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Sample records for combustible aplicadas al

  1. Fuel cells applied to transport; Celdas de combustible aplicadas al transporte

    Energy Technology Data Exchange (ETDEWEB)

    Vargas Gonzalez, Miguel [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    2001-07-01

    The future demand of energy as well as the preservation of the environment have generated, in several countries, the necessity of developing alternative means for the most efficient transformation of energy that causes minimum damages to the environment. The fuel cells technology is outlined as one of the alternating means to the traditional forms of transforming the energy for residential use as well as for the automotive vehicles. At present it is in a final stage of demonstration, reason why as of year 2003 the possibility will exist on automobiles and trucks circulating normally. [Spanish] La futura demanda de energeticos asi como la preservacion del medio ambiente ha generado, en varios paises, la necesidad de desarrollar medios alternos para la transformacion mas eficiente de la energia que cause minimos danos al ambiente. La tecnologia de celdas de combustible se perfila como uno de los medios alternos a la forma tradicional de transformar la energia tanto para uso residencial como para los vehiculos automotores. En la actualidad se encuentra en una etapa final de demostracion por lo que posiblemente a partir del ano 2003 se cuente con automoviles y camiones circulando normalmente.

  2. La neuroplasticidad aplicada al deporte

    OpenAIRE

    Fernández, Hernán

    2015-01-01

    Me decidí a realizar la siguiente ponencia, para analizar y reconocer la importancia que implica el trabajo cognitivo en el entrenamiento deportivo. El abordaje que efectuaré, está enfocado en el desarrollo del entrenamiento cognitivo, su fundamento y el desarrollo de la neuroplasticidad. Analizaré el concepto de neuroplasticidad y neurogénesis como base al sustento teórico de la neurociencia aplicada al deporte. También remarcaré diversas metodologías prácticas, con su fundamento teóri...

  3. La neuroplasticidad aplicada al deporte

    OpenAIRE

    Fernández, Hernán

    2015-01-01

    Me decidí a realizar la siguiente ponencia, para analizar y reconocer la importancia que implica el trabajo cognitivo en el entrenamiento deportivo. El abordaje que efectuaré, está enfocado en el desarrollo del entrenamiento cognitivo, su fundamento y el desarrollo de la neuroplasticidad. Analizaré el concepto de neuroplasticidad y neurogénesis como base al sustento teórico de la neurociencia aplicada al deporte. También remarcaré diversas metodologías prácticas, con su fundamento teóri...

  4. Tecnologías actuales aplicadas al desarrollo urbano sustentable Tecnologías actuales aplicadas al desarrollo urbano sustentable

    Directory of Open Access Journals (Sweden)

    Aldemar Garduño Hernández

    2012-02-01

    Full Text Available This paper presents a review of information about new environmental technologies applied to urban development activities is organized and systematized. These technologies are justa portion of all technologies that can be applied to the development of cities, therefore, this paper is a presentation of the state of the art of new technologies being applied to sustainable urban development, which are mainly processes, precision tools, simulators, equipment, materials, and software and hardware, which facilitate the work of urban designers, architects and construction companies. El presente trabajo es un artículo de revisión en donde se organiza información de manera sistematizada sobre tecnologías ambientales aplicadas a cada una de las tareas y actividades que se realizan en la planeación y desarrollo urbano de las ciudades. Estas tecnologías son una parte actualizada de todas las tecnologías que se pueden aplicar, por tanto es un estado del arte de las nuevas tecnologías aplicadas al desarrollo urbano sustentable, que en su mayoría son procesos, instrumentos de medición, simuladores, equipo, materiales, software y hardware que son de gran ayuda a urbanistas, diseñadores, arquitectos, y promotores del urbanismo en las ciudades.

  5. Neurociencia aplicada: el cerebro al servicio de la humanidad

    Directory of Open Access Journals (Sweden)

    Ángel Correa

    2008-04-01

    Full Text Available La neurociencia aplicada utiliza tecnología y conocimiento sobre el cerebro para resolver problemas prácticos, principalmente en la clínica y el trabajo. La cura de lesiones neurológicas, Parkinson y Alzheimer, podría depender de terapias génicas, neurofeedback, neuroestimulación magnética o implantes neurales. En neuroergonomía, la aplicación de la realidad virtual mejora la productividad y la seguridad laboral.

  6. Neurociencia aplicada: el cerebro al servicio de la humanidad

    OpenAIRE

    Ángel Correa

    2008-01-01

    La neurociencia aplicada utiliza tecnología y conocimiento sobre el cerebro para resolver problemas prácticos, principalmente en la clínica y el trabajo. La cura de lesiones neurológicas, Parkinson y Alzheimer, podría depender de terapias génicas, neurofeedback, neuroestimulación magnética o implantes neurales. En neuroergonomía, la aplicación de la realidad virtual mejora la productividad y la seguridad laboral.

  7. Tendencia de I+D+i en Biomecánica aplicada al deporte

    OpenAIRE

    Ferro Sanchez, Amelia

    2012-01-01

    Análisis de la investigación en el ámbito de la Biomecánica aplicada al deporte. La tendencia de los proyectos en I+D+i de la Biomecánica del Deporte ha cambiado notablemente en las dos últimas décadas. Los investigadores han pasado de aplicar la biomecánica al alto rendimiento deportivo a tratar temas transversales, relacionados en muchos casos con la salud, fisiología, rehabilitación, el control motor, la gestión y, entre otros, el diseño de equipamiento e instalaciones.

  8. Geometría aplicada al dibujo de la arquitectura tratamiento pedagógico

    OpenAIRE

    1994-01-01

    Estructuración de las materias de Geometría, Dibujo y Análisis Arquitectónico con un planteamiento pedagógico, para potenciar en la docencia universitaria la asimilación comprensiva, la creatividad aplicada y la autonomía personal, y una finalida ... Plantea estructuración de las tres materias nuevas, vinculadas con la práctica docente, que involucre al alumnado en el proceso desde una perspectiva didáctica con los objetivos de encontrar las claves de estructuración en la propia materia, logr...

  9. Tecnología y filosofía wiki aplicadas al electromagnetismo computacional

    OpenAIRE

    De la Cruz Calvo, Daniel

    2007-01-01

    Este trabajo de fin de carrera se ha realizado en la Escola Politècnica Superior de Castelldefels (EPSC) en colaboración con el Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE) con el objetivo de explorar las posibilidades de la tecnología wiki aplicada al ámbito de investigación de CIMNE: el electromagnetismo computacional. De acuerdo con la Wikipedia, “un (o una) wiki es un sitio web colaborativo que puede ser editado por varios usuarios. Los usuarios de una ...

  10. Herramientas de manufactura esbelta aplicadas al desarrollo de software con calidad

    OpenAIRE

    2011-01-01

    El artículo presenta una propuesta de herramientas de manufactura esbelta aplicadas al desarrollo de software, dentro del marco de métodos ágiles, en particular el Desarrollo de Software Esbelto; lo que permitirá a equipos de desarrollo obtener una calidad sistémica del software (producto, procesos y personas que intervienen). Se recomienda emplear estas herramientas y evaluarlas constantemente con la aplicación iterativa e incremental del ciclo de calidad propuesto por Deming: planificar, ha...

  11. Tolerancia al co en celdas de combustible

    Directory of Open Access Journals (Sweden)

    BIBIAN HOYOS

    2008-01-01

    Full Text Available El entendimiento completo del proceso de adsorción y posterior oxidación de moléculas de CO en platino es de fundamental importancia para el desarrollo de celdas de combustible poliméricas que operan a baja temperatura. En este trabajo se presenta una revisión de las cinco estrategias experimentales más importantes en la búsqueda de mejorar la tolerancia al CO: disminución del potencial de inicio de la reacción de oxidación, reducción de la cantidad de CO adsorbido, utilización de pequeñas cantidades de oxígeno en la corriente de alimentación al ánodo, aumento de la temperatura de operación y limpieza del CO a la entrada. Aunque se han desarrollado catalizadores bastante promisorios (PtMo y PdAu, todavía se sigue considerando a la mezcla Pt-Ru como el catalizador anódico más eficiente para combustibles que contienen 10 ppm de CO o más. La estrategia de inyectar oxígeno al ánodo parece promisoria pero requiere el desarrollo de nuevas membranas más resistentes y de la implementación de condiciones más seguras de operación de la celda. El diseño estructural de ánodos especiales con múltiples capas soportando catalizadores específicos para cada tipo de combustible puede ser una estrategia muy atractiva.

  12. Mechanism and kinetics analysis of AlN combustion synthesis

    Institute of Scientific and Technical Information of China (English)

    郑永挺; 张宇民; 赫晓东; 刘长青

    2004-01-01

    Mechanism of AlN combustion synthesis was studied by DSC analysis and "quenching" experiment of combustion wave. In preheating region, Al powder melted at 660 ℃ and became spherical because of surface tension. In reaction region, Al volatilized rapidly at 1 000 ℃ and Al vapor reacted with N2 to form AlN, which nucleated and grew on the surface of AlN formed precedently as a diluent. Based on the experiment analysis,kinetics equations and modeling were established. Analysis showed the dramatic effect of temperature, aluminum particle size and nitrogen pressure on the reaction speed.

  13. Quimiometría aplicada al control de calidad de fármacos

    OpenAIRE

    SALAZAR, MARÍA DE LA LUZ; LÓPEZ DE ALBA, PEDRO L.; Piñeyro López, Alfredo.; Waksman de Torres, Noemí

    2003-01-01

    Las técnicas empleadas para el control de calidad de la Peroxisomicina A1, fueron mejoradas aplicando técnicas quimiométricas tanto en CLAR como en espectrofotometría UV-visible. El uso de cromatogramas derivados en CLAR, permitió resolver la señal de un contaminante con tiempo de retención cercano al de la PA1 y de esta manera se mejoraron los parámetros de cuantificación del mismo. Por UV-visible se realizó la cuantificación del contaminante empleando dos técnicas...

  14. Estrategias de genética reversa aplicadas al vesivirus de conejo

    OpenAIRE

    García Manso, Alberto

    2016-01-01

    En el ámbito de la Virología, se denomina genética reversa al proceso de rescate de virus RNA de novo a partir de una copia del genoma viral en forma de cDNA. El trabajo recogido en esta memoria de tesis doctoral se ha dirigido a la obtención de un sistema de genética reversa para el vesivirus de conejo (RaV), uno de los pocos calicivirus capaz de ser propagado en cultivos celulares. Para ello, se han utilizado diferentes estrategias para expresar distintos clones de cDNA sintetizados. En ...

  15. Optimización matemática aplicada al análisis de riesgos

    OpenAIRE

    Bernechea, Esteban

    2010-01-01

    Durante las últimas decadas, la tendencia continuada de la industria de procesos químicos, con respecto a la seguridad industrial, ha sido la de invertir grandes cantidades de dinero, con el fin de mejorar este aspecto. Esto se ha debido, en gran parte, a la ocurrencia de varios accidentes graves durante la década de 1980 (y algunos más recientemente), lo que aunado al cambio de percepción de las sociedades más prósperas hacia la industria de procesos, que es vista cada vez más...

  16. Dinámica de fluidos computacional aplicada al estudio de regeneradores térmicos

    Directory of Open Access Journals (Sweden)

    Cesar Nieto Lodoño

    2004-01-01

    Full Text Available En el presente artículo, muestra los resultados logrados durante la simulación de un regenerador térmico de lecho poroso empacado, sometido a convección forzada transitoria y su respectiva verificación experimental. Para visualizar la aplicación de la Dinámica de Fluidos Computacional (en inglés Computational Fluid Dynamics, CFD en regeneradores de calor, se realiza un estudio detallado de los elementos que conforman la malla; analizando su distribución, tamaño y respectivo efecto sobre la precisión de los resultados. Se establecen las simplificaciones y alcances de los modelos empleados. Se comprueba la veracidad de los resultados obtenidos, mediante la validación experimental de estos en un modelo físico idéntico al empleado durante la simulación. Estas etapas permitieron observar que el comportamiento exponencial de la temperatura en los elementos empacados durante el periodo de calentamiento, fue idéntico al observado por Mejía [8]. Los resultados obtenidos aquí, verifican la capacidad de la CFD para el estudio de los regeneradores térmicos.

  17. Arqueología virtual aplicada al sitio Villavil, Catamarca, Argentina

    Directory of Open Access Journals (Sweden)

    Julieta Lynch

    2014-10-01

    Full Text Available En este trabajo se presenta los resultados de los trabajos de relevamiento realizados en el sitio arqueológico Villavil. El mismo se encuentra en la región norte del valle de Hualfín, Catamarca, Argentina. Esta región estuvo habitada por poblaciones humanas desde tiempos tempranos hasta la llegada incaica y la posterior conquista española. A partir del registro del sitio con estación total se aplicaron programas de realidad virtual con el fin de proporcionar un conjunto más completo de datos al momento de la interpretación de la funcionalidad intrasitio, para momentos previos y posteriores a la llegada incaica en esta región del Noroeste Argentino.

  18. BIOLOGÍA MOLECULAR APLICADA AL DIAGNÓSTICO CLÍNICO

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    BQ. MAURICIO J. Farfán, PhD

    2015-11-01

    Full Text Available El diagnóstico molecular es una área dinámica en constante desarrollo que ha revolucionado el diagnóstico clínico. La detección y cuantificación específica de material genético en una muestra biológica ha mostrado un significativo impacto en todas las áreas de la salud, sobre todo en las áreas de las enfermedades infecciosas y el cáncer. El desarrollo de nuevas tecnologías, más rápidas y precisas, ha transformado al diagnóstico molecular en una herramienta clave para el equipo clínico en directo beneficio del paciente. Esta revisión se enfoca en el impacto de la biología molecular en el diagnóstico, describiendo algunos aspectos históricos, las principales técnicas utilizadas y sus proyecciones.

  19. La política financiera y bancaria aplicada al proceso de apertura y su incidencia en la producción nacional

    Directory of Open Access Journals (Sweden)

    Alberto Ortíz Gómez

    2015-05-01

    Full Text Available RESUMEN Este artículo se basa a partir de un debate realizado el 11 de octubre por el Dr Alberto Ortiz  Gómez en el VIII Encuentro  Nacional  de  Administradores de Empresas y II  Binacional  Colombo- Venezolano, celebrado en Cúcuta, la ponencia titulada  “La Política Financiera y Bancaria aplicada al proceso de Apertura  en la producción Nacional¨. No obstante  por considerar este trabajo un valioso aporte se publicó en esta edición la primera parte de esta.

  20. Descripción matemática de la función gompertz aplicada al crecimiento de animales

    Directory of Open Access Journals (Sweden)

    C. Manrique

    2010-04-01

    Full Text Available Desde su aparición en 1825, la curva sigmoidea propuesta por Benjamin Gompertzha sido aplicada en diferentes campos. En ciencias animales se usa frecuentementepara describir el crecimiento de los individuos. En el presente trabajo se muestra unanálisis matemático de la función y la construcción de algunos de los parámetros quese obtienen de la misma.

