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Sample records for combustible verdades sobre

  1. A verdade como um problema epistemológico

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    Geilson Fernandes de Oliveira

    2016-07-01

    Full Text Available O presente ensaio é fruto das discussões realizadas durante a disciplina de mestrado Epistemologia das Ciências Sociais e Humanas. Aqui, objetivamos discutir sobre a verdade como um problema epistemológico. Assim, a partir do conceitual teórico utilizado durante a disciplina, entre os quais destacamos Michel Foucault, Norbert Elias, Friedrich Nietzsche e Pierre Bourdieu, tecemos considerações sobre as concepções de verdade no pensamento social contemporâneo, bem como no que diz respeito as rupturas que favoreceram a emergência de seu estado corrente – concepção da verdade como produção social e histórica. Consonante a esta discussão, realizamos ainda uma breve discussão sobre as relações de poder e saber que favorecem a constituição da verdade.

  2. IMPROPRIEDADE DOS PRINCÍPIOS DA VERDADE MATERIAL E DA VERDADE FORMAL: UMA ANÁLISE FILOSÓFICA SOBRE A VERDADE ALCANÇÁVEL PELO DIREITO

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    Patrícia de Almeida Cardoso

    2010-08-01

    Full Text Available A doutrina relaciona à atividade probatória os princípios da verdade material e da verdade formal. Entretanto, o presente trabalho tem por escopo demonstrar a impropriedade desta divisão principiológica. Transportando-se para o Direito o conceito de verdade para a Filosofia, em destaque à Escola do Pragmatismo e do Neopragmatismo, bem como, apresentando-se o conjunto de limitações intrínsecas à natureza humana e criadas pelo ordenamento jurídico, busca-se evidenciar a intangibilidade da verdade pelo sistema jusprocessual e individualizar o que, de fato, é retratado pelas sentenças penal e civil.

  3. Verdade pragmática

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    Jair Minoro Abe

    1991-08-01

    Full Text Available Como se sabe existem, pelo menos, quatro teorias de verdade que se evidenciam de relevância para o filósofo que se ocupa da Teoria da Ciência: 1 a Teoria da Correspondência, particularmente, na forma que lhe confiriu A. Tarski; 2 a Teoria da Coerência; 3 a Teoria Pragmática; e 4 a Teoria da Eliminação da Verdade (ou definibilidade da verdade. Neste artigo, de caráter expositivo, se apresenta um apanhado geral de alguns desenvolvimentos técnicos que têm sido feitos nos adimos anos sobre a verdade pragmática, que também é chamada de quase verdade.There are at least four theories of truth that are relevant for philosophers of science theory: 1 Theory of Correspondence, particulary, in the way it was proposed by A. Tarski; 2 Theory of Coherence; 3 Pragmatic Theory; and 4 Theory of the Truth Elimination (or definibility of truth. In this expositor article, it is presented a general aspect of some technical developments that have been done recently about the Pragmatic Truth, which is also called " Quasi-Truth".

  4. Progresso Científico e Verdade em Popper

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    Elizabeth de Assis Dias

    2015-08-01

    Full Text Available O presente trabalho pretende mostrar que, para solucionar a questão da possibilidade do progresso científico, Popper precisou introduzir a ideia de verdade no âmbito de sua teoria da ciência. Essa concepção de progresso, em termos da noção de verdade, só será delineada na obra Conjectura e refutações (1963, pois a ideia de que o alvo da ciência é a verdade ainda não aparece teorizada em suas primeiras obras. Quando Popper escreveu sua A lógica da pesquisa científica(1934, a ciência era definida em termos de regras lógico-metodológicas e não de suas metas. O avanço científico é concebido a partir das noções de testabilidade e de corroborabilidade das teorias, exigências lógicometodológicas para que uma teoria seja considerada como científica. Popper não relacionou a questão do progresso científico à noção de verdade, nessa obra, porque, quando a escreveu, não dispunha de uma consistente teoria da verdade. Foi somente após Tarski ter escrito seu artigo sobre a concepção semântica da verdade que Popper, tendo por base essa concepção de verdade, pôde complementar as suas teses sobre o progresso da ciência, expostas em sua A lógica da pesquisa cientifica, com uma teoria acerca do conteúdo de verdade e da aproximação da verdade.

  5. La verdad histórica: una verdad que se establece y legitima desde el punto de vista de las victimas

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    Tatiana Rincón-Covelli

    2010-03-01

    Full Text Available Aproximarse al concepto de verdad no es una tarea fácil. Supone, entre otras cosas, asumir e incursionar en la basta discusión que existe sobre el concepto. Sin embargo, lo que pretendo en este escrito es algo muy modesto: explorar una aproximación a un concepto particular y muy situado de verdad: el concepto de verdad histórica, inserto en el contexto de sentido que brindan las sentencias de los tribunales internacionales de derechos humanos, y, más concretamente, las sentencias de la Corte Interamericana de Derechos Humanos. Por tanto, no pretendo incursionar en la discusión más amplia de lo que es la verdad, sino sólo aproximarme a un concepto de verdad que opera en un contexto normativo estrictamente acotado. Ese contexto determina el uso que se hace del concepto.

  6. La verdad

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    Clavijo Gloria

    1991-12-01

    Full Text Available

    Los valores éticos no consisten en obedecer a una norma externa impuesta, ni siquiera a una racionalidad interna formal autónoma o a una creación arbitraria del universo axiológico, sino que son una actitud vivida de escucha, de respeto, de amor hacia el sentido sagrado y misterioso de la propia vida y de los otros. Por esto, en el siguiente trabajo se pretende en primer término hacer una reflexión sobre un valor ético fundamental en el desempeño profesional de la enfermera: la verdad. Luego se relaciona este valor con un dilema ético encontrado en la práctica diaria y finalmente se dan algunas conclusiones que motiven a las enfermeras a buscar la verdad ya tenerla como piedra angular en su construcción personal y profesional.

  7. Verdades e produção de subjetividades: um estudo sobre mulheres bíblicas no discurso publicitário

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    Denise Gabriel Witzel

    2012-01-01

    Full Text Available A partir del concepto de verdad, tal como es formulado en la obra de Michel Foucault , más precisamente a partir de la diferencia que el !lósofo propone en su genealogía entre verdad/demostranción, valorada por la tradicional perspectiva filosófico-cientifíca, y verdad/acontecimiento, este estudio propone dar visibilidad a la actualización de enunciados que, en el universo publicitario, legitiman saberes sobre el ser mujer. Son enunciados que dan destaque a dos famosos modelos de mujeres bíblicas, exaltados hace siglos por toda una tradición cristiana: Eva (emblema del pecado y de la perdición y la Virgen María (símbolo de la virtud y salvación. Al focalizar la reconstrucción de los juegos de verdad forjados en la noche de los tiempos, con relación al ser mujer, los análisis dan visibilidad a las condiciones históricas de emergencia de las imágenes de aquellas mujeres, a la ley de coexistencia de esos enunciados con otros y a los principios segundo los cuales subsisten, aunque reinventados, hasta los días de hoy.

  8. Verdade e método em Francis Bacon

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    Secco, Márcio

    2004-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em Filosofia. Estudo sobre o método e o conceito de verdade defendido por Francis Bacon, sendo nossos principais objetivos nesse trabalho: a) esclarecer algumas questões relativas ao método baconiano, principalmente no que se refere ao uso de hipóteses; b) apresentar uma interpretação falibilista da teoria de Francis Bacon, mostrando que a verdade e a utilidade...

  9. Nuestra verdad sobre SYNTAX

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    Manuel Carnero-Alcázar

    2017-01-01

    Full Text Available El ensayo clínico Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX ha marcado un hito en la historia de la revascularización miocárdica. El análisis del objetivo primario demostró que la cirugía era capaz de reducir el riesgo de eventos cardiovasculares mayores frente al intervencionismo coronario con stents recubiertos en pacientes con enfermedad multivaso o del tronco coronario. Sin embargo, la interpretación de los análisis de subgrupos y eventos secundarios ha servido para justificar la revascularización con stents recubiertos en grupos seleccionados de enfermos. Las conclusiones de SYNTAX han tenido un gran y discutido impacto en las guías de revascularización miocárdica europeas y en la práctica clínica diaria, forzando nuevas indicaciones, fomentando la reunión del Heart Team y poniendo a nuestro alcance nuevas herramientas como SYNTAX score. Los cirujanos cardiacos y cardiólogos hemos asumido todos estos cambios sin apenas crítica. Pero, ¿cuánta verdad irrefutable hay en SYNTAX?

  10. Sobre pluralismo, verdade e tolerância: diálogos epistemológicos e éticos para uma educação intercultural

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    Marcelo Andrade

    2011-12-01

    Full Text Available Multiculturalismo e interculturalidade, ainda que guardem distinções, são conceitos que têm conquistado grande espaço no discurso educacional. Há uma série de pesquisas que os aproximam do campo do currículo, da prática pedagógica e da educação popular. Este trabalho, por sua vez, visa a contribuir com o debate no campo dos fundamentos da educação. Nesse sentido, o objetivo foi eleger duas abordagens teóricas e trazê-las para o diálogo sobre questões epistemológicas e éticas, a fim de ressignificar o debate sobre a perspectiva intercultural em educação, privilegiando os conceitos de verdade, pluralismo e tolerância. Assim, foi privilegiado o diálogo com Karl Popper e Noberto Bobbio. Com o primeiro, buscou-se entender como a concepção de verdade pode ajudar a entender uma proposta de educação intercultural. Com o segundo, buscou-se avançar das questões epistemológicas para os desafios éticos sobre o pluralismo e a tolerância na prática pedagógica.

  11. CERTEZA Y VERDAD EN EL DERECHO

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    Agustín Luna Serrano

    2012-12-01

    Full Text Available I. LA POSIBLE ESCISIÓN ENTRE CERTEZA Y VERDAD: 1. Unas referencias doctrinales como punto de partida.- 2. Las certezas públicas de las verdades oficiales.- 3. Consistencia y variedad de las verdades oficiales.- 4. La justificada asunción instrumental de las verdades oficiales. II. LA CERTEZA DE LAS VERDADES OFICIALES: 5. Breves indicaciones taxonómicas.- 6. Las verdades judiciales revestidas de autoridad.- 7. Las verdades presuntas.- 8. Las verdades presupuestas.- 9. Las verdades aparentes.- 10. Las verdades simuladas.- 11. Las verdades fiduciarias.- 12. Las verdades ficticias.- 13. Las verdades falsas. III. APRECIACIONES CONCLUSIVAS: 14. La razonable divergencia entre certeza y verdad.- 15. Colofón.

  12. O amor e a verdade: Investigações em Santo Agostinho e Kierkegaard

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    Gabriel Kafure da Rocha

    2017-03-01

    Full Text Available São notórios os diversos pensamentos sobre o amor e sua inquietude pela verdade, sentimentos estes que são expostos pelos seres humanos como requisitos para encontrar a própria felicidade. Com isso, exploramos as visões de S. Agostinho e Kierkegaard que estabelecem para o real encontro do pleno amor estabelecido nos homens, porém confundidos por seus princípios ilusórios que acabaram se distanciando do verdadeiro sentido da verdade.

  13. La primera verdad inconveniente

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    Michel ODENT

    2010-12-01

    Full Text Available A partir de una perspectiva fisiológica para analizar la evolución de la humanidad desde los inicios hasta los días actuales, el autor identifica la especie “Homo superpredador” como prevalente en la actualidad, que presenta gran potencial de agresión y dificultad para la convivencia. A medida que las estrategias básicas de sobrevivencia de los grupos humanos son la dominación de la naturaleza y de otros grupos humanos, las sociedades exitosas son las que transmitirán de generación en generación A primeira verdade inconveniente1 The prime inconvenient truth La primera verdad inconveniente REFLEXÕES SOBRE HUMANIZAÇÃO E A REALIDADE DOS SERVIÇOS REFLECTIONS ON HUMANIZATION AND THE REALITY OF HEALTH SERVICES REFLEXIONES SOBRE LA HUMANIZACIÓN Y LA REALIDAD DE LOS SERVICIOS 62 // Rev Tempus Actas Saúde Col creencias y rituales que amplifican el potencial de agresión y moderan la capacidad de amar. Considerando los aspectos emergentes de expresión génica y períodos críticos para la interacción génica con el medio ambiente, el autor consigue asociar las características del Homo superpredador con la forma por el cual los bebés nacen. En una época en que es vital reflexionar sobre la sobrevivencia de la humanidad, mas que en la de grupos específicos, el autor pondera se sería utópico inducir deliberada y conscientemente la llegada del Homo Ecologicus como una nueva variedad de especie humana, a través de un proceso posible de modulación epigenética. Este objetivo implica en un cuestionamiento: Será la fisiología moderna suficientemente poderosa para redescubrir las necesidades básicas de la mujer en el trabajo de parto y de su bebé, a pesar de siglos de socialización del parto y nacimiento y del condicionamiento cultural profundamente arraigado?

  14. Tomar la palabra: el acontecimiento de la verdad en el testimonio

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    Iván Hernández

    2016-01-01

    Full Text Available La cuestión de la verdad ocupa un lugar de gran importancia en la consolidación de los procesos de negociación política que conducen al fin de la guerra y a la reconstrucción del lazo social en el posconflicto. En ese contexto, el testimonio de las víctimas corre el riesgo de terminar siendo instrumentalizado, por los dispositivos jurídicos y los archivos de la memoria histórica, en la empresa política del establecimiento de una verdad conveniente. Sin embargo, el psicoanálisis advierte sobre esa dimensión de acontecimiento de la verdad, que impugna al discurso en su pretensión de domesticarla, de hacerla dócil a los límites que él mismo le señala. En tanto que el testimonio supone una toma de la palabra, se hace necesario preguntarse por el lugar del sujeto que allí adviene y la verdad que le concierne.

  15. La desaparición forzada: una verdad caleidoscópica

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    Cristian Jesús Palma Florián

    2016-01-01

    Full Text Available La violencia de la desaparición forzada genera efectos en el lazo social y en la colectividad, al igual que en la escena subjetiva donde se inscribe como vacío en el orden simbólico. En el trabajo sobre el duelo que concierne a los desaparecidos es fundamental el lugar de la búsqueda de la verdad, la cual opera como pulsión de saber y como causa de goce. Este artículo se propone ver cómo en el contexto colombiano, específicamente en los escenarios transicionales que proponen la Ley de Justicia y Paz y la Ley de Víctimas, se estructuran espacios de producción de la verdad que posibilitan o restringen su búsqueda por parte de los familiares de las víctimas de desaparición forzada, haciendo un seguimiento al tránsito que se da desde las escenas públicas colectivas, a través de la verdad judicial y la verdad histórica, hacia la escena subjetiva donde se debe resolver el duelo.

  16. Transformando 'verdades abstratas' em 'verdades concretas': uma análise sobre a metodologia econômica de John Stuart Mill

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    Laura Valladão de Mattos

    2004-03-01

    Full Text Available Visa-se explicar como se daria, segundo Mill, a transformação das 'verdades abstratas' da ciência da economia política - engendradas a partir da utilização da abstração 'homem econômico' - em 'verdades concretas' passíveis de serem utilizadas para previsão dos eventos e como base para a formulação de política econômica. Argumenta-se que seria necessário não só 'humanizar' o 'homem econômico', levando em conta motivações humanas que são propositadamente excluídas pela ciência da economia política, como também considerar peculiaridades institucionais de cada caso. Conclui-se que, apesar do sucesso de Mill em transformar verdades abstratas em concretas, os seus escritos metodológicos são por demais vagos e insuficientes para nos servir de guia nesta importante questão.We aim at explaining Mill's view on the transformation of the 'abstract truths' of the science of political economy - obtained by using the 'economic man' abstraction - in 'concrete truths', which could be used both to predict events and as support for policy decisions. We argue that it would not only be necessary to 'humanize' the 'economic man' by taking in account several human motivations that are not considered by the science of political economy, but also to take in account the institutional peculiarities of each case. We conclude that despite Mill's success on his attempts to transform 'abstract' in 'concrete' truths, his methodological advices are too vague and insufficient to guide us in this important issue.

  17. La verdad, el liberalismo y la economía

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    María Teresa Lopera

    1993-07-01

    Full Text Available Al reflexionar a la luz de las críticas de Karl Popper al racionalismo y al empirismo, surgen naturalmente contrastes de interés para la ciencia económica como un discurso liberal con una particular relación con el asunto de la verdad del conocimiento. Este artículo explora algunas consecuencias de estos aspectos sobre el porvenir de la ciencia económica.

  18. Excertos sobre o sedentarismo

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    Palma,Alexandre; Vilaça,Murilo Mariano; Assis,Monique Ribeiro de

    2014-01-01

    O sedentarismo tem sido tratado como algo perfeitamente determinável, objetivo e, portanto, que pode ser apreendido. Por outro lado, o conceito de sedentarismo ainda permanece questionável e, por conseguinte, os instrumentos mostram-se inconsistentes. Neste sentido, o objetivo do presente estudo foi mostrar que diferentes discursos de verdade vêm concorrendo por esse conceito, o que nos motiva a pensar qual é a verdade ou, até mesmo, se há alguma verdade sobre ele. Após apresentarmos diferent...

  19. Verdade e diferença no pensamento de Michel Foucault

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    Cesar Candiotto

    2007-01-01

    Full Text Available O presente artigo versará sobre as articulações entre verdade e história no pensamento de Michel Foucault, e seu distanciamento da concepção originária e universalista de verdade. Acontecimento e diferença constituem conceitos decisivos para situar sua demarcação no domínio de estudo das ciências humanas, especialmente em seu primeiro grande livro, História da loucura na idade clássica.The paper deals with the articulation between truth and history in Michel Foucault's thought, and their separation from the originary and universal concept of truth. Event and difference constitute decisive concepts to situate his demarcation in the study domains of human sciences, especially in his first great book Madness and Civilization: A History of Insanity in the Age of Reason.

  20. Verdad por definición

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    Garrido Garrido, Julián

    1997-01-01

    Not available.La verdad por definición es un tipo peculiar de verdad científica, distinguible de las verdades lógicas, matemáticas y empíricas. La definición, por su parte, designa diversos procedimientos de asignación de significado, cuyas diferencias exigen una adjetivación cuidadosa: definiciones ostensivas y operacionales, definiciones de diccionario y definiciones teóricas. Pero sólo las del último tipo son verdaderas por definición. En el presente artículo se precisa el concepto formal ...

  1. VERDADE, VERDADE HISTÓRICA E REGIMES DITATORIAIS: O DIREITO FUNDAMENTAL À VERDADE NOS PROCESSOS DE TRANSIÇÃO DE ESTADOS DE EXCEÇÃO PARA ESTADOS DEMOCRÁTICOS

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    Pereira, Gabrielle Tatith

    2012-01-01

    RESUMOEste artigo tem como objetivo o estudo do direito à verdade como valor fundamental da democracia e como etapa necessária da justiça reparadora nos processos de transição de estados de exceção para estados democráticos. Pretende-se demonstrar que há uma relação necessária entre a democracia, enquanto espaço livre e politicamente autônomo de participação, e a construção da verdade. Nesse contexto, ressalta-se a importância das Comissões da Verdade como instrumentos de construção da verdad...

  2. Nossas Verdades, Nossas Criações

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    Fernanda Machado de Bulhões

    2010-10-01

    Full Text Available Este breve ensaio tem como objetivo apresentar, em linhas gerais, alguns aspectos da critica de Nietzsche à nocáo de verdade. Partindo do principio de que a razáo náo é uma fiel representaçáo do estatuto ontologico, ja que o pensamento racional é uma instancia que nasce das relaçáoes de forcas instintivas, para Nietzsche a racionalidade náo descobre a verdade, ela inventa uma: a sua verdade. Assim sendo, por mais que ofereca demonstraçoes logicas, a razáo náo é capaz de sustentar uma verdade universal, mesmo porque como poderia uma coisa ser sustentada por ela propria?

  3. A produção analógica da verdade no processo penal: desvelando a reconstrução narrativa dos rastros do passado

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    Salah Hassan Khaled Jr.

    2015-03-01

    Full Text Available Este artigo pretende discutir o regime da verdade do processo penal, problematizando o conceito de verdade correspondente (real, material, substancial e relativa a partir de uma epistemologia da passeidade, que procura atentar para a complexidade do tempo escoado que é o referencial cognitivo do processo penal: o conhecimento sobre o passado é construído a partir de rastros, conformando uma verdade analógica que é produzida narrativamente. Com isso, visa o rompimento do paradigma da verdade correspondente utilizada como sustentáculo da busca pela verdade real pelo juiz, resultando o famigerado ativismo judicial, maculando a estrutura acusatória do devido processo legal. A análise pretende superar o isolacionismo do discurso jurídico, atualmente deficitário diante dos novos paradigmas dos discursos dos demais campos do saber.

  4. El problema de la verdad y la alhqeia

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    Roberto Estrada Olguín

    2009-01-01

    ón que denominamos justificacionista incluimos las “teorías de la verdad”, las cuales han proliferado en estos tiempos porque ellas han adoptado la misma “actitud” y han proporcionado la misma “respuesta” ante el escepticismo. Para la perspectiva ontológica expondremos el pensamiento de Heidegger sobre el tema de la verdad, porque en él encontramos el planteamiento del asunto adoptando una “actitud” y proporcionando una “respuesta” que no está dirigida a la búsqueda de una justificación. Además, que esta perspectiva es excluida de las teorías de la verdad, por lo cual su análisis es necesario para determinar su pertinencia en el problema de la verdad. Estas dos orientaciones, a mi juicio, proporcionan un bosquejo mínimo suficiente del problema de la verdad.

  5. Del sujeto de la verdad a la verdad del sujeto/From the subject of truth to the truth of the subject

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    Eric Ferdinando Passone

    2008-06-01

    Full Text Available Este artículo pretende introducir el análisis de los discursos, a partir de cuestionamientos sobre la verdad del sujeto del deseo y apuntar algunas de sus consecuencias, principalmente, en lo que respecta a la elaboración y diseño de políticas y programas educativos de atención y atendimiento infante-juvenil. Se aprovecha para presentar las dislocaciones del pensamiento de Jaques Lacan sobre la práctica psicoanalítica y la diferencia entre seguir los modelos y hacer de la diferencia un camino propio, la existencia. This essay aims at to introduce an analysis of discourses questioning about the truth of the subject’s desire, and also to point out some consequences, which are mainly in the elaboration and design of policies and educational programs attending to children. Furthermore, it’ll be presented Jack Lacan’s thought about psychoanalytic practice and the difference between following models and making own way for the existence, from its singularity.

  6. Em torno da questão da verdade (On the question of the truth - DOI: 10.5752/P.2175-5841.2012v10n25p12

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    Antonio Manzatto

    2012-03-01

    Full Text Available A questão sobre a verdade, se não for bem colocada, pode dificultar o encontro e o diálogo entre teologia e literatura. A elaboração da ficção não é necessariamente distanciamento da verdade, nem o discurso teológico é o único verdadeiro. A metafísica tradicional já afirmava o belo e o verdadeiro como transcendentais. Hoje, mesmo em ciências, debate-se sobre a compreensão da verdade uma vez que tal conceito não é simples nem unívoco. Reconhecendo que há diversas ordens de verdade e diferentes caminhos para atingi-la, o texto enfoca as distintas maneiras de se colocar o problema da verdade em literatura e em teologia, mas de maneira a facilitar um real diálogo entre elas mostrando, por uma rápida referência aos estudos bíblicos, que tal diálogo é possível e mesmo desejável. Ali, não há que se opor, por exemplo, a verdade histórica à verdade literária, que é aquela apresentada pelo texto, mas busca-se alcançar a “verdade de salvação”, aquela que vai se relacionar de maneira mais direta com a fé.Palavras-Chave: Verdade. Teologia e Literatura. Narração. Estética. História.  AbstractThe question about the truth becomes difficult the dialogue between theology and literature. The development of fiction does not mean a separation of the truth.  In turn, the theological discourse is not the only true. Traditional metaphysics has already affirmed the beautiful and the true as a transcendental. Nowadays, even in science, there is a debate about the understanding of the truth since this concept is not simple, nor univocal. The text recognizes that there are several orders of truth and also different ways to achieve it. In other words, the paper looks at different ways of putting the question of truth in literature and in theology, aiming to facilitate the dialogue between them.Keywords: Truth. Theology and Literature. Narration. Aesthetics. History.- DOI: 10.5752/P.2175-5841.2012v10n25p12

  7. Chile, 40 Años de exigencias de verdad y justicia

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    Boris Hau

    2018-01-01

    Full Text Available Tras el regreso a la democracia en Chile, las políticas de justicia transicional iniciaron con la búsqueda de verdad, luego vinieron las políticas de reparación. Pero la justicia en Chile demoró en llegar: este proceso inició en 1998 con la interposición de la primera querella contra el exdictador Augusto Pinochet. En el año 2017 se cumplen 44 años del golpe militar, pero las consecuencias de las violaciones a los derechos humanos siguen estando vigentes. Cuatro décadas después, todavía se están investigando juicios de derechos humanos por el poder judicial. La Corte Suprema ha condenado a los principales responsables a penas de cárcel. En este trabajo se presenta el caso de Marcelo Concha, un joven militante comunista desaparecido en 1976. En 2016, sus familiares obtuvieron justicia al condenar la Corte Suprema a los responsables de este crimen, todos exagentes de la dictadura. Las políticas de verdad y justicia que se han realizado a 44 años de sucedidos los hechos son exigencia y requisito para una democracia consolidada que garantice un “nunca más” sobre esos hechos similares.

  8. «La verdad Oculta» (2015: una disputa médico?deportiva llevada al cine

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    Alejandro A. PENICHE PÉREZ

    2016-12-01

    Full Text Available La verdad oculta (2015 de Peter Landesman se trata de un drama deportivo, basado en hechos reales sobre la vida del famoso neuropatólogo forense, Dr. Bennet Omalu; cuyo personaje es interpretado por el actor Will Smith. Esta película narra los acontecimientos que condujeron al Dr. Omalu hacia el descubrimiento de una enfermedad neurodegenerativa progresiva, la cual nombró como Encefalopatía Traumática Crónica (ETC. Ésta enfermedad se manifiesta en los jugadores profesionales de fútbol americano, como consecuencia del constante número de colisiones que reciben los jugadores dentro del campo. Dicho descubrimiento generó disgusto a una de las corporaciones más poderosas y queridas del mundo, la National Football League (NFL situación que la condujo a tratar de desacreditar la información publicada por el Dr. Bennet Omalu, quien decidió correr el riesgo de enfrentarlos para dar a conocer la verdad.

  9. De “O Nome da Rosa” ao “O Código Da Vinci” verdade, mentira, autoritarismo e individualismo na disseminação da informação

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    Patrícia Zeni Marchiori

    2006-07-01

    Full Text Available Apresenta uma leitura de dois best sellers contemporâneos sob o ponto de vista da disseminação da informação. Discutem-se os conceitos de verdade, a busca da verdade, o acesso à informação, as motivações e critérios individuais que se sobrepõem à necessidade, validação e uso da informação. Considerando-se que o universo pessoal representa a fronteira do entendimento e da aceitação da informação como verdade, pelo menos três dimensões concorrem para o acesso à informação, e são afetadas pelas novas tecnologias. Tais tecnologias respaldam uma nova ordem de comunicação, cuja tendência crescente é a de transferir a responsabilidade plena sobre o processo de busca e uso da informação para o consumidor, acarretando leituras não convencionais sobre critérios de qualidade da informação e o surgimento de uma nova categoria de direitos civis: o direito intelectual.

  10. EL MOMENTO DE LA VERDAD (ROSI, 1965: fragmentos de España

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    Ludovico Longhi

    2016-08-01

    Full Text Available En 1965 Rosi realiza El momento de la verdad, largometraje semidocumental sobre la tauromaquia. El director italiano quería llevar a la pantalla el trágico lirismo de Muerte en la tarde (Hemingway, 1932. Sin embargo, algunos conocidos de la Suevia Film (coproductora española de su largometraje La sfida lo habían alertado sobre el escepticismo autóctono hacia los cronistas extranjeros. La afición taurina rechazaba la imagen de la corrida como simple espectáculo pintoresco. Este trabajo muestra la oportuna decisión de Rosi en investigar el fenómeno, apoyándose en la competencia de cineastas autóctonos como Beltrán, Portabella, Muñoz Suay y del torero Miguel Mateo “Miguelín”. El filme es internacionalmente reconocido como el más serio estudio sobre los aspectos socio-culturales del mundo de los toros.   PALABRAS CLAVE:  Momento de la verdad; Francesco Rosi; Tauromaquia; España.   ABSTRACT In 1965 Rosi made The Moment of Truth, a semi-documentary feature film about bullfighting. The Italian director wanted to bring to the screen the tragic lyricism of Death in the Afternoon (Hemingway, 1932. However, some acquaintances from Suevia Film (the Spanish co-producing company of his film La sfida alerted him about the skepticism in Spain towards the way foreigners regarded the fiesta. Bullfighting experts, in particular -they argued- were weary of the image given of their art as a simple popular entertainment. This article argues how Rosi managed to overcome the prejudices in his approach of the subject of The Moment of Truth with the help of Spanish filmmakers such as Beltran, Portabella, Muñoz Suay and the bullfighter Miguel Mateo “Miguelín”. The film is internationally recognized as the most serious study on the socio-cultural aspects of the bullfighting world.   KEYWORDS: Moment of truth; Francesco Rosi; Bullfighting; Spain.     RESUMO Em 1965 Rosi filmava “O momento da verdade”, filme semi-documentário sobre as

  11. A inteligência dos Futuros Contingentes: Interrogando G. W. Leibniz sobre Deus e a Verdade

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    Paulo Renato Jesus

    2016-03-01

    Full Text Available RESUMO: A presente investigação questiona a essência teo-lógica dos futuros contingentes. Para o efeito, analisa-se, primeiramente, a argumentação segundo a qual, sob certas condições lógicas, teológicas, ontológicas e cosmológicas antinecessitantes, detetadas por G. W. Leibniz (conciliando a posição de St. Agostinho com a de L. Molina e W. Ockham, a abertura contingente do futuro parece ser compatível com o regime das "verdades contingentes pré-determinadas", regime enquadrado teologicamente pelo princípio do "futuro melhor" ou do "único futuro verdadeiro". No entanto, os futuros contingentes incitam, com e contra Aristóteles, ao desenvolvimento de uma lógica temporal e plurivalente, ao modo de J. Łukasiewicz ou A. Prior. Essa lógica garante a abertura do futuro sem o oneroso custo metafísico da adesão a uma teo-lógica omnideterminante. A crítica do determinismo lógico, daí resultante, afigura-se mais coadunável com as condições pós-metafísicas inerentes à episteme agnósticacontemporânea, mas, nesse caso, a abertura do futuro implicaria uma profunda redefinição das próprias ideias e funções de "Deus", "matéria", "história" e "verdade".

  12. Mentira y Verdad en tres Novelas de Sergio Ramírez: Algunos Procedimientos de Verosimilitud

    OpenAIRE

    Rodríguez Sancho, Javier

    2013-01-01

    Con base en la narrativa del nicaragüense Sergio Ramírez, se efectúa un análisis sobre algunos procedimientos de verosimilitud utilizados por el escritor en tres de sus novelas: Tiempo de fulgor (1970); ¿Te dio miedo la sangre? (1977) y Un baile de máscaras (1995). La evaluación de los textos busca comprender los niveles en que el escritor hace uso de ciertos procedimientos de verosimilitud para contarnos algunas mentiras verdaderas como él mismo lo ha llamado, en su ensayo: Mentiras verdader...

  13. Impacto del uso de combustibles alternativos sobre la reactividad del clínker

    OpenAIRE

    Serrano-González, K.; Reyes-Valdez, A.; Chowaniec, O.

    2017-01-01

    El uso de combustibles alternativos en la industria cementera ha ido en incremento en las últimas décadas debido a su beneficio ecológico y económico. En línea con los esfuerzos enfocados en incrementar su uso, se han realizado distintos estudios enfocados en determinar su impacto potencial en la reactividad del clínker y en cómo pueden afectar sus propiedades físicas y mecánicas. Este trabajo estudia el efecto de cinco combustibles alternos sobre la reactividad de ocho muestras industriales ...

  14. Reflexões sobre o estatuto epistemológico das CSH: uma revisão das categorias verdade, sujeito e subjetividade

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    Pamella Rochelle Oliveira

    2015-12-01

    Full Text Available O presente ensaio teórico tem como objetivo discutir o conceito de verdade com ênfase nas obras de Friedrich Nietzsche e Michel Foucault, percebendo a temática como um dos conceitos chaves para se pensar o estatuto epistemológico das Ciências Sociais e Humanas (CSH na atualidade, já que o mesmo se faz intrinsicamente ligado a condições de possibilidades dadas, incidindo por sua vez na questão da produção de subjetividades, bem como do próprio sujeito, na medida em que estes são produzidos a partir e numa teia de relações invisíveis pautada em jogos de verdades e relações de poder. Para tanto, optamos num primeiro momento por realizar uma breve discussão acerca dos principais conflitos epistemológicos no campo das CSH, entre eles a antiga dualidade entre individuo x social, bem como a questão de causa e feito.

  15. Nietzsche y Freud ante el problema de la verdad

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    Leandro Drivet

    2016-01-01

    Full Text Available Este trabajo se propone reflexionar acerca del problema de la verdad en las obras de Friedrich Nietzsche y Sigmund Freud, a las que se considera estrechamente vinculadas. Esta perspectiva permitirá identificar el carácter específico de la “verdad”, cuyos vestigios detectaron ambos “psicólogos” transvaloradores; apreciar la doble valoración nietzscheana de la verdad, usualmente reducida a un rechazo unilateral; y repensar la pretensión de cientificidad del psicoanálisis, actualmente despreciada en nombre de una sospechosa reivindicación anticientífica. Se concluye con el postulado de que Nietzsche y Freud conciben a la verdad como una lucha contra las resistencias, lo que les conduce a fundar una nueva escucha.

  16. Memoria, verdad, nación y ciudadanía: algunas reflexiones sobre la Comisión de la Verdad y la Reconciliación en Sudáfrica

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    Mónica Inés Cejas

    2007-05-01

    Full Text Available En el presente artículo se yuxtapone “verdad” y memoria en el análisis del funcionamiento de la Comisión de la Verdad y la Reconciliación en Sudáfrica (1995-2001. Especialmente se exploran las “verdades” resultantes como producto de un proceso de redeinición de ciudadanía y nación (un proyecto político de construcción-reconstrucción nacional con cierta particularidad que conviene tener presente para poder pensarlas a la luz de similares experiencias en América Latina.

  17. Em Busca Da “Verdade Real”: Tortura e confissão no Brasil ontem e hoje

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    Joana Domingues Vargas

    2012-06-01

    Full Text Available Meu ponto de partida, neste ensaio, são as diferenças nas formas de investigação no Brasil e na Inglaterra analisadas com base em um relato de um viajante estrangeiro do século XIX contendo a visão do autor sobre a administração da justiça na cidade do Rio de Janeiro informada pela experiência de um furto. Nele procuro mostrar a permanência e persistência de uma crença epistemológica sobre o valor da confissão e da tortura que ainda informam as práticas de produção da verdade no Brasil contemporâneo. Uma das razões desta permanência é a investigação poder ser apresentada, nos relatos juridicamente orientados, como ela deveria ser e não como ela é realizada efetivamente. Este achado tem implicação para o debate atual sobre a necessidade de simplificação da investigação criminal no Brasil.

  18. A Comissão Nacional da Verdade e o caso dos protestantes durante a ditadura militar brasileira

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    Leandro Seawright Alonso

    2016-05-01

    Full Text Available Descrevi o ambiente político em que foi criada a Comissão Nacional da Verdade e, em seguida, abordei a criação do Grupo de Trabalho sobre o papel das igrejas na ditadura militar brasileira. Apresentei perspectivas sobre a “justiça de transição” e a consequente “frustração” sentida por parte da sociedade brasileira. Propus analisar o caso dos protestantes com base nas diferentes iniciativas do GT. Não obstante, analisei a documentação transcrita pela Presidência da República e as entrevistas de história oral contendo memórias de protestantes ortodoxos comunistas e heterodoxos anticomunistas no tocante à “justiça de transição” tardia e inconclusa na história republicana do Brasil.

  19. La universidad: una escuela al servicio de la verdad

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    Josu AHEDO RUIZ

    2016-05-01

    Full Text Available El artículo trata de abordar, en diálogo con diversos autores, dos cuestiones que son claves para la Institución universitaria y constituyen, a su vez, la clave para un adecuado desarrollo social. De una parte, señalar uno de los riesgos por los que atraviesa la Universidad que no es otro que la dejadez en la búsqueda de la verdad; pero otro riesgo no menor que debe afrontar tiene que ver con el olvido de la verdadera misión de la Universidad: la formación humanística. Un desarrollo adecuado de estas dos cuestiones, no cabe duda, que ayudará a afianzar la Institución Universitaria, básica para un desarrollo armónico y sostenible de la sociedad, eliminando la incertidumbre en quienes deben de llevar a cabo esta tarea. El ideal de la búsqueda de la verdad es lo que caracteriza a la Universidad desde su inicio. Sin embargo, la sociedad actual que aboga por el éxito fáctico puede acarrear un olvido de aquella y su sustitución por otras cuestiones relacionadas con las competencias. Por tanto, conviene no convertir la Universidad en una mera capacitación profesional, soslayando también la formación humanística que no debe separarse de la búsqueda de la verdad. Conservar el ideal universitario originario implica entender la actividad docente como un servicio. Es por ello que el profesor debe abogar por la formación de cada estudiante, tratando de ayudarle a descubrir aquello que de verdad le importa como persona. La Universidad actual no debe olvidar que la tarea docente de transmisión del saber superior requiere que este sea incrementado también por quienes reciben esta formación académica. Por tanto, la tarea del docente debe ser integradora de todos los saberes, evitando la fragmentación que puede conllevar perder el horizonte de la búsqueda de la verdad.

  20. Justicia, verdad y reparación en el proceso de paz en Colombia

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    Felipe Gómez Isa

    2014-12-01

    Full Text Available Uno de los principales retos del proceso de paz entre el Gobierno colombiano y las FARC-EP es la conciliación entre el logro de la paz y la garantía de los derechos de las víctimas a la justicia, a la verdad y a la reparación. El Congreso de Colombia aprobó en julio de 2012 el “Marco Jurídico para la Paz”, un conjunto de mecanismos de justicia transicional que pretenden facilitar las negociaciones, evitar la impunidad de los graves crímenes cometidos por los diferentes actores (guerrillas, grupos paramilitares y agentes estatales y otorgar garantías a las víctimas. Este Marco introduce los principios de priorización y selección para el ejercicio de la acción penal, es decir, define en qué supuestos y con qué criterios se pueden priorizar unos delitos respecto de otros e, incluso, si se puede centrar la investigación penal exclusivamente en los máximos responsables de crímenes de guerra, crímenes contra la humanidad y genocidio. Este es el umbral mínimo que cabe exigir tanto al Estado colombiano (y en particular a las fuerzas armadas como a los miembros del Secretariado de las FARC. El Marco Jurídico para la Paz también prevé la creación de una Comisión de la Verdad que arroje luz sobre los gravísimos crímenes cometidos en Colombia, y deja en manos del Estado instrumentos importantes en materia de flexibilización de la respuesta penal ante los crímenes cometidos por diferentes actores armados. Estos beneficios están condicionados a que los desmovilizados efectúen contribuciones significativas para una paz duradera, la verdad y para lograr la reparación de las víctimas.

  1. Daño, resentimiento y verdad. Sobre la réplica de Améry a Nietzsche

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    Julián MARRADES MILLET

    2009-11-01

    Full Text Available RESUMEN: En su Genealogía de la moral, Nietzsche situó el resentimiento del débil en el origen de la moralización de los valores genuinos del fuerte -entre ellos, la crueldad inherente a la afirmación de la vida- que transformó éstos en negativos. A esta idea del resentimiento como un mecanismo esencialmente distorsionador se opone Jean Améry, víctima de la violencia nazi, en Más allá de la culpa y la expiación (1966, donde reivindica su resentimiento hacia los verdugos y sus cómplices como un instrumento de verdad para exigirles el reconocimiento de su crimen y la negación de su condición de verdugos. El objetivo del artículo es reconstruir la trama conceptual en que se articula la divergencia entre Améry y Nietzsche, mostrando los diferentes compromisos ontológicos y epistemológicos sobre la moral que sustentan sus respectivas concepciones del resentimiento.ABSTRACT: In his Genealogy of Moráis Nietzsche located the weak's resentment on the origin of the moralization of the strong's genuine valúes -among them the inherent cruelty of life's strengthening- wich transformed in negative valúes. In Beyond guilt and expiation (1966 Jean Améry, a victim of nazi's violence, opposes to this idea of resentment as a mechanism essentially distortioning. He claims his resentment against executioners and their accomplices as an instrument of truth in view of demanding them the admission of their crime and the negation of their executioners' condition. The paper's aim is to reconstrue the conceptual plot in wich the divergence between Améry and Nietzsche is articulated, showing at the same time the different ontological and epistemological commitments on moral that hold up their conceptions of resentment.

  2. A verdade como um problema fundamental em Kant Kant on truth as a fundamental problem

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    Adriano Perin

    2010-01-01

    Full Text Available O principal ponto de desacordo sobre a abordagem kantiana do problema da verdade é se ela pode ser compreendida nos moldes da filosofia contemporânea como coerentista ou como correspondentista. Primando por uma consideração sistemática da argumentação de Kant em confronto com a literatura existente sobre o problema, este trabalho defende a segunda alternativa. Sustenta-se a tese de que a definição da verdade como a "concordância do conhecimento com o seu objeto" é cogente em todo o percurso do pensamento kantiano e que, nessa acepção, a verdade culmina por ser abordada não a partir de uma teoria estabelecida, mas como um problema cuja solução não pode ser dada nos limites da filosofia crítico-transcendental. Pondera-se, primeiramente, a literatura que situa Kant quer como coerentista quer como correspondentista e sistematiza-se a segunda alternativa em quatro grupos: a leitura ontológica, a leitura isomórfica, a leitura "consequencialista" e a leitura regulativa. Num segundo momento, em atenção ao período pré-crítico, argumenta-se que a alternativa coerentista deixa de se confirmar já nessa mesma época e que, na década de 1750, Kant descarta uma suposta teoria correspondentista isomórfica. Num último momento, considera-se a argumentação crítica e defende-se que a mesma concebe a verdade como um problema fundamental que não cabe ao tratamento de uma teoria correspondentista concebida de modo "consequencialista" ou regulativo.The main point of disagreement about Kant's approach of the problem of truth is whether it can be understood within the apparatus of contemporary philosophy as a coherence or a correspondence theory. By favoring a systematic consideration of Kant's argumentation in light of the available literature on the problem, this paper argues toward the latter alternative. It is sustained that the definition of truth as "the agreement of cognition with its object" is cogent throughout Kant's thought and

  3. VERDADE E FICÇÃO EM TEXTOS UTÓPICOS

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    Bento Itamar Borges

    2007-12-01

    Full Text Available Considerados do ponto de vista da teoria literária, os textos filosóficos que tratam explicitamente da política caem sobretudo sob os gêneros do tratado e do ensaio, mas, indiretamente, a teoria política sofre a influência das utopias, literárias ou experimentadas de fato. A validade de um tratado – e certamente também da enviesada crítica da economia política – depende do método que o sustenta, ao passo que no ensaio pesam as credenciais daquele que emite uma opinião. Por fim, cabe questionar o que significa o requisito da verdade nos textos utópicos, que variam da nostalgia ao sonho: o passado seria objeto da cronologia, que averiguaria a ocorrência de ilhas e paraísos, mas é muito difícil avaliar enunciados contrafatuais e sobre eventos futuros. A literatura sabe lidar com a ficção, enquanto a filosofia quer salvar pelo menos a crítica da pólis em seu momento presente.

  4. Memória e verdade em curso na Colômbia: o lugar destinado às vítimas

    OpenAIRE

    Motta (PPGCEPPAC/UnB), Maria Carolina Carvalho; Silva (UnB), Meire Cristina Cabral de Araújo

    2014-01-01

    O presente artigo tem por objetivo analisar o direito à verdade e à memória enquanto parâmetro da Justiça de Transição a ser implementada nas sociedades marcadas por conflitos violentos. Foi neste sentido que o contexto colombiano foi escolhido para esta análise, visto que este país, atualmente, presencia um debate sobre a validade das políticas públicas destinadas a pacificar os conflitos armados internos. A Ley de Justicia y Paz é o foco principal da análise e com seus termos legais se deba...

  5. «Los gritos de la verdad»: una imagen del Arte nuevo (vv. 43-44 y su significado

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    Adrián J. Sáez

    2012-12-01

    Full Text Available Una de las escasas facetas del Arte nuevo que la crítica no ha atendido como se merece se encuentra en los vv. 43-44, en la imagen de «los gritos que da la verdad en libros mudos». Este trabajo defiende que, pese a su aparente marginalidad, posee una notable importancia en el contexto de la poética y el pulso mantenido con las normas clásicas. Así, está construida sobre una amalgama de significados (iconográficos, simbólicos … y es una estrategia cargada de ironía destinada al doble receptor del texto.

