution for the problem of pollutant spilling on the soil saturated region,in finite volumes, with first order biodegradation model. The model is adapted to the brazilian gasoline considering the ethanol influence on the biodegradation of the BTEX constituents and on the ethanol co-solvence in the gasoline phenomenon.The gasoline sorption effect is taken into consideration, when considering linear sorption. The numerically solved transport equation take into consideration the dispersion, advection, sorption and the biodegradation of the MTEX compounds and the ethanol, as well. The groundwater velocity field is numerically solved by using the Darcy equations, allowing the regions with different permeabilities to be considered.

  20. A broad model for demand forecasting of gasoline and fuel alcohol; Um modelo abrangente para a projecao das demandas de gasolina e alcool carburante

    Energy Technology Data Exchange (ETDEWEB)

    Buonfiglio, Antonio [PETROBRAS, Paulinia, SP (Brazil). Dept. Industrial; Bajay, Sergio Valdir [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica

    1992-12-31

    Formulating a broad, mixed: econometric/end-use, demand forecasting model for gasoline and fuel alcohol is the main objective of this work. In the model, the gasoline and hydrated alcohol demands are calculated as the corresponding products if their fleet by the average car mileage, divided by the average specific mileage. Several simulations with the proposed forecasting model are carried out, within the context of alternative scenarios for the development of these competing fuels in the Brazilian market. (author) 4 refs., 1 fig., 3 tabs.

  1. Economic study of a water pumping system for traveling gun machine; Estudo economico de uma adutora, para sistema autopropelido de irrigacao, operando com motor diesel e alcool

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Lessandro Coll; Viola, Marcelo R.; Bilibios, Carolina; Oliveira, Henrique F.E. de; Lima Junior, Joaquim A. de [Universidade Federal de Lavras (UFLA), Lavras, MG (Brazil)

    2009-07-01

    This study aimed at comparing the set-up and operation costs of a water pumping system using engines which run on two different fuels (diesel oil and alcohol) for application in traveling gun machines. The study was carried out by considering fuel prices in Minas Gerais State on 10/11/2008. The results showed that annual costs with diesel oil engines (R$ 67,460.64) were less than those for alcohol engines (R$ 82,608.12). Nevertheless, it is worthwhile to point out that the operation with alcohol engines was found to be viable only when this fuel price does not exceed R$ 1.40 per liter. (author)

  2. Mathematical modelling and simulation of the operation in sugar and alcohol industry: 2 - evaporation; Modelagem matematica e simulacao das operacoes da industria de acucar e alcool: 2 - evaporacao

    Energy Technology Data Exchange (ETDEWEB)

    Chiappetta, A; Giudici, R; Nascimento, C A.O. do [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    1987-12-31

    A mathematical model is presented for steady-state simulation of multiple-effects evaporators systems used for concentration of sugar solution. The model basis are the fundamental energy and mass balances equations, as well as empirical correlations for the problem being handled. The evaporation system simulation is performed with an executive program which allows different process configurations. For one typical case, some process parameters (volumetric rate and concentration of feed;exhaust steam temperature) influences on syrup concentration and solution temperature were studied. (author) 8 figs., 2 refs.

  3. Determining the amount of anhydrous alcohol evaporated in vertical cylindrical tanks; Determinacao da quantidade de alcool etilico anidro evaporado em tanques cilindricos verticais

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Elcio Cruz de [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    In order to assess the anhydrous alcohol evaporated amount in vertical cylindrical tanks was developed a calculation methodology based on the rate of mass transfer of the product, the Reynolds number and the mass transfer coefficient. An Excel spreadsheet was prepared with data entry of the tank and physical and chemical properties of the product (temperature and density). For a temperature of 50 deg C, the volume evaporated reaches values of 0.8% by day. (author)

  4. Vapor-liquid equilibrium for the system ethyl alcohol + ester; Equilibrio liquido-vapor para o sistema alcool etilico+ester

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Humberto Neves Maia de; Nascimento, Yuri Corsino do; Chiavone-Filho, Osvaldo [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2004-07-01

    This work consists of the experimental determination of a series of vapor-liquid equilibrium (VLE) data, for mixtures of ethyl alcohol + ester (ethyl acetate), prepared synthetically, that may be present in the production of biodiesel. The separation of the ethyl alcohol from esters by distillation is an important stage of this process, and therefore it demands accurate data for an appropriate modelling, and later optimization via simulators. FISCHER'S ebulliometer, with digital control (Model 602), was used for measurement of VLE data for the system ethyl alcohol + ester. It consists of a recirculation cell of the both vapor and liquid phases, providing complete data, i.e., pressure, temperature and compositions of the liquid and vapor phases that were obtained by gaseous chromatography (PTxy). This apparatus is coupled to a thermostatic bath with cooling (TE-184 TECNAL) that aims to condense the coming steams of the ebullition in order to return to the mixture camera. The VLE data obtained experimentally were submitted to the test of thermodynamic consistence of the deviations, where the equation of Gibbs-Duhem is used, through the model UNIQUAC. The parameters obtained from the experimental data can be applied in the simulators of processes with the purpose of optimizing the separation of the ethyl alcohol of Ester. (author)

  5. Depolymerization of post-consumer PET with multifunctional alcohol through melt processing; Despolimerizacao de PET pos-consumo com alcool multifuncional atraves de processamento por fusao

    Energy Technology Data Exchange (ETDEWEB)

    Lessa, Tathiane C.R.F.; Mendes, Luis C.; Dias, Marcos L., E-mail: tathianecr@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano. Centro de Tecnologia

    2009-07-01

    The purpose of this study was to prepare oligomers from post-consumer PET with multifunctional alcohol, through melt processing, aiming to develop a new material, able to play a role as filler or property modifier. Maintaining constants the process conditions, content and kind of catalyst, the influence of the solvolysis agent on the PET depolymerization was investigated. The products were evaluated by wide-angle X-ray diffraction (WAXD) and thermogravimetry (TG/DTG). The changes in the WAXD curves and the shift of the maximum degradation temperature suggested that the ester linkages were broken being the ethylene glycol moieties replaced with hydroxyl-terminal groups of the multifunctional alcohol, as result of a transesterification reaction. The chemical structure of the new ester was named 'star-branching polymer'. (author)

  6. Padroes de consumo de alcool e fatores associados entre adultos usuarios de servico de atencao basica do Rio de Janeiro, RJ, Brasil

    Directory of Open Access Journals (Sweden)

    Rafael Tavares Jomar

    2014-01-01

    Full Text Available RESUMO Objetivou-se estimar os padrões de consumo de álcool e identificar fatores associados entre usuários adultos de um serviço de atenção básica no município do Rio de Janeiro, Brasil. Desenvolvido através de inquérito domiciliar com amostra de 301 indivíduos que responderam a um instrumento de coleta que continha o Alcohol Use Disorders Identification Test e variáveis de caracterização sociodemográfica e de saúde. A regressão logística foi utilizada para verificar associação entre o padrão de consumo problemático de álcool e as variáveis independentes. Identificaram-se padrões de consumo problemático de álcool entre pessoas do sexo masculino, de cor da pele negra e/ou mestiça, não casadas, sem religião, tabagistas e entre pessoas sem doença crônica acompanhada pela unidade de saúde. Os serviços de saúde devem, portanto, estar preparados para identificar precocemente pessoas que fazem consumo problemático de álcool, a fim de prevenir consequências sociais e de saúde nas populações, espe cial mente nas atendidas pela atenção básica, que tem a promoção da saúde e a prevenção de agravos como práticas sanitárias prioritárias.

  7. Hepatites pós-transfusionais na cidade de Campinas, SP, Brasil: II. Presença dos anticorpos anti-HBc e anti-HCV em candidatos a doadores de sangue e ocorrência de hepatites pós-transfusionais pelo vírus C nos receptores de sangue ou derivados Post-transfusional hepatitis in the city of Campinas, SP, Brazil: II- Presence of anti-HBc and anti-HCV antibodies in blood donors and occurrence of post-transfusional hepatitis C virus in recipients of blood or derivates

    Directory of Open Access Journals (Sweden)

    Fernando Lopes Gonçales Júnior

    1993-02-01

    Full Text Available Pesquisamos os anticorpos anti-HBc e anti-HCV em amostras de soros provenientes de 799 candidatos a doadores, que tiveram suas unidades de sangue ou derivados transfundidas a 111 receptores. O anti-HBc e o anti-HCV foram reagentes, em respectivamente 9 e 2,1% dos doadores testados. Observamos que entre os 111 receptores, 44 haviam recebido pelo menos uma unidade anti-HBc positiva e 67 haviam sido transfundidos somente com unidades anti-HBc negativas. Houve um risco 4,5 vezes maior de aquisição de hepatite por vírus C pelos receptores que receberam pelo menos uma unidade anti-HBc positiva Se a pesquisa do anti-HBc fosse realizada na triagem sorológica dos doadores de sangue, cerca de 56% dos casos de HVC nos receptores saiam evitados. A população de receptores que recebeu pelo menos uma unidade anti-HCV reagente, apresentou um risco 29 vezes maior de adquirir esta hepatite, quando comparada aos receptores transfundidos com todas as unidades anti-HCV negativas. A realização do teste para a pesquisa do anti-HCV na triagem dos doadores de sangue, preveniria 79% dos casos de HVC pós-transfusionais. Os candidatos a doadores brasileiros parecem ser acometidos simultânea ou sequencialmente, pelos vírus B e C das hepatites, pois, 44,4% dos doadores anti-HCV positivos, também foram anti-HBc positivos. A realização dos testes para as pesquisas dos anticorpos anti-HBc e anti-HCV, nas triagens hemoterápicas, está indicada para prevenir a transmissão de hepatites pós-transfusionais, em nosso meio.We have analysed anti-HBc and anti-HCV antibodies in serum samples from 799 donors which had their blood or derivates transfused to 111 recipients. Anti-HBc and anti-HCV were reactive in respectively 9 and 2.1% of the donors tested. We have observed that among the 111 recipients, 44 had received at least one positive anti-HBc unit and 67 had been transfused only with negative anti-HBc, units. The risk of developing hepatitis C virus was 4.5 times

  8. 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.

  9. 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)

  10. 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)

  11. Fuel cell: Brazil is focusing the energy of the millennium; Celula a combustivel: Brasil se prepara para a energia do milenio

    Energy Technology Data Exchange (ETDEWEB)

    Bombana, Clarice [Eletricidade Moderna (EM), Sao Paulo, SP (Brazil)

    2001-10-15

    The fuel cell is characterized as an important way of distributed energy generation, in this direction it can contribute for solution of demand control problems in relation to critical charging periods or energy rationing. Besides other benefits, can be highlighted the silent operation, utilization of residual heat and high quality of produced energy. Attentive to this tendency, COPEL and LACTEC have united efforts in order to diffuse this technology in Brazil.

  12. 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)

  13. 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)

  14. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. Impacts of the turbogenerator reactive operation in the nuclear fuel burnup; Impactos da operacao reativa do turbogerador na queima do combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Helio Ricardo V. de; Martinez, Aquilino S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2002-07-01

    The parameterization of the losses in a turbogenerator in function of an operation with the electrical system reactive allowed to model in a simple and exact way the equations that define and they quantify the additional of nuclear potency that it should be generated by a reactor, in order to maintain the commitment with the national system operator, that is, the electric active power contracted. starting from this additional of nuclear power it was modeled the additional burn up of the fuel elements, as well as the numbers of effective days to full power wasted. it was promoted a safety analysis and some limitations due to the reactive operation of the electrical system. inside of this context it was made a financial evaluation in which we ask some questions to companies and government organs in order to define what losses are acceptable and also the reason why we don't use other technician resources such as: increase of the electrical mesh, electrical power injection in strategic points, capacitor banks and increase of the number the electrical plants. (author)

  20. 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)

  1. 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)

  2. 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)

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. 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.

  8. 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)

  9. 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)

  10. 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)

  11. 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)

  12. Study for application of flexible fuel technology in the Brazilian automobile 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 [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    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 auto mobile market that mixes the use of two fuels (gasoline and ethanol) and their mixtures in the internal combustion engine. (author)

  13. Combustion oil production by direct liquefaction of the black liquor; Obtencao de oleo combustivel atraves da liquefacao direta de lixivia negra

    Energy Technology Data Exchange (ETDEWEB)

    Costa, J L.M. [Universidade Estadual de Maringa, PR (Brazil). Dept. de Quimica; Rodrigues, J A.R.; Schuchardt, U [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

    1985-12-31

    A large number of publications about the liquefaction of carbonaceous materials with carbon monoxide in water have appeared. As carbon monoxide reacts with water to form formate. We have decided to use this compound for the direct liquefaction of black liquor, obtained from the pulp and paper industry. The reactions were performed in a stainless steel autoclave of 1 litre using a ratio of water/black liquor/sodium formate of 69/29,5/1,5 %. The reaction conditions were varied between 200 and 300 deg C and 110 to 130 bar of inert gas. We obtained heavy oils of an average molecular weight around 500 in 90 to 100 % yield on a dry and ash-free basis. The calorific value of this oil was estimated in 38000 kJ/kg. (author). 12 refs., 2 figs., 7 tabs

  14. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  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. 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)

  1. 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)

  2. 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)

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. Sorption of phenol and phenol derivatives in hydrotalcite; Sorcion de fenol y derivados de fenol en hidrotalcita

    Energy Technology Data Exchange (ETDEWEB)

    Avina G, E I

    2002-07-01

    One of the main problems in Mexico and in the World is the waste water pollution of a great variety of industrial processes by organic compounds. Among those ones the phenol compounds which are highly toxic, refractories (to the chemical degradation) and poorly biodegradable. This is due in a large extent to the problem created by the accelerated increase in the environmental pollution in the cities and industrial centers. The phenol compounds are used in a great variety of industries such as the production of resins, plasticizers, antioxidants, pesticides, colourings, disinfectants, etc. These phenol compounds are specially harmful, since they have repercussions on the flora of plants of biological treatment of water affecting its operation. The main objective of this work is to evaluate the capacities of phenol detention and its derivatives in an hydrotalcite type compound and diminishing with it the presence in water, in this case, of solutions prepared in the laboratory. In order to analyse this elimination process was used a methodology based in the carrying out in batch experiments and in the elaboration of a sorption isotherm. It is worth pointing out that this work was realized at laboratory scale, at relatively high phenol concentration ratio. With the obtained results when the sorption properties are evaluated the calcined hydrotalcite (HTC) for detaining phenol and p-chloro phenol it was observed that it is detained greater quantity of p-chloro phenol than phenol in the HTC. The detention of these phenol compounds in the HTC is due to the memory effect by the hydrotalcite regeneration starting from the oxides which are formed by the burning material. (Author)

  9. Biorremediación de suelos contaminados por derrames de hidrocarburos derivados del petróleo en Colombia

    OpenAIRE

    Petro Cardona, Piedad Helena; Mercado Montero, Gabriela Del Carmen

    2014-01-01

    Artículo de revisión como (requisito para optar el título de Ingeniero Químico).-- Universidad de San Buenaventura, Facultad de Ingenierías, Arquitectura, Artes y Diseño, Programa de Ingeniería Química, 2014 En la actualidad, uno de los principales problemas de contaminación de suelos, aire y agua, es el uso incorrecto de materiales y residuos peligrosos debido a la extracción y al manejo del petróleo en todos los países productores de hidrocarburos. El impacto ambiental que ha generado es...

  10. Synthesis and characterization of polyanhydride derived from castor oil; Sintese e caracterizacao de polianidrido derivado do oleo de mamona

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Fernando de M.; Reis, Roberta Yonara Nascimento; Nobre, Francisco X.; Matos, Jose M.E., E-mail: robertayonara@gmail.com [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

    2015-07-01

    Polyanhydrides are biopolymers already used as drug carriers, that allow the controlled release of the drug in vivo. Currently, these polymers are produced from a polyol, such as ethyleneglycol. In this work we synthesized a polyanhydride from castor oil, from the derivatization of oil via alcoholysis reaction. The oil was then converted to a monoglyceride (MG) by alcoholysis reaction at 140 °C. The MG reacted with phthalic anhydride (PA) at 100 °C, forming the polymer P1. The polymer was characterized by FT-IR, {sup 1}H and {sup 13}C NMR. These techniques allowed confirmation of the polymer formation. (author)

  11. SINTESIS, CARACTERIZACION Y ELECTRO-OXIDACION DE 2,2- DITIENIL DERIVADOS, EFECTO DE LA FUNCIONALIZACION SOBRE LAS PROPIEDADES ELECTRICAS

    OpenAIRE

    BROVELLI SEPULVEDA, FRANCISCO ANTONIO

    2002-01-01

    Desde el descubrimiento de la conducción eléctrica en sistemas poliméricos, se han realizado muchos esfuerzos con el propósito de mejorar tanto la conductividad como la resistencia mecánica de estos materiales, sin embargo, en la última década, se ha manifestado un gran interés por los sistemas semiconductores para el desarrollo de nuevos dispositivos, como por ejemplo, diodos emisores de luz (OLED). Debido a la versatilidad estructural que presentan los polímeras, se ha propuesto la sí...

  12. Evaluación sensorial de derivados cárnicos de carne de babilla (Caiman crocodilus crocodilus

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Alarcón García

    2010-12-01

    Full Text Available El objetivo de este trabajo fue analizar sensorialmente dos productos cárnicos (jamón de alta inyección y costillas ahumadas elaborados con base en carne de babilla (Caiman crocodilus crocodilus. Se utilizaron 21 animales con tallas entre los 90 y 120 cm de largo, los cuales procedían del Zoocriadero Santa Ana, situado en la ciudad de Villavicencio, Meta, Colombia. El análisis proximal (% grasa, % humedad, % proteína de los productos cárnicos elaborados fue realizado en el Laboratorio de Nutrición de la Facultad de Medicina Veterinaria y de Zootecnia de la Universidad Nacional de Colombia para confirmar su clasificación como Categoría Premium según la Norma Técnica Colombiana 1325, quinta actualización (ICONTEC, 2008. Se realizaron paneles de aceptación con visitantes ocasionales en el Centro Agroindustrial del Servicio Nacional de Aprendizaje del Meta (sede Hachón, en la Feria Agroindustrial de Catama y almacenes Éxito, sucursal Sabana; todos en Villavicencio, Meta, Colombia; completando un total de 400 evaluaciones tanto de jamón como de costillas ahumadas. Se aplicó estadística descriptiva para establecer el grado de aceptación para lo cual se establecieron cuatro niveles de aprobación posible en que se podían clasificar los productos, siendo estos niveles determinados por características como color, textura, sabor y olor. El jamón y las costillas ahumadas elaboradas con carne de babilla presentaron altos niveles de aceptación para las características de textura, sabor y olor a diferencia del color, lo cual se atribuyó al color pálido característico de la carne de babilla que contrasta con el color típico de los productos cárnicos de res y de cerdo, el cual es asociado normalmente por el consumidor a productos cárnicos con atributos de frescura y salubridad. Los valores de aceptación tanto para jamón de babilla como para costillas ahumadas de babilla fueron del 99 %.