  1. DESCRIPCIÓN MATEMÁTICA DE LA FUNCIÓN GOMPERTZ APLICADA AL CRECIMIENTO DE ANIMALES

    Directory of Open Access Journals (Sweden)

    C. A. Martínez

    2010-01-01

    Full Text Available Desde su aparición en 1825, la curva sigmoidea propuesta por Benjamin Gompertz ha sido aplicada en diferentes campos. En ciencias animales se usa frecuentemente para describir el crecimiento de los individuos. En el presente trabajo se muestra un análisis matemático de la función y la construcción de algunos de los parámetros que se obtienen de la misma.

  2. Descripción matemática de la función gompertz aplicada al crecimiento de animales

    OpenAIRE

    2010-01-01

    Desde su aparición en 1825, la curva sigmoidea propuesta por Benjamin Gompertzha sido aplicada en diferentes campos. En ciencias animales se usa frecuentementepara describir el crecimiento de los individuos. En el presente trabajo se muestra unanálisis matemático de la función y la construcción de algunos de los parámetros quese obtienen de la misma.

  3. Descripción matemática de la función gompertz aplicada al crecimiento de animales

    OpenAIRE

    2010-01-01

    Desde su aparición en 1825, la curva sigmoidea propuesta por Benjamin Gompertz ha sido aplicada en diferentes campos. En ciencias animales se usa frecuentemente para describir el crecimiento de los individuos. En el presente trabajo se muestra un análisis matemático de la función y la construcción de algunos de los parámetros que se obtienen de la misma.

  4. Aproximación al léxico de la ciencia aplicada en el Renacimiento hispano

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    Mancho Duque, M.ª J.

    2003-12-01

    Full Text Available In this study we analyze the appearance of technical vocabulary during the spanish Renaissance. Some of the main linguistic characteristics are taken into account from various levels: phonetics, morphology and semantics, with a series of specific examples. Several examples of loanwords are studied from either classic or modern language, chosen from the most prestigious languages of the time.

    En este trabajo se enfoca el surgimiento del vocabulario especializado en el campo de la ciencia aplicada durante el período del renacimiento español. Se analizan algunas de las principales características desde los planos gráfico-fonético, morfológico y semántico, de las que se aportan ejemplos concretos, y se recogen testimonios de préstamos procedentes, tanto de lenguas clásicas, como de otras de prestigio cultural en la época.

  5. Métodos y usos agrícolas de la ingeniería genética aplicada al cultivo de arroz

    OpenAIRE

    Cristina DiazGranados D.; Alejandro Chaparro-Giraldo

    2012-01-01

    Methods and agricultural uses of genetic engineering applied to rice crop Resumen: En biotecnología de arroz se han logrado avances en transformación genética, con importantes resultados en el mejoramiento genético de variedades elite de las subespecies japónica e índica. Con el propósito de revisar los métodos y los usos agrícolas de la ingeniería genética aplicada al cultivo del arroz, se usaron varias palabras claves en idioma inglés en algunas de las bases de datos de revistas científicas...

  6. El futuro de las tecnologías digitales aplicadas al aprendizaje de personas con necesidades educativas especiales

    Directory of Open Access Journals (Sweden)

    Carlos de Castro Lozano

    2012-01-01

    Full Text Available Se presentan en este trabajo las tendencias de las tecnologías digitales aplicadas a los sistemas de aprendizaje, haciendo especial hincapié en aquellas que favorecen la inclusión de las personas con necesidades educativas especiales. A modo de introducción, se resume la evolución de estas tecnologías, y a continuación, se desarrolla una nueva concepción del aprendizaje en línea y un modelo de innovación basado en el concepto de aprendizaje invisible y en los sistemas ubicuos de aprendizaje. Se define una plataforma de Aprendizaje digital, integrando una serie e-Servicios y Tecnologías de Apoyo, que es un ecosistema de aprendizaje en línea, interactivo, inteligente, inclusivo, accesible, usable, ubicuo, adaptativo, multimodal y diseñado para Todos. Este sistema actúa como elemento facilitador de la interacción entre el usuario y los objetos y actividades de aprendizaje, teniendo en cuenta que el público objetivo son las personas con diversidad y aquellas que nunca han utilizado las tecnologías digitales por miedo (tecnofobia o porque no le hayan sido accesibles o asequibles.

  7. Ni-Al and NiO-Al Composite Coatings by Combustion-Assisted Flame Spraying

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    Galina Xanthopoulou

    2014-04-01

    Full Text Available A new, cost-efficient and on-site-applicable thermal spraying process for depositing NiAl metallic overlay or bond-coat coatings for high temperature applications by synthesizing the desired intermetallic phases in-flight during oxy-acetylene flame spraying is presented. Base-metal powders were used for spraying and, by adjusting the spraying conditions, excellent NiAl-based coatings were achieved on various substrates, including mild steel, stainless steel and aluminium alloys. Expensive, pre-alloyed or agglomerated powders are avoided and the method is very promising for in-situ work and repairs. We call the new method “Combustion-Assisted Flame Spraying” (CAFSY and its viability has been demonstrated at a pre-industrial level for coating metallic substrates. The NiAl-based coatings produced by CAFSY exhibit very high integrity with good adhesion, very low porosity, high surface hardness and high erosion resistance at a substantially lower cost than equivalent coatings using pre-prepared alloy powders.

  8. La introducción de la genética en México: la genética aplicada al mejoramiento vegetal

    Directory of Open Access Journals (Sweden)

    Gaona Robles, Ana Lilia

    2001-12-01

    Full Text Available The aim of this paper is to deal with the introduction, sensu Conry, of genetics in Mexico. In the XIX Century the medical community was one of the most prominent groups that developed the field of «heredity», although they never used the genetical principles in their field. We will try to show that one of the main events in the history of genetics in Mexico deals with the introduction of techniques, rather than theories. The research in genetics began through one of the most practical applications, experimental genetics applied to the improvement of species with economical interests.

    El objetivo de este artículo es estudiar la introducción, sensu Conry, de la genética en México. Para ello, hablaremos de la comunidad médica del XIX, la que desarrolló los principios fundamentales de la «herencia», sin aplicar los principios elementales de la genética. Trataremos de mostrar cómo los principios genéticos fueron introducidos vía las técnicas y no vía la teoría. La investigación genética en México comenzó a través de sus aspectos más prácticos, la genética experimental aplicada al mejoramiento de las especies con intereses económicos.

  9. La hermenéutica como corriente aplicada al campo de la educación de la enfermería

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    Elena Mora-Escalante

    2015-01-01

    Full Text Available El artículo científico titulado la hermenéutica como corriente aplicada al campo de la educación de la enfermería, tiene como fin reflexionar sobre el reto que representa para el profesorado de la Escuela de Enfermería de la Universidad de Costa Rica mediar la propuesta curricular acorde con el paradigma asumido. Se plantea la forma de entender el proceso formativo desde el paradigma hermenéutico, donde la educación es comprendida como un proceso íntimo de formación de la persona desde una perspectiva holística. Se propone una pedagogía abierta a la experiencia, vivencia y comprensión de los sujetos, los cuales son los actores y el centro del proceso y que como sujeto histórico, subjetivo, inter e intra-subjetivo, busca el diálogo para construir el conocimiento que se gesta en lo social y es asimilado y transformado en lo individual. Esto implica un compromiso del profesorado para comprender el fundamento paradigmático de la propuesta curricular y desarrollar una pedagogía hermenéutica.

  10. Estrategias pedagógicas aplicadas al desarrollo de competencias ciudadanas en jóvenes universitarios

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    Esnares Maussa Diaz

    2015-01-01

    Full Text Available El presente estudio se ha derivado de una investigación educativa orientada al diseño de estrategias para el desarrollo de competencias ciu- dadana de los estudiantes en jóvenes universitarios. El abordaje metodo- lógico se asumió desde el Paradigma de Investigación Holística, con un diseño mixto en una muestra de 215 jóvenes universitarios de las asigna- turas Constitución Política, Ética y Taller de Pensamiento. Los hallazgos resaltan la importancia que los estudiantes brindan a los procesos de for- mación de cultura política, en contextos curriculares interdisciplinarios orientados al fortalecimiento del compromiso ciudadano en la construc- ción de una cultura de participación, convivencia y paz.

  11. Combustion Synthesis and Densification of NiAl/TiB2 Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A suitable combustion synthesis and densification process was designed to fabricate dense NiAl/TiB2 composites from Ni-Al-Ti-B system. Combustion synthesis processing and microstructure characteristics of products were studied in detail.The results show that the amount of TiB2 ceramics has a great influence on the combustion synthesis processing and microstructure; with the increase of the amount of TiB2 ceramics, the combustion temperature and combustion velocity increase rapidly.The volume of synthesized products and the grain size of ceramics particle size are also affected by the amount of TiB2 ceramics.TiB2 ceramics fiber can be produced in this synthesis system.The dense NiAl/TiB2 composites with residual porosity of no more than 1% are fabricated by the combustion synthesis and hot pressing,the mechanical properties of the dense NiAl/TiB2 composites increase with increase of the amount of TiB2 ceramics.

  12. Administración policial. Administración pública aplicada al manejo de policías

    OpenAIRE

    Luis Villalobos García

    2009-01-01

    El presente trabajo busca vincular los procesos propios de la administración pública al manejo de las organizaciones de policía. Parte de considerar que la función policial históricamente ha carecido de la formalización tanto de sus aspectos administrativos como de la sistematización del conocimiento que genera el desempeño policial, lo cual no ha permitido articular y aprovechar la experiencia adquirida y posteriormente generar referentes consolidados para la gestión del trabajo de las poli...

  13. Administración policial. Administración pública aplicada al manejo de policías

    Directory of Open Access Journals (Sweden)

    Luis Villalobos García

    2009-01-01

    Full Text Available El presente trabajo busca vincular los procesos propios de la administración pública al manejo de las organizaciones de policía. Parte de considerar que la función policial históricamente ha carecido de la formalización tanto de sus aspectos administrativos como de la sistematización del conocimiento que genera el desempeño policial, lo cual no ha permitido articular y aprovechar la experiencia adquirida y posteriormente generar referentes consolidados para la gestión del trabajo de las policías, a partir de este contexto, se presentan propuestas de definición de conceptos y procedimientos correspondientes a una administración policial.

  14. La transparencia de las administraciones públicas aplicadas al derecho a la documentación

    OpenAIRE

    Magdalena Suárez Ojeda

    2015-01-01

    El Derecho Administrativo de la Documentación figura en primera línea del debate  democrático actual. La aprobación de la Ley 19/2013, de 9 de diciembre, de transparencia, acceso a la información pública y buen gobierno se nos presenta como fruto tardío de una regulación que no llegaba nunca, a pesar de que en el entorno jurídico de referencia se había abordado en muchas ocasiones hacía décadas. Los constantes casos de corrupción siguieron toda su tramitación parlamentaria y continúan al día ...

  15. 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

  16. Planificación forestal estratégica con criterios múltiples aplicada al contexto cubano.

    Directory of Open Access Journals (Sweden)

    M. A. León

    2005-01-01

    Full Text Available En este trabajo se resuelve un problema de planificación forestal a través de un modelo de programación por metas fraccional. El problema está situado en Cuba, donde, debido a las particulares características de la isla, los bosques presentan una distribución por edades bastante irregular. Por este motivo, uno de los objetivos del modelo es alcanzar una redistribución por edades homogénea de la masa arbórea. Esto ha sido formalizado en el modelo mediante metas fraccionales, las cuales aseguran el equilibrio por edades del rodal al finalizar el horizonte temporal. Ahora bien, el modelo planteado no sólo se centra en el objetivo mencionado, sino que además incorpora otros aspectos de tipo económico y ecológico. El modelo ha sido aplicado a una plantación cubana perteneciente a la Empresa Forestal Integral de Pinar del Río.

  17. La investigación cualitativa aplicada al estudio del nacionalismo: el discurso neoespañolista

    Directory of Open Access Journals (Sweden)

    HELENA BÉJAR

    2007-01-01

    Full Text Available El siguiente artículo es parte de una investigación cualitativa de diecisiete grupos sobre «Nacionalismo y sentido de pertenencia: nacionalismo español, catalán y vasco». Se analiza aquí lo que llamo discurso neoespañolista, caracterizado por establecer una crítica del nacionalismo tanto en su versión españolista como en la de las naciones sin Estado y la apertura a un discurso cívico-republicano. Dicho discurso reivindica la noción de ciudadanía frente a la de pertenencia, propia del lenguaje político nacionalista. El artículo se aproxima, en primer lugar, a la concepción que los participantes en cinco grupos de discusión ofrecen sobre la comprensión de España como Estado, no como nación, enmarcando dicha concepción a lo largo de las últimas décadas. En segundo lugar se estudian los sentidos que se dan a la identidad española. En tercer y último lugar se analizan las formas de contestación política que se juzgan necesarios frente al progreso del llamado nacionalismo periférico.

  18. Kinetics of Combustion Synthesis in Ti-C-3Ni-Al System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Kinetics and mechanisms of the combustion reaction in the Ti-C-3Ni-Al system were studied. Samples were prepared by igniting compacts of elemental Ti, C, Ni and Al powders with a heating tungsten coil under an inert argon atmosphere. The activation energies of Ti+C+50wt%(3Ni+Al)→TiC+50%Ni3Al and Ti+C+80wt%(3Ni+Al) →TiC+80%Ni3Al exothermic reactions were determined by measuring the combustion wave velocity and the combustion temperature, which are 129kJ.mol-1 and 79kJ*mol-1, respectively. The mechanism of formation of products for Ti-C-3Ni-Al system was found:metal phases (Ti-3Ni-Al) are melted in combustion process,and carbon dissolves into the liquid metal and TiC is subsequently precipitated out of solution, and Ni3Al is crystallized during the cooling process. The mechanism is fairly similar with that of Ti+C→TiC and Ti+C+Ni→TiC+Ni. There are two reactions (Ti+C→TiC, 3Ni+Al→Ni3Al) in the Ti+C+3Ni+Al system, and the wave velocity is mainly controlled by the velocity of Ti + C→TiC, but the velosity of 3Ni+Al→Ni3Al may play a significant role when Ni3Al contents are higher than 70wt%.