  6. ¿Existe la verdad científica? Controversia histórica en torno al descubrimiento de Carlos J. Finlay

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    Rosa Luisa Aguirre del Busto

    Full Text Available Las autoras realizan el diseño de una simulación educativa en la asignatura Filosofía y Salud II, que forma parte del plan de estudios, del primer año, de las carreras de medicina, estomatología y enfermería, basada en el descubrimiento de Carlos J Finlay, sobre el agente transmisor de la fiebre Amarilla. Como resultado de una experiencia de trabajo a través de la Cátedra de Estudios CTS + I de la Universidad de la Habana, que propició el desarrollo del “Curso Experimental para la formación de docentes en el enfoque CTS”, realizado en el Campus Virtual de la OEI, se intenta reconstruir la polémica sobre el descubrimiento de Carlos J Finlay, y al mismo tiempo proporcionar herramientas teóricas en torno a la comprensión de la verdad científica como fenómeno social. Utilizando la metodología aprendida en el curso mencionado, se desarrolla el diseño de un “ Estudio de Caso Histórico”, que exige de una fundamentación, una guía didáctica, la contextualización de la controversia, definición de objetivos, identificación de actores y una serie de orientaciones a los alumnos que les permiten desplegar habilidades investigativas y conceptuales, pero que al mismo tiempo despiertan el interés por la vida y la obra del científico camagüeyano. En términos generales se concluye, señalando que es posible utilizar la historia de la medicina como una herramienta imprescindible de la enseñanza curricular del médico. La temática escogida desde la filosofía, sobre la verdad científica, les permite comprender el conocimiento como construcción social, impregnado de intereses y valores, pero de ningún modo arbitrario

  7. Tolerancia, verdad y libertad de conciencia en el siglo XVIII

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    Bello, Eduardo

    2004-06-01

    Full Text Available The 18th century defense of tolerance rests upon two lines of argument; lines that we can observe in thinkers such as Montesquieu and Rousseau, Diderot, Romilly and Voltaire. The first deconstructs the concept of absolute truth as it applies not only to the (orthodox doctrine itself, as revealed by God, but also to the Catholic Church insofar as it is taken to be the only institution where truth resides uniquely. The second line of argument would run as follows: Once we acknowledge the rights of consciousness to every single religion, how can we possibly avoid a circular justification of intolerance? Romilly and Voltaire defend, without renouncing to the rights of consciousness (which are the base of individual liberties, the Lockean thesis of the separation Church-State. However, they assign to the State the ius circa sacra. It is only upon this foundation that the idea and the practice of tolerance, both religiously as well as universally and multiculturally speaking, can be constructed.

    La defensa de la tolerancia, en el siglo XVIII, se apoya en dos líneas de argumentación, que observamos en pensadores como Montesquieu y Rousseau, Diderot, Romilly y Voltaire. Una es la que deconstruye el concepto de verdad absoluta aplicado tanto a la doctrina (ortodoxa, por ello revelada por Dios como a la institución considerada única depositaria de tal verdad, la Iglesia católica, única «verdadera». Otra sigue este argumento: si se reconocen los derechos de la conciencia a toda confesión religiosa, ¿acaso podría evitarse una justificación circular de la intolerancia? Sin renunciar a los derechos de la conciencia, base de las libertades individuales, Romilly y Voltaire sostienen la separación Iglesia-Estado, como lo hiciera Locke, asignando a éste el ius circa sacra. Sólo sobre esta base se logra fundamentar la idea y la práctica de la tolerancia no sólo religiosa, sino también universal o multicultural.

  8. Notas sobre o escândalo e o cinismo de Manet

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    Tereza Calomeni

    2013-10-01

    Full Text Available Em 1971, Foucault profere, em Túnis, uma conferência sobre a pintura de Manet. Em 1984, em A coragem da verdade, último curso oferecido no Collège de France, analisando o cinismo como expressão da parresia, novamente se refere ao pintor ao relacionar arte moderna e cinismo. A partir dos dois textos, o artigo reflete sobre o escândalo de Olympia, uma das treze telas examinadas na conferência, e a relação, estabelecida no curso, entre arte moderna e cinismo.

  9. “Cara ou coroa”: uma provocação sobre educação para índios

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    Maria Helena Paes Rodrigues

    2003-01-01

    Full Text Available O artigo apresenta-se como espaço de reflexão e algumas provocações sobre o “fazer” em educação indígena, tendo como foco de discussão a atual configuração de mundo globalizado que, com o crescente uso da tecnologia, fragiliza fronteiras entre as mais diferentes comunidades. Neste sentido, apresenta uma breve discussão sobre a compreensão de cultura, sob a perspectiva do campo dos Estudos Culturais, destacando a constituição de culturas e identidades híbridas. Localizando a escola enquanto espaço e instituição legitimada de construção e transmissão de verdades e valores simbólicos, discute a função e importância desta para as comunidades indígenas. Assim, levantam-se alguns questionamentos sobre as “verdades” e “valores” dos modelos de escola necessária propostos pelos não-índios para as comunidades indígenas.

  10. Novas Fontes, Novas Versões: Contribuições do Acervo da Comissão Nacional da Verdade

    Directory of Open Access Journals (Sweden)

    Alessandra Sá Mello Costa

    2017-03-01

    Full Text Available Na área de estudos organizacionais, o interesse dos pesquisadores em utilizar fontes e acervos históricos em suas pesquisas cresce a cada dia (Rowlinson, Hassard, & Decker, 2014; Yates, 2014. Como forma de enriquecer e aprofundar a discussão sobre esse movimento, a presente pesquisa tem por objetivo refletir sobre possíveis contribuições das fontes reunidas, sistematizadas e produzidas pela Comissão Nacional da Verdade (CNV. Instituída para investigar as graves violações dos direitos humanos cometidas no regime da ditadura civil-militar brasileira, a CNV (a partir de seu acervo oferece aos pesquisadores das organizações novas versões dos fatos históricos, o que torna possível não só problematizar e rever versões históricas oficiais hegemônicas, mas também investigar fenômenos organizacionais sob outras perspectivas. Assim, após a descrição do processo de constituição e de composição do seu acervo documental, foram elencadas quatro avenidas de pesquisas iniciais: (a sobre o apoio e a participação da sociedade civil na constituição e manutenção do governo civil-militar brasileiro; (b sobre a formação de redes de agentes sociais envolvidos no processo de criação e de trabalho da CNV; (c sobre as relações de trabalho durante o período, como a atuação dos sindicatos ou as práticas de recursos humanos sob um regime autoritário; e (d sobre o tema da história e memória das empresas.

  11. La elaboración de una Memoria Nacional: la Comisión de Verdad y Reconciliación de Sudáfrica

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    Fiona Ross

    2006-12-01

    Full Text Available La Comisión de Verdad y Reconciliación de Sudáfrica (Truth and Reconciliation Commission -TRC- creó un registro de la violencia cometida entre 1960-1994 durante el Apartheid. Siguiendo los ejemplos latinoamericanos, pretendía ofrecer una memoria colectiva sobre el pasado. La explicación resultante prioriza las experiencias individuales del daño inflingido (aberrantes violaciones a los derechos humanos. Si bien la elucidación sobre los perjuicios particulares es importante, ellos no están situados de manera adecuada dentro de los efectos sistemáticos y estructurales dañinos del Apartheid. Los patrones específicos sobre edad y género en los testimonios a la Comisión dan cuenta de una explicación del pasado que subvalúa los efectos del Apartheid sobre las mujeres, sobre todo las más jóvenes, al tiempo que subestima el rol que ellas jugaron en la resistencia al mismo. El énfasis de la Comisión sobre la violencia obstaculiza una comprensión de los procesos sociales usuales sobre los cuales las personas construyen su vida cotidiana. La "memoria colectiva" es insuficiente en la tarea de asegurar la democracia.A Comissão de Verdade e Reconciliação do Sul da África (Truth and Reconciliation Commission -TRC- criou um registro da violência cometida entre 1960-1994 durante o Apartheid. Seguindo os exemplos latino-americanos pretendia oferecer uma memória coletiva sobre o passado. A explicação resultante prioriza as experiências individuais de dano infringido (aberrantes violações aos direitos humanos. Ainda que a elucidação sobre os prejuízos particulares seja importante, eles não estão situados de maneira adequada dentro dos efeitos sistemáticos e estruturais nocivos da Apartheid. Os padrões específicos sobre idade e gênero nos testemunhos à comissão dão conta de uma explicação do passado que subestima os efeitos da Apartheid sobre as mulheres, sobretudo as mais jovens, ao mesmo tempo em que subestima o rol que

  12. A construção interpessoal do sentido moral de verdade: considerações sobre a filosofia do jovem Nietzsche = The construction of the interpersonal moral sense of truth: remarks on the philosophy of the young Nietzsche

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    Garcia, André Luis Muniz

    2013-01-01

    Full Text Available O presente artigo busca apresentar a perspectiva do jovem Nietzsche em Verdade e mentira em sentido extramoral, segundo a qual o sentido moral de verdade é construído a partir de convencionalização e regulamentação das práticas e dos usos (outrora arbitrários dos signos linguísticos. Para cumprir essa tarefa, pretende-se dividir o texto em três argumentos principais: (i Nietzsche e o estatuto da linguagem natural para o pensamento filosófico: metáfora como fator subjetivo da significação, (ii uso e significação: a construção interpessoal do sentido moral de verdade e (iii o que é moral no registro do simples pensar?

  13. La unidad de la verdad y la pluralidad de las culturas en Simone Weil

    OpenAIRE

    Amela Rueda, Rafael

    2016-01-01

    A mi modo de ver, la tesis de Weil de la existencia de una verdad universal en una pluralidad de culturas resulta ser una aportación al problema del diálogo intercultural e interreligioso, que merece ser considerada en tanto supone una postura que difícilmente encuentra parangón. Una convivencia auténtica de los seres humanos y sus sociedades pasa irremisiblemente, a ojos de esta pensadora, por el esfuerzo siempre renovado de hacer lo imposible por realizar la verdad en la vida individual y c...

  14. Um Olhar Pragmático Sobre Teorias do Direito: A Verdade Estética Como Reação à Incerteza

    OpenAIRE

    FALCÃO, Clóvis Marinho de Barros

    2013-01-01

    A teoria do direito atual apresenta fortes tendências céticas e relativistas, relacionadas à queda da modernidade e do ideal de ciência cartesiano. Essa é uma linha coerente, mas não a única possível. O olhar pragmatista, menos exigente em relação aos métodos racionais, não pressupõe uma tão séria crise da razão. A verdade estética do pragmatismo clássico reconhece a importância de elementos sutis da argumentação, permitindo uma melhor convivência com o ambiente de incerteza da...

  15. JUSTICIA TRANSICIONAL: DERECHO A LA VERDAD COMO CONSTRUCCIÓN DE FUTUROS

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    Aura María Echeverría

    2016-08-01

    Full Text Available El presente artículo hace parte del proyecto de investigación que tiene como objeto determinar la eficacia de las leyes que establecen la justicia transicional en Colombia, particularmente en algunos casos ocurridos en el departamento de Bolívar entre los años 1999 y 2001. Y dentro de los objetivos específicos del trabajo se propone conocer cada uno de los derechos correlacionales a la justicia transicional: verdad, justicia y reparación. En particular, el presente artículo es un avance del citado proyecto de investigación gira en torno a plantear que el conocer la verdad, vista ésta como construcción de la memoria histórica, puede facilitar los procesos de conciencia, colectividad, la sensibilización y el apoyo, hacia las víctimas y así la posibilidad de la reconciliación y de la construcción de paz en Colombia. El texto propone la siguiente estructura: i definir lo que en el presente trabajo se debe entender como verdad, ya que es un concepto con varias acepciones y significados, ii establecer como se relaciona la divulgación de esa memoria histórica con la construcción de futuro y transformación del conflicto en un contexto de complejidad creciente; iii Posteriormente, plantear como se puede convertir esta en la base de un proceso de transformación del conflicto.

  16. Salvaguardando los derechos fundamentales de acceso a la justicia y a la verdad. A propósito del caso: “Discoteca Utopía”

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    Jorge Isaac Torres Manrique

    2014-06-01

    Full Text Available Ante el arribo del Neoconstitucionalismo y Derecho Global, venimos siendo testigos del saludable desarrollo del derecho no solo del Estado peruano, principalmente por los aportes de la justicia constitucional.Ello redunda y fortalece positivamente el Sistema Jurígeno, Estado Constitucional de Derecho y sobre todo el Sistema de Administración de Justicia.Así, instituciones como el derecho a la verdad y acceso a la justicia, cobran mayores alcan-ces y reconocimientos.En la presente entrega, el autor analiza y comenta ampliamente una resolución de la Corte Suprema que resuelve un caso emblemático, la misma que considera, las reivindica valientemente.

  17. O SENTIDO DA HESITAÇÃO NO CONTEXTO DA PÓS-VERDADE

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    Lúcia Schneider Hardt

    2018-01-01

    Full Text Available Sempre estivemos excessivamente preocupados com a verdade. De início, verdades religiosas, depois científicas e hoje aquelas que necessariamente devem conferir com nossas convicções. Assim, a verdade aproxima-se também da mentira. Para todos os tempos, parece, precisamos reaprender o sentido da hesitação. Um sentido que evita a pressa, oferece ao tempo outra forma de fazer acontecer a vida, oferece aberturas, rachaduras, rasgos que merecem mais atenção para serem compreendidos. Hesitar, suspender, aguardar. Ruminar é necessário, precisamos reaprender a nos apresentar indagando, perguntando. O diálogo é a forma artística mais clássica da filosofia. Nietzsche retoma o diálogo como ferramenta filosófica não para fazer triunfar uma ideia, mas mostrar uma disposição para pensar, insinuar respostas. Reconhecer as sinuosidades de qualquer orientação. Enfim, a hesitação como expressão de uma outra formação humana.   PALAVRAS-CHAVE: Hesitação; Formação; Diálogo.     ABSTRACT We have always been overly concerned with the  concept  of truth. Initially religious truths, then scientific and currently those that must necessarily confer with our convictions. The the  concept of truth is thus close to the concept  of lie. In any historical time we need to relearn the sense of hesitation. A sense that avoids any haste, offers  another way of making life happen, offering openings, cracks, tears that deserve more attention in order to be understood. To hesitate, to suspend, to wait. Ruminating is necessary, since we need to relearn a way to present ourselves by asking, questioning. Dialogue is the most classic artistic form of philosophy. Nietzsche retakes the dialogue as a philosophical tool not to make an idea triumph, but to show a willingness to think, to insinuate answers. To recognize the windings of any orientation. Finally, hesitation is an expression of  a different human formation.   KEYWORDS: Hesitation

  18. Skinner e Feyerabend sobre o Método e o Papel da Ciência em uma Sociedade Livre

    OpenAIRE

    Rocha, César Antonio Alves da

    2017-01-01

    Resumo Da obra de B. F. Skinner fazem parte preocupações de ordem epistemológica, encerrando discussões sobre metodologia e critérios de verdade, e outras de ordem política e social, concernentes à relação entre ciência e sociedade. De um discurso, em alguns aspectos, coincidentes com uma forma de positivismo, Skinner passou a crítico de tendências puramente formalistas sobre o método científico, e de uma defesa do gerenciamento da sociedade por especialistas, passou a uma crítica à centraliz...

  19. O impulso formativo do pensamento crítico: racionalidade, verdade e constelação.

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    Mauricio João Farinon

    2015-01-01

    Full Text Available http://dx.doi.org/10.5902/1984644414823O ensaio analisa a concepção de pensamento e subjetividade em Theodor Adorno, indicando os desafios educacionais que surgem dessa concepção. Defende uma concepção de verdade definida na dinamicidade histórica. A contraposição entre conhecimento e procedimento, as noções de evidência, constelação e conteúdo de verdade, são decisivas para caracterizar o pensamento pós-metafísico e indicar os desafios na formação do sujeito segundo Adorno. Quando o conhecimento perde seu lugar pelo ideal de procedimento eficaz, ocorre o retardo da consciência, e a força do sujeito é abalada. A possível condição para reverter tal caracterização é admitir a ausência de evidência como impulso ao esclarecimento. Neste ponto é que se situa a noção de constelação e conteúdo de verdade e o impulso formativo do pensamento crítico.

  20. MITOS Y LEYENDAS SOBRE LOS JUEGOS DE ROL

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    Rocío Tizón

    2010-11-01

    Full Text Available Los juegos de rol aparecen en la década de los años 70 en Estados Unidos, creados por Gary Gigax y Dave Arneson, padres del ya famoso Dragones & Mazmorras. No obstante, fueron pocos los años de tranquilidad, ya que en su país natal se le consideró culpable de promover el suicidio de varios adolescentes que habían sido jugadores de Dragones & Mazmorras. Los engaños de la información y los prejuicios de las noticias sobre estos juegos de rol provocaron que varias personas se interesaran por este fenómeno, analizando dichos mitos y comprobando la verdad de estos rumores. Uno de estos estudiosos fue William Watson, creador de la página web The Inquirer, en la que se dedica a desmontar estos y otros tópicos sobre juegos de rol.

  1. Un país de verdad

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    Luz Rodríguez Carranza

    2011-06-01

    Full Text Available En diciembre del 2001 dejaron de circular en Argentina tanto la moneda convertible al dólar como la seguridad jurídica de la deuda. Se esfumó toda confianza en la representación económica y política, y no hizo falta explicarle a nadie que las palabras no tenían nada que ver con las cosas: la gente salió a la calle exigiendo autenticidad y verdad, valores que ya no tenían parámetros comunes ni circulaban en la esfera pública, y que resultaban de pronto tanto imposibles como indispensables. El trueque reemplazó al mercado, y las asambleas directas y “cacerolazos” hicieron caer presidente tras presidente hasta mayo de 2003.

  2. EL CUERPO DEL ARCHIVO: FUNCIÓN, TESTIMONIO Y LA RESPONSABILIDAD DE UN ORDEN. APUNTES SOBRE 'INSENSATEZ' Y 'DOS VECES JUNIO'

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    Martín Lombardo

    2018-01-01

    Full Text Available A partir de las novelas Insensatez de Horacio Castellanos Moya y Dos veces junio de Martín Kohan, el presente artículo reflexiona sobre la representación de un archivo y de un testimonio en un texto narrativo. A través de dos maneras diferentes en que se hace uso del archivo y del documento institucional para hacer una denuncia política, las dos novelas interrogan sobre el estilo de redacción de un documento, sobre los usos del cuerpo de quien cumple una función institucional, sobre la tensión entre el archivo y el testimonio para así plantear el vínculo entre lo irrepresentable del horror, la fantasía y la verdad histórica.

  3. Experimental study on fuel oil combustion in circulating fluidized bed; Estudio experimental sobre la combustion de combustoleo en lecho fluidizado circulante

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Rangel, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The Instituto de Investigaciones Electricas (IIE) developed a circulating fluidized bed combustor of 0.5 thermal MW unique in its type in Latin America. The Bachelor`s thesis entitled ``Experimental Study on Fuel Oil Combustion in Circulating Fluidized Bed`` was performed operating this combustor with the purpose of determining the feasibility of burning heavy fuel oil in a stable and sustained form, as well as the effect of the addition of calcium carbonate to the combustor. The results of the experimental trials showed heavy fuel oil can be burned in a circulating fluidized bed, with low sulfur dioxide emissions. During the conduction of the experiments a sulfur retention of 43% was achieved with a Ca/S relationship of 4.5. [Espanol] El Instituto de Investigaciones Electricas (IIE) desarrollo un combustor de lecho fluidizado circulante de 0.5 MW termicos de potencia, unico en su tipo en Latinoamerica. La tesis de licenciatura titulada Estudio Experimental sobre la Combustion de Combustoleo en Lecho Fluidizado Circulante se realizo operando dicho combustor, con el proposito de determinar la factibilidad de quemar combustoleo pesado en forma estable y autosostenida, asi como la influencia que tiene la adicion de carbonato de calcio al lecho. Los resultados de los ensayos experimentales mostraron que se puede quemar combustoleo pesado en un lecho fluidizado circulante, con bajas emisiones de bioxido de azufre. Durante la experimentacion se logro una retencion de azufre del 43%, con una relacion Ca/S de 4.5.

  4. Experimental study on fuel oil combustion in circulating fluidized bed; Estudio experimental sobre la combustion de combustoleo en lecho fluidizado circulante

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Rangel, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The Instituto de Investigaciones Electricas (IIE) developed a circulating fluidized bed combustor of 0.5 thermal MW unique in its type in Latin America. The Bachelor`s thesis entitled ``Experimental Study on Fuel Oil Combustion in Circulating Fluidized Bed`` was performed operating this combustor with the purpose of determining the feasibility of burning heavy fuel oil in a stable and sustained form, as well as the effect of the addition of calcium carbonate to the combustor. The results of the experimental trials showed heavy fuel oil can be burned in a circulating fluidized bed, with low sulfur dioxide emissions. During the conduction of the experiments a sulfur retention of 43% was achieved with a Ca/S relationship of 4.5. [Espanol] El Instituto de Investigaciones Electricas (IIE) desarrollo un combustor de lecho fluidizado circulante de 0.5 MW termicos de potencia, unico en su tipo en Latinoamerica. La tesis de licenciatura titulada Estudio Experimental sobre la Combustion de Combustoleo en Lecho Fluidizado Circulante se realizo operando dicho combustor, con el proposito de determinar la factibilidad de quemar combustoleo pesado en forma estable y autosostenida, asi como la influencia que tiene la adicion de carbonato de calcio al lecho. Los resultados de los ensayos experimentales mostraron que se puede quemar combustoleo pesado en un lecho fluidizado circulante, con bajas emisiones de bioxido de azufre. Durante la experimentacion se logro una retencion de azufre del 43%, con una relacion Ca/S de 4.5.

  5. Discursos de enfermeiras sobre morte e morrer: vontade ou verdade? Discursos de enfermeras sobre la muerte y el morir: ¿Voluntad o verdad? Nurses' speeches on death and to die: truth or will?

    Directory of Open Access Journals (Sweden)

    Karen Schein da Silva

    2009-06-01

    Full Text Available Propomos olhar para a morte e o morrer como uma construção social, histórica e cultural. Assim, nos aproximamos dos Estudos Culturais para conhecer discursos de enfermeiras sobre o tema. O corpus da pesquisa são artigos de dois periódicos nacionais de enfermagem. Nas análises utilizamos ferramentas propostas por Michel Foucault que possibilitaram constituir quatro categorias: a morte silenciada e ocultada; travando uma luta contra a morte; a morte em cena: multiplicidade de facetas e a morte e os cuidados paliativos: mudança de paradigma. O estudo destaca o modo como as publicações operam na produção dos saberes sobre a morte e o morrer subjetivando as enfermeiras.Nos proponemos mirar la muerte y el morir como una construcción social, histórica y cultural. Así, nos aproximamos a los Estudios Culturales para conocer discursos de enfermeras sobre el tema. El corpus de la investigación son artículos de dos periódicos nacionales de enfermería. En nuestros análisis utilizamos herramientas propuestas por Michel Foucault que posibilitaran construir cuatro categorías: la muerte silenciada y ocultada; entablando una lucha contra la muerte; la muerte en escena: multiplicidad de facetas, y la muerte y los cuidados paliativos: cambio de paradigma. El estudio destaca el modo en que las publicaciones operan en la producción de los saberes sobre la muerte y el morir subjetivando a las enfermeras.We consider looking at the death and dying as a social, historical and cultural construction. Thus, in we approach them to the Cultural Studies to know nurses´ speeches on the subject. The research is periodic articles of two national ones of nursing. In the analyses we use tools proposals for Michel Foucault that they make possible to constitute four categories: the silenced and occulted death; stopping one it fights against the death; the death in scene: multiplicity of faces and the palliative death and cares: paradigm change. The study

  6. Jogos de linguagem/jogos de verdade: de Wittgenstein a Foucault

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    Elza Ibrahim

    2014-01-01

    Full Text Available El artículo trae a discusión la cuestión de la constitución del sujeto a través de los juegos de verdad y de los juegos de lenguaje, problematizados, respectivamente, por Michel Foucault y Ludwig Wittgenstein, teniendo como hilo conductor las implica - ciones del lenguaje en las prácticas que realizadas en un hospital psiquiátrico-penal con pacientes inimputables. Para ello, presentamos la visión objetivista de realidad y del lenguaje figurativo, en lugar del punto de vista constructivista de la realidad y del lenguaje pragmático. De acuerdo con este último punto de vista, la realidad es producida por el lenguaje a través de juegos de lenguaje, históricamente contextua - lizadas. Por lo tanto, estaríamos hablando de sujetos únicos, y no del sujeto trascen - dental. En este contexto, traemos a la discusión la noción de verdad problematizada por Foucault como un campo de potencial. Para él, es tan sólo en la contingencia de la historia que se constituye el sujeto: como el lenguaje, él es producto de múltiples prácticas sociales.

  7. Esperando una Respuesta:El desordenado proceso de buscar la verdad.

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    Susan Haack

    2009-05-01

    Full Text Available Hace algunos años oí a mi Decano, formado en física, expresar su malestar con la sugerencia de que la declaración de la misión del College of Arts and Sciences incluyera la frase “interés por la verdad”. La palabra pone nerviosa a la gente, advirtió, y los obligaa preguntar “¿la ‘verdad’ de quién?”. Un colega sociólogo, respaldando las aprensiones del Decano, señaló que aunque, por supuesto, sus investigaciones hacen avanzar el conocimiento, él no está interesado en la “verdad”. Algunos de nosotros señalamos que, a menos que las conclusiones sean verdaderas, no son realmente conocimiento, sólo pretendido conocimiento; e hice lo mejor que pude para explicar que del hecho que la gente disienta acerca de lo que es la verdad no se infiere que la verdad sea relativa a las perspectivas. Pero en su momento el Plan Estratégico del College especificaba innovaciones curriculares requeridas por las “preguntas fundamentales” que han surgido “acerca de las presuntas universalidad y objetividad de la ‘verdad’ “.

  8. Development of flameless combustion; Desarrollo de la combustion sin flama

    Energy Technology Data Exchange (ETDEWEB)

    Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

    2010-11-15

    The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

  9. Un país de verdad

    Directory of Open Access Journals (Sweden)

    Luz Rodríguez Carranza

    2011-01-01

    Full Text Available http://dx.doi.org/10.5007/1984-784X.2011v11n16p111 En diciembre del 2001 dejaron de circular en Argentina tanto la moneda convertible al dólar como la seguridad jurídica de la deuda. Se esfumó toda confianza en la representación económica y política, y no hizo falta explicarle a nadie que las palabras no tenían nada que ver con las cosas: la gente salió a la calle exigiendo autenticidad y verdad, valores que ya no tenían parámetros comunes ni circulaban en la esfera pública, y que resultaban de pronto tanto imposibles como indispensables. El trueque reemplazó al mercado, y las asambleas directas y “cacerolazos” hicieron caer presidente tras presidente hasta mayo de 2003.

  10. El peso del contenido publicitario en la prensa alicantina: el caso del Diario Información y La Verdad The role of advertising content in newspapers in Alicante : the case of Diario Información and La Verdad.

    Directory of Open Access Journals (Sweden)

    Alicia de Lara González

    2011-04-01

    Full Text Available At the moment, the press is facing a double crisis. Both, the general crack and the fall in advertising, which affects it most directly. The lack of adverts is causing in this mass media a situation contrary to what might be expected: the total percentage of space occupied by commercial content remains constant and even rising. This behaviour is surprising when you consider that the economic downturn forced advertisers to reduce their spending on advertising investment. However, as shown in this study, the main newspapers in Alicante: Diario Información and La Verdad, use several strategies, some more profitable than ethical, to counteract the loss of advertising. This is reflected in the scale that balances the editorial content and advertising spots. The study was based on 1.094 newspapers, divided equally between the two media and for the years 2007, 2008 y 2009.La doble crisis que atraviesan los periódicos, la propia del mercado en general y la publicitaria que les afecta más directamente, provoca en el medio impreso una situación contraria a la que cabría esperar: el porcentaje de espacio ocupado por el contenido comercial se mantiene constante. Un comportamiento que sorprende si tenemos en cuenta que la recesión económica obliga a los anunciantes a reducir su gasto en inversión publicitaria. La presente investigación refleja cómo las dos principales cabeceras en la provincia de Alicante, el Diario Información y el periódico La Verdad, recurren a estrategias poco lícitas para contrarrestar la pérdida de inserciones publicitarias, un dato que queda reflejado en la balanza que equilibra el contenido editorial y la mancha publicitaria. El estudio se realiza sobre una muestra comprendida por 1.094 ejemplares, distribuidos de forma equitativa entre ambas cabeceras y entre los años 2007, 2008 y 2009.

  11. ¿Buen sexo o sexo de verdad? Perspectivas sobre la regulación del género Good sex or true sex? Perspectives on gender governance

    OpenAIRE

    Soley-Beltrán, Patricia

    2013-01-01

    La medicalización de conductas no acordes con nociones binarias y estereotipadas de la identidad de género y la sexualidad produce una serie de categorías patologizantes, como la "disforia de género", la "transexualidad" o el "transvestismo", que operan como proveedo-ras de cuidado mediante la producción de la ´verdad´ del género y el "sexo". Tras examinar el proceso de institucionalización y medicalización de la identidad de género de la última década en España, en este artículo consideraré ...

  12. O DIREITO À MEMÓRIA E À VERDADE NO BRASIL PÓS-DITADURA CIVIL-MILITAR

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    Carlos Artur Gallo

    2010-12-01

    Full Text Available O presente estudo analisa em que consiste, como surge e quais as possibilidades de concretização do “direito à memória e à verdade” na realidade brasileira. Concebido como mecanismo de reconciliação das sociedades que tenham passado por experiências traumáticas (assim chamadas em virtude da reiterada violação aos direitos humanos que foi consumada nas mesmas, este direito consiste, basicamente, no resgate da memória e da verdade dos fatos referentes às trajetórias daqueles que foram perseguidos e/ou mortos pelo regime autoritário vigente. No caso brasileiro, verifica-se que a memória e a verdade enquanto direitos tem sido pouco a pouco melhor tratadas, contudo, segue-se enfrentando sérios obstáculos à sua efetivação.

  13. O valor verdade no ensino da enfermagem: um estudo fenomenológico El valor verdad en la educación de enfermería: un estudio fenomenológico The truth value in nursing education: a phenomenological study

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    Gilberto de Lima Guimarães

    2013-03-01

    Full Text Available O presente artigo é balizado na teoria de valor. A enfermagem possui um conjunto de valores do qual se nutre para elaborar uma escala que direciona e justifica o agir profissional. Objetivo: compreender no ato de educar do enfermeiro-docente o valor verdade e discuti-los a luz dos pressupostos de Max Scheler. A metodologia é qualitativa, centrada no enfoque fenomenológico. Participaram do estudo sete enfermeiros-docentes de três instituições de ensino superior de enfermagem, localizadas na cidade do Rio de Janeiro. O período de realização foi de maio a junho de 2008. Os dados foram obtidos através de entrevista e analisados compreensivamente. Resultado: o valor verdade emergiu no discurso do enfermeiro-docente no ato de educar. Considerações finais: foi por meio do ato de educar que o enfermeiro apresentou o valor verdade ao educando, ratificando-o como instituinte para a práxis assistencial da enfermagem.Este artículo está enmarcado en la teoría del valor. La enfermería tiene un conjunto de valores de los que se nutre para desarrollar una escala que dirige y justifica el acto profesional. Objetivo: Comprender en el acto de educar de enfermeros-docentes el valor verdad y discutirlo a la luz de las presuposiciones de Max Scheler. La metodología es cualitativa, centrada en el abordaje fenomenológico. Los participantes del estudio fueron siete enfermeros-docentes de tres instituciones de educación superior de enfermería, ubicadas en la ciudad de Río de Janeiro. El período de ejecución fue de mayo a junio de 2008. Los datos fueron recolectados a través de entrevistas y analizados exhaustivamente. Resultado: El valor verdad emergió en el discurso del enfermero-docente en el acto de educar. Consideraciones finales: Fue a través del acto de educar que el enfermero presentó el valor verdad al estudiante, confirmándolo como parte integrante de la praxis asistencial de enfermería.This article is based on the value theory

  14. Verdad sublime y madre asesina en Christine V., versión de Marguerite Duras

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    Juliana González Holguín

    2016-01-01

    Full Text Available Todo relato es ficción, versión y, así mismo, verdad, bajo una u otra concepción de la misma, es decir, desde una perspectiva que se enfoca según la intención y la subjetividad de uno o más actores, de uno o más narradores. El texto de Marguerite Duras intitulado Sublime forcément sublime Christine V. involucra, por su contenido y su contexto, varias versiones que contrastan y se interrogan entre sí. La escritora se posiciona de tal manera que, a través de recursos propios del oficio literario, desentraña una verdad que puede no ajustarse a la realidad o al saber, pero que nos enfrenta a los límites de lo pulsional y lo ominoso.

  15. “Uma floresta tocada apenas por homens puros...” ou do que aprendemos com os discursos contemporâneos sobre a amazônia

    OpenAIRE

    Shaula Maíra Vicentini de Sampaio

    2012-01-01

    A presente tese reflete sobre uma rede discursiva a partir da qual são produzidas (e ensinadas) algumas verdades sobre a floresta amazônica, entre as quais está o entendimento de que as populações designadas tradicionais apresentam modos de habitar esse espaço e de se relacionar com a natureza dessa região considerados mais adequados e sustentáveis. Dessa forma, o argumento central que o estudo desenvolve é que a noção de sustentabilidade atua como um dispositivo estratégico na constituição e...

  16. Los silencios en la memoria. Narrativa de la violencia sexual en la Comisión de la Verdad y Reconciliación de Perú

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    Sandra Marcela Arvesú Juárez

    2016-01-01

    Full Text Available El conflicto armado interno que asoló Perú durante las dé - cadas de 1980 y 1990 tuvo diversas y devastadoras consecuencias para mucha de la población civil y de manera particular para las mujeres. De acuerdo con el Informe Final de la Comisión de la Verdad y Reconci - liación de Perú ― CVR ― , la violencia sexual fue el principal crimen cometido en contra de ellas, considerado por primera vez en un país latinoamericano como una violación a los derechos humanos y, dado su carácter generalizado, un crimen de lesa humanidad. De ahí el interés de reflexionar en este artículo sobre el tema de la violencia sexual durante el conflicto armado interno en Perú desde la perspectiva de los estudios de la memoria, con el objetivo de analizar la narrativa construida por la Comisión sobre la violencia sexual y al mismo tiempo problematizar cómo se recuerda, quiénes recuerdan, y qué alcance ha tenido su reco - nocimiento como parte de la memoria histórica del conflicto.

  17. A verdade como um exército de metáforas. Entre o dogmático e o estético em religião e literatura.

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    Flávio Augusto Senra Ribeiro

    2015-04-01

    Full Text Available Em 1873, Nietzsche dita a seu amigo Gusdorff o opúsculo Über Warhrheit und Lüge im auzsermoralischen Sinn. O texto versa sobre o tema que nesta comunicação se pretende abordar, a saber, sobre o limite do conhecimento sob a original afirmação da verdade como exército de metáforas. Esse novo limite delineia o horizonte para certa indagação sobre o perfil do conhecimento dogmático e o do conhecimento estético no confronto entre religião e literatura. Inicialmente, o texto irá apresentar a crítica de Nietzsche à abordagem metafísica, na qual se estrutura o fenômeno linguagem, particularmente entendido como gramática, ou seja, um tipo de metafísica popular. Em seguida, a comunicação procurará descrever a proposta de superação do conceito em sua formulação metafísica por uma compreensão estética. Por fim, caberá uma provocação, em chave de leitura “pós-moderna” sobre a possível ressignificação do saber estético em religião e literatura. A questão que aqui se apresenta está posta ao modo de uma aproximação, talvez um ensaio que exigirá, seguramente, aprofundamentos futuros.

  18. A coisificação do “eu” e a personificação da “coisa” nas redes sociais: verdades e mentiras na formação das estruturas de identidades

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    Jefferson Cabral Azevedo

    2012-04-01

    Full Text Available O presente artigo tem como finalidade discorrer sobre os aspectos formadores das identidades e suas relações no mundo não-virtual, o que caracteriza a formação de falsas personalidades, ou identidades, para permitir aceitação nas Redes Sociais. Esse fenômeno afeta um grande número de pessoas devido a sua rápida propagação, causando incerteza sobre o que é mentira ou verdade nas relações virtuais. Nesse espaço virtual ocorre uma coisificação do EU e uma personificação da COISA. Aos traços das falsas identidades também se dão no nível psicológico, podendo, inclusive, ser analisados sob o ponto de vista psicanalítico, sociológico, filosófico e, até certo ponto, criminal, evidenciando as estruturas de personalidades desviantes.

  19. Estimando a necessidade: os oráculos de ifá e a verdade em Havana

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    Martin Holbraad

    2003-10-01

    Full Text Available O objeto deste artigo é o conceito de verdade tal como se articula no oráculo de Ifá cubano; seu objetivo é ilustrar a fecundidade de um "método ontográfico" que procure mapear as premissas ontológicas do discurso nativo por meio da produção de conceitos que, não sendo os conceitos nativos eles mesmos, constituam equivalentes aproximados destes. Enfatizando a afirmação dos praticantes de que o Ifá é infalível, propõe-se que os vereditos divinatórios devem ser entendidos como verdades necessárias, isto é, como enunciados que não poderiam não ser verdadeiros. Em seguida, mostrando que, do ponto de vista das concepções comuns de verdade, a necessidade modal dos oráculos só pode parecer um absurdo dogmático, procura-se avançar uma conceitualização alternativa que concorde com as convicções dos informantes, examinando um complexo de conceitos e práticas associados ao oráculo a fim de avaliar as premissas que garantem a verdade e sua emergência na prática do Ifá.This article analyzes the concept of truth as employed by Ifá oracles in Cuba; its aim is to illustrate the fertility of an 'ontographic method' dedicated to mapping the ontological premises of native discourse through the production of concepts which, while not the native concepts themselves, comprise close equivalents to them. Emphasizing practitioners claims that the Ifá is infallible, it is proposed that divinatory verdicts should be understood as necessary truths, that is, as statements which cannot not be true. Then, after showing that from the viewpoint of common place conceptions of truth, the modal necessity of oracles can only appear a dogmatic absurdity, I propose an alternative conceptualization which agrees with the convictions of informants. This involves examining a complex of concepts and practices linked to the oracle in order to evaluate the premises which ensure truth and its emergence in Ifá practice.

  20. Foros: Verdades y Mitos sobre las Células Madre (CM.

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    Efraím Otero Ruiz

    2005-09-01

    La Dra. Martalucía Tamayo dijo que por su experiencia individual podría asumir ella los tres roles como investigadora, como paciente y como periodista. Como investigadora, sostiene que la experimentación debe basarse en el método científico y debe cumplir no sólo con la apropiación social del conocimiento sino también sus relaciones adecuadas con la sociedad (pacientes, familias y con los medios de comunicación masiva. En el caso de las CM, embrionarias o adultas debe advertirse que las terapias posibles son aún experimentales y con ese carácter deben tener impacto en su legislación; esas fases experimentales deben incluir microbiología, ensayos en animales pequeños y grandes para luego pasar a humanos y en esta última fase ser controladas por entes como lo hace la FDA en los Estados Unidos, pero persiste el interrogante de cómo controlar ectivamente los modelos humanos. Deben balancearse los beneficios en lo personal vs. lo social, evaluar los costos individuales y sobre los sistemas de salud. Como paciente prefiere que se definan bien los beneficiarios potenciales, explicarles las posibilidades reales del procedimiento incluyendo riesgos y costos, aceptando con esperanza y firmeza tanto su enfermedad como cualquier solución que se les prometa. Cree que deben establecerse asociaciones de pacientes que evalúen tanto las expectativas, reales o falsas como los costos sociales y económicos, ya que las falsas esperanzas pueden traducirse en más frustración para los mismos...

  1. Estudio del Efecto de la Altitud sobre el Comportamiento de Motores de Combustión Interna. Parte 1: Funcionamiento Study of the Altitude Effect on Internal Combustion Engine Operation. Part 1: Performance

    OpenAIRE

    Magín Lapuerta; Octavio Armas; John R Agudelo; Carlos A Sánchez

    2006-01-01

    En este trabajo se estudia el efecto de la altitud sobre la potencia en motores de aspiración natural y turbosobrealimentados sin sistemas correctores, en función de la presión ambiental. La altitud sobre el nivel del mar tiene un notable efecto sobre la densidad del aire y su composición. Dado que los motores de combustión interna tienen sistemas de admisión y de inyección de combustible volumétricos, la altitud modifica el ciclo termodinámico de operación, y en consecuencia las prestaciones...

  2. “La excavación” de Roa Bastos y “Emma Zunz” de Borges, en honor a la verdad

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    Cecilia Rubio Rubio

    2014-06-01

    Full Text Available En este artículo presento la relación intertextual entre el relato “La excavación” (El trueno entre las hojas, 1953 de Augusto Roa Bastos y el borgia- no “Emma Zunz” (El Aleph, 1949, a partir del análisis contrastivo. Ade- más, presento y comento la segunda versión de “La excavación” (Madera quemada, 1967 y la comparo con la primera, advirtiendo el alejamiento de la intertextualidad con Borges. Finalmente, someto a interpretación este cambio, comentando la distinción entre “verdad moral” y “verdad factual” que se presenta en los dos relatos.

  3. ESSÊNCIA E VERDADE: DUAS CATEGORIAS DO MÉTODO EM MARX

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    Ranieri Carli

    2011-05-01

    Full Text Available O presente artigo pretende estudar alguns dos aspectos do método de Marx,especialmente o tratamento dado a duas categorias: essência e verdade. Herdeiro datradição racionalista, Marx mantém em seu aparato categorial tanto a essência quanto averdade, ambas entrelaçadas uma à outra. Na mesma medida, será nosso intento atentarpara a peculiaridade do tratamento legado por Marx a essas duas categorias, tendo emconta as especificidades do materialismo de sua concepção teórica.

  4. Una manera de nombrar el deseo en Toda esa gran verdad

    OpenAIRE

    List Reyes, Mauricio

    2011-01-01

    Este artículo analiza la novela Toda esa gran verdad (2006) del mexicano Eduardo Montagner. El artículo centra su atención en el tema de la sexualidad, particularmente la del personaje principal. La idea es reflexionar acerca de formas disidentes de la sexualidad que rompen con las maneras normativas y que son sancionadas socialmente. En este caso en particular, unas botas de hule son el centro de la atención de un joven de una comunidad rural que dice estar enamorado del dueño de dicho calza...

  5. El espíritu de la verdad en Teresa de Jesús y Edith Stein. Testimonio y mística

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    Silvia Julia Campana

    2015-04-01

    Full Text Available Teresa de Jesús y Edith Stein son testigos del Amor desbordante, embriagadas en el perfume de la Verdad que las reúne en una búsqueda común. “Cuando venga el Espíritu de la Verdad, él los introducirá en toda la verdad”. Ambas son transformadas, desde la hondura del Espíritu que las habita, en testimonio de la libertad que brota de la Verdad que sale al encuentro; en testimonio de la autenticidad de una vida entregada al Otro/otros; en testimonio de un secreto que las habita, las transforma y las conduce hasta la ofrenda de la propia vida. Porque el testimonio, como afirma Ricoeur, “es también el compromiso de un corazón puro y un compromiso hasta la muerte. Pertenece al destino trágico de la verdad”. Teresa de Jesús ingresa a la vida de la joven filósofa Edith Stein a través de la palabra, del “poema” que relata su propia vida y le descubre un mundo nuevo. Biografía que transforma otra biografía y nos permite hoy reunirlas en la comunidad del testimonio y la mística.

  6. Sobre verdad y falsedad en el mito griego: Pistas desde la filosofía para concebir un modo de verdad presente en el mito On truth and falsity in greek myth: Philosophical suggestions to conceive a sort of truth present in myth

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    Raúl Madrid Meneses

    2011-10-01

    Full Text Available El discurso filosófico, a lo largo de su historia y específicamente para referirse a sus comienzos, se ha puesto en relación al discurso mítico en términos de ruptura, liberación o superación. Con ello, se han sentado las bases para atribuir el carácter de falsedad de este último. Dicho carácter ha sido mantenido y es utilizado de manera cotidiana en el plano coloquial y académico investigativo. Así, nuestro trabajo, en primer lugar, pondrá de manifiesto esta relación de oposición entre discurso mítico y discurso filosófico. En segundo lugar, se dará a la tarea de exponer de la mano de los planteamientos de Hans-Georg Gadamer, cómo fue que el discurso mítico adquirió el carácter de falsedad a lo largo de la historia, puesto que en los griegos no lo tendría. Y, finalmente, con Nietzsche consideramos que el modo de verdad de la ciencia, por el cual medimos el discurso mítico, está lejos de ser el único y el más asertivo. Con ello, pensamos, se abre la posibilidad de considerar cierto modo de verdad presente en el discurso mítico.The philosophical discourse, throughout its history, and specifically to refer to its beginnings, has become legendary in relation to the discourse in terms of rupture, release or improvement. This has provided the basis for attributing a false nature to the latter. This characteristic has been maintained and is used on a daily basis at the conversational and academic research. Thus, firstly our work will highlight this relationship of opposition between mythic and philosophical discourse. Secondly, it will show, following the approaches of Hans-Georg Gadamer, how mythical discourse acquired this false characteristic throughout history, as the Greeks would not have it. And lastly, with Nietzsche we believe that the true mode of science, by which we measure the mythical discourse, is far from being the only and most assertive one. This, we think, opens the possibility of considering some sort of

  7. Entre el saber y la verdad,el enigma del sujeto.

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    Luz Stella Alzate.