  13. Evaluación sensorial de derivados cárnicos de carne de babilla (Caiman crocodilus crocodilus

    Directory of Open Access Journals (Sweden)

    William Raúl Mayorga Rodríguez

    2010-01-01

    Full Text Available El objetivo de este trabajo fue analizar sensorialmente dos productos cárnicos (jamón de alta inyección y costillas ahumadas elaborados con base en carne de babilla (Caiman crocodilus crocodilus. Se utilizaron 21 animales con tallas entre los 90 y 120 cm de largo, los cuales procedían del Zoocriadero Santa Ana, situado en la ciudad de Villavicencio, Meta, Colombia. El análisis proximal (% grasa, % humedad, % proteína de los productos cárnicos elaborados fue realizado en el Laboratorio de Nutrición de la Facultad de Medicina Veterinaria y de Zootecnia de la Universidad Nacional de Colombia para confirmar su clasificación como Categoría Premium según la Norma Técnica Colombiana 1325, quinta actualización (ICONTEC, 2008. Se realizaron paneles de aceptación con visitantes ocasionales en el Centro Agroindustrial del Servicio Nacional de Aprendizaje del Meta (sede Hachón, en la Feria Agroindustrial de Catama y almacenes Éxito, sucursal Sabana; todos en Villavicencio, Meta, Colombia; completando un total de 400 evaluaciones tanto de jamón como de costillas ahumadas. Se aplicó estadística descriptiva para establecer el grado de aceptación para lo cual se establecieron cuatro niveles de aprobación posible en que se podían clasificar los productos, siendo estos niveles determinados por características como color, textura, sabor y olor. El jamón y las costillas ahumadas elaboradas con carne de babilla presentaron altos niveles de aceptación para las características de textura, sabor y olor a diferencia del color, lo cual se atribuyó al color pálido característico de la carne de babilla que contrasta con el color típico de los productos cárnicos de res y de cerdo, el cual es asociado normalmente por el consumidor a productos cárnicos con atributos de frescura y salubridad. Los valores de aceptación tanto para jamón de babilla como para costillas ahumadas de babilla fueron del 99 %.

  14. Biodiesel renovável derivado de microalgas: avanços e perspectivas tecnológicas

    Directory of Open Access Journals (Sweden)

    Claudio M. P. Pereira

    2012-01-01

    Full Text Available Microalgae are a promising source of raw material for biodiesel production. This review discusses the latest developments related to the application of microalgae biomass for biodiesel production. Characterization of fatty acid of microalgae and comparisons with other sources of raw materials and processes are presented. Furthermore, technological perspectives and approaches for growing microalgae in photobioreactors, microalgal oil extraction techniques, and procedures for synthesizing biodiesel are reviewed.

  15. Niveles del factor de crecimiento derivado de plaquetas en el plasma rico en plaquetas antes y despues de antiagregantes plaquetarios

    Directory of Open Access Journals (Sweden)

    Maczy González

    2013-09-01

    Full Text Available El PDGF es uno de los mitógenos más potentes para el tejido conectivo, su secreción parece ser particularmente importante cuando la fuente es el Plasma Rico en Plaquetas (PRP, de allí el rol protagónico de este último en la regeneración tisular. Se determinó mediante ELISA los niveles de PDGFBB en el PRP, Plasma Pobre en Plaquetas (PPP y Exudado de 32 sujetos sanos antes y 24 horas después de ingerir AAS (Aspirina y Clopidogrel. Los niveles basales de PDGFBB ueron de 10, 6 ± 1, 9 ng/ml (PPP, 12, 12 ± 2, 5 ng/ml (PRP y 10, 84 ± 1, 68 ng/ml (Exudado. Mientras que después del tratamiento con AAS las concentraciones de PDGFBB estuvieron en 8, 96 ± 1, 4 ng/ml (PPP, 11, 36 ± 1, 48ng/ml (PRP, 11, 11 ± 1, 14ng/ml (Exudado y para el Clopidogrel fueron de 8, 53 ± 0, 59 ng/ml (PPP, 9, 65 ± 1, 17 ng/ml (PRP y 8, 51 ± 0, 75 ng/ml (Exudado. Se notó que luego de la administración de AAS y Clopidogrel los valores de PDGFBB disminuyeron de manera estadísticamente significativa, en especial para el grupo del Clopidogrel. El AAS pareció afectar en menor grado las concentraciones de PDGFBB, lo cual puede ser atribuible al mecanismo de acción farmacológica diferencial existente entre la AAS y Clopidogrel. No se encontró correlación entre el recuento plaquetario y los niveles basales de PDGFBB del PRP. PDGF levels in platelet-rich plasma before and after anti platelets drugs Abstract PDGF is one of the most potent mitogen for connective tissue, its secretion appears to be particularly important when the source is Platelet Rich Plasma (PRP, hence the latter leading role in tissue regeneration. ELISA PDGFBB levels in PRP, Platelet Poor Plasma (PPP and exudates, were determined in 32 healthy subjects before and 24 hours after ingestion of Aspirin (ASA and Clopidogrel (CLO. PDGFBB baseline levels were 10.6 ± 1.9 ng / ml (PPP, 12.12 ± 2.5 ng / ml (PRP and 10.84 ± 1.68 ng / ml (exudate. After treatment with ASA concentrations were PDGFBB in 8.96 ± 1.4 ng / ml (PPP, 11.36 ± 1.48 ng / ml (PRP, 11.11 ± 1.14 ng / ml (exudate and the Clopidogrel were 8.53 ± 0.59 ng / ml (PPP, 9.65 ± 1.17 ng / ml (PRP and 8.51 ± 0.75 ng / ml (exudate. It was noted that after the administration of ASA and CLO, PDGFBB values statistically significantly decreased, especially for the group of CLO. ASA lesser extent appears to affect th concentrations of PDGFBB, which may be attributable to the pharmacological mechanism of action between the ASA and Clopidogrel. No correlation was found between platelet count and baseline levels of PRP PDGFBB.

  16. Síntese de derivados acilados da D-ribono-1,4-lactona catalisada por lipases

    OpenAIRE

    Sebrão, Damianni

    2005-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química. A lipase de Pseudomonas cepacia (LPS) foi imobilizada em filmes de caseinato de sódio-CS, o sistema caracterizado por MEV, e a quantidade de água determinada por titulação de Karl-Fisher. O sistema LPS/CS foi usado como catalisador na preparação do oleato de n-pentila, avaliando o efeito do solvente orgânico. Os solventes com log P > 2,5 foram os ...

  17. Efecto citotóxico de algunos compuestos naturales aislados de plantas Laureaceae y derivados sintéticos

    Directory of Open Access Journals (Sweden)

    Luis Enrique Cuca

    2011-03-01

    Conclusión. Los compuestos evaluados que exhibieron actividad contra la proliferación celular mostraron resultados interesantes, lo cual sugiere su potencial uso como cabezas de serie o moléculas plantilla en el desarrollo de agentes anticancerígenos.

  18. Efectos derivados de la puesta en práctica del marketing de relaciones en los servicios profesionales

    OpenAIRE

    Filho, Paulo Freire de Carvalho; Camarero Izquierdo, Carmen

    2003-01-01

    [ES]El objetivo del presente trabajo es identificar la influencia sobre el consumidor y sobre el resultado empresarial de dos dimensiones básicas de los servicios profesionales: la dimensión formal o calidad del servicio prestado y la dimensión informal o interacción personal con el cliente. Sobre la base teórica del marketing de relaciones, se analiza cómo influyen los aspectos formales e informales del servicio en el proceso de mantener e intensificar las relaciones con el cliente. Para ...

  19. Determinación de las variables significativas en la obtención de 2 derivados de quitina

    Directory of Open Access Journals (Sweden)

    Sol Amalia Fernández Monagas

    2002-08-01

    Full Text Available Al aplicar un diseño factorial fraccionario 27-4 se determinó que las variables más significativas para la introducción de grupos carboxilo en la molécula de quitina son: el tiempo de reacción con ácido monocloroacético, la concentración de ácido monocloroacético, la temperatura de pretratamiento de la quitina con el hidróxido de sodio y la concentración de hidróxido de sodio. Las variables más significativas en la formación de grupo amino resultaron ser la concentración de ácido monocloroacético, la temperatura de reacción con ácido monocloroacético, la temperatura de pretratamiento de la quitina y la concentración de hidróxido de sodio.After applying a fraction factor design 27-4, it was determined that the most significant variables for the introduction of carboxyl groups in the chitin molecule were time of reaction with monochloroacetic acid, the concentration of this acid, the pre-treatment temperature of chitin with sodium hydroxide, and the concentration of sodium hydroxide. The most significant variables in the formation of the amino group were the concentration of monochloroacetic acid, the reaction temperature with monochloroacetic acid, the pre-treatment temperature of chitin and the concentration of sodium hydroxide.

  20. Sintesis y evaluación biológica de nuevos derivados de tipo imidazolina y etanolamina fluorados

    OpenAIRE

    Flores Penalba, Sonia

    2011-01-01

    Una de las principales áreas de interés de la química orgánica es la búsqueda de nuevos compuestos con actividad biológica. En este sentido cabe destacar el especial interés que despiertan los compuestos nitrogenados debido a que constituyen una de las familias más numerosas entre las biomoléculas y que están implicados en múltiples procesos a nivel metabólico y estructural. Un ejemplo representativo los constituyen los compuestos de tipo etanolamina, ampliamente estudiados por sus variad...

  1. Batch sequencing of oil derivates in pipeline networks; Sequenciamento de bateladas de derivados leves de petroleo numa rede dutoviaria

    Energy Technology Data Exchange (ETDEWEB)

    Bonacin, Mario Vicente; Oliveira, Daniel Rossato de; Czaikowski, Daniel Irineu; Polli, Helton Luis; Magatao, Leandro; Stebel, Sergio Leandro; Neves Junior, Flavio [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Ribas, Paulo Cesar [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    This work presents a computational tool to assist the operational scheduling of a pipeline network. In this network, transfer of products is carried out by batches, from a source to a destination. This tool implements a proposal to determine priorities of the outgoing batches as well as alternatives for sequencing them fulfilling the stated periods stipulated. This proposal uses an analysis of production and demand plans, stockage, products draining in terminals, as well as operational restrictions of the pipeline network, looking for optimizing the use of resources such as pipes, bombs and tanks. The scenario in study is composed by 14 areas (4 refineries, 2 harbours, 6 distribution centres and 2 costumers) and 29 pipes. Prioritizing the attendance to the areas of source or demand, the algorithm carries choices between routes and possible batches volumes, considering calculations of time windows, that determine the limited interval when transference operations must occur. Moreover, operations called 'lung' are also treated, which involve flow changes during the movement. (author)

  2. Los procesos de aprendizaje derivados del estimulo a la participation de los trabajadores en la gestion medioambiente

    DEFF Research Database (Denmark)

    Lorentzen, Børge

    1997-01-01

    The article presents conclusions from the action research project "Employee participation in the introduction of cleaner technologies", which was carried out in fice Danish companies in 1993-95.The project was focusing on the role of employees and their elected refpresentatives in the prevention ...

  3. Characterization of derivates of carbo-anhydride by NMR; Caracterizacao de derivados do anidrido carbico por RMN

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Marcos Pery Amaral [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Bergter, Lothar [Cia. Souza Cruz, Rio de Janeiro, RJ (Brazil); Seidl, Peter Rudolf [Centro de Tecnologia Mineral, Rio de Janeiro, RJ (Brazil)

    1994-12-31

    The term molecular recognition may be applied to several phenomena of different complexities. The compounds which work as blockers or acceptors in this process are generally complexes with functional groups positioned in specific positions. This work presents the NMR characterization of carbo-anhydride derivates which are important in the preparation of synthetic acceptors 2 figs.

  4. Síntesis de oxitocina en fase sólida usando derivados de terbutoxicarbonilo y fluorenilmetoxicarbonilo

    OpenAIRE

    Calvo, Julio C; Barrera, Nubia F.; García, Josué A.; Guzman, Fanny; Espejo, Fabiola; Patarroyo, Manuel E.

    2010-01-01

    La oxitocina, péptido cíclico cuya secuencia es CYIQNCPLG, fué el primer péptido de importancia biológica que pudo ser sintetizado. En este trabajo se compara la síntesis de la oxitocina usando resina p metilbenzhidrilamina (MBHA) para la síntesis por estrategia t-Boc y resina Rink p-metilbenzhidrilamina (Rink MBHA) para la síntesis por estrategia Fmoc, con altos rendimientos. El péptido crudo se ciclizó en una disolución acuosa de dimetilsulfóxido al 10%. La caracterización se llevó a cabo p...

  5. Interaction of derived polymers from pyrrole with biocompatible solutions; Interaccion de polimeros derivados de pirrol con soluciones biocompatibles

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, O. G.

    2010-07-01

    This work presents a study about the synthesis by plasma, the electric properties and superficial interaction of polymers derived from pyrrole doped with Iodine with potential use as bio material. Poly-pyrrole is a semiconductor and biocompatible polymer with potential application in the development of artificial muscles and implants where the electric interaction between cells and material is an important variable. The syntheses were made at 13.5 MHz in a glass tubular reactor of 1500 cm{sup 3} with electrodes of 6.5 cm diameter and stainless steel flanges. An electrode was connected to the RF terminal of the power supply that is combined with a matching coupling resistance. The monomer and dopant used in this work were pyrrole and Iodine respectively, in closed containers. They were vaporized and injected separately into the reactor at room temperature and 0.1 mbar. The vapors of the reagents mixed freely in the reactor. The synthesis time was 240 min at 40, 60, 80 and 100 W. The polymers were obtained as thin films adhered to the reactor walls. The films were washed and swollen with distilled water and removed from the reactor walls with a small spatula. The polymers were irradiated with gamma rays at 18 and 22 KGy. Due to the fact that the doses are cumulative, the final dose applied was 40 KGy. The polymers characterization was carried out by Fourier Transform Infrared Spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy, contact angle, electrical conductivity and X-ray diffraction. The analyses indicates that the polymers have very similar structure in almost the entire power range, showing C-O, C=C, C-H, O-H, N-H bonds with a predominantly amorphous structure. The TGA analyses showed that the material has 4 or 5 loses of material. The first one starts after that 115 C except for the material irradiated at 40 KGy, this one begins in 87 C, the second one is in the interval of 196 and 295 C, the third one between 311 and 500 C, and the last one after that 760 C and even at 800 C. The morphological studies showed that the polymers are formed by compact layers. The contact angles of the materials are less than 85, due to this fact, the polymers can be considered hydrophilic materials. The polymers have conductivity in the interval of 6 x 10{sup -1} to 1 x 10{sup -2} S/m. When the polymers were irradiated with gamma rays, they showed a major presence of C-I (2361 cm{sup -1}) and C=O (2346 cm{sup -1}) bonds. The intensity of the C-I bond decrease, but it can be appreciated in other absorptions. After the last irradiation, the contact angle was the lowest for all the materials, which is less than 58. The irradiated polymers showed less conductivity than the polymers without irradiation, besides they have a displacement in the amorphous center. (Author)

  6. SINTESIS Y CARACTERIZACIÓN DE UN DERIVADO DE LA CICLOHEXANONA DE TIPO CHALCONA , COMO UNA EXPERIENCIA INTEGRAL DE LABORATORIO.

    Directory of Open Access Journals (Sweden)

    Perla E. Hernández González

    2015-01-01

    Full Text Available Actualmente los profesores de química están en la búsqueda de nuevos modelos que permitan experiencias de laboratorio integradoras, donde convergen conocimientos interdisciplinarios del área de química. Con este marco de ideas este trabajo describe la síntesis y caracterización del compuesto (2 E , 6 E - 2,6 - bis(4 - metoxi benzilideno ciclohexanona , como eje motor del conocimiento, para invitar al alumno a desarrollar sus habilidades cognitivas, como pensamiento crítico y resoluc ión de problemas, así como interpret ación y análisis de resultados. Se sintetizó el compuesto por una reacción de condensación de Claisen - Schmidt, involucrando un aldehído aromático y ciclohexanona. El compuesto fue caracterizado espectroscópicamente por RMN, IR, y UV - Vis. Se realizaron pruebas de solubilidad y punto de fusión. La estructura química fue confirmada por difracción de rayos X (RX de un monocristal. En conclusión, esta experiencia de laboratorio permite a los estudiantes involucrarse con téc nicas y procedimientos usados comúnmente en el laboratorio de química orgánica para la síntesis y caracterización de compuestos orgánicos.

  7. Synthesis and evaluation of antimalarial activity of curcumin derivatives; Sintese e avaliacao da atividade antimalarica de compostos derivados da curcumina

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Patricia Ramos; Miguel, Fabio Balbino; Almeida, Mauro Vieira de; Couri, Mara Rubia Costa [Universidade Federal de Juiz de Fora (UFSJ), MG (Brazil). Instituto de Ciencias Exatas. Departamento de Quimica; Oliveira, Michael Eder de; Ferreira, Vanessa Viana; Guimaraes, Daniel Silqueira Martins; Lima, Aline Brito de; Barbosa, Camila de Souza; Oliveira, Mariana Amorim de; Almeida, Mauro Vieira de; Viana, Gustavo Henrique Ribeiro; Varotti, Fernando de Pilla, E-mail: varotti@ufsj.edu.br [Universidade Federal de Sao Joao Del Rei (UFSJ), MG (Brazil). Centro de Ciencias da Saude; others, and

    2014-05-15

    ne of the main challenges in the development of new antimalarial drugs is to achieve a viable lead candidate with good pharmacokinetic properties. Curcumin has a broad range of biological activities, including antimalarial activity. Herein, we report the antimalarial activity of six curcumin derivatives (6-12) and an initial analysis of their pharmacokinetic properties. Five compounds have demonstrated potent activity against the P. falciparum in vitro (IC{sub 50} values ranging from 1.7 to 15.2 μg mL{sup -1}), with moderate or low cytotoxicity against the HeLa cell line. The substitution of the carbonyl group in 6 by a 2,4-dinitrophenylhydrazone group (to afford 11) increases the Selective Index. These preliminary results indicate curcumin derivatives as potential antimalarial compounds. (author)

  8. Estimación de costes ambientales derivados del corredor La Salve-Ibarrekolanda. Bilbao-España

    OpenAIRE

    Saiz de Omeñaca, Jesús; Ereño, Iñaki; Saiz de Omeñaca, M. Glori; Solar, Marta; Aguirre, Íñigo; Camús, Antonio; Gómez Poncela, Juan M.; Saiz de Omeñaca, José; Villar, Egenio

    1993-01-01

    This paper summarizes the Information on two alternative routes for a highway between the ''La Salve'' Bridge and Ibarrekolanda (Bilbao) in order to assess and compare the environmental costs. The first alternative would involve passing a high-speed road through a densely populated area whereas the second would have more characteristics of a ring road. As expected, the second alternative, which bypasses the built-up areas, would have less impact and lower environmental costs for the inhabitan...

  9. Riesgos derivados de la exposición a dosis bajas de radiación ionizante

    Directory of Open Access Journals (Sweden)

    Almudena Real Gallego

    2010-12-01

    Full Text Available La radiación ionizante ha mostrado tener diversas aplicaciones beneficiosas para el hombre, pero también puede dañar la salud de las personas y el medio ambiente. Para proteger adecuadamente al hombre de los posibles efectos nocivos de la radiación ionizante es imprescindible conocer en detalle los efectos biológicos producidos por esta, sus características y los distintos factores que influyen en dichos efectos. Ese es el objetivo de este artículo: describir el estado actual del conocimiento sobre los efectos biológicos que puede producir la radiación ionizante, con especial énfasis en aquellos efectos que se producen tras la exposición a dosis bajas.

  10. Dimensionamento da frota de navios de derivados claros para cabotagem: proposta de modelo de otimização

    Directory of Open Access Journals (Sweden)

    André Augusto Soares Vieira

    2017-10-01

    Full Text Available The Oil & Gas sector relies mainly on the maritime transport to ship large volumes of petroleum and products. In this sense, this paper proposes a mixed integer linear model whose objective is to determine the coastal navigation fleet size and the type of vessels to transport clean petroleum products of real company. The model’s outcome helped programmers define how many ships are actually required to meet the commitments undertaken within a pre-established planning horizon. Comparing the model’s result with the actual number of vessels available for programming, one can eventually release ships to make other journeys, thus avoiding the hiring of ships in Voyage Charter Party for this last purpose. It is also possible to reduce the demurrage in periods of low movement, when the fleet contracted becomes oversized.