  19. Effect of Applied Pressure on the Joining of Combustion Synthesized Ni3Al Intermetallics with Al Alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We focused on the surface reinforcement of ligth weight casting alloys with Ni-Al intermetallic compounds by in-situ combustion reaction to improve the surface properties of non-ferrous casting components. In our previous works, green compact of elemental Ni and Al powders were reacted to form Ni3Al intermetallic compound by SHS (Self-propagating high temperature synthesis) reaction with the heat of molten Al alloy and simultaneously bonded with Al casting alloy. But some defects such as tiny cracks and porosities were remained in the reacted compact. So we applied pressure to prevent thermal cracks and fill up the pores with liquid Al alloy by squeeze casting process. The compressed Al alloy bonded with the Ni3Al intermetallic compound was sectioned and observed by optical microscopy and scanning electron microscopy (SEM). The stoichiometric compositions of the intermetallics formed around the bonded interface and in the reacted compact were identified by energy dispersive spectroscopy (EDS) and electron probe micro analysis (EPMA).Si rich layer was formed on the Al alloy side near the bonded interface by the sequential solidification of Al alloy. The porosities observed in the reacted Ni3Al compact were filled up with the liquid Al alloy. The Si particles from the molten Al alloy were detected in the pores of reacted Ni3Al intermetallic compact. The Al casting alloy and Ni3Al intermetallic compound were joined very soundly by applying pressure to the liquid Al alloy.

  20. Hibridación de metaheurísticas aplicadas al problema de ruteo de vehículos

    Directory of Open Access Journals (Sweden)

    Viviana Beatriz Mercado

    2014-06-01

    Full Text Available El problema de ruteo de vehículos consiste en hallar un conjunto de rutas óptimas de reparto que permitan satisfacer la demanda de clientes. Desde el punto de vista algorít-mico, son problemas de optimización combinatoria de alta complejidad Para esto, se revisa sistemáticamente la literatura generada al respecto en los últimos años respecto a la implementación de algoritmos metaheurísticos que permitan resolver el problema de ruteo de vehículos con capacidad uniforme (Capacitated Vehicle Routing Problems. Identificando los enfoques más exitosos, los esfuerzos de unificación de modelos, así como las proyecciones que existen en este campo y la combinación de métodos de reso-lución aproximados generales (metaheurísticas híbridas permitirá la generación de métodos más exactos y una línea de investigación fructífera. En este trabajo propone-mos un algoritmo para resolver el problema de ruteo de vehículos con capacidad limita-da, utilizando como base un Algoritmo Evolutivo conocido como MCMP-SRI (Stud and Random Inmigrants combinado con conceptos de computación cuántica aplicados a la mutación. Además los resultados son comparados con otros dos algoritmos híbridos que utilizan Hill- Climbing. Detalles de los algoritmos y los resultados de los experimentos muestran un promisorio comportamiento para resolver el problema.

  1. Cadenas de Markov aplicadas al diagnóstico y tratamiento de conductas y procesos de aprendizaje

    Directory of Open Access Journals (Sweden)

    Óscar SAENZ BARRIO

    2009-11-01

    Full Text Available Los paradigmas de investigación educativa se centran fundamentalmente en la determinación de la relación causal entre variables, bien sean éstas uni o multidimensionales, bien concurrentes en el tiempo o distales. En cualquier caso se acepta que las variables causales acontecen antes del evento que producen. Desde un punto de vista teórico, la «covariacion» entre las variables antecedentes y consecuentes sería la evidencia explicativa de la ciencia, y en todo caso permitiría la predictibilidad de un acontecimiento a partir de otro. Sólo si sabemos que hay una relación entre El y E2 podremos hacer previsiones acerca de E2 cuando surja la situación El (Eigenmann, 1981, 29. Desde el punto de vista educativo, la relación entre dos estados (antecedente-consecuente, involucrados en un cambio es muy importante, pero no dice nada en cuanto al proceso de intervención. Puede normar la acción («para conseguir ésto hay que hacer lo otro», pero no prescribe cuándo hay que hacerlo. Dado que la educación es un proceso ordenado en el tiempo, el momento de ejercer las diferentes providencias educativas que configuran conductas, sentimientos, ideales, conocimientos, valores, etc. es uno de los componentes esenciales de su eficacia; lo que hoy podría llamarse optimización de la intervención. Y si ello es cierto para la creación de un aprendizaje cualquiera, lo es más cuando se trata de procesos específicos para reforzar pautas deseables o evitar/eliminar comportamientos indeseables o incorrectos.

  2. Conversión sigma-delta aplicada al control de inversores resonantes; Sigma-Delta Conversion Applied to the Control of the Resonant Inverters

    Directory of Open Access Journals (Sweden)

    Lesyani León Viltre

    2011-02-01

    Full Text Available Se realiza un estudio sobre la conversión sigma-delta aplicada al control de inversores de enlace decontinua resonantes. Este tipo de configuración inversora (inversor resonante con enlace CD es factiblede utilizar como parte integrante de un sistema fotovoltaico de energía porque presenta la ventaja de quetodos los elementos conmutan a tensión o corriente cero, tanto los elementos de alta frecuencia como losque actúan de inversor, sin necesidad de modular la tensión de continua, lo cual simplifica considerablementeel lazo de control. La conversión análoga digital es una etapa clave en la mayoría de los sistemaselectrónicos modernos. Una vez, en formato digital, las señales pueden ser fácilmente almacenadas yprocesadas para obtener la información deseada.  This paper presents an analysis of the sigma-delta conversion applied to the control of the DC linkresonant inverters. This inverter configuration is often employed as a part of photovoltaic system becauseit presents the advantage that the semiconductors elements commute at zero tension or zero current. Ithappen on the high frequency elements and the inverter elements, and it is not necessary to modulate theDC tension, condition that simplified the control loop. Conversion analog-digital is an important step of thealmost every modern electronics systems. After the signal is translated to the digital format, it can beprocessed easily in order to obtain the required information.

  3. Gobernanza Pública y Gobernabilidad: Accountability y Disclosure posibilitadas por la Contabilidad Aplicada al Sector Público como Instrumento de Sostenibilidad del Estado

    Directory of Open Access Journals (Sweden)

    Antonio Gonçalves Oliveira

    2013-03-01

    Full Text Available El Principio de la Continuidad en una visión contable-financiera aplicado a las organizaciones empresariales presupone su sostenibilidad en dirección a la perpetuidad, influenciando y asegurando a los inversores el retorno de sus inversiones. En la Administración Pública, no es diferente, destacándose la existencia del Principio de la Continuidad del Estado. Tal principio describe el Estado como sociedad política que, así como la empresa, debe ser perenne y sostenible visando siempre a la promoción del bien común y al desarrollo de su pueblo. Consonante a la contribución esperada, este trabajo tiene por objetivo discutir la importancia de la Contabilidad Aplicada al Sector Público como herramienta útil a la efectividad de la Gobernanza y de la Gobernabilidad Públicas adherentes a una visión de sostenibilidad aplicable a la gestión del Estado. La metodología adoptada, en relación a los fines, fue la pesquisa exploratoria y explicativa utilizando, en relación a los medios, de investigaciones bibliográficas y documental y de la observación teóricoempírica concernientes a la adherencia de la disclosure (transparencia y de la accountability (responsabilidad social de prestar cuentas a la sociedad a la Gestión Pública. Como resultados fue posible constatar una fuerte interrelación entre los términos, a la vista del hecho de que la Contabilidad evidencie los resultados y las acciones de los gobiernos a partir de la gobernanza (el medio/el cómo relacionada con la gobernabilidad (poder y acciones políticas, y también que ambas son orientadas para la sostenibilidad del Estado. Sobre la sostenibilidad del Estado, fue constatado asimismo que esta es de más alcance que el propio término “sostenibilidad”, el cual, en muchas veces, es reducido a la visión eco-ambiental y no considera importantes variables de cuño financiero (equilibrio y económico-social inherentes a la función social del Estado

  4. Gobernanza Pública y Gobernabilidad: Accountability y Disclosure posibilitadas por la Contabilidad Aplicada al Sector Público como Instrumento de Sostenibilidad del Estado

    Directory of Open Access Journals (Sweden)

    Antonio Gonçalves Oliveira

    2013-01-01

    Full Text Available El Principio de la Continuidad en una visión contable-financiera aplicado a las organizaciones empresariales presupone su sostenibilidad en dirección a la perpetuidad, influenciando y asegurando a los inversores el retorno de sus inversiones. En la Administración Pública, no es diferente, destacándose la existencia del Principio de la Continuidad del Estado. Tal principio describe el Estado como sociedad política que, así como la empresa, debe ser perenne y sostenible visando siempre a la promoción del bien común y al desarrollo de su pueblo. Consonante a la contribución esperada, este trabajo tiene por objetivo discutir la importancia de la Contabilidad Aplicada al Sector Público como herramienta útil a la efectividad de la Gobernanza y de la Gobernabilidad Públicas adherentes a una visión de sostenibilidad aplicable a la gestión del Estado. La metodología adoptada, en relación a los fines, fue la pesquisa exploratoria y explicativa utilizando, en relación a los medios, de investigaciones bibliográficas y documental y de la observación teórico- empírica concernientes a la adherencia de la disclosure (transparencia y de la accountability (responsabilidad social de prestar cuentas a la sociedad a la Gestión Pública. Como resultados fue posible constatar una fuerte interrelación entre los términos, a la vista del hecho de que la Contabilidad evidencie los resultados y las acciones de los gobiernos a partir de la gobernanza (el medio/el cómo relacionada con la gobernabilidad (poder y acciones políticas, y también que ambas son orientadas para la sostenibilidad del Estado. Sobre la sostenibilidad del Estado, fue constatado asimismo que esta es de más alcance que el propio término “sostenibilidad”, el cual, en muchas veces, es reducido a la visión eco-ambiental y no considera importantes variables de cuño financiero (equilibrio y económico-social inherentes a la función social del Estado.

  5. PREPARATION OF CUO/γ-Al2O3 CATALYSTS FOR CATALYTIC COMBUSTION VOCS VIA PLASMA

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    CuO/γ-Al2O3 catalysts were prepared by plasma treatment and conventional impregnation methods. The catalytic combustion of two kinds of volatile organic compounds (VOCs), toluene and benzene, were carried out over these CuO/γ-Al2O3 catalysts. The surface properties of these catalysts were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The experimental results showed that in catalytic combustion the activity of the CuO/γ-Al2O3 catalyst prepared via plasma was much higher than that of the CuO/γ-Al2O3 catalyst prepared by conventional impregnation method. XRD results showed that an enhanced dispersion had been achieved with the plasma treatment. SEM results indicated that the size became much smaller and the surface became more uniform with the plasma treatment.

  6. The Combustion Synthesis Process of Al-Ti-C System in an Elevated-temperature Al-melt

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    One of the main disadvantages of combustion synthesis of ceramic/metal composite materials is the relatively high level of porosity present in the products.To synthesize TiC/Al composites with a dense structure,this paper proposes a novel application of an elevated-temperature Al-melt to directly ignite and simultaneously infiltrate Al-Ti-C preform dipped in the melt.The emphasis was placed on the combustion synthesis process and microstructural evalution of the preform in the melt,by a liquid quenching test combined with the measurement of the temperature history of the dipped preform.The results show that the combustion synthesis process of the preform in the elevated-temperature melt involves a series of reactions,and that higher temperature of the melt is favourable for the formation of TiC.The synthesized TiC/Al composites exhibit a dense structure,which is attributed to the infiltration of the melt into the preform.

  7. Combustion Synthesis of NiAl and In-situ Joining to Ni-based Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Combustion synthesis is used as a joining technology to join Ni-based superalloys with in-situ synthesized NiAl filler. The synthesis mechanism is discussed. The microstructure of the joints is investigated and the joint strength is also evaluated by tensile testing.

  8. Reaction dynamics in the combustion synthesis system of Al-CrO3-Al2O3-NaF-N2-O2

    Institute of Scientific and Technical Information of China (English)

    Dazheng Yang; Yue Zhang; Degang Li; Dianwei Qi; Wei Deng; Dayong Xun

    2007-01-01

    A new material with heat-resistant and adiabatic characteristics and high strength was prepared using the combustion synthesis method by mixed powders of CrO3, Al, Al2O3, and NaF in atmospheric gas. The reaction dynamic process of the Al-CrO3-NaF-Al2O3-N2-O2 new material system by the combustion synthesis method was discussed based on the observation results by SEM,EDS, and XRD in combination with the combustion front quenching method (CFQM) and the relation curves between reaction free enthalpies and the corresponding temperatures. The combustion synthesis mechanism and the formation reasons of the phase in the combustion product were analyzed.

  9. Ultrasound assisted combustion synthesis of TiC in Al-Ti-C system.

    Science.gov (United States)

    Liu, Zhiwei; Rakita, Milan; Xu, Wilson; Wang, Xiaoming; Han, Qingyou

    2015-11-01

    This research investigated the effects of high-intensity ultrasound on the combustion synthesis of TiC particles in Al-Ti-C system. The process involved that high-intensity ultrasound was applied on the surface of a compacted Al-Ti-C pellet directly through a Nb probe during the thermal explosion reaction. By comparing with the sample without ultrasonic treatment, it was found that the thermal explosion reaction for synthesizing TiC phase could take place thoroughly in the ultrasonically treated sample. During the process of synthesizing TiC phase, the dissolution of solid graphite particles into the Al-Ti melt, as well as the nucleation and growth of TiC particles could be promoted effectively due to the effects of ultrasound, leading to an enhancement of the formation of TiC particles. Ultrasound assisted combustion synthesis as a simple and effective approach was proposed for synthesizing materials in this research.

  10. Manufacturing of Porous Al-Cr Preforms for Composite Reinforcing Using Microwave Activated Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Naplocha K.

    2014-10-01

    Full Text Available The combustion synthesis of porous skeletons (preforms of intermetallic Al–Cr compounds intended for metal matrix composite MMC reinforcing was developed. Mixture of Al and Cr powders with granularity of −10, −44, −74mm were cold isostatic pressed and next ignited and synthetized in a microwave reactor under argon atmosphere (microwave-activated combustion synthesis MACS. In order to ignite the synthesis, microwave energy was focused by a tuner on the specimen. The analysis of reaction temperature diagrams revealed that the synthesis proceeded through the following peritectic transformations: L(liquidus+Al7Cr→L+Al11Cr2→L+Al4Cr. Moreover, EDS and XRD examinations showed that the reaction proceeded between a solid Cr and a liquid Al to create a distinct envelope of Al9Cr4 on Cr particle which next extended and spreaded over the entire structure. The produced preforms with uniform structure and interconnected porosity were infiltrated with liquid Cu and Al alloy. The obtained composite materials exhibited high hardness, wear and distinct temperature oxidation resistance.

  11. Métodos y usos agrícolas de la ingeniería genética aplicada al cultivo de arroz

    Directory of Open Access Journals (Sweden)

    Cristina DiazGranados D.