    2002-03-01

    Full Text Available El presente texto constituye un intento de dimensionar la posición del sujeto tanto para la filosofía como papa el psicoanálisis, como un ser estructuralmente escindido. Esto es, como un ser constituido a partir de una división estructural entre el saber y la verdad, en medio de los cuales se prefiguran el mito y el enigma como estructuras discursivas. Partiendo de esta división, se hace un breve análisis de la tragedia de Medea, de Eurípides, de la cual se obtienen algunos elementos para ilustrar la posición de algunas mujeres en lo que respecta al fenómeno de la violencia intrafamiliar.

  8. Ocho verdades a medias sobre la deuda interna....y una guía para una solución alternativa

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    Henry Manuel Mora Jiménez

    2011-09-01

    Full Text Available En el debate nacional sobre temas públicos de actualidad, destaca en los últimos meses la gran controversia que se ha generado en torno a los orígenes, causas, magnitud y consecuencias de la deuda pública interna. Y como este tema se vincula estrechamente con nuestras concepciones sobre el Estado y el papel de éste en la economía y en la sociedad, es sumamente difícil que nuestras opiniones al respecto se puedan liberar enteramente de prejuicios y estereotipos ideológicos, lo mismo que de determinados intereses materiales concretos. Todos tendemos a acercarnos a los problemas que analizamos con ciertas ideas preconcebidas, limitando nuestro entendimiento a lo que nos es familiar y habitual, condicionados por nuestro ambiente, por los intereses que nos afectan, por la experiencia previa sobre el tema, y por todo tipo de circunstancias en que nos desenvolvemos. Por este motivo, es de crucial importancia que los grandes problemas nacionales se filtren a través de un amplio y democrático debate público, que además debe ser adecuadamente conducido.

  9. Dialogismo e vontades de verdade na discursividade da Cinderela

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    Maria Angélica de Oliveira

    2016-01-01

    Full Text Available O dialogismo apresenta-se como fundamento de toda a discursividade; pois, considere-se que todo enunciado, enquanto materialidade discursiva abriga um universo de vozes sociais em múltiplas relações de convergência e de divergência, de harmonia e de conflito, de aceitação e de recusa. Partindo desse princípio, o texto, na sua qualidade de enunciado, é compreendido, no seio dos estudos literários, como uma voz que dialoga com outros textos, funcionando também como ecos das vozes de seu tempo, de sua história, revelando os valores, as crenças, as vontades de verdade de uma dada formação social. A partir dessa perspectiva, trazemos uma releitura de um tradicional conto popular de origem de língua românica europeia que ficou conhecido em todo o mundo como a história da Cinderela ou da GataBorralheira, sobretudo, após a publicação dos Contos da Mamãe Gansa, do escritor francês, do século XVII, Charles Perrault. Na realidade, as transformações dessa narrativa são tão variadas, quanto necessárias, pois funcionam como aparelhos que sinalizam importantes mudanças sociais e, neste caso, apontam para as conquistas femininas nos mais variados âmbitos. Assim, o nosso trabalho, à luz dos pressupostos teóricos da Análise de Discurso, busca analisar as vozes que ecoam no contoA Cinderela mudou de ideia, de Nunila López Salamero (2009, evidenciando as vontades de verdade acerca da identidade dos sujeitos mulher e homem que desse conto fazem sítio.Palavras-chave: Dialogismo. Intertextualidade. Vontades de Verdade. Paródia. DiscursoAbstractDialogism shows itself as the basis of all discursivity, since every enunciation containing discursive materiality, has a universe of social voices in multiple relationships of convergence and divergence, of harmony and conflict, of acceptance and refusal. Starting from this principle, the text, as an enunciation, is understood with the aid of literary

  10. DIALOGISMO E VONTADES DE VERDADE NA DISCURSIVIDADE DA CINDERELA

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    Maria Angélica de Oliveira

    2016-01-01

    Full Text Available O dialogismo apresenta-se como fundamento de toda a discursividade; pois, considere-se que todo enunciado, enquanto materialidade discursiva abriga um universo de vozes sociais em múltiplas relações de convergência e de divergência, de harmonia e de conflito, de aceitação e de recusa. Partindo desse princípio, o texto, na sua qualidade de enunciado, é compreendido, no seio dos estudos literários, como uma voz que dialoga com outros textos, funcionando também como ecos das vozes de seu tempo, de sua história, revelando os valores, as crenças, as vontades de verdade de uma dada formação social. A partir dessa perspectiva, trazemos uma releitura de um tradicional conto popular de origem de língua românica europeia que ficou conhecido em todo o mundo como a história da Cinderela ou da GataBorralheira, sobretudo, após a publicação dos Contos da Mamãe Gansa, do escritor francês, do século XVII, Charles Perrault. Na realidade, as transformações dessa narrativa são tão variadas, quanto necessárias, pois funcionam como aparelhos que sinalizam importantes mudanças sociais e, neste caso, apontam para as conquistas femininas nos mais variados âmbitos. Assim, o nosso trabalho, à luz dos pressupostos teóricos da Análise de Discurso, busca analisar as vozes que ecoam no contoA Cinderela mudou de ideia, de Nunila López Salamero (2009, evidenciando as vontades de verdade acerca da identidade dos sujeitos mulher e homem que desse conto fazem sítio.Palavras-chave: Dialogismo. Intertextualidade. Vontades de Verdade. Paródia. DiscursoAbstractDialogism shows itself as the basis of all discursivity, since every enunciation containing discursive materiality, has a universe of social voices in multiple relationships of convergence and divergence, of harmony and conflict, of acceptance and refusal. Starting from this principle, the text, as an enunciation, is understood with the aid of literary

  11. Una manera de nombrar el deseo en Toda esa gran verdad

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    Mauricio List

    2011-01-01

    Full Text Available Este artículo analiza la novela Toda esa gran verdad (2006 del mexicano Eduardo Montagner. El artículo centra su atención en el tema de la sexualidad, particularmente la del personaje principal. La idea es reflexionar acerca de formas disidentes de la sexualidad que rompen con las maneras normativas y que son sancionadas socialmente. En este caso en particular, unas botas de hule son el centro de la atención de un joven de una comunidad rural que dice estar enamorado del dueño de dicho calzado. Él va aprendiendo que un sujeto fetichista requiere de su objeto para disfrutar del placer erótico.

  12. Gasohol : un combustible limpio para Colombia

    OpenAIRE

    Ocampo González, Aquiles

    1998-01-01

    Se describe un estudio sobre las posibilidades reales que tiene Colombia de establecer un programa masivo para utilizar mezclas de etanol y gasolina como combustible automotor, teniendo en cuenta que la materia prima más probable deberá ser la caña de azúcar. Se discuten los efectos ambientales, socioeconómicos y técnicos de dicho programa.

  13. Žižek AVEC HABERMAS: EL PROBLEMA DE LA VERDAD Y LA IDEOLOGÍA

    OpenAIRE

    Ricardo Camargo Brito

    2010-01-01

    La tesis principal de este trabajo sostiene que la noción lacaniana de “lo real” o “reprimido primordial”, reformulada por Žižek, resituaría los límites teóricos de la acción comunicativa de Habermas y, al mismo tiempo, permitiría acuñar una verdad hipotética, pero de todas formas universal, indispensable para una nueva crítica ideológica.

  14. La comunicación: entre la verdad y la mentira

    Directory of Open Access Journals (Sweden)

    Alfredo Mason

    2011-06-01

    Full Text Available La transformación de los medios de comunicación en factores de poder es acompañada con la aparición de una metodología para construir una realidad ficcional, como herramienta de manipulación y construcción de un discurso hegemónico cuyo objetivo es el control social. La comunicación de la verdad pierde su sentido ético y se transforma en mercadería, donde la espectacularización del mensaje ocupa el lugar del valor del contenido.El discurso hegemónico se contrapone con un sistema democrático de gobierno, este último requiere la aparición de una pluralidad de información que permita a la opinión pública decidir libremente.

  15. "La verdad sobre las empresas familiares"

    OpenAIRE

    Chavez Partida, Ma. Guadalupe

    2011-01-01

    En este trabajo se estudia principalmente, el cuidar el proyecto de la sucesión de la empresa a los familiares más jóvenes y para lo cual también se plantean algunas propuestas utilizando el modelo de los tres círculos. El modelo de los tres círculos ha tenido gran aceptación porque combina una elegancia teórica y una aplicabilidad inmediata. Es una herramienta muy útil para entender la fuente de los conflictos interpersonales, los roles, las prioridades y los límites de las empresas familiar...

  16. Hermenêutica e saúde: reflexões sobre o pensamento de Hans-Georg Gadamer

    Directory of Open Access Journals (Sweden)

    Janieiry Lima de Araújo

    2012-02-01

    Full Text Available Este artigo tem como objetivo contribuir para a utilização da hermenêutica de Gadamer na prática de enfermagem. Reflete acerca da incorporação do paradigma conceitual sobre a saúde, o cuidado e o diálogo terapêutico. Na primeira parte, apresenta a discussão dos conceitos Gadamerianos da obra Verdade e Método, a filosofia hermenêutica proposta pelo filósofo e finaliza com a articulação do conceito de saúde apresentado na obra O Caráter Oculto da Saúde, que propõe o cuidado mediado pelo diálogo terapêutico e sua utilização pelos profissionais de enfermagem.

  17. The fuel cells: Truths on the generation of clean and efficient electricity electrochemical way; Las celdas de combustible: Verdades sobre la generacion de electricidad limpia y eficiente via electroquimica

    Energy Technology Data Exchange (ETDEWEB)

    Cano Castillo, Ulises [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In the search of alternative technologies for the generation of electrical energy, the Instituto de Investigaciones Electricas (IIE) has put special attention in a technology that promises to be key in the next years: The fuel cells, it is for this reason that in this article a review of this type of cells is presented, as well as its basic characteristics and benefits as a result of its use for the generation of electrical energy. [Spanish] En la busqueda de tecnologias alternativas de generacion de energia electrica, el Instituto de Investigaciones Electricas (IIE) ha puesto atencion especial en una tecnologia que promete ser clave en los proximos anos: Las celdas de combustible, es por ello que en este articulo se presenta una resena de este tipo de celdas, asi como sus caracteristicas principales y beneficios como resultado de su utilizacion para la generacion de energia electrica.

  18. Sujeto y verdad en el prólogo de la Fenomenología del espíritu, de Guillermo Federico Hegel

    Directory of Open Access Journals (Sweden)

    Rodolfo García Aguilar

    2013-07-01

    Full Text Available La relación entre sujeto y verdad tiene una relación que se establece dentro de los parámetros del idealismo trascendental hegeliano, puesto que sobrepasan la forma usual de presentar el conocimiento como una relación unilateral entre el sujeto y el objeto. En Hegel la relación es dialéctica en cuanto a que el sujeto, la conciencia y el “en sí” deben integrarse con el “ser ahí”, para que, en un movimiento de integración, se consolide la verdad. Representa el movimiento que la conciencia debe realizar de salir de sí, para integrarse con su objeto y captar el movimiento. El sujeto y el objeto no son considerados como cosas, sino como momentos de ese movimiento que es la dialéctica.

  19. El PRT-La Verdad entre los trabajadores de la carne de Berisso: La agrupación El Activista de la Carne y la Lista Gris (1967-1972)

    OpenAIRE

    Castillo, Christian

    2011-01-01

    Este trabajo se enmarca dentro de un proyecto más general referido al estudio de los conflictos obreros y estudiantiles y las estrategias de la izquierda en La Plata y Gran La Plata entre 1966 y 1973 y, más en particular, del estudio de la actividad en la región durante ese período del PRT-La Verdad. De las dos fracciones en las que se escindió el Partido Revolucionario de los Trabajadores a comienzos de 1968, el sector encabezado por Nahuel Moreno ?que pasó a denominarse "PRT-La Verdad"- fue...

  20. Subjetividade e verdade no último Foucault Subjectivity and truth in the late Foucault

    Directory of Open Access Journals (Sweden)

    Cesar Candiotto

    2008-01-01

    Full Text Available A constituição do sujeito na investigação do último Foucault geralmente é conhecida pela perspectiva de sua estética da existência. Tal abordagem deve-se sobremaneira à leitura dos dois últimos volumes de Histoire de la sexualité (1984. No entanto, o presente artigo aponta que nos cursos no Collège de France intitulados Subjectivité et verité (1981 e L'herméneutique du sujet (1982 outra leitura pode ser elaborada. A relação entre subjetividade e verdade evidencia-se como central em seu pensamento e seus desdobramentos são apresentados a partir das diferenças estabelecidas entre filosofia e espiritualidade, das articulações entre cuidado de si e conhecimento de si, conhecimentos úteis e inúteis, cuidado de si e conversão a si, ascese e verdade.The constitution of the subject in the investigation of the late Foucault is generally dealt with through the perspective of his aesthetics of existence. Such approach is mainly due to the reading of the two last volumes of The History of Sexuality (1984. However, the present article points out that in his Collège de France courses entitled Subjectivity and Truth (1981 and The Hermeneutics of the Subject (1982, a different reading can be elaborated. The relation between subjectivity and truth is evidently central in his thinking and its developments are presented from the differences established between philosophy and spirituality, from the articulations between care of the self and knowledge of the self, useful knowledge and useless knowledge, care of the self and conversion to the self, asceticism and truth.

  1. ¿Qué es en verdad el dinero? Una teoría sobre la naturaleza del dinero

    OpenAIRE

    Ramos-Arévalo, J.M. (Javier María)

    2008-01-01

    Sorprende descubrir que no hay una definición de dinero que sea admitida deforma universal. No hay una explicación de la naturaleza del dinero que justifique todas sus funciones y características. Este trabajo pretende demostrar que el dinero es ante todo un derecho, y que considerarlo un derecho nos puede permitir aclarar los enigmas del dinero. Existe bastante acuerdo sobre para qué surge el dinero, pero debemos preguntarnos el cómo, y a partir del ahí explicar de dónde le vi...

  2. Leer y releer a Francisco Umbral en la era de la posverdad

    OpenAIRE

    Vigneron, Denis

    2017-01-01

    Este artículo aporta une reflexión sobre la relación de Umbral con la verdad. Basándonos en una serie de artículos de prensa, nos proponemos estudiar cómo el escritor y periodista consigue dar cuenta de una verdad objetiva de los hechos sin pasar por el tamiz subjetivo de lo que hoy se llama posverdad: concepto que define ahora las condiciones de la producción de información. Comparando contextos de escritura distintos –el de Umbral y el de hoy– nos interrogamos sobre los peligros de la de...

  3. O DIREITO À MEMÓRIA E À VERDADE NO BRASIL PÓS-DITADURA CIVIL-MILITAR

    OpenAIRE

    Carlos Artur Gallo

    2010-01-01

    O presente estudo analisa em que consiste, como surge e quais as possibilidades de concretização do “direito à memória e à verdade” na realidade brasileira. Concebido como mecanismo de reconciliação das sociedades que tenham passado por experiências traumáticas (assim chamadas em virtude da reiterada violação aos direitos humanos que foi consumada nas mesmas), este direito consiste, basicamente, no resgate da memória e da verdade dos fatos referentes às trajetórias daqueles que foram persegui...

  4. Magnox Fuel Cycles; Cycles des combustibles gaines de magnox; Toplivnye tsikly magnoks; Ciclos de combustible magnox

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

    1963-10-15

    esquemas de irradiacion que se producen segun los diversos programas de carga del combustible, y describe someramente los metodos de calculo utilizados en la actualidad. Compara diversos programas de carga continua o intermitente del combustible. Estudia el problema de la irradiacion eficiente de la primera carga, junto con los metodos de reabastecimiento retardado y de transposicion de los elementos combustibles. Discute las ventajas economicas y los problemas que plantea la utilizacion de uranio, no natural en reactores de flujo nivelado. Formula consideraciones de orden practico sobre la carga de combustible durante la marcha en reactores nuevos y hace referencia a la experiencia adquirida en Bradwell y en Berkeley. Describe someramente el efecto que ejercen las variaciones del costo del combustible y de su resistencia sobre los aspectos economicos del ciclo de combustible. (author) [Russian] Rassmatrivaetsya vzaim o zavisimost' mezhdu potokom izlucheniya i temperaturnym raspredeleniem i kharakteristikami oblucheniya, vyzvannaya razlichnoj praktikoj zameny topliva, opisyvayutsya sushchestvuyushchie metody rascheta. Provoditsya sravnenie razlichnykh skhem zameny topliva, vklyuchaya kak sistemu vygruzki topliva portsiyami, tak i sistemu nepreryvnoj vygruzki. Problema ehffektivnogo oblucheniya pervoj zagruzki rassmatrivaetsya vmeste so skhemami zapazdyvayushchej nachal'noj zameny topliva i ego peremeshcheniya. Rassmatrivayutsya ehkonomicheskie preimushchestva i trudnosti ispol'zovaniya neprirodnogo urana v vyrovnennykh reaktorakh. Rassmatrivaetsya prakticheskoe reshenie skhemy zameny topliva na novykh reaktorakh i delaetsya ssylka na opyt, priobretennyj v Braduehlle i Berkli. Opisyvaetsya vliyani razlichnoj stoimosti topliva i prodolzhitel'nosti kampanii za ehkonomichnost' toplivnogo tsikla. (author)

  5. Dr. Antonio María Béguez César (1895-1975: del plagio a la verdad histórica

    Directory of Open Access Journals (Sweden)

    María Antonia Peña Sánchez

    2014-05-01

    Full Text Available En este artículo se ofrecen evidencias documentales que fundamentan la verdad histórica de la precedencia del Dr. Antonio María Béguez César en el descubrimiento de la neutropenia crónica maligna familiar con granulaciones atípicas de los leucocitos, comúnmente divulgada como síndrome de Chédiak-Higashi; razón por la cual los aportes del médico cubano resultan prácticamente invisibles para la comunidad científica nacional y extranjera, y para el pueblo al que tanto sirvió. El actual documento forma parte del Proyecto Ramal, con el objetivo de proporcionar una mayor visibilidad a la vida y obra del ilustre pediatra santiaguero, quien describió el cuadro clínico de una enfermedad hasta entonces desconocida, pero luego divulgada de muy diversas maneras para confundir a la comunidad científica en cuanto a su legítimo autor. Del mismo modo se presentan fragmentos de la información publicada sobre el hallazgo, así como bibliografía actualizada, novedosa y fidedigna respecto a tan importante y controvertido asunto. Por último, se abordan otros aspectos personales y profesionales del Dr. Béguez César -- considerado como el Padre de la Pediatría en las provincias orientales de Cuba --, cuyos extraordinarios méritos le hacen acreedor de figurar perpetuamente entre las personalidades insignes de la ciencia cubana

  6. Algunas consideraciones y perspectivas sobre el test de razonabilidad: tras las huellas de las víctimas en el sistema de verdad, justicia y reparación de derechos

    Directory of Open Access Journals (Sweden)

    LUIS RICARDO GÓMEZ-PINTO

    2011-01-01

    Full Text Available El presente ensayo pretende analizar la influencia que la figura del test de razonabilidad de los derechos fundamentales tiene hoy en el sistema de reincorporación de grupos al margen de la ley que adopta la Ley 975 del 2005. La jurisprudencia, y las demás fuentes recurridas, invitarán a hacer un análisis del problema a partir del apoyo conjunto de instrumentos de la política criminal y el análisis constitucional, con el fin de reconstruir la teoría en la cual se apoyan dichas normas en Colombia. Esto llevará a enfrentar, académicamente, la teoría y la política criminal que se han venido aplicando hasta hoy, frente a la Ley 975 del 2005 de verdad, justicia y reparación. O lo que será el planteamiento de una justicia retributiva frente a una restaurativa.

  7. Combustibles más limpios. Oxidar el azufre con agua oxigenada

    OpenAIRE

    Heraldo de Aragón

    2017-01-01

    Eliminar los compuestos de azufre de los combustibles mediante el empleo de agua oxigenada. Este es el planteamiento de un prometedor sistema catalítico heterogéneo, ‘made in Aragón’, que podría minimizar los efectos perjudiciales de los combustibles sobre la salud y el medio ambiente. Este desarrollo, realizado en el ISQCH en colaboración con la empresa productora de agua oxigenada Peroxychem Spain, ubicada en La Zaida, es uno de los artículos científicos de ingeniería química más citados de...

  8. JOGO DA VERDADE QUÍMICO: UMA NOVA METODOLOGIA PARA O ENSINO DE TERMODINÂMICA

    Directory of Open Access Journals (Sweden)

    Nara Rúbya Sousa

    2011-02-01

    Full Text Available Com os novos avanços científicos e tecnológicos, o Ensino de Ciências, sobretudo de Química, tem sentido cada vez mais a necessidade de utilizar novas técnicas de ensino. A utilização das atividades lúdicas no ensino de ciências pode suprir estas necessidades contribuindo para uma mudança no ensino tradicional, tornando-o mais dinâmico, interativo, atrativo e interessante. Com base nisto, em nossa pesquisa, nos propomos desenvolver um jogo intitulado: Jogo Da Verdade Químico, a fim de facilitar o processo ensino-aprendizagem e avaliar o aprendizado em relação aos conceitos de Termodinâmica.

  9. Hablar desde el silencio: El silencio como verdad en las narrativas de mujeres sobrevivientes

    Directory of Open Access Journals (Sweden)

    Karin Davidovich

    2015-01-01

    Full Text Available A partir del estudio de testimonios y entrevistas personales con ex detenidas-desaparecidas de la última dictadura militar en Argentina sostengo que, si bien todos los testimonios del horror están impregnados por la presencia del silencio, los testimonios de sobrevivientes argentinas que comienzan a surgir masivamente desde los  noventa contienen dos aspectos fundamentales que los distinguen de otros. El primero es que sugieren una diferencia importante entre dos tipos de silencio, uno mudo y el otro elocuente.  Y el segundo es que llaman a un interlocutor capaz de escuchar sus silencios elocuentes. De este modo los silencios en estas narrativas testimoniales no encubren una verdad, sino que son ellos mismos la verdad. La mujeres asociadas históricamente con el silencio, se presentan como las indicadas para hacer de este no lo opuesto al lenguaje, sino el lenguaje mismo como lenguaje del trauma, invitándonos a leer el silencio, a descifrarlo, a leer más allá de las palabras, a entrenar el oído para escuchar "los indicios" de la verdad, aceptando la imposibilidad de capturar el significado de estas experiencias del horror en su totalidad. Sin embargo, esta imposibilidad no implica una parálisis, un  punto final, sino que llama a la necesidad de “trabajar” ese silencio, agregándole valor, con el fin de transformar tanto la identidad de la víctima como la de la sociedad misma, creando oyentes empáticos y nuevos modos de ciudadanía Through the study of testimonial texts and personal interviews of women survivors of the last dictatorship in Argentina, I argue that while all testimonies of horror are permeated by the presence of silence, women’s testimonial productions from the nineties present two important aspects that differentiate them from other testimonies. The first one is that they suggest a difference between two types of silences in their narratives, one that is mute and another one that is eloquent. The second aspect

  10. FELICIDAD Y VERDAD EN SAN AGUSTÍN Y TARKOWSKY

    Directory of Open Access Journals (Sweden)

    Claudio Pierantoni

    2006-01-01

    Full Text Available Este trabajo evidencia y analiza uno de los logros mayores del pensamiento no solo agustiniano, sino universal: la relación entre la noción y búsqueda de la verdad por un lado, y la noción y búsqueda de la felicidad por el otro, y lo ilustra en relación con la película "Stalker" de Tarkowsky. Culminación del pensamiento metafísico antiguo, esta síntesis antropológica y ontológica es presentada en su valor perenne, abierta sí a ulterior perfeccionamiento, pero muy clara en prevenir contra algunos errores básicos recurrentes en las diferentes etapas del pensamiento humano, y presentes hasta hoyThis paper is intended to show and analyze one of the foremost achievements of Augustinian, and universal thinking: the relation between the notion and search for Truth on the one side, and the notion and search for Happiness on the other, and sets it in a comparison with Tarkowsy's film, Stalker. Culmination of ancient metaphysical thinking, this anthropological and ontological synthesis is presented in its permanent validity, open to further development, but very clear in preventing against basic mistakes to be found at all stages of human thinking, up to present day

  11. Impact of the use of alternative fuels on clinker reactivity; Impacto del uso de combustibles alternativos sobre la reactividad del clínker

    Energy Technology Data Exchange (ETDEWEB)

    Serrano-González, K.; Reyes-Valdez, A.; Chowaniec, O.

    2017-07-01

    The use of alternative fuels in the cement industry has increased its relevance in the past decades due to their ecological and economic benefits. In concert with the efforts to increase its use, several studies have focused on their potential impact with respect to clinker reactivity and how they could affect the expected physical and mechanical properties. This work studied the effects of five alternative fuels on the reactivity of eight industrial clinker samples, considering several analytical techniques. Differences were identified among the clinker samples after replacing the alternative fuels, mainly with simultaneous eliminations, as in samples S4, S5 and S8. The modifications were related to the polymorph, size and reactivity of tricalcium silicate and to the clinker profile during the hydration process, due to the SO3 consumption rate. These changes were expressed in the higher compressive strengths in comparison with the original reference clinker. [Spanish] El uso de combustibles alternativos en la industria cementera ha ido en incremento en las últimas décadas debido a su beneficio ecológico y económico. En línea con los esfuerzos enfocados en incrementar su uso, se han realizado distintos estudios enfocados en determinar su impacto potencial en la reactividad del clínker y en cómo pueden afectar sus propiedades físicas y mecánicas. Este trabajo estudia el efecto de cinco combustibles alternos sobre la reactividad de ocho muestras industriales de clínker, considerando diferentes técnicas analíticas. Se identificaron diferencias principalmente cuando se realizaron eliminaciones simultáneas de varios combustibles, como en las muestras S4, S5 y S8. Las modificaciones se basan en un cambio en el polimorfo, tamaño y reactividad del silicato tricálcico y del perfil de hidratación de los clínkeres, relacionado con el ritmo del consumo del SO3. Las modificaciones se reflejaron en un incremento en la resistencia a la compresión.

  12. INTERROGACIONES SOBRE EL VALOR DE LA PALABRA. Violencia y narración.INTERROGAÇÕES SOBRE O VALOR DA PALAVRA. Violência e narraçãoQUESTIONINGS ABOUT THE VALUE OF WORDS. Violence and narratives

    Directory of Open Access Journals (Sweden)

    Valentina Isolda Salvi

    2010-06-01

    Full Text Available O  artigo ocupa-se da palavra dos perpetradores pois o interés é analisar a  evocação da violencia do punto de vista de quem cometeu actos atroces. Nesse  sentido, o propósito é refletir sobre os problemas éticos e teóricos que  manifestan-se na tarefa da pesquisa na hora de interpretar a memória dos  perpetradores em “primeira pessoa”, assim como as dificuldades que poden-se  apresentar no espaço da fala e nas condições da  escuta quando esses relatos acontecem. Como taes narrativas excedem os  conceitos e categorias teóricas a nossa disposição, o desafio é construir um  marco para o análise esses discursos. Tambén o artigo propõe-se  a refletir sobre a posição subjetiva dos pesquisadores em historia oral  atendendo as dificuldades que essas narrativas podem producir em quem as  escuta. Por último, se abordaram  os  debates académicos sobre o valor do testemunho, por um lado, e sobre as conffecções  dos repressores e torturadores nas Comissões de Verdade e Reconciliação, por  outro. Palavras-Chave: Violencia.  Narrativa. Perpetradores. Trauma. Memória.   Resumen Este artículo se ocupa de la palabra de los  perpetradores puesto que se propone analizar la evocación de la violencia desde  el punto de vista de quienes cometieron actos atroces. En tal sentido, el  interés es reflexionar sobre los problemas éticos y teóricos que se manifiestan en  la tarea de investigación a la hora interpretar la memoria de los perpetradores  en “primera persona”, así como también busca pensar las dificultades que se  presentan en el espacio de escucha e interlocución cuando estos relatos tienen  lugar. Como estas narrativas exceden los conceptos y categorías teóricas a  nuestra disposición, el desafío es construir un marco desde el cual analizar  estos discursos. Además se propone reflexionar sobre la posición subjetiva de  los investigadores en historia oral dadas las dificultades que

  13. Estudio comparativo de las diferentes tecnologías de celdas de combustible

    Directory of Open Access Journals (Sweden)

    Alvarado-Flores, J.

    2013-06-01

    Full Text Available Fuel cells generate electricity and heat during electrochemical reaction which happens between the oxygen and hydrogen to form the water. Fuel cell technology is a promising way to provide energy for rural areas where there is no access to the public grid or where there is a huge cost of wiring and transferring electricity. In addition, applications with essential secure electrical energy requirement such as uninterruptible power supplies (UPS, power generation stations and distributed systems can employ fuel cells as their source of energy. The current paper includes a comparative study of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells. In addition, techno-economic features of hydrogen fuel cell vehicles (FCV and internal combustion engine vehicles (ICEV are compared. The results indicate that fuel cell systems have simple design, high reliability, noiseless operation, high efficiency and less environmental impact. The aim of this paper is to serve as a convenient reference for fuel cell power generation reviews.Las celdas de combustible generan electricidad y calor durante la reacción electroquímica que ocurre entre el oxígeno e hidrógeno para formar agua. La tecnología de la celda de combustible es un camino prometedor para proporcionar energía en áreas rurales, donde no hay acceso a la red eléctrica pública, o donde hay un costo enorme en el cableado y transferencia de electricidad. Además, las celdas de combustible, pueden emplearse como fuente de energía, para asegurar la energía eléctrica como por ejemplo, en fuentes de potencia ininterrumpida (uninterruptible power supplies, UPS, estaciones de generación de energía y sistemas de distribución. En este artículo, se hace un estudio comparativo sobre diseño básico, principios de funcionamiento, aplicaciones, ventajas y desventajas de las diversas tecnologías disponibles para celdas de

  14. O mundo natural e o erotismo das gentes no Brasil Colônia: a perspectiva do estrangeiro

    Directory of Open Access Journals (Sweden)

    Jean Marcel Carvalho França

    Full Text Available O ensaio aborda a literatura de viagem sobre o Brasil, escrita ao longo dos séculos XVI, XVII e XVIII, com o intuito de extrair daí uma pequena amostra da imagem que o europeu construiu do mundo natural e de um dos aspectos da conduta moral das gentes dos trópicos portugueses, aquele ligado à vida erótica do brasileiro, à sua relação com os prazeres da carne. Trata, pois, de uma tentativa muita limitada de mapear uma pequena parte das verdades sobre o Brasil e suas gentes que o europeu construiu e partilhou ao longo dos séculos, verdades que, em larga medida, guiaram as suas ações nesta parte do globo.

  15. Sobre Escravidão no Império Romano (152 documentos epigráficos

    Directory of Open Access Journals (Sweden)

    Glória Portal

    1983-06-01

    Full Text Available (primeiro parágrafo do artigo É verdade que crescem dia a dia a consciência e a sensibilidade quanto às formas de ultraje à pessoa humana, entre elas a escravidão. O interesse é cada vez maior por documentos e estudos esclarecedores da trajetória do escravismo, reveladores do aprofundamento, fortalecimento e nuanças deste sistema. As províncias romanas não conheceram na mesma amplitude a difusão do sistema escravista, o que implica em diferenças essenciais entre elas quanto aos modos de exploração.  Prosseguimos agora estudos iniciados há alguns anos sobre a escravidão numa região determinada do Império Romano: a Dácia.  Nosso objetivo é o de procurar, principalmente através de toda a série documental epigráfica existente sobre escravidão na Província Dácia de Trajano (152 documentos, discernir em que medida o sistema escravista penetrou nesta província e quais os tipos de relações de produção que estão se estabeleceram. Até aqui inexistia tradução portuguesa dos documentos mencionados acima; isto é um argumento forte a nos impulsionar no presente estudo; além de outras razões.

  16. The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

    Energy Technology Data Exchange (ETDEWEB)

    Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

  17. The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

    Energy Technology Data Exchange (ETDEWEB)

    Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

  18. Uma Análise sobre o Mercado Mundial do Biodiesel

    Directory of Open Access Journals (Sweden)

    Dario Oliveira Lima

    2014-12-01

    Full Text Available O combustível fóssil, base da matriz energética mundial, dá sinais de esgotamento das suas reservas e saturação ambiental por causa do aquecimento global. Surgiu assim um novo desafio para a Academia: encontrar um combustível substituto que seja renovável e não emita Dióxido de Carbono. O biodiesel surgiu como potencial substituto do combustível fóssil que se esgotará dentro de 50 anos. O mercado mundial de biodiesel está em expansão e demanda por informações econômicas referentes ao bicombustível. Este trabalho se propõe a realizar um levantamento sobre as informações de mercado do biodiesel e seu desenvolvimento no mundo. Traz informações relativas à produção, à capacidade produtiva e aos incentivos fiscais do biodiesel em diversos países do mundo.

  19. Estudio de las modificaciones a introducir en un automóvil que incorpore la tecnología de pila de combustible

    OpenAIRE

    Sánchez Portillo, Daniel

    2005-01-01

    Este proyecto realiza un estudio sobre la tecnología de pilas de combustible de hidrógeno como sistema energético capaz de sustituir a las fuentes de energía convencionales, afrontar la disminución de las reservas existentes de combustibles fósiles y disminuir los efectos del cambio climático reduciendo la emisión de contaminantes tóxicos a la atmósfera. Se analiza la metodología de funcionamiento de las pilas de combustible, sus principales componentes y las diversas tipologías e...

  20. Combustion

    CERN Document Server

    Glassman, Irvin

    2008-01-01

    Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

  1. Uma Comissão da Verdade no Brasil? Desafios e perspectivas para integrar direitos humanos e democracia

    Directory of Open Access Journals (Sweden)

    Raphael Neves

    2012-01-01

    Full Text Available Este artigo busca avaliar a criação da Comissão Nacional da Verdade no Brasil e o esforço desta para integrar direitos humanos e meios democráticos de apurar violações passadas. Primeiramente, ele tenta estabelecer uma visão normativa de acordo com a qual a Lei de Anistia de 1979 não é válida porque viola o que Rainer Forst chama de "direito básico à justificação". Além disso, revê e critica à fundamentação normativa das decisões da Corte Interamericana de Direitos Humanos, que recentemente condenou o Estado brasileiro. De acordo com a visão dessa corte, o único modo legítimo que um país tem de apurar violações de direitos humanos é via justiça criminal. Essa perspectiva, o artigo argumenta, é muito estreita e deve incluir também as comissões da verdade.This paper aims to evaluate the creation of the National Truth Commission in Brazil and its effort to integrate human rights and democratic means to account past violations. First, it tries to establish a normative view according to which the Amnesty Law enacted in 1979 is not valid because it violates what Rainer Forst calls a "basic right to justification". In addition it reviews and challenges the normative foundations of the decisions of the Inter-American Court of Human Rights, which recently condemned the Brazilian state. According to the Court's view, the only legitimate way a country has to make violations of human rights accountable is by means of criminal justice. This perspective, the article argues, is too narrow and must include truth commissions as well.

  2. Combustion

    CERN Document Server

    Glassman, Irvin

    1997-01-01

    This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

  3. Basic logic for true and false LBVF Lógica básica para la verdad y la falsedad LBVF

    Directory of Open Access Journals (Sweden)

    Manuel Sierra A

    2007-12-01

    Full Text Available System LBVF is an extension of the classical positive logic, the system includes operators of alternating affirmation, alternating negation and determinability, and the operators of classical negation and good foundation are defined as from them. The system is characterized by a semantic of traditional valuations. Respect to the negation and affirmation operators the system is paracomplete.In the system the definitions of truth and falsity presented by Aristotle are really characterized, representing the Aristotelian falsity with the operator of alternating negation and the Aristotelian truth with the operator of alternating affirmation. This interpretation gives solution to a variant of the liar’s paradox.El sistema LBVF se construye como una extensión de la lógica clásica positiva, al incluir operadores de afirmación alterna, negación alterna y completez, además, se definen a partir de ellos los operadores de negación clásica y buena fundamentación. El sistema es caracterizado por una semántica de valuaciones tradicionales con la cual se prueba que, respecto a los operadores de afirmación y de negación alterna el sistema es paracompleto. En el sistema se caracterizan las definiciones de verdad y falsedad presentadas por Aristóteles, representando la falsedad aristotélica con el operador de negación alterna y la verdad aristotélica con el operador de afirmación alterna, lográndose con esta interpretación dar solución a una variante de la paradoja del mentiroso.

  4. El cardo, el ave y la verdad. Entrevista con el pintor Antonio López

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Peynot

    2016-01-01

    Full Text Available Antonio López es reconocido como uno de los más grandes pintores actuales por numerosas instituciones y por un público muy amplio. Al escoger pintar su entorno más cercano, de manera realista y sin imponer siquiera un estilo, supo que su camino sería difícil y solitario, lejos de los críticos de arte, curadores, galeristas y otros actores de la escena contemporánea. De la fidelidad de su mirada nació una obra, y de esta obra nació el pintor, que nos habla en esta entrevista, al horizonte de una verdad. Entre otros reconocimientos Antonio López recibió el Premio Príncipe de Asturias de las Artes en 1985 y el Premio Velázquez de Artes Plásticas en 2006.

  5. A lógica do consumo

    Directory of Open Access Journals (Sweden)

    Tiago Eloy Zaidan

    2017-06-01

    Full Text Available Referência da obra resenhada: LINDSTROM, Martin. A lógica do consumo: verdades e mentiras sobre por que compramos. Tradução: Marcello Lino. Rio de Janeiro: Harper Collins Brasil, 2016.

  6. Princípio de razão e o “conhecimento das causas”: considerações sobre o valor fundamental da verdade e o seu sentido = Principle of reason and “knowledge of causes”: considerations on the inner value of truth and its meaning

    Directory of Open Access Journals (Sweden)

    Moraes, Dax

    2013-01-01

    Full Text Available As críticas nietzscheanas dos valores e da verdade dirigem-se a um tipo da vontade que exige do mundo uma causa universal que lhe sirva como explicação. O presente ensaio concentra-se no significado fundamental desse sentimento comum à ciência e à religião enquanto resposta à total ausência de sentido, uma vez que o sentido de cada coisa, na existência, não se deve a nada mais senão à nossa própria criação

  7. Una verdad "incómoda"… que es preciso difundir y frente a la que hay que actuar urgentemente

    Directory of Open Access Journals (Sweden)

    Educadores por la Sostenibilidad

    2007-04-01

    Full Text Available Al Gore será recordado, muy probablemente, no tanto por haber sido vicepresidente de EEUU junto a Bill Cinton o por perder la presidencia frente a George Bush (pese a haber obtenido más votos, sino por sus preocupaciones en torno a la degradación del medio ambiente y la supervivencia de la especie humana que le han llevado recientemente, en particular, a difundir “An inconvenient truth” (una verdad incómoda: la gravedad de un cambio climático ya en marcha, sus causas y la necesidad de hacerle frente con la mayor urgencia

  8. Crônica política sobre um documento contra a "ditabranda"

    Directory of Open Access Journals (Sweden)

    Caio Navarro de Toledo

    2009-10-01

    Full Text Available Este breve artigo, uma crônica política, examina o significado e os efeitos políticos e ideológicos de um abaixo-assinado criado na Internet, em fevereiro de 2009. "Repúdio e Solidariedade" questionou a utilização do termo "ditabranda" - difundido pelo jornal paulista Folha de S. Paulo para designar a ditadura militar brasileira -, bem como prestou solidariedade a dois acadêmicos e intelectuais da Universidade de São Paulo (USP, conhecidos por suas atuações em defesa dos direitos humanos no Brasil. Subscrito por mais de 8 mil signatários, em pouco mais de seis semanas, o abaixo-assinado pode ser considerado - como testemunham os extensos comentários nele contidos - um relevante documento na luta pelo direito à verdade e à justiça sobre os fatos ocorridos durante o regime militar brasileiro (1964-1985. Talvez o seu papel simbólico mais relevante seja o de ter fincado uma bandeira na luta ideológica em torno da memória sobre 1964. No centro dessa bandeira seria reinscrita - como propôs um dos signatários do documento - a antiga consigna: no pasarán. Ou seja, os setores democráticos e progressistas da sociedade brasileira que apoiaram "Repúdio e Solidariedade" afirmam que não aceitarão calados as "falsificações da história" que impliquem o insulto à memória dos que lutaram, foram torturados e morreram na luta pela redemocratização do país.

  9. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  10. Estudio del Efecto de la Altitud sobre el Comportamiento de Motores de Combustión Interna. Parte 1: Funcionamiento

    OpenAIRE

    Lapuerta, Magín; Armas, Octavio; Agudelo, John R; Sánchez, Carlos A

    2006-01-01

    En este trabajo se estudia el efecto de la altitud sobre la potencia en motores de aspiración natural y turbosobrealimentados sin sistemas correctores, en función de la presión ambiental. La altitud sobre el nivel del mar tiene un notable efecto sobre la densidad del aire y su composición. Dado que los motores de combustión interna tienen sistemas de admisión y de inyección de combustible volumétricos, la altitud modifica el ciclo termodinámico de operación, y en consecuencia las prestaciones...

  11. Alternate fuels; Combustibles alternos

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana. Iztapalapa (Mexico)

    2003-07-01

    In the definition and description of alternate fuels we must center ourselves in those technological alternatives that allow to obtain compounds that differ from the traditional ones, in their forms to be obtained. In this article it is tried to give an overview of alternate fuels to the conventional derivatives of petroleum and that allow to have a clear idea on the tendencies of modern investigation and the technological developments that can be implemented in the short term. It is not pretended to include all the tendencies and developments of the present world, but those that can hit in a relatively short term, in accordance with agreed with the average life of conventional fuels. Nevertheless, most of the conversion principles are applicable to the spectrum of carbonaceous or cellulosic materials which are in nature, are cultivated or wastes of organic origin. Thus one will approach them in a successive way, the physical, chemical and biological conversions that can take place in a production process of an alternate fuel or the same direct use of the fuel such as burning the sweepings derived from the forests. [Spanish] En la definicion y descripcion de combustibles alternos nos debemos centrar en aquellas alternativas tecnologicas que permitan obtener compuestos que difieren de los tradicionales, al menos en sus formas de ser obtenidos. En este articulo se pretende dar un panorama de los combustibles alternos a los convencionales derivados del petroleo y que permita tener una idea clara sobre las tendencias de la investigacion moderna y los desarrollos tecnologicos que puedan ser implementados en el corto plazo. No se pretende abarcar todas las tendencias y desarrollos del mundo actual, sino aquellas que pueden impactar en un plazo relativamente corto, acordes con la vida media de los combustibles convencionales. Sin embargo, la mayor parte de los principios de conversion son aplicables al espectro de materiales carbonaceos o celulosicos los cuales se

  12. Produção de verdade e processos de criminalização: Retificação do registro civil de pessoas trans no judiciário fluminense

    Directory of Open Access Journals (Sweden)

    Maria Luiza Rovaris Cidade

    2017-01-01

    Full Text Available El artículo tiene como objetivo promover la discusión de los procesos de criminali- zación de las experiencias de las personas trans por el análisis de sus procesos de rectificación de registro civil, desde la perspectiva de un cambio de nombre y sexo en el contexto del poder judicial en el estado de Río de Janeiro. Se propone articular las nociones no esencialistas y de auto-atribución de constitución de género, la pers - pectiva de Foucault de la racionalidad moderna política, la noción de individuo y su estatuto jurídico, y la concepción de los procesos de criminalización que se centran en diversas experiencias previstas en la normatividad de cierto pacto social. A partir de un enfoque metodológico para la cartografía, se convoca el discurso del disposi - tivo sobre la transexualidad en el contexto del Poder Judicial de Río de Janeiro para discutir los siguientes puntos: 1 la legalización de la vida a partir de la expansión de los poderes legales en las decisiones de todos los días; 2 identidades trans patoló- gicas y, finalmente, 3 la producción de verdades por expertos en los experimentos de identidad.

  13. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  14. Propostas de Redução da Maioridade Penal: a Juventude Brasileira no Fio da Navalha?