  11. Synthesis by plasma and characterization of compounds derived from polyacetylene; Sintesis por plasma y caracterizacion de compuestos derivados del poliacetileno

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez O, M

    2004-07-01

    This work presents a study on, the synthesis by plasma and the characterization of an aliphatic conjugated polymer, polyacetylene-chlorinated (Pac), and two aromatic polymers, Poly pyrrole (P Py-Cl) and Poly thiophene (Pth-Cl) synthesized with chlorine and the electrical conductivity. The last two polymers were synthesized to compare the chlorine-polymer interaction in aliphatic and aromatic polymers synthesized by plasma and their repercussion on the electrical transport of charges in the material. The structure and morphology of the polymers were studied using scanning electron microscopy (Sem), energy dispersive spectroscopy (EDS), infrared spectroscopy (Ft-IR), conductivity analysis and X-Ray photon spectroscopy (XPS). The results showed that Pac is soluble in acetone and other organic solvents, which indicates a low proportion of crosslinking in the polymers. This point is important because the crosslinking reduces the electrical conductivity in the material. The Pac conductivity is in the range of 1 x 10{sup -12} to 6 x 10{sup -4} S/cm in the internal of 35- 90% of relative humidity. A possible mechanism for the transport of electrical charges in Pac is by means of the double and simple conjugated bonds in the polymers. Pth-Cl and P Py-Cl present electric conductivity in the interval of 9 x 10{sup -5} to 1 x 10{sup -2} S/cm and show a great dependence on the relative humidity. The chlorine addition in these polymers was through simultaneous polymerization with chloroform. This last compound can decompose if the energy of the plasma is relatively high, and the fragments can link to the polymer in a hybrid process of copolymerization. An important point of this work is that the polymer is soluble, a difference of the obtained via plasma as the poli aniline, P Py-CI and Pth-Cl both studied in this work. If took in account that the Pac is single the monomer and that P Py-Cl and Pth-CI is affected by the chlorine that modifies the conductivity of the material, then Pac presents an electrical conductivity greater that P Py-Cl and Pth-Cl. (Author)

  12. Natural gas conversion new route using halogen derivatives; Nova rota de conversao de gas natural utilizando derivados halogenados

    Energy Technology Data Exchange (ETDEWEB)

    Noronha, Leandro A.; Mota, Claudio J.A. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Centro de Tecnologia]. E-mail: noronha@iq.ufrj.br; Sousa Aguiar, E. Falabella [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2003-07-01

    Natural gas will have important position in the next decades. Nowadays, there is high demand for petrochemicals products, such as ethene and propene. With the nafta price variation, the development of alternative routes from natural gas will be stimulate, as occur in Rio de Janeiro. Between the main technologies for the natural gas use, arise the gas to liquids (GTL) routes for the conversion to hydrocarbons. Therefore, will be studied the transformation of methyl chloride to light olefins (ethene and propene) and other hydrocarbons in zeolitic catalysts. All of these reactions will be simulate occurring in the zeolitic surface, using a cluster that represents very much the catalyst structure. (author)

  13. Estudio de factibilidad de procesadora de derivados de maracuyá. Una alternativa de desarrollo en Santa Elena, Ecuador Autores

    Directory of Open Access Journals (Sweden)

    Tigrero-González, Félix

    2016-04-01

    Full Text Available The present study aims to determine the technical and financial feasibility of processing derived products from passion fruit, through the setting–up of a production and marketing company in the commune “Las Balsas” - Santa Elena city, Guayas province, Ecuador, where the company will be located. This place has a geographical and climatological location that is appropriate for the growing of passion fruit which facilitates obtaining raw materials throughout the year. The social impact of the company is positive since it demands workers for its operation which will be found in the same sector, plus the use of clean technology for environmen- tal conservation, besides the test of a hypothesis that the setting–up of a processing plant of passion fruit will generate social and economic benefits that allows a better standard of life of the inhabitants of this commune and province.

  14. Docking molecular de derivados de 2-fenilindano-1,3-dionas inibidores da enzima HMG-CoA

    Directory of Open Access Journals (Sweden)

    R. Q. Pordeus

    2014-11-01

    Full Text Available As doenças cardiovasculares constituem uma das principais causas de mortes em todo o mundo. Estudos mostram que a enzima HMG-CoA é considerada uma precursora da via metabólica hipolipidêmica no soro sanguíneo. Na busca por uma nova classe de compostos aptos a inibir esta enzima e consequentemente reduzir os níveis de colesterol, as 2-fenilindano-1,3-dionas apresentam resultados promissores. Uma das maneiras de avaliar o poder farmacológico destes compostos e predizer análogos ainda mais potentes consiste na avaliação da interação entre fármaco (2-fenilindano-1,3-diona e enzima (HMG-CoA, em que se utiliza da técnica de modelagem molecular docking. Neste estudo, o procedimento computacional para obtenção dos resultados de docking foi feito através do software AutoDock 1.5.6. Para avaliar a interação no sítio ativo da HMG-CoA, utilizamos, dentre a série de congêneres, o composto 2-(2-clorofenilindano-1,3-diona. De acordo com os resultados obtidos, foi identificada uma interação hidrofílica importante, do tipo ligação de hidrogênio C=O∙∙∙H–N, a qual apresenta uma distância de 1.62 Å entre os grupos carbonila do anel diona e o aminoácido metionina da HMG-CoA. Outra ligação de hidrogênio p∙∙∙H–N com distância de 3.10 Å formada entre o anel aromático do grupo indano-1,3-diona e o aminoácido glicina também foi identificada.

  15. Incidence des politiques en matière de publicité, de taxes et d ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Incidence des politiques en matière de publicité, de taxes et d'établissement des prix sur la consommation d'alcool (Argentine, Bolivie, Chili, Pérou). La consommation d'alcool ... Corruption in Latin America. This project will study private sector efforts to promote better compliance with anticorruption laws in Latin America.

  16. 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)

  17. Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, C

    1962-07-01

    After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

  18. Effect of layered silicate content on the morphology and thermal properties of Poly(vinyl alcohol) films; Efeito do teor de silicato em camadas na morfologia e propriedades termicas de filmes de poli(alcool vinilico)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jessica R.M.B. da; Santos, Barbara F.F. dos; Leite, Itamara F., E-mail: jraquell@homail.com [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Centro de Tecnologia. Departamento de Engenharia de Materiais

    2015-07-01

    This study aims to evaluate the effect of layered silicate content on the morphology and thermal properties of PVA films. The PVA/layered silicate (AN) films were prepared by intercalation solution, using 1 to 2% of bentonite with respect to the PVA total weight. Then the films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). Results of the FTIR revealed interaction between the functional groups of the PVA and the layered silicate. The XRD analysis showed that nanocomposites with intercalated and partially exfoliated morphology were obtained. The results of TG showed that the nanocomposite PVA/2%AN showed higher thermal stability compared to PVA/1%AN. The DSC results showed that the addition of AN to the PVA did not affect crystallization rate, as well as promoted a reduction in glass transition temperature and melting of the PVA. (author)

  19. Influence of the temperature on the synthesis of CdS quantum dots stabilized with poly (vinil alcohol); Influencia da temperatura na sintese de pontos quanticos de sulfeto de cadmio estabilizados por poli (alcool vinilico)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Semiconductor nanoparticles (Quantum Dots, QDs) have been the subject of recent research by presenting quantum properties. This property has stimulated the study of these particles in biological applications such as bookmarks, which creates the necessity of using different synthesis routes resulting in biocompatible systems. Thus, this study aimed to evaluate the effect of temperature on the properties of QDs cadmium sulfide, aqueous route using poly (vinyl alcohol), a biocompatible polymer, such as stabilizing agent. The characterization of particles produced was performed by UV-Vis spectroscopy and photoluminescence (PL) spectra for obtaining the absorption and emission, respectively and Transmission microscopy (TEM) for analysis of the diameter of the nanocrystals. (author)

  20. Utilization of diesel fuel, anhydrous ethanol and additives blend of a stationary diesel engine with rotatory pump; Utilizacao de mistura ternaria alcool, diesel e aditivo em motores do ciclo diesel com bomba de injecao rotativa

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Cruz, Yordanka; Cavado Osorio, Alberto [Centro de Pesquisas de Petroleo (CEINPET), Havana (Cuba); Belchior, Carlos Rodrigues Pereira; Pereira, Pedro P.; Pinto, Nauberto Rodrigues [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Dept. de Engenharia Naval e Mecanica; Aranda, Donato A. Gomes [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2008-07-01

    In this paper is analyzed the performance and fuel consumption of a stationary Diesel engine, with rotary diesel fuel injection pump, using (diesel fuel + anhydrous ethanol + 0.5% additive) blend. The engine performance parameters and fuel consumption tests were performed at the Termic Machine Laboratory, located in Federal University of Rio de Janeiro, and evaluated using a MWM Series 10 model 4.10 TCA. Two test cycles were used for this test program: the tests were carried out starting from the base diesel S-500, used as a reference; the engine operated with (diesel fuel S-500 - 8% anhydrous ethanol - DIOLEFECT additive (0,5% SPAN80 + 0,1% Biomix-D)) blend. The results indicate that: the reduction levels in power and torque of engine are approximately the same which is (2,55{+-}2%), the brake specific fuel consumption increased in 1,8%. (author)

  1. Synthesis and characterization of particles derived of poly(vinyl alcohol) (PVA) for treatment of embolization and chemoembolization;Sintese e caracterizacao de particulas derivadas de poli(alcool vinilico) (PVA) para embolizacao e quimioembolizacao

    Energy Technology Data Exchange (ETDEWEB)

    Semenzim, Vinicius L.; Basso, Glaucia G.; Passos, Rodrigo A.; Nery, Jose G. [UNESP, Sao Jose do Rio Preto, SP (Brazil); Agreli, Guilherme; Oliveira, Ana P.M.L.; Kawasaki-Oyama, Rosa S.; Braile, Domingo M., E-mail: nery@ibilce.unesp.b [Braile Biomedica Industria e Comercio Representacoes S.A., Sao Jose do Rio Preto, SP (Brazil)

    2009-07-01

    The most effective way to treat cancerous tumors is by surgically removing them. However in some types of cancer, such as liver and uterine cancer, more than two-thirds of patients have no indication for surgery due to the size and location of the tumor, such as into the blood vessels. Doctors and researchers have invested in alternative and less invasive methods such as chemoembolization. The objectives of this research project are the synthesis and characterization of poly(vinyl alcohol) (PVA) particles for use in cancer treatment. PVA particles will be combined with chemotherapeutic agent Doxorubicin, drug commonly used in the treatment of cancers and carcinomas. The particles, obtained by controlled polymerization reaction followed by saponification, were characterized by SEM, XRD and NMR-CP/MAS. The functionalization of the particles with the drug is the next step of this study. (author)

  2. Occupational health II: the work process and the occupational risks in the patio of an alcohol distillery; Saude do trabalhador II: o processo de trabalho e as cargas laboriais no patio de uma destilaria de alcool

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo Pinheiro, Sandra de; Ruffino Netto, Antonio [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Medicina Social

    1994-10-01

    This work is part of a study performed with workers of an alcohol distillery in the region of Ribeirao Preto, Sao Paulo State - Southeast Brazil. It describes the work process in the patio of an alcohol distillery, and shows the occupational risks existing in the area 11 refs.

  3. Deuterium isotopic effects connected with unimolecular and concerted mechanisms. The case of 1-deutero-2-chloro alcohols; Effets isotopiques du deuterium attaches a des mecanismes unimoleculaires et concertes. Cas des deutero-1-chloro-2 alcools

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, C

    1962-07-01

    After a bibliographic analysis of the probable causes of isotopic effects and their comparison, with the simplifications provided by the athermal model, a discussion of the isotopic effect of deuterium in organic molecules in terms of structural influences is presented, showing the important role of the C-D bond length which is shorter than the C-H bond length, and of the D atom's Van der Waals radius, shorter than that of the H atom. Kinetic measurements were carried out on some reactions involving the mechanisms proposed: unimolecular ionizations and halogen concentrates. The structural models chosen are: 2-chloro-cyclo-hexanols cis and trans 1-H and 2-D; 2-chloro-cyclo-pentanols cis trans 1-H and 1-D; 1-phenyl-l-chloro-2-propanol threo 2-H and 2-D. (author) [French] Apres une analyse bibliographique des causes probables d'effets isotopiques et leur comparaison, avec les simplifications qu'apporte le modele athermique, on a entrepris l'etude de la discussion isotopique du deuterium dans des molecules organiques en termes d'influences structurelles, cherchant a degager le role important de la longueur de la liaison C-D plus courte que C-H, et du rayon de Van der Waals de l'atome de D plus petit que celui de H. On a effectue des mesures cinetiques sur quelques reactions invoquant les mecanismes envisages: ionisations unimoleculaires et concentrees d'halogenes. Les modeles structuraux choisis sont: chloro 2 - cyclohexanols cis et trans H 1 et D 1; chloro 2 - cyclopentanols cis et trans H 1 et D 1; phenyl 1 - chloro 1 - propanol 2 threo H 2 et D 2. (auteur)

  4. Scaffold of chitosan/poly(vinyl alcohol) blend chemically crosslinked by glutaraldehyde for tissue engineering applications;Constructos de blendas de quitosana/poli(alcool vinilico) reticulados quimicamente com glutaraldeido para aplicacao em engenharia de tecido

    Energy Technology Data Exchange (ETDEWEB)

    Costa Junior, Ezequiel de S., E-mail: escjr50@deii.cefetmg.b [Centro Federal de Educacao Tecnologica (DEM/CEFET/MG), Belo Horizonte, MG (Brazil). Dept. de Engenharia de Materiais; Laguardia-Nascimento, Mateus; Barbosa-Stancioli, Edel F. [Universidade Federal de Minas Gerais (ICB/UFMG), Belo Horizonte (Brazil). Inst. de Ciencias Biologicas. Dept. de Microbiologia; Mansur, Herman S., E-mail: hmansur@demet.ufmg.b [Universidade Federal de Minas Gerais (DEM/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Metalurgica

    2009-07-01

    Chitosan/PVA based films were chemically crosslinked by glutaraldehyde (GA) in order to achieve scaffolds for potential tissue engineering application. Both precursors and developed films were characterized by FTIR and XRD in order to determine the presence of chemicals groups and nanostructural order, respectively. The results have showed that the GA crosslinking have altered the crystallinity of the chitosan and the increase on the C=N bands and decreasing of NH{sub 2} bands suggest that Chitosan/GA crosslinking has preference to occur in the carbon 2 by Schiff's base. The mechanical properties, swelling behavior, degradation rate in vitro and cellular viability were compatible with the characteristic of an epithelial tissue. The material presented a toughness range from 1.4 to 34MJ/m3, swelling from 150% to 700% in 24h, degradation rate from 20% to 75% (wt%) in 24h and cellular viability in vitro above 60% compared to the cellular control. The developed scaffolds from the films have also showed swelling and degradation in vitro properties well-matched for biomedical applications in tissue engineering (author)

  5. Transient behaviour of an adsorption refrigerator. Experimental study of the alcohol/activated carbon system; Comportement transitoire d`une machine frigorifique a absorption. Etude experimentale du systeme alcool / charbon actif

    Energy Technology Data Exchange (ETDEWEB)

    Luo, L. [Centre National de la Recherche Scientifique (CNRS), 54 - Nancy (France). Lab. des sciences du genie chimique; Feidt, M. [Nancy-1 Univ., 54 - Vandoeuvre-les-Nancy (France)

    1997-03-01

    The objective of this article is to present an experimental study of an adsorption refrigerator, accounting for the transient phenomena in each component of the machine, in particular in the adsorber. The couples adsorbate/adsorbent investigated (activated carbon/methanol or ethanol) have been chosen on the basis of an earlier comparative study. We have performed a full series of experiments to investigate the transient evolution of temperatures, pressures and the cycled mass, in a discontinuous cycle, and along the components of the refrigerating machine. The influence of various parameters is studies by varying one at a time: adsorbate/ adsorbent couple, alcohol load in adsorber, alcohol flowrate, heating power, initial desorption temperature. All these experimental observation are discussed and compared to transient models developed in a separate article. (authors) 12 refs.

  6. Effect of chitosan content on morphology and thermal properties of poly (vinyl alcohol) / chitosan blends; Eefeito do teor de quitosana na morfologia e propriedades termicas das blendas de poli (alcool vinilico) / quitosana

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Barbara Fernanda F. dos; Silva, Jessica Raquel M.B. da; Leite, Itamara Farias, E-mail: itamaraf@gmail.com [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Centro de Tecnologia. Departamento de Engenharia de Materiais

    2015-07-01

    The objective of this work consists in the preparation and characterization of blends consisting of biodegradable polymers, chitosan (CS) and poly (vinyl alcohol) (PVA), to evaluate the effect of different chitosan content in morphology and thermal properties of PVA blends/CS, prepared by the solution method. Therefore, the blends were characterized by Infrared Spectroscopy Fourier Transform (FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG). The results showed a good degree of interaction between the polymers of the blend constituents, suggesting certain degree of miscibility in the mixture. It was observed by XRD, that as the chitosan content in the mixture decreases PVA/CS, there is a slight increase in crystallinity. In comparative analysis, is observed that the composition PVA1/CS1 was the composition that showed improvement in thermal stability. (author)

  7. Sweet future? Brazil's ethanol fuel programme

    International Nuclear Information System (INIS)

    Calle, F.R.

    1999-01-01

    This article traces the history of Brazil's ethanol fuel programme from 1975 to the present, and considers Brazil's energy policy, and the implications of price liberalisation and privatisation aimed at reducing prices to control inflation. The achievements of ProAlcool which was established in 1975 with the aim of replacing petrol with ethanol, costs and investment in ProAlcool, environmental implications, and policy initiatives to boost ProAlcool are examined. Details of typical emissions from a 6-year old car in Brazil are tabulated illustrating the reduced emissions due to ethanol fuels

  8. L’exposition prolongée des consommateurs à un nouveau produit permet-elle d’accroître son adoption ?

    OpenAIRE

    Masson, Josselin; Aurier, Philippe; D'hauteville, François

    2010-01-01

    Cette recherche évalue l’effet de la consommation à domicile d’un nouveau produit (le vin à teneur réduite en alcool) sur son acceptabilité à long terme par les consommateurs, et suppose que l’exposition au produit et l’information non-sensorielle influenceront leurs évaluations hédoniques. Deux groupes de consommateurs ont alors été exposés soit à un vin normal, soit à un vin à teneur réduite en alcool, en condition aveugle le premier mois puis avec l’indication de leurs teneurs en alcool le...

  9. Environmental impacts of Proalcool: production and consumption

    International Nuclear Information System (INIS)

    Magrini, A.; Nassi, C.D.; Barcellos, P.P.

    1992-01-01

    The environmental impacts caused by the Programa Nacional do Alcool -PROALCOOL - Brazil, are analysed. Rio de Janeiro and Sao Paulo States are studied, comparing the regional differences. The production and the consumption phases are analysed separately. (L.J.C.)

  10. Implicaciones en la Comercializacion de Derivados no Financieros en el Sector Agricola de la Región Costa del Ecuador.

    OpenAIRE

    Espol; Suarez Torres, Soraya Johanna

    2017-01-01

    Las diferentes vicisitudes que tienen los agricultores en éste sector, tales como la falta de crédito, la escasa preparación, la volatilidad en los precios y el poco uso de la tecnología. Además de enlistar las principales ciudades costeras que se dedican a la producción agrícola. se revisará las funciones de las bolsas de valores ecuatoriana y los títulos-valores que se negocian, con el objetivo de ver si en algún momento ofertaron dichos servicios, a más de analizar las posibles razones por...