    2012-08-01

    Full Text Available Methods and agricultural uses of genetic engineering applied to rice crop Resumen: En biotecnología de arroz se han logrado avances en transformación genética, con importantes resultados en el mejoramiento genético de variedades elite de las subespecies japónica e índica. Con el propósito de revisar los métodos y los usos agrícolas de la ingeniería genética aplicada al cultivo del arroz, se usaron varias palabras claves en idioma inglés en algunas de las bases de datos de revistas científicas indexadas, disponibles en el Sistema Nacional de Bibliotecas de la Universidad Nacional de Colombia (SINAB, seleccionando documentos publicados entre 2000 y 2011. La base de esta revisión inicial, se complementó con artículos publicados en fechas anteriores, que se consideraron relevantes, debido a que implicaban cambios metodológicos importantes. Desde que se logró producir la primera planta transgénica de arroz a finales de los 80´s, varios protocolos para la transferencia de genes se han empleado con éxito logrando la modificación genética de más de 60 cultivares de arroz. Para ello se han empleado sistemas de transformación tanto directos como indirectos.  Se han realizado modificaciones de rasgos importantes en el cultivo, tales como la resistencia a factores bióticos (insectos, hongos, bacterias, virus, nematodos, tolerancia a factores abióticos (salinidad, sequía, altas y bajas temperaturas, inmersión, y mejoramiento de características agronómicas (calidad nutricional, rendimiento, uso de nutrientes, tolerancia a herbicidas. Palabras claves: Arroz; cultivos transgénicos; factores bióticos; factores abióticos. Abstract: In rice biotechnology advances have been made in genetic transformation, with significant results in breeding elite varieties of japonica and indica subspecies. In order to review the methods and agricultural uses of genetic engineering applied to rice, calves were used several words in English in

  12. Preparation of TiAl/Al2O3 composites by combustion synthesis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Studies the combustion synthesis of A1-Ti-TiO2 system and concludes that,due to its low exothermic nature,a stable combustion wave can be maintained only when the system is ignited at a certain preheating temperature,and coupled with appropriate pseudo-HIP process,dense TiAI/A12 O3 composites with density as high as 97% of the theoretical value can be produced,and points out.Microstructure observation shows in situ formed A12 O3 particles are of an average size smaller than one micron,and the hardness of TiAI matrix is enhanced by introduction of these particles.

  13. In situ synthesis of NiAl-NbB{sub 2} composite powder through combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Shokati, Ali Akbar, E-mail: ali_shokati@aut.ac.ir [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran 1591634311 (Iran, Islamic Republic of); Parvin, Nader, E-mail: nparvin@aut.ac.ir [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran 1591634311 (Iran, Islamic Republic of); Sabzianpour, Naser, E-mail: naser_sabz@yahoo.com [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran 1591634311 (Iran, Islamic Republic of); Shokati, Mohammad, E-mail: mohammad_shokaty14@yahoo.com [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, P.O. Box: 19395-1999, Tehran (Iran, Islamic Republic of); Hemmati, Ali, E-mail: ali19he@gmail.com [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran 1591634311 (Iran, Islamic Republic of)

    2013-02-05

    Highlights: Black-Right-Pointing-Pointer A Novel NiAl matrix composite powder with 0-40 wt.% NbB{sub 2} was synthesized. Black-Right-Pointing-Pointer Composite powders were synthesized by thermal explosion reaction of Ni-Al-Nb-B system. Black-Right-Pointing-Pointer Microhardness of NiAl considerably increased with raising NbB{sub 2} content. Black-Right-Pointing-Pointer Synthesized composite powders is a good candidate as precursor for thermal barrier application. - Abstract: Synthesis of a novel NiAl matrix composite powder reinforced with 0-40 wt.% NbB{sub 2} by combustion synthesis in thermal explosion mode was investigated. The elemental powders of Ni, Al, Nb, and amorphous boron were used as starting material. For all compositions final products consisted of only the NiAl and NbB{sub 2} phases. Coarser NbB{sub 2} with a relatively uniform distribution in NiAl matrix was formed with rising NbB{sub 2} content. Microhardness of NiAl considerably increased from 377 {+-} 13 HV{sub 0.05} to 866 {+-} 81 HV{sub 0.05} for NiAl with 40 wt.% NbB{sub 2}. High microhardness, proper size and distribution of NbB{sub 2} in NiAl matrix make it a good candidate as precursor for thermal spray application.

  14. SrAl2O4:Eu, Dy Nanometer Phosphors Synthesized by Combustion Method

    Institute of Scientific and Technical Information of China (English)

    Qiu Guanming; Sun Yanbin; Zhang Shengqu; Zhang Ming; Yan Changhao; Dai Shaojun

    2004-01-01

    SrAl2 O4: Eu, Dy nanometer phosphors were synthesized by combustion method at 500 ~ 900℃, followed by heating the combustion sample at 1150℃ at a weak reductive atmosphere and nanometer phosphor with much better luminescent properties was obtained. The influences of the initiating combustion temperature, H3BO3 quantity, the mass ratio of urea and nitrate on the luminescent intensity of nanometer phosphors were studied. The optimum synthetic conditions were determined. The analysis results by transmission electron microscopy (TEM) indicate that the particle size of the synthetic product is less than 75 nm. The luminescent materials do not need to be ground. Their coating can be refined. It supplies a new approach to the rapid preparation of the luminescent materials at low temperature. The excitation and emission spectra indicate that the main peaks in the excitation and emission spectrum of nanometer phosphor synthesized by combustion method shifted to the short wavelength compared with the phosphor obtained by the solidstate reaction synthesis method. The reason of blue shift was explained. The afterglow decay results indicate that the decay speed of the afterglow for nanometer phosphor is faster than that obtained by the solid-state reaction method.

  15. Oxidation of Ca-α-SiAlON Powders Prepared by Combustion Synthesis

    Science.gov (United States)

    Li, Jinfu; Li, Zhongmin; Wang, Enhui; Wang, Zhanjun; Yin, Xiaowei; Zhang, Zuotai

    2015-01-01

    The oxidation of Ca-α-SiAlON synthesized by the combustion synthesis (CS) method with different additives was investigated in air atmosphere using thermogravimetric (TG) analysis in a temperature range from 1453 K to 1653 K. The experimental results indicated that oxidation was controlled by mixed chemical and diffusion steps. The oxidation products by XRD analysis were composed of SiO2 and CaAl2Si2O8 at low oxidation temperature, whereas the SiO2-Al2O3-CaO ternary glassy phase was formed at elevated temperature. The deviation of oxidation resistance from each sample may be due to the morphological difference brought about by different additive additions. This study reveals the effects of additives on the oxidation resistance of synthesized Ca-α-SiAlON powders. PMID:28793657

  16. La teoría de los conjuntos-T aplicada al desarrollo de la competencia de modelado matemático

    Directory of Open Access Journals (Sweden)

    RICARDO JOAQUÍN DE ARMAS COSTA

    2016-06-01

    Full Text Available En este artículo queremos dar a conocer apartes de la teoría de los conjuntos-T y cómo se aplica en la educación superior para desarrollar la competencia de modelado matemático de los sujetos. Esta teoría surge como respuesta a los problemas de enseñanza aprendizaje de las matemáticas que se originan en los programas curriculares diseñados para adquirir exclusivamente información y no para desarrollar las competencias matemáticas de los estudiantes. The theory of the Conjuntos-T applied to the development of the competition of mathematical modeling In this article we want to present parts of the theory of joint-T and how it is applied in higher education to develop the competence of mathematical modeling subjects. We explain how the theory can develop the skills of students. This theory is a response to the problems of learning of mathematics that originate in the curriculum designed to acquire information and not only to develop the math skills of students. A teoria de Conjuntos-T aplicada ao desenvolvimento da concorrência  modelagem matemática Neste artigo, nos queremos apresentar algumas noções da teoria dos conjuntos-T e como ela é aplicada na docência, de ensino superior, para desenvolver a competência da modelagem matemática. Nos vamos explicar como a teoria pode desenvolver as habilidades dos alunos. Esta teoria é uma resposta para os problemas de ensino e aprendizagem da matemática que se originam nos programas curriculares destinados a adquirir somente informação e não para desenvolver as habilidades matemáticas dos alunos.

  17. NORMAS BRASILEÑAS E INTERNACIONALES DE CONTABILIDAD APLICADAS AL SECTOR PÚBLICO Y EL DESAFÍO DE LA CONVERGENCIA: UN ANÁLISIS COMPARATIVO – IPSAS Y NBCTSP

    Directory of Open Access Journals (Sweden)

    Adriana Rodrigues Fragoso

    2012-11-01

    Full Text Available El presente estudio tiene por objetivo analizar el estadio actual de convergencia conceptual entre las normas brasileñas de contabilidad aplicadas al sector público (NBCTSP y las International Public Sector Accounting Standard (IPSAS. La complejidad y diversidad de transacciones entre entidades del sector público o privado, generada por la internacionalización de mercados, demandan una evaluación continua y dinámica de los eventos que promueven la modificación cuantitativa o cualitativa de un patrimonio. Para ese proceso de evaluación, la observación de los principios y normas de contabilidad es importante para garantizar, entre otras características de la información, la comprensibilidad y posibilidad de comparación, reduciendo costes a los inversores y usuarios, en general, considerando las barreras encontradas en la diversidad de idiomas, culturas, políticas fiscales y económicas. Para el análisis de convergencia, fue efectuado un estudio comparativo del contenido de las normas, a partir de un análisis descriptivo, con el intuito de verificar la adherencia existente entre las normas brasileñas e internacionales aplicadas al sector público. Los resultados encontrados destacan que todavía hay diversos aspectos a ser discutidos para una efectiva convergencia a las normas internacionales; esta convergencia actual es parcial. No obstante, se verifica que las NBCTSPs presentan una exposición conceptual de calidad mientras que las IPSAS presentan un contenido más enfocado en procedimientos operacionales.

  18. Propane combustion over Pt/Al{sub 2}O{sub 3} catalysts with different crystalline structures of alumina

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Eun; Kim, Bo Bae; Park, Eun Duck [Ajou University, Suwon (Korea, Republic of)

    2015-11-15

    The effects of the crystalline phases (α-Al{sub 2}O{sub 3}, κ-Al{sub 2}O{sub 3}, δ-Al{sub 2}O{sub 3}, θ-Al{sub 2}O{sub 3}, η-Al{sub 2}O{sub 3}, and γ-Al{sub 2}O{sub 3}) of the alumina support of Pt/Al{sub 2}O{sub 3} catalysts on the catalyst activity toward propane combustion were examined. The catalysts were characterized by N{sub 2} physisorption, CO chemisorption, temperature-programmed reduction (TPR), temperature programmed oxidation (TPO), transmission electron microscopy (TEM), and infrared spectroscopy (IR) after CO chemisorption. The Pt dispersion of the catalysts (surface Pt atoms/total Pt atoms), measured via CO chemisorption, was more dependent on the crystalline structure of alumina than on the surface area of alumina. The highest catalytic activity for propane combustion was achieved with Pt/α-Al{sub 2}O{sub 3}, which has the lowest Brunauer, Emmett, and Teller (BET) surface area and Pt dispersion. The lowest catalytic activity for propane combustion was exhibited by Pt/γ-Al{sub 2}O{sub 3}, which has the highest BET surface area and Pt dispersion. The catalytic activity was confirmed to increase with increasing Pt particle size in Pt/δ-Al{sub 2}O{sub 3}. The apparent activation energies for propane combustion over Pt/α-Al{sub 2}O{sub 3}, Pt/κ- Al{sub 2}O{sub 3}, Pt/δ-Al{sub 2}O{sub 3}, Pt/θ-Al{sub 2}O{sub 3}, Pt/η-Al{sub 2}O{sub 3}, and Pt/γ-Al{sub 2}O{sub 3} were determined to be 24.7, 21.4, 24.3, 22.1, 24.0, and 19.1 kcal/mol, respectively.

  19. Combustion Synthesis Reaction Behavior of Cold-Rolled Ni/Al and Ti/Al Multilayers

    Science.gov (United States)

    2011-04-01

    pulse. Such exothermic reactions in multilayers can be used as local heat sources to melt solders or brazes and thus join components in a variety of...4 Figure 1. Schematic of the cold-rolling procedure. diffraction (XRD) examination using Cu Kα radiation. The unreacted as-cold-rolled Ni/Al

  20. EMISIONES AL AIRE DE LA COMBUSTION DE LLANTAS USADAS (SPANISH VERSION)

    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...

  1. EMISIONES AL AIRE DE LA COMBUSTION DE LLANTAS USADAS (SPANISH VERSION)

    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...

  2. Effects of Ce on catalytic combustion of methane over Pd-Pt/Al2O3 catalyst.

    Science.gov (United States)

    Fan, Xing; Wang, Fan; Zhu, Tianle; He, Hong

    2012-01-01

    Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated. The catalysts before and after reaction were characterized by BET, CO chemisorption, XRD and XP S techniques. Results showed that the presence of Ce significantly increased the activity and thermal stability of the Pd-Pt/Al2O3 catalyst towards methane combustion, which could be attributed to more highly-dispersed active PdO particles over the Pd-Pt/Ce/Al2O3 catalyst surface as well as the retarded sintering of PdO and the maintained oxidized state of surface Pd during the combustion process in the presence of Ce.

  3. Effects of Ce on catalytic combustion of methane over Pd-Pt/Al2O3 catalyst

    Institute of Scientific and Technical Information of China (English)

    Xing Fan; Fan Wang; Tianle Zhu; Hong He

    2012-01-01

    Activity and stability of 1%Pd-0.2%Pt/Al2O3 and 1%Pd-0.2%Pt/0.6%Ce/Al2O3 catalysts prepared by impregnation method for catalytic combustion of methane in air were investigated.The catalysts before and after reaction were characterized by BET,CO chemisorption,XRD and XPS techniques.Results showed that the presence of Ce significantly increased the activity and thermal stability of the Pd-Pt/Al2O3 catalyst towards methane combustion,which could be attributed to more highly-dispersed active PdO particles over the Pd-Pt/Ce/Al2O3 catalyst surface as well as the retarded sintering of PdO and the maintained oxidized state of surface Pd during the combustion process in the presence of Ce.

  4. Preparation of porous Al2O3-Ti-C perform by combustion synthesis

    Directory of Open Access Journals (Sweden)

    K.Granat

    2009-04-01

    Full Text Available Using combustion synthesis porous ceramic preforms for composite reinforcing were produced. Prepared mixture of alumina Saffilfibres, Ti powder and graphite flakes, after drying were placed in waveguide of microwave reactor. Supplied with constant power of 540Wmagnetron ignited and maintained reaction in flowing stream of CO2 gas. Al2O3 fibres should improve preliminary endurance of perform,whereas Ti powder processed to hard titanium carbides and oxides. During microwave heating ignited plasma additionally improveprocess and partly fused metallic Ti. Recorded temperature curves were similar for various samples. The highest synthesis temperature revealed samples containing 10% of Al2O3 , 10% of Ti and 5% of graphite, all percentages atomic. Microscopic observation showed considerable microstructure inhomogeneity of some samples. Both irregular component ordering and partly processed Ti particles inside preform exclude them for subsequent infiltration. Chemical analyze EDS of Ti based compounds partly confirmed work purpose, evidencing presence of Ti oxides and carbides. Independently of graphite content these compounds formed folded strips around solid or empty volume. Depends on CO2 availability, reaction could be slowed down resulting in more compacted Ti compounds. Created as a result of combustion synthesis Ti compound after infiltration with liquid metal properly bounded with the matrix. It could be assumed that redox reaction proceeded and on surface of Ti compound alumina and Al-Ti compounds were created. The preforms of proper strength and homogeneous structure were infiltrated with AlSi7Mg by squeeze casting method. In relation to typical composite reinforced only with fibres no significant increase of defects quantity was observed. Preliminary examination of mechanical properties confirmed that assumed work purpose is reasonable.