    OpenAIRE

    Vavassori, Mariana Barreto; Toneli, Maria Juracy Filgueiras

    2015-01-01

    Resumo Este trabalho propõe uma reflexão teórica sobre o fenômeno da judicialização da vida, mais especificamente aquele que incide sobre os “adolescentes em conflito com a lei”, a partir das contribuições de Foucault e Derrida. O objetivo é dar visibilidade a alguns dos regimes de verdade sobre “adolescentes em conflito com a lei”, que emergem das/nas propostas de emendas constitucionais (PECs) sobre rebaixamento da idade penal, e seus efeitos de subjetivação. Utilizamos como operador metodo...

  15. Presentación del Libro: Cuasi una Fantasía. Cuentos y Relatos.

    Directory of Open Access Journals (Sweden)

    Efraím Otero Ruiz

    2006-03-01

    - “A decir verdad, no hablo de mi pasado”. Preocupado por mantener la conversación, el periodista repasó en su mente su lista de preguntas. Si no podía preguntarle sobre el pasado y no tenía sentido hacerlo sobre el futuro, sólo quedaba el presente. Y en el presente, estaba aprendiendo, no hay preguntas, solamente el estar...

  16. ¿Existe la verdad científica? Controversia histórica en torno al descubrimiento de Carlos J. Finlay ¿Scientific truth exist? Historic opinions about the discovery of Carlos J. Finlay

    Directory of Open Access Journals (Sweden)

    Rosa Luisa Aguirre del Busto

    2004-12-01

    Full Text Available Las autoras realizan el diseño de una simulación educativa en la asignatura Filosofía y Salud II, que forma parte del plan de estudios, del primer año, de las carreras de medicina, estomatología y enfermería, basada en el descubrimiento de Carlos J Finlay, sobre el agente transmisor de la fiebre Amarilla. Como resultado de una experiencia de trabajo a través de la Cátedra de Estudios CTS + I de la Universidad de la Habana, que propició el desarrollo del “Curso Experimental para la formación de docentes en el enfoque CTS”, realizado en el Campus Virtual de la OEI, se intenta reconstruir la polémica sobre el descubrimiento de Carlos J Finlay, y al mismo tiempo proporcionar herramientas teóricas en torno a la comprensión de la verdad científica como fenómeno social. Utilizando la metodología aprendida en el curso mencionado, se desarrolla el diseño de un “ Estudio de Caso Histórico”, que exige de una fundamentación, una guía didáctica, la contextualización de la controversia, definición de objetivos, identificación de actores y una serie de orientaciones a los alumnos que les permiten desplegar habilidades investigativas y conceptuales, pero que al mismo tiempo despiertan el interés por la vida y la obra del científico camagüeyano. En términos generales se concluye, señalando que es posible utilizar la historia de la medicina como una herramienta imprescindible de la enseñanza curricular del médico. La temática escogida desde la filosofía, sobre la verdad científica, les permite comprender el conocimiento como construcción social, impregnado de intereses y valores, pero de ningún modo arbitrarioThe authors carry out the design of the subject Philosophy and Health II as part of the curriculum for the first year students of the medicine stomatology and nursing, based on Carlos J Finlay' discovery, on the agent that transmits the Yellow fever. As a outcome of an experience in the Health and CTS + I Studies

  17. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika

    1999-11-01

    In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

  18. Voces [en la cabeza]: espacialidad, mediaciones teletecnológicas y las verdades caleidoscópicas en el proceso de Justicia y Paz en Colombia

    Directory of Open Access Journals (Sweden)

    Alejandro Castillejo-Cuéllar

    2013-03-01

    Full Text Available Este texto explora —en el contexto del proceso instaurado por la puesta en marcha de la llamada Ley de Justicia y Paz en Colombia, encargada de administrar “la reincorporación de miembros de grupos armados organizados al margen de la ley”— un espacio legal concreto en el que miembros desmovilizados de las Autodefensas Unidas de Colombia confiesan los actos delictivos que realizaron durante su “pertenencia” al grupo ante un Fiscal Especial de Justicia y Paz. A esta diligencia se le llama técnicamente audiencia de versión libre. Este documento hace parte de una investigación más amplia realizada en diferentes escenarios nacionales sobre lo que llamaría los espacios de la ley, particularmente, en el contexto de la aplicación de leyes transicionales. Así, el documento se concentra, primero, en lo que llamaría una antropología de la ley y la cotidianidad, para mostrar algunos de los elementos que definen la puesta en escena de la versión libre. Segundo, en dicha cotidianidad, pero en el caso específico de seres queridos que usan el proceso de Justicia y Paz para encontrar a sus parientes desaparecidos. Este proceso, donde se vinculan mediaciones auditivas, visuales y orales, produce lo que llamo “verdades caleidoscópicas”, donde fragmentos de historias, lugares y hechos son “unificados” a veces de manera precaria, para formar una imagen del pasado.

  19. Reseña de actividad: Mesa de debate “Políticas de Memoria, Verdad y Justicia: balances y perspectivas”

    OpenAIRE

    Paganini, Mariana; Zubillaga, Paula

    2016-01-01

    El pasado 1° de julio se llevó adelante la mesa de debate “Políticas de Memoria, Verdad y Justicia: balances y perspectivas”, en la sede del Rectorado de la Universidad Nacional de Tres de Febrero (UNTREF). El encuentro estuvo moderado por el Licenciado en Ciencias Políticas Matías Cerezo y contó con la participación del Doctor Daniel Rafecas, titular del Juzgado Criminal y Correccional Federal N° 3 de la Ciudad Autónoma de Buenos Aires, la Doctora en Sociología Elizabeth Jelin y el Doctor en...

  20. APRESENTAR O IRREPRESENTÁVEL: paisagem com bois e vaca amarela

    OpenAIRE

    Paula Glenadel

    2011-01-01

    Aproximar o conto de Guimarães Rosa “Conversa de bois” (Sagarana, 1946) do quadro Vaca amarela (1911), de Franz Marc,pintor expressionista ligado ao movimento Der Blaue Reiter,significa repensar a representação dos animais, forçando os limites do comentário batailliano sobre a “mentira poética da animalidade” até fazer da poesia o lugar de uma verdade ética da hospitalidade com a qual se dá acolhida ao totalmente outro. Essa verdade se manifesta como exigência do impossível, como no dito d...

  1. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

    2013-04-02

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  2. Catalizadores anodicos basados en platino para celdas de combustible de etanol

    Directory of Open Access Journals (Sweden)

    BIBIAN HOYOS

    2007-01-01

    Full Text Available Se estudió el comportamiento electro catalítico de platino puro y aleaciones basadas en él con Ru, Sn, Ir y Os soportados en carbón para la electro oxidación de etanol con el propósito de desarrollar catalizadores anódicos para celdas de combustible directas de etanol. Adicionalmente, se construyeron electrodos porosos y ensambles electrodo-membrana para celdas de combustible poliméricas, en las cuales se probaron los ánodos. La caracterización de los catalizadores se realizó mediante voltametría cíclica, mientras que las pruebas del desempeño de las celdas se realizaron mediante pruebas de polarización corriente-potencial. En general, todas las aleaciones mostraron un menor potencial de inicio de la reacción y mayor actividad catalítica que el platino puro. Sin embargo en la zona de altos sobre potenciales, el platino puro tiene mayor actividad catalítica que las aleaciones. De acuerdo con estos resultados, las aleaciones estudiadas podrían ser útiles en celdas de combustible operando a corrientes moderadas y bajas

  3. Política del testimonio y reconocimiento en las comisiones de la verdad guatemalteca y peruana: En torno a la figura del “indio subversivo”

    Directory of Open Access Journals (Sweden)

    Silvia Rodríguez Maeso

    2012-10-01

    Full Text Available Este texto analiza la política del testimonio en las comisiones de la verdad guatemalteca (Comisión para el Esclarecimiento Histórico – CEH y peruana (Comisión de la Verdad y Reconciliación – CVR, y su reflejo en las narrativas de los respectivos informes finales. El reconocimiento a las víctimas se establece tomando en cuenta las narrativas instauradas para interpretar el proceso de violencia condicionando, de forma decisiva, la producción de ideas y prácticas de ciudadanía centrales en los discursos de ambas comisiones. En estas narrativas las representaciones ideológicas del “indio subversivo” afectan directamente al estatus, como tales, de las principales víctimas/afectados por el conflicto (las poblaciones campesino‑indígenas y al lugar que la desigualdad étnico‑racial y en particular el racismo, adquieren en la interpretación que las comisiones ofrecen de los conflictos armados. Así, el trabajo de ambas comisiones y las discusiones académicas que lo antecedieron revelan la compleja relación – con profundas raíces históricas – entre indianidad y política.

  4. Sobre a objetividade na relação sujeito-objeto no plano da imagem ou da esfera instrumental/organizacional: um ponto de vista para a pesquisa na enfermagem Sobre la objetividad en la relación sujeto - objeto en el plan de la imagen o de la esfera instrumental/organizacional: un punto de vista para la investigación en la enfermería About the objectivity in the subject-object relationship in the image’s plan or in the instrumental/organizational scope: a point of view for the nursing research

    Directory of Open Access Journals (Sweden)

    Vilma de Carvalho

    2008-06-01

    Full Text Available Discussão sobre a objetividade na relação sujeito-objeto - âmbito do fenômeno do conhecimento e pesquisas/estudos de enfermagem. A abordagem teórico-filosófica incide sobre a esfera intermediária - instrumental/organizacional - relativamente a possíveis verdades aproximadas. Essa esfera entendida como esfera da "imagem" ou espaço formal ( locus virtual? de transferência de caracteres da realidade objetiva. A análise de natureza gnoseológico-epistemológica, sem pretensões aprofundadas, salvo o alcance da compreensão para estudos ou buscas investigativas em plano de núcleos de pesquisa na enfermagem. A autora assume a crítica em favor do domínio de conceitos e categorias do conhecer e relativamente à enfermagem enquanto "ciência-em-vias-de-se-fazer". Aponta para o risco de confundir-se, de um lado, o plano pragmático/ assistencial (trabalho e operações práticas e, de outro, o plano gnoseológico/epistemológico (trabalho teórico-acadêmico de buscas de verdades aproximadas. E apresenta argumentos/justificavas lógicas para as distinções entre interesses do sujeito pesquisador (plano da Subjetividade e outros apropriados à construção científica (plano da Objetividade.Discusión sobre la objetividad en la relación sujeto-objeto, ámbito del fenómeno del conocimiento / interés de la investigación/ estudios de enfermería. El abordaje de efecto teórico-filosófico incide sobre la esfera intermedia - instrumental/organizacional - relacionada con la formalización de posibles verdades aproximadas. Esa esfera entendida como esfera de la "imagen" o espacio formal de transferencia de determinaciones o caracteres del real objetivo. El análisis es de naturaleza gnoseológicoepistemológica, sin pretensiones profundas, salvo el alcance de comprensión para estudios o indagaciones en el plano de núcleos de investigación en enfermería. La autora hace la critica en favor de conceptos y categorías del conocer y en lo que

  5. La orientación por el síntoma

    Directory of Open Access Journals (Sweden)

    Kelly Jobana Dávila Córdoba

    2016-01-01

    Full Text Available Las discusiones actuales sobre el papel del síntoma en las posiciones subjetivas contemporáneas interpelan constantemente a los analistas sobre su funcionamiento y el de las formas de padecimiento que en él subyacen. Resulta interesante retomar algunos planteamientos freudianos y lacanianos al respecto, en aras de circunscribir los fundamentos del síntoma a la verdad que pone en juego y su forma de implicancia en los lazos sociales. Destacando su lugar esencial en el proceso analítico, se sostiene su función de orientar la práctica analítica, práctica que se guía por la recuperación de goce inherente al síntoma y por la verdad que este evidencia.

  6. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.

    2017-03-28

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  7. Analysis regarding steam generator furnace's incident heat, temperature and composition of combustion gases; Analisis de calor incidente, temperatura y composicion de gases de combustion en hornos de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    In order to obtain more precise evaluations of the combustion process in the furnace of a steam generator a suction pyrometer has been integrated to measure the temperature of the combustion gases; an ellipsoidal radiometer to measure the incident heat by thermal radiation in the water walls; a water cooled probe to determine the particle concentration, as well as a water cooled probe to determine the composition of the combustion gases present. This document clarifies the form of use of these instruments and their engineering specifications, simultaneously presenting an analysis that considers, unlike others, the internal conditions of the furnace to obtain a more precise evaluation of the efficiency that the combustion process presents and bases for the taking of preventive actions in specific zones of the furnace. Thus, the present work exhibits instruments and techniques of analysis to study the phenomena occurring within a steam generator. [Spanish] Con el fin de obtener evaluaciones mas precisas del proceso de combustion en el horno de un generador de vapor, se ha integrado un pirometro de succion para medir la temperatura de los gases de combustion; un radiometro elipsoidal para medir el calor incidente por radiacion termica en las paredes del agua; una sonda enfriada con agua para determinar la concentracion de particulas, asi como una sonda refrigerada con agua para determinar la composicion de los gases de combustion presentes. Este documento aclara la forma de uso de estos instrumentos y sus especificaciones tecnicas, a la vez que presenta un analisis que considera, a diferencia de otros, las condiciones internas del horno para obtener una evaluacion mas precisa sobre la eficiencia del proceso de combustion y bases para la toma de acciones preventivas en zonas especificas del horno. Asi, el presente trabajo exhibe instrumentos y tecnicas de analisis para estudiar los fenomenos que ocurren dentro de un generador de vapor.

  8. IEA combustion agreement : a collaborative task on alternative fuels in combustion

    International Nuclear Information System (INIS)

    Larmi, M.

    2009-01-01

    The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

  9. Internal combustion engine using premixed combustion of stratified charges

    Science.gov (United States)

    Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  10. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

    2017-01-01

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

  11. Fuel and combustion stratification study of Partially Premixed Combustion

    OpenAIRE

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

  12. Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

    Energy Technology Data Exchange (ETDEWEB)

    Epinat, G. [APAVE Lyonnaise, 69 (France)

    1996-12-31

    After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

  13. Combustion stratification for naphtha from CI combustion to PPC

    NARCIS (Netherlands)

    Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

    2017-01-01

    This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

  14. Low NOx combustion technologies for high-temperature natural gas combustion

    International Nuclear Information System (INIS)

    Flamme, Michael

    1999-01-01

    Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

  15. Combustion instability control in the model of combustion chamber

    International Nuclear Information System (INIS)

    Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

    2013-01-01

    An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

  16. Degradação catalítica de polietileno de alta densidade sobre a zeólita HZSM

    OpenAIRE

    Lima, Stevie Hallen

    2009-01-01

    Nos últimos anos tem-se falado muito sobre o meio ambiente e sobre o lixo plástico produzido e descartado. Nas últimas décadas, o crescente desenvolvimento de pesquisas com o intuito de obter combustíveis a partir de material plástico, via degradação catalítica, tem-se tornado uma busca muito atrativa, já que esses rejeitos são descartados aos milhões em todo mundo. Esses materiais levam muito tempo para se degradar por meios ditos naturais e sua incineração não tem se demonstrado uma alte...

  17. Rotary combustion device

    NARCIS (Netherlands)

    2008-01-01

    Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

  18. CONCEPTOS SOBRE LA FORMACIÓN DEL HOMBRE

    Directory of Open Access Journals (Sweden)

    Fernando Sánchez Torres

    1981-10-01

    disfrutar y a aprovechar el ocio. Y cuando digo "ocio" no lo digo en el sentido de la inactividad condenable, sino en el sentido clásico: un estado de alma, un estado contemplativo.
    Nos recuerda Pedro Laín Entralgo en su docto ensayo sobre "ocio y trabajo" que los griegos decían al ocio skhole. palabra de la cual deriva la latina schola. escuela. En su concepto, ocio es uno de los fundamentos más profundos y venerables de la cultura occidental. "Ocio -dice- es la actividad no trabajosa ni utilitaria en que el alma humana logra su más alta y específica nobleza".

    La historia de la especulación con las ideas, el ocio, empieza en el Occidente, seis siglos antes de Jesucristo, y se inicia precisamente en Grecia donde el gusto por la filosofía, el amor por la verdad, era innato en sus pobladores.
    La primera escuela de filosofía se estableció en Mileto, ciudad de la antigua Jonia (colonia griega en Asia Menor, y el más conocido de los filósofos milesios fue TALES.
    Recordemos que los filósofos milesios fueron monistas, es decir, que para ellos la última realidad de las cosas era la unidad (monos = único, singular, en contraposición a los pluralistas...

  19. Las víctimas en el proceso de Justicia y paz. Carácter simbólico de la verdad, la justicia y la reparación en la transición hacia la convivencia

    Directory of Open Access Journals (Sweden)

    Hernando Barreto Ardila

    2009-12-01

    Full Text Available En el curso de los procesos de Justicia y Paz juega papel preponderante el carácter simbólico del derecho penal, motivo por el cual es preciso implementar sistemas selectivos para investigar y sancionar a los responsables de mayor importancia y respecto de las conductas más graves, disponer urgentemente la reparación administrativa de las víctimas y crear espacios extrajudiciales para reconstruir la verdad, procederes sin los cuales no hay lugar a la justicia transicional complementada por la justicia restaurativa, sin olvido de unos mínimos de justicia retributiva. No se debe adelantar investigaciones individuales como si se tratara de asuntos inconexos, sino tramitar macroprocesos, pues se trata de la reconstrucción judicial, no de una verdad episódica, sino de una situación con un amplio desarrollo extendido en el tiempo y el espacio.

  20. Uma análise sobre transmasculinidades presentes numa série da mídia televisiva

    Directory of Open Access Journals (Sweden)

    Thais Geraldo Oliveira de Aguiar

    2018-02-01

    Full Text Available Neste trabalho temos como objetivo analisar alguns significados sobre transmasculinidades presentes em dois episódios da série Liberdade de Gênero, exibida no canal de televisão brasileiro por assinatura GNT. Entendemos esta série como um potente artefato cultural para reflexão acerca das identidades trans, nela são apresentadas algumas histórias de pessoas que não se identificam com o gênero designado para elas ao nascerem, negando qualquer determinismo biológico. O preconceito, a exclusão social, a pressão religiosa e familiar que esses sujeitos vivenciam, no caso dos entrevistados, não venceram o desejo de ser quem sentiam ser. Nossos estudos têm como base os Estudos Culturais, na sua vertente pós-estruturalista, destacando o efeito das mídias na produção dos corpos e das sexualidades e também como produtora de saberes e conhecimentos, entendendo que os discursos veiculados pela mídia acionam efeitos de verdade e que essa proliferação de discursos vem atuando na produção dos sujeitos. A metodologia da pesquisa consiste na análise cultural, entendendo que esse tipo de análise é potente para pensar o quanto as pedagogias exercidas por estes artefatos são produtivas na constituição dos sujeitos e como vêm produzindo e reproduzindo significados acerca da transgeneridade, em específico sobre os homens trans.

  1. Combustion physics

    Science.gov (United States)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  2. El biodiesel de aceite de higuerilla como combustible alternativo para motores diesel

    OpenAIRE

    ALIRIO BENAVIDES; PEDRO BENJUMEA; VESELINA PASHOVA

    2007-01-01

    En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróle...

  3. EL BIODIESEL DE ACEITE DE HIGUERILLA COMO COMBUSTIBLE ALTERNATIVO PARA MOTORES DIESEL

    OpenAIRE

    BENAVIDES, ALIRIO; BENJUMEA, PEDRO; PASHOVA, VESELINA

    2007-01-01

    En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróle...

  4. El rostro bifronte de la ciencia: notas sobre la relación entre ciencia e ideología en Habermas y Althusser

    Directory of Open Access Journals (Sweden)

    Lisandro Alejo Martinez

    2015-06-01

    Full Text Available El presente trabajo aborda la relación entre ciencia e ideología a través de la revisión crítica de las perspectivas de Jürgen Habermas y Louis Althusser. Nos interesa indagar sobre el carácter difuso de los límites entre ambos conceptos en el contexto del capitalismo tardío, de donde surge la pregunta acerca de si es posible pensar la ciencia como ideología. Si fuera así, ¿cuáles son los rasgos de la ideología y de la ciencia orientados a trascender la oposición entre verdad y falsedad? Para responder a dichos interrogantes, se propone llevar a cabo una lectura doble: leer a Habermas con Althusser y a Althusser con Habermas. En principio, se trata de leer a Habermas desde Althusser, con el propósito de analizar las implicancias procedentes de su crítica de las ideologías a través de un criterio normativo, cuyo punto de llegada es la comunidad de comunicación libre de dominio. Luego, en un segundo momento, se lleva a cabo una lectura de Althusser desde Habermas, con el objetivo de formularle a Althusser los interrogantes habermasianos sobre la función ideológica de la ciencia en el capitalismo tardío.

  5. Sentidos de la sexualidad y la adolescencia en mujeres adolescentes entre 13-16 años, víctimas de explotación sexual comercial

    OpenAIRE

    Cajas Vargas, Pamela Liseth; Egas Rosero, Wendy Patricia

    2012-01-01

    La construcción histórica social de la adolescencia, la ha establecido como una categoría etaria que define condiciones de vulnerabilidad y malestar en cada una de sus dimensiones, legitimada en discursos y espacios que responden a la necesidad de mantener un control envolvente sobre este grupo poblacional, insertando elementos simbólicos e imaginarios instauradas como verdades pluralizadas, sobre su realidad invalidando toda producción discursiva particular que los evidenci...

  6. Discursos sobre juventude e práticas psicológicas: a produção dos modos de ser jovem. Brasil

    Directory of Open Access Journals (Sweden)

    Zuleika Köhler Gonzales

    2008-01-01

    Full Text Available La persona joven ha sido centro de atención por parte de las instituciones sociales, tanto públicas como privadas. En los discursos de la sociedad sobre esta población, el joven o la joven se asocia, actualmente, a la idea de inserción en los procesos sociales. En el campo académico, se percibe una importante producción de investigaciones y de conocimiento acerca de la juventud. En las producciones del conocimiento sobre la juventud circula un discurso de "preocupación" con relación a los jóvenes y a las jóvenes, en cuanto a su integración en el orden social, económico y familiar. En este artículo, se hace referencia a las concepciones de juventud que fueron legitimadas en diferentes momentos sociales y se pretende comprender cómo se ha visibilizado un determinado discurso sobre esta categoría, generalmente asociado a la noción de problema. En el proceso, se busca discutir las implicaciones de este discurso en las prácticas psicológicas e indagar cómo los jóvenes y las jóvenes están siendo afectados y afectadas por determinadas prácticas sociales contemporáneas, generando diversos modos de subjetivación, que al mismo tiempo son pensados, fomentados y resignificados en relaciones de poder y verdad, sustentadas por saberes como el psicológico. También se pretende evidenciar cómo esos sujetos han sido intervenidos por el mercado capitalista como consumidores y consumidoras en potencia.

  7. Some Factors Affecting Combustion in an Internal-Combustion Engine

    Science.gov (United States)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

  8. Reduced NOX combustion method

    International Nuclear Information System (INIS)

    Delano, M.A.

    1991-01-01

    This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

  9. Regulation on power efficiency in the automobile; Regulacion sobre eficiencia energetica en el automovil

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado Susano, Armando; Romero de Vivar Uvaldo, Pascual [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    2001-07-01

    In this article it is presented a brief analysis of one of the regulations on the yield of fuel consumption of the light vehicles that promoted substantial changes in the Mexican automotive industry, the decree denominated PREMCE (Average of minimum fuel yield by company), as well as some international experiences relative to the subject. It is also indicated the evolution, in the last years, of the average yields of fuel consumption (Km/L) in Mexico in the new automobiles and the more important technological factors that affect their energy efficiency. [Spanish] En este articulo se presenta un breve analisis de una de las regulaciones sobre el rendimiento de consumo de combustible de los vehiculos ligeros que promovio cambios sustanciales en la industria automotriz mexicana, el decreto denominado Premce (Promedio de rendimiento minimo de combustible por empresa), asi como algunas experiencias internacionales relativas al tema. Se senala tambien la evolucion, en los ultimos anos, de los rendimientos promedio de consumo de combustible (Km/L) en Mexico en los automoviles nuevos y los factores tecnologicos mas importantes que influyen en su eficiencia energetica.

  10. Michel Foucault e a construção discursiva do corpo do sujeito moderno e sua relação com a psicologia Michel Foucault y la construcción discursiva del cuerpo de lo sujeto moderno y su relación con la psicologia Michel Foucault and the discursive construction of modern subject's body and their relation with psychology

    Directory of Open Access Journals (Sweden)

    Fernando de Almeida Silveira

    2008-12-01

    Full Text Available Michel Foucault investiga "a história das relações que o pensamento mantém com a verdade" e como se estabelece a correlação entre pensamento e verdade, tendo o enunciado do corpo como elemento discursivo fundamental na constituição dos jogos de verdades sobre o sujeito moderno. Através da leitura da bibliografia desse autor, de comentaristas e de outros filósofos modernos, esta pesquisa estuda a questão do corpo na fase arqueológica foucaultiana, principalmente no livro As Palavras e As Coisas, destacando as formações discursivas do corpo, da vida e do homem em seus efeitos subjetivadores, com especial referência à constituição discursiva do sujeito psicológico. Verificou-se que Foucault desnaturaliza o corpo, apresentando-o como conceito-chave (ou grade de especificação na produção de discursos sobre o homem moderno, o que nos permite também compreender a psiqué não como emanação ou essência metafísica do corpo, mas como instrumento discursivo, singularmente emergente na história do pensamento moderno.Michel Foucault investiga "la historia de las relaciones que el pensamiento mantiene con la verdad" y como la correlación entre el pensamiento y la verdad es establecida, al traer el cuerpo como elemento discursivo fundamental en los juegos de verdades sobre la constitución del sujeto moderno. A través de la lectura de la bibliografía de este autor, comentaristas y otros filósofos, la investigación estudia la cuestión del cuerpo en la fase de Foucault arqueológica, principalmente en "Las Palabras y las Cosas", destacando las formaciones discursivas del cuerpo, de la vida y del hombre en sus efectos sujetivadores, a la constitución del sujeto psicológico. Se comprobó que Foucault desnaturaliza el cuerpo, presentándolo como concepto-clave en la producción de discursos sobre el hombre moderno. Lo que nos permite comprender también la psiqué, no como emanación o esencia metafísica del cuerpo, sino como

  11. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    Science.gov (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  12. Idealtipos y modelación: bases epistémicas contra “verdades universalistas” sobre el calentamiento climático

    Directory of Open Access Journals (Sweden)

    Antonio Arellano-Hernández

    2015-01-01

    Full Text Available Resumen: En este texto nos proponemos analizar las posibilidades epistémicas de los idealtipos para emplear su significación en la práctica de modelación numérica climática; sostendremos que los conceptos científicos y particularmente los modelos y aún más los modelos climáticos deben tener el estatuto epistémico de idealtipos. El plan consiste en traducir el tema metodológico del idealtipo con el de la modelación numérica del clima para intentar avanzar una propuesta que depotencie las pretensiones universalistas de las acuñaciones cognoscitivas de la ciencia contemporánea y en particular de la modelación climática, para que sea factible establecer un mecanismo de autocontrol científico que sintetice explicaciones subjetivas y procesos de validación objetiva. A partir de estas reflexiones, consideramos que sería adecuado que los modeladores y sus instituciones asumieran la modelación climática, guardando un espacio de autocontrol científico que permita aperturas epistemológicas en lugar de imposibles tareas nomológicas concluyentes sobre el calentamiento climático.

  13. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Pancerella; L. A. Rahn; C. Yang

    2000-02-01

    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  14. Efecto sobre la reacción de oxígeno de la forma y la microestructura del contacto electrodo-electrolito de electrodos a difusión interna en Celdas de Combustible de Óxido Sólido (SOFC

    Directory of Open Access Journals (Sweden)

    Jiménez, R.

    1999-12-01

    Full Text Available In this work we have studied the elemental electrode shape and electrode - electrolyte contact microstructure influence of Internal diffusion (ID gas electrode in solid oxide fuel cells (SOFC. First the influence over the electrolyte effective resistance is studied. Then the influence of the shape of the elemental contact grain of ID electrode is also studied. Finally the influence of the electrode - electrolyte contact microstructure in the electrode response for a pure diffuse control is modelled. From the obtained results, conclusions on the contact microstructure and electrode shape influence over the oxygen reaction of this kind of gas electrodes are commented.

    En este trabajo, se estudia la influencia de la forma del electrodo elemental y la microestructura del contacto electrodo-electrolito, del electrodo de gas a difusión interna en celdas de combustible de óxido sólido (SOFC. Se determina la influencia de la microestructura del contacto electrodo electrolito sobre la resistencia efectiva del electrolito, la influencia de la forma del contacto de un grano elemental de un electrodo poroso suponiendo que sea aproximadamente una semiesfera sobre la reacción del electrodo y finalmente la influencia de la microestructura del contacto electrodo - electrolito en la respuesta a un control difusivo puro del electrodo. De los resultados obtenidos se pueden extraer conclusiones sobre la influencia de la microestructura del contacto y forma del electrodo en la reacción de oxígeno en este tipo de electrodos de gas.

  15. Amor: ¿Verdad o Consumo?

    Directory of Open Access Journals (Sweden)

    Nieves Salobral Martín

    2015-02-01

    Full Text Available La noción cristiana del amor establecida por Agustin de Hipona se conserva en nuestro imaginario social. Distingue el amor como un movimiento de anhelo hacia el objeto deseado, que culmina en la fusión con lo amado, así la felicidad es alcanzada gracias a esta unicidad. Dos modelos amorosos se consideran en su análisis cáritas y cupiditas, el primero como verdadero y el segundo como erróneo. Una de las modificaciones corporales e inclinaciones más elaboradas es el orden simbólico de la dominación masculina; es también un dispositivo esencial para la socialización amorosa. Este procedimiento disciplinario sobre los cuerpos les predispone a una construcción ética sexualmente diferenciada: la ética de los cuidados y la responsabilidad y la ética de la justicia y los derechos. El capitalismo expone al amor como objeto de consumo para convertirse en fetiche del mercado. Y ambas identidades morales deben alcanzar el amor para cumplir con el mandato ético.

  16. New class of combustion processes

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Borovinskaya, I.P.

    1975-01-01

    A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

  17. Experimental validation for combustion analysis of GOTHIC code in 2-dimensional combustion chamber

    International Nuclear Information System (INIS)

    Lee, J. W.; Yang, S. Y.; Park, K. C.; Jung, S. H.

    2002-01-01

    In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. The experimental chamber has about 24 liter free volume (1x0.024x1 m 3 ) and 2-dimensional rectangular shape. The test were preformed with 10% hydrogen/air gas mixture and conducted with combination of two igniter positions (top center, top corner) and two boundary conditions (bottom full open, bottom right half open). Using the lumped parameter and mechanistic combustion model in GOTHIC code, the SNU experiments were simulated under the same conditions. The GOTHIC code prediction of the hydrogen combustion phenomena did not compare well with the experimental results. In case of lumped parameter simulation, the combustion time was predicted appropriately. But any other local information related combustion phenomena could not be obtained. In case of mechanistic combustion analysis, the physical combustion phenomena of gas mixture were not matched experimental ones. In boundary open cases, the GOTHIC predicted very long combustion time and the flame front propagation could not simulate appropriately. Though GOTHIC showed flame propagation phenomenon in adiabatic calculation, the induction time of combustion was still very long compare with experimental results. Also, it was found that the combustion model of GOTHIC code had some weak points in low concentration of hydrogen combustion simulation

  18. EFECTO DE LA COMPOSICIÓN DEL GAS DE REFINERÍA SOBRE LAS CARACTERÍSTICAS DEL PROCESO DE COMBUSTIÓN

    OpenAIRE

    Cala, O. M.; Meriño, L.; Kafarov, V.; Saavedra, J.

    2013-01-01

    En este artículo de investigación científica se analiza el efecto del cambio de la composición del gas combustible (Gas de Refinería (GR) por Gas Natural (GN)) sobre las características del proceso combustión en hornos de la industria de refinación del petróleo; se evaluó el poder calorífico, el índice de Wobbe (IW) y exceso de oxígeno, para mezclas combustibles de composición variable. Mediante simulación computacional del proceso de combustión se calculó la temperatura adiabática de llama, ...

  19. MYTHS AND LEGENDS OF THE GAMES ROLE MITOS Y LEYENDAS SOBRE LOS JUEGOS DE ROL

    Directory of Open Access Journals (Sweden)

    Rocío Tizón

    2010-11-01

    Full Text Available p { margin-bottom: 0.21cm; } Roleplaying Games were born in the 70´s in the United States, created by Gary Gigax and Dave Arneson, both parents of the now famous game Dungeons & Dragons. However, this game had few years of calm, because in its native country it was found guilty of promoting the suicide of several teenagers who were Dungeons & Dragons players. The lies of the information concerned and the prejudices of the news about these roleplaying games caused that some people became interested in the topic, analyzing those myths and checking the truth of these rumors. One of these scholars was William Watson, creator of the website called The Inquirer, which is dedicated to dismantle these and other prejudices about roleplaying games.Los juegos de rol aparecen en la década de los años 70 en Estados Unidos, creados por Gary Gigax y Dave Arneson, padres del ya famoso Dragones & Mazmorras. No obstante, fueron pocos los años de tranquilidad, ya que en su país natal se le consideró culpable de promover el suicidio de varios adolescentes que habían sido jugadores de Dragones & Mazmorras. Los engaños de la información y los prejuicios de las noticias sobre estos juegos de rol provocaron que varias personas se interesaran por este fenómeno, analizando dichos mitos y comprobando la verdad de estos rumores. Uno de estos estudiosos fue William Watson, creador de la página web The Inquirer, en la que se dedica a desmontar estos y otros tópicos sobre juegos de rol.

  20. Preliminary assessment of combustion modes for internal combustion wave rotors

    Science.gov (United States)

    Nalim, M. Razi

    1995-01-01

    Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

  1. El PRT-La Verdad entre los trabajadores de la carne de Berisso: La agrupación El Activista de la Carne y la Lista Gris [1967-1972

    Directory of Open Access Journals (Sweden)

    Christian Carlos Hernán Castillo

    2011-10-01

    Full Text Available This article is part of a research about the working class and students struggles and the strategies of the left parties in La Plata city and Gran La Plata between 1966 and 1973. This work is focused on the study of the political activity of the PRT-La Verdad during this period. At the beginning of 1968 the Partido Revolucionario de los Trabajadores -PRT split in two fractions. The fraction led by Nahuel Moreno -named PRT-La Verdad [PRT- The Truth]- was the largest of the two in La Plata y Gran La Plata. In this area the PRT had many members among the students and in the workers movement. This article studies the political activity of the PRT, and the PRT-LV after the split- in the Sindicato de Obreros y Empleados de la Industria de la Carne y Afines de Berisso [Meat Processing Plants Workers Union], between 1967 and 1972 at the Swift and Armour meat processing plants. During the period analyzed in the article, the members and supporters of the PRT-LV were organized in a rank and file union group named El Activista de la Carne - Lista Gris [The Activist-Gray List]. The sources of this research are the bulletins and leaflets edited by El Activista de la Carne. We also consulted the files of DIPBA as well as the bibliography on the subject

  2. La experiencia moral: una ética sin verdades absolutas

    Directory of Open Access Journals (Sweden)

    Barroso Fernández, Óscar

    2016-08-01

    Full Text Available The aim of this paper is to reconstruct the Zubirian approach to the moral kind of knowledge. It is, therefore, necessary to examine Zubiri’s writings on moral anthropology from the 1950s, starting from the most complete one, namely Sentient intelligence. If there is the possibility of contemplating a moral knowledge, we should discover its reference system and determine how it is built upon the contents given in the primordial impression of reality, mediated by the logos and its particular form of knowledge, with all the outlines, experiences and truths. On this basis, we prove that is impossible to found morality in a universal and absolute sense. In any case, the possibility of a universal sphere should not be conceived as something a priori, but rather as a regulative ideal of moral experience, that is, something that reason always tends towards, but never reaches.En este trabajo se pretende reconstruir la propuesta zubiriana de un saber de tipo moral. Este objetivo exige mirar los textos de antropología moral escritos por Zubiri en los años cincuenta desde su obra más acabada: Inteligencia sentiente. Si efectivamente se puede hablar de un saber moral, habrá que descubrir cuál es su sistema de referencia, constituido por determinados contenidos dados en impresión primordial de realidad y mediados por el logos, y su forma de conocimiento, con sus esbozos, experiencias y verdades. A partir de aquí, el autor muestra que no es posible, desde la filosofía de Zubiri, proponer una fundamentación de la moral en sentido universal y absoluto. En todo caso, la posibilidad de un ámbito universal de moralidad no puede ser entendida como algo dado a priori, sino más bien como un ideal regulativo de la experiencia moral, algo a lo que la razón apunta pero nunca llega.

  3. Historia, memoria y narrativa en Vivir para Contarla de Gabriel García Márquez

    Directory of Open Access Journals (Sweden)

    Iván Jiménez

    2006-01-01

    Full Text Available A partir de una lectura de las memorias de García Márquez sobreel Bogotazo, realizamos una defensa de la narrativa como espaciopropicio para la construcción de verdades sobre los hechos reales.Nuestro análisis se organiza en tres ejes temáticos: los eleme

  4. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  5. A predictive model of natural gas mixture combustion in internal combustion engines

    Directory of Open Access Journals (Sweden)

    Henry Espinoza

    2007-05-01

    Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

  6. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  7. Sobre dois conceitos de Foucault

    Directory of Open Access Journals (Sweden)

    Sirio Possenti

    2007-11-01

    Full Text Available 0 objetivo deste trabalho é defender uma certa leitura de Foucault, em especial no que se refere aos conceitos de saber e de verdade, frequentemente tomados em sentido corrente. A razão é que, se Foucault for lido assim, algumas de suas hipóteses perdem completamente seu vigor e sua produtividade, tomando-se inúteis para perceber — e este é um de seus propósitos — a especificidade do funcionamento de certos discursos, seja no que se refere a sua forma de produção quanto no que se refere as relações entre os discursos.

  8. HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

    2004-07-01

    This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

  9. SECCIÓN ABIERTA - 5. VERDAD E INCERTIDUMBRE: UNA MIRADA DESDE LA PERSPECTIVA SOCIOPRÁXICA // TRUTH AND UNCERTAINTY: A VIEW FROM THE SOCIOPRAXIC PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Manuel Montañés Serrano

    2012-06-01

    Full Text Available Descartada la magia y la teología como fuente de conocimiento, a largo de la Historia, el dilema de la verdad versus incertidumbre del conocimiento social, se ha planteado en tres frentes: Relación del investigador con el objeto investigado; relación del investigador con el objeto/sujeto investigado; y relación entre realidades universales y particulares. A su vez, cada una de estas relaciones se ha concretado en diversas concepciones dicotómicas. En este artículo, se dará cuenta de las mismas, así como de las correspondientes propuestas superadoras construidas desde una perspectiva sociopráxica.

  10. Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

    1990-10-01

    Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

  11. Análisis bibliométrico de las tesis doctorales sobre Ética de los Medios de Comunicación presentadas en España (1979-2013

    Directory of Open Access Journals (Sweden)

    Jesús Díaz Campo

    2015-05-01

    Full Text Available Esta investigación analiza las tesis doctorales sobre Ética de los Medios de Comunicación defendidas en las universidades españolas en el periodo 1979-2013. Para localizar las tesis se ha utilizado principalmente la base de datos Teseo, pero también se han consultado otras fuentes. El número de tesis analizadas en el periodo estudiado asciende a 75 títulos. La metodología empleada es el análisis bibliométrico. Los resultados describen la producción según quinquenios, idioma de la tesis, sexo del doctorado, universidades y facultades de lectura, tribunales y temática estudiada. Asimismo, los resultados muestran un incremento constante del número de tesis y que la universidad más productiva es la Complutense. Por categorías temáticas, los trabajos más numerosos son los que abordan cuestiones relacionadas con la verdad, la responsabilidad y la autorregulación.

  12. Uncertainties in hydrogen combustion

    International Nuclear Information System (INIS)

    Stamps, D.W.; Wong, C.C.; Nelson, L.S.

    1988-01-01

    Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

  13. The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

    Science.gov (United States)

    Firmansyah; Aziz, A. R. A.; Heikal, M. R.

    2015-12-01

    The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

  14. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

    Science.gov (United States)

    Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

    2016-05-01

    Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Reflexiones sobre la lectura y la escritura en el quehacer universitario

    Directory of Open Access Journals (Sweden)

    Clemencia Montana de Barragan

    1994-10-01

    Full Text Available Para lograr una educación de calidad se requiere que la formación de los docentes incluya no solamente aspectos profesionales sino también pedagógicos y, en verdad, estos últimos no son siempre los mejores. Los profesores universitarios son ante todo expertos en una disciplina o en algunas áreas del conocimiento.

  16. Fuel and combustion stratification study of Partially Premixed Combustion

    NARCIS (Netherlands)

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

  17. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  18. Effect of Variant End of Injection Period on Combustion Process of Biodiesel Combustion

    Directory of Open Access Journals (Sweden)

    Khalid Amir

    2016-01-01

    Full Text Available Biodiesel is an alternative fuel as a replacement to the standard diesel fuel in combustion diesel engine. The biodiesel fuel has a significantly influences throughout the combustion process and exhaust emission. The purpose of this research is to investigate the combustion process behavior during the End of Injection (EOI period and operates under variant conditions using Rapid Compression Machine (RCM. Experimental of RCM is used to simulate a combustion process and combustion characteristics of diesel engine combustion. Three types of biodiesel blend which are B5, B10 and B15 were tested at several injection pressures of 80 MPa, 90 MPa and 130 MPa under different ambient temperatures, 750 K to 1100 K. The results of this study showed that the ignition delay slightly reduced with increasing the content of biodiesel blends from B5, B10 and B15 and became more shorten as the injection pressure been enhanced. As the injection pressure increased, the behavior of combustion pressure at end of injection is reduced, radically increased the NOX emission. It is noted that the process of combustion at the end of injection increased as the ambient temperature is rising. In fact, higher initial ambient temperature improved the fuel atomization and mixing process. Under the biodiesel combustion with higher ambient temperature condition, the exhaust emission of CO, O2, and HC became less but increased in NOX emission. Besides, increased in blends of biodiesel ratio are found to enhance the combustion process, resulted a decreased in HC emissions.

  19. Homosexualidad y homosexuales en Cuba: la verdad oculta

    OpenAIRE

    Robledo Díaz, Luis

    1998-01-01

    La homofobia en Cuba se ha venido construyendo sobre esta base y ha hecho suponer que el homosexual es inevitablemente un vicioso, inmoral y pervertidor de niños. El homosexual es extirpado del concepto de nación y luego de 1959 ya no solamente se llega a considerar como tal sino que bajo el juego de identidades de nación/patria/revolución/socialismo se le suma el de ser antipatriota, contrarrevolucionario y desviado política e ideológicamente. Al enlazarse la entereza física con una eticidad...

  20. Jet plume injection and combustion system for internal combustion engines

    Science.gov (United States)

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

    1993-01-01

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  1. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  2. Combustion, detonation, shock waves. Proceedings of the Zel'dovich memorial - International conference on combustion. Volume 1

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Frolov, S.M.