  11. Goods and services from the activities of the Constituyentes Atomic Center; Bienes y servicios derivados de actividades desarrolladas en el Centro Atomico Constituyentes

    Energy Technology Data Exchange (ETDEWEB)

    Hermida, Jorge D [Comision Nacional de Energia Atomica, General San Martin (Argentina). Centro Atomico Constituyentes

    2001-07-01

    Technologies developed and used at the Constituyentes Atomic Center (CAC) are applied in Argentina in different fields, such as seamless pipes industry, non-destructive testing and quality assurance, food industry, microalloyed steels, medicine, space activities, air pollution studies, etc. The CAC has also a wide program of technical assistance to the industry.

  12. ÓXIDOS METÁLICOS DERIVADOS DE MATERIAIS TIPO HIDROTALCITAS CONTENDO Ga3+ COMO CATALISADORES PARA SÍNTESE DE BIODIESEL ETÍLICO

    Directory of Open Access Journals (Sweden)

    Marcelo Mancini

    Full Text Available Summary: The synthesis of like-hydrotalcites materials (layered double hydroxides - LDHs with molecular formula MgxM3+y(CO3(OH16·4H2O in different ratios Mg2+/M3+ where M3+ is Al3+, Ga3+ or both was carried out by the coprecipitation method to be applied in the transesterification reactions for synthesis of ethyl biodiesel from soybean oil and ethanol. The reactions were processed for 12 hours at 120 ºC at a molar ratio oil/ethanol (1/20 with 20% (m/m of the catalyst in relation to the oil mass, and the products were quantified by GC-FID. With the introduction of Ga3+ in the solid, some physicochemical characteristics of LDHs were kept based in the data from X-ray pattern diffraction (XRD, vibrational spectrometry (ATR-FTIR, and scanning electron microscopy (SEM, but changes from thermogravimetric analysis (TGA, superficial area (BET, and the acidity/basicity properties were observed. Typical hydrotalcite with Mg2+/M3+ = 3 was used as reference material and reach 45.1% of biodiesel conversion. Although the best conversion result (77.6% was reached from the solid without Ga3+ and with Mg2+/M3+ ratio 4/1, there is an interesting correlation between the catalytic activities and the physicochemical properties of the solids with Ga3+ and their respective homologous materials as discussed in this work.

  13. Myrsinoic A acid and its derivative: in vitro inhibitors of photosynthesis; Acido myrsinoico A e derivado: inibidores da fotossintese in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Marcela Carmen de M.; Oliveira, Gracielle S. de; Menezes, Antonio Carlos S [Universidade Estadual de Goias, Anapolis, GO (Brazil). Unidade Universitaria de Ciencias Exatas e Tecnologicas; Vieira, Paulo Cezar; Silva, Maria Fatima das G.F. da [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Quimica; Veiga, Thiago A.M., E-mail: tveiga@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Inst. de Ciencias Ambientais, Quimicas e Farmaceuticas. Dept. de Ciencias Exatas e da Terra

    2012-07-01

    Myrsinoic A acid, isolated from Myrsine cuneifolia and its hydrogenated derivative had their effect on photosynthesis tested. The compounds inhibited the electron flow (basal, phosphorylating and uncoupled) from water to methyl viologen; therefore, they act as Hill reaction inhibitors in spinach thylakoids. They inhibited partial reactions of PSII electron flow from water to 2,5-dichloro-1,4-benzoquinone, from water to sodium silicomolybdate, and partially electron flow from diphenylcarbazide to 2,6-dichloroindophenol. Their inhibition sites were at the donor and acceptor sides of PSII, between P{sub 680} and Q{sub A}. Chlorophyll {alpha} fluorescence measurements confirmed the behavior of the compounds (pool of quinones). (author)

  14. Química e mineralogia de solos derivados de rochas do Grupo Bambuí no norte de Minas Gerais

    Directory of Open Access Journals (Sweden)

    C. V. Oliveira

    1998-12-01

    Full Text Available Perfis de solos representativos do Distrito Agroindustrial do Jaíba, norte de Minas Gerais, foram descritos morfologicamente, tendo sido suas amostras coletadas e analisadas química, física e mineralogicamente, com o fim de obter informações que contribuam para sua melhor exploração agrícola. Embora provenientes, em sua quase totalidade, de calcário do grupo Bambuí, e com aparente homogeneidade fisiográfica (relevo plano e floresta caducifólia, os solos apresentaram grande diversidade nesses aspectos. Mineralogicamente, observaram-se a ilita e a caulinita como minerais comuns, esta última presente mesmo em Vertissolo e Rendzina, solos com expressiva quantidade de carbonatos livres. A presença de esmectita no Vertissolo, na Rendzina e no Cambissolo de argila de atividade alta indica que a escassez de chuva, a riqueza do material de origem e sua superficialidade em topografia plana dificultam a saída de sílica e bases do sistema, favorecendo a formação de esmectita. Tal mineralogia, associada à sazonalidade climática, parece responsável pelo fendilhamento expressivo desses solos no período seco. Os solos apresentam cores variadas: solos vermelhos e vermelho-amarelados, graças à presença de hematita e goethita, referem-se principalmente aos Latossolos situados em posições ligeiramente mais elevadas na paisagem, dispondo de melhor drenagem; amarelos e bruno-amarelados, normalmente situados em áreas mais deprimidas, que, aliados à superficialidade e massividade do material de origem, restringem a drenagem, favorecendo a gênese da goethita e levando à formação de concreções ferro-manganosas em quantidades expressivas; nestes ambientes, foram constatados Cambissolos de argila de atividade alta (Ta e baixa (Tb, Vertissolos ou solos com características vérticas, também brunados, e Rendzina. A baixa relação Fe o/Fe d (ferro oxalato/ferro ditionito revelou predomínio de óxidos mais cristalinos. Os solos eutróficos e epieutróficos (distróficos ou álicos, com baixos teores de Na e relevo dominantemente plano e suave-ondulado, confirmam a grande potencialidade agrícola da área, sobretudo sob irrigação. A diversidadade das características químicas, físicas e mineralógicas dos solos, entretanto, aponta variações de comportamento frente ao uso agrícola, indicando adequações diferenciadas de práticas de manejo.

  15. Balanço geoquímico de solos derivados de rochas básico-ultrabásicas no ambiente subtropical do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    L. F. S. Pinto

    1997-12-01

    Full Text Available O balanço de massa da intemperização de solos desenvolvidos de rochas básico-ultrabásicas no Rio Grande do Sul, os menos intemperizados constatados até o presente no estado, mostrou nos horizontes superficiais uma concentração relativa mais elevada dos elementos móveis do que nos subsuperficiais, indicando a existência de descontinuidade entre eles. Tais feições, em conjunto com a mineralogia e com a morfologia dos perfis investigados, indicam a ocorrência de eventos erosivo-deposicionais em um passado pedogeneticamente recente, bem como uma contribuição importante de materiais intempericamente menos evoluídos para a composição mineral dos horizontes superficiais. Esses eventos erosivos e o rejuvenescimento superficial dos perfis explicam o pouco desenvolvimento e a semelhança química e mineralógica desses solos com os desenvolvidos de rochas básico-ultrabásicas em regiões temperadas.

  16. Riesgos a la salud humana e impactos ambientales derivados del manejo integral de residuos hospitalarios en el hospital infantil Napoleón Franco Pareja

    OpenAIRE

    Lugo Silva, Kelly Beth de Jesús; SENA

    2016-01-01

    Desde el año 2000, el manejo adecuado de residuos hospitalarios ha adquirido una notable importancia en Cartagena, dado que solo el 9 % de los centros médicos y hospitalarios de la ciudad les da un tratamiento correcto. Los residuos hospitalarios representan un riesgo para la salud del personal médico, paramédico y de enfermería, así como de pacientes, visitantes, personal de recolección de residuos y comunidad en general, además del riesgo ambiental que de ellos se deriva. Este artículo es u...

  17. El desarrollo profesional docente derivado de la aplicación de los Proyectos de Trabajo en un aula infantil. Un estudio de caso

    Directory of Open Access Journals (Sweden)

    María del Carmen RUIZ TORRES

    2016-05-01

    Full Text Available Este artículo presenta una etnografía desarrollada en un aula infantil a través de un estudio de caso. Se trata de una investigación cualitativa que focaliza su indagación en la capacidad de los Proyectos de Trabajo para contribuir al desarrollo profesional de la docente. Se analiza si el rol que la docente adopta al trabajar por Proyectos de Trabajo facilita su desarrollo profesional en tanto en cuanto le ayuda a mejorar las estrategias de atención a la diversidad del alumnado y sus familias. Los resultados obtenidos arrojan los sentimientos de incertidumbre que experimenta la docente y sus dificultades para transitar desde la metodología tradicional hasta la implantación de Proyectos de Trabajo. Se muestra el tránsito desde un rol docente directivo hasta la asunción de un papel de acompañante en el aprendizaje del alumnado. Finalmente se identifican algunas resistencias en la cultura del centro que ralentizan la implantación de este método tanto en el aula, como su transferencia al resto de etapas del centro

  18. Production of biosurfactants for environment remediation contaminated with oil and derivatives; Producao de biossurfactantes para remediacao de ambiente contaminados com petroleo e derivados

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Adriano Henrique Soares de; Guimaraes, Juliana Aguilar; Hiluy Filho, Joao Jose; Lopes, Ada Amelia Sanders [Universidade Federal do Ceara, Fortaleza, CE (Brazil). Dept. de Engenharia Quimica]. E-mail: hiluy@ufc.br

    2003-07-01

    Biosurfactants are emulsifiers of hydrocarbons produced by bacteria, yeast and fungi. They are polymers that form micelles and stay at the interface between liquid of different polarities. This work aim to study the development of the biosurfactant production process and its application related to oil sludge. This research has been done in three different steps: the Acinetobacter iwoffii inoculation, its growth in a nutritive broth and the fermentation under specific conditions. It was used three different kind of substrates: ethanol, glycerol and kerosene for comparison. The surfactant potential was evaluated by the emulsification indexes with suspension biomass and efficiency tests with oil sludge. Preliminary results show that biosurfactant production by Acinetobacter iwoffii can be a feasible process due to the satisfactory emulsification indexes that have been obtained. (author)

  19. Vermicomposting as alternative for recycling the sludges of paper industry; El vermicompostaje como alternativa para el reciclaje de lodos residuales derivados de la industria papelera

    Energy Technology Data Exchange (ETDEWEB)

    Elvira, C.; Sampedro, L.; Mato, S. [Departamento Recusros Naturales, Medio Ambiente, Universidad de Vigo, Vigo (Spain); Nogales, R. [U.E.I. Agroecologia y Proteccion Vegetal, Granada (Spain)

    1995-12-01

    Vermicomposting is a process of bio oxidation and stabilization of organic materials involving the joint action of earthworms and microorganisms, by which high-quality organic fertilizers called vermicomposts are ob tamed. Waste sludge from the pulp-paper and paper industry may be converted using vermicomposting techniques which require correct conditioning of the waste. Earthworms speed up the biodegradation and humification processes of these soil sludges. Vermicomposts are obtained which could be used as organic amendments or fertilizers in agriculture and forestry.

  20. Molecular markers derived from bombesin for tumor diagnosis by SPECT and PET; Marcadores moleculares derivados da bombesina para diagnostico de tumores por SPECT e PET

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, Priscilla Brunelli

    2012-07-01

    A high number of molecules have already been identified to have high affinity to some receptors overexpressed on tumour cells and the radiolabelling of those molecules offers the possibility of new compounds for tumour diagnosis and therapy by nuclear medicine. Among of those molecules, bombesin (BBN) has become focus of interest, as its BB{sub 2} receptors are known to be overexpressed in prostate, breast, colon, pancreatic and lung tumour, as long as glioblastomas and neuroblastomas. BBN agonists and antagonists have already been described for this purpose and promising results were obtained in preclinical studies. However, most of them exhibited high abdominal accumulation, especially in pancreas and intestines, which can compromise diagnosis accuracy and cause serious adverse effects in therapy. In this context, the goal of the present work to radiolabel new BBN derivatives with {sup 11}1In and {sup 68}Ga and to evaluate their potential for BB{sub 2} positive tumors diagnosis by single photon emission tomography (SPECT) and positron emission tomography (PET). The structure of studied peptides was Q-YG{sub n}-BBN(6-14), where Q is the chelator, n is the number of glycine aminoacids in the spacer YG{sub n} and BBN(6-14) is the original bombesin sequence from the aminoacid 6 to 14. The derivative in which the last aminoacid (methionine, Met) was replaced by norleucine (Nle) was also evaluated. The experimental evaluation of the bombesin derivatives was divided into four steps: computational studies, molecular markers for SPECT, molecular markers for PET and toxicological studies. The theoretical partition (log P) and distribution (log D) coefficients were calculated for all bombesin derivatives conjugated to DTPA (diethylenetriaminepentaacetic acid) and DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) chelators applying computational programmes. Bombesin derivatives for SPECT were developed by radiolabelling DTPA-conjugated bombesin derivatives with {sup 111}In to determine the best spacer for in vivo applications, regarding the stability and in vivo properties. The derivative with the most favorable properties and conjugated to DTPA or DOTA was evaluated in comparative in vitro and in vivo studies in different BB{sub 2} expressing tumour cells, in order to determine the best chelator to be used in vivo. Some comparative studies were also performed with the BBN analogue BZH3, which was described by the literature. The molecular marker for PET was developed by radiolabelling the derivative chosen with {sup 68}Ga and evaluating the biodistribution profile in healthy and tumour mice. Finally, toxicological studies were performed by injecting an excess of cold bombesin derivatives in rats to determine their safety for clinical queries. All derivatives conjugated to DTPA were radiolabelled with {sup 111}In at high radiochemical purity and high specific activity (174 GBq/{mu}mol). The molecular markers presented high stability during radiolabelling and low stability at room temperature and this stability was increased after the addition of stabilizer agents. Stability in human serum analysis suggested time-course degradation by human serum enzymes and the increase on glycine aminoacids in the spacer improved the molecular markers stability, as long as the replacement of terminal Met by Nle. HPLC and log P results confirmed the theoretical log P data which showed that the BBN derivatives present low lipophilicity, which decreases with the increase on glycine aminoacids in the spacer and the replacement of terminal Met by Nle. In vivo studies demonstrated that {sup 111}In-DTPA-BBN analogues present fast blood clearance, excretion by renal pathway and low abdominal accumulation. Highest tumour uptake was observed with the Nle-terminal derivative (YG{sub 5}N), which was used for the comparison between the DTPA and DOTA chelators. DOTA-YG{sub 5}N was also radiolabeled with {sup 111}In at high specific activity (100 GBq/{mu}mol), but this was lower than for the DTPA derivatives. Saturation binding assays on prostate (PC-3 e LNCaP) and breast (T-47D) tumour cells showed similar affinity for the radiopeptide conjugated to DTPA and DOTA, higher binding of DOTA-peptide to PC-3 and LNCap cells was observed, but not for T-47D cells. This molecular marker was also more internalized by PC-3 cells. In vivo studies showed higher stability for {sup 111}In-DOTA-YG{sub 5}N in mice serum, and the uptake of DTPA and DOTA peptide was similar by PC-3 and LNCaP tumour, although this last tumour has shown 2-fold less BB2 receptors than PC-3. SPECT/CT imaging of PC-3 and LNCaP was possible with both radiopeptides. When compared to {sup 111}In-BZH3, the molecular markers present similar tumour uptake, but with more favorable images, because of their lower abdominal uptake. DOTA-YG{sub 5}N was radiolabeled with {sup 68}Ga with high radiochemical purity and the biodistribution profile was similar to the peptide labeled with {sup 111}In, with significative PC-3 tumour uptake. Toxicological studies showed the bombesin derivatives are safe up to concentration administered and did not present hematological, hepatic or renal toxicity. The BBN derivative YG{sub 5}N conjugated to DTPA or DOTA is a promising and safe tool for BB{sub 2} expressing tumour diagnosis by SPECT and PET. (author)

  1. Brote de poliomielitis en Haití y la República Dominicana debido a un virus derivado de la vacuna antipoliomielítica oral

    Directory of Open Access Journals (Sweden)

    Landaverde Mauricio

    2001-01-01

    Full Text Available In October 2000, the Ministries of Health of the Dominican Republic and Haiti notified two cases of acute flaccid paralysis (AFP in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occurred in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the Centers for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV, but with 3% genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5% genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0%. Thus, the 3% genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas.

  2. Composición, caracterización y potencial aterogénico de aceites, grasas y otros derivados producidos o comercializados en Costa Rica

    OpenAIRE

    Monserrat Castro-Bolaños; Carlos H Herrera-Ramírez; Giselle Lutz-Cruz

    2005-01-01

    Las enfermedades cardiovasculares, tan comunes entre los costarricenses, están relacionadas con la ingesta de altas cantidades de lípidos capaces de ejercer una acción perjudicial en las arterias del cuerpo humano. El presente estudio tuvo como objetivo determinar la calidad de las grasas y aceites más consumidos por la población de nuestro país. Se recolectaron y codificaron 15 marcas diferentes de mantequillas o margarinas (A, B, D1 a D11), 7 tipos de mantecas (E1 a E7) y 14 marcas diferent...

  3. Synthesis and preliminary evaluation of N-acylhydrazone compounds as antibacterial and antifungal agents; Sintese e avaliacao preliminar da atividade antibacteriana e antifungica de derivados N-acilidrazonicos

    Energy Technology Data Exchange (ETDEWEB)

    Cachiba, Thomas Haruo; Carvalho, Bruno Demartini; Carvalho, Diogo Teixeira [Universidade Federal de Alfenas, MG (Brazil). Fac. de Ciencias Farmaceuticas. Dept. de Alimentos e Medicamentos; Cusinato, Marina; Prado, Clara Gaviao; Dias, Amanda Latercia Tranches, E-mail: diogo.carvalho@unifal-mg.edu.br [Universidade Federal de Alfenas, MG (Brazil). Inst. de Ciencias Biomedicas

    2012-07-01

    We describe the synthesis and evaluation of N-acylhydrazone compounds bearing different electron-donating groups in one of its aromatic rings, obtained using a four-step synthetic route. IC{sub 50} values against pathogenic fungi and bacteria were determined by serial microdilution. Compounds showed low activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. By contrast, a derivative with a meta-oriented electron-donating group showed significant activity (IC50) against Candida albicans (17 {mu}M), C. krusei (34 {mu}M) and C. tropicalis (17 {mu}M). Results suggest this is a promising lead-compound for synthesis of potent antifungal agents. (author)

  4. Nuevos receptores heteroditópicos derivados de urea con potencial aplicación en el reconocimiento selectivo de aniones y metabolitos fosfatados

    OpenAIRE

    Carreira Barral, Israel

    2016-01-01

    [Resumen]En la presente Tesis Doctoral se han desarrollado nuevas plataformas estructurales basadas en complejos de metales del bloque d (CoII, NiII, CuII y ZnII) con potencial aplicación en el reconocimiento selectivo de aniones y metabolitos con actividad biológica. Los sistemas diseñados se pueden clasificar como receptores heteroditópicos que incorporan, por un lado, una zona de reconocimiento catiónico [1,7-dioxa-4,10-diazaciclododecano, 1,4,7,10-tetraazaciclododecano (...