  5. Mechanoluminescence properties of SrAl2O4:Eu(2+) phosphor by combustion synthesis.

    Science.gov (United States)

    Bisen, D P; Sharma, R

    2016-03-01

    In this paper, europium-doped strontium aluminate (SrAl2O4:Eu(2+)) phosphors were synthesized using a combustion method with urea as a fuel at 600°C. The phase structure, particle size, surface morphology and elemental analysis were studied using X-ray diffractometry (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared (FTIR) spectra. The EDX and FTIR spectra confirm the elements present in the SrAl2O4:Eu(2+) phosphor. The optical properties of SrAl2O4:Eu(2+) phosphors were investigated by photoluminescence (PL) and mechanoluminescence (ML). The excitation and emission spectra showed a broad band with peaks at 337 and 515 nm, respectively. The ML intensities of SrAl2O4:Eu(2+) phosphor increased proportionally with the increase in the height of the mechanical load, which suggests that this phosphor could be used in stress sensors. The CIE colour chromaticity diagram and ML spectra confirm that the SrAl2O4:Eu(2+) phosphor emitted green coloured light.

  6. Aplicación del modelo Casi Ideal de Demanda al mercado de combustibles en el sector transporte en Colombia

    OpenAIRE

    Orrego Pemberty, Marcela; Castaño Duque, John Mauro,

    2015-01-01

    El presente trabajo constituye una aproximación a un mejor entendimiento del comportamiento de la demanda de combustibles del sector transporte a nivel nacional, resaltando la recomposición que se ha venido presentando en el mercado durante los últimos años -- Para ello, se aplica el Modelo Casi Ideal de Demanda (AIDS) al mercado de combustibles en Colombia, empleando información mensual correspondiente al periodo 2003–2012, con el fin de determinar las elasticidades precio de la demanda, pre...

  7. Electrical and optical properties of NdAlO{sub 3} synthesized by an optimized combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Midhun [Department of Physics, University College, University of Kerala, Trivandrum 695 101 (India); Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, 26300 Kuantan, Pahang (Malaysia); Nair, V. Manikantan; Wariar, P.R.S. [Department of Physics, University College, University of Kerala, Trivandrum 695 101 (India); Padmasree, K.P. [CINVESTAV, Saltillo (Mexico); Yusoff, Mashitah M. [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, 26300 Kuantan, Pahang (Malaysia); Central Laboratory, Universiti Malaysia Pahang (Malaysia); Jose, Rajan, E-mail: rjose@ump.edu.my [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, 26300 Kuantan, Pahang (Malaysia)

    2014-04-01

    Nanocrystals of neodymium aluminate (NdAlO{sub 3}) are synthesized using an optimized single step auto-ignition citrate complex combustion process. The combustion product was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and Ultraviolet–visible reflection spectroscopy. The combustion product is single phase and composed of aggregates of nanocrystals of sizes in the range 20–40 nm. The NdAlO{sub 3} crystallized in rhombohedral perovskite structure with lattice parameters a = 5.3223 Å and c = 12.9292 Å. The absorption spectrum of the NdAlO{sub 3} nanocrystals shows characteristic absorption bands of the Nd atom. The polycrystalline fluffy combustion product is sintered to high density (∼ 97%) at ∼ 1450 °C for 4 h and the microstructure was characterized by scanning electron microscopy. The electrical properties of the sintered product were studied using dielectric measurements. The sintered NdAlO{sub 3} has a dielectric constant (ε{sub r}) and a dielectric loss (tan δ) of 21.9 and ∼ 10{sup −3} at 5 MHz, respectively. - Highlights: • NdAlO{sub 3} nanocrystals were synthesized through a citrate combustion process. • The nanocrystals were sintered to ∼ 97% of theoretical density. • The materials were characterized using a number of analytical techniques. • Nanostructured NdAlO{sub 3} showed crystal field splitting of Nd ions. • Dielectric properties of the sintered NdAlO{sub 3} ceramics were studied.

  8. Auto-combustion synthesis and characterization of Mg doped CuAlO2 nanoparticles

    Science.gov (United States)

    Agrawal, Shraddha; Parveen, Azra; Naqvi, A. H.

    2015-06-01

    The synthesis of pure and Mg doped Copper aluminumoxide CuAlO2nanoparticles, a promising p-type TCO (transparent conducting oxide) have been done bysol gel auto combustion method using NaOH as a fuel, calcinated at 600°C. The structural properties were examined by XRD and SEM techniques. The optical absorption spectra of CuAlO2 sample recorded by UV-VIS spectrophotometer in the range of 200 to 800 nm have been presented. The crystallite size was determined by powder X-ray diffraction technique. The electrical behavior of pure and Mg doped CuAlO2 has been studied over a wide range of frequencies by using complex impedance spectroscopy.The variation of a.c. conductivity has been studied as function of frequency and temperature. The data taken together conclude that doping causes decreases in the ac conductivity of the nanoparticles as compared with the pure nanoparticles. Mg doping affects the optical properties and band gap.

  9. Auto-combustion synthesis and characterization of Mg doped CuAlO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Shraddha, E-mail: shraddhaa32@gmail.com; Parveen, Azra; Naqvi, A. H. [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Z.H. College of Engg.& Technology, Aligarh Muslim University, Aligarh-202002 (India)

    2015-06-24

    The synthesis of pure and Mg doped Copper aluminumoxide CuAlO{sub 2}nanoparticles, a promising p-type TCO (transparent conducting oxide) have been done bysol gel auto combustion method using NaOH as a fuel, calcinated at 600°C. The structural properties were examined by XRD and SEM techniques. The optical absorption spectra of CuAlO{sub 2} sample recorded by UV-VIS spectrophotometer in the range of 200 to 800 nm have been presented. The crystallite size was determined by powder X-ray diffraction technique. The electrical behavior of pure and Mg doped CuAlO{sub 2} has been studied over a wide range of frequencies by using complex impedance spectroscopy.The variation of a.c. conductivity has been studied as function of frequency and temperature. The data taken together conclude that doping causes decreases in the ac conductivity of the nanoparticles as compared with the pure nanoparticles. Mg doping affects the optical properties and band gap.

  10. Corrosion of combustion-synthesized {beta}-SiAlONs in supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Yi Xuemei [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan); Yamauchi, Akira; Kurokawa, Kazuya [Center for Advanced Research of Energy and Materials, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan); Akiyama, Tomohiro, E-mail: takiyama@eng.hokudai.ac.jp [Center for Advanced Research of Energy and Materials, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer The corrosion of {beta}-Si{sub 6-z}Al{sub z}O{sub z}N{sub 8-z}s (z = 1, 2, and 3) has been investigated in SCW under 400 Degree-Sign C/35 MPa for 100 h. Black-Right-Pointing-Pointer The corrosion behavior of these materials is studied using XRD, SEM, and EDS. Black-Right-Pointing-Pointer The reaction mechanism of {beta}-Si{sub 6-z}Al{sub z}O{sub z}N{sub 8-z}s in supercritical water is proposed. Black-Right-Pointing-Pointer The results in this study could present a valuable example for similar studies. - Abstract: The corrosion of {beta}-Si{sub 6-z}Al{sub z}O{sub z}N{sub 8-z}s (z = 1, 2, and 3) prepared by combustion synthesis (CS) followed by spark plasma sintering (SPS) was investigated in supercritical water at 400 Degree-Sign C/30 MPa for 100 h. The corrosion behavior was studied by means of gravimetry, X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS). The mass loss and corroded layer decreased with the increasing in z value, and the results of XRD showed the oxide formed on {beta}-SiAlONs (z = 1, 2, and 3) is aluminum silicate (Al{sub 2}SiO{sub 5}). Finally, we proposed the reaction mechanism of these materials in supercritical water.

  11. Hydrogen Generation from Ammonia Borane and Water Through the Combustion Reactions with Mechanically Alloyed Al/Mg Powder

    Science.gov (United States)

    2014-08-11

    synthesis of ammonia -A ‘‘never ending story? " Angewandte...34 # && , (/ -%(/ &$’$) ) ! -( ( !( &" # ( %’ !&% # ’)( (% (" %’% (" ( & *%" # ’)( *! % + 3 HYDROGEN GENERATION FROM AMMONIA BORANE AND WATER THROUGH THE...FROM AMMONIA BORANE AND WATER THROUGH THE COMBUSTION REACTIONS WITH MECHANICALLY ALLOYED AL/MG POWDER by DANIEL RODRIGUEZ THESIS Presented to

  12. Mechanoluminescence by Impulsive Deformation and Photoluminescence of SrAl2O4:Eu Phosphor Prepared by Combustion Synthesis

    Science.gov (United States)

    Choubey, Anil Kumar; Brahme, Nameeta; Bisen, D. P.

    SrAl2O4: Eu was synthesized by combustion method. Mechanoluminescence (ML) and Photoluminescence (PL) were studied. Time vs ML intensity plot shows two peaks. ML intensity increases with load applied and it is regained by UV irradiation. Photoluminescence shows intense emission in green region. PACS: 78.60.Mq; 78.55.Hx

  13. Hydrogen generation from ammonia borane and water through the combustion reactions with mechanically alloyed Al/Mg powder

    Science.gov (United States)

    Rodriguez, Daniel

    Finding and developing a safe and effective method for hydrogen storage is integral to its use as an alternative source of energy. The goal of the studies described in this thesis was to investigate the feasibility of developing combustible hydrogen-generating compositions based on ammonia borane and novel energetic materials such as nanocomposite and mechanically alloyed reactive materials, recently obtained by Prof. Edward Dreizin's team at the New Jersey Institute of Technology (NJIT). Such compositions could be stored for long time and release hydrogen on demand, upon ignition. The first phase of the research included thermodynamic calculations for combustion of ammonia borane with various reactive materials obtained at NJIT. The second phase involved experiments with compositions that appeared to be promising based on thermodynamic calculations. An experimental setup with laser ignition of mixtures was developed for these experiments. As a result of these tests, further work was focused on mixtures of ammonia borane, gelled water, and mechanically alloyed Al/Mg powder. The last part of the research revealed the reaction mechanisms during combustion of these mixtures. For this purpose, isotopic tests, involving use of heavy water and mass-spectroscopy of gaseous combustion products, were conducted. The results of the present work indicate that combustible mixtures of ammonia borane, water, and mechanically alloyed Al/Mg powder are promising for the development of hydrogen generators that release large amounts of hydrogen upon ignition.

  14. Comparison of optimization techniques applied to nuclear fuel reload design; Comparacion de tecnicas de optimizacion aplicadas al diseno de la recarga de combustible nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J.J.; Castillo, A.; Montes, J.L.; Perusquia, R. [ININ, Carretera Mexico-Toluca s/n, 52750 La Marquesa, Ocoyoacac Estado de Mexico (Mexico)]. e-mail: jjortiz@nuclear.inin.mx

    2007-07-01

    In this work a comparison of three techniques of optimization is presented applied to the design of the recharge of fuel in reactors of water in boil. In short, the techniques were applied to the design of a recharge of a cycle of balance of 18 months of the Laguna Verde Nucleo electric Central. The used techniques were Genetic Algorithms, Taboo Search and Neural Nets. The conditions to apply the different techniques were the same ones. The comparison of the results quality and the computational resources required to obtain them, it indicates that with the Taboo Search better results are achieved but the computational cost is very big. On the other hand the neural net with low computational cost obtains acceptable results. Additionally to this comparison, in this work a summary of the works that have been carried out for the fuel recharges optimization from the years 60 until the present time is presented. (Author)

  15. Estrategias evolutivas para la adquisición de conocimiento en controladores borrosos temporales difuminados, aplicadas al encaminamiento adaptativo en redes de comunicaciones

    OpenAIRE

    Gadeo Martos, Manuel Ángel

    2009-01-01

    En esta tesis se presenta una metodología para mejorar las prestaciones de los algoritmos de encaminamiento adaptativos. El procedimiento propuesto está basado en el empleo sistemas borroso-genéticos evolutivos aplicados al encaminamiento adaptativo distribuido, en redes de comunicaciones de conmutación de paquetes. La metodología propuesta se puede descomponer en tres partes: 1.Desarrollo de los Controladores Borrosos Temporales Difuminados y Controladores Borrosos basados en Reglas Temporal...

  16. Preparation and photoluminescence of Tb3+ doped SrAl2O4 phosphor by composite combustion method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yanfang; LI Lan; ZHANG Xiaosong; WANG Dajian; ZHANG Sasa

    2008-01-01

    High-efficient Tb3+ activated SrAl2O4 phosphor was synthesized by a combined combustion-solid-state reaction method. The precursor of SrAl2O4:Th3+ phosphr was prepared via a combustion process, and then the as-prepared powder was heated in a reductive am-bient of activated carbon at 1250 ℃ for 1 h. The results of X-ray diffraction, scanning electron microscopy, and photoluminescence spectra revealed the influence of the dosage of urea and heated process on the crystallinity, morphology, and photoluminescence of the phosphor.Comparing with tradidonal solid-sate reaction, the crystallinity and emission intensity of the SrAl2O4:Th3+ phosphor were improved by this two-step process.

  17. Estrategias de crecimiento empresarial aplicadas por hipermercados

    OpenAIRE

    Miraidy Leal Morantes; Yilian Cefalá Chirinos

    2003-01-01

    El presente estudio tiene como objetivo caracterizar las estrategias de crecimiento empresarial, representadas por alianzas y adquisiciones, que han sido aplicadas en el sector de distribución de bienes de consumo masivo, específicamente en los hipermercados ubicados en Maracaibo, Estado Zulia, como manera de responder al entorno competitivo y cambiante en el cual se desenvuelven. La investigación se desarrolló a través de un estudio de carácter descriptivo; para la recolección ...

  18. Investigaciones dendrogeomorfológicas aplicadas al estudio de la peligrosidad por avenidas e inundaciones en el parque nacional de la Caldera de Taburiente (La Palma, Islas Canarias).