    1995-01-01

    This book contains lectures by the experts in various fields of modern research in combustion, detonation and shock waves, presented at the Zel'dovich memorial - International conference on combustion dedicated to the 80-th birthday of academician Ya.B. Zel'dovich. There are eight chapters discussing the state-of-the-art in combustion kinetics, ignition and steady-state flame propagation, diffusion and heterogeneous combustion, turbulent combustion, unsteady combustion, detonation, combustion and detonation analogies, intense shock waves and extreme states of matter [ru

  3. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-08-17

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  4. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-01-01

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  5. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  6. Combustion Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  7. Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

  8. Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

    2005-03-01

    This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

  9. Twenty-fifth symposium (international) on combustion

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

  10. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  11. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

  12. Decrease of noxious emissions in the residual fuel oil combustion; Disminucion de emisiones nocivas en la combustion de aceite combustible residual

    Energy Technology Data Exchange (ETDEWEB)

    Mandoki W, Jorge [Econergia S. de R. L. de C. V. Mexico, D. F. (Mexico)

    1994-12-31

    The residual fuel oil combustion emits noxious substances such as carbonaceous particulate, nitrogen oxides, and sulfur trioxide at unacceptable levels. Water emulsified in the fuel substantially reduces such emissions, achieving besides, in most of the cases, a net saving in the fuel consumption. The beneficial effects are shown in burning the residual fuel oil as a water emulsion, as well as the method to produce an adequate emulsion. The emulsified fuel technology offers a low cost option to reduce air pollution. The fuel oil quality has been declining during the last decades due to: 1. Increase in the production of crude heavy oils, generally with higher content of asphaltens and sulfur. 2. Less availability of vacuum distillation residues due to its conversion into greater value products. 3. More intensive conversion processes such as catalytic cracking, visbreaking, etc. that increase the asphaltenes concentration in the bottoms, causing instability problems. 4. The increase in the vanadium and other metals content as the concentration of asphaltenes increases. The use of emulsified fuel oil provides an efficient and economical method to substantially reduce the noxious emissions to the atmosphere. The emulsion contains water particles in a diameter between 2 and 20 microns, uniformly distributed in the fuel oil, generally in a proportion generally of 5 to 10%; besides, it contains a tensioactive agent to assure a stable emulsion capable of withstanding the shearing forces of the pumping and distribution systems. When the atomized oil drops get into the combustion chamber, the emulsified water flashes into high pressure steam, originating a violent secondary atomization. The effect of this secondary atomization is the rupture of the oil drops of various hundred microns, producing drops of 5 to 15 microns in diameter. Since the necessary time for combustion is an exponential function of the drop diameter, a very substantial improvement in the combustion is

  13. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  14. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    Science.gov (United States)

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  15. Fuel Combustion Laboratory | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

  16. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  17. El biodiesel de aceite de higuerilla como combustible alternativo para motores diesel

    Directory of Open Access Journals (Sweden)

    ALIRIO BENAVIDES

    2007-01-01

    Full Text Available En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróleo en proporciones hasta del 15%, sin que la mezcla resultante se salga de las especificaciones de calidad estipuladas en los estándares nacionales e internacionales para combustibles diesel. La mayor dificultad para el uso del biodiesel de aceite de higuerilla en motores es su alta viscosidad. Sin embargo este biocombustible presenta excelentes propiedades de flujo a baja temperatura (valores bajos para los puntos de nube y fluidez. Las pruebas en motor con mezclas biodiesel de higuerilla/diesel convencional, en el rango de proporciones de biodiesel ensayadas, muestran que ha medida que se incrementa la proporción de biodiesel en la mezcla aumenta el consumo específico de combustible, disminuye el dosado relativo, la opacidad de humos se disminuye levemente, mientras que el rendimiento efectivo y las emisiones de CO y CO2 prácticamente permanecen constantes

  18. Quem é o outro, o diferente? Reflexões sobre psicanálise e educação

    Directory of Open Access Journals (Sweden)

    Cristiana Carneiro

    2016-08-01

    Full Text Available O presente artigo pretende pensar a concepção de destino em Freud como conceito que implica necessariamente uma reflexão acerca da natureza humana, já que se refere à trajetória temporal dos sujeitos. Tal iniciativa, a nosso ver, enriquece uma discussão quanto ao lugar do outro na ação educativa, questionamento indispensável para que uma prática inclusiva seja possível. As concepções de destino comportam significações para “natureza humana” que influenciam a prática, já que incidem sobre o ideário que temos do outro. É nesta direção que a psicanálise nos indica um caminho: o conhecimento da verdade e desejo do próprio sujeito. Neste caso, a diferença não diria respeito apenas ao outro, mas refere-se ao próprio desconhecimento que cada um tem para consigo mesmo. Aceitar a diferença é poder conviver com a nossa própria condição de desconhecimento em relação a nós mesmos, é visualizar que o caminho humano estará sempre marcado por certa errância.

  19. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    Directory of Open Access Journals (Sweden)

    Nureddin Dinler

    2010-01-01

    Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

  20. The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

    International Nuclear Information System (INIS)

    Prayitno; Sukosrono

    2007-01-01

    The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

  1. Reality show: um paradoxo nietzschiano

    Directory of Open Access Journals (Sweden)

    Ilana Feldman

    2011-01-01

    Full Text Available

    O fenômeno dos reality shows - e a subseqüente relação entre imagem e verdade - assenta-se sobre uma série de paradoxos. Tais paradoxos podem ser compreendidos à luz do pensamento do filósofo alemão Friedrich Nietzsche, que, através dos usos de formulações paradoxais, concebia a realidade como um mundo de pura aparência e a verdade como um acréscimo ficcional, como um efeito. A ficção é então tomada, na filosofia de Nietzsche, não em seu aspecto falsificante e desrealizador - como sempre pleiteou nossa tradição metafísica -, mas como condição necessária para que certa espécie de invenção possa operar como verdade. Sendo assim, a própria expressão reality show, através de sua formulação paradoxal, engendra explicitamente um mundo de pura aparência, em que a verdade, a parte reality da proposição, é da ordem do suplemento, daquilo que se acrescenta ficcionalmente - como um adjetivo - a show. O ornamento, nesse caso, passa a ocupar o lugar central, apontando para o efeito produzido: o efeito-de-verdade. Seguindo, então, o pensamento nietzschiano e sua atualização na contemporaneidade, investigaremos de que forma os televisivos “shows de realidade” operam paradoxalmente, em consonância com nossas paradoxais práticas culturais.

  2. Biofuels combustion.

    Science.gov (United States)

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  3. Low emission internal combustion engine

    Science.gov (United States)

    Karaba, Albert M.

    1979-01-01

    A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

  4. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

    2014-01-01

    . While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

  5. Diesel oil combustion in fluidized bed; Combustion de aceite diesel en lecho fluidizado

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Cazares, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-07-01

    The effect of the fluidized bed depth in the combustion in burning diesel oil in a fluidized bed, was analyzed. A self sustained combustion was achieved injecting the oil with an injector that utilized a principle similar to an automobile carburetor venturi. Three different depths were studied and it was found that the deeper the bed, the greater the combustion efficiency. Combustion efficiencies were attained from 82% for a 100mm bed depth, up to 96% for a 200mm bed depth. The diminution in the efficiency was mainly attributed to unburned hydrocarbons and to the carbon carried over, which was observed in the black smoke at the stack outlet. Other phenomena registered were the temperature gradient between the lower part of the bed and the upper part, caused by the fluidization velocity; additionally it was observed that the air employed for the oil injection (carbureting air) is the most important parameter to attain a complete combustion. [Espanol] Se analizo el efecto de la profundidad del lecho en la combustion al quemar aceite diesel en un lecho fluidizado experimental. Se logro combustion autosostenida inyectando el aceite con un inyector que utilizo un principio similar al venturi del carburador de automovil. Se estudiaron tres diferentes profundidades del lecho y se encontro que a mayor profundidad del lecho, mayor eficiencia de la combustion. Se lograron eficiencias de la combustion desde 82% para el lecho de 100 mm de profundidad hasta 96% para el de 200 mm. La disminucion de la eficiencia se atribuyo, principalmente, a los hidrocarburos no quemados y al carbon arrastrado, lo cual se observo en el humo negro a la salida de la chimenea. Otros fenomenos registrados fueron el gradiente de temperatura entre la parte baja del lecho y la parte superior causado por la velocidad de fluidizacion; ademas, se observo que el aire utilizado para inyectar el aceite (aire de carburacion) es el parametro mas importante para lograr una combustion completa.

  6. Transient flow combustion

    Science.gov (United States)

    Tacina, R. R.

    1984-01-01

    Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

  7. Shale oil combustion

    International Nuclear Information System (INIS)

    Al-dabbas, M.A.

    1992-05-01

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

  8. Shale oil combustion

    Energy Technology Data Exchange (ETDEWEB)

    Al-dabbas, M A

    1992-05-01

    A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

  9. Depoimento sem dano: a escuta da psicanálise ou a escuta do direito?

    Directory of Open Access Journals (Sweden)

    Conte, Bárbara de Souza

    2008-01-01

    Full Text Available O depoimento sem dano é uma prática de inquirição de crianças supostamente vitimas de abuso sexual, que está sendo introduzido no Poder Judiciário, onde o inquérito é realizado por psicólogo. Problematizo, em um primento ponto, a verdade do discurso produzido pela criança em uma situação de depoimento, buscando discutir o que se chama em psicanálise de verdade histórico - vivencial a partir do traumático do acontecimento e suas consequëncias psíquicas. Em um segundo ponto, interrogo sobre a certeza da prova e as formas de escuta e intervenção desde uma perspectiva ética do fazer do psicólogo

  10. A psicologia em História da Loucura de Michel Foucault

    Directory of Open Access Journals (Sweden)

    Fernando de Almeida Silveira

    2009-04-01

    Full Text Available Michel Foucault investiga "a história das relações que o pensamento mantém com a verdade" e desnaturaliza corpo, alma e psiqué considerando-os invenções histórico-discursivas, as quais só têm sentido se inseridas em determinados arranjos epistêmicos de produção de verdades, no caso, o surgimento das ciências humanas. Esta pesquisa estuda a ordem do discurso foucaultiano sobre a Psicologia em sua fase arqueológica, no livro História da Loucura, com o intuito de oferecer subsídios para a compreensão da história dos discursos da Psicologia, no que se refere à edificação do sujeito e do objeto psicológicos e em seus efeitos subjetivadores.

  11. Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion.

    Science.gov (United States)

    Chien, Y C; Yang, S H

    2013-01-01

    Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.

  12. O conceito de pós-modernidade em Lyotard e a possibilidade da influência nietzschiana Felipe Szyszka Karasek

    Directory of Open Access Journals (Sweden)

    Karasek, Felipe Szyszka

    2010-01-01

    Full Text Available O principal objetivo deste estudo é apresentar a tese que os elementos constituintes da reflexão de Lyotard sobre a pós-modernidade já estavam presentes nas suspeitas e na filosofia de Friedrich Nietzsche. Realizando um estudo genealógico sobre a crítica de Nietzsche ao socratismo, pretendemos demonstrar que a desconfiança de verdades já fazia parte do perspectivismo nietzschiano, bem como a crítica às legitimações metafísicas. Pretendemos, dessa maneira, apresentar a possibilidade da influência da filosofia nietzschiana na formação do pensamento de Lyotard sobre o conceito de pós-moderno

  13. Passagem da compreensão à verdade: contribuição do estruturalismo à teoria lacaniana da psicose

    Directory of Open Access Journals (Sweden)

    Léa Silveira Sales

    2007-12-01

    Full Text Available A argumentação procura mostrar que é a inserção na racionalidade estruturalista que finalmente conduz Lacan a providenciar a descrição de um dispositivo específico na causação da psicose, permitindo, através da distinção entre conhecimento e verdade, a superação dos impasses de sua tese de doutorado, então baseada em critérios de assentimento social e na tentativa de sobrepor explicação e compreensão.Passage from comprehension to truth: structuralism’s contribution to the Lacanian psychosis theory. From comprehension to truth: structuralism’s contribution Lacanian theory of psychosis. The argument tries to show that it is the insertion into the structuralist rationality that finally leads Lacan to provide the description of a specific device in the causation of psychosis, allowing, through the distinction between knowledge and truth, the overcoming of the impasses of his doctoral thesis, then based on criteria of social consent and on the attempt to overlap explanation and comprehension.

  14. The Multi-User Droplet Combustion Apparatus: the Development and Integration Concept for Droplet Combustion Payloads in the Fluids and Combustion Facility Combustion Integrated Rack

    Science.gov (United States)

    Myhre, C. A.

    2002-01-01

    The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility designed to accommodate four different droplet combustion science experiments. The MDCA will conduct experiments using the Combustion Integrated Rack (CIR) of the NASA Glenn Research Center's Fluids and Combustion Facility (FCF). The payload is planned for the International Space Station. The MDCA, in conjunction with the CIR, will allow for cost effective extended access to the microgravity environment, not possible on previous space flights. It is currently in the Engineering Model build phase with a planned flight launch with CIR in 2004. This paper provides an overview of the capabilities and development status of the MDCA. The MDCA contains the hardware and software required to conduct unique droplet combustion experiments in space. It consists of a Chamber Insert Assembly, an Avionics Package, and a multiple array of diagnostics. Its modular approach permits on-orbit changes for accommodating different fuels, fuel flow rates, soot sampling mechanisms, and varying droplet support and translation mechanisms to accommodate multiple investigations. Unique diagnostic measurement capabilities for each investigation are also provided. Additional hardware provided by the CIR facility includes the structural support, a combustion chamber, utilities for the avionics and diagnostic packages, and the fuel mixing capability for PI specific combustion chamber environments. Common diagnostics provided by the CIR will also be utilized by the MDCA. Single combustible fuel droplets of varying sizes, freely deployed or supported by a tether are planned for study using the MDCA. Such research supports how liquid-fuel-droplets ignite, spread, and extinguish under quiescent microgravity conditions. This understanding will help us develop more efficient energy production and propulsion systems on Earth and in space, deal better with combustion generated pollution, and address fire hazards associated with

  15. Demos com o colosso em terra: o ocaso de José Bonifácio e a ascensão política de Aureliano Coutinho nas páginas do jornal A Verdade

    Directory of Open Access Journals (Sweden)

    Julio Bentivoglio

    2010-12-01

    Full Text Available Este artigo analisa a campanha movida por Aureliano Coutinho para destituir José Bonifácio da tutoria do futuro imperador Pedro II, travada a partir de seu jornal A Verdade entre 1832 e 1834. Indica como esta ação foi decisiva para a trajetória política de Aureliano, futuro visconde de Sepetiba, para alcançar a preeminência palaciana na corte imperial brasileira.

  16. RELAÇÕES PÚBLICAS E INTELIGÊNCIA PROFISSIONAL: A COMPLEXIDADE INTERDISCIPLINAR VIVA

    Directory of Open Access Journals (Sweden)

    Valdemarina Bidone de Azevedo e Souza

    2016-11-01

    Full Text Available Nas organizações há uma busca incessante em descobrir certezas e verdades, num contexto caracterizado pela incerteza e por verdades provisórias, refletindo a necessidade de novas configurações e definições de relacionamentos, novos paradigmas que possam auxiliar no reconstrução das práticas. Neste contexto, pensar sobre uma inteligência profissional significa concebê-la como a aptidão organizacional para pensar e criar estratégias em situações de complexidade (MORIN, 1998. A partir da necessidade de ampliar conhecimentos sobre práticas cotidianas do profissional de Relações Públicas, defende-se a idéia da utilização de uma abordagem interdisciplinar em razão da complexidade existencial do ser humano e das organizações. Neste sentido, a mediação em nível organizacional cabe ser gerenciada por um profissional de Relações Públicas, a partir de informações obtidas pela interação com profissionais de outras áreas. Palavras-chave: Inteligência Profissional, Relações Públicas, Interdisciplinaridade.

  17. Large-eddy simulation of ethanol spray combustion using a finite-rate combustion model

    Energy Technology Data Exchange (ETDEWEB)

    Li, K.; Zhou, L.X. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics; Chan, C.K. [Hong Kong Polytechnic Univ. (China). Dept. of Applied Mathematics

    2013-07-01

    Large-eddy simulation of spray combustion is under its rapid development, but the combustion models are less validated by detailed experimental data. In this paper, large-eddy simulation of ethanol-air spray combustion was made using an Eulerian-Lagrangian approach, a subgrid-scale kinetic energy stress model, and a finite-rate combustion model. The simulation results are validated in detail by experiments. The LES obtained statistically averaged temperature is in agreement with the experimental results in most regions. The instantaneous LES results show the coherent structures of the shear region near the high-temperature flame zone and the fuel vapor concentration map, indicating the droplets are concentrated in this shear region. The droplet sizes are found to be in the range of 20-100{mu}m. The instantaneous temperature map shows the close interaction between the coherent structures and the combustion reaction.

  18. Impacts of Combustion Conditions and Photochemical Processing on the Light Absorption of Biomass Combustion Aerosol.

    Science.gov (United States)

    Martinsson, J; Eriksson, A C; Nielsen, I Elbæk; Malmborg, V Berg; Ahlberg, E; Andersen, C; Lindgren, R; Nyström, R; Nordin, E Z; Brune, W H; Svenningsson, B; Swietlicki, E; Boman, C; Pagels, J H

    2015-12-15

    The aim was to identify relationships between combustion conditions, particle characteristics, and optical properties of fresh and photochemically processed emissions from biomass combustion. The combustion conditions included nominal and high burn rate operation and individual combustion phases from a conventional wood stove. Low temperature pyrolysis upon fuel addition resulted in "tar-ball" type particles dominated by organic aerosol with an absorption Ångström exponent (AAE) of 2.5-2.7 and estimated Brown Carbon contributions of 50-70% to absorption at the climate relevant aethalometer-wavelength (520 nm). High temperature combustion during the intermediate (flaming) phase was dominated by soot agglomerates with AAE 1.0-1.2 and 85-100% of absorption at 520 nm attributed to Black Carbon. Intense photochemical processing of high burn rate flaming combustion emissions in an oxidation flow reactor led to strong formation of Secondary Organic Aerosol, with no or weak absorption. PM1 mass emission factors (mg/kg) of fresh emissions were about an order of magnitude higher for low temperature pyrolysis compared to high temperature combustion. However, emission factors describing the absorption cross section emitted per kg of fuel consumed (m(2)/kg) were of similar magnitude at 520 nm for the diverse combustion conditions investigated in this study. These results provide a link between biomass combustion conditions, emitted particle types, and their optical properties in fresh and processed plumes which can be of value for source apportionment and balanced mitigation of biomass combustion emissions from a climate and health perspective.

  19. Engine combustion network (Ecn) : characterization and comparison of boundary conditions for different combustion vessels

    NARCIS (Netherlands)

    Meijer, M.; Somers, L.M.T.; Johnson, J.; Naber, J.; Lee, S.Y.; Malbec, L.M.; Bruneaux, G.; Pickett, L.M.; Bardi, M.; Payri, R.; Bazyn, T.

    2012-01-01

    The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels and/or performing computational fluid dynamics (CFD) simulation, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray

  20. Optimization of combustion chamber geometry for stoichiometric diesel combustion using a micro genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Wook

    2010-11-15

    This paper describes the optimization of combustion chamber geometry and engine operating conditions for stoichiometric diesel combustion, targeting lower gross indicated specific fuel consumption. The KIVA code, coupled with a micro genetic algorithm population of nine for each generation was used. The optimization variables were composed of ten variables related to the combustion chamber geometry and engine operating conditions. In addition, an auto mesh generator was developed for generating various kinds of combustion chambers, such as open-crater, re-entrant, deep, and shallow types. In addition, the computational models were validated against the experimental results for a stoichiometric process in terms of the combustion pressure history and emissions. Through the preset optimization, a 35% improvement in the gross indicated that specific fuel consumption was achieved. In addition, the optimization results showed that the optimum engine operating conditions employed a premixed charge compression ignition combustion regime with early injection and a narrow spray included angle. Furthermore, a higher boost pressure was used to prevent fuel film formation. (author)

  1. Batuque: a identidade nos corpos = Batuque: the identity in the bodies

    Directory of Open Access Journals (Sweden)

    Roselene de Fátima Coito

    2008-07-01

    Full Text Available Michel Foucault, ao abordar os usos da História como o uso paródico darealidade, o uso dissociativo da identidade e o uso sacrificial da verdade, leva-nos a refletir sobre o que é a História sob a ótica da genealogia, a qual revela que a origem como se concebe tradicionalmente, ou seja, linearmente, é questionável enquanto uma verdade atribuída por um conhecimento (ou um querer-saber que percorre a humanidade. O querer-saber de onde viemos e para onde vamos tem suscitado reflexões variadas sobre identidade, sobre História e sobre verdade. No entanto, o que é a identidade quando se lhe atribui um caráter genealógico? O filósofo francês, partindo de Nietzsche, propõe dois olhares para essa discussão: a emergência ou o ponto de surgimento com o possibilidade de reflexão sobre a origem, cujo termo em alemão é Entestehung, ou o corpo como superficie deinscrições dos acontecimentos, cujo termo em alemão é Herkunft. É partindo deste segundo olhar que discutiremos o batuque, uma dança africana acompanhada de música, como uma prática que institui e constitui a identidade do africano que veio habitar o Brasil.Analyzing the uses of History as the parodic use of reality, the dissociative use of identity and the sacrificial use of truth, MichelFoucault investigates the meaning of History from the perspective of genealogy. Genealogy discloses that origin as traditional conceived, as a linear factor, is problematic as a truth attributed by knowledge (or desire-knowledge involving mankind. The desire-knowledgeon our origin and our destiny has stimulated several reflections on identity, history and truth. Nevertheless, what does identity mean when a genealogical character is attributed to it? Based on Nietzsche’s suppositions, the French philosopher presents two explanations to this discussion: emergency or the point of arising as a possibility for reflections on origin (Entstehung in German, or the body as a surface of events

  2. Multi-stage combustion using nitrogen-enriched air

    Science.gov (United States)

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  3. Para inspirar confiança: considerações sobre a formação moral em Kant To inspire trust: considration about the moral formation in Kant

    Directory of Open Access Journals (Sweden)

    Mário Nogueira de Oliveira

    2006-01-01

    Full Text Available Este artigo trata da formação moral do homem segundo Kant. Para ele, "o homem, afetado por tantas inclinações, é na verdade capaz de conceber a idéia de uma razão pura prática, mas não é tão facilmente dotado da força necessária para a tornar eficaz in concreto no seu comportamento". Deste modo, para implementar nossas máximas de comportamento Kant elabora seu estudo sobre a formação do homem para leva-lo a uma vida livre e moral.This article treats the concept of moral formation according to Kant. He sustains that "man, affected by many inclinations, is able to conceive the idea of a pure practical reason, but is not equally able to make it effective in his behavior". So, in order to improve our maxims of behavior Kant elaborates his study on man education in order to lead him to freedom and morality.

  4. DIAGNOSIS OF FAILURE OF COMBUSTION IN THE COMBUSTION CHAMBER WITH A THERMOVISION EQUIPMENT

    Directory of Open Access Journals (Sweden)

    S. V. Vorobiev

    2014-01-01

    Full Text Available The use of thermovision technology to diagnose failure of the combustion flame test tube of the main combustion chamber gas turbine engine is deal with in the article. Join the thermal radiation of the jet of combustion products and the internal elements was carried out using short-wave thermovision system AGA-782 with spectral spectral filters in several ranges from 3.2 to 5.6 microns. Thermovision is mounted on the axis of the flame tube. The output signal was recorded and processed on a computer in real time, allowing monitor the combustion process and the thermal state of the object during the experiment.

  5. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  6. Avaliação da avaliação da pós-graduação em educação do Brasil: quanta verdade é suportável?

    Directory of Open Access Journals (Sweden)

    Amarildo Luiz Trevisan

    2013-07-01

    Full Text Available O sistema de avaliação dos programas de pós-graduação em Educação no Brasil vem sofrendo muitos questionamentos desde a sua origem. São muitas controvérsias que apontam para a queda no argumento de que tal sistema se justifica pela busca da excelência. Por trás desse discurso aparentemente convincente, escondem-se os seus efeitos ao longo dos últimos 40 anos: a grande concentração dos programas nas regiões centro-sul do país, tanto em nível de quantidade quanto de qualidade, além da desconsideração com a avaliação dos alunos pelo sistema. Diante disso têm-se levantado diversas dúvidas, entre elas podemos aduzir as preocupações emergentes do âmbito da Filosofia da Educação. A pergunta é se o problema não estaria na epistemologia de base subjetiva (justificação ideal a que o sistema está ancorado, com pouca referência à verdade do mundo objetivo, tanto da realidade geográfica do país quanto da aprendizagem dos alunos. Para discutir a justificativa do sistema pela busca da excelência e a sua legitimidade prática, a proposta deste artigo se baseia nos aportes da obra Verdade e Justificação, do filósofo alemão Jürgen Habermas.

  7. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  8. Space Station Freedom combustion research

    Science.gov (United States)

    Faeth, G. M.

    1992-01-01

    Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame

  9. Underground treatment of combustible minerals

    Energy Technology Data Exchange (ETDEWEB)

    Sarapuu, E

    1954-10-14

    A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

  10. Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

    KAUST Repository

    An, Yanzhao

    2017-09-23

    In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

  11. Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

    KAUST Repository

    An, Yanzhao; Jaasim, Mohammed; Vallinayagam, R.; Vedharaj, S.; Im, Hong G.; Johansson, Bengt.

    2017-01-01

    In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

  12. Fuels and Combustion | Transportation Research | NREL

    Science.gov (United States)

    Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

  13. Pobreza, racismo y competitividad. El ordenamiento urbano neoliberal en Cartagena de Indias

    Directory of Open Access Journals (Sweden)

    Dairo Sánchez Mojica

    2015-01-01

    Full Text Available El art culo propone un an lisis del discurso neoliberal sobre la plani caci n del ordenamiento urbano de Cartagena de Indias. Pa ra ello, se vale de la categor a de intertextualidad para ex- plorar las articulaciones que relacionan la prensa escrita nacional con algunos instrumentos de plani caci n urbana. Esto le permite indagar por sus efectos pol ticos de verdad sobre la gesti n gubernamental de la pobreza. Concluye que las implicaciones pol ticas de nombrar la pobreza a partir del orden discursivo neoliberal tienen que ver con el gobierno de las fuerzas creativas del cuerpo social.

  14. El concepto de «el pueblo» es más amplio que el de «la gente»

    OpenAIRE

    Ghea, María Elisa; Vialey, Patricia; Annuasi, Gonzalo

    2014-01-01

    A partir de la Resolución Nº 125 del Poder Ejecutivo Nacional argentino, en marzo de 2008, los medios de comunicación gráficos dominantes fueron actores principales en la construcción de percepciones sociales sobre la realidad de época, a la vez que constructores de verdades sobre la gestión del gobierno de Cristina Fernández. En sus páginas, el análisis de la información y su tratamiento tuvieron como eje temático el relato de conflicto permanente entre el gobierno y determinados actores eco...

  15. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

    1988-01-01

    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  16. Ultra-low pollutant emission combustion method and apparatus

    International Nuclear Information System (INIS)

    Khinkis, M.J.

    1992-01-01

    This patent describes a method for ultra-low pollutant emission combustion of fossil fuel. It comprises: introducing into a primary combustion chamber a first fuel portion of about 1 percent to about 20 percent of a total fuel to be combusted; introducing primary combustion air into the primary combustion chamber; introducing a first portion of water into the primary combustion chamber, having a first water heat capacity equivalent to a primary combustion air heat capacity of one of a primary combustion air amount of about 10 percent to about 60 percent of the first stoichiometirc requirement for complete combustion of the first fuel portion and an excess primary combustion air amount of about 20 percent to about 150 percent of the first stoichiometric requirement for complete combustion of the first fuel portion; burning the first fuel portion with the primary combustion air in the primary combustion chamber at a temperature abut 2000 degrees F to about 2700 degrees F producing initial combustion products; passing the initial combustion products into a secondary combustion chamber; introducing into the secondary combustion chamber a second fuel portion of about 80 percent to about 99 percent of the total fuel to be combusted; introducing secondary combustion air into the secondary combustion chamber in an amount of about 105 percent to about 130 percent of a second stoichiometric requirement for complete combustion of the second fuel portion; introducing a second portion of water into the secondary combustion chamber; burning the second fuel portion and any remaining fuel in the initial combustion products; passing the final combustion products into a dilution chamber; introducing dilution air into the dilution chamber; discharging the ultra-low pollutant emission vitiated air form the dilution chamber

  17. ANALYSIS OF INTERNAL COMBUSTION ENGINE WITH A NEW CONCEPT OF POROUS MEDIUM COMBUSTION FOR THE FUTURE CLEAN ENGINE

    Directory of Open Access Journals (Sweden)

    Ashok A Dhale

    2010-01-01

    Full Text Available At present, the emissions of internal combustion engine can only be improved by catalytic treatments of the exhaust gases. Such treatments, however, result in high costs and relatively low conversion efficiency. This suggests that a new combustion technique should be developed to yield improved primary combustion processes inside the engine with drastically reduced exhaust gas emissions. To fulfill all requirements, Dr. Franz Drust has proposed a new combustion concept to perform homogenous combustion in internal combustion engines. This concept used the porous medium combustion technique and is called "PM-engine". It is shown that the PM combustion technique can be applied to internal combustion engines. Theoretical considerations are presented for internal combustion engines, indicating that an overall improvement in thermal efficiency can be achieved for the PM-engine. This is explained and general performance of the new PM-engines is demonstrated for a single cylinder, water cooled, direct injection diesel engine. Verification of experiments at primary stage is described that were carried out as a part of the present study.

  18. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  19. Aprender de la imaginación

    Directory of Open Access Journals (Sweden)

    Carola Barbero

    2017-09-01

    Full Text Available El problema del valor cognitivo de las obras literarias ha recibido fundamentalmente dos tipos de respuesta,  la cognitivista y la anti-cognitivista, la primera sostiene que la literatura es vehículo de verdades universales y la segunda mantiene que no transmite nada salvo falsedades y trivialidades. Entre estas posiciones opuestas, este ensayo defiende una forma de cognitivismo débil afirmando por una parte, con los cognitivistas, la idea de que aprendemos de la literatura, y por otra parte, con los anti-cognitivistas, la intuición de que la literatura no nos transmite (en primera instancia verdades sobre nosotros mismos o sobre el mundo.La idea es que una solución basada en dos niveles, de acuerdo con lo que aprendemos de la literatura, se deriva de una combinación de knowing that y knowing what. En primer lugar, para aprender algo de la literatura necesitamos comprender, y por tanto saber, de qué hablan los textos literarios, tenemos que ser capaces de aferrar el estado de cosas descrito. Este es el primer nivel, relativo a la verdad literaria y al knowing that. En un segundo nivel, nuestro aprendizaje a partir de los textos literarios tiene que ver con imaginar cómo es ser esos personajes involucrados en esos eventos, por lo tanto, knowing what es como vivir una vida diferente de la propia. En este nivel aprendemos de la literatura del mismo modo en que aprendemos de los experimentos mentales, ejemplos o contraejemplos. Esto es lo que Hilary Putnam ha llamado “conocimiento conceptual de vidas posibles

  20. Indoor combustion and asthma.

    Science.gov (United States)

    Belanger, Kathleen; Triche, Elizabeth W

    2008-08-01

    Indoor combustion produces both gases (eg, nitrogen dioxide, carbon monoxide) and particulate matter that may affect the development or exacerbation of asthma. Sources in the home include both heating devices (eg, fireplaces, woodstoves, kerosene heaters, flued [ie, vented] or nonflued gas heaters) and gas stoves for cooking. This article highlights the recent literature examining associations between exposure to indoor combustion and asthma development and severity. Since asthma is a chronic condition affecting both children and adults, both age groups are included in this article. Overall, there is some evidence of an association between exposure to indoor combustion and asthma, particularly asthma symptoms in children. Some sources of combustion such as coal stoves have been more consistently associated with these outcomes than other sources such as woodstoves.

  1. A tempestade global da lei e ordem: sobre punição e neoliberalismo

    Directory of Open Access Journals (Sweden)

    Loïc Wacquant

    2012-02-01

    Full Text Available Este artigo reflete sobre a recepção internacional ao livro Prisões da miséria como reveladora da expansão penal nas sociedades avançadas na década de 2000. Ele revela que a tempestade global da "lei e ordem" inspirada pelos Estados Unidos, que o livro detectou em 1999, continuou a espalhar-se por toda a parte. Na verdade, ela estendeu-se dos países do Primeiro Mundo para os do Segundo Mundo e alterou a política e as práticas de punição em todo o globo de uma forma que ninguém previa e que ninguém teria pensado como possível há cerca de 15 anos. O artigo estende a análise para o papel dos institutos de consultoria (em especial o Manhattan Institute na difusão das noções de combate ao crime e das panacéias no estilo estadunidense na América Latina como um elemento da circulação internacional dos pacotes de política pró-mercado que alimentam a gerência punitiva da pobreza. O artigo elabora e revê o modelo original do nexo entre neoliberalismo e penalidade punitiva, levando a análise da montagem do Estado na era da insegurança social, desenvolvida no livro Punindo os pobres.

  2. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

  3. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  4. Discurso e "verdade": a produção das relações entre mulheres, homens e matemática Discourse and "truth": the production of the relationships between women, men and mathematics

    Directory of Open Access Journals (Sweden)

    Maria Celeste Reis Fernandes de Souza

    2009-08-01

    Full Text Available Este trabalho apresenta um ensaio de análise desenvolvido numa pesquisa que investigou relações de gênero nas práticas de numeramento das/os alunas/os da Educação de Pessoas Jovens e Adultas (EJA. Na tentativa de compreender como essas relações, pautadas nas diferenças de gênero, constituem-se nas práticas de numeramento e constituem tais práticas, adotamos o conceito de gênero como uma categoria de análise, transitando pelas teorizações foucaultianas relativas ao discurso. Assumindo contribuições do campo da etnomatemática, problematizamos a racionalidade de matriz cartesiana como produtora de verdades sobre mulheres, homens e matemática. Neste artigo, descrevemos o enunciado "Homem é melhor em matemática do que mulher", identificado como produtor do discurso da superioridade masculina em matemática.This work presents an analysis essay developed in a research which investigated the gender relations in numeracy practices of male and female students in Youth and Adult Education (EJA. As an attempt to understand how these relations - based on gender differences - are constituted by numeracy practices and, at the same time, how they constitute such practices, we adopt the gender concept as an analysis category, passing through Foucaultian theorizations related to discourse. Taking into consideration the contributions from Ethnomathematics, we point to the rationality of the Cartesian matrix as the producer of truths about women, men and mathematics. This article describes the utterance "Man is better in math than woman", which was identified as a discourse maker of male superiority in mathematics.

  5. Large eddy simulation and combustion instabilities; Simulation des grandes echelles et instabilites de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lartigue, G.

    2004-11-15

    The new european laws on pollutants emission impose more and more constraints to motorists. This is particularly true for gas turbines manufacturers, that must design motors operating with very fuel-lean mixtures. Doing so, pollutants formation is significantly reduced but the problem of combustion stability arises. Actually, combustion regimes that have a large excess of air are naturally more sensitive to combustion instabilities. Numerical predictions of these instabilities is thus a key issue for many industrial involved in energy production. This thesis work tries to show that recent numerical tools are now able to predict these combustion instabilities. Particularly, the Large Eddy Simulation method, when implemented in a compressible CFD code, is able to take into account the main processes involved in combustion instabilities, such as acoustics and flame/vortex interaction. This work describes a new formulation of a Large Eddy Simulation numerical code that enables to take into account very precisely thermodynamics and chemistry, that are essential in combustion phenomena. A validation of this work will be presented in a complex geometry (the PRECCINSTA burner). Our numerical results will be successfully compared with experimental data gathered at DLR Stuttgart (Germany). Moreover, a detailed analysis of the acoustics in this configuration will be presented, as well as its interaction with the combustion. For this acoustics analysis, another CERFACS code has been extensively used, the Helmholtz solver AVSP. (author)

  6. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

    1995-10-01

    Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

  7. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  8. Auxiliares e Técnicos de enfermagem e controle de infecção hospitalar em centro cirúrgico: mitos e verdades Auxiliares y técnicos de enfermería y control de infección hospitalaria en centro quirúrgico: mitos y verdades Nursing auxiliaries and technicians and hospital infection control in surgical centers: myths and truths

    Directory of Open Access Journals (Sweden)

    Sônia Regina Melon Kunzle

    2006-06-01

    Full Text Available Este estudo analítico descritivo objetivou detectar conceitos que traduzem mitos e verdades relativos à infecção hospitalar entre auxiliares e técnicos de enfermagem no centro cirúrgico de três hospitais. O instrumento para coleta de dados possui 28 afirmações (15 verdadeiras e 13 falsas contemplando fatores relacionados ao paciente, equipe cirúrgica, ambiente, procedimentos. As afirmações contêm escala em três pontos (concordo, tenho dúvida, discordo. Obtivemos respostas adequadas em 72% e não adequadas em 28%, indicando o satisfatório conhecimento da enfermagem perioperatória relacionadas ao controle infecção hospitalar . Nos itens uso de pro-pé, alianças e outros objetos, pêlo como patógeno, escovação das mãos, uso de avental e campo cirúrgico umedecidos, cirurgia infectada e rotina de limpeza, doenças ocupacionais, infecção hospitalar, infecção sítio cirúrgico e tempo operatório, pudemos detectar mitos e rituais referentes ao controle de infecção, que estão relacionados sobretudo à cultura de quem os praticam, perpetuando resistência a mudanças.Este estudio analítico descriptivo tuvo como objetivo detectar conceptos que traduzcan mitos y verdades relativas a la infección hospitalaria entre auxiliares y técnicos de enfermería en el centro quirúrgico de tres hospitales. El instrumento de recolección de datos contenía 28 afirmaciones (15 verdaderas y 13 falsas que contemplaba factores relacionados al paciente, equipo quirúrgico, ambiente, procedimientos. Las afirmaciones contienen escala en tres puntos (concuerdo, tengo duda, desacuerdo. Obtuvimos respuestas adecuadas en el 72% y no adecuadas en el 28%, indicando el conocimiento satisfactorio de la enfermería perioperatoria relacionadas al control de la infección hospitalaria. En los items uso de botas quirúrgicas, anillos y otros objetos, pelo como patógeno, cepillado de las manos, uso del mandil y campo quirúrgico humedecidos, cirug

  9. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao

    1988-01-01

    An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

  10. Molten salt combustion of radioactive wastes

    International Nuclear Information System (INIS)

    Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

    1976-01-01

    The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

  11. Experimental study of improvement on combustion control of fluidized bed combustion chamber; Ryudosho shokyakuro no nenshosei no kaizen ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Izumiya, T.; Baba, K.; Koshida, H.; Uetani, J.; Furuta, M.

    1998-10-29

    Nippon Steel Corporation has carried out an experimental study using the Yawata waste incinerator plant in order to improve combustion control of a fluidized bed combustion chamber. For controlling the forming of dioxin, combustion control is very important in addition to conventional methods. In this paper, we report two studies about improvements on combustion control. In the first study, we verified improvement on combustion control by modifying gas flow at the freeboard. The operational results of the experiments were studied using the numerical model of the combustion chamber. The modification of gas flow at freeboard was confirmed to be effective to obtain a compact design of fluidized bed combustion chamber for municipal waste. In the second, study we improved combustion control for sewage combustion with municipal waste. In burning municipal waste and sewage, it is especially required to take combustion control into careful consideration. In this experiment, we developed a new device for supplying sewage for the appropriate controlling combustion, and verified its effectiveness to combustion control and an effective reduction of dioxin. (author)

  12. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  13. Combustion means for solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Murase, D.

    1987-09-23

    A combustion device for solid fuel, suitable for coal, coke, charcoal, coal-dust briquettes etc., comprising:- a base stand with an opening therein, an imperforate heat resistant holding board locatable to close said opening; a combustion chamber standing on the base stand with the holding board forming the base of the combustion chamber; a wiper arm pivoted for horizontal wiping movement over the upper surface of the holding board; an inlet means at a lower edge of said chamber above the base stand, and/or in a surrounding wall of said chamber, whereby combustion air may enter as exhaust gases leave the combustion chamber; an exhaust pipe for the exhaust gases; generally tubular gas-flow heat-exchange ducting putting the combustion chamber and exhaust pipe into communication; and means capable of moving the holding board into and out of the opening for removal of ash or other residue. The invention can be used for a heating system in a house or in a greenhouse or for a boiler.

  14. Combustion of Waste Wood. Second phase of the collaboration project on waste wood combustion

    International Nuclear Information System (INIS)

    Andersson, Annika; Andersson, Christer; Eriksson, Jan; Hemstroem, Bengt; Jungstedt, Jenny; Kling, Aasa; Bahr, Bo von; Ekvall, Annika; Eskilsson, David; Tullin, Claes; Harnevie, Henrik; Sieurin, Jan; Keihaes, Juha; Mueller, Christian; Berg, Magnus; Wikman, Karin

    2003-08-01

    Combustion of waste wood has during the last decade increased dramatically and this has resulted in a number of Swedish plants using this fuel, e.g. Handeloe P11 (Norrkoeping) and ldbaecken P3 (Nykoeping), and yet other plants that are under construction (e.g. Nynaeshamn). The experience from these plants are that waste wood combustion results in a number of operational problems. To some extent these problems are different compared with the problems related to combustion of other biofuels but the situation is not directly comparable to waste incinerators. The problems are mainly related to slagging and fouling of heat exchanger surfaces and accelerated corrosion at relatively low temperature compared to the situation for ordinary biofuels. In some cases an increase in the emissions of specific substances can also result in difficulties to fulfil the EC-directive on waste combustion. Within previous projects the main problems related to combustion of waste wood have been identified and to some extent the cause of these problems has been clarified. One result of this reported investigation is a deeper understanding of the actual causes of these problems. However, the most important result is a number of recommendations for different measures on how to achieve disturbance-free combustion of waste wood. These recommendations actually summarises the most important possible solutions on how to achieve a disturbance-free operation and a lower maintenance cost for boilers combusting waste wood and can thereby be regarded as a short summery of the whole project: 1) Improving fuel quality by Improved sorting at the source and Sieving of the fuel -> Reducing the amount of metals and chlorine and Separation of fines and thereby reducing the amount of metals. 2) Combustion modifications by Avoiding reducing conditions at the heat exchanger surfaces -> Minimising slagging, fouling and corrosion. 3) Additives or co-combustion by Addition of sulphur with the fuel; Injection of

  15. Novel approaches in advanced combustion characterization of fuels for advanced pressurized combustion

    Energy Technology Data Exchange (ETDEWEB)

    Aho, M.; Haemaelaeinen, J. [VTT Energy (Finland); Joutsenoja, T. [Tampere Univ. of Technology (Finland)

    1996-12-01

    This project is a part of the EU Joule 2 (extension) programme. The objective of the research of Technical Research Centre of Finland (VTT) is to produce experimental results of the effects of pressure and other important parameters on the combustion of pulverized coals and their char derivates. The results can be utilized in modelling of pressurized combustion and in planning pilot-scale reactors. The coals to be studied are Polish hvb coal, French lignite (Gardanne), German anthracite (Niederberg) and German (Goettelbom) hvb coal. The samples are combusted in an electrically heated, pressurized entrained flow reactor (PEFR), where the experimental conditions are controlled with a high precision. The particle size of the fuel can vary between 100 and 300 {mu}m. The studied things are combustion rates, temperatures and sizes of burning single coal and char particles. The latter measurements are performed with a method developed by Tampere University of Technology, Finland. In some of the experiments, mass loss and elemental composition of the char residue are studied in more details as the function of time to find out the combustion mechanism. Combustion rate of pulverized (140-180 {mu}m) Gardanne lignite and Niederberg anthracite were measured and compared with the data obtained earlier with Polish hvb coal at various pressures, gas temperatures, oxygen partial pressures and partial pressures of carbon dioxide in the second working period. In addition, particle temperatures were measured with anthracite. The experimental results were treated with multivariable partial least squares (PLS) method to find regression equation between the measured things and the experimental variables. (author)

  16. Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30

    This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables

  17. Plasma igniter for internal-combustion engines

    Science.gov (United States)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  18. Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

    NARCIS (Netherlands)

    Khan, A.A.

    2007-01-01

    This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

  19. Combustion from basics to applications

    CERN Document Server

    Lackner, Maximilian; Winter, Franz

    2013-01-01

    Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

  20. El cine como verdad rev(belada: Ken Loach; una reflexión sobre los años que forjaron el discurso naturalista del cineasta/ Cinema as rev(bealed truth: Ken Loach; a reflection over the years that forged the filmmaker’s naturalist speech

    Directory of Open Access Journals (Sweden)

    Mercedes Miguel Borrás

    2015-07-01

    Full Text Available La sabiduría que se desprende al contemplar el cine de Ken Loach, su depurado estilo naturalista, es fruto de un largo recorrido caracterizado por la coherencia y honestidad. Un cineasta que lleva más de medio siglo dejando huellas de su humanismo, dando voz a los desheredados. ¿De dónde procede su mirada? ¿Cuál es la sustancia expresiva de la que se nutre su discurso? Detenemos nuestra atención en los filmes realizados en la primera etapa de su carrera (1964-1990, pues es cuando se percibe con mayor fuerza el deseo de Loach de penetrar en la realidad con un lenguaje tan riguroso que el pensamiento parece inscribirse en la película, “un cine de confesión, de ensayo”. Una mirada, que se rebela contra un orden y una sociedad injustos, y engendra emociones insospechadas, convocando a la ternura, pero al mismo tiempo hace que nos cuestionemos lo que se nos está contando. Un cine puro, directo, sin concesiones, que reduce al mínimo los recursos. Una verdad a la que se accede de forma natural, una verdad revelada. En el calidoscopio de realidades presentes en un mismo acontecimiento, que el cine (por su naturaleza indicial e icónica es capaz de mostrar, radica esa sustancia expresiva. The Wisdom that emerges when we watch Ken Loach’s films, his refined naturalistic style, is the result of a long journey marked by consistency and honesty. A filmmaker who spend more than half a century leaving traces of their humanism, giving voice to the dispossessed. Where is the origin of the way of his looking? What is the expressive substance that nourishes his speech? We hold our attention on the films made in the first stage of his career (1964-1990, as it is when we perceive the desire of the filmmaker to penetrate in the reality with such a rigorous language that the thinking seems to enroll in the film... a cinema of confession and essay. A look, that always rebels against an order and a inherently and unjust society, and generates unexpected

  1. Combustion of diesel fuel from a toxicological perspective. I. Origin of incomplete combustion products.

    Science.gov (United States)

    Scheepers, P T; Bos, R P

    1992-01-01

    Since the use of diesel engines is still increasing, the contribution of their incomplete combustion products to air pollution is becoming ever more important. The presence of irritating and genotoxic substances in both the gas phase and the particulate phase constituents is considered to have significant health implications. The quantity of soot particles and the particle-associated organics emitted from the tail pipe of a diesel-powered vehicle depend primarily on the engine type and combustion conditions but also on fuel properties. The quantity of soot particles in the emissions is determined by the balance between the rate of formation and subsequent oxidation. Organics are absorbed onto carbon cores in the cylinder, in the exhaust system, in the atmosphere and even on the filter during sample collection. Diesel fuel contains polycyclic aromatic hydrocarbons (PAHs) and some alkyl derivatives. Both groups of compounds may survive the combustion process. PAHs are formed by the combustion of crankcase oil or may be resuspended from engine and/or exhaust deposits. The conversion of parent PAHs to oxygenated and nitrated PAHs in the combustion chamber or in the exhaust system is related to the vast amount of excess combustion air that is supplied to the engine and the high combustion temperature. Whether the occurrence of these derivatives is characteristic for the composition of diesel engine exhaust remains to be ascertained. After the emission of the particles, their properties may change because of atmospheric processes such as aging and resuspension. The particle-associated organics may also be subject to (photo)chemical conversions or the components may change during sampling and analysis. Measurement of emissions of incomplete combustion products as determined on a chassis dynamometer provides knowledge of the chemical composition of the particle-associated organics. This knowledge is useful as a basis for a toxicological evaluation of the health hazards of

  2. Enfermedad de Parkinson

    OpenAIRE

    Orozco V., Jorge Luis; Fundación Valle de Lili

    2002-01-01

    ¿Qué tan frecuente es la enfermedad de Parkinson?/ ¿Qué ocasiona la enfermedad?/ ¿Existen otras formas de Parkinsonismo?/ ¿Quién desarrolla la enfermedad de Parkinson?/ ¿Cuales son los síntomas principales?/ ¿Cómo se diagnostica la enfermedad de Parkinson?/ ¿Cómo se trata la enfermedad?/Tratamiento quirúrgico/Aspectos prácticos del tratamiento/Verdades sobre la enfermedad de Parkinson.