  5. Influence of organic matter and clay minerals in migration of derivative compounds of hydrocarbons; Influencia da materia organica e argilominerais na migracao de compostos derivados de hidrocarbonetos

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Denize Gloria Barcellos; Mendonca Filho, Joao Graciano de; Polivanov, Helena [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Geociencias. Dept. de Geologia]. E-mail: denize@geologia.ufrj.br; graciano@geologia.ufrj.br; helena@acd.ufrj.br

    2003-07-01

    Soil samples from the Guanabara Bay in Duque de Caxias city (RJ) were submitted to mineralogical and organic geochemistry analyses. This proceeding was used mainly to determine a possible interaction of hydrocarbons contaminants with the organic matter and the clay minerals presents in this mangrove. The sampling was carried out using Direct Push techniques. Thus, the mainly clay minerals characterizes were: gibbsite, illite, caulinite and smectite. The compositional analysis of organic constituents showed a predominance of amorphous material (degraded cuticles), followed of wood material and sporomorphs constituents, suggesting that the biological degradation occurred in situ. (author)

  6. Emulsification index of petroleum products by bacteria isolated from mangrove; Taxa de emulsificacao de derivados do petroleo por bacterias isoladas de mangue

    Energy Technology Data Exchange (ETDEWEB)

    Krepsky, Natascha; Queiroz, Fernanda; Barcelos, Mabel Araujo de; Fontana, Luis Francisco; Bittencourt, Jose Augusto Pires; Pimenta, Alessandro L.; Silva, Frederico Sobrinho da; Bispo, Maria das Gracas Silveira; Crapez, Mirian Araujo Carlos [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Programa de Pos-graduacao em Biologia Marinha]. E-mail: mirian@vm.uff.br

    2003-07-01

    Oil spillage during ship transportation or at gas stations may be deleterious to environment due to its affinity for organic matter and its prompt distribution over the ground water surface, limiting bioremediation. The usage of bacterial surfactants can enhance the removal of petroleum hydrocarbons from the impacted area. Thus, the study of bacterial emulsification is relevant for improved environmental decontamination programs. Three Bacillus spp. were isolated from mangrove sediment of APA de Guapimirim -RJ, a protection area previously impacted with petroleum hydrocarbon. Emulsification index was quantified from gasoline, kerosene and Arabian light. The bacteria showed a high emulsification index, especially for gasoline, that seemed to be related to its biomass. Our results indicated a possible utilization of this biosurfactant in the environmental remediation on areas impacted with gasoline or Arabian light. (author)

  7. Desenvolvimento de filmes biodegradaveis a partir de derivados do grão de quinoa (Chenopodium quinoia Willdenow) da variedade "Real"

    OpenAIRE

    Patricia Cecilia Araujo Farro

    2008-01-01

    Resumo: O grão de quinoa (Chenopodium quinoa, Willdenow) é um pseudocereal originário da América do Sul Andina, que tem gerado interesse industrial crescente e cultivo diversificado em diversos países de América do Norte e da Europa. Recentemente nos países da América Latina tem-se despertado um interesse comum na busca de tecnologias de desenvolvimento de biomateriais, como uma forma de diminuir a poluição gerada pelos resíduos sintéticos, utilizando os recursos naturais próprios da região. ...

  8. Cultivo de células de piel humana sobre un soporte polimérico artificial y un soporte acelular derivado de vejiga porcina

    Directory of Open Access Journals (Sweden)

    Alejandro Astúa

    2015-05-01

    Full Text Available La ingeniería de tejidos aplicada a lesiones de la piel propone constantemente métodos innovadores con el propósito de mejorar la calidad de vida de las personas con estas patologías. El objetivo de este estudio fue cultivar fibroblastos y queratinocitos humanos sobre soportes artificiales poliméricos termosensibles y membranas acelulares derivadas de vejiga porcina. Se establecieron cultivos primarios y subcultivos y, subsecuentemente, se obtuvieron epidermis diferenciadas y estratificadas a partir de queratinocitos que crecieron en cocultivo con una capa alimentadora (feeder layer de fibroblastos dérmicos humanos. Mediante microscopía óptica, se efectuaron observaciones relacionadas con el crecimiento y la diferenciación de ambos tipos celulares. Se encontró que las células epiteliales cultivadas sobre soportes termosensibles produjeron láminas epidérmicas bastante semejantes a una epidermis natural, mientras que la membrana acelular derivada de vejiga porcina resultó menos exitosa para el desarrollo de queratinocitos.

  9. Ácido linoleico conjugado en leche de oveja y productos derivados: presencia e influencia del proceso tecnológico

    OpenAIRE

    Rodríguez Castañedas, José Luis

    2012-01-01

    [ES] El objetivo general de este trabajo es conocer el contenido de isómeros del Ácido Linoleico Conjugado (CLA) en leche de oveja parcialmente desnatada y tratada térmicamente, así como en yogur y cuajada elaborados con leche de la misma especie animal. Hasta el momento, no existen datos en productos españoles destinados al consumo. Para alcanzar el objetivo general, se han planteado tres objetivos parciales que se exponen a continuación: 1)Puesta a punto de un método que permita la cuan...

  10. Scheduling optimization of a real-world multi product pipeline network; Otimizacao das operacoes de transporte de derivados de petroleo em redes de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Boschetto, Suelen N.; Felizari, Luiz C.; Magatao, Leandro; Stebel, Sergio L.; Neves Junior, Flavio; Lueders, Ricardo; Arruda, Lucia V.R. de [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Ribas, Paulo Cesar; Bernardo, Luiz F.J. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    This work develops an optimization structure to aid the operational decision-making of scheduling activities in a real world pipeline network. The proposed approach is based on a decomposition method to address complex problems with high computational burden. The Pre-analysis makes a previous evaluation of a batch sequencing, getting information to be entered into optimization block. The continuous time Mixed Integer Linear Program (MILP) model gets such information and calculates the scheduling. The models are applied to a pipeline network that connects different areas including refineries, terminals, and final clients. Many oil derivatives (e.g. gasoline, liquefied petroleum gas, naphtha) can be sent or received in this network. The computational burden to determine a short-term scheduling within the considered scenario is a relevant issue. Many insights have been derived from the obtained solutions, which are given in a reduced computational time for oil industrial-size scenarios. (author)

  11. Problemas derivados de la indeterminación legal de la profesión habitual: situaciones de compatibilidad no deseadas y propuestas de revisión

    Directory of Open Access Journals (Sweden)

    Ana Álvarez Moreno

    Full Text Available La determinación de la profesión habitual se configura como una de las piezas clave del sistema por el que se rige la declaración de invalidez permanente. Lo es porque determina tanto la procedencia de la declaración inicial de la invalidez, de manera fundamental en la incapacidad permanente total, como la compatibilidad de la misma una vez reconocida con el trabajo, con un salario o con una posible prestación futura derivada del mismo. La indeterminación legal de los parámetros que configuran el reconocimiento de una situación de invalidez deriva, en situaciones de compatibilidad difíciles de justificar. Sin duda la más sorprendente es la prácticamente absoluta compatibilidad de la situación de incapacidad permanente absoluta y de gran invalidez con el trabajo, según la doctrina configurada por el Tribunal Supremo. También hay dificultad para revisar el grado de incapacidad reconocido, puesto que la misma ha de ajustarse a los motivos tasados por el legislador. Conclusiones: - Delimitar el concepto de profesión habitual de una forma de manera que se amplíe desde el marco reducido de las funciones al más amplio del grupo profesional o, cuando menos, al que habilita al empresario para efectuar la movilidad funcional. - Modificar las actuales causas de revisión de la invalidez posibilitando que la mejoría también pueda ser considerada desde la perspectiva profesional, bien por la adaptación y rehabilitación funcional posterior o bien porque las modificaciones de los procesos productivos modifiquen la capacidad profesional inicialmente determinada. - Determinar en supuestos de nuevo trabajo si es compatible con las limitaciones funcionales objetivadas e impedir así el desempeño de trabajos con requerimientos similares o superiores a los que provocaron el reconocimiento de la situación de IPT. - Suspender la pensión de IPT en el supuesto de que el beneficiario de la misma simultaneé su percibo con el desempeño de la misma profesión, o funciones, o de otras que exijan los mismos requerimientos que aquella para la que fue declarado inválido. - Vincular la declaración de IPT a planes de formación para la búsqueda de empleo y rehabilitación ocupacional, asociando el percibo de la prestación por IPT a la búsqueda activa de empleo mediante la obligatoriedad de participar en programas de formación destinados a facilitar la reincorporación a la vida laboral activa. - Valoración de la incidencia de la edad y la formación en el reconocimiento de las situaciones de incapacidad permanente. - Profundizar en el análisis del paralelismo o correlación entre las prestaciones de desempleo y de IPT.

  12. Criterio de selección de un árbol óptimo según coeficientes de asociación derivados de χ²

    OpenAIRE

    Cano Sevilla, Francisco J.; Munduate del Río, Arantza; Pérez Prados, Antonio

    1996-01-01

    Se analiza en primer lugar la variación que se produce en el valor del coeficiente de contingencia al realizarse un proceso de poda en un árbol de decisión T. Conocido este efecto, se define una cantidad criterio que combina linealmente el coeficiente de contingencia con el índice de simplicidad. A partir de esta cantidad criterio, se propone un método de obtención de un árbol óptimo para cada uno de los distintos valores del parámetro α de la combinación lineal. Para seleccionar el árbol ópt...

  13. Criterio de selección de un árbol óptimo según coeficientes de asociación derivados de 2

    OpenAIRE

    Cano Sevilla, F. J.; Munduate del Río, A.; Pérez Prados, A.

    1996-01-01

    Se analiza en primer lugar la variación que se produce en el valor del coeficiente de contingencia al realizarse un proceso de poda en un árbol de decisión T. Conocido este efecto, se define una cantidad criterio que combina linealmente el coeficiente de contingencia con el índice de simplicidad. A partir de esta cantidad criterio, se propone un método de obtención de un árbol óptimo para cada uno de los distintos valores del parámetro α de la combinación lineal. Para seleccionar el árbol ópt...

  14. Diseño de una estrategía de cobertura de fluctuación de precios de un Commodity mediante el uso de derivados financieros.

    OpenAIRE

    Alvarado Rodríguez, Yuri Rocío

    2015-01-01

    La interacción que actualmente se da en los mercados internacionales se caracteriza por factores como: la variación de los precios de los bienes y servicios, la volatilidad de las tasas de cambio, la fluctuación de las tasas de interés, los cuales tienen un impacto en la vida de las personas, las empresas e inclusive los países. Está situación de incertidumbre repercute en las operaciones que estén relacionadas con ellos en el sector real, mismas que pueden ser comerciales, productivas o cred...

  15. Análisis del mercado de productos derivados de créditos/acciones antes y durante la Gran Recesión

    OpenAIRE

    Frigola Alcalde, Hector

    2010-01-01

    La crisis que empezó el año 2007 se ha convertido en la mayor recesión desde la Gran Depresión de los años 1930, una crisis que muchos especialistas han bautizado con el nombre de Gran Recesión. Este trabajo estudia las causas que han llevado al mercado de capital a semejante colapso global, analizando tres aspectos clave en el desarrollo de la crisis: los Credit Default Swaps (CDS), la titularización y las estrategias de un hedge fund, Topaz, que utilizaba un modelo cuantitativo para la valo...

  16. Concentração espacial e desenvolvimento local: cadeia produtiva de couro e derivados do Estado do Pará

    Directory of Open Access Journals (Sweden)

    Dilamar Dallemole

    2008-01-01

    for after that considering all was esteem the supply chain. Was identified as pecialized region located in the Mesorregião Sudeste Paraense, composed for 16 cities that had reached the minimum score considered by the related methodology.

  17. Diagnóstico das condições de processamento de produtos artesanais derivados do leite no estado de Sergipe

    Directory of Open Access Journals (Sweden)

    Joanna S. Santos

    2008-08-01

    Full Text Available O presente trabalho teve como finalidade a realização do diagnóstico dos queijos de coalho, de manteiga e pré-cozido comercializados e amplamente consumidos no estado de Sergipe. Verificou-se as condições de processamento e de venda, a caracterização físico-química e a qualidade microbiológica. Foram analisadas 81 amostras, 27 para cada tipo de queijo, provenientes de dez municípios selecionados (Aracaju, Nossa Senhora da Glória, Macambira, Itabaiana, Carira, Estância, Simão Dias, Poço Redondo, Nossa Senhora do Socorro e Frei Paulo, adquiridos através de pontos comerciais. Os parâmetros físico-químicos analisados mostraram que os queijos de coalho, de manteiga e pré-cozido, produzidos em Sergipe, apresentaram, em sua maioria, valores coerentes com os parâmetros estabelecidos pela legislação vigente. Entretanto, o parâmetro amido apresentou irregularidade no quadro geral da cadeia produtiva de queijo de manteiga, confirmando a necessidade de fiscalização deste produto a fim de se evitar possíveis adulterações. As análises microbiológicas evidenciaram que deve haver uma inspeção para a melhoria da higiene de todos os queijos estudados, já que apresentaram grande contaminação por coliformes fecais, bolores e leveduras, assim como bactérias aeróbias mesófilas. Os resultados obtidos demonstraram a necessidade de melhoria na cadeia produtiva dos queijos regionais comercializados no estado de Sergipe, para assim, oferecer um produto de qualidade à população sergipana, além de contribuir para a conquista de novos mercados.

  18. Principais Microrganismos envolvidos na deterioração das características sensoriais de derivados cárneos

    OpenAIRE

    Alcantara, Marcela de; Universidade Federal Rural do Rio de Janeiro; Morais, Isabela Cristina Lobo de; Universidade Federal Rural do Rio de Janeiro; Matos, Cyllene de; Universidade Federal Rural do Rio de Janeiro; Souza, Ornelas da Cunha Corrêa de; Universidade Federal Rural do Rio de Janeiro

    2013-01-01

    Os produtos cárneos são facilmente contaminados por microrganismos durante a manipulação e o processamento. Após ter sido contaminado, se o alimento oferecer condições para que os microrganismos se multipliquem, estes podem alterar as características físicas e químicas dos alimentos, podendo causar, assim, a sua deterioração. Os tipos de deterioração variam de acordo com as condições atmosféricas que envolvem os produtos e com a temperatura de armazenamento. Os principais microrganismos envol...

  19. Introducción y comercialización de la harina de malanga y sus derivados: tortillas y empanadas, en los mercados de Guayaquil y Quevedo

    OpenAIRE

    Almeida Andrade, Maria Fernanda; Chiang Guerra, Danixa; Zamora Maldonado, Pamela; Mejia Coronel, Marco Tulio

    2009-01-01

    This project was performed with the purpose of knowing the acceptance of a new product on the market mainly for the Ecuadorian canton of Guayaquil and Quevedo, where the question was being if Quevedo's market place where they have greater knowledge of that tuber, since it is one of the places where most malanga occurs on the contrary in the city Guayaquil is not well known but the existence of people who are willing to consume the finished product because of the nutrition it offer...

  20. Analysis of the energy consumed in the oil pumping and its products; Analise da energia consumida no bombeamento de petroleo e seus derivados

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Fabio Arbex [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Santiago, Adilson da Silva [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This work describes a computer application for monitoring the operation of a set of motor-pumps of a pipeline. It provides information for the analysis of the electrical and hydraulic variables of these equipment allowing a better control of the transference of fluids through the pipeline. It also makes possible knowing the consumption of energy and the power level used. It helps establishing optimal operation conditions and to generate efficiency indices for the control of the equipment. (author)

  1. Estudo do comportamento dos linfócitos derivados do timo em pacientes com pênfigo foliáceo na presença de levamisol

    Directory of Open Access Journals (Sweden)

    Maria Dolores Porto Acedo

    1984-03-01

    Full Text Available Foram estudados linfócitos T de pacientes portadores de pênfigo foliáceo em relação à sua capacidade de formar rosáceas "E'. diante de diferentes concentrações do imunopotenciador levamisol. O levamisol é uma substância que estimula formação de rosáceas de linfócitos T ativos em indivíduos normais. Os linfócitos de pacientes antes da corticoterapia sistêmica não responderam ao levamisol; já os linfócitos de pacientes em tratamento com corticóides tiveram inibida sua capacidade de formar rosáceas. Esses achados sugerem alteração no metabolismo celular dos linfócitos de pacientes penfigosos devido provavelmente a alguma falha no sistema enzimático dessas células envolvendo a fosfodiesterase do AMPc.T lymphocytes from patients with Pemphigus foliaceus were studied fortheir ability to form E rosettes in thepresence of different concentrations of the immunostimulant levamisole. Lymphocytes from patients before systemic corticotherapy did not show stimulation when incubated with levamisole. Lymphocytes from patients submitted to corticotherapy had their ability to form rosettes inhibited. Those data suggest that the lymphocytes from patients with Pemphigus foliaceus may have some kind of defect in the phosphodiesterase of cyclic AMP.

  2. Incremento de disolución de un derivado del furano mediante la técnica de secado por atomización

    Directory of Open Access Journals (Sweden)

    Antonio Iraizoz Barrios

    2012-06-01

    Full Text Available Objetivo: incrementar la solubilidad en agua del 2-bromo-5-(2-bromo-2-nitrovinyl-furano (G1, un ingrediente farmacéuticamente activo sintetizado por el Centro de Bioactivos Químicos de la Universidad Central de Las Villas, con potente acción bactericida y fungicida, mediante la elaboración de macropartículas de dispersiones sólidas utilizando un proceso de secado por atomización. Métodos: se realizó un ensayo preliminar de secado por atomización de la suspensión de G1, compuesta por: 10 g de G1, 1 g de Aerosil (Aerosil®, Degusa, Bélgica, 1 g de laurilsulfato de sodio y 100 mL de agua. La atomización se efectuó en un equipo de laboratorio (Buchi Mini Dryer spray a 90 ºC. La dispersión sólida obtenida fue caracterizada físico-químicamente mediante difracción de rayos X, granulometría láser por el método de difracción angular, calorimetría diferencial de barrido, microscopia electrónica de barrido y espectrofotometría de absorción infraroja. Resultados: las partículas obtenidas presentaron un pequeño tamaño, forma esférica y un incremento de la cristalinidad del G-1; no se encontraron interacciones entre los componentes de la dispersión ni presencia de productos de degradación, y la solubilidad del G-1 en agua resultó notablemente incrementada. Conclusiones: el producto obtenido por la técnica de secado por atomización incrementó apreciablemente la solubilidad del G1 sin afectar los grupos funcionales, responsables de la actividad terapéutica que se le reportan al ingrediente activo estudiado. Estos alentadores resultados sugieren la necesidad de continuar estudios para la optimización del proceso y realizar al producto obtenido ensayos de estabilidad con el objetivo de su futura inclusión en formas farmacéuticas de dosificación.

  3. EL ESPACIO UBICUO La idea de espacio arquitectónico derivado de la implementación de las tecnologías de Inteligencia Ambiental

    OpenAIRE

    Cerdá Pérez, Manuel

    2016-01-01

    [EN] This work is aimed to interpret, analyse and know which are the conceptual bases that nowadays define the idea of space in architecture, the contemporary ways of dwelling, through the analysis on a specific pattern, the ubiquitous space. This tries to reveal a new way to understand space, which has arisen from what today is shaped as "the new paradigm", associated to the Information and Communications Technology era (ICT). The intention of this work has been born with a proposing vi...