    OpenAIRE

    Díez Herrero, Andrés; Genova Fuster, Maria del Mar; Mayer Suárez, Pablo Lucas; Ballesteros Cánovas, Juan Antonio; Becerril Carretero, Laura; Rubiales Jimenez, Juan Manuel; Hernández Ruiz, M.; Saz Sánchez, M. A.; Bodoque del Pozo, Jose Maria; Ruiz Villanueva, V.

    2012-01-01

    La red de drenaje del parque nacional de la Caldera de Taburiente (La Palma, Islas Canarias) está constituida por numerosos torrentes tributarios del barranco de Las Angustias, que presentan frecuentes e intensos eventos de avenidas súbitas. Estas riadas han producido incluso víctimas mortales entre practicantes de senderismo (3 fallecidos en noviembre de 2001) e importantes pérdidas económicas al interferir con los proyectos de repoblación de las riberas con especies autóctonas (superio...

  19. Planificación tributaria aplicada al segmento económico del transporte aéreo internacional de pasajeros y carga

    OpenAIRE

    Lupera Carpio, Julio César

    2013-01-01

    El presente estudio tiene como propósito analizar los aspectos generales de la planificación tributaria en el Ecuador aplicado al segmento del transporte aéreo Internacional; el concepto, características, políticas, metas tributarias e importancia. Iniciaremos nuestro estudio analizando las características financieras y tributarias del transporte aéreo internacional y los tributos a los cuales se somete este segmento de la economía, detallando su forma peculiar de contribuir...

  20. Topología molecular aplicada al reconocimiento de sustratos de la Proteína de Resistencia del Cáncer de Mama (BCRP)

    OpenAIRE

    Gantner, Melisa Edith

    2016-01-01

    La disminución de la eficacia de un fármaco en el tratamiento o cura de una determinada enfermedad o condición se conoce como resistencia a los fármacos. La resistencia a múltiples fármacos o MDR (por sus siglas en inglés, multidrug resistance) se puede definir, en términos generales, como la capacidad de una célula viva u organismo de ofrecer resistencia al tratamiento frente a un amplio espectro de fármacos no relacionados estructural o funcionalmente entre sí. Una forma específica de MDR e...

  1. Combustion synthesis in the Ni-Al-Nb ternary system: A Time-Resolved X-ray Diffraction study

    Science.gov (United States)

    Sytschev, Alexander E.; Kovalev, Dmitry Yu.; Vrel, Dominique; Vadchenko, Sergey G.

    Combustion synthesis of intermetallics, using the thermal explosion mode, in the Ni-Al-Nb ternary system is presented, with a 40:40:20 atomic ratio. The kinetic pathway is determined using Time-Resolved X-ray Diffraction, with a time-step resolution of 1 s and demonstrated a first formation of the B2 NiAl structure followed by progressive dissolution of Nb to yield NiAlNb intermetallic Laves phase, representing 35 w% of the final product. SEM observations show a double dendritic (coarse and fine) microstructure, resulting from eutectic crystallization. Due to a high cooling rate, Nb dissolution is not complete at the surface, and yields slightly more complex microstructure, including the Ni2AlNb Geissler phase, the (Ni,Al)2Nb Laves phase, and (Ni, Al)7Nb6.

  2. Didáctica del dibujo de contornos ciegos aplicada al retrato gráfico = Teaching the blind contours drawing applied to graphic portrait

    Directory of Open Access Journals (Sweden)

    Ignacio Martínez de Salazar Muñoz

    2016-07-01

    Full Text Available Resumen En el área de la enseñanza del Dibujo Artístico, el retrato es una de las temáticas más complejas e interesantes a las que un estudiante debe enfrentarse. Con una larga tradición en las artes plásticas este género gráfico ofrece un campo de estudio excepcional para la adquisición de competencias básicas relacionada con la praxis del dibujo. El presente artículo muestra los resultados de una propuesta didáctica realizada con estudiantes en el contexto de los estudios universitarios de Diseño. Los objetivos que este estudio persigue son proporcionar una estrategia didáctica complementaria a los métodos de enseñanza del Dibujo Artístico, ofreciendo al docente y al estudiante herramientas que favorezcan la comprensión, validación y ejecución del retrato gráfico. Abstract In the Artistic Drawing education, the portrait is one of the most complex and interesting topics to which students must face. With a long tradition within the plastic arts, this graphic genre offers an unique field of study to acquire basic skills related to the practice of drawing. This artículo reports the results of an innovative didactic project performed with university students of the Design studies. The aim of the project is to provide a complementary teaching strategy to the traditional methods of the Artistic Drawing training. It offers to both, the teacher and the students, distinct tools to promote the understanding, validation and implementation of the graphic portrait.

  3. Synthesis of Nano Crystalline MgAl2O4Spinel Powder by Microwave Assisted Combustion%Synthesis of Nano Crystalline MgAl2O4 Spinel Powder by Microwave Assisted Combustion

    Institute of Scientific and Technical Information of China (English)

    Leila Torkian; Mostafa M Amini; Zohreh Bahrami

    2011-01-01

    Stoichiometric MgAl2O4 spinel nanoparticles were synthesized by microwave assisted combustion reaction from aluminium nitrate nanohydrate (Al(NO3)3.9H2O) and Sol-Gel prepared magnesium hydroxide (Mg(OH)2) in the presence of urea ((NH2)2CO) as a fuel, in about 20 min of irradiation. X-ray diffraction (XRD) studies reveal that microwave assisted combustion synthesis route yields single-phase spinel nanoparticles with larger crystalline size (around 75 nm) than other conventional heating methods. Scanning electronic microscope (SEM) images show nanoparticles with spherical shape and homogenous morphology. The surface area measurements (SBET) show crystals with 2.11 m2/g and 0.0033 mL/g pore volume.

  4. Image quality analysis vs dose to the patient in digital panoramic radiography; Analisis de calidad de imagen vs dosis aplicada al paciente en radiografia panoramica digital

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Diaz, M.; Borges-Garcia, T.; Leon-Santana, J.; Vanderley-Brasileiro, I.; Khoury, H.; Miranda-Cataneda, M.

    2012-11-01

    Digital panoramic radiography is a diagnostic image technique which is increasing its use today allo over the world. Nevertheless, there is a relative lack of knowledge about the best compromise relationship between image quality and dose to the patient for these studies. Twenty one panoramic images of an anthropomorphic phantom and 205 from patients were collected using a Kodak digital equipment. Tube current, beam energy and acquisitions time were changed among studies to look for the best acquisition conditions which permit good image quality al low doses for patients. Air Kerma-Length Product was measures as dose index. Image quality was graded using objective metrics as Signal to Noise Ratio (SNR [dB]) and Contrast to Noise ratio (CNR), as well as visual evaluation with two expert observers. Reduction in dose was able, reducing mAs mainly, without affecting image quality in a sensitive way. An optimized protocol for this equipment was also obtained for standard height and weight patients. (Author)

  5. Evaluation of the reaction rate constants for the gas-phase Al-CH4-air combustion chemistry

    Science.gov (United States)

    Sharipov, A. S.; Titova, N. S.; Starik, A. M.

    2012-10-01

    The most likely reaction pathways and reaction products in the Al-CH4-O2-N2 system are investigated using density functional theory and ab initio calculations. The B3LYP functional with extended 6-311+G(3df,2p) basis set as well as the CBS-QB3 composite method are mainly utilised. Theoretical analysis of corresponding reaction rate constants is also performed with the use of simple theoretical models. A critical overview of current knowledge on combustion-relevant reactions with aluminium compounds is given. On the basis of critical comparison of available experimental kinetic data with theoretical calculations, the approximations for rate constants for 44 reversible elementary reactions involving Al-containing species are recommended for use in combustion issues.

  6. Influences of Mechanical Vibration on Rapidly Solidified Al2O3/YSZ Ceramics Prepared by Combustion Synthesis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhong-min; ZHANG Long; WANG Wei-guo; ZHANG Shi-yue

    2006-01-01

    Al2O3/YSZ composite ceramics was fabricated with combustion synthesis technology, and the influences of mechanical vibration on its microstructures and properties were investigated. It is found that under the mechanical vibration of ever-increasing frequency, increasing combustion temperature, accelerating ceramics/metal liquid-liquid separation and quickening ceramic solidification could not only reduce the average diameter and the size distribution of aligned ZrO2 nano-micron fibers in rod-shaped Al2O3 matrix grains, but also make the randomly-oriented rod-shaped grains finer and increase their aspect ratios. As a result, a remarkable increase in flexural strength and fracture toughness of the ceramics can be observed.

  7. LA DENSIDAD ÓPTICA APLICADA AL ESTUDIO LECTINHISTOQUÍMICO DE RADICALES GLUCÍDICOS NÉFRICOS EN RATAS DIABÉTICAS TIPO 2

    Directory of Open Access Journals (Sweden)

    Ana V Frontini

    2008-01-01

    Full Text Available Este trabajo analiza, mediante densidad óptica (DO, residuos glucídicos en glomérulos y túbulos contorneados proximales, superficiales y yuxtamedulares, de dos líneas de ratas diabéticas: eSS y eSMT al año de edad. 10 ratas macho eSS, 12, eSMT y 10, Wistar (controles fueron estudiadas con distintas lectinas (PNA, RCA, Con-A, DBA, SBA, WGA y UEA-I. La densidad óptica (DO fue determinada mediante el Programa Image-pro Plus versión 1.1, estableciéndose rangos para la evaluación de la reacción cromogénica (> 200 = 0 (negativa; entre 150 y 200 = 1-2 (débil o moderada positividad, y < 150 = 3 (fuerte positividad. Los principales resultados diferenciales fueron registrados: (a en los glomérulos superficiales: WGA: eSMT (DO=3 versus eSS y Wistar (DO = 1-2, y UEA-I y Con-A: Wistar (DO= 3 versus líneas diabéticas (DO =1-2; (b en los glomérulos yuxtamedulares: WGA: Wistar y eSMT (DO = 3 versus eSS (DO= 1-2, UEA-I: líneas diabéticas (DO= 3 versus Wistar (DO=1-2, y Con-A: Wistar (DO =3 versus líneas diabéticas (DO = 1-2, y (c en las células de los túbulos proximales yuxtamedulares: WGA y Con-A: líneas diabéticas (DO=1-2 versus Wistar (DO= 3, y UEA-I: eSS (DO=3 versus eSMT y Wistar (DO=1-2. Las diferencias entre ratas diabéticas y controles podrían atribuirse a su dismetabolismo, y las de las líneas diabéticas entre sí, a sus distintos orígenes. Asimismo, podrían señalar alteraciones en la filtración y en procesos tubulares intracelulares, coincidiendo con trabajos previos acerca de una nefropatía en evolución a esta edad en eSS y eSMT.

  8. Loss Distribution Approach (LDA: metodología actuarial aplicada al riesgo operacional Loss Distribution Approach (LDA: actuarial methodology apply to operational risk

    Directory of Open Access Journals (Sweden)

    Luis Ceferino Franco Arbeláez

    2008-07-01

    Full Text Available Este artículo es resultado de un proyecto de investigación sobre la gestión integral del riesgo operacional promovido por la Vicerrectoria de Investigaciones de la Universidad de Medellín, y cofinanciado por una firma comisionista. Se presenta una aplicación del modelo LDA, el cual se basa en la recopilación de los datos de pérdidas históricas (frecuencia y severidad, que se registran internamente en las organizaciones. Dichos datos pueden ser complementados con datos externos. Estas pérdidas son clasificadas en una matriz que relaciona las líneas de negocio de la organización y los eventos operacionales de pérdida, a partir de la cual se calcula la carga de capital. La aplicación se desarrolló para una entidad financiera. El artículo está organizado de la siguiente forma: la primera sección es introductoria al tema. En la segunda parte se presenta formalmente el modelo LDA; luego se realiza una aplicación, y en la cuarta sección se presentan algunas conclusiones.This paper is the result of a research project on integrated management of operational risk, promoted by Universidad de Medellin Research Vice-Principal's Office and co-financed by a financial company. It presents an application of the LDA model, which is based on data collection of historical losses (frequency and severity, which are recorded internally in organizations. Such data can be supplemented with external data. These losses are classified in a matrix that relates business lines of the organization and operational loss events, from which capital charge is estimated. The application was developed for a financial institution. The paper is organized as follows: The first section is introductory to the subject. The second part formally presents a LDA model; then an application is made, and in the fourth part some conclusions are presented.

  9. Precisión diagnóstica de la angiografía coronaria por tomografía computarizada multislice aplicada al “mundo real”

    Directory of Open Access Journals (Sweden)

    Claudio Llauradó

    2006-01-01

    Full Text Available Objetivo Evaluar la precisión diagnóstica de la angiografía coronaria por tomografía computarizada multislice (ACTCM para la detección de estenosis significativas en arterias coronarias. Material y métodos Se estudiaron pacientes con indicación de cinecoronariografía diagnóstica sin antecedents de alergia al contraste, insuficiencia renal ni arritmias. Para la adquisición de imágenes se utilizó un tomógrafo multislice (multicorte ( Brilliance 40, Philips, The Netherlands gatillado electrocardiográficamente. Se administraron 90-125 ml de contraste yodado por vía endovenosa. La obesidad, la diabetes, los segmentos difusamente calcificados, con diámetro < 2,0 mm, y aquellos tratados con stents no constituyeron criterios de exclusión. Las lesiones se definieron significativas cuando presentaron una reducción luminal = 50% por ACTCM y angiografía cuantitativa coronaria (QCA. Resultados Previo a la intervención se escanearon 38 pacientes. De ellos, uno (3% fue excluido debido a calidad de imagen insuficiente. Los 37 restantes (444 segmentos, con calidad de scan satisfactoria, se incluyeron en el estudio (81% hombres, edad media 62,43 ± 12,5 años, 13,5% diabéticos. El tiempo medio de scan fue de 15,12 ± 2,6 segundos. Se analizaron 444 segmentos por ambas técnicas. Se encontraron 88 (17% y 93 (18% lesiones significativas por CCG y ACTCM, respectivamente. La sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo de la ACTCM para detectar estenosis significativas fueron del 82%, 93%, 72% y 96%, respectivamente. Conclusión En pacientes seleccionados para cinecoronariografía, la angiografía coronaria por tomografía computarizada multislice presenta un alto valor predictivo negativo para la detección de enfermedad obstructiva coronaria.

  10. EFECTO DE DOS OLIGOSACARINAS SOBRE LA EXPRESIÓN ISOENZIMÁTICA AL SER APLICADAS SOBRE DOS VARIEDADES DE TABACO (Nicotiana tabacum L.