  3. Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

    1966-02-15

    gamma emis par les matieres radioactives qui se forment au cours du processus de fission, en particulier le spectrometre a cristal courbe, le spectrometre Compton magnetique, le spectrometre Compton a coiencidence et le spectrometre a scintillation. Parmi les autres methodes non destructives, on peut citer l'activation de feuilles, la transmission des neutrons, l'analyse par activation, la mesure des rayonnements gamma de capture et la mesure des neutrons instantanes et differes. Le memoire etudie les principes essentiels des differents appareils et procedes ci-dessus, leur precision et leurs limitations. Le memoire presente des methodes non destructives utilisant les isotopes stables produits au cours du processus de fission. Dans les mesures au moyen de ces isotopes, le schema d'irradiation n'a qu'une importance secondaire et le temps de refroidissement ne joue aucun role. De plus, on dispose de donnees nucleaires plus precises sur les produits stables de la fission. Il semble que les plus utiles de tous les isotopes stables produits au cours du processus de fission soient ceux du zirconium, du molybdene, du ruthenium et du neodyme. Le memoire etudie l'interet de ces methodes d'analyse non destructive. (author) [Spanish] Los metodos no destructivos son de gran utilidad para medir cuantitativamente el grado de combustion. El metodo ideal seria el que no requiriese datos especiales sobre los espectros neutrtfni- cos, las irradiaciones precedentes o el tiempo de enfriamiento. Los elementos combustibles irradiados llevan en cierto modo el registro de su grado de combustion. Este registro consiste en el conjunto de los isotopos radiactivos y estables resultantes del proceso de fision. Desgraciadamente, tanto con los metodos no destructivos como con los destructivos el espectro neutronico, las irradiaciones precedentes y el tiempo de enfriamiento influyen sobre dicho registro. Analogamente, la falta de datos nucleares precisos tales como las secciones eficaces nucleares

  4. Internal combustion engine

    Science.gov (United States)

    Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

    1991-01-01

    An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

  5. Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

    KAUST Repository

    Izadi Najafabadi, Mohammad

    2017-11-06

    A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

  6. Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

    2008-12-15

    Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

  7. EFECTO DE LA COMPOSICIÓN DEL GAS DE REFINERÍA SOBRE LAS CARACTERÍSTICAS DEL PROCESO DE COMBUSTIÓN

    Directory of Open Access Journals (Sweden)

    O. M. Cala

    2013-12-01

    Full Text Available En este artículo de investigación científica se analiza el efecto del cambio de la composición del gas combustible (Gas de Refinería (GR por Gas Natural (GN sobre las características del proceso combustión en hornos de la industria de refinación del petróleo; se evaluó el poder calorífico, el índice de Wobbe (IW y exceso de oxígeno, para mezclas combustibles de composición variable. Mediante simulación computacional del proceso de combustión se calculó la temperatura adiabática de llama, eficiencia y la composición de los productos de combustión. Se evaluaron mezclas de gases combustibles con poderes caloríficos entre 800-2500 Btu/pie3 y se compararon con la combustión de gas natural. Se registró variabilidad en la temperatura adiabática y la eficiencia en función de la composición del gas y el exceso de oxígeno, lo que genera inestabilidad en el horno y mayor impacto ambiental.

  8. Pressurized Fluidized Bed Combustion of Sewage Sludge

    Science.gov (United States)

    Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

    A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

  9. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    Science.gov (United States)

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  10. Thermogravimetric analysis of biowastes during combustion

    International Nuclear Information System (INIS)

    Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

    2010-01-01

    The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

  11. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  12. Oxy-fuel combustion of solid fuels

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

  13. Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

    Science.gov (United States)

    Schnauffer, Kurt

    1932-01-01

    The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

  14. Use of combustible wastes as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Salamov, A.A.

    1983-01-01

    Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

  15. Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xingcai; Ji, Libin; Ma, Junjun; Zhou, Xiaoxin; Huang, Zhen [Key Lab. for Power Machinery and Engineering of MOE, Shanghai Jiao Tong University, 200240 Shanghai (China)

    2011-02-15

    This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively according to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)

  16. Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

    Science.gov (United States)

    Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

    2018-07-01

    In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  18. Fifteenth combustion research conference

    International Nuclear Information System (INIS)

    1993-01-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

  19. Numerical analysis for controlling mixture heterogeneity to reduce abrupt combustion in diesel PCCI combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nishiwaki, Kazuie [Ritsumeikan University (Japan); Kojima, Takafumi [Takamatsu National College of Technology (Japan)

    2010-07-01

    In the energy sector, stringent regulations have been implemented on combustion emissions in order to address health and environmental concerns and help improve air quality. A novel combustion mode, premixed charge compression ignition (PCCI), can improve the emissions performance of an engine over that of conventional diesel. The aim of this research is to develop a model to analyze the mixture formation in the PCCI combustion mode. A numerical model was developed and was applied to an engine and the results were compared to experimental results. It was found that the model results are in agreement with the experimental results. This paper presented a novel LES computer model and demonstrated that it is efficient in predicting the mixture formation in the PCCI combustion mode.

  20. Modeling and simulating combustion and generation of NOx

    International Nuclear Information System (INIS)

    Lazaroiu, Gheorghe

    2007-01-01

    This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion. (author)

  1. Multi-zone modelling of PCCI combustion

    NARCIS (Netherlands)

    Egüz, U.; Somers, L.M.T.; Leermakers, C.A.J.; Goey, de L.P.H.

    2011-01-01

    Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) combustion is a promising concept for the diesel combustion. Although EDI PCCI assures very low soot and NO xemission levels, the injection is uncoupled from combustion, which narrows down the operating conditions. The main

  2. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  3. Verdad, justicia y reparación en medio de la guerra: los desplazados en Colombia

    Directory of Open Access Journals (Sweden)

    Flor Edilma Osorio Pérez

    2006-09-01

    Full Text Available À partir du groupe de victimes, peut-être le plus important, ceux qui vivent le déplacement forcé, cet article analyse les résultats et les limites du processus de vérité, de justice et de réparation durant la guerre en Colombie. Ces déplacés sont principalement caractérisés par le fait qu’ils habitent de petites commune en milieu rural. Alors qu’une politique ambiguë et contradictoire de dialogue et une démobilisation est mené auprès des groupes paramilitaires, les débats quant à la réparation des populations déplacées demandent une lecture complexe et critique des intérêts économiques et politiques en présence. En reconsidérant quelques expériences postérieures au conflit, il apparaît nécessaire de revoir le rôle de la campagne et de la société rurale dans le pays, afin d'engendrer des processus et des structures équitables dans la société colombienne, sur lesquels il soit possible de construire une réconciliation durable et intégrale.El artículo analiza los alcances y limitaciones de los procesos de verdad, justicia y reparación en medio de la guerra en Colombia, centrado en un grupo de víctimas, quizá el más numeroso: quienes viven el desplazamiento forzado. Los desplazados se caracterizan de manera importante, mas no exclusiva, por ser pobladores de municipios pequeños en contextos rurales. En medio de una política ambigua y contradictoria de diálogo y desmovilización de grupos paramilitares, se intensifican los debates frente a la reparación de las poblaciones desplazadas y se plantea la necesidad de una lectura compleja y crítica de los intereses, económicos y políticos que se entrecruzan con estas dinámicas. La revisión de algunas experiencias históricas de posconflicto, pone de relieve la importancia de reubicar el papel del campo y de la sociedad rural colombiana, en sus múltiples dimensiones, con miras a generar procesos y estructuras equitativas en la sociedad colombiana

  4. Establishment of Combustion Model for Isooctane HCCI Marine Diesel Engine and Research on the Combustion Characteristic

    Directory of Open Access Journals (Sweden)

    Li Biao

    2016-01-01

    Full Text Available The homogeneous charge compression ignition (HCCI combustion mode applied in marine diesel engine is expected to be one of alternative technologies to decrease nitrogen oxide (NOX emission and improve energy utilization rate. Applying the chemical-looping combustion (CLC mechanism inside the cylinder, a numerical study on the HCCI combustion process is performed taking a marine diesel engine as application object. The characteristic feature of combustion process is displayed. On this basis, the formation and emission of NOX are analyzed and discussed. The results indicate that the HCCI combustion mode always exhibit two combustion releasing heats: low-temperature reaction and high-temperature reaction. The combustion phase is divided into low-temperature reaction zone, high-temperature reaction zone and negative temperature coefficient (NTC zone. The operating conditions of the high compression ratio, high intake air temperature, low inlet pressure and small excess air coefficient would cause the high in-cylinder pressure which often leads engine detonation. The low compression ratio, low intake air temperature and big excess air coefficient would cause the low combustor temperature which is conducive to reduce NOX emissions. These technological means and operating conditions are expected to meet the NOX emissions limits in MARPOL73/78 Convention-Annex VI Amendment.

  5. Um crime delicado: conversando aos infinitos - "Um retrato de cavalo"

    Directory of Open Access Journals (Sweden)

    Cid Ottoni Bylaardt

    2010-12-01

    um cavalo e seu retrato, a partir dos sentimentos contraditórios de seu dono, que considera um crime aquele clique. Temos aí um retrato, imagem subtraída ilicitamente ao seu dono: escrita, representação. Temos também uma narrativa, escrita do retrato, representação da representação. Este artigo pretende mostrar como Guimarães Rosa manipula as ambiguidades da linguagem literária, levando-a além dos limites da representação, explorando seu fascínio, seu saber, que não é da ordem da compreensão. O cavalo e seu retrato fazem refletir sobre a literatura, sobre seu excesso de verdade que compõe sua mentira. Ao escrever o cavalo e seu retrato, o texto não consegue fixar nenhuma verdade, apenas imagens fugidias que compõem recapítulos: há sempre um escrito a se sobrepor a outro, sem determinar onde está o verdadeiro, onde está o que o nega, a remeter o olhar ao reino da fascinação, onde a imagem perde o valor de significação para se tornar pura paixão da indeterminação, da indiferença.

  6. Emission and combustion characteristics of multiple stage diesel combustion; Nidan nensho ni yoru diesel kikan no nensho to haishutsubutsu tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Miyamoto, T; Tsujimura, K [New A.C.E. Institute Co. Ltd., Tokyo (Japan); Kobayashi, S; Shimizu, K [Japan Automobile Research Institute, Tsukuba (Japan)

    1997-10-01

    A new concept of multiple stage diesel combustion was studied by means of engine test, combustion observation and numerical simulation, in order to reduce NOx emissions at high load conditions. With this concept, the premixed combustion occurs under the fuel lean conditions and the diffusion combustion occurs under the high temperature conditions. As seen in the result of combustion observation, a first stage combustion occurs with no luminous flame. A second stage combustion occurs with a luminous flame after very short ignition delay period. However the luminous flame is disappeared immediately. Because cylinder temperature is high, and hence soot oxidizes immediately. 5 refs., 11 figs., 1 tab.

  7. Discursos sobre comportamento de risco à saúde e a moralização da vida cotidiana Discourses about health risk behaviour and the moralization of the everyday life

    Directory of Open Access Journals (Sweden)

    Marcos Bagrichevsky

    2010-06-01

    Full Text Available O texto aborda criticamente a polaridade entre discursos sobre estilos de vida saudáveis e sedentarismo no contexto dos novos recursos tecnológicos de busca e disseminação de informações em saúde. Argumenta-se que a racionalidade tecnocientífica contemporânea fez emergir uma "economia das verdades" que, na perspectiva de conduzir a estilos de vida seguros, tem prescrito um ideário normativo de autodisciplina gerador de angústias e de consumo de artefatos agenciadores de gastos calóricos. Na produção hegemônica desses regimes de verdade, o sedentarismo se apresenta como conduta de risco à saúde, equivalendo à falência moral e inaceitável falta de cuidado consigo. Enfatiza-se que a profusão de discursos sobre estilos de vida e risco, tomados como dispositivos biopolíticos imbricados nos processos comunicacionais em saúde, merece foco por suas implicações éticas e políticas. A espetacularização de modos de vida associados ao consumo e a produção de narrativas que influenciam perversamente nossa cultura têm nos distanciado de uma noção de saúde socialmente possível. Discute-se, enfim, a essência reguladora de tais referentes simbólicos na construção de sistemas de conhecimento que vêm (redefinindo o que é ser saudável, normal, doente.The text analyses critically the polarity between discourses about healthy life styles and the sedentariness in the context of new technologies for health information research and dissemination. We argue that the techno-scientific rationality has grown an 'economy of trues' which, on the perspective of conducting to safe life styles, has prescribed a normative ideal of self discipline which tends to generate distress and consumerism of artifacts of burning calories. In the hegemonic production of systems of truth, sedentariness has been seen as a kind of unhealthy behavior that is ranked as moral failure. Emphasis is given about the multiple discourses embracing life styles and

  8. 76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

    Science.gov (United States)

    2011-03-24

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc.), Collectible Concepts Group, Inc., Communitronics of... is a lack of current and accurate information concerning the securities of Clean Energy Combustion...

  9. Effect of combustion characteristics on wall radiative heat flux in a 100 MWe oxy-coal combustion plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.; Ryu, C. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Chae, T.Y. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Yang, W. [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Kim, Y.; Lee, S.; Seo, S. [Korea Electric Power Research Institute (KEPRI), Daejeon (Korea, Republic of). Power Generation Lab.

    2013-07-01

    Oxy-coal combustion exhibits different reaction, flow and heat transfer characteristics from air-coal combustion due to different properties of oxidizer and flue gas composition. This study investigated the wall radiative heat flux (WRHF) of air- and oxy-coal combustion in a simple hexahedral furnace and in a 100 MWe single-wall-fired boiler using computational modeling. The hexahedral furnace had similar operation conditions with the boiler, but the coal combustion was ignored by prescribing the gas properties after complete combustion at the inlet. The concentrations of O{sub 2} in the oxidizers ranging between 26 and 30% and different flue gas recirculation (FGR) methods were considered in the furnace. In the hexahedral furnace, the oxy-coal case with 28% of O{sub 2} and wet FGR had a similar value of T{sub af} with the air-coal combustion case, but its WRHF was 12% higher. The mixed FGR case with about 27% O{sub 2} in the oxidizer exhibited the WRHF similar to the air-coal case. During the actual combustion in the 100 MWe boiler using mixed FGR, the reduced volumetric flow rates in the oxy-coal cases lowered the swirl strength of the burners. This stretched the flames and moved the high temperature region farther to the downstream. Due to this reason, the case with 30% O{sub 2} in the oxidizers achieved a WRHF close to that of air-coal combustion, although its adiabatic flame temperature (T{sub af}) and WHRF predicted in the simplified hexahedral furnace was 103 K and 10% higher, respectively. Therefore, the combustion characteristics and temperature distribution significantly influences the WRHF, which should be assessed to determine the ideal operating conditions of oxy- coal combustion. The choice of the weighted sum of gray gases model (WSGGM) was not critical in the large coal-fired boiler.

  10. Infrared monitoring of combustion

    International Nuclear Information System (INIS)

    Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

    1991-01-01

    In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

  11. Control device for combustible gas concentration

    International Nuclear Information System (INIS)

    Osawa, Yasuo.

    1988-01-01

    Purpose: To control the concentration of combustible gases such as hydrogen evolved in a reactor container upon loss-of-coolant accidents. Constitution: Combustible gases evolved from the lower area of a drywell in which a combustible atmosphere is liable to be formed locally are taken out through a take-out pipeway to the outside of a reactor container and processed by a hydrogen-oxygen recombiner. Combustible gases in other areas of the drywell are also introduced to the lower area of the drywell and then taken-out externally for procession. Further, combustible gases in the suppression chamber are introduced by the opening of a vacuum breaking valve through a gas supply pipe to the lower area of the drywell and fluids in the drywell are stirred and diluted with fluids exhausted from the gas supply pipe. Disposition of such take-out pipeway and gas supply pipe can reduce the possibility of forming local combustible atmosphere to improve the integrity of the reactor container. (Kamimura, M.)

  12. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.

    2006-11-01

    Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

  13. PDF Modeling of Turbulent Combustion

    National Research Council Canada - National Science Library

    Pope, Stephen B

    2006-01-01

    .... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

  14. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

  15. In situ high-temperature gas sensors: continuous monitoring of the combustion quality of different wood combustion systems and optimization of combustion process

    Directory of Open Access Journals (Sweden)

    H. Kohler

    2018-03-01

    Full Text Available The sensing characteristics and long-term stability of different kinds of CO ∕ HC gas sensors (non-Nernstian mixed potential type during in situ operation in flue gas from different types of low-power combustion systems (wood-log- and wood-chip-fuelled were investigated. The sensors showed representative but individual sensing behaviour with respect to characteristically varying flue gas composition over the combustion process. The long-term sensor signal stability evaluated by repeated exposure to CO ∕ H2 ∕ N2 ∕ synthetic air mixtures showed no sensitivity loss after operation in the flue gas. Particularly for one of the sensors (Heraeus GmbH, this high signal stability was observed in a field test experiment even during continuous operation in the flue gas of the wood-chip firing system over 4 months. Furthermore, it was experimentally shown that the signals of these CO ∕ HC sensing elements yield important additional information about the wood combustion process. This was demonstrated by the adaptation of an advanced combustion airstream control algorithm on a wood-log-fed fireplace and by the development of a combustion quality monitoring system for wood-chip-fed central heaters.

  16. HABERMAS AND THE QUESTION OF THE COGNITIVE VALIDITY OF MORAL AND THEORETICAL STATEMENTS HABERMAS E A QUESTÃO DA VALIDADE COGNITIVA DOS ENUNCIADOS TEÓRICOS E MORAIS

    Directory of Open Access Journals (Sweden)

    Antonio Saturnino Braga

    2010-10-01

    Full Text Available A cognitivist and discursive ethics must distinguish itself from two other metaethical positions: on one side, a cognitivist but non-discursive ethics; on the other side, a noncognitivist but communicative, argumentative and procedural ethics. The aim of the present work is to use Habermas’ reflections on the topic of truth to develop an ideal-typical scheme which could be helpful in explaining those distinctions. This scheme will contain three typical conceptions about the truth of theoretical statements: realist-intuitionist conception, objectivist-semantic conception and discursive-consensual conception. The distinctiveness of the cognitive-discursive ethics will then be explained by relating the cognitivist but non-discursive ethics and the noncognitivist but procedural ethics to their respective conceptions of truth: the realist-intuitionist conception and the objectivist-semantic conception.Uma ética cognitivista discursiva precisa se diferençar de duas outras posições metaéticas: por um lado, uma ética cognitivista mas não-discursiva; por outro lado, uma ética anticognitivista mas comunicativa, argumentativa e procedimental. O objetivo do presente trabalho é aproveitar as reflexões de Habermas sobre o tema da verdade para elaborar um esquema ideal-típico que possa ajudar no esclarecimento dessas diferenças. Este esquema conterá três posições típicas sobre a verdade dos enunciados téoricos: concepção realista-intuicionista, concepção objetivista-semântica e concepção discursivo-consensual. A especificidade da ética cognitivista discursiva será então esclarecida correlacionando-se a ética cognitivista não-discursiva e a ética anticognitivista procedimental às suas respectivas concepções da verdade: concepção realista-intuicionista e concepção objetivista-semântica.

  17. Internal and surface phenomena in metal combustion

    Science.gov (United States)

    Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

    1995-01-01

    Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

  18. Second law comparison of oxy-fuel combustion and post-combustion carbon dioxide separation

    International Nuclear Information System (INIS)

    Simpson, Adam P.; Simon, A.J.

    2007-01-01

    To define 2nd law efficiency targets for novel separation technologies, a simplified model of a power plant with two forms of CO 2 capture was developed. In this investigation, oxy-fuel combustion and post-combustion CO 2 separation were compared on an exergetic basis. Using exergy balances and black-box models of power plant components, multiple scenarios were run to determine the impact of plant configuration and separation unit efficiency on overall plant performance. Second law efficiency values from the literature were used to set the baseline performance of various CO 2 separation configurations. Assumed advances in 2nd law efficiency were used to determine the potential for overall system performance improvement. It was found that the 2nd law efficiency of air separation must reach a critical value before the thermodynamics of oxy-fuel combustion become favorable. Changes in operating equivalence ratio significantly move the tipping-point between post-combustion and oxy-fuel strategies

  19. Investigating co-combustion characteristics of bamboo and wood.

    Science.gov (United States)

    Liang, Fang; Wang, Ruijuan; Jiang, Changle; Yang, Xiaomeng; Zhang, Tao; Hu, Wanhe; Mi, Bingbing; Liu, Zhijia

    2017-11-01

    To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. New technologies reducing emissions from combustion of biofuels

    International Nuclear Information System (INIS)

    Oravainen, H.

    1997-01-01

    In reducing CO 2 emissions, bioenergy will be the most important source of renewable energy in the next few decades. In principle, combustion of biomass is friendly to the environment because CO 2 released during combustion is recycled back into natural circulation. Biofuels normally contain little nitrogen and sulphur. However, depending on the combustion technology used, emissions may be quite high. This is true of combustion of biomass fuels in small appliances like wood stoves, fireplaces, small boilers etc. When fuels having high content of volatile matter are burnt in appliances using batch type combustion, the process is rather an unsteady-state combustion. Emissions of carbon monoxide, other combustible gases and particulates are quite difficult to avoid. With continuous combustion processes this is not normally a problem. This conference paper presents some means of reducing emissions from combustion of biofuels. 5 refs., 4 figs

  1. Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

    Science.gov (United States)

    Guo, Feihong; Zhong, Zhaoping

    2018-08-01

    This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

    KAUST Repository

    Vallinayagam, R.

    2018-03-20

    The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

  3. Comparison of different chemical kinetic mechanisms of methane combustion in an internal combustion engine configuration

    OpenAIRE

    Ennetta Ridha; Hamdi Mohamed; Said Rachid

    2008-01-01

    Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion...

  4. Alergia alimentaria

    OpenAIRE

    Botero Osorio, Verónica; Serrano Reyes, Carlos Daniel; Fundación Valle de Lili

    2008-01-01

    Alergia alimentaria/ ¿Cómo se produce la alergia alimentaria?/ ¿Cuáles son los factores de riesgo?/ ¿Cómo se manifiesta la alergia alimentaria?/ ¿Cuáles son los alimentos que producen alergias con mayor frecuencia?/ ¿Cómo se hace un diagnostico correcto de la alergia alimentaria?/ ¿Cómo se trata la alergia alimentaria?/ ¿Es posible prevenir las alergias alimentarias?/ Pronostico/ Mitos y verdades sobre la alergia alimentaria

  5. El proceso de sanación de la sociedad ecuatoriana: una mirada desde la Justicia Transicional: entrevista a Romel Jurado Vargas.

    OpenAIRE

    Landaburo Sánchez, Liosday

    2015-01-01

    La justicia transicional implica arrojar verdad sobre los hechos graves de violaciones de los derechos humanos, arrojar luz, conocimiento, poder identificar a las víctimas que muchas veces son invisibilizadas, ocultadas, incluso culpabilizadas de los hechos que sufrieron. El proceso de justicia transicional implica establecer procesos de sanción a los responsables; no solo identificarlos, sino establecer sanciones de acuerdo con el Estado de Derecho y de acuerdo con los instrumentos intern...

  6. ¡Son notables… los desaciertos y los vacíos!

    Directory of Open Access Journals (Sweden)

    Manuel Argüello Rodríguez

    2007-10-01

    Full Text Available Son notables las ausencias y los equilibrios forzados en el informe de los cinco ciudadanos costarricenses sobre el TLC. Ausencias y seudoequilibrios que han sido ya utilizados para fortalecer la campaña de propaganda arrebatadora contra la oposición al TLC indicando que ‘los notables’ desnudaron los fantasmas (con lo cual, a decir verdad no se vería nada, sería la total transparencia.

  7. Burning Questions in Gravity-Dependent Combustion Science

    Science.gov (United States)

    Urban, David; Chiaramonte, Francis P.

    2012-01-01

    Building upon a long history of spaceflight and ground based research, NASA's Combustion Science program has accumulated a significant body of accomplishments on the ISS. Historically, NASAs low-gravity combustion research program has sought: to provide a more complete understanding of the fundamental controlling processes in combustion by identifying simpler one-dimensional systems to eliminate the complex interactions between the buoyant flow and the energy feedback to the reaction zone to provide realistic simulation of the fire risk in manned spacecraft and to enable practical simulation of the gravitational environment experienced by reacting systems in future spacecraft. Over the past two decades, low-gravity combustion research has focused primarily on increasing our understanding of fundamental combustion processes (e.g. droplet combustion, soot, flame spread, smoldering, and gas-jet flames). This research program was highly successful and was aided by synergistic programs in Europe and in Japan. Overall improvements were made in our ability to model droplet combustion in spray combustors (e.g. jet engines), predict flame spread, predict soot production, and detect and prevent spacecraft fires. These results provided a unique dataset that supports both an active research discipline and also spacecraft fire safety for current and future spacecraft. These experiments have been conducted using the Combustion Integrated Rack (CIR), the Microgravity Science Glovebox and the Express Rack. In this paper, we provide an overview of the earlier space shuttle experiments, the recent ISS combustion experiments in addition to the studies planned for the future. Experiments in combustion include topics such as droplet combustion, gaseous diffusion flames, solid fuels, premixed flame studies, fire safety, and super critical oxidation processes.

  8. Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2011-04-15

    The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

  9. Catalytically enhanced combustion process

    International Nuclear Information System (INIS)

    Rodriguez, C.

    1992-01-01

    This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

  10. Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

    International Nuclear Information System (INIS)

    Chen, Zheng; Yang, Feng; Xue, Shuo; Wu, Zhenkuo; Liu, Jingping

    2015-01-01

    Highlights: • Effects of 0–50% n-butanol addition on GDI engine are experimentally studied. • Higher n-butanol fractions increase combustion pressure and fasten burning rate. • Higher n-butanol fractions increase BSFC but improve BTE. • Higher n-butanol fractions enhance combustion stability but increase knock intensity. • Higher n-butanol fractions reduce exhaust temperature and NOx emissions. - Abstract: An experimental study was carried out on a turbocharged gasoline direct injection (GDI) engine fueled by n-butanol/gasoline blends. Effects of n-butanol percents (15%, 30%, and 50%) on combustion and performance of the engine operating on stoichiometric combustion condition were discussed and also compared with pure gasoline in this paper. The results indicate that n-butanol/gasoline blends increase combustion pressure and pressure rise rate, fasten burning rate, and shorten ignition delay and combustion duration, as compared to pure gasoline. Moreover, these trends are impacted more evidently with increased n-butanol fraction in the blends. In addition, higher n-butanol percent of gasoline blends increase combustion temperature but decrease the temperature in the later stage of expansion stroke, which contributes to the control of exhaust temperature at high-load. With regards to engine performance, higher n-butanol percent in the blends results in increased brake specific fuel consumption (BSFC) and higher brake thermal efficiency (BTE). However, higher n-butanol addition helps to improve combustion stability but shows slightly higher knock possibility in high-load. In that case, the knock trend could be weakened by retarding ignition timing. Moreover, higher n-butanol addition significantly decreases NOx emissions, but it increases CO emissions obviously.

  11. Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei; Roberts, William L.; Fang, Tiegang

    2015-01-01

    This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2

  12. Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

    International Nuclear Information System (INIS)

    Bělohradský, Petr; Skryja, Pavel; Hudák, Igor

    2014-01-01

    This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NO x type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NO x ) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NO x emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NO x emission was below 120 mg/Nm 3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO 2 and H 2 O. The available heat at 46% O 2 was higher by 20% compared with that at 21% O 2 . - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NO x increased sharply as oxygen concentration increased during PE tests. • NO x was below 120 mg/Nm 3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O 2 concentration was increased. • OEC flames were observed stable, more luminous and

  13. Combustion modeling in waste tanks

    International Nuclear Information System (INIS)

    Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

    1997-01-01

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

  14. Ignition and wave processes in combustion of solids

    CERN Document Server

    Rubtsov, Nickolai M; Alymov, Michail I

    2017-01-01

    This book focuses on the application of classical combustion theory to ignition and flame propagation in solid-solid and gas-solid systems. It presents experimental investigations in the areas of local ignition, filtration combustion, self-propagating high temperature synthesis and nanopowders protection. The authors highlight analytical formulas used in different areas of combustion in solids and propose an approach based on classical combustion theory. The book attempts to analyze the basic approaches to understanding of solid-solid and solid - gas combustion presented in contemporary literature in a unified approach based on classical combustion theory. .

  15. Effects of stepwise gas combustion on NOx generation

    International Nuclear Information System (INIS)

    Woperane Seredi, A.; Szepesi, E.

    1999-01-01

    To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

  16. Fuel Combustion and Engine Performance | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

  17. Specifics of phytomass combustion in small experimental device

    Science.gov (United States)

    Lenhard, Richard; Mičieta, Jozef; Jandačka, Jozef; Gavlas, Stanislav

    2015-05-01

    A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass), which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  18. Specifics of phytomass combustion in small experimental device

    Directory of Open Access Journals (Sweden)

    Lenhard Richard

    2015-01-01

    Full Text Available A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass, which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  19. Traveling-Wave Thermoacoustic Engines With Internal Combustion

    Science.gov (United States)

    Weiland, Nathan Thomas; Zinn, Ben T.; Swift, Gregory William

    2004-05-11

    Thermoacoustic devices are disclosed wherein, for some embodiments, a combustion zone provides heat to a regenerator using a mean flow of compressible fluid. In other embodiments, burning of a combustible mixture within the combustion zone is pulsed in phase with the acoustic pressure oscillations to increase acoustic power output. In an example embodiment, the combustion zone and the regenerator are thermally insulated from other components within the thermoacoustic device.

  20. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

    Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

  1. The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

    Science.gov (United States)

    Dickey, Daniel W.; Vinyard, Shannon; Keribar, Rifat

    1988-01-01

    The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide emissions. The unburned hydrocarbon emissions were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine.

  2. Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

    NARCIS (Netherlands)

    Leskens, M.

    2013-01-01

    The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

  3. Toxicology of Biodiesel Combustion products

    Science.gov (United States)

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  4. Analítica e ontologia: sobre a teoria kantiana dos objetos [Analytic and ontology: on the Kantian theory of objects

    Directory of Open Access Journals (Sweden)

    Juan Adolfo Bonaccini

    2016-09-01

    Full Text Available No presente estudo defende-se uma interpretação "ontológica" da Crítica da razão pura. Especificamente, argumenta-se que a Analítica Transcendental apresenta uma "teoria dos objetos", a saber, uma teoria categorial que opera uma reconstrução meta-teórica da estrutura objetiva do nosso pensamento e da experiência do mundo a partir de uma reflexão sobre a estrutura formal de nossas faculdades cognitivas. Assim, em face de concepções que reduzem as categorias a meras funções lógicas, ou a condições epistêmicas, ou semânticas, argumenta-se que na verdade Kant as considera primordialmente como predicados ontológicos, na medida em que constituem a priori a estrutura da "objetualidade" das coisas, tornando possível pensar os "objetos" que compõem o inventário do mundo que podemos pensar e conhecer. Defende-se também que a epistemologia e a semântica estão contidas no projeto kantiano, mas pressupõem uma ontologia crítica enquanto meta-teoria dos objetos: dos "objetos" que só podemos pensar em geral; dos "objetos" que podemos pensar e também conhecer; e, finalmente, dos objetos que somente podemos pensar mediante predicados transcendentais, mas não podemos conhecer.

  5. Producer for vegetal combustibles for internal-combustion motors

    Energy Technology Data Exchange (ETDEWEB)

    1943-12-28

    A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

  6. Characterization of gold and nickel coating on AISI 304 stainless steel for use in the fabrication of current collector plates for fuel cells; Caracterizacion de recubrimientos de oro y niquel realizados sobre acero inoxidable AISI 304 para su empleo en la fabricacion de placas colectoras de corriente para celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Aguilar Gama, M. Tulio [UNAM. Facultad de Quimica, Mexico D.F. (Mexico); Cano Castillo, Ulises; Albarran, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Olvera, J. Carlos; Orozco, German [CIDETEQ, Pedro Escobedo, Queretaro (Mexico)

    2009-09-15

    Among the different components that compose fuel cell technology (MEA, bipolar plates, seals, etc.) current collector plates play an important role in the good performance of fuel cells, since they collect all of the current generated and distribute it to the external circuit. Therefore, the most important properties that the current collector plates should have are excellent conductivity and good resistance to the corrosive conditions present in the fuel cell. This document presents results obtained during the nickel and gold electrodeposition process on AISI 304 stainless steel and the morphology and thickness of each coating, their adhesion, hardness and conductivity values. Finally, results obtained during some of the electrochemical tests performed on the coatings are shown. [Spanish] De los diferentes componentes que integran la tecnologia de celdas de combustible (MEA's, placas bipolares, sellos, etc.), las placas colectoras de corriente tienen un importante rol en el buen desempeno de la celdas de combustibles, ya que en estas placas se colecta toda la corriente generada y se distribuye al circuito externo. Debido a esto, las propiedades mas importantes que deben tener las placas colectaras de corriente son: excelente conductividad y buena resistencia a las condiciones corrosivas presentes en la celda de combustible. En este documento se presentan los resultados obtenidos en el proceso de electrodeposicion de niquel y oro sobre acero inoxidable AISI 304, asi como la morfologia y el espesor de cada recubrimiento, sus valores de adherencia, dureza y conductividad. Finalmente se muestran tambien los resultados obtenidos de algunas pruebas electroquimicas a los que fueron sometidos los recubrimientos.

  7. Investigation of bluff-body micro-flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • The temperature uniformity of the micro-flameless combustion increases when a triangular bluff-body is applied. • The velocity and temperature of exhaust gases are higher in micro-flameless combustion compared to the conventional mode. • The rate of fuel–oxidizer consumption in micro-flameless mode is lower than conventional micro-combustion. - Abstract: Characteristics of lean premixed conventional micro-combustion and lean non-premixed flameless regime of methane/air are investigated in this paper by solving three-dimensional governing equations. At moderate equivalence ratio (∅ = 0.5), standard k–ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models. The effect of bluff-body on the temperature distribution of both conventional and flameless mode is developed. The results show that in the premixed conventional micro-combustion the stability of the flame is increased when a triangular bluff-body is applied. Moreover, micro-flameless combustion is more stable when bluff-body is used. Micro-flameless mode with bluff-body and 7% O 2 concentration (when N 2 is used as diluent) illustrated better performance than other cases. The maximum temperature in premixed conventional micro-combustion and micro-flameless combustion was recorded 2200 K and 1520 K respectively. Indeed, the flue gas temperature of conventional mode and flameless combustion was 1300 K and 1500 K respectively. The fluctuation of temperature in the conventional micro-combustor wall has negative effects on the combustor and reduces the lifetime of micro-combustor. However, in the micro-flameless mode, the wall temperature is moderate and uniform. The rate of fuel–oxidizer consumption in micro-flameless mode takes longer time and the period of cylinders recharging is prolonged

  8. Ciento cincuenta años de combustión de hidrocarburos fósiles: las alternativas emergentes One hundred and fyfty years of combustion of fossil hydrocarbons: the emergent alternatives

    Directory of Open Access Journals (Sweden)

    Jorge Laine

    2009-12-01

    Full Text Available Luego de ciento cincuenta años de haberse perforado los primeros pozos comerciales de petróleo que condujeron al uso intensivo de combustibles líquidos para mover los vehículos de transporte, se está arribando al pico de las reservas de petróleo del planeta. Queda aún una buena porción por gastar, con la expectativa de que las consecuencias sean mejores que en la primera parte, la cual ha implicado varias guerras y deterioros del ambiente. Este ensayo aporta un resumen sobre la historia de los combustibles fósiles y sobre la prospectiva de las alternativas energéticas emergentes, poniendo énfasis en la bioenergía como una alternativa para la transición entre la actual era de la combustión y la nueva era de la energía limpia.After one hundred fifty years of drilling first commercial petroleum wells that led to the intensive use of liquid fuels to move transport vehicles, we are arriving at the peak of the world-wide petroleum reserves. Yet, we still have a good portion for spending, with the hope that the consequences will be better than in the first part, which has implied several wars and deteriorations of the environment. This assay brings a review about the history of fossil fuels and with the prospective of the emergent energetic alternatives, placing emphasis on bioenergy as an alternative for the transition between the actual combustion age and the new age of clean energy.

  9. Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines

    International Nuclear Information System (INIS)

    Su, LiWang; Li, XiangRong; Zhang, Zheng; Liu, FuShui

    2014-01-01

    Highlights: • A new combustion system named FSCS for DI diesel engines was proposed. • Fuel/air mixture formation was improved for the application of FSCS. • The FSCS showed a good performance on emission characteristics. - Abstract: To optimize the fuel/air mixture formation and improve the environmental effect of direct injection (DI) diesel engines, a new forced swirl combustion system (FSCS) was proposed concerned on unique design of the geometric shape of the combustion chamber. Numerical simulation was conducted to verify the combustion and emission characteristics of the engines with FSCS. The fuel/air diffusion, in-cylinder velocity distribution, turbulent kinetic energy and in-cylinder temperature distribution were analyzed and the results shown that the FSCS can increase the area of fuel/air diffusion and improve the combustion. The diesel engine with FSCS also shown excellent performance on emission. At full load condition, the soot emission was significantly reduced for the improved fuel/air mixture formation. There are slightly difference for the soot and NO emission between the FSCS and the traditional omega combustion system at lower load for the short penetration of the fuel spray

  10. Combustion & Laser Diagnostics Research Complex (CLDRC)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

  11. Alguns Rodrigos: relato de viagem sobre a ficcionalização do sujeito

    Directory of Open Access Journals (Sweden)

    Rodrigo Barbosa

    2017-12-01

    Full Text Available Este trabalho investiga as fronteiras e interpenetrações entre a ficção e o real (entre verdade e mentira nas narrativas de si. Observa a distinção aristotélica entre cronistas e poetas; a “literariedade condicional” de textos referenciais e a “literariedade constitutiva” de textos ficcionais, conforme Genette; a divisão de Cosson entre “império dos fatos” e “jardim da imaginação”. Analisa a quebra desta dicotomia pela recepção literária de textos autobiográficos e a provocação trazida pelo conceito de autoficção. Avalia a frequente experiência romanesca contemporânea de transitar entre realidade e invenção. Para análise de textos por este prisma, propõe a ideia de uma “linha da ficcionalidade” e discute os romances Tentativas de capturar o ar, de Flávio Izhaki; Baseado em fatos reais, de Delphine de Vigan; A resistência, de Julián Fuks. Questões sobre a ficcionalização do sujeito, em suas narrativas de vida, são abordadas: a autoficcionalização no cumprimento de seus papéis sociais; a ação do inconsciente nas escolhas narrativas; a invenção da memória. São referenciados autores como Aristóteles, Roland Barthes, Philippe Lejeune, Serge Doubrovski, Mikhail Bakhtin, Gérard Genette, Philippe Gasparini, Silviano Santiago, Eurídice Figueiredo, Evando Nascimento, Manuel Alberca, Anna Faedrich, Rildo Cosson.   --- DOI: http://dx.doi.org/10.12957/matraga.2017.30066

  12. The rheodynamics and combustion of coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Burdukov, A.P.; Popov, V.I.; Tomilov, V.G.; Fedosenko, V.D. [Russian Academy of Science, Novosibirsk (Russian Federation). Inst. of Thermophysics (Siberian Branch, Russian Academy of Science)

    2002-05-01

    Investigation methods for characteristics of movement along the tubes, combustion dynamics and gasification of separate drops were developed for the coal-water mixtures (CWM). The following parameters were determined on the basis of laser heating: thermometric, pyrometric and concentration dynamics of single-drop combustion, complete combustion times, duration of temperature phases of combustion, as well as the moment and temperature of ignition. Information on the combustion mass velocity and gasification products was also obtained using laser heating. 6 refs., 13 figs., 1 tab.

  13. Bifurcation, pattern formation and chaos in combustion

    International Nuclear Information System (INIS)

    Bayliss, A.; Matkowsky, B.J.

    1991-01-01

    In this paper problems in gaseous combustion and in gasless condensed phase combustion are studied both analytically and numerically. In gaseous combustion we consider the problem of a flame stabilized on a line source of fuel. The authors find both stationary and pulsating axisymmetric solutions as well as stationary and pulsating cellular solutions. The pulsating cellular solutions take the form of either traveling waves or standing waves. Transitions between these patterns occur as parameters related to the curvature of the flame front and the Lewis number are varied. In gasless condensed phase combustion both planar and nonplanar problems are studied. For planar condensed phase combustion we consider two models: accounts for melting and does not. Both models are shown to exhibit a transition from uniformly to pulsating propagating combustion when a parameter related to the activation energy is increased. Upon further increasing this parameter both models undergo a transition to chaos: by intermittency and by a period doubling sequence. In nonplanar condensed phase combustion the nonlinear development of a branch of standing wave solutions is studied and is shown to lead to relaxation oscillations and subsequently to a transition to quasi-periodicity

  14. Fundamentals of Turbulent and Multi-Phase Combustion

    CERN Document Server

    Kuo, Kenneth Kuan-yun

    2012-01-01

    Detailed coverage of advanced combustion topics from the author of Principles of Combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form-until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence

  15. An Assessment of Combustion Dynamics in a Low-Nox, Second-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

    Science.gov (United States)

    Tacina, K. M.; Chang, C. T.; Lee, P.; Mongia, H.; Podboy, D. P.; Dam, B.

    2015-01-01

    Dynamic pressure measurements were taken during flame-tube emissions testing of three second-generation swirl-venturi lean direct injection (SV-LDI) combustor configurations. These measurements show that combustion dynamics were typically small. However, a small number of points showed high combustion dynamics, with peak-to-peak dynamic pressure fluctuations above 0.5 psi. High combustion dynamics occurred at low inlet temperatures in all three SV-LDI configurations, so combustion dynamics were explored further at low temperature conditions. A point with greater than 1.5 psi peak-to-peak dynamic pressure fluctuations was identified at an inlet temperature of 450!F, a pressure of 100 psia, an air pressure drop of 3%, and an overall equivalence ratio of 0.35. This is an off design condition: the temperature and pressure are typical of 7% power conditions, but the equivalence ratio is high. At this condition, the combustion dynamics depended strongly on the fuel staging. Combustion dynamics could be reduced significantly without changing the overall equivalence ratio by shifting the fuel distribution between stages. Shifting the fuel distribution also decreased NOx emissions.

  16. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  17. Regarding the Modern Virtue of Considering the Common good over one’s own Interests: Dreams and other Literary Devices in «Los paseos de la verdad» by Fernández de Lizardi

    Directory of Open Access Journals (Sweden)

    M.ª Isabel TERÁN ELIZONDO

    2011-01-01

    Full Text Available His article studies the presence of dreams as a recurring narrative element in the work of Fernández de Lizardi, and in particular in Los paseos de la verdad, published in five excerpts in 1815 in the Alacena de Frioleras, in imitation of the Sueños of torres Villarroel. Emphasis is placed on the moralizing intention of the author and the linking of dreams to the constitution of an ideal that of a new nation built upon a synthesis of the best ideas of the age, be they traditional or modern.