  4. Coal derivates for reduction of SO{sub 2} N0{sub x}; Derivados del Carbon para la Reduccion de SO{sub 2}-NO{sub x}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The project was divided in two well-differentiated parts: SO{sub 2} removal and NO{sub x} reduction. In both cases, carbon materials play a unique role in the processes, either as calcium sorbent support (SO{sub 2} removal) or as catalyst support and reducing agent (NO{sub x} reduction). Removal of SO{sub 2}. This process was carried out by calcium sorbents at relatively low temperature (T<300 degree centigree), forming CaSO{sub 3} (instead of CaSO{sub 4}) that decomposes at lower temperatures, making regeneration easier. High dispersion of the active species, CaO, has been obtained using carbon materials (activated carbons, chars, etc) and other inorganic compounds as supports. The effect of oxygen, carbon dioxide and steam in the reaction atmosphere and the regeneration process have been also investigated. Thermal regeneration is possible for several cycles, however, carbon gasification also takes place. To control, and to void that effect the reaction and regeneration temperatures should be carefully controlled and carbons with low reactivity should be selected. The process was scaled (100-2000) using briquette samples obtained by physical mixture of char and Ca(OH){sub 2}. The SO{sub 2} removal levels were similar to those found in the laboratory scale. NO{sub x} reduction. The possibility of using potassium containing coal-briquettes for NO and NO{sub x} reduction has been investigated. The preparation method of briquettes presents the advantage of using a binder agent (humic acid) which contains the catalyst (potassium). The system catalyst-binder-coal stays intimately joined by a moulding stage and subsequent pyrolysis, providing proper mechanical resistance to the coal-briquettes. With the purpose to improve the briquettes activity, different variables of the preparation process have been investigated (potassium content-added with the binder and/or KOH-. rank and mineral matter content of the coal precursor, pyrolysis temperature and pressure of the moulding stage). Potassium containing briquettes exhibit a considerable capacity for NO{sub x} reduction and, interestingly, are quite selective towards NO{sub x} reduction against oxygen gasification. This behaviour is very important, taking into account that one of the main disadvantages of carbonaceous materials in NO{sub x} pollution control is the great consumption of carbon due to oxygen combustion.

  5. Expresión del factor ? transformador del crecimiento (TGF-? y del factor de crecimiento derivado de las plaquetas (PDFG en la esclerodermia lineal

    Directory of Open Access Journals (Sweden)

    José Félix Restrepo

    2003-12-01

    Full Text Available La esclerodermia lineal (EL es una forma localizada de la enfermedad, caracterizada por la proliferación fibroblástica y los infiltrados linfocitarios perivasculares en la dermis. En los estadios terminales de la enfermedad, hay depósito de colágeno en exceso con atrofia cutánea y de los anexos, todo lo cual sugiere una alteración de la regulación de la función fibroblástica, con participación de los factores de crecimiento en la patogenia de la enfermedad. Este trabajo se planeó para examinar la expresión de los factores TGF-ß y PDFG en biopsias de piel de pacientes con EL y de controles sanos, con estudio inmunohistoquímico. Para idenficar el TGFß se emplearon dos anticuerpos policlonales TGF-ß1 (RaB4 y TGF-ß2 (CL-B1/29 y dos anticuerpos monoclonales para identificar el PDFG: PDFG-AA (3E-205 y PDFG-BB (1F-133. La tinción para TGF-ß1 y TGF-ß2 se observó alrededor de los vasos sanguíneos pequeños y de las glándulas sudoríparas tanto en la EL como en la piel normal. La tinción para PDGF-AA y PDGF-BB fue intensa en las células endoteliales y en las glándulas sudoríparas en la EL y en la piel normal. El infiltrado linfocitario y los haces colágenos anormales no se tiñeron para TGF- ? ni para PDGF. La intensidad y la extensión de la reactividad evaluada en los tejidos con una escala de 0 (ausencia de tinción a 4 (tinción notoria indican que la expresión de TGF-ß1, TGFß2, PDGF-AA y PDGF-BB son similares en la EL y en la piel normal. Nuestros hallazgos no apoyan la hipótesis según la cual la actividad fibroblástica excesiva y el depósito de colágeno anormal observados en la esclerodermia lineal estén asociados con alteraciones de la regulación del TGF-ß o del PDGF.

  6. Selección de cepa de microalgas para la producción de aceites como fuente de Biocombustibles y otros derivados

    OpenAIRE

    Guerrero-Barrantes, Maritza; Solera-Steller, Paola; Araya-Marchena, Mario

    2013-01-01

    Las algas se componen de organismos acuáticos que capturan luz solar y el dióxido de carbono para hacer la foto-síntesis y así producir su energía, y además producir aceites vegetales que se pueden transformar en biodiesel. Las microalgas crecen favorablemente en los trópicos, ya que no necesitan para su cultivo controlado la aplicación de temperatura y luz, esto hace que su producción en sistemas abiertos tenga un costo bajo. Muchos de estos organismos, entre ellos las microalgas, permiten l...

  7. Efectos tributarios derivados de la adopción de las normas internacionales de información financiera. caso: Venezuela.

    OpenAIRE

    Peña, Alirio

    2007-01-01

    SUMARIO Editorial. Luciani Toro, Laura Artículos Modelo de educación gerencial para el sector público. Una propuesta dirigida al ser, hacer y como ser. Model of managemental education for the public sector. A proposal addressed to the being, the doing and the being like. Bastidas, María Carolina La ciencia contable, su historia, filosofía, evolución y su producto. Accounting science, its history, philosophy, evolution and its product. Casal, Rosa Aura ...

  8. Mercantilización de la cultura, del saber y de la información en la sociedad del conocimiento y problemas éticos derivados

    Directory of Open Access Journals (Sweden)

    Bausá Arpón, Marta

    2016-07-01

    Full Text Available El objetivo de este trabajo es plantear algunos problemas éticos que pueden surgir del uso de las nuevas tecnologías de la comunicación, y que desafían en muchas ocasiones los valores tradicionales que se consideran establecidos en nuestra sociedad. Se pretende mostrar como las TIC han afectado de manera importante la evolución y desarrollo humano, y han modificado sustancialmente las relaciones interpersonales, especialmente en los jóvenes.

  9. Determinação de isoflavonas e capacidade antioxidante de alimentos industrializados à base de soja e/ou produtos derivados consumidos no Brasil

    OpenAIRE

    Marcela Roquim Alezandro

    2009-01-01

    A soja contém alto conteúdo protéico e de lipídeos poliinsaturados e representa a principal fonte de isoflavonas. Por este grão não fazer parte da dieta brasileira, produtos contendo soja surgiram no mercado como fontes de isoflavonas, adaptados ao paladar da nossa população. Os condimentos também têm sido incorporados aos ditos \\"alimentos funcionais\\" pela sua relação com efeitos benéficos à saúde. Este trabalho objetivou determinar o teor de isoflavonas dos produtos contendo soja e/ou deri...

  10. Síntese e modelagem molecular do novo derivado indolinônico como candidato a antiinflamatório COX-2 seletivo

    Directory of Open Access Journals (Sweden)

    J. L. SANTOS

    2009-01-01

    Full Text Available

    Os fármacos antiinflamatórios são sabidamente os mais comercializados em todo o mundo, e apesar disto apresentam sérios efeitos colaterais, sobretudo no que se refere ao trato gastrintestinal. A descoberta de novos protótipos com atividade e segurança terapêutica melhoradas continua sendo uma busca constante. Com o advento da química computacional torna-se mais fácil o estudo teórico do comportamento fisiológico de uma nova substância bem como a compreensão do possível mecanismo de ação destas novas moléculas. Assim, através de modelos matemáticos de moléculas e receptores estudouse neste trabalho o composto I (1-(2,6- diclorofenilindolin-2-ona quanto à sua possibilidade de inibir seletivamente a isoforma COX-2 da enzima prostaglandina endoperóxido sintase (PGHS, e também as melhores posições para a introdução de grupamentos químicos e modificações moleculares. Palavras-chave: indolinônico; COX-2; antiinflamatório.

  11. Canaric acid (3,4-seco-lupane derivative) isolated from propolis of Ceara, BR; Acido canarico (3,4-seco derivado do lupano) em propolis do Ceara

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Irineu L. de; Alves, Leonardo A.; Lemos, Telma L.G.; Monte, Francisco J.Q. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica]. E-mail: tlemos@dqoi.ufc.br; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Ciencias e Tecnologia. Setor de Produtos Naturais

    2007-07-15

    Phytochemical investigation of a propolis sample from Alto Santo - Ceara, Brazil, allowed identification of triterpenes (lupeol, lupenone, germanicone, Canaric acid) and flavonoids (quercetin, kaempferol and acacetin), which were identified by spectroscopic data (IR, MS, and NMR, including 2D techniques). This is the first report of Canaric acid in propolis. Propolis extract and flavonoids showed antioxidant activity using a DPPH radical scavenging assay. (author)

  12. Utilización de distintas glicosidasas para la obtención de carbohidratos bioactivos derivados de la lactosa y sacarosa

    OpenAIRE

    Villarejo Guerra, Virginia

    2013-01-01

    Resumen del Trabajo de Fin de Máster presentado a las I Jornadas de Estudiantes de Máster en Química Agrícola y Nuevos Alimentos celebradas en el Instituto de Investigación en Ciencias de la Alimentación CSIC-UAM (CIAL) del 3 al 4 de octubre de 2013.

  13. Synthesis and evaluation of phytotoxic activity of {alpha}-Santonin derivatives; Sintese e avaliacao da atividade fitotoxica de derivados da {alpha}-Santonina

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Elson S.; Barbosa, Luiz C.A.; Saliba, William A.; Arantes, Francisco F.P.; Demuner, Antonio J. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Quimica]. E-mail: elson@ufv.br; Silva, Antonio A. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Fitotecnia

    2009-07-01

    Mixtures of {alpha}-Santonin and various solvents were irradiated by either high or low pressure mercury lamps. The photochemical reactions afforded lumisantonin (11) (76% in acetonitrile), (3 S,3a S,9{beta}S)-3,6,6-trimethyl-3,3a,4,5-tetrahydronafto[1,2-b]furan-2,7({eta}6,9{beta}{eta}) dione (12) (100% in acetonitrile), 10{alpha}-acetoxy-3-oxo-1,7{alpha}H{eta},6,11{alpha}a{eta}-guaia-4-en-6,12-oli= de (8) (26% in acetic acid), 10{alpha}-hydroxy-3-oxo-1,7{alpha}a{eta},6,11{alpha}{eta}-guaia-4-en-6,12-olid= e (10) (32%) and (E)-3-((3 S,3a S,7{alpha}S)-3-methyl-2-oxo-6-(propan-2-ylidene)hexahydrobenzofuran- 7 - (7{alpha}{eta})-ylidene)propanoic acid (9) (44%) (in water/ acetic acid 1:1, v/v). Lactone 12 was also prepared by irradiation of lumisantonin in diethyl ether. Lactones 8 and 10 were converted, respectively, into the 10 {alpha}-acetoxy-3{alpha}-hydroxy-1,7{alpha}H,6,11{alpha}H-guaia-4-en-6,12-olid= e (13) (87%) and 3a,10a-dihydroxy-1,7{alpha}H,6,11{alpha}H-guaia-4-en-6,12-olide (14) (75%) by sodium borohydride reduction. The effects of the compounds on the development of radicle of Sorghum bicolor and Cucumis sativus were evaluated. (author)

  14. Evaluation of glycerol derivative as emulsifier for oil based drilling fluids; Avaliacao de derivados de glicerina como emulsificante para fluidos de perfuracao de base oleo

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Susan A. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica; Cavalcanti, Milena Y.; Rodrigues Junior, Jorge; Lachter, Elizabeth R.; Nascimento, Regina Sandra V. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Quimica

    2008-07-01

    In view of the growing search for new applications for the surplus glycerine of biodiesel production, the use of a glycerine derivative as emulsifier in oil based muds is proposed in this work. Glycerine monooleate was synthesized through esterification reaction, and characterized by NMR{sup 13}C. Its applicability as emulsifier was verified through electric stability tests performed on inverted phase drilling fluids. The obtained results were compared with two formulations containing different emulsifiers (sorbitol monooleate and trimethylolpropane monooleate). It was also evaluated the rheological properties of the formulated fluids through standard tests. It was verified that the fluid that contained the glycerine derivative showed considerably better electric stability results than the other systems. It also presented rheological properties similar to the ones shown by the system that contained the commercial emulsifier (sorbitol monooleate). Thus, it was found that glycerine monooleate is a potential substitute to the currently emulsifiers (author)

  15. Application of diagnosis and monitoring area contaminated by petroleum derivatives; Aplicacao da tecnica de caminhamento eletrico em area contaminada por derivados de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Cesar Augusto [Pos-graduacao em Geociencias em Meio Ambiente, IGCE - UNESP, Rio Claro, SP (Brazil)], E-mail: cesargeologia@yahoo.com.br; Dourado, Joao Carlos; Braga, Antonio Celso de Oliveira [Dept. de Geologia Aplicada, IGCE - UNESP, Rio Claro, SP (Brazil)], E-mails: jdourado@rc.unesp.br, acobraga@rc.unesp.br

    2006-07-15

    Geophysical methods are useful technic of geological investigation, thoroughly employed to diagnosis and monitoring contaminated areas, in conjunction with direct techniques of investigation such as chemical analyses. Among these, electric resistivity is more usually used in studies of contaminants in soil and groundwater, due to the high contrast of electric properties between the soil and the pollutant types frequently found, essentially constituted of composed organic and inorganic. Geophysical studies in impacted areas by petroleum products may be describe by anomalies of both low resistivity and high resistivities, confirmed as contaminant by chemical analyses. This apparent contradiction can reflect processes of degradation of the contaminants, directly associated with its residence time in the soil, through the generation of by-products that change the physical properties of the soil and groundwater, principally for the mineral dissolution by action of organic acids and by formation of minerals of oxides and hydroxides minerals. Natural attenuation defines a series of physical, chemical and biological processes that allow the degradation, dispersion and dilution of contaminants in a natural form, in other words, free from human intervention. This paper presents the application of electrical profiling technique in a contaminated industrial area for benzene, toluene, xylene, 1,2 dichloroethene and inorganic salts and it discusses the physical alterations of the contaminated soil through the obtained results, under the optics of the Natural Attenuation in course in the area of study. (author)

  16. Obtenção de nanoanticorpos e síntese de compostos antichagásicos derivados de tiossemicarbazona

    OpenAIRE

    Blau, Lorena [UNESP

    2009-01-01

    A doença de Chagas ou Tripanossomíase americana é ainda um dos maiores problemas endêmicos na América Latina desde sua descoberta 100 anos atrás. Em 2006, havia aproximadamente 7,6 milhões de casos de infecção por Trypanosoma cruzi nos 21 países latino americanos. Cerca de 90 milhões de pessoas estão sobre o risco de contrair a infecção. O número de mortes e novos casos atribuídos a essa doença são respectivamente 21.000 e 200.000 no ano de 2000. Dois fármacos são usados particularmente para ...

  17. Estudio descriptivo de los procesos de IT más prevalentes derivados de problemas durante el embarazo en mujeres de la comunidad valenciana

    Directory of Open Access Journals (Sweden)

    Emilio Martínez Marc

    2014-01-01

    Full Text Available El embarazo es una situación incluida en la acción protectora de la Seguridad Social. En la provincia de Alicante, durante el periodo 2008 a 2012 el número de mujeres cotizantes ha disminuido un 9,04%, el de nacimientos un 17,4% y el de prestaciones por maternidad el 23,86%. La incapacidad temporal global ha bajado de enero 2012 a enero 2013 más de un 20% y la de la amenaza de aborto un 4,4%. La protección de la situación de riesgo en el embarazo, que tiene la consideración de contingencia profesional, ha aumentado en Alicante un 155% de 2008 a 2012, ya que es una protección más ventajosa económicamente para la mujer.

  18. Structure, reactivity and synthesis of piramidines and their derivates (dihidroperimidines and perimidinones); Estructura, reactividad y sintesis de perimidinas y de sus derivados (dihidroperimidinas y perimifinonas)

    Energy Technology Data Exchange (ETDEWEB)

    Claramunt, R.M.; Dotor, J.; Elguero, J. [Departamento de Quimica Organica, Facultad de Ciencias, UNED, Madrid (Spain)

    1995-12-01

    This review reports 346 references dealing with structure, reactivity and synthesis of pyrimidines and their derivatives (mainly 2,3-dihidroperimidines, 2-perimidinones and perimidinium salts). Special emphasis has been made on spectroscopy and structural properties as well as on reactivity. 346 refs.

  19. Institucionalidad en torno a los mercados de carbono y los mecanismos de flexibilización derivados del Protocolo de Kioto

    Directory of Open Access Journals (Sweden)

    Piedad Patricia Restrepo

    2008-01-01

    Full Text Available El artículo presenta un acercamiento a las instituciones y regulaciones derivadas de la UNFCCC y el Protocolo de Kioto. Se analiza el comportamiento de los mercados de reducción de emisiones en sus ya casi tres años de funcionamiento, especialmente la inestabilidad de los precios en los diversos mercados europeos y su relación con los CER, estos últimos emitidos gracias a los proyectos provenientes del Mecanismo de Desarrollo Limpio (MDL desarrollados en los países en vías de desarrollo. Se establecen los alcances y limitaciones del MDL y finalmente se concluye acerca de las perspectivas de estos mercados y sus oportunidades.

  20. Catalizador y proceso catalítico para la eterificación/reducción de furfuril derivados a tetrahidro-furfuril éteres

    OpenAIRE

    Corma, Avelino; Dómine, Marcelo Eduardo; Valencia, Susana

    2012-01-01

    La presente invención se refiere a un procedimiento para la obtención de tetrahidro-furfuril éteres, caracterizado porque comprende realizar reacciones consecutivas de eterificación / reducción a partir de un compuesto que contenga uno o más anillos furánicos, en presencia de uno o más alcoholes y uno o más catalizadores, y eventualmente en presencia de H{sub,2}. El proceso catalítico puede llevarse a cabo en una reacción en cascada (“one-pot”) trabajando en condici...

  1. Actividad antibacteriana, degradación hidrolítica y microbiana y citotoxicidad in vitro de poliuretanos sintetizados con polioles derivados del aceite de higuerilla

    Directory of Open Access Journals (Sweden)

    Yomaira L. Uscategui

    Full Text Available Biological activities from polyurethanes (PUs synthesized from polyols (derived from castor oil and isophorone diisocyanate were evaluated. In vitro degradability was evaluated by phosphate buffered saline (PBS and antibacterial degradation with Escherichia coli and Pseudomonas aeruginosa. The biocompatibility was analyzed by: i the antimicrobial activity against E. coli, S. aureus and P. aeruginosa, and ii in vitro cytotoxicity assays using mouse embryonic fibroblast cell line L-929 in direct contact with the PUs and with NIH/3T3 cells in indirect contact with the PUs degradation products. PUs with polyol P1 (2,64% molar relation of pentaerythritol and castor oil was the material with better biodegradation properties: 1.125±0.110% in 72 h by PBS at 100 ºC. In general, all materials were degraded up to 1.000±0.223% and 2.251±0.010% in 72 h by E. coli and P. aeruginosa, respectively. On the other hand, it was determined a close relationship between functionality of polyol and bacterial inhibition. The antibacterial effect of the PUs decreased by 67% for E. coli, 55% for S. aureus and 56% for P. aeruginosa after 24 h. Chemical modification of castor oil did not generate a cytotoxic effect on the tested cell lines. The evaluated materials are suggested as candidates to obtain biomaterials due to their mechanical properties and biocompatibility presented in untransformed cells.

  2. Efecto del uso de β-glucanasas y derivados de levaduras en la calidad del vino espumoso Verdejo de larga crianza.

    OpenAIRE

    Sandoval Manzano, Raúl

    2015-01-01

    El presente estudio se ha realizado con el fin de comprobar la efectividad de diversos tratamientos enológicos en vinos espumosos de larga crianza de la variedad Verdejo. Se elaboraron 4 tipos de vinos espumosos partiendo del mismo vino base y un licor de tiraje. Los tratamientos fueron un vino con cortezas de levaduras secas inactivas, otro con un producto a base de autolisados de levaduras, otro con β-glucanasas y un vino control. Los vinos se sometieron a una segunda fermentación en ...