    Directory of Open Access Journals (Sweden)

    A. Acosta

    2007-01-01

    Full Text Available En Cuba se trabaja en la búsqueda y producción de nuevas fitohormonas, entre las que se encuentran el Pectimorf y los xiloglucanos. El principio activo de estas es una mezcla de oligosacáridos, en el primer caso de origen péctico (Patente No. 1198/171 y en el segundo, de hemicelulosa. Se plantea que ambos son reguladores endógenos del desarrollo y la morfogénesis de las plantas y, además, inducen respuestas de defensa. Sin embargo, menos conocidos son los mecanismos moleculares que se activan, por lo que se continúan los estudios para evaluar el papel que juegan y las vías por las que actúan dichos compuestos en el desarrollo de las plantas. Para obtener una primera aproximación del mecanismo de acción de ambos compuestos sobre el genoma, se analizó la expresión de cuatro sistemas isoenzimáticos -Peroxidasas, Polifenoloxidasas, Anhidrasas Carbónicas y Esterasas- en dos variedades de tabaco (Nicotiana tabacum L., tratadas con los bioproductos. Los resultados se analizaron estadísticamente mediante el paquete de programas NTSYS-PC y se valoró su importancia sobre el desarrollo y la morfogénesis de las plantas. Como resultado se obtuvieron los zimotipos característicos para cada sistema isoenzimático de las dos variedades estudiadas (H-2000 y H-2.1.1. Además, se observó inhibición y/o inducción de isoformas en las plantas crecidas en medio suplementado con ambos biorreguladores, en comparación a los controles empleados. Estos resultados evidenciaron una modulación de la expresión de la información genética mediada por estos productos, al menos, para los cuatro sistemas analizados en el cultivo empleado.

  11. Culturability of Bacillus spores on aerosol collection filters exposed to airborne combustion products of Al, Mg, and B·Ti.

    Science.gov (United States)

    Adhikari, Atin; Yermakov, Michael; Indugula, Reshmi; Reponen, Tiina; Driks, Adam; Grinshpun, Sergey A

    2016-05-01

    Destruction of bioweapon facilities due to explosion or fire could aerosolize highly pathogenic microorganisms. The post-event air quality assessment is conducted through air sampling. A bioaerosol sample (often collected on a filter for further culture-based analysis) also contains combustion products, which may influence the microbial culturability and, thus, impact the outcome. We have examined the interaction between spores deposited on collection filters using two simulants of Bacillus anthracis [B. thuringiensis (Bt) and B. atrophaeus (referred to as BG)] and incoming combustion products of Al as well as Mg and B·Ti (common ingredient of metalized explosives). Spores extracted from Teflon, polycarbonate, mixed cellulose ester (MCE), and gelatin filters (most common filter media for bioaerosol sampling), which were exposed to combustion products during a short-term sampling, were analyzed by cultivation. Surprisingly, we observed that aluminum combustion products enhanced the culturability of Bt (but not BG) spores on Teflon filters increasing the culturable count by more than an order of magnitude. Testing polycarbonate and MCE filter materials also revealed a moderate increase of culturability although gelatin did not. No effect was observed with either of the two species interacting on either filter media with products originated by combustion of Mg and B·Ti. Sample contamination, spore agglomeration, effect of a filter material on the spore survival, changes in the spore wall ultrastructure and germination, as well as other factors were explored to interpret the findings. The study raises a question about the reliability of certain filter materials for collecting airborne bio-threat agents in combustion environments.

  12. Pocket wheel engine as an internal combustion engine. Taschenscheibenmotor als Verbrennungsmotor

    Energy Technology Data Exchange (ETDEWEB)

    Hellmuth, H.J.

    1990-09-27

    All spark ignition and diesel engines have large oscillating masses, a high frictional resistance and do not run vibration-free. Wankel engines effect only a partial combustion due to the unfavourable shape of the combustion chamber: the expansive force is converted into rotating movement via mechanical deflection. The new internal combustion engine is to have a low weight, require little space and run vibration-free with a high efficiency. The expansive force is to be converted directly into rotating movement. A screw compressor (3) suctions and compresses an air-fuel mixture. The combustion chamber is charged periodically with the compressed mixture via a slit side shaft (6). The slit side shaft (6) closes the combustion chamber (7) at the rear. The mixture is ignited. The flap (8) opens the combustion chamber (7) at the front and the exanding gas sets the pocket wheel connected to the main shaft (15) rotating. The compressor (3) and the slit side shaft (6) are driven directly by the main shaft (15). The pocket wheel engine can be employed in all fields where internal combustion engines have been used until now.

  13. La Kinesiologia aplicada als músics

    OpenAIRE

    Velàzquez, Mònica

    2010-01-01

    La kinesiologia és una de les tècniques més globals per tractar els desequilibris energètics, musculars i les pors escèniques. En tractar-se d’una teràpia holística, es contempla el pacient com un tot.

  14. Tendencias en investigación sobre seguridad y salud laboral: Propuesta metodológica aplicada al sector de la construcción Trends in research about occupational safety and health: Methodology applied to the construction industry

    Directory of Open Access Journals (Sweden)

    Gloria Isabel Carvajal Peláez

    2009-07-01

    Full Text Available En este artículo se realiza un análisis de las tendencias en investigación sobre seguridad y salud ocupacional aplicadas al sector de la construcción. Se investigaron fuentes publicadas en inglés (1930 -2007 y se encontraron más de 250 artículos. Para clasificar la información, se propone el "ciclo riesgo accidente" formado por cinco pasos que reflejan la realidad de la seguridad laboral en la construcción. Para cada paso, se seleccionaron las publicaciones más representativas y se elaboraron árboles de evolución lógica teniendo en cuenta el contenido, grado de importancia, orden cronológico, aplicación sobre cada tema, etc. Con estos árboles, se pasa de lo general a lo particular en forma cronológica, para demostrar las tendencias actuales en investigación en seguridad y salud en la construcción y podemos concluir que la investigación en este aspecto sigue siendo escasa, tratándose de un campo lleno de oportunidades y con un futuro prometedor.This article analyzes trends in research in occupational safety and health applied to the construction industry. The sources of information published in English (1930-2007 and found more than 250 articles. In order to classify these documents, is proposed the "risk-accident cycle" composes by five steps that reflect the reality of occupational safety and health in the construction industry. For each one of them, the papers more representative were selected and later elaborated a tree of chronological evolution considering aspects such as the content, degree of importance, chronological order, application on each subject, etc. With the elaboration of these trees, show the passage of the general to the particular in chronological form, for demonstrating the actual trends in research in safety and health in the construction. As a final remark, nowadays, research in safety and health in the construction is still very limited, being a field with many opportunities and a promising future.

  15. Effect of milling time on TiB2-Al2O3 composite produced by combustion synthesis

    Science.gov (United States)

    Aminikia, Behzad

    2012-09-01

    In this present research, TiB2-Al2O3 composite was fabricated by self-propagating hightemperature synthesis (SHS) of mechanically activated powders. H3BO3, TiO2 and Al as starting materials were mechanically activated for 1, 3, 6 and 9 h then pressed to form pellets. Green compacts were placed in a tube furnace with argon atmosphere, for synthesis. According to the XRD patterns showed that the TiB2-Al2O3 composite has been successfully fabricated by thermal explosion mode of combustion synthesis. Also, it was found that, 6 h is the optimum time for mechanical activation. That increasing milling time up to 9 h had no significant effect other than refining the crystallite sizes of the components specially TiB2.

  16. Deposition of LaMO3 (M=Ni,Co,Cr,Al)-Oriented Films by Spray Combustion Flame Technique

    Science.gov (United States)

    Ichinose, Hiromichi; Shiwa, Yuzo; Nagano, Masamitsu

    1994-10-01

    LaMO3 (M=Ni,Co,Cr,Al) films were prepared on sintered alumina, sapphire (001) and MgO(100) at 500 900°C by spraying ultrasonically atomized aqueous solutions of nitrates into a combustion flame (spray combustion flame technique). LaNiO3 and LaCoO3 on MgO(100) crystallized in high-temperature phases (cubic) while LaCrO3 and LaAlO3 crystallized in room-temperature phases. LaMO3 (M=Ni,Co,Cr,Al) films on MgO(100) were highly oriented to (100), (100), (001) and (100), respectively, while the films on sintered alumina and sapphire were not. The electric resistivities of the dense LaMO3 (M=Ni,Co,Cr) films were as low as those of bulk ceramics. LaNiO3 film deposited on MgO above 700°C showed the lowest resistivity of about 6×10-6 Ω m. It was suggested that the reactivities of the constituent metal atoms with OH in the flame are associated with the preferred phase and the morphology of the films.

  17. Application of Fe2O3/Al2O3 Composite Particles as Oxygen Carrier of Chemical Looping Combustion

    Institute of Scientific and Technical Information of China (English)

    Fang He; Hua Wang; Yongnian Dai

    2007-01-01

    Chemical looping combustion (CLC) of carbonaceous compounds has been proposed, in the past decade, as an efficient method for CO2 capture without cost of extra energy penalties. The technique involves the use of a metal oxide as an oxygen carrier that transfers oxygen from combustion air to fuels.The combustion is carried out in a two-step process: in the fuel reactor, the fuel is oxidized by a metal oxide, and in the air reactor, the reduced metal is oxidized back to the original phase. The use of iron oxide as an oxygen carrier has been investigated in this article. Particles composed of 80 wt% Fe2O3,together with Al2O3 as binder, have been prepared by impregnation methods. X-ray diffraction (XRD) analysis reveals that Fe2O3 does not interact with the Al2O3 binder after multi-cycles. The reactivity of the oxygen carrier particles has been studied in twenty-cycle reduction-oxidation tests in a thermal gravimetrical analysis (TGA) reactor. The components in the outlet gas have been analyzed. It has been observed that about 85% of CH4 converted to CO2 and H2O during most of the reduction periods. The oxygen carrier has kept quite a high reactivity in the twenty-cycle reactions. In the first twenty reaction cycles, the reaction rates became slightly higher with the number of cyclic reactions increasing, which was confirmed by the scanning electron microscopy (SEM) test results. The SEM analysis revealed that the pore size inside the particle had been enlarged by the thermal stress during the reaction, which was favorable for diffusion of the gaseous reactants into the particles. The experimental results suggested that the Fe2O3/Al2O3 oxygen carrier was a promising candidate for a CLC system.

  18. Synthesis, characterizations, antibacterial and photoluminescence studies of solution combustion-derived α-Al2O3 nanoparticles

    Directory of Open Access Journals (Sweden)

    P.A. Prashanth

    2015-09-01

    Full Text Available In this work, we report a novel, economical, low temperature solution combustion synthesis (SCS method to prepare α-Al2O3 (Corundum nanoparticles. Powder X-ray diffraction (PXRD, field emission scanning electron microscopy (FE-SEM, high-resolution transmission electron microscopy (HR-TEM, Fourier transform infrared spectroscopy (FT-IR, BET surface area and ultraviolet visible spectroscopy (UV–vis measurements were used to characterize the product. Antibacterial studies were examined against gram −ve Klebsiella aerogenes, Escherichia coli, Pseudomonas desmolyticum and gram +ve Staphylococcus aureus bacteria by agar well diffusion method. The α-Al2O3 nanoparticles showed substantial effect on all the four bacterial strains. Photoluminescence (PL measurements under excitation at about 255 nm show that the alumina nanoparticles have emission peaks at 394 and 392 nm.

  19. TL/OSL properties of beta irradiated Al2O3 Nanophosphor synthesized by microwave combustion method

    Science.gov (United States)

    Reddy, S. Satyanarayana; Nagabhushana, K. R.; Chauhan, Naveen; Singh, Fouran

    2017-05-01

    Stable α-phase of Al2O3 is synthesized by combustion method usingtemperature controlled microwave oven. Crystalline phase is analyzed by X-ray diffraction (XRD)and average crystallite size is found to be 75 nm. Thermoluminescence (TL) glow curve of Al2O3 is studied in UV, blue and open (visible) windows after beta irradiation. A prominent TL glow with peak at 472 K along with shoulders at 416 and 513 K are observed in all three windows. These peaks may be ascribed to F, F2 and F+- centers. Highest TL intensity isobserved inopen window. Optically stimulated luminescence (OSL) studies in UV and blue windows shows highest intensityin UV window. TL/OSL of phosphor shows linearresponse with beta dose upto 6.16 Gy.TL/OSL properties viz fading,repeatabilityand MDDare studied. TL kinetic parameters are estimated by deconvolution with computerized glow curve deconvolution (CGCD) techniques.

  20. Voigt modelling of size–strain analysis: Application to -Al2O3 prepared by combustion technique

    Indian Academy of Sciences (India)

    K Santra; P Chatterjee; S P Sen Gupta

    2002-06-01

    A comprehensive analysis of size and strain broadened profile shapes in X-ray diffraction line broadening analysis is presented. Both size and strain broadened profiles were assumed to be Voigtian and the derived microstructural parameters (size and strain) were found to be in close agreement with those calculated from model independent Warren–Averbach method. The method is applied to three different alumina samples viz. micron size -alumina (-Al2O3) prepared by the combustion of aluminium nitrate and urea mixture, annealed samples and commercial -Al2O3 sample. It is likely from the present analysis that a significant Gaussian size contribution is related to narrow size distribution observed from the analysis. It has been concluded that present Voigtian analysis is more reliable and may largely replace the earlier simplified integral breadth methods of analysis often used in line broadening analysis.

  1. A study of Cu/ZnO/Al2O3 methanol catalysts prepared by flame combustion synthesis

    DEFF Research Database (Denmark)

    Jensen, Joakim Reimer; Johannessen, Tue; Wedel, Stig;

    2003-01-01

    The flame combustion synthesis of Cu/ZnO/Al2O3 catalysts for the synthesis of methanol from CO, CO2 and H2 is investigated. The oxides are generated in a premixed flame from the acetyl-acetonate vapours of Cu, Zn and Al mixed with the fuel and air prior to combustion. The flame-generated powder...... is examined by X-ray powder diffraction, determination of the specific surface area by the BET-method, determination of the copper dispersion in the reduced catalyst by a novel N2O-method, by transmission electron microscopy, and by test of the catalytic properties in a catalytic micro-reactor. A low peak...... temperature and quench-cooling of the flame tend to increase the dispersion of the phases and the specific surface area of the particles. Properties of both the ternary composition, the three binary compositions and the pure oxides are discussed. The calculation of simultaneous phase and chemical equilibrium...

  2. Ignition and Combustion Characteristics of Nanoscale Al/AgIO3: A Potential Energetic Biocidal System

    Science.gov (United States)

    2011-01-01

    use in thermite-based biocidal applications (Johnson et al., 2008). Silver exhibits biocidal properties in many forms (Rentz, 2003). Morones et al...polymer composites have been reported to exhibit potent, long lasting antibacterial activity (Sambhy et al., 2006), and silver iodide is used as an...see in Table 1 that the Al=AgIO3 ther- mite has a higher adiabatic flame temperature and also has the potential to produce more gas than the two metal

  3. Macroeconomía aplicada

    OpenAIRE

    Tenorio Aguilar, Raymindo

    2012-01-01

    Macroeconomía aplicada es un eBook de texto para estudiantes de nivel profesional, particularmente del área de negocios, que facilita el aprendizaje  del funcionamiento de la economía y su influencia en la vida cotidiana de empresas, gobierno y sociedad. Sus contenidos teórico-prácticos son vigentes y actuales; altamente vinculados a la comprensión de la economía en su conjunto y en particular a la economía mexicana.