  18. O que há de real e de irreal com o realismo: Searle versus Rorty What there is of real and unreal in Realism: Searle versus Rorty

    Directory of Open Access Journals (Sweden)

    Paulo Ghiraldelli Júnior

    1999-01-01

    Full Text Available O texto fala a respeito do debate entre Searle e Rorty sobre "irracionalismo" de Rorty. Ele tenta mostrar que a posição de Rorty está fora do campo "realismo versus anti-realismo" e o "irracionalismo" não é um bom adjetivo. Searle estaria sobre uma linha incorreta em sua abordagem do tema da verdade em Rorty.The article talks about debate between Searle and Rorty on a "irrationalism" of Rorty. The text tries to show that the Rorty's position is out of the field "Realism versus Anti Realism" and the "irracionalism" is not a good adjective. Searle would be on a incorrect line in his account of the Rorty's theme of truth.

  19. Flow and Combustion in Advanced Gas Turbine Combustors

    CERN Document Server

    Janicka, Johannes; Schäfer, Michael; Heeger, Christof

    2013-01-01

    With regard to both the environmental sustainability and operating efficiency demands, modern combustion research has to face two main objectives, the optimization of combustion efficiency and the reduction of pollutants. This book reports on the combustion research activities carried out within the Collaborative Research Center (SFB) 568 “Flow and Combustion in Future Gas Turbine Combustion Chambers” funded by the German Research Foundation (DFG). This aimed at designing a completely integrated modeling and numerical simulation of the occurring very complex, coupled and interacting physico-chemical processes, such as turbulent heat and mass transport, single or multi-phase flows phenomena, chemical reactions/combustion and radiation, able to support the development of advanced gas turbine chamber concepts.

  20. Reducing emissions from diesel combustion

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper contains information dealing with engine design to reduce emissions and improve or maintain fuel economy. Topics include: Observation of High Pressure Fuel Spray with Laser Light Sheet Method; Determination of Engine Cylinder Pressures from Crankshaft Speed Fluctuations; Combustion Similarity for Different Size Diesel Engines: Theoretical Prediction and Experimental Results; Prediction of Diesel Engine Particulate Emission During Transient Cycles; Characteristics and Combustibility of Particulate Matter; Dual-Fuel Diesel Engine Using Butane; Measurement of Flame Temperature Distribution in D.I. Diesel Engine with High Pressure Fuel Injection: and Combustion in a Small DI Diesel Engine at Starting

  1. Mechanisms and characteristics of silicon combustion in nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mukasian, A.S.; Martynenko, V.M.; Merzhanov, A.G.; Borovinskaia, I.P.; Blinov, M.IU.

    1986-10-01

    An experimental study is made of the principal characteristics of combustion in the system silicon-nitrogen associated with phase transitions of the first kind (silicon melting and silicon nitride dissociation). Concepts of the combustion mechanism are developed on the basis of elementary models of combustion of the second kind and filtering combustion theory. In particular, it is shown that, in the pressure range studied (10-20 MPa), filtering does not limit the combustion process. Details of the experimental procedure and results are presented. 22 references.

  2. Review of Membrane Oxygen Enrichment for Efficient Combustion

    Science.gov (United States)

    Ariono, Danu; Kusuma Wardani, Anita

    2017-07-01

    Oxygen enrichment from air is a simple way of increasing the efficiency of combustion process, as in oxy-combustion. Oxy-combustion has become one of the most attracting combustion technologies because of its potential to address both pollutant reduction and CO2 capture. In oxy-combustion, the fuel and recycled flue gas are combusted with oxygen enriched air (OEA). By using OEA, many benefits can be obtained, such as increasing available heat, improving ignition characteristics, flue gas reduction, increasing productivity, energy efficiency, turndown ratio, and flame stability. Membrane-based gas separation for OEA production becomes an attractive technology over the conventional technology due to the some advantages, including low capital cost, low energy consumption, compact size, and modularity. A single pass through membrane usually can enrich O2 concentration in the air up to 35% and a 50% concentration can be achieved with a double pass of membrane. The use of OEA in the combustion process eliminates the presence of nitrogen in the flue gas. Hence, the flue gas is mainly composed of CO2 and condensable water that can be easily separated. This paper gives an overview of oxy-combustion with membrane technology for oxygen enrichment process. Special attention is given to OEA production and the effect of OEA to the efficiency of combustion.

  3. 14 CFR 25.833 - Combustion heating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heating systems. 25.833 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.833 Combustion heating systems. Combustion heaters must be approved. [Amdt. 25-72, 55 FR 29783, July 20, 1990...

  4. Chemistry and radiation in oxy-fuel combustion

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2011-01-01

    In order to investigate the role of combustion chemistry and radiation heat transfer in oxy-fuel combustion modeling, a computational fluid dynamics (CFD) modeling study has been performed for two different oxy-fuel furnaces. One is a lab-scale 0.8MW oxy-natural gas flame furnace whose detailed in....... Among the key issues in combustion modeling, e.g., mixing, radiation and chemistry, this paper derives useful guidelines on radiation and chemistry implementation for reliable CFD analyses of oxy-fuel combustion, particularly for industrial applications....

  5. Verdad absoluta desde el libro del Éxodo: el nombre divino

    Directory of Open Access Journals (Sweden)

    Andrés Ferrada Moreira

    2008-01-01

    Full Text Available Este artículo pretende iluminar el significado del nombre divino 'ehyé 'aser 'ehyé (Seré el que seré; Ex 3, 14, para ejemplarizar en qué sentido el libro del Éxodo (y tal vez el grueso del Antiguo Testamento afirma algunas verdades con pretensión de absoluto. Para el lector de nuestros tiempos, Seré el que seré resulta problemático, no solo por su formulación enigmática, cuyo sentido no entiende a cabalidad; sino también porque culturalmente pierden valor, cada vez con mayor fuerza, las proposiciones que se postulan como absolutas. La interpretación existencial del nombre de Dios, que se propone, resuelve el enigma: Seré el que seré designa el compromiso divino injustificado de su presencia a favor de su pueblo. El sentido absoluto de esta afirmación coincide con el de otras importantes afirmaciones teológicas del libro del Éxodo: no pretenden anular la esfera histórica de la existencia, particularmente la libertad humana y su contingencia, sino al contrario muestran su valor y le aportan su fundamento de origen, sentido y dirección.The author of thiis article intends to provide insight into the meaning of the divine ñame 'ehyé 'áser 'ehyé (I will be whom will be; Ex 3,14, in order to exemplify in what sense the book of Exodus (and, perhaps, the greater part of the Oíd Testament affirms certain truths with the intention of absoluteness. For the reader of our own times, I will be whom I will be turns out to be problematic, not only for its enigmatic formation, whose meaning is not fully captured, but also because, culturally, the propositions formulated as absolutes lose in an ever greater degree their valué. The existential interpretation of the ñame of God, which the author proposes, resolves the enigma: I will be whom will be designates the unjustified divine commitment of His presence in favor of His people. The absolute sense of this affirmation coincides with that of other important theological affirmations of

  6. FY 1994 annual report. Advanced combustion science utilizing microgravity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    Researches on combustion in microgravity were conducted to develop combustion devices for advanced combustion techniques, and thereby to cope with the requirements for diversification of energy sources and abatement of environmental pollution by exhaust gases. This project was implemented under the research cooperation agreement with US's NASA, and the Japanese experts visited NASA's test facilities. NASA's Lewis Research Center has drop test facilities, of which the 2.2-sec drop test facilities are useful for researches by Japan. The cooperative research themes for combustion in microgravity selected include interactions between fuel droplets, high-pressure combustion of binary fuel sprays, and ignition and subsequent flame propagation in microgravity. An ignition test equipment, density field measurement equipment and flame propagation test equipment were constructed in Japan to conduct the combustion tests in microgravity for, e.g., combustion and evaporation of fuel droplets, combustion characteristics of liquid fuels mixed with solid particles, combustion of coal/oil mixture droplets, and estimating flammability limits. (NEDO)

  7. Sodium nitrate combustion limit tests

    International Nuclear Information System (INIS)

    Beitel, G.A.

    1976-04-01

    Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

  8. Variable compression ratio device for internal combustion engine

    Science.gov (United States)

    Maloney, Ronald P.; Faletti, James J.

    2004-03-23

    An internal combustion engine, particularly suitable for use in a work machine, is provided with a combustion cylinder, a cylinder head at an end of the combustion cylinder and a primary piston reciprocally disposed within the combustion cylinder. The cylinder head includes a secondary cylinder and a secondary piston reciprocally disposed within the secondary cylinder. An actuator is coupled with the secondary piston for controlling the position of the secondary piston dependent upon the position of the primary piston. A communication port establishes fluid flow communication between the combustion cylinder and the secondary cylinder.

  9. Systems and methods of storing combustion waste products

    Science.gov (United States)

    Chen, Shen-En; Wang, Peng; Miao, Xiexing; Feng, Qiyan; Zhu, Qianlin

    2016-04-12

    In one aspect, methods of storing one or more combustion waste products are described herein. Combustion waste products stored by a method described herein can include solid combustion waste products such as coal ash and/or gaseous combustion products such as carbon dioxide. In some embodiments, a method of storing carbon dioxide comprises providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure and flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete.

  10. Fuel properties to enable lifted-flame combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Eric [Ford Motor Company, Dearborn, MI (United States)

    2015-03-15

    The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental

  11. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

  12. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

  13. Combustion in a High-Speed Compression-Ignition Engine

    Science.gov (United States)

    Rothrock, A M

    1933-01-01

    An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur. The results show that by increasing the air temperature during injection the start of combustion can be forced to take place during injection and so prevent detonation from occurring. It is shown that the rate of fuel injection does not in itself control the rate of combustion.

  14. CFD analysis of premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber

    International Nuclear Information System (INIS)

    Gera, B.; Singh, R.K.; Vaze, K.K.

    2014-01-01

    Premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber has been performed numerically using commercial CFD code CFD-ACE+. The combustion chamber had dimensions 1 m X 0.024 m X 1 m. Simulations were carried out for 10% (v/v) hydrogen concentration for which experimental results were available. Effect of different boundary condition and ignition position on flame propagation was studied. Time dependent flame propagation in the chamber was predicted by CFD code. The computed transient flame propagation in the chamber was in good agreement with experimental results. The present work demonstrated that the available commercial CFD codes are capable of modeling hydrogen deflagration in a realistic manner. (author)

  15. Flex-flame burner and combustion method

    Science.gov (United States)

    Soupos, Vasilios; Zelepouga, Serguei; Rue, David M.; Abbasi, Hamid A.

    2010-08-24

    A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

  16. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  17. Combustion characteristics of crude jatropha oil droplets using rhodium liquid as a homogeneous combustion catalyst

    Science.gov (United States)

    Nanlohy, Hendry Y.; Wardana, I. N. G.; Hamidi, N.; Yuliati, L.

    2018-01-01

    Combustion characteristics of crude jatropha oil droplet at room temperature with and without catalyst have been studied experimentally. Its combustion characteristics have been observed by igniting the oil droplet on a junction of a thermocouple, and the combustion characteristics of oil droplets are observed using a high-speed camera. The results show that the uniqueness of crude jatropha oil as alternative fuel is evidenced by the different stages of combustion caused by thermal cracking in burning droplets. The results also show that the role of the catalyst is not only an accelerator agent, but there are other unique functions and roles as a stabilizer. Moreover, the results also found that the catalyst was able to shorten the ignition timing and burnout time. This phenomenon proves that the presence of catalysts alters and weakens the structure of the triglyceride geometry so that the viscosity and flash point is reduced, the fuel absorbs heat well and flammable.

  18. A study of the current group evaporation/combustion theories

    Science.gov (United States)

    Shen, Hayley H.

    1990-01-01

    Liquid fuel combustion can be greatly enhanced by disintegrating the liquid fuel into droplets, an effect achieved by various configurations. A number of experiments carried out in the seventies showed that combustion of droplet arrays and sprays do not form individual flames. Moreover, the rate of burning in spray combustion greatly deviates from that of the single combustion rate. Such observations naturally challenge its applicability to spray combustion. A number of mathematical models were developed to evaluate 'group combustion' and the related 'group evaporation' phenomena. This study investigates the similarity and difference of these models and their applicability to spray combustion. Future work that should be carried out in this area is indicated.

  19. Final report: Prototyping a combustion corridor; FINAL

    International Nuclear Information System (INIS)

    Rutland, Christopher J.; Leach, Joshua

    2001-01-01

    The Combustion Corridor is a concept in which researchers in combustion and thermal sciences have unimpeded access to large volumes of remote computational results. This will enable remote, collaborative analysis and visualization of state-of-the-art combustion science results. The Engine Research Center (ERC) at the University of Wisconsin - Madison partnered with Lawrence Berkeley National Laboratory, Argonne National Laboratory, Sandia National Laboratory, and several other universities to build and test the first stages of a combustion corridor. The ERC served two important functions in this partnership. First, we work extensively with combustion simulations so we were able to provide real world research data sets for testing the Corridor concepts. Second, the ERC was part of an extension of the high bandwidth based DOE National Laboratory connections to universities

  20. Combustion of stratified hydrogen-air mixtures in the 10.7 m3 Combustion Test Facility cylinder

    International Nuclear Information System (INIS)

    Whitehouse, D.R.; Greig, D.R.; Koroll, G.W.

    1996-01-01

    This paper presents preliminary results from hydrogen concentration gradient combustion experiments in a 10.7 m 3 cylinder. These gradients, also referred to as stratified mixtures, were formed from dry mixtures of hydrogen and air at atmospheric temperature. Combustion pressures, burn fractions and flame speeds in concentration gradients were compared with combustion of well-mixed gases containing equivalent amounts of hydrogen. The studied variables included the quantity of hydrogen in the vessel, the steepness of the concentration gradient, the igniter location, and the initial concentration of hydrogen at the bottom of the vessel. Gradients of hydrogen and air with average concentrations of hydrogen below the downward propagation limit produced significantly greater combustion pressures when ignited at the top of the vessel than well-mixed gases with the same quantity of hydrogen. This was the result of considerably higher burn fractions in the gradients than in the well-mixed gas tests. Above the downward propagation limit, gradients of hydrogen ignited at the top of the vessel produced nearly the same combustion pressures as under well-mixed conditions; both gradients and well-mixed gases had high burn fractions. Much higher flame speeds were observed in the gradients than the well-mixed gases. Gradients and well-mixed gases containing up to 14% hydrogen ignited at the bottom of the vessel produced nearly the same combustion pressures. Above 14% hydrogen, gradients produced lower combustion pressures than well-mixed gases having the same quantity of hydrogen. This can be attributed to lower burn fractions of fuel from the gradients compared with well-mixed gases with similar quantities of hydrogen. When ignited at the bottom of the vessel, 90% of a gradient's gases remained unburned until several seconds after ignition. The remaining gases were then consumed at a very fast rate. (orig.)

  1. Combustion Modeling with the G-Equation Modélisation de la combustion avec l'équation de G

    Directory of Open Access Journals (Sweden)

    Peters N.

    2006-12-01

    Full Text Available Numerical investigations concerning the turbulent flame front propagation in Gasoline Direct Injection (GDI engines were made by implementing a flamelet model in the CFD code Fire. The advantage of this combustion model is the decoupling of the chemistry from the turbulent flow. For this purpose the combustion chamber has to be divided into a burned and an unburned area, which is realized by transporting a scalar field (G-Equation. The reference value defines the present averaged flame position. The complete reaction kinetics is calculated interactively with the CFD code in a one dimensional Representative Interactive Flamelet (RIF code. This combustion model was verified by simulating a 2. 0 l-2 V gasoline engine with homogeneous combustion where a parameter study was conducted to check the flamelet model for plausibility. Finally, the potential of this combustion model was investigated by simulating a hypothetical 2. 0 1-4 V GDI engine. Une investigation numérique relative à la propagation des fronts de flammes turbulents dans les moteurs à essence à injection directe (GDI a été menée en implantant un modèle de flameletdans le code 3D Fire. L'avantage de ce modèle de combustion est de découpler la chimie de l'écoulement turbulent en divisant la chambre de combustion en deux zones : brûlée et imbrûlée, à l'aide d'une équation de transport d'un scalaire (équation de G. Une valeur de référence de ce scalaire définit la position moyenne de la flamme. Une chimie complète est calculée interactivement avec le calcul 3D à l'aide d'un code monodimensionnel RIF (Representative Interactive Flamelet. Le modèle de combustion a été validé sur la simulation d'un moteur 2 litres à 2 soupapes en combustion homogène pour vérifier la représentativité de l'approche flamelet . Puis, le potentiel du modèle de combustion a été étudié en simulant un moteur modèle 2 litres 4 soupapes GDI.

  2. Reaction and diffusion in turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pope, S.B. [Mechanical and Aerospace Engineering, Ithaca, NY (United States)

    1993-12-01

    The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

  3. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    spectral measurements at several line-of-sights with a view to applications for tomographic measurements on full-scale industrial combustion systems. The system was successfully applied on industrial scale for simultaneous fast exhaust gas temperature measurements in the three optical ports of the exhaust......D project, it was also important to investigate the spectral properties of major combustion species such as carbon dioxide and carbon monoxide in the infrared range at high temperatures to provide the theoretical background for the development of the optical tomography methods. The new software....... JQSRT 113 (2012) 2222, 10.1016/j.jqsrt.2012.07.015] included in the PhD thesis as an attachment. The knowledge and experience gained in the PhD project is the first important step towards introducing the advanced optical tomography methods of combustion diagnostics developed in the project to future...

  4. High Pressure Combustion Experimental Facility(HPCEF) for Studies on Combustion in Reactive Flows

    Science.gov (United States)

    2017-12-13

    SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6...Report: High Pressure Combustion Experimental Facility (HPCEF) for Studies on Combustion in Reactive Flows The views, opinions and/or findings... contained in this report are those of the author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so

  5. Oxy combustion with CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

    An update for oxyfuel-combustion carbon capture in the power industry is provided. The report was developed by the Electric Power Research Institute (EPRI) on behalf of the Global CCS Institute. In the oxyfuel-combustion processes, the bulk nitrogen is removed from the air before combustion. The resulting combustion products will have CO2 content up to about 90 per cent (dry basis). The flue gas impurities (predominantly O2, N2, and Ar) may be removed by reducing the flue gas (at moderate pressure) to a temperature at which the CO2 condenses and the impurities do not. Oxyfuel-combustion may be employed with solid fuels such as coal, petroleum coke, and biomass, as well as liquid and gaseous fuels. Some key points raised in the oxyfuel-combustion carbon capture report are: The oxyfuel-combustion/CO2 capture power plant designs being developed and deployed for service in the next four or five years are based on individual component technologies and arrangements which have demonstrated sufficient maturity, with the greatest remaining technical challenge being integrating the systems into a complete steam-electric power plant; By its nature, an oxyfuel-coal power plant is likely to be a 'near zero' emitter of all criteria pollutants; Existing air-fired power plants might be retrofitted with an air separation unit, oxyfuel-fired burners, flue gas recycle, and a CO2 processing unit, with the large fleet of air-fired power plants in service calling for more study of this option; and, Future efficiency improvements to the oxyfuel-combustion process for power generation point toward an oxyfuel-combustion plant with near zero emissions of conventional pollutants, up to 98 per cent CO2 capture, and efficiency comparable to the best power plants currently being built.

  6. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H [VTT Energy, Jyvaeskylae (Finland)

    1997-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  7. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  8. Reactivity studies of rice husk combustion using TGA

    International Nuclear Information System (INIS)

    Ismail, A.F.; Shamsuddin, A.H.; Mahdi, F.M.A.

    2000-01-01

    The reactivity of rice husks combustion is systematically studied the thermogravimetric analyzer (TGA). The kinetic parameters are determined from the Arrhenius plots based on the data of weight loss over temperature at different combustion heating rates. The results of proximate analysis (the moisture, volatile matters, fixed carbon, and ash contents) are also presented in this paper. The effects of process conditions on the self-ignition phenomenon of rice husk combustion are quantified. Finally, these results and compared with results for coal combustion. This research is part of the work to determine the optimal process conditions of rice husk combustion for energy production. (Author)

  9. Large-eddy simulation of swirling pulverized-coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.Y.; Luo, Y.H. [Shanghai Jiaotong Univ. (China). School of Mechanical Engineering; Zhou, L.X.; Xu, C.S. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics

    2013-07-01

    A Eulerian-Lagrangian large-eddy simulation (LES) with a Smagorinsky-Lilly sub-grid scale stress model, presumed-PDF fast chemistry and EBU gas combustion models, particle devolatilization and particle combustion models are used to study the turbulence and flame structures of swirling pulverized-coal combustion. The LES statistical results are validated by the measurement results. The instantaneous LES results show that the coherent structures for pulverized coal combustion is stronger than that for swirling gas combustion. The particles are concentrated in the periphery of the coherent structures. The flame is located at the high vorticity and high particle concentration zone.

  10. Boiler for combustion fuel in a fluidized bed

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2015-01-01

    Full Text Available Fuel combustion in fluidized bed combustion is a process that is current and which every day gives more attention and there are many studies that have been closely associated with this technology. This combustion technology is widespread and constantly improving the range of benefits it provides primarily due to reduced emissions. This paper presents the boilers for combustion in a fluidized bed, whit characteristics and advantages. Also is shown the development of this type of boilers in Republic of Serbia. In this paper is explained the concept of fluidized bed combustion. Boilers for this type of combustion can be improved and thereby increase their efficiency level. More detailed characteristics are given for boilers with bubbling and circulating fluidized bed as well as their mutual comparison.

  11. Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-09-01

    In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

  12. Combustion tests with different pellet qualities

    International Nuclear Information System (INIS)

    Bachs, A.; Dahlstroem, J.E.; Persson, Henrik; Tullin, C.

    1999-05-01

    Eight different pellet qualities with the diameters 6, 8 and 10 mm, from eight different producers has been tested in three pellet burners and two pellet stoves. The objective was to investigate how different diameter affect the emissions of CO, OGC and NO x . Previous experience has indicated that the pellet diameter could have significant importance for the combustion. This was not verified in the study. It showed contradictory that the diameter has a minor effect on the combustion result. The study shows that different combustion equipment give different emission. For e g hydrocarbon emissions the difference is a factor 2.2 between the 'best' and the 'worst' equipment fired on full load. The difference increases to 2.7 with lower load. The choice of fuel has a big importance for the quality of the combustion. For hydrocarbons the emissions could in an extreme situation differ with a factor 25 between 'best' and 'worst' fuel. More normally the difference is about a factor of five. Nitrogen oxide emissions are to a major part related to the nitrogen contents in the fuel. The difference between the 'best' and 'worst' fuel is in the range of a factor two. Tests with the same fuel in different equipment gives a variation of 20-30%. The combustion result depends on both the pellet quality and the equipment and there is no fuel that is good in all equipment. The big variation in combustion results shows that there is a big indifference between fuels used for small scale heating Project report from the program: Small scale combustion of biofuels. 2 refs, 15 figs, 5 tabs

  13. Hydrogen combustion modelling in large-scale geometries

    International Nuclear Information System (INIS)

    Studer, E.; Beccantini, A.; Kudriakov, S.; Velikorodny, A.

    2014-01-01

    Hydrogen risk mitigation issues based on catalytic recombiners cannot exclude flammable clouds to be formed during the course of a severe accident in a Nuclear Power Plant. Consequences of combustion processes have to be assessed based on existing knowledge and state of the art in CFD combustion modelling. The Fukushima accidents have also revealed the need for taking into account the hydrogen explosion phenomena in risk management. Thus combustion modelling in a large-scale geometry is one of the remaining severe accident safety issues. At present day there doesn't exist a combustion model which can accurately describe a combustion process inside a geometrical configuration typical of the Nuclear Power Plant (NPP) environment. Therefore the major attention in model development has to be paid on the adoption of existing approaches or creation of the new ones capable of reliably predicting the possibility of the flame acceleration in the geometries of that type. A set of experiments performed previously in RUT facility and Heiss Dampf Reactor (HDR) facility is used as a validation database for development of three-dimensional gas dynamic model for the simulation of hydrogen-air-steam combustion in large-scale geometries. The combustion regimes include slow deflagration, fast deflagration, and detonation. Modelling is based on Reactive Discrete Equation Method (RDEM) where flame is represented as an interface separating reactants and combustion products. The transport of the progress variable is governed by different flame surface wrinkling factors. The results of numerical simulation are presented together with the comparisons, critical discussions and conclusions. (authors)

  14. Verification of Conditions for use of Combustion Products‘ Heat

    Directory of Open Access Journals (Sweden)

    Kažimírová Viera

    2015-06-01

    Full Text Available Presented contribution deals with the verification of conditions for use of combustion products‘ heat, generated by combustion of wood in a fireplace used in a household. It is necessary to know the temperature behaviour of the fireplace to determine the adequacy of the technical solution for using combustion products‘ heat. The combustion products‘ temperature at the upper part of the chimney is 80-120 °C. The dew point value was established to be below 51 °C. The average observed value of combustion product velocity is 1.6 m s-1. The volume flow rate of combustion products is 12 m3 h-1. Measured values allow for effective solution of the use of combustion products‘ heat.

  15. Separating Direct and Indirect Turbofan Engine Combustion Noise While Estimating Post-Combustion (Post-Flame) Residence Time Using the Correlation Function

    Science.gov (United States)

    Miles, Jeffrey Hilton

    2011-01-01

    A previous investigation on the presence of direct and indirect combustion noise for a full-scale turbofan engine using a far-field microphone at 130 is extended by also examining signals obtained at two additional downstream directions using far-field microphones at 110 deg and 160 deg. A generalized cross-correlation function technique is used to study the change in propagation time to the far field of the combined direct and indirect combustion noise signal as a sequence of low-pass filters are applied. The filtering procedure used produces no phase distortion. As the low-pass filter frequency is decreased, the travel time increases because the relative amount of direct combustion noise is reduced. The indirect combustion noise signal travels more slowly because in the combustor entropy fluctuations move with the flow velocity, which is slow compared to the local speed of sound. The indirect combustion noise signal travels at acoustic velocities after reaching the turbine and being converted into an acoustic signal. The direct combustion noise is always propagating at acoustic velocities. The results show that the estimated indirect combustion noise time delay values (post-combustion residence times) measured at each angle are fairly consistent with one another for a relevant range of operating conditions and demonstrate source separation of a mixture of direct and indirect combustion noise. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting turbofan engine core noise.

  16. Experimental validation for combustion analysis of GOTHIC 6.1b code in 2-dimensional premixed combustion experiments

    International Nuclear Information System (INIS)

    Lee, J. Y.; Lee, J. J.; Park, K. C.

    2003-01-01

    In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. In the experimental results, we could confirm the propagation characteristics of hydrogen flame such as buoyancy effect, flame front shape etc.. The combustion time of the tests was about 0.1 sec.. In the GOTHIC analyses results, the GOTHIC code could predict the overall hydrogen flame propagation characteristics but the buoyancy effect and flame shape did not compare well with the experimental results. Especially, in case of the flame propagate to the dead-end, GOTHIC predicted the flame did not affected by the flow and this cause quite different results in flame propagation from experimental results. Moreover the combustion time of the analyses was about 1 sec. which is ten times longer than the experimental result. To obtain more reasonable analysis results, it is necessary that combustion model parameters in GOTHIC code apply appropriately and hydrogen flame characteristics be reflected in solving governing equations

  17. System and method for engine combustion

    Science.gov (United States)

    Sczomak, David P.; Gallon, Robert J.; Solomon, Arun S.

    2018-03-13

    A combustion system for use with one or more cylinder bores of an internal combustion engine includes at least one cylinder head defining first and second intake ports in fluid communication with the one or more cylinder bores. A flap is adjustably connected to the at least one cylinder head. The flap includes a first flap portion cooperating with the first intake port extending from an arm and a second flap portion cooperating with the second intake port extending from the arm and disposed adjacent the first flap portion. A controller in electrical communication with an actuator monitors the condition of the engine and actuates the flap to position the first and second flap portions between first and second positions to create a first combustion condition and a second combustion condition.

  18. Techniques for Liquid Rocket Combustion Spontaneous Stability and Rough Combustion Assessments

    Science.gov (United States)

    Kenny, R. J.; Giacomoni, C.; Casiano, M. J.; Fischbach, S. R.

    2016-01-01

    This work presents techniques for liquid rocket engine combustion stability assessments with respect to spontaneous stability and rough combustion. Techniques covering empirical parameter extraction, which were established in prior works, are applied for three additional programs: the F-1 Gas Generator (F1GG) component test program, the RS-84 preburner component test program, and the Marshall Integrated Test Rig (MITR) program. Stability assessment parameters from these programs are compared against prior established spontaneous stability metrics and updates are identified. Also, a procedure for comparing measured with predicted mode shapes is presented, based on an extension of the Modal Assurance Criterion (MAC).

  19. Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

    Science.gov (United States)

    Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

    2015-02-03

    The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions.

  20. Apuntes sobre esporotricosis

    OpenAIRE

    Londoño, Fabio

    2011-01-01

    Se hace una breve reseña histórica de las primeras comunicaciones sobre esporotricosis. Se destaca la amplia difusión de la enfermedad en nuestro país. 3. Se hace notar la no existencia de datos bibliográficos sobre formas extracutáneas. 4. Se llama la atención sobre la eficaz ayuda de la intradermo-reacción con esporotriquina en el diagnóstico de la enfermedad. 5- Se comunica un caso de esporotricosis verrugosa tratado con anfotericin B, con excelentes resultados

  1. Apuntes sobre esporotricosis

    Directory of Open Access Journals (Sweden)

    Fabio Londoño

    1960-01-01

    Full Text Available Se hace una breve reseña histórica de las primeras comunicaciones sobre esporotricosis. Se destaca la amplia difusión de la enfermedad en nuestro país. 3. Se hace notar la no existencia de datos bibliográficos sobre formas extracutáneas. 4. Se llama la atención sobre la eficaz ayuda de la intradermo-reacción con esporotriquina en el diagnóstico de la enfermedad. 5- Se comunica un caso de esporotricosis verrugosa tratado con anfotericin B, con excelentes resultados

  2. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-12-01

    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  3. Mechanisms and kinetics of granulated sewage sludge combustion.

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2015-12-01

    This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects of streamwise vortex breakdown on supersonic combustion.

    Science.gov (United States)

    Hiejima, Toshihiko

    2016-04-01

    This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1.

  5. Language and World: Wittgenstein and Manoel de Barros

    OpenAIRE

    Oliva, Osmar Pereira

    2011-01-01

    Este ensaio pretende discutir concepções de linguagem e de mundo, a partir da filosofia wittgensteiniana presente no Tractatus Logico-philosophicus, e da poética de Manoel de Barros, em Livro sobre nada. Discutirá, também, os conceitos de forma lógica, verdade e figuração, com exemplos de estruturas lingüísticas poéticas, aproximando proposição filosófica e criação literária. ...

  6. Evaluación como un proceso de construcción colectiva

    OpenAIRE

    González, Marina Cecilia

    2016-01-01

    La evaluación es por naturaleza compleja y multidimensional. Se caracteriza, por interpretaciones de diferentes intensidades y matices sobre las múltiples dimensiones del aprender de cada alumno, que se realizan a partir de concepciones de educación, de sujeto y de sociedad. De esta forma, los “juicios” de cada evaluador son siempre complejos y subjetivos en la medida de que provienen de esa trama de conceptos multidimensionales (Anijovich, 2010). Las verdades son siempre provisorias en la ev...

  7. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  8. Development of a NO/x/-free combustion system

    Science.gov (United States)

    Sadakata, M.; Furusawa, T.; Kunii, D.; Imagawa, M.; Nawada, M.

    1980-04-01

    The development of a NO(x)-free combustion-heating system realizing both pollution control and energy savings is described. An experiment was carried out by using a small model plant. The system consists of a combustion furnace and a new-type multifunctional heat exchanger. The heat exchanger is a rotary continuous type designed for soot collection and for catalytic combustion of CO and H2 as well as for preheating combustion air.

  9. Combustion and Ignition Studies of Nanocomposite Energetic Materials

    Science.gov (United States)

    2010-12-14

    Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

  10. The John Zink Hamworthy combustion handbook

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Despite the length of time it has been around, its importance, and vast amounts of research, combustion is still far from being completely understood. Issues regarding the environment, cost, and fuel consumption add further complexity, particularly in the process and power generation industries. Dedicated to advancing the art and science of industrial combustion, The John Zink Hamworthy Combustion Handbook, Second Edition: Volume 3 - Applications offers comprehensive, up-to-date coverage of equipment used in the process and power generation industries. Under the leadership of Charles E. Baukal

  11. Chaotic combustion in spark ignition engines

    International Nuclear Information System (INIS)

    Wendeker, Miroslaw; Czarnigowski, Jacek; Litak, Grzegorz; Szabelski, Kazimierz

    2003-01-01

    We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process

  12. Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

    Directory of Open Access Journals (Sweden)

    Horváth Jozef

    2015-06-01

    Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

  13. Emission characteristics of premixed lean diesel combustion. Effects of injection nozzle and combustion chamber shape on combustion and emission characteristics; Kihaku yokongo diesel nensho no haishutsubutsu tokusei. Funmu keijo oyobi nenshoshitsu keijo ga haishutsu gas tokusei ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Harada, A; Sasaki, S; Miyamoto, T; Akagawa, H; Tsujimura, K

    1997-10-01

    Many articles about low NOx emission combustion are reported. A mixture formation is necessary to success low NOx emission combustion. But, there is few reports about the effect of nozzle and combustion shape on emissions which give influence on mixture. In this paper, the effects on characteristic of combustion and emissions of some land of injection nozzle and combustion chamber shape were investigated. As a result, it was cleared that the influence of combustion chamber shape on characteristic of combustion and emissions was varied by spray shape, and pintle type injection nozzle was suitable for PREDIC. 7 refs., 10 figs., 1 tab.

  14. Dispersions of Oxides in Oxide Matrices as High-Temperature Reactor Fuels; Dispersions d'oxyde dans des matrices d'oxyde, utilisees comme combustibles dans des reacteurs a haute temperature; Dispersiya okisej v okislovykh matritsakh v kachestve topliva dlya vysokotemperaturnogo reaktora; Empleo de dispersiones de oxidos en matrices de oxidos, como combustibles para reactores de elevada temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J. [Atomic Energy Research Establishment, Harwell (United Kingdom)

    1963-11-15

    posibilidad de utilizar dispersiones de PuO{sub 2}, UO2 y ThO{sub 2} en matrices de BeO, Al{sub 2}O{sub 3}, MgO y SIO{sub 2}, desde el punto de vista de la integridad y elaboracion del combustible. Las dos caracteristicas mas importantes en lo que atane a la integridad del combustible son su estabilidad dimensional y su capacidad de retener los productos de fision. La compatibilidad de los componentes del combustible entre si, y entre ellos y el refrigerante, influye en la estabilidad dimensional, pero en este aspecto, las propiedades de los combustibles en forma de oxido son satisfactorias. A la alteracion de las dimensiones del combustible por irradiacion contribuyen los factores siguientes: deterioracion de la matriz por los neutrones y los fragmentos de fision, deteriorizacion de la fase fisionable/fertil por las radiaciones y gases de los productos de fision acumulados. Las tensiones termicas pueden tambien provocar deformaciones. Los conocimientos que se poseen sobre los mecanismos de atenuacion de tensiones son, sin embargo, insuficientes para permitir un estudio teorico razonable del comportamiento de los materiales. Los estudios sobre la liberacion de productos de fision por los oxidos fisionables/fertiles, realizados tanto en condiciones de irradiacion poco intensa como de elevado grado de combustion, han tratado principalmente de los productos gaseosos, en particular del xenon. Los datos que se poseen sobre el desprendimiento de otros productos de fision son muy escasos, lo mismo que los conocimientos sobre el movimiento de los productos de fision en general a traves de los materiales que podrian utilizarse como matrices. De los estudios realizados sobre la permeabilidad de los oxidos puros sinterizados, se deduce que se deberan alcanzar densidades teoricas de 95%, como minimo, o quiza incluso de 98%, paca eliminar la porosidad de dichas matrices. Se han elaborado una serie de procedimientos para preparar las particulas fisionables/fertiles, para revestirlas y para

  15. A comprehensive study of combustion products generated from pulverized peat combustion in the furnace of BKZ-210-140F steam boiler

    Science.gov (United States)

    Kuzmin, V. A.; Zagrai, I. A.

    2017-11-01

    The experimental and theoretical study of combustion products has been carried out for the conditions of pulverized peat combustion in BKZ-210-140F steam boiler. Sampling has been performed in different parts of the boiler system in order to determine the chemical composition, radiative properties and dispersity of slag and ash particles. The chemical composition of particles was determined using the method of x-ray fluorescence analysis. Shapes and sizes of the particles were determined by means of electron scanning microscopy. The histograms and the particle size distribution functions were computed. The calculation of components of the gaseous phase was based on the combustion characteristics of the original fuel. The software package of calculation of thermal radiation of combustion products from peat combustion was used to simulate emission characteristics (flux densities and emissivity factors). The dependence of emission characteristics on the temperature level and on the wavelength has been defined. On the basis of the analysis of emission characteristics the authors give some recommendations how to determine the temperature of peat combustion products in the furnace of BKZ-210-140F steam boiler. The findings can be used to measure the combustion products temperature, support temperature control in peat combustion and solve the problem of boiler furnace slagging.

  16. Numerical Studies on Controlling Gaseous Fuel Combustion by Managing the Combustion Process of Diesel Pilot Dose in a Dual-Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2015-06-01

    Full Text Available Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.

  17. AKR1C1 as a Biomarker for Differentiating the Biological Effects of Combustible from Non-Combustible Tobacco Products.

    Science.gov (United States)

    Woo, Sangsoon; Gao, Hong; Henderson, David; Zacharias, Wolfgang; Liu, Gang; Tran, Quynh T; Prasad, G L

    2017-05-03

    Smoking has been established as a major risk factor for developing oral squamous cell carcinoma (OSCC), but less attention has been paid to the effects of smokeless tobacco products. Our objective is to identify potential biomarkers to distinguish the biological effects of combustible tobacco products from those of non-combustible ones using oral cell lines. Normal human gingival epithelial cells (HGEC), non-metastatic (101A) and metastatic (101B) OSCC cell lines were exposed to different tobacco product preparations (TPPs) including cigarette smoke total particulate matter (TPM), whole-smoke conditioned media (WS-CM), smokeless tobacco extract in complete artificial saliva (STE), or nicotine (NIC) alone. We performed microarray-based gene expression profiling and found 3456 probe sets from 101A, 1432 probe sets from 101B, and 2717 probe sets from HGEC to be differentially expressed. Gene Set Enrichment Analysis (GSEA) revealed xenobiotic metabolism and steroid biosynthesis were the top two pathways that were upregulated by combustible but not by non-combustible TPPs. Notably, aldo-keto reductase genes, AKR1C1 and AKR1C2 , were the core genes in the top enriched pathways and were statistically upregulated more than eight-fold by combustible TPPs. Quantitative real time polymerase chain reaction (qRT-PCR) results statistically support AKR1C1 as a potential biomarker for differentiating the biological effects of combustible from non-combustible tobacco products.

  18. Internal Heterogeneous Processes in Aluminum Combustion

    Science.gov (United States)

    Dreizin, E. L.

    1999-01-01

    This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (combustion behavior and the evolution of its internal composition, the change from the spherically symmetric to asymmetric flame shape occurring upon the transition from stage I to stage II combustion could not be understood based only on the fact that dissolved oxygen is detected in the particles. The connection between the two phenomena appeared even less significant because in earlier aluminum combustion studies carried in O2/Ar mixtures, flame asymmetry was not observed as opposed to experiments in air or O2/CO mixtures. It has been proposed that the presence of other gases, i.e., hydrogen, or nitrogen causes the change in the combustion regime.

  19. Science review of internal combustion engines

    International Nuclear Information System (INIS)

    Taylor, Alex M.K.P.

    2008-01-01

    Internal combustion engines used in transportation produce about 23% of the UK's carbon dioxide emission, up from 14% in 1980. The current science described in this paper suggests that there could be 6-15% improvements in internal combustion fuel efficiency in the coming decade, although filters to meet emission legislation reduce these gains. Using these engines as hybrids with electric motors produces a reduction in energy requirements in the order of 21-28%. Developments beyond the next decade are likely to be dominated by four topics: emission legislation and emission control, new fuels, improved combustion and a range of advanced concepts for energy saving. Emission control is important because current methods for limiting nitrogen oxides and particulate emissions imply extra energy consumption. Of the new fuels, non-conventional fossil-derived fuels are associated with larger greenhouse gas emissions than conventional petroleum-based fuels, while a vehicle propelled by fuel cells consuming non-renewable hydrogen does not necessarily offer an improvement in emissions over the best hybrid internal combustion engines. Improved combustion may be developed for both gasoline and diesel fuels and promises better efficiency as well as lower noxious emissions without the need for filtering. Finally, four advanced concepts are considered: new thermodynamic cycles, a Rankine bottoming cycle, electric turbo-compounding and the use of thermoelectric devices. The latter three all have the common theme of trying to extract energy from waste heat, which represents about 30% of the energy input to an internal combustion engine

  20. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  1. Research on combustion of black-liquor drops

    International Nuclear Information System (INIS)

    Macek, A.

    1999-01-01

    Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practised for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) re-examines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. (author)

  2. Low emission turbulent technology for fuel combustion

    International Nuclear Information System (INIS)

    Finker, F. Z.; Kubyshkin, I. B.; Zakharov, B. Yu.; Akhmedov, D. B.; Sobchuk, Ch.

    1997-01-01

    The company 'POLITEKHENERGO' in co-operation and the Russian-Poland firm 'EnergoVIR' have performed investigations for modernization of the current existing boilers. A low emission turbulent technology has been used for the modernization of 10 industrial boilers. The reduction of NO x emissions is based on the following processes: 1) multistage combustion assured by two counter-deviated fluxes; 2) Some of the combustion facilities have an abrupt slope and a reduced air supply which leads to an intense separation of the fuel in the bottom part and a creation of a low-temperature combustion zone where the active restoration of the NO x takes part; 3) The influence of the top high-temperature zone on the NO x formation is small. Thus the 'sandwich' consisting of 'cold' and'hot' combustion layers provides a full rate combustion. This technique permits to: decrease of the NO x and CO x down to the European standard values;increase of the efficiency in 1-2%; obtain a stable coal combustion up to 97-98%; assure the large loading range (30 -100%); modernize and use the old boilers

  3. Simulation of lean premixed turbulent combustion

    International Nuclear Information System (INIS)

    Bell, J; Day, M; Almgren, A; Lijewski, M; Rendleman, C; Cheng, R; Shepherd, I

    2006-01-01

    There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels such as hydrogen or syngas. Lean premixed systems have the potential to burn these types of fuels with high efficiency and low NOx emissions due to reduced burnt gas temperatures. Although traditional Scientific approaches based on theory and laboratory experiment have played essential roles in developing our current understanding of premixed combustion, they are unable to meet the challenges of designing fuel-flexible lean premixed combustion devices. Computation, with its ability to deal with complexity and its unlimited access to data, has the potential for addressing these challenges. Realizing this potential requires the ability to perform high fidelity simulations of turbulent lean premixed flames under realistic conditions. In this paper, we examine the specialized mathematical structure of these combustion problems and discuss simulation approaches that exploit this structure. Using these ideas we can dramatically reduce computational cost, making it possible to perform high-fidelity simulations of realistic flames. We illustrate this methodology by considering ultra-lean hydrogen flames and discuss how this type of simulation is changing the way researchers study combustion

  4. Solid waste combustion for alpha waste incineration

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1981-02-01

    Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

  5. Study of experimental validation for combustion analysis of GOTHIC code

    International Nuclear Information System (INIS)

    Lee, J. Y.; Yang, S. Y.; Park, K. C.; Jeong, S. H.

    2001-01-01

    In this study, present lumped and subdivided GOTHIC6 code analyses of the premixed hydrogen combustion experiment at the Seoul National University and comparison with the experiment results. The experimental facility has 16367 cc free volume and rectangular shape. And the test was performed with unit equivalence ratio of the hydrogen and air, and with various location of igniter position. Using the lumped and mechanistic combustion model in GOTHIC6 code, the experiments were simulated with the same conditions. In the comparison between experiment and calculated results, the GOTHIC6 prediction of the combustion response does not compare well with the experiment results. In the point of combustion time, the lumped combustion model of GOTHIC6 code does not simulate the physical phenomena of combustion appropriately. In the case of mechanistic combustion model, the combustion time is predicted well, but the induction time of calculation data is longer than the experiment data remarkably. Also, the laminar combustion model of GOTHIC6 has deficiency to simulate combustion phenomena unless control the user defined value appropriately. And the pressure is not a proper variable that characterize the three dimensional effect of combustion

  6. A comprehensive review of oil spill combustion studies

    International Nuclear Information System (INIS)

    Walavalkar, A.Y.; Kulkarni, A.K.

    1996-01-01

    The complex process of in-situ burning of oil or a water-in-oil emulsion floating on top of a water-base, such as the ocean, was discussed. The process was examined before, during and after actual combustion. In general, the success of oil spill combustion is measured in terms of the fraction of the spilled oil or emulsion that is burned away. However, the air and aquatic pollution caused by the combustion should also be considered. The physical conditions such as wind velocity, waves and the presence or absence of a containment device, such as a fire boom, could determine the continuation of the combustion process. An overview of the oil spill combustion techniques was provided. There still remains a need for fundamental studies, especially in mathematical modeling, to understand the basic mechanisms and predict the applicability of the in-situ combustion. 74 refs., 7 tabs., 3 figs

  7. Formation of fuel NOx during black-liquor combustion

    International Nuclear Information System (INIS)

    Nichols, K.M.; Lien, S.J.