  3. Isolation and evaluation of cytotoxic potential of phenolic derivatives from Schinus terebinthifolius Raddi (Anacardiaceae); Isolamento e avaliacao do potencial citotoxico de derivados fenolicos de Schinus terebinthifolius Raddi (Anacardiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Jeferson S.; Sartorelli, Patricia; Lago, Joao Henrique G. [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil). Inst. de Ciencias Ambientais, Quimicas e Farmaceuticas; Matsuo, Alisson L., E-mail: joao.lago@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Dept. de Micro, Imuno e Parasitologia

    2012-07-01

    The EtOH extract from leaves of S. terebinthifolius was subjected to partition between EtOH:H{sub 2}O and hexane, CH{sub 2}Cl{sub 2}, and EtOAc. The phases obtained were evaluated in vitro against human tumoral cell lines and the EtOAc phase exhibited activity. Chromatographic procedures afforded gallic acid (1), methyl (2) and ethyl (3) gallates, trans-catechin (4), quercitrin (5), and afzelin (6), being the first occurrence of 1, 4 and 6 in S. terebinthifolius. In vitro cytotoxic evaluation of 1 - 6 indicated that gallic acid (1) displayed higher activity than ethyl gallate (3) against HL-60 and HeLa cells, while compounds 2, 4 - 6 were inactive. (author)

  4. Pumping propagation and influence of oil derivatives transport in a pipeline network; Propagacao e influencia de bombeamento no transporte de derivados de petroleo em uma rede de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Camila Baldissera de [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Kluppel, Liege Bauer; Neves Junior, Flavio [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Ribas, Paulo Cesar [Petroleo Brasileiro S.A (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa e Desenvolvimento

    2012-07-01

    This paper presents the work developed on a pipeline network that transports oil derivatives. The transport occurs in batches of a specific product, each one having a defined route: the pumping origin, a destination for its receipt and the pipelines which the product is moved through. The network studied has a total of thirty pipelines connected by fourteen possible areas of pumping and/or receiving, this makes it not trivial to obtain the batches order in the pipeline. In order to obtain the passage of batches ordered list in the pipeline network, was developed an algorithm capable of propagating a batches list that only have route, start time and end time of pumping in the origin. This algorithm is part of a larger project whose goal is to obtain a tool to aid the process of operational decision making in a real pipeline network. The developed module can also generate the entry and exit times of each batch for each pipe through which it passes. With this information, analysis and/or validations can be made. At the end of the process, the result is a list of all the pumped batches in all pipes where it must go by. Thus, it is made a small pos-processing where the list is sorted, first by pipeline and then by start time of entry into the duct, which naturally causes the passage of the batches list in the ducts to be obtained. This work is based on the development presented by Czaikowski et al (2008). (author)

  5. Oil transport scheduling in a pipeline with a characteristic operation; Otimizacao das operacoes de transporte de derivados em um poliduto com multiplas sangrias

    Energy Technology Data Exchange (ETDEWEB)

    Kira, Guilherme; Magatao, Leandro; Arruda, Lucia Valeria Ramos; Silva, Marcos Henrique da [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Lara, Lucas El Ghoz [Petroleo Brasileiro S.A (PETROBRAS), Rio de Janeiro, RJ (Brazil); Ribas, Paulo Cesar [Petroleo Brasileiro S.A (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa e Desenvolvimento

    2012-07-01

    This work presents an optimization structure to support the operational decision making of scheduling activities in a multi product pipeline with multiple deliveries. This pipeline connects, in sequence, 6 operational areas: one is the main refinery, and the 5 remaining are distribution centers, each one with specific capacity of storage. Basically, the refinery pumps derivatives, such as diesel and gasoline, in a unidirectional flow to distribution centers, in a way to supply their demands. The solution kernel is underlined in a hybrid structure, using heuristics and Mixed Integer Linear Programming (MILP) modeling, executed iteratively. Details of storage curves and flow rate of pipelines are obtained in the proposed approach, expanding the results of Kira et al. (2010). Additionally, the proposed approach is able to deal with discrete demands along the scheduling horizon. Thus, this hybrid structure makes possible to obtain operational scheduling solutions at a low CPU times (few minutes), using real data scenarios, whose horizon length has at least 30 days. (author)

  6. Modification of a cellulose derived for your application on enzyme immobilization;Modificacao de um derivado celulosico para sua aplicacao na imobilizacao de enzimas

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Elaine S.; Rodriguez, Ruben J.S.; Lamonica, Alano C., E-mail: ecarvalho@uenf.b [Universidade Estadual do Norte Fluminense Darcy Ribeiro (LAMAV/UENF), Campos dos Goytacazes, RJ (Brazil). Lab. de Materiais Avancados; Tavares, Maria Ines B. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano

    2009-07-01

    The chemical modification of (acrylamidomethyl) cellulose acetate propionate (AMCAP) was done through the technique of grafting via radical using acrylic acid as modifier, with the objective to make the polymer more hydrophilic. The structural characterization of AMCAP and modified AMCAP-H{sub 2}O{sub 2} was analysed by using the technique of {sup 13}C-nuclear magnetic resonance (NMR-{sup 13}C). By the techniques differential scanning calorimetry analysis (DSC) and thermogravimetric analysis (TGA), the thermal properties was characterized and the hydrophobic / hydrophilic character was determined by measurements of the contact angle. The results show that occurred the change intended with the introduction of acrylic acid in the side chain of the polymer, increasing the hydrophilic character on the AMCAP. (author)

  7. Synthesis by plasma and characterization of semiconductor compounds derived of polyacetylene; Sintesis por plasma y caracterizacion de compuestos semiconductores derivados del poliacetileno

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, M.; Cruz, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [ESIQIE-IPN, 07738 Mexico D.F. (Mexico); Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)

  8. Síntesis de compuestos organoselénicos derivados del hidroxitirosol. Determinación de su actividad como antioxidantes

    OpenAIRE

    Gómez Carretero, Antonio

    2012-01-01

    Texto completo descargado desde Teseo 1. Introducción Los polifenoles son una amplia familia de compuestos que se encuentran, entre otros alimentos, en la fruta, la verdura, el vino, el té, el cacao y el aceite de oliva virgen extra y que muestran una marcada actividad antioxidante, que se traduce en una contrastada actividad en la prevención de enfermedades cardiovasculares, cáncer, enfermedades neurodegenerativas, diabetes u osteoporosis . Uno de los polifenoles más efectivos como ...

  9. Sorption of oil in the polyurethane from oil or castor oil; Sorcao de oleo no poliuretano derivado do petroleo ou do oleo de mamona

    Energy Technology Data Exchange (ETDEWEB)

    Florentino, Wagner M; Goulart, Shane A.S.; Mulinari, Daniella R. [Centro Universitario de Volta Redonda (UniFOA), Volta Redonda, RJ (Brazil)], e-mail: wagner-can@hotmail.com

    2011-07-01

    The oil outpouring has caused serious environmental problems. To minimize this damage polyurethane foams have been used. In this work, the use of polyurethane from oil and castor oil, in different polyol/diisocyanate mass ratios, to absorb oil was evaluated. Results revealed that the proportion of polyol and diisocyanate influenced in the sorption capacity and the polyurethane from castor oil presented greater sorption capacity. Of this way, can say that the polyurethane from oil can be replaced by castor oil, contributing to sustainable development. (author)

  10. Niveles séricos del factor neurotrófico derivado del cerebro durante la gestación normal y la preeclampsia

    Directory of Open Access Journals (Sweden)

    Liza Lorena Colorado Barbosa

    2016-04-01

    Conclusiones. El BDNF puede participar en la regulación del peso corporal y el metabolismo de la glucosa en mujeres gestantes, pero el nivel de BDNF, solo o en conjunto con otras variables, no puede explicar la preeclampsia.

  11. Estudo comparativo de amidos termoplásticos derivados do milho com diferentes teores de amilose Comparative studies of corn thermoplastic starches with different amylose content

    Directory of Open Access Journals (Sweden)

    Elisângela Corradini

    2005-11-01

    Full Text Available Amidos de milho contendo aproximadamente 72 e 100 % de amilopectina foram convertidos em amidos termoplásticos por processamento em um misturador intensivo a 160 ºC, usando glicerol como plastificante. Os amidos termoplásticos foram condicionados em ambiente de 53 ± 2% u.r. e caracterizados por medidas de absorção de água, difração de raios X, ensaios mecânicos de tração e por análises dinâmico mecânicas (DMA. O amido com menor teor de amilopectina apresentou maior viscosidade durante o processamento, que foi atribuída à estrutura da amilose. Os amidos termoplásticos TPS1 (72% de amilopectina e TPS2 (100% de amilopectina não mostraram diferenças apreciáveis nas propriedades de absorção de água. Após duas semanas de armazenamento, o TPS1 apresentou estrutura semicristalina, enquanto o TPS2 apresentou estrutura totalmente amorfa. Após seis semanas ocorreu um aumento da cristalinidade do TPS1 e ocorreu a formação de estruturas cristalinas no TPS2. As propriedades mecânicas e dinâmico-mecânicas foram afetadas pela cristalinidade do amido que é função da razão amilose/amilopectina.Corn starches with approximately 72% and 100 % of amylopectin were processed in an intensive mixer connected to a torque rheometer in the presence of glycerol (plasticizer at 160ºC. The thermoplastic starches were conditioned at 53 ± 2% of relative humidity for two weeks and characterized by X-ray diffraction, tensile test and dynamical mechanical analysis (DMA. The starch with lower amylopectin content presented higher viscosity during the processing which was attributed to linear amylose chains. The thermoplastic starches TPS1 (72% of amylopectin and TPS2 (100% of amylopectin did not display significant differences in water absorption. After two weeks of aging, TPS1 exhibited semicrystalline structure, whereas TPS2 presented a amorphous structure. After six weeks, the crystallinity of TPS1 increased and some crystalline behavior could be detected in TPS2. The mechanical and dynamical mechanical properties were affected by starch crystallinity, which is a function of amylose/amylopectin ratio.

  12. Efectos derivados del cambio del factor calidad por el factor precio en la contratación de ingeniería de consulta

    Directory of Open Access Journals (Sweden)

    Germán Silva Fajardo

    2008-05-01

    Full Text Available El conocimiento fue determinante en la contratación de expertos para realizar las primeras obras la naciente Colombia. Con la formación en el extranjero, en los siglos IXX y en los albores del XX, de algunos ingenieros y el nacimiento de las primeras facultades de ingeniería, el conocimiento empezó a divulgarse, siendo el conocimiento, la ética y la calidad los elementos obvios de selección. Al requerirse obras cada vez más grandes y complejas se crean las primeras empresas de ingeniería de consulta; se promovió su asociación con consultores internacionales que les permitieran ejecutarlas, transferir y asimilar experiencia, conocimiento y capacitar a numerosos profesionales. La selección de los consultores, hasta la década de los 80 del Siglo XX, se baso en el conocimiento y la calidad, mientras que el precio era el fruto de una negociación más no un factor de selección. La relación Cliente -Consultor se basaba en la mutua confianza. Con la masificación de la formación y especialización de ingenieros, la oferta empezó a sobrepasar la demanda. Se multiplicaron las compañías y las entidades contratantes dispusieron de múltiples opciones. La competencia derivó en la necesidad de regulación de la contratación estatal. Sucesivas leyes y crecientes reglamentaciones fueron expedidas, hasta llegar a la Ley 80 de 1993 en la que el precio fue introducido como factor decisivo de selección. Equivocadamente el Estado propició una desenfrenada competencia por precio sin introducir mecanismos que garantizaran la calidad de los productos. La falta de planeación de largo plazo llevó a contratar proyectos en forma improvisada, obviando los indispensables estudios de preinversión. Se propició la consultoría informal, la competencia desleal de universidades y el deterioro de los salarios de los profesionales. La posibilidad de otorgar y de obtener contratos sin requerir mayores meritos, alentó la corrupción, todo lo cual derivo en obras deficientes, y en el claro debilitamiento del sector empresarial de la consultoría. Los litigios y reclamaciones que inundan los tribunales de justicia son el resultado de esta equivocada política. Los organismos multilaterales y el Gobierno, alarmados con los resultados, promueven modificaciones a las leyes de contratación, se aprueba la Ley 1150 de 2007 y se expide el decreto reglamentario No 66 del año 2008, legislación que en mi opinión tampoco permitirá corregir los vicios de la Ley 80 y que deberá ser reformada de inmediato./ The knowledge was crucial in hiring experts to conduct the first works the nascent Colombia. With training abroad a few engineers in IXX century and the dawn of the XX century and the birth of the first faculties of engineering, knowledge began to spread, and the knowledge, ethics and quality was the obvious elements for their selection. At the required works for the development of the country increasingly in size and complexity, was create the first engineering consulting firms , and promoted its association with international consultants to enable them to execute, transfer and assimilation experience, knowledge and training of professionals. The selection of consultants remains until the 80, knowledge-based and the quality and price negotiated more non selection factor. The relationship Client-Consultant was based on mutual confidence. With overcrowding of training and specialization of engineers supply began to exceed demand. It multiplied companies and contracting entities were given multiple choices. The competition resulted in the need for state contract regulations. Successive laws and regulations were issued, reaching Act 80 of 1993 in which the price was introduced as a decisive factor in selection. A big mistake was made by the State enabling price competition without introducing mechanisms to ensure product quality. The lack of planning led to hire long-term projects in improvised form, disregarding the essential pre-investment studies. It led to the informal consultation, unfair competition from universities and the deterioration of wages of professionals. The possibility of granting and obtaining contracts without requiring most deserving, encouraged corruption, all of which resulted in poor work, and in the clear weakening of the business of consulting. The litigation and claims that flooded the courts are the result of this misguided policy. Alarmed multilateral agencies and the Government with the results, promoting changes to laws on hiring, approving the 1150 Act, 2007 and issued the decree No. 66 of 2008, legislation that not allowed to correct the deficiencies of the Act 80 and that must be reformed immediately.

  13. Marcadores moleculares derivados de sequências expressas do genoma café potencialmente envolvidas na resistência à ferrugem

    Directory of Open Access Journals (Sweden)

    Samuel Mazzinghy Alvarenga

    2011-08-01

    Full Text Available O objetivo deste trabalho foi identificar marcadores moleculares relacionados à resistência do cafeeiro (Coffea arabica à ferrugem (Hemileia vastatrix. Foram identificadas sequências de DNA potencialmente envolvidas na resistência do cafeeiro a doenças, por meio de análise "in silico", a partir das informações geradas pelo Projeto Brasileiro do Genoma Café. A partir das sequências mineradas, foram desenhados 59 pares de iniciadores para amplificá-las. Os 59 iniciadores foram testados em 12 cafeeiros resistentes e 12 susceptíveis a H. vastatrix. Vinte e sete iniciadores resultaram em bandas únicas e bem definidas, enquanto um deles amplificou fragmento de DNA em todos os cafeeiros resistentes, mas não nos suscetíveis. Esse marcador molecular polimórfico amplificou uma região do DNA que corresponde a uma janela aberta de leitura parcial do genoma de C. arabica que codifica uma proteína de resistência a doenças. O marcador CARF 005 é capaz de diferenciar os cafeeiros analisados em resistentes e susceptíveis a H. vastatrix.

  14. Evaluación de algunos parámetros fisicoquímicos y nutricionales en humus de lombriz y composts derivados de diferentes sustratos

    Directory of Open Access Journals (Sweden)

    Myriam Rocío Melgarejo

    2010-07-01

    Full Text Available Se determinaron algunas propiedades fisicoquímicas y nutricionales en cuatro humus de lombriz obtenidos a partir de desechos de cocina y de huerta, pulpa de café, basuras biodegradables y residuos de rosas y en dos composts provenientes de residuos de rosas y de clavel. Las propiedades evaluadas fueron: humedad de campo, pH en agua (1:5, conductividad eléctrica (1:5, cenizas, materia orgánica, sílice (SiOj y capacidad de intercambio cationico por el método de extracción con acetato de amonio IN pH 7,0 y por el método de Harada. Así mismo, se determinó el contenido de hidrosolubles y su efecto sobre la germinación de semillas de Berro (Lepidium sativum; finalmente se realizó un análisis nutricional que comprendió la cuantificación de los elementos nutrientes en su forma total y disponible.

  15. Snake venoms components with antitumor activity in murine melanoma cells; Componentes derivados de venenos de serpentes com acao antitumoral em celulas de melanoma murino

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Rodrigo Guimaraes

    2012-07-01

    Despite the constant advances in the treatment of cancer, this disease remains one of the main causes of mortality worldwide. So, the development of new treatment modalities is imperative. Snake venom causes a variety of biological effects because they constitute a complex mixture of substances as disintegrins, proteases (serine and metalo), phospholipases A2, L-amino acid oxidases and others. The goal of the present work is to evaluate a anti-tumor activity of some snake venoms fractions. There are several studies of components derived from snake venoms with this kind of activity. After fractionation of snake venoms of the families Viperidae and Elapidae, the fractions were assayed towards murine melanoma cell line B16-F10 and fibroblasts L929. The results showed that the fractions of venom of the snake Notechis ater niger had higher specificity and potential antitumor activity on B16-F10 cell line than the other studied venoms. Since the components of this venom are not explored yet coupled with the potential activity showed in this work, we decided to choose this venom to develop further studies. The cytotoxic fractions were evaluated to identify and characterize the components that showed antitumoral activity. Western blot assays and zymography suggests that these proteins do not belong to the class of metallo and serine proteinases. (author)

  16. Mapa Sociolinguistico. Analisis demolinguistico de la Comunidad Autonoma Vasca derivado del padron de 1986 (Sociolinguistic Map. Demolinguistic analysis of the Autonomous Basque Community derived from the 1986 Census).

    Science.gov (United States)

    Basque Autonomous Community, Vitoria (Spain). General Secretariat of Linguistic Policy.

    Sociolinguistic data are presented in the form of sophisticated maps and tables in this pioneering study on the status of the Basque language. Based on information collected from the 1986 census, the major demographic characteristics of Basque are examined in order to ascertain the factors and processes that have contributed to its current status.…

  17. Isolamento e avaliação do potencial citotóxico de derivados fenólicos de Schinus terebinthifolius Raddi (Anacardiaceae

    Directory of Open Access Journals (Sweden)

    Jeferson S. Santana

    2012-01-01

    Full Text Available The EtOH extract from leaves of S. terebinthifolius was subjected to partition between EtOH:H2O and hexane, CH2Cl2, and EtOAc. The phases obtained were evaluated in vitro against human tumoral cell lines and the EtOAc phase exhibited activity. Chromatographic procedures afforded gallic acid (1, methyl (2 and ethyl (3 gallates, trans-catechin (4, quercitrin (5, and afzelin (6, being the first occurrence of 1, 4 and 6 in S. terebinthifolius.In vitro cytotoxic evaluation of 1 - 6 indicated that gallic acid (1 displayed higher activity than ethyl gallate (3 against HL-60 and HeLa cells, while compounds 2, 4 - 6 were inactive.

  18. Evaluación terapéutica de los derivados sanguíneos en coagulopatías, en la ciudad de Bogotá

    Directory of Open Access Journals (Sweden)

    Jaime Rodríguez Torres

    1972-10-01

    Full Text Available Se hace una evaluación de la eficacia de los primeros críoprecipitados y PRP, preparados en el Banco Nacional de Sangre, con los que se trataron 12 pacientes con diferentes coagulopatías incluyendo 8 hemofilias, 2 coagulopatías por mordedura de serpiente y 4 púrpuras tromcitopénicos, con resultados satisfactorios.

  19. Nuevas metodologías para la determinación de nonilfenol, sus derivados etoxilados y parabenos en muestras medioambientales

    OpenAIRE

    Núñez García-Cuerva, Laura

    2011-01-01

    El estudio de nuevos compuestos químicos, denominados contaminantes emergentes, se ha convertido en objetivo prioritario para la Organización Mundial de la Salud (OMS) y para las agencias de protección medioambiental (EPA). Es por ello que resulta necesario el desarrollo de métodos analíticos de elevada sensibilidad y selectividad para la determinación de estos compuestos, ya que lamentablemente son pocos los existentes actualmente. Lo ideal sería disponer de métodos respetuoso...