    1993-01-01

    Fuel NOx and thermal NOx were measured in combustion gases from black liquors in two laboratory furnaces. Combustion at 950 C in air (8% O 2 ) produced NOx concentrations of 40-80ppm. Combustion at 950 C in synthetic air containing no nitrogen (21% 0 2 in Ar) produced the same result, demonstrating that all of the NOx produced during combustion at 950 C was fuel NOx. Formation of fuel NOx increased moderately with increasing temperature in the range of 800-1,000 C, but temperature sensitivity of fuel NOx was much less than that of thermal NOx. The results imply that the major source of NOx in recovery furnace emissions is the fuel NOx in recovery furnace formed by conversion of liquor-bound nitrogen during combustion. This is consistent with thermal NOx theory, which postulates that black-liquor combustion temperatures are too low to generate significant amounts of thermal NOx

  8. Improvement of a combustion model in MELCOR code

    International Nuclear Information System (INIS)

    Ogino, Masao; Hashimoto, Takashi

    1999-01-01

    NUPEC has been improving a hydrogen combustion model in MELCOR code for severe accident analysis. In the proposed combustion model, the flame velocity in a node was predicted using five different flame front shapes of fireball, prism, bubble, spherical jet, and plane jet. For validation of the proposed model, the results of the Battelle multi-compartment hydrogen combustion test were used. The selected test cases for the study were Hx-6, 13, 14, 20 and Ix-2 which had two, three or four compartments under homogeneous hydrogen concentration of 5 to 10 vol%. The proposed model could predict well the combustion behavior in multi-compartment containment geometry on the whole. MELCOR code, incorporating the present combustion model, can simulate combustion behavior during severe accident with acceptable computing time and some degree of accuracy. The applicability study of the improved MELCOR code to the actual reactor plants will be further continued. (author)

  9. Key factors of combustion from kinetics to gas dynamics

    CERN Document Server

    Rubtsov, Nikolai M

    2017-01-01

    This book summarizes the main advances in the mechanisms of combustion processes. It focuses on the analysis of kinetic mechanisms of gas combustion processes and experimental investigation into the interrelation of kinetics and gas dynamics in gas combustion. The book is complimentary to the one previously published, The Modes of Gaseous Combustion.

  10. Sulfur equilibrium desulfurization of sulfur containing products of combustion

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Abichandani, J.S.

    1990-01-01

    This patent describes the method for the combustion of a carbon- and sulfur-containing fuel for substantially reducing emission of gaseous sulfur compounds formed during combustion of the fuel in a combustion zone. The zone having one or more fuel inlets and one or more oxidizer inlets, and having a combustion products outlet spaced therefrom, and having one or more inorganic sorbent inlets downstream of the fuel inlet(s) and oxidizer inlet(s) and upstream of the combustion products outlet

  11. Fuel effect on solution combustion synthesis of Co(Cr,Al)2O4 pigments; Efecto del combustible en la síntesis de pigmentos Co(Cr,Al)2O4 por combustión de una disolución

    Energy Technology Data Exchange (ETDEWEB)

    Gilabert, J.; Palacios, M.D.; Sanz, V.; Mestre, S.

    2017-11-01

    por los pigmentos, una vez introducidos en un esmalte cerámico transparente, muestra variaciones importantes por el efecto de la composición. Por el contrario, prácticamente no se aprecia el efecto del combustible, ya que se obtienen tonos de color similares entre las muestras. Sin embargo, sí es posible destacar cierto efecto sobre el componente responsable de la luminosidad.

  12. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2014-06-01

    Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

  13. Enhancement of exergy efficiency in combustion systems using flameless mode

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Exergy efficiency in flameless combustion mode is 13% more than conventional combustion. • The maximum exergy efficiency in flameless combustion mode is achieved when oxidizer contains 10% oxygen. • Exergy destruction of flameless combustion is maximized when CO 2 is used for dilution of oxidizer. - Abstract: An exergitic-based analysis of methane (CH 4 ) conventional and flameless combustion in a lab-scale furnace is performed to determine the rate of pollutant formation and the effective potential of a given amount of fuel in the various combustion modes. The effects of inlet air temperature on exergy efficiency and pollutant formation of conventional combustion in various equivalence ratios are analyzed. The rate of exergy destruction in different conditions of flameless combustion (various equivalence ratios, oxygen concentration in the oxidizer and the effects of diluent) are computed using three-dimensional (3D) computational fluid dynamic (CFD). Fuel consumption reduction and exergy efficiency augmentation are the main positive consequences of using preheated air temperature in conventional combustion, however pollutants especially NO x formation increases dramatically. Low and moderate temperature inside the chamber conducts the flameless combustion system to low level pollutant formation. Fuel consumption and exergy destruction reduce drastically in flameless mode in comparison with conventional combustion. Exergy efficiency of conventional and flameless mode is 75% and 88% respectively in stoichiometric combustion. When CO 2 is used for dilution of oxidizer, chemical exergy increases due to high CO 2 concentration in the combustion products and exergy efficiency reduces around 2% compared to dilution with nitrogen (N 2 ). Since the rate of irreversibilities in combustion systems is very high in combined heat and power (CHP) generation and other industries, application of flameless combustion could be effective in terms of pollutant

  14. Numerical investigation of spray combustion towards HITAC conditions

    NARCIS (Netherlands)

    Zhu, Shanglong

    2017-01-01

    The features of High Temperature Air Combustion (HiTAC), i.e. high-efficiency combustion processes creating a uniform temperature distribution with low NOX and CO emissions, lend itself ideally for the combustion of all sorts of "difficult” fuels, ranging from low-calorific gases such as

  15. Method for storing radioactive combustible waste

    Science.gov (United States)

    Godbee, H.W.; Lovelace, R.C.

    1973-10-01

    A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

  16. Combustion and extinction of magnesium fires

    International Nuclear Information System (INIS)

    Malet, J.C.; Duverger de Cuy, G.

    1988-01-01

    The studies made in France on magnesium combustion and extinguishing means are associated at the nuclear fuel of the graphite-gas reactor. Safety studies are made for ameliorate our knowledge on: - magnesium combustion - magnesium fire propagation - magnesium fire extinguishing [fr

  17. Combustion-derived substances in deep basins of Puget Sound: Historical inputs from fossil fuel and biomass combustion

    International Nuclear Information System (INIS)

    Kuo, Li-Jung; Louchouarn, Patrick; Herbert, Bruce E.; Brandenberger, Jill M.; Wade, Terry L.; Crecelius, Eric

    2011-01-01

    Reconstructions of 250 years historical inputs of two distinct types of black carbon (soot/graphitic black carbon (GBC) and char-BC) were conducted on sediment cores from two basins of the Puget Sound, WA. Signatures of polycyclic aromatic hydrocarbons (PAHs) were also used to support the historical reconstructions of BC to this system. Down-core maxima in GBC and combustion-derived PAHs occurred in the 1940s in the cores from the Puget Sound Main Basin, whereas in Hood Canal such peak was observed in the 1970s, showing basin-specific differences in inputs of combustion byproducts. This system showed relatively higher inputs from softwood combustion than the northeastern U.S. The historical variations in char-BC concentrations were consistent with shifts in climate indices, suggesting an influence of climate oscillations on wildfire events. Environmental loading of combustion byproducts thus appears as a complex function of urbanization, fuel usage, combustion technology, environmental policies, and climate conditions. - Research highlights: → We reconstructed the historical inputs of GBC and char-BC in Puget Sound, WA, USA. → Temporal trend of GBC was linked to human activities (urbanization, fuel usage). → Temporal trend of char-BC was more likely driven by regional climate oscillations. → Historical trends of combustion byproducts show the geographical heterogeneities. - Temporal trend of GBC was directly linked to human activities, while the input of char-BC in Puget Sound was more likely driven by regional climate oscillations.

  18. Extended lattice Boltzmann scheme for droplet combustion.

    Science.gov (United States)

    Ashna, Mostafa; Rahimian, Mohammad Hassan; Fakhari, Abbas

    2017-05-01

    The available lattice Boltzmann (LB) models for combustion or phase change are focused on either single-phase flow combustion or two-phase flow with evaporation assuming a constant density for both liquid and gas phases. To pave the way towards simulation of spray combustion, we propose a two-phase LB method for modeling combustion of liquid fuel droplets. We develop an LB scheme to model phase change and combustion by taking into account the density variation in the gas phase and accounting for the chemical reaction based on the Cahn-Hilliard free-energy approach. Evaporation of liquid fuel is modeled by adding a source term, which is due to the divergence of the velocity field being nontrivial, in the continuity equation. The low-Mach-number approximation in the governing Navier-Stokes and energy equations is used to incorporate source terms due to heat release from chemical reactions, density variation, and nonluminous radiative heat loss. Additionally, the conservation equation for chemical species is formulated by including a source term due to chemical reaction. To validate the model, we consider the combustion of n-heptane and n-butanol droplets in stagnant air using overall single-step reactions. The diameter history and flame standoff ratio obtained from the proposed LB method are found to be in good agreement with available numerical and experimental data. The present LB scheme is believed to be a promising approach for modeling spray combustion.

  19. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner

    Directory of Open Access Journals (Sweden)

    Yik Siang Pang

    2018-01-01

    Full Text Available This paper presents a Computational Fluid Dynamics (CFD study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO and spherical harmonics (P1 model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM. Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen. The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE and renormalized k-ε (RNG. The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 155-169 (doi:10.9767/bcrec

  20. A method for determining the completeness of fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tavger, M.D.; Chepkin, V.M.; Gruzdev, V.N.; Talantov, A.V.

    1982-01-01

    The current of conductivity (ionization) of gaseous combustion products, which forms with feeding of electric voltage to a special probe, is proposed for determining the completeness of fuel combustion. Here, the charged particles are formed from substances which form in the intermediate stages of the combustion reaction. The volume of charged particles is proportional to the volume of the intermediate substances, whose presence attests to the incompleteness of the combustion reaction. The fullness of fuel combustion is determined from a formula which includes the stoichiometric coefficient, a gas constant, the energy of activation, the characteristics of the chemical activity of the intermediate substances, the coefficient of air excess, the temperature of the combustion products and the conductivity current.

  1. Combustion chemistry - activities in the CHEK research programme

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, K.; Johnsson, J.E.; Glarborg, P.; Frandsen, F.; Jensen, A.; Oestberg, M. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

    1997-10-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This presentation describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control) Research Programme. (orig.)

  2. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

    2003-05-01

    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  3. 30 CFR 56.4103 - Fueling internal combustion engines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

  4. 30 CFR 57.4103 - Fueling internal combustion engines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

  5. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

  6. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    Science.gov (United States)

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  7. Predicción del efecto de la temperatura sobre la viscosidad del biodiesel de aceite de palma y sus mezclas con diesel convencional.

    OpenAIRE

    Benjumea, Pedro N; Álvarez, Ángela M; Molina, Alexandra P

    2011-01-01

    La viscosidad es una propiedad fundamental para los combustibles que se utilizan en motores de encendido por compresión o motores diesel. En este artículo se presentan correlaciones empíricas, tipo ecuación de Andrade, para predecir el efecto de la temperatura sobre la viscosidad cinemática y absoluta del biodiesel de aceite de palma. Se utilizaron tres tipos de biodiesel obtenidos a partir del aceite crudo de palma y sus fases oleína y estearina. Adicionalmente, se analiza el comportamiento ...

  8. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sören

    2017-11-22

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

  9. Micro-combustion calorimetry employing a Calvet heat flux calorimeter

    International Nuclear Information System (INIS)

    Rojas-Aguilar, Aaron; Valdes-Ordonez, Alejandro

    2004-01-01

    Two micro-combustion bombs developed from a high pressure stainless steel vessel have been adapted to a Setaram C80 Calvet calorimeter. The constant of each micro-bomb was determined by combustions with benzoic acid NIST 39j, giving for the micro-combustion bomb in the measurement sensor k m =(1.01112±0.00054) and for the micro-combustion bomb in the reference sensor k r =(1.00646±0.00059) which means an uncertainty of less than 0.06 per cent for calibration. The experimental methodology to get results of combustion energy of organic compounds with a precision also better than 0.06 per cent is described by applying this micro-combustion device to the measurement of the enthalpy of combustion of the succinic acid, giving Δ c H compfn m (cr, T=298.15 K)=-(1492.89 ± 0.77) kJ · mol -1

  10. Flameless Combustion Workshop

    National Research Council Canada - National Science Library

    Gutmark, Ephraim

    2005-01-01

    .... "Flameless Combustion" is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean stability limits and therefore extremely low NOx production, efficient...

  11. Combustion/particle sizing experiments at the Naval Postgraduate School Combustion Research Laboratory

    Science.gov (United States)

    Powers, John; Netzer, David

    1987-01-01

    Particle behavior in combustion processes is an active research area at NPS. Currently, four research efforts are being conducted: (1) There is a long standing need to better understand the soot production and combustion processes in gas turbine combustors, both from a concern for improved engine life and to minimize exhaust particulates. Soot emissions are strongly effected by fuel composition and additives; (2) A more recent need for particle sizing/behavior measurements is in the combustor of a solid fuel ramjet which uses a metallized fuel. High speed motion pictures are being used to study rather large burning particles; (3) In solid propellant rocket motors, metals are used to improve specific impulse and/or to provide damping for combustion pressure oscillations. Particle sizing experiments are being conducted using diode arrays to measure the light intensity as a function of scattering angle; (4) Once a good quality hologram is attained, a need exists for obtaining the particle distributions from hologram in a short period of time. A Quantimet 720 Image Analyzer is being used to reconstruct images.

  12. Two phase exhaust for internal combustion engine

    Science.gov (United States)

    Vuk, Carl T [Denver, IA

    2011-11-29

    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  13. 30 CFR 56.7807 - Flushing the combustion chamber.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber...

  14. Combustion chemistry. Activities in the CHEC research programme

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, K; Johnsson, J E; Glarborg, P; Frandsen, F; Jensen, A; Oestberg, M [Technical Univ. of Denmark, Dept. of Chemical Engineering, Lyngby (Denmark)

    1996-12-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This paper describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control Research Programme). (au) 173 refs.

  15. Quasi-dimensional modeling of a fast-burn combustion dual-plug spark-ignition engine with complex combustion chamber geometries

    International Nuclear Information System (INIS)

    Altın, İsmail; Bilgin, Atilla

    2015-01-01

    This study builds on a previous parametric investigation using a thermodynamic-based quasi-dimensional (QD) cycle simulation of a spark-ignition (SI) engine with dual-spark plugs. The previous work examined the effects of plug-number and location on some performance parameters considering an engine with a simple cylindrical disc-shaped combustion chamber. In order to provide QD thermodynamic models applicable to complex combustion chamber geometries, a novel approach is considered here: flame-maps, which utilizes a computer aided design (CAD) software (SolidWorks). Flame maps are produced by the CAD software, which comprise all the possible flame radiuses with an increment of one-mm between them, according to the spark plug positions, spark timing, and piston position near the top dead center. The data are tabulated and stored as matrices. Then, these tabulated data are adapted to the previously reported cycle simulation. After testing for simple disc-shaped chamber geometries, the simulation is applied to a real production automobile (Honda-Fit) engine to perform the parametric study. - Highlights: • QD model was applied in dual plug engine with complex realistic combustion chamber. • This method successfully modeled the combustion in the dual-plug Honda-Fit engine. • The same combustion chamber is tested for various spark plug(s) locations. • The centrally located single spark-plug results in the fastest combustion

  16. Combustion Research Facility | A Department of Energy Office of Science

    Science.gov (United States)

    Collaborative Research Facility Back to Sandia National Laboratory Homepage Combustion Research Search the CRF Combustion Chemistry Flame Chemistry Research.Combustion_Chemistry.Flame_Chemistry Theory and Modeling Theory and Modeling Combustion Kinetics High Pressure Chemistry Chemistry of Autoignition

  17. La fotografía como estandarte de la verdad y el progreso: Estudio sobre la iconografía fotográfica en la medallística (1880-1920

    Directory of Open Access Journals (Sweden)

    Jorge L. Crespo Armáiz

    2013-04-01

    Full Text Available Desde el momento de su creación a mediados del siglo XIX, la invención fotográfica representó un cambio profundo en la mentalidad de la sociedad decimonónica en lo relativo a su impacto en la reproducción y diseminación de las imágenes visuales. Durante las primeras décadas siguientes a su invención, los entusiastas de la fotografía propulsaron un discurso de superioridad mimética de la misma por sobre las artes visuales tradicionales, sobre la base de la supuesta objetividad absoluta de su registro óptico-químico. La fuerza de esta mentalidad discursiva del nuevo paradigma visual se reflejó en la literatura y demás expresiones culturales, incluyendo las propias artes plásticas. A través de un análisis iconográfico de un conjunto de medallas del período se pueden identificar los signos, códigos y discursos relativos a la fotografía como reflejo de las mentalidades positivistas imperantes de la época.Since its invention in the first half of the nineteenth century, photography represented a profound change in the mentality of European society regarding its impact in the reproduction and dissemination of visual images. During its initial developmental stage, fanatics of the new medium gave impulse to a discourse of mimetic superiority of photography over traditional visual arts, based upon the alleged absolute objectivity of its optical-chemical registry. This discursive mentality reflected its influence in literature, as well as in other cultural expressions, including the visual arts. Through the implementation of an iconographic analysis of a sample of award and commemorative medals of this period, this article looks to identify those signs, codes and discourses related to photography as symbol of progress and absolute truth within the positivism paradigm.

  18. Internal combustion engines in hybrid vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de; Beckman, D.E.

    1998-01-01

    In this paper the use of internal combustion engines in hybrid powertrains is investigated. The substantial difference between the use of internal combustion engines in conventional and in hybrid vehicles mean that engines for hybrid vehicles should be designed specifically for the purpose. At the

  19. Evaluation of gas radiation models in CFD modeling of oxy-combustion

    International Nuclear Information System (INIS)

    Rajhi, M.A.; Ben-Mansour, R.; Habib, M.A.; Nemitallah, M.A.; Andersson, K.

    2014-01-01

    Highlights: • CFD modeling of a typical industrial water tube boiler is conducted. • Different combustion processes were considered including air and oxy-fuel combustion. • SGG, EWBM, Leckner, Perry and WSGG radiation models were considered in the study. • EWBM is the most accurate model and it’s considered to be the benchmark model. • Characteristics of oxy-fuel combustion are compared to those of air–fuel combustion. - Abstract: Proper determination of the radiation energy is very important for proper predictions of the combustion characteristics inside combustion devices using CFD modeling. For this purpose, different gas radiation models were developed and applied in the present work. These radiation models vary in their accuracy and complexity according to the application. In this work, a CFD model for a typical industrial water tube boiler was developed, considering three different combustion environments. The combustion environments are air–fuel combustion (21% O 2 and 79% N 2 ), oxy-fuel combustion (21% O 2 and 79% CO 2 ) and oxy-fuel combustion (27% O 2 and 73% CO 2 ). Simple grey gas (SGG), exponential wide band model (EWBM), Leckner, Perry and weighted sum of grey gases (WSGG) radiation models were examined and their influences on the combustion characteristics were evaluated. Among those radiation models, the EWBM was found to provide close results to the experimental data for the present boiler combustion application. The oxy-fuel combustion characteristics were analyzed and compared with those of air–fuel combustion

  20. Characteristic of combustion of Colombian gases

    International Nuclear Information System (INIS)

    Gil B, Edison; Maya, Ruben; Andres, Amel A.

    1996-01-01

    The variety of gas locations in the country, makes that the gas that will be distributed by the net of present gas pipeline a very different composition, what bears to that these they behave in a different way during its use. In this work the main characteristics of the combustion are calculated for the Colombian gases, basically the properties of the combustion and the characteristics of the smoke, as basic information for the design and operation of the gas teams and their certification. These properties were calculated with the special help software for combustion developed by the authors

  1. Plasma assisted combustion of parafin mixture

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya.; Martysh, E.V.; Lisitchenko, T.E.; Vergun, O.Yu.; Orlovska, S.G.

    2013-01-01

    In this work the results of solid paraffin combustion with the aid of the plasma of transverse and rotational gliding arc studies are represented. The question of the additional activation of paraffin based solid fuels is examined. The mixture of n-paraffin and stearin in the solid state as the model of the solid paraffin based fuel is used. The plasma assisted combustion of this model is experimentally investigated. The voltage-current characteristics of discharge at the different regimes are measured. The population temperatures of excited rotational levels are determined. The flame temperature during the combustion of solid paraffin containing mixture is calculated

  2. Combustion of lean hydrogen-air mixtures in the connected compartments

    International Nuclear Information System (INIS)

    Fan Liu; Yoshio Yoshizawa; Akio Miyori; Kenya Kubota

    1997-01-01

    A study of combustion experiments with premixed lean hydrogen-air mixtures was conducted in a vessel consisting of two compartments connected by a diameter-variable vent. Effects of various parameters (hydrogen concentration, vent diameter and initial pressure) on mechanical loads of the combustion processes including mainly the peak pressures and the rates of pressure rise were investigated. Relation of flow and combustion was approached. Ignition-combustion processes were discussed, and the combustion types were classified into three patterns according to the pressure-time histories and the flow characteristics in main combustion compartment

  3. 2017 Laser Diagnostics in Combustion GRC/GRS

    Science.gov (United States)

    2017-10-06

    scientists and engineers . The goal of GRC was to bring together scientists and engineers with a strong interest in laser-based combustion diagnostics to...processes. The GRS, held the weekend before the GRC, was organized to bring together emerging leaders in the field at an early stage in their careers ...coupled multi-scale combustion processes. The GRC on Laser Diagnostics in Combustion was designed to bring together scientists and engineers working at

  4. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.

    2013-01-01

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation....... In this work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property model, gas-phase combustion mechanism and heterogeneous char reaction model. The sub-models were...... implemented in CFD (Computational Fluid Dynamics) simulations of combustion of three coals under air-firing and various oxy-firing (21-35% vol O2 in O2/CO2 mixture) conditions in an EFR (entrained flow reactor). The predicted coal burnouts and gaseous emissions were compared against experimental results...

  5. Co-combustion of waste materials using fluidized bed technology

    Energy Technology Data Exchange (ETDEWEB)

    M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2004-07-01

    There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

  6. Disturbing effect of free hydrogen on fuel combustion in internal combustion engines

    Science.gov (United States)

    Riedler, A

    1923-01-01

    Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots.

  7. HPA e Nitro-HPA em Ambiente Semifechado Impactado por Emissão da Combustão de Diesel/Biodiesel (B5

    Directory of Open Access Journals (Sweden)

    Fabio Cal Sabino

    2015-09-01

    Full Text Available Com o objetivo de verificar a presença de HPA e nitro-HPA associados à fração fina do material particulado (MP1,0 e MP2,5 proveniente da combustão de mistura diesel/biodiesel (B5 foram realizadas amostragens diárias no terminal urbano de ônibus de Londrina. Para a determinação do nitro-HPA foi utilizada a espectroscopia de massa acoplado à cromatografia a líquido com ionização química a pressão atmosférica e detector por aprisionamento de íons. Os HPA foram determinados por cromatografia a líquido com detecções por fluorescência e arranjo de fotodiodos. Foram determinados 9 HPA e 1-nitropireno. As concentrações dos HPA de 4 a 6 anéis (FLUT, PIR, CRI, BBF, BKF e DBA foram mais elevadas em comparação aos HPA mais leves (ACE, FLU e ANT. A ∑HPA associado ao MP1,0 correspondeu a 66% do MP2,5 com concentrações que excedem ao recomendado pela OMS. As razões de diagnóstico para pares de HPA e NHPA foram calculadas e seus valores são indicativos das emissões B5. O uso de bicombustíveis no território brasileiro é estimulado e o acompanhamento das alterações nas emissões decorrentes dos processos de combustão é importante e necessário para inferir sobre a alteração da qualidade do ar e o impacto sobre o ambiente.

  8. Scramjet Combustion Stability Behavior Modeling, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the potential to predict the combustion stability of a scramjet. This capability is very...

  9. 30 CFR 57.7807 - Flushing the combustion chamber.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 57.7807... and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be...

  10. COMBUSTION OF BIOMASS AND CHARCOAL MADE FROM BABASSU NUTSHELL

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2017-03-01

    Full Text Available In recent years, studies have examined the use of lignocellulosic wastes for energy generation. However, there is a lack of information on the combustibility of the residual biomass, especially the bark and charcoal of babassu nut. In this study, thermogravimetric analysis (TGA, differential thermal analysis (DTA and differential scanning calorimetry (DSC were used to achieve the following objectives: to evaluate the combustion of the residual biomass from the babassu nut; to evaluate the combustion of charcoal produced from this biomass, considering different final carbonization temperatures; and to determine the effect of the final carbonization temperature on the thermal stability of charcoal and on its performance in combustion. Thermal analyses were performed in synthetic air. In order to evaluate the characteristics of charcoal combustion and fresh biomass, the ignition temperature (Ti, the burnout temperature (Tf, characteristic combustion index (S, ignition index (Di, time corresponding to the maximum combustion rate (tp, and ignition time (tig were considered. The combustion of the babassu nutshell occurred in three phases and it was observed that this lignocellulosic material is suitable for the direct generation of heat. The increase in the final carbonization temperature caused an increase in the ignition temperature, as well as in the burnout temperature, the ignition time and the time corresponding to the maximum combustion rate. The results indicate that the increase in the carbonization temperature causes a decrease in combustion reactivity and, consequently, the charcoals produced at lower temperatures are easier to ignite and exhibit better performance in ignition.

  11. Staged combustion with piston engine and turbine engine supercharger

    Science.gov (United States)

    Fischer, Larry E [Los Gatos, CA; Anderson, Brian L [Lodi, CA; O'Brien, Kevin C [San Ramon, CA

    2011-11-01

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  12. Modelo estadístico que permite observar el impacto de los factores que inciden en el rendimiento de combustible

    Directory of Open Access Journals (Sweden)

    Rosa Amelia Alcántar Ruiz

    2015-01-01

    Full Text Available El presente trabajo propone un modelo estadístico de regresión lineal múltiple para la toma de decisiones sobre el rendimiento de combustible con aplicación a la industria del autotransporte en México considerando los factores con mayor incidencia en el consumo. El modelo aplicado tiene significancia estadística, así como las variables explicativas: tipo de ruta, antigüedad y cantidad de diésel consumido en baja, esto con un nivel de confianza del 95%, lográndose explicar un 94% del efecto de interés modelado. La contribución fundamental de este artículo es proponer un modelo estadístico como una nueva herramienta de gestión para los tomadores de decisiones del sector, en relación al establecimiento de estándares de combustible y la administración en general de este insumo, puesto que fue determinado a partir de las condiciones operativas de la industria del transporte y no bajo condiciones experimentales (difíciles de replicar empleadas por el fabricante del automotor.

  13. Mixing and combustion enhancement of Turbocharged Solid Propellant Ramjet

    Science.gov (United States)

    Liu, Shichang; Li, Jiang; Zhu, Gen; Wang, Wei; Liu, Yang

    2018-02-01

    Turbocharged Solid Propellant Ramjet is a new concept engine that combines the advantages of both solid rocket ramjet and Air Turbo Rocket, with a wide operation envelope and high performance. There are three streams of the air, turbine-driving gas and augment gas to mix and combust in the afterburner, and the coaxial intake mode of the afterburner is disadvantageous to the mixing and combustion. Therefore, it is necessary to carry out mixing and combustion enhancement research. In this study, the numerical model of Turbocharged Solid Propellant Ramjet three-dimensional combustion flow field is established, and the numerical simulation of the mixing and combustion enhancement scheme is conducted from the aspects of head region intake mode to injection method in afterburner. The results show that by driving the compressed air to deflect inward and the turbine-driving gas to maintain strong rotation, radial and tangential momentum exchange of the two streams can be enhanced, thereby improving the efficiency of mixing and combustion in the afterburner. The method of injecting augment gas in the transverse direction and making sure the injection location is as close as possible to the head region is beneficial to improve the combustion efficiency. The outer combustion flow field of the afterburner is an oxidizer-rich environment, while the inner is a fuel-rich environment. To improve the efficiency of mixing and combustion, it is necessary to control the injection velocity of the augment gas to keep it in the oxygen-rich zone of the outer region. The numerical simulation for different flight conditions shows that the optimal mixing and combustion enhancement scheme can obtain high combustion efficiency and have excellent applicability in a wide working range.

  14. ¿Fútbol de verdad? : Observaciones narratológicas sobre los relatos en vivo

    OpenAIRE

    Martínez, Matías

    2011-01-01

    En el relato periodístico retrospectivo de un partido de futbol –el de Chile contra México por la Copa América, el 30 de junio de 1999- se puede observar el uso de diversos elementos narratológicos que lo vuelven interesante. Los reportajes de distintos diarios chilenos contienen crónicas, historias y esquemas narrativos construidos a partir del antagonismo entre adversarios, el protagonismo de ciertos personajes y los puntos culminantes que ellos viven. Además, hay en los relatos una identif...

  15. A REVIEW OF MILD COMBUSTION AND OPEN FURNACE DESIGN CONSIDERATION

    Directory of Open Access Journals (Sweden)

    M.M. Noor

    2012-12-01

    Full Text Available Combustion is still very important to generate energy. Moderate or Intense Low-oxygen Dilution (MILD combustion is one of the best new technologies for clean and efficient combustion. MILD combustion has been proven to be a promising combustion technology in industrial applications with decreased energy consumption due to the uniformity of its temperature distribution. It is clean compared to traditional combustion due to producing low NOx and CO emissions. This article provides a review and discussion of recent research and developments in MILD. The issue and applications are summarized, with some suggestions presented on the upgrading and application of MILD in the future. Currently MILD combustion has been successfully applied in closed furnaces. The preheating of supply air is no longer required since the recirculation inside the enclosed furnace already self-preheats the supply air and self-dilutes the oxygen in the combustion chamber. The possibility of using open furnace MILD combustion will be reviewed. The design consideration for open furnace with exhaust gas re-circulation (EGR was discussed.

  16. High Gravity (g) Combustion

    Science.gov (United States)

    2006-02-01

    UNICORN (Unsteady Ignition and Combustion with Reactions) code10. Flame propagation in a tube that is 50-mm wide and 1000-mm long (similar to that...turbine engine manufacturers, estimating the primary zone space heating rate. Both combustion systems, from Company A and Company B, required a much...MBTU/atm-hr-ft3) Te m pe ra tu re R is e (K ) dP/P = 2% dP/P = 2.5% dP/P = 3% dP/P = 3.5% dP/P = 4% Company A Company B Figure 13: Heat Release Rate

  17. Publication sites productive uses of combustion ash

    Science.gov (United States)

    Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

  18. Scramjet Combustion Stability Behavior Modeling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the means to accurately predict the combustion stability of a scramjet. This capability is very...

  19. Production of nanocrystalline metal powders via combustion reaction synthesis

    Science.gov (United States)

    Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.; Kim, Jin Yong

    2017-10-31

    Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

  20. Torrefaction of empty fruit bunches under biomass combustion gas atmosphere.

    Science.gov (United States)

    Uemura, Yoshimitsu; Sellappah, Varsheta; Trinh, Thanh Hoai; Hassan, Suhaimi; Tanoue, Ken-Ichiro

    2017-11-01

    Torrefaction of oil palm empty fruit bunches (EFB) under combustion gas atmosphere was conducted in a batch reactor at 473, 523 and 573K in order to investigate the effect of real combustion gas on torrefaction behavior. The solid mass yield of torrefaction in combustion gas was smaller than that of torrefaction in nitrogen. This may be attributed to the decomposition enhancement effect by oxygen and carbon dioxide in combustion gas. Under combustion gas atmosphere, the solid yield for torrefaction of EFB became smaller as the temperature increased. The representative products of combustion gas torrefaction were carbon dioxide and carbon monoxide (gas phase) and water, phenol and acetic acid (liquid phase). By comparing torrefaction in combustion gas with torrefaction in nitrogen gas, it was found that combustion gas can be utilized as torrefaction gas to save energy and inert gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. New combustion, environment regulations: the answers for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France)

    1997-12-31

    This paper reports on the point of view from Gaz de France (GdF) company concerning the potential consequences of the use of natural gas in combustion systems with respect to the new regulations about combustion and environment. Details concerning the measures relative to the limitation of pollutants in small combustion installations (2 - 20 MW) are given (chimney height, SO{sub x}, NO{sub x} and dusts content in exhaust gases). (J.S.)

  2. ¿Garantismo extremo o mesurado? La legitimidad de la función jurisdiccional penal: construyendo el debate Ferrajoli-Laudan

    OpenAIRE

    Edgar R. Aguilera García

    2014-01-01

    El objetivo del trabajo consiste en revisar dos versiones del argumento que concibe a la averiguación de la verdad como un factor que confiere legitimidad al ejercicio de la función jurisdiccional penal: la de Ferrajoli y la de Laudan. Se sostiene que su estudio minucioso puede proporcionar bases racionales (no meramente emotivas) para decidir sobre la conveniencia de suscribir un garantismo extremo (Ferrajoli) o uno de carácter más mesurado (Laudan). Esta decisión cobra relevancia en el cont...

  3. Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei

    2015-01-01

    This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2 concentrations were used, spanning 10-21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH∗ with the increase of ambient temperature and O2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O2 concentration conditions by the

  4. A literatura médica brasileira sobre a peste branca: 1870-1940 Brazilian medical literature about the white plague: 1870-1940

    Directory of Open Access Journals (Sweden)

    Dalila de Sousa Sheppard

    2001-06-01

    Full Text Available As teorias de Darwin constituem o paradigma escolhido pelos médicos do Sul dos Estados Unidos, quando se debruçaram sobre o tema de diferenças na morbidade e na mortalidade entre as raças após a abolição. Estes médicos teceram considerações sobre a crise de saúde que afetou a população descendente dos africanos naquela região. O mesmo não se deu com os médicos brasileiros ao tentarem entender e explicar a crise de saúde que afetou a população de descendência africana no seu país. Na verdade, em nenhum dos jornais médicos brasileiros, desde o final da abolição até a década de 1930, pode se encontrar um só artigo onde um médico atribuísse a morbilidade ou mortalidade de seus pacientes negros ou dos negros em geral, a qualquer fonte que usasse um paradigma racial como referência. Os psiquiatras e os médicos eugenistas foram exceção.The Darwinian theories compound the paradigm adopted by the physicians in Southern United States, when they turned to the subject of the differences in morbidity and mortality among the races after abolition. These physicians engaged in thoughts about the health crisis that assaulted the African-American population on that region. The Brazilian physicians, on the other hand, would not try to understand or explain the health crisis that overtook the population descended from Africans on their country. Actually, not a single Brazilian medical journal, since the end of abolition to the 1930s, published an article where a physician indicated the morbidity and mortality of his negro patients, or of negroes in general, as caused by any source related to a racial paradigm. The psychiatrists and eugenicist doctors were exceptions.

  5. Internal and Surface Phenomena in Heterogenous Metal Combustion

    Science.gov (United States)

    Dreizin, Edward L.

    1997-01-01

    The phenomenon of gas dissolution in burning metals was observed in recent metal combustion studies, but it could not be adequately explained by the traditional metal combustion models. The research reported here addresses heterogeneous metal combustion with emphasis on the processes of oxygen penetration inside burning metal and its influence on the metal combustion rate, temperature history, and disruptive burning. The unique feature of this work is the combination of the microgravity environment with a novel micro-arc generator of monodispersed metal droplets, ensuring repeatable formation and ignition of uniform metal droplets with a controllable initial temperature and velocity. Burning droplet temperature is measured in real time with a three wavelength pyrometer. In addition, particles are rapidly quenched at different combustion times, cross-sectioned, and examined using SEM-based techniques to retrieve the internal composition history of burning metal particles. When the initial velocity of a spherical particle is nearly zero, the microgravity environment makes it possible to study the flame structure, the development of flame nonsymmetry, and correlation of the flame shape with the heterogeneous combustion processes.

  6. A numerical study on the effect of various combustion bowl parameters on the performance, combustion, and emission behavior on a single cylinder diesel engine.

    Science.gov (United States)

    Balasubramanian, Dhinesh; Sokkalingam Arumugam, Sabari Rajan; Subramani, Lingesan; Joshua Stephen Chellakumar, Isaac JoshuaRamesh Lalvani; Mani, Annamalai

    2018-01-01

    A numerical study was carried out to study the effect of various combustion bowl parameters on the performance behavior, combustion characteristics, and emission magnitude on a single cylinder diesel engine. A base combustion bowl and 11 different combustion bowls were created by varying the aspect ratio, reentrancy ratio, and bore to bowl ratio. The study was carried out at engine rated speed and a full throttle performance condition, without altering the compression ratio. The results revealed that the combustion bowl parameters could have a huge impact on the performance behavior, combustion characteristics, and emission magnitude of the engine. The bowl parameters, namely throat diameter and toroidal radius, played a crucial role in determining the performance behavior of the combustion bowls. It was observed that the combustion bowl parameters, namely central pip distance, throat diameter, and bowl depth, also could have an impact on the combustion characteristics. And throat diameter and toroidal radius, central pip distance, and toroidal corner radius could have a consequent effect on the emission magnitude of the engine. Of the different combustion bowls tested, combustion bowl 4 was preferable to others owing to the superior performance of 3% of higher indicated mean effective pressure and lower fuel consumption. Interestingly, trade-off for NO x emission was higher only by 2.85% compared with the base bowl. The sensitivity analysis proved that bowl depth, bowl diameter, toroidal radius, and throat diameter played a vital role in the fuel consumption parameter and emission characteristics even at the manufacturing tolerance variations.

  7. 30 CFR 57.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

  8. LIEKKI 2 - Combustion technology is environmental technology

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M. [Aabo Akademi, Turku (Finland)

    1996-12-31

    Finland has wide experience in applications of various combustion technologies and fuels and in supplying energy to industry and municipalities. Furthermore, combustion hardware and equipment are amongst our most important export products. Above all, fluidized bed boilers, recovery boilers for pulp mills and heavy diesel engines and diesel power plants have achieved excellent success in the world markets. Exports of these products alone have amounted to several billions of Finnish marks of annual sales in recent years. Within modern combustion technology, the objective is to control flue gas emissions as far as possible in the process itself, thus doing away with the need for the separate scrubbing of flue gases. To accomplish this it has been necessary to conduct a large amount of research on the details of the chemistry of combustion emissions and the flows in furnaces and engine cylinders. A host of completely new products are being developed for the combustion technology field. The LIEKKI programme has been particularly interested in so-called combined-cycle processes based on pressurized fluidized bed technology

  9. Oxy-fuel combustion with integrated pollution control

    Science.gov (United States)

    Patrick, Brian R [Chicago, IL; Ochs, Thomas Lilburn [Albany, OR; Summers, Cathy Ann [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul Chandler [Independence, OR

    2012-01-03

    An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.

  10. Modeling of microgravity combustion experiments

    Science.gov (United States)

    Buckmaster, John

    1995-01-01

    This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

  11. Quantifying emissions from spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

  12. Spray combustion of biomass-based renewable diesel fuel using multiple injection strategy in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei; Wu, Zengyang; Roberts, William L.; Fang, Tiegang

    2016-01-01

    Effect of a two-injection strategy associated with a pilot injection on the spray combustion process was investigated under conventional diesel combustion conditions (1000 K and 21% O2 concentration) for a biomass-based renewable diesel fuel, i

  13. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  14. Dynamic estimator for determining operating conditions in an internal combustion engine

    Science.gov (United States)

    Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

    2016-01-05

    Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

  15. The release of nitrogen in coal combustion and pyrolysis

    International Nuclear Information System (INIS)

    Varey, J.E.; Hindmarsh, C.J.; Thomas, K.M.

    1994-01-01

    Environmental aspects of coal utilization are a major concern. Recent advances in the development of low NO x burners and the emerging technologies of fluidized bed combustion have led to the identification of coal char nitrogen as the major contributor to the nitrogen oxides released during combustion. The temperature programmed combustion and pyrolysis of a series of coals covering a wide range of rank have been investigated. In addition, maceral concentrates have been investigated to assess the variation in the combustion behavior and the release of nitrogen in the pyrolysis and combustion of macerals. This investigation has involved the use of thermogravimetric analysis - mass spectrometry (TG-MS) with two sampling options: (1) ∼1cm from the sample and (2) at the exit of the TG. The former allows reactive species to be identified in the combustion of the coals. These temperature programmed combustion results have been compared with similar measurements carried out at the exit of the TG where the products are at equilibrium. In addition, pyrolysis studies have been carried out under similar conditions. The results show that reactive intermediate species such as HCN, (CN) 2 , COS etc. can be detected in the combustion products. The evolution of these species during combustion are compared with the pyrolysis products of the coal. The results are discussed in relation to the structure of the coals and the conversion of volatile species and char nitrogen to nitrogen oxides

  16. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  17. 8th International symposium on transport phenomena in combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The 8th International Symposium on Transport Phenomena in Combustion will be held in San Francisco, California, U.S.A., July 16-20, 1995, under the auspices of the Pacific Center of Thermal-Fluids Engineering. The purpose of the Symposium is to provide a forum for researchers and practitioners from around the world to present new developments and discuss the state of the art and future directions and priorities in the areas of transport phenomena in combustion. The Symposium is the eighth in a series; previous venues were Honolulu 1985, Tokyo 1987, Taipei 1988, Sydney 1991, Beijing 1992, Seoul 1993 and Acapulco 1994, with emphasis on various aspects of transport phenomena. The current Symposium theme is combustion. The Symposium has assembled a balanced program with topics ranging from fundamental research to contemporary applications of combustion theory. Invited keynote lecturers will provide extensive reviews of topics of great interest in combustion. Colloquia will stress recent advances and innovations in fire spread and suppression, and in low NO{sub x} burners, furnaces, boilers, internal combustion engines, and other practical combustion systems. Finally, numerous papers will contribute to the fundamental understanding of complex processes in combustion. This document contains abstracts of papers to be presented at the Symposium.

  18. Research and development of hydrogen and fuel cells technology at the IIE; Investigacion y desarrollo de tecnologia de hidrogeno y celdas de combustible en el IIE

    Energy Technology Data Exchange (ETDEWEB)

    Cano C, Ulises; Arriaga H, Gerardo; Romero C, T; Medrano V, M. Consolacion; Gonzalez, A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    D relacionados con celdas de combustible iniciaron a partir de estudios basicos electroquimicos de electrodos de platino sobre carbon vitreo en soluciones acidas, para determinar parametros cineticos y propiedades estructurales. Puesto que los principales componentes de las celdas PEM definen en gran medida el costo de la tecnologia, otros esfuerzos adicionales ligados a estudios basicos para el desarrollo de componentes como placas bipolares, estan descritos por el mismo autor en el 2001. Otros trabajos sobre investigacion basica estan ligados a la repuesta de monoceldas de combustible a diferentes condiciones de operacion, y que tambien se revisaran en este articulo.

  19. 1998 annual report of advanced combustion science utilizing microgravity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the purpose of stabilizing energy supply, diversifying energy supply sources and reducing the worsening of global environment caused by combustion exhaust gases, advanced combustion technology was studied and the FY 1998 results were summarized. Following the previous year, the following were conducted: international research jointly with NASA, experiments using microgravity test facilities of Japan Space Utilization Promotion Center (JSUP), evaluation studies made by universities/national research institutes/private companies, etc. In the FY 1998 joint study, a total of 52 drop experiments were carried out on 4 themes using test facilities of Japan Microgravity Center (JAMIC), and 100 experiments were conducted on one theme using test facilities of NASA. In the study using microgravity test facilities, the following were carried out: study of combustion and evaporation of fuel droplets, study of ignition/combustion of fuel droplets in the suspending state, study of combustion of spherical/cylinder state liquid fuels, study of high pressure combustion of binary fuel spray, study of interaction combustion of fuel droplets in the microgravity field, etc. (NEDO)

  20. Combustion in fluidized bed reactors; Verbrennung in Wirbelschichtreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Thome-Kozmiensky, Karl J. [vivis CONSULT GmbH, Nietwerder (Germany)

    2013-03-01

    Since the first application for the coal gasification, the fluidized bed technology has passed an impressive development. Nowadays, the fluidized bed technology is utilized at chemical processes, drying and cooling, gasification, combustion and purification of exhaust gas. In the firing technology, the fluidized technology initially has been proved in the combustion of very high ash coal and sewage sludge. Recently, the fluidized bed technology also is applied in the drying of sewage sludge, combustion of domestic waste - as in Japan and Sweden - as well as in the gasification and combustion of substitute fuels, biomass - wood pellets, wood chips, straw, cocoa shells and so forth - and residues from the paper manufacturing - such as in Germany and Austria. Under this aspect, the author of the contribution under consideration reports on the combustion of sewage sludge, substitute fuels and biomass.

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