  20. Risks of low dose ionising radiation exposures Riesgos derivados de la exposición a dosis bajas de radiación ionizante

    Directory of Open Access Journals (Sweden)

    Almudena Real Gallego

    2010-12-01

    Full Text Available Although ionising radiation has been shown to have several beneficial applications for humans, it can also produce detrimental effects in humans and the environment. To adequately protect man and environment from the potential harmful effects of ionising radiation, is essential to know in detail the biological effects produced by it, its characteristics and the various factors that influence these effects. That is the objective of this article, describe the current status of knowledge about biological effects induced by ionising radiation, with special emphasis on those effects occurring after low dose exposures.La radiación ionizante ha mostrado tener diversas aplicaciones beneficiosas para el hombre, pero también puede dañar la salud de las personas y el medio ambiente. Para proteger adecuadamente al hombre de los posibles efectos nocivos de la radiación ionizante es imprescindible conocer en detalle los efectos biológicos producidos por esta, sus características y los distintos factores que influyen en dichos efectos. Ese es el objetivo de este artículo: describir el estado actual del conocimiento sobre los efectos biológicos que puede producir la radiación ionizante, con especial énfasis en aquellos efectos que se producen tras la exposición a dosis bajas.

  1. Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives; Incorporacao de fluconazol em ineditos derivados do copolimero PMMA-g-PEG

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A., E-mail: vmrebello@yahoo.com.br [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2014-07-01

    The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

  2. PERCEPCIÓN DOCENTE DEL DESARROLLO EMOCIONAL Y CREATIVO DE LOS ESCOLARES DERIVADO DEL DISEÑO COLABORATIVO DE DIGITAL STORYTELLING

    Directory of Open Access Journals (Sweden)

    M. Esther del Moral Pérez

    2018-01-01

    Full Text Available El diseño colaborativo de digital storytelling (DST puede convertirse en una estrategia e®caz para potenciar múltiples habilidades y competencias en esco- lares, al ofrecerles la oportunidad de crear sus propias historias apoyándose en herramientas digitales. Concretamente, esta investigación constata: a el cambio percibido por el profesorado sobre el desarrollo emocional y creativo alcanzado por el alumnado de Educación Infantil y Primaria (N=282, tras participar en un proyecto colaborativo de narración digital impulsado por la Consejería de Educación; y b el nivel de expresión emocional y creativa plasmada en los relatos ®nales elaborados. El análisis descriptivo muestra las valoraciones cualitativas del profesorado relativas al cambio percibido en el nivel de habilidades emocionales y creativas desarrollado por los escolares tras el diseño de DST, utilizando 13 indicadores cualitativos. Igualmente, el nivel de expresión emocional y creativa plasmada en los relatos elaborados (N=14 es sometido a evaluación experta. Los resultados subrayan que – a jui- cio de los docentes– esta narrativa digital colaborativa ha potenciado las habi- lidades emocionales del alumnado de Infantil, destacando las alumnas por su capacidad empática y por preocuparse por los demás , así como por cumplir lo que se proponen . Respecto a las habilidades emocionales, ellas se adaptan me- jor a las situaciones nuevas e identifican y resuelven problemas creativamente . Asimismo, las alumnas de Primaria sobresalen por su desarrollo emocional y creativo, y los cursos superiores presentan más empatía y preocupación por los demás , reflexión crítica y sensibilidad estética . Tras analizar los relatos ®- nales, los expertos reconocen que todos poseen originalidad y son adecuados a su intencionalidad, aunque prima el carácter logocéntrico que minimiza su impacto emocional. Resaltan la empatía y poder persuasivo de los personajes, especialmente en Primaria. Se puede a®rmar que las temáticas abordadas, las técnicas audiovisuales adoptadas y la ejecución colaborativa proporcionaron un escenario adecuado para ejercitar habilidades emocionales y creativas.

  3. Safrol e eugenol: estudo da reatividade química e uso em síntese de produtos naturais biologicamente ativos e seus derivados

    Directory of Open Access Journals (Sweden)

    Costa Paulo R. R.

    2000-01-01

    Full Text Available The chemical reactivity of safrole, eugenol, piperonal, vanillin and derivates toward ozone, aluminium chloride, brominating agents and butyl lithium was investigated. The synthesis of naturally occuring anthraquinones, furonaphthoquinones, naphthoquinones, lignans and pterocarpans from these easily available staring materials is also discussed.

  4. Cytotoxic derivatives of withanolides isolated from the leaves of Acnistus arborescens; Derivados citotoxicos de vitanolidos isolados das folhas de Acnistus arborescens

    Energy Technology Data Exchange (ETDEWEB)

    Minguzzi, Sandro, E-mail: sming@uems.b [Universidade Estadual de Mato Grosso do Sul, Navirai, MS (Brazil). Curso de Quimica; Barata, Lauro E.S. [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica; Cordell, Geoffrey A. [Natural Products Inc., Evanston, IL (United States)

    2011-07-01

    In view of anticancer activity of 7 beta-acetoxywithanolide D (2) and 7beta-16beta-diacetoxywithonide D (3), isolated from the leaves of Acnistus arborescens (Solanaceae), five withanolide derivatives were obtained and their structures were determined by NMR, MS and IV data analysis. The in vitro anticancer activity of these derivatives was evaluated in a panel of cancer cell lines: human breast (BC-1), human lung (Lu1), human colon (Col2) and human oral epidermoid carcinoma (KB). Compounds 2a (acetylation of 2), 3b (oxidation of 3) and 2c (hydrogenation of 2) exhibited the highest anticancer activity against human lung cancer cells, with ED{sub 50} values of 0.19, 0.25 and 0.63 mug/mL, respectively. (author)

  5. APLICAÇÃO DE ALTA PRESSÃO ISOSTÁTICA NA PRODUÇÃO DE DERIVADOS LÁCTEOS: UMA REVISÃO

    Directory of Open Access Journals (Sweden)

    Ana Carolina Nunes de Morais

    2014-10-01

    Full Text Available A Alta Pressão Isostática (API tem ganhado destaque em diversos setores da indústria, inclusive o de laticínios. Esta tecnologia emergente é eficaz para garantir aos alimentos segurança microbiológica semelhante aos processos térmicos convencionais (pasteurização, com a vantagem de preservar as características sensoriais e nutricionais, oferecendo ao consumidor produtos mais próximos ao natural. O objetivo do presente estudo foi realizar uma revisão de literatura sobre a aplicação e as perspectivas da API na indústria de alimentos, principalmente no tocante à indústria de laticínios.

  6. Diversos aspectos atinentes a la esclavitud en Buenos Aires derivados del análisis de las fuentes notariales, 1821-1830

    Directory of Open Access Journals (Sweden)

    Miguel A. Rosal

    2004-11-01

    Full Text Available El presente trabajo constituye un avance de la investigación sobre el negro porteño a partir de la segunda década post-revolucionaria, a través de la consulta de los distintos registros de los Protocolos Notariales, conservados en el Archivo General de la Nación. En síntesis, el artículo pretende ilustrar aspectos que quizá no hayan merecido la necesaria atención por parte de los investigadores de la problemática afroporteña durante el período independiente; nos referimos al análisis del fenómeno de la manumisión, preciada o graciosa, de la libertad futura condicional, de la figura del negro propietario de bienes inmuebles y de esclavos, como así también de los testamentos de las personas "de color". Parece útil, entonces, intentar estos estudios que nos podrán iluminar sobre aspectos poco o nada conocidos de los morenos y pardos de Buenos Aires durante el siglo XIX.

  7. What We Fund - Alcohol

    International Development Research Centre (IDRC) Digital Library (Canada)

    NCDP

    Le tableau qui suit présente les sujets clés et les questions transversales sur lesquels les propositions de recherche doivent porter. Ce que PMNT finance. Réduction de l'usage nocif de l'alcool. Analyses situationnelles du niveau de mise en œuvre des mesures de lutte contre l'usage nocif de l'alcool (contrôle exercé sur.

  8. 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)

  9. 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)

  10. Fuel cell power plant - a proposal for analysis of the economical viability of the implantation; Usina a celula de combustivel - uma proposta para analise da viabilidade economica de sua implantacao

    Energy Technology Data Exchange (ETDEWEB)

    Amendola, Alexandre Gomes; Rocha, Mauro Cesar da [ELETROBRAS, Rio de Janeiro, RJ (Brazil)

    2000-07-01

    The present work presents a methodology which allows a fast analyses of the economic viability of the implantation of fuel cell power plant. The paper also presents the practical application for two important concessionaires.

  11. 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)

  12. 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)

  13. 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)

  14. 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)

  15. Conversion of cycle Diesel engines to Otto aiming the methane utilization as alternative fuel; Conversao de motores do ciclo diesel para Otto visando a utilizacao do metano como combustivel alternativo

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J F; Venanzi, D [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia

    1988-12-31

    A diesel engine was converted in Otto engine for use methane as fuel, by modifications on compression ratio and on the induction system, and inclusion of a spark ignition system. The performance of dynamometer essays results in both cycles are compared and presented in overlapped curves. (author). 5 refs., 2 figs., 2 tabs

  16. 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)

  17. 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)

  18. 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)

  19. 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)

  20. 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)

  1. 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)

  2. 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)

    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)

  3. 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)

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. 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)

  9. 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)

  10. 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)

  11. Synthesis of modified calcium aluminate with lanthanum manganite (LSM) for possible use in solid oxide fuel cell (SOFC); Sintese de aluminato de calcio modificado com manganita de lantanio (LSM) para possivel utilizacao em celula combustivel de oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, F.C.T.; Jurado, J.; Sousa, V.C. de, E-mail: faili.cintia@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Departamento de Materiais; Cava, S.S. [Universidade Federal de Pelotas, RS (Brazil)

    2016-07-01

    The fuel cells solid oxide (SOFC) is made up of three basic elements: two electrodes, the anode and cathode and a conductive electrolyte ions. The objective of this work consists of calcium aluminate synthesis modified LSM in a 1: 1 by combustion synthesis method with a view to its use as a cathode in SOFC. The characterization of the post was carried out by the methods of XRD, TEM and EIS. After heat treatment at 1200°C/4 hours it was possible to obtain Ca0.5Sr1.5MnO4 and CaMnO2.56 phases. The material showed a semiconductor characteristics because with increasing temperature the electrical resistance value tends to decrease obtaining electrical conductivity greater than 10-6S / cm featuring an extrinsic semiconductor with an activation energy of 0.12. Therefore, with an activation energy value within the range of materials used for a SOFC cathodes. (author)

  12. 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)

  13. 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)

  14. 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)

  15. 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)

  16. 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)

  17. 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)

  18. 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)

  19. Contribution to fuel depletion study in PWR type reactors, reactor core with three and four regions of enrichment; Contribuicao ao estudo da evolucao da composicao do combustivel em reatores tipo PWR nucleos a tres e a quatro regioes de enriquecimento

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M C.C.

    1977-03-01

    The main methods for calculation of fuel depletion are studied and some approaches to do it are mentioned; the LEOPARD Code is described and full details are given for each subroutine, flow charts are included; the method given by the code for calculation of fuel depletion is described; some imperfections from the IPR`s version are listed, and corrected, for instance: the method for burn-up calculation of heavy isotopes; the results of calculations for a reference reactor based on data of the Preliminary Safety Analysis Report (PSAR) for Angra I Nuclear Power Plant are presented and discussed. (author).

  20. 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)

  1. Increase of thermal conductivity of uranium dioxide nuclear fuel pellets with beryllium oxide addition; Condutividade termica de pastilhas de combustivel nuclear de UO{sub 2}-BeO nas temperaturas de 25 deg C e 100 deg C

    Energy Technology Data Exchange (ETDEWEB)

    Camarano, D.M.; Mansur, F.A.; Santos, A.M.M. dos; Ferraz, W.B., E-mail: dmc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTM/CNEN-MG), Belo Horizonte, MG (Brazil)

    2016-07-01

    The UO{sub 2} fuel is one of the most used nuclear fuel in thermal reactors and has many advantages such as high melting point, chemical compatibility with cladding, etc. However, its thermal conductivity is relatively low, which leads to a premature degradation of the fuel pellets due to a high radial temperature gradient during reactor operation. An alternative to avoid this problem is to increase the thermal conductivity of the fuel pellets, by adding beryllium oxide (BeO). Pellets of UO{sub 2} and UO{sub 2}-BeO were obtained from a homogenized mixture of powders of UO{sub 2} and BeO, containing 2% and 3% by weight of BeO and sintering at 1750 °C for 3 h under H{sub 2} atmosphere after uniaxial pressing at 400 MPa. The pellet densities were obtained by xylol penetration-immersion method and the thermal diffusivity, specific heat and thermal conductivity were determined according to ASTM E-1461 at room temperature (25 deg C) and 100 deg C. The thermal diffusivity measurements were carried out employing the laser flash method. The thermal conductivity obtained at 25 deg C showed an increase with the addition of 2% and 3% of BeO corresponding to 19% and 28%, respectively. As for the measurements carried out at 100 deg C, there was an increase in the thermal conductivity for the same BeO contents of 20% and 31%. These values as a percentage of increased conductivity were obtained in relation to the UO{sub 2} pellets. (author)

  2. 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)

  3. Acid pre-hydrolysis of biomass as a preparation process for its utilization as thermoelectric power plants fuel; Pre-hidrolise acida da biomassa como preparacao de combustivel para termoeletrica

    Energy Technology Data Exchange (ETDEWEB)

    Pinatti, D G; Resende, R L [Fundacao de Tecnologia Industrial (FTI), Lorena, SP (Brazil)

    1991-12-31

    It is described a process of production of celulignin from biomass through acid pre-hydrolysis in continuous reactor made of advanced materials such as niobium, titanium and monel. The celulignin is a fuel of 28.50 MJ/kg of heating power. The utilization of this technology together with eucalyptus reforestation by vegetative propagation and high efficiency thermoelectric plant (triple cycle of steam turbine, gas turbine and MHD electrical generation) allow electric power production with competitive cost when compared to hydroelectric power. (author). 1 ref. 5 figs., 2 tabs

  4. 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)

  5. 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)

  6. 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)

  7. 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)

  8. Fuel performance computer code simulation of steady-state and transient regimes of the stainless steel fuel rods; Simulacao com programas computacionais de desempenho do combustivel em regimes permanente e transiente de varetas combustiveis de aco inoxidavel austenitico

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Daniel de Souza

    2014-07-01

    The immediate cause of the accident at the Fukushima Daiichi nuclear plant in March 2011 was the meltdown of the reactor core. During this process, the zirconium cladding of the fuel reacts with water, producing a large amount of hydrogen. This hydrogen, combined with volatile radioactive materials leaked from the containment vessel and entered the building of the reactor, resulting in explosions. In the past, stainless steel was used as the coating in many pressurized water reactors (PWR) under irradiation and their performance was excellent, however, the stainless steel was replaced by a zirconium-based alloy as a coating material mainly due to its lower section shock-absorbing neutrons. Today, the stainless steel finish appears again as a possible solution for security issues related to the explosion and hydrogen production. The objective of this thesis is to discuss the performance under irradiation of fuel rods using stainless steel as a coating material. The results showed that stainless steel rods exhibit lower temperatures and higher fuel pellet width of the gap - coating the coated rods Zircaloy and this gap does not close during the irradiation. The thermal performance of the two fuel rods is very similar, and the penalty of increased absorption of neutrons due to the use of stainless steel can be offset by the combination of a small increase in the enrichment of U- 235 and changes in the size of the spacing between the fuel rods. (author)

  9. 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)

  10. 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.

  11. 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)

  12. 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)

  13. 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)

  14. Development of materials for use in solid oxid fuel cells anodes using renewable fuels in direct operation; Desenvolvimento de materiais ceramicos aplicados em anodos de celulas a combustivel de oxidos solidos para operacao direta com combustiveis renovaveis

    Energy Technology Data Exchange (ETDEWEB)

    Lima, D.B.P.L. de [Instituto Federal do Parana (IFPR), PR (Brazil); Florio, D.Z. de; Bezerra, M.E.O., E-mail: daniela.bianchi@ifpr.edu.br [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2016-07-01

    Fuel cells produce electrical current from the electrochemical combustion of a gas or liquid (H2, CH4, C2H5OH, CH3OH, etc.) inserted into the anode cell. An important class of fuel cells is the SOFC (Solid Oxide Cell Fuel). It has a ceramic electrolyte that transports protons (H +) or O-2 ions and operating at high temperatures (500-1000 °C) and mixed conductive electrodes (ionic and electronic) ceramics or cermets. This work aims to develop anodes for fuel cells of solid oxide (SOFC) in order to direct operations with renewable fuels and strategic for the country (such as bioethanol and biogas). In this context, it becomes important to study in relation to the ceramic materials, especially those that must be used in high temperatures. Some types of double perovskites such as Sr2MgMoO6 (or simply SMMO) have been used as anodes in SOFC. In this study were synthesized by the polymeric precursor method, analyzed and characterized different ceramic samples of families SMMO, doped with Nb, this is: Sr2 (MgMo)1-xNbxO6 with 0 ≤ x ≤ 0.2. The materials produced were characterized by various techniques such as, thermal analysis, X-ray diffraction and scanning electron microscopy, and electrical properties determined by dc and ac measurements in a wide range of temperature, frequency and partial pressure of oxygen. The results of this work will contribute to a better understanding of advanced ceramic properties with mixed driving (electronic and ionic) and contribute to the advancement of SOFC technology operating directly with renewable fuels. (author)

  15. Analysis process and the dimensioning direction of the Powertrain project for the best vehicle fuel consumption; Processo de analise e direcionamento de projeto de powertrain para o melhor consumo de combustivel veicular

    Energy Technology Data Exchange (ETDEWEB)

    Rupcic, Jorge Radosevic [Fiat GM Powertrain Ltda. (Brazil); Massarani, Marcelo [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    2006-07-01

    This paper presents the viability analysis methodology of powertrain project aiming the improvement the vehicle fuel consumption. The object of this work is the definition which powertrains architecture results in the best vehicle fuel consumption and to know the impact on the enterprise, considering to offer flexibility for allowing the successive increment when new technologies are required without high resources and yet offering performance gains that maintain the vehicle on competitive level and well accepted by the customers.

  16. 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)

  17. 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)

  18. Microstructural characterization of composite cobaltite and lanthanum-based ceria for use as fuel cell cathodes; Caracterizacao microestrutural de compositos a base de cobaltita de lantanio e ceria para aplicacao como catodos de celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, E.R.T.; Nascimento, R.M.; Miranda, A.C. de; Lima, A.M. de, E-mail: erickssonrtr@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Macedo, D.A. [Universidade Federal da Paraiba (UFPB), PB (brazil)

    2016-07-01

    Fuel cells are devices that convert chemical energy into electricity via redox reactions. In this work, the lanthanum cobaltite doped with strontium and iron (La{sub 0,6}Sr{sub 0,4}Co{sub 0,2}Fe{sub 0,8}O{sub 3} - LSCF) a traditional cathodes material of the fuel cell was mixed with an electrolyte material (composite) to the base ceria doped with gadolinia and a eutectic mixture of lithium carbonates and sodium (CGO-NLC). The powders of LSCF and CGO-NLC were obtained by the citrate method and mixed to obtain a composite cathode. Samples obtained by uniaxial pressure between 5 and 10 MPa were sintered at 1100°C and investigated by X-ray diffraction, scanning electron microscopy and micro hardness test. A symmetric cell cathode / electrolyte / cathode, obtained by co-pressing and co-sintering was investigated by electron microscopy. The results indicated that the composite is chemically stable up to the sintering temperature used. The hardness ranged between 51 and 227 HV. (author)

  19. 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)

  20. 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)