  4. Efectos clínicos y antiinflamatorios de la radiación láser de Nd:YAG aplicada adiionalmente al tratamiento no-quirúrgico en periodontitis crónica

    OpenAIRE

    Egido Manchado, Mª Cristina

    2012-01-01

    El objetivo principal del presente trabajo de investigación fue comparar la respuesta entre el tratamiento periodontal convencional y el mismo tratamiento complementado con Terapia Láser, mediante el empleo de la radiación procedente de un láse de Nd:YAG, bien aplicada en una única dosis o bien en dosis repetidas desde un punto de vista clínico, inflamatorio y antioxidante, en pacientes adultos afectados de periodontitis crónica.En términos generales se observó a nivel clínico una mejora de l...

  5. Combustion Synthesized Cr3+-doped-BaMgAl10O17 Phosphor: An Electron Paramagnetic Resonance and Optical Study

    Science.gov (United States)

    Singh, Vijay; Sivaramaiah, G.; Rao, J. L.; Srivastava, Anoop K.; Ravikumar, R. V. S. S. N.; Dhoble, S. J.; Singh, P. K.; Mohapatra, Manoj

    2016-01-01

    BaMgAl10O17 phosphors doped with Cr3+ ions were prepared by a combustion route at a furnace temperature of 773 K. The X-ray diffraction pattern revealed that the BaMgAl10O17 phosphor was in a hexagonal phase. Energy-dispersive X-ray mapping images demonstrated the presence of the dopant ion in the BaMgAl10O17 matrix. The bands observed in the optical absorption spectrum were characteristic of Cr3+ ions in octahedral geometry. Upon 555-nm excitation, an intense narrow red emission line centred at 690 nm due to the 2Eg → 4A2g transition of Cr3+ ions was observed. The electron paramagnetic resonance (EPR) spectrum of Cr3+ ions in BaMgAl10O17 phosphor showed multiple absorption bands having at least 6 g values. Based on the EPR data, various parameters such as the absolute number of spins, Gibbs potential, magnetic susceptibility and magnetic moments, Curie constant, etc., for the system were evaluated.

  6. Combustion synthesis of blue-emitting submicron CaAl4O7:Eu2+, Dy3+ persistence phosphor.

    Science.gov (United States)

    Yerpude, A N; Dhoble, S J

    2012-01-01

    Long persistence phosphor CaAl4O7:Eu(2+), Dy(3+) were prepared by a combustion method. The phosphors were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), decay time measurement techniques and photoluminescence spectra (PL). The CaAl4O7:Eu(2+), Dy(3+) phosphor showed a broad blue emission, peaking at 445 nm when excited at 341 nm. Such a blue emission can be attributed to the intrinsic 4f → 5d transitions of Eu(2+) in the host lattices. The lifetime decay curve of the Dy(3+) co-doped CaAl4O7:Eu(2+) phosphor contains a fast decay component and another slow decay one. Surface morphology also has been studied by SEM. The calculated CIE colour chromaticity coordinates was (0.227, 043). We have also discussed a possible long-persistent mechanism of CaAl4O7:Eu(2+), Dy(3+) phosphor. All the results indicate that this phosphor has promising potential for practical applications in the field of long-lasting phosphors for the purposes of sign boards and defence. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Influence of MnC2O4 microadditives on combustion characteristics of CuO/Al nanoenergetics

    Science.gov (United States)

    Painuly, Madhusudan; Patel, Vinay Kumar; Bhattacharya, Shantanu

    2016-05-01

    In this work, we have investigated the catalytic effect of MnC2O4 microrods on combustion characteristics of CuO/nAl nanoenergetic composites. CuO nanorods were prepared by solid state synthesis method using the nonionic surfactant of poly(ethylene)glycol of molecular weight 400 (PEG400). The crystal information and microstructure of CuO/nAl nanoenergetics were studied by X-ray diffractometry and Transmission Electron microscopy. Microrods shaped manganese oxalate (MnC2O4) were fabricated by using mild thermal precipitation and aging process and confirmed by energy dispersive X-ray spectroscopy (EDS). The microstructures of MnC2O4 microrods and the nanoenergetic composites of CuO/nAl/MnC2O4 were characterized by Field emission scanning electron microscopy (FE-SEM) imaging. The addition of MnC2O4 microrods has demonstrated a significant enhancement in dynamic pressure-time characteristics of CuO/nAl nanoenergetics.

  8. Study of CeO₂ Modified AlNi Mixed Pillared Clays Supported Palladium Catalysts for Benzene Adsorption/Desorption-Catalytic Combustion.

    Science.gov (United States)

    Li, Jingrong; Zuo, Shufeng; Yang, Peng; Qi, Chenze

    2017-08-15

    A new functional AlNi-pillared clays (AlNi-PILC) with a large surface area and pore volume was synthesized. The performance of adsorption/desorption-catalytic combustion over CeO2-modified Pd/AlNi-PILC catalysts was also studied. The results showed that the d001-value and specific surface area (SBET) of AlNi-PILC reached 2.11 nm and 374.8 m²/g, respectively. The large SBET and the d001-value improved the high capacity for benzene adsorption. Also, the strong interaction between PdCe mixed oxides and AlNi-PILC led to the high dispersion of PdO and CeO₂ on the support, which was responsible for the high catalytic performance. Especially, 0.2% Pd/12.5% Ce/AlNi-PILC presented high performance for benzene combustion at 240 °C and high CO₂ selectivity. Also, the combustion temperatures were lower compared to the desorption temperatures, which demonstrated that it could accomplish benzene combustion during the desorption process. Furthermore, its activity did not decrease after continuous reaction for 1000 h in dry air, and it also displayed good resistance to water and the chlorinated compound, making it a promising catalytic material for the elimination of volatile organic compounds.

  9. Use of Al{sub 4}C{sub 3} for fabrication of alumina–niobium carbide composites by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, C.L., E-mail: clyeh@fcu.edu.tw; Chen, Y.S.

    2014-03-15

    Highlights: • SHS with aluminothermic reduction was performed for formation of NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites. • Al{sub 4}C{sub 3} prevents carbothermic reduction of Nb{sub 2}O{sub 5}, leading to improved product formation. • Optimum sample compositions were obtained for formation of NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites. • Variations of combustion temperature and velocity with sample stoichiometry were presented. -- Abstract: Alumina–niobium carbide (Al{sub 2}O{sub 3}–NbC and Al{sub 2}O{sub 3}–Nb{sub 2}C) composites were synthesized by incorporating aluminothermic reduction of Nb{sub 2}O{sub 5} into a self-propagating combustion process. Starting materials of this study included Nb{sub 2}O{sub 5}, Al, Al{sub 4}C{sub 3} and carbon powders. Experimental evidence indicated that combustion temperature and flame-front velocity decreased with increasing elemental carbon in the reactant mixture. The use of Al{sub 4}C{sub 3} as the source of carbon was demonstrated to prevent carbothermic reduction of Nb{sub 2}O{sub 5}. As a result, the combustion exothermicity was increased and phase transformation and product densification were improved. According to the composition analysis, the carbon-free samples composed of Nb{sub 2}O{sub 5}:Al:Al{sub 4}C{sub 3} = 3:2:2 and 3:6:1 successfully produced NbC and Nb{sub 2}C–Al{sub 2}O{sub 3} composites, respectively, with very few minor phases.

  10. The Effects of Gravity on the Combustion Synthesis of B2O3-Al2O3-MgO Glass Ceramic Composites

    Science.gov (United States)

    Manerbino, A. R.; Yi, H. C.; Guigne, J. Y.; Moore, J. J.; Schowengerdt, F. D.

    2000-01-01

    Glass ceramic composites based on B2O3-Al2O3-MgO have been produced by combustion synthesis in a Self-propagating mode. The gravitational effects on the combustion characteristics such as combustion wave velocity (V), and combustion temperature (T(sub c)) were studied. The results showed that the gravitational effects on these parameters were inconclusive. The microstructure of this system has also been analyzed with X-ray Diffraction and light microscopy. These results showed a higher amount of divitrification occurs under both reduced gravity and high gravity conditions. The gravitational effects on formation of pores, overall porosity and apparent porosity for this family of glass-ceramics also shows to be inconclusive. Possible reasons for these results are discussed.

  11. Estadística aplicada a Psicología

    OpenAIRE

    Chorro Gascó, Juan Luis

    2012-01-01

    Este documento es un curso de introducción a Estadística aplicada al análisis de datos en Psicología. Está estructurado en dos bloques de temas de Estadística Descriptiva e Inferencial, que incluyen contenidos teóricos y ejercicios. La página de inicio da acceso a cada bloque, y una vez dentro se accede a los contenidos a través de un menú desplegable. Curs d’introducció a Estadística aplicada a l’anàlisi de dades en Psicologia. Els temes estan agrupats en dos blocs, un per Estadística Des...

  12. Estadística aplicada a Psicología

    OpenAIRE

    2012-01-01

    Este documento es un curso de introducción a Estadística aplicada al análisis de datos en Psicología. Está estructurado en dos bloques de temas de Estadística Descriptiva e Inferencial, que incluyen contenidos teóricos y ejercicios. La página de inicio da acceso a cada bloque, y una vez dentro se accede a los contenidos a través de un menú desplegable. Curs d’introducció a Estadística aplicada a l’anàlisi de dades en Psicologia. Els temes estan agrupats en dos blocs, un per Estadística Des...

  13. Development of a CuNiCrAl Bond Coat for Thermal Barrier Coatings in Rocket Combustion Chambers

    Science.gov (United States)

    Fiedler, Torben; Rösler, Joachim; Bäker, Martin

    2015-12-01

    The lifetime of rocket combustion chambers can be increased by applying thermal barrier coatings. The standard coating systems usually used in gas turbines or aero engines will fail at the bond coat/substrate interface due to the chemical difference as well as the different thermal expansion between the copper liner and the applied NiCrAlY bond coat. A new bond coat alloy for rocket engine applications was designed previously with a chemical composition and coefficient of thermal expansion more similar to the copper substrate. Since a comparable material has not been applied by thermal spraying before, coating tests have to be carried out. In this work, the new Ni-30%Cu-6%Al-5%Cr bond coat alloy is applied via high velocity oxygen fuel spraying. In a first step, the influence of different coating parameters on, e.g., porosity, amount of unmolten particles, and coating roughness is investigated and a suitable parameter set for further studies is chosen. In a second step, copper substrates are coated with the chosen parameters to test the feasibility of the process. The high-temperature behavior and adhesion is tested with laser cycling experiments. The new coatings showed good adhesion even at temperatures beyond the maximum test temperatures of the NiCrAlY bond coat in previous studies.

  14. Study on hexaaluminate MnLaAl11O19-δcatalyst for catalytic combustive reaction of dimethyl ether as a new fuel

    Institute of Scientific and Technical Information of China (English)

    YU Qian; YU Lin; HUANG Yingmin; SUN Ming; CHEN Xiaokang; WANG Yuanna; ZHANG Qini

    2006-01-01

    Study on catalytic combustive reaction of dimethyl ether as a new fuel was presented. Hexaaluminate catalysts were used to reduce ignition temperature so that dimethyl ether completely combusted at low temperature. Hexaaluminate catalysts MnLaAl11O19-δ were prepared by reverse microemulsion method. Crystalline phase and structure of the catalyst were analysed by means of TG-DTA, XRD and BET. The results show that the hexaalunminate is of magnetoplumbite structure when La is taken as mirror plane cation. Hexaalunminate phase is formed slowly via 1050 ℃ calcined for 4 h and it can keep hexaaluminate phase and high surface area of 48 m2·g-1 even calcined at 1200 ℃ for 2h. Catalytic activity of MnLaAl11O19-δ was tested in combustion reaction of dimethyl ether. It shows that hexaaluminate is of high activity with T 10% at 170 ℃ and almost 100% conversion at 370 ℃.

  15. A Self-Propagating Foaming Process of Porous Al-Ni Intermetallics Assisted by Combustion Reactions

    Directory of Open Access Journals (Sweden)

    Makoto Kobashi

    2009-12-01

    Full Text Available The self-propagating foaming process of porous Al-Ni intermetallics was investigated. Aluminum and nickel powders were blended, and titanium and boron carbide powders were added as reactive exothermic agents. The blended powder was extruded to make a rod-shape precursor. Only one end of the rod precursor was heated to ignite the reaction. The reaction propagated spontaneously throughout the precursor. Pore formation took place at the same time as the reaction occurred. Adding the exothermic agent was effective to increase the porosity. Preheating the precursor before the ignition was also very effective to produce porous Al-Ni intermetallics with high porosity.

  16. Síntese de ZnAl2O4: Yb:Er por reação de combustão Synthesis of ZnAl2O4: Yb:Er by combustion reaction

    Directory of Open Access Journals (Sweden)

    J. F. Silva

    2006-09-01

    Full Text Available Aluminato de zinco dopado com os íons terras raras itérbio e érbio nas proporções 2:1, 3:1, 4:1, e 5:1 mol de Yb:Er foi sintetizado por reação de combustão. O efeito da dopagem simultânea Yb:Er na estrutura e na morfologia do aluminato de zinco foi investigado. Os pós foram sintetizados com base nos conceitos da química dos propelentes e então caracterizados por difração de raios X, análise granulométrica, adsorção de nitrogênio (método BET e microscopia eletrônica de varredura. Os resultados mostraram a formação da fase cristalina majoritária de ZnAl2O4:Yb:Er e traços das fases secundárias ZnO e Yb2O3 e que o aumento da relação Yb:Er favoreceu o aumento das fases secundárias. Todas as composições apresentaram morfologia formada por aglomerados moles constituídos por partículas finas. A área superficial aumentou em função da elevação da proporção Yb:Er.Zinc aluminate doped with ytterbium and erbium in the proportions 2:1, 3:1, 4:1, and 5:1 mol of Yb:Er were synthesized by combustion reaction. The effect of the Yb:Er in the structure and morphology of the zinc aluminate was investigated. The powders were synthesized on the basis of the propellants chemistry concepts and characterized by X-ray diffraction, nitrogen adsorption (BET method and scanning electron microscopy. The results show the formation of the ZnAl2O4:Yb:Er as majority crystalline phase and traces of ZnO and Yb2O3 as secondary phases, and that the increase of the Yb:Er proportion favored the increase of the content of secondary phases. All the compositions presented morphology formed by soft agglomerates of fine particles. The surface area increases with increasing Yb:Er proportion.

  17. Estrategias de crecimiento empresarial aplicadas por hipermercados

    Directory of Open Access Journals (Sweden)

    Miraidy Leal Morantes

    2003-01-01

    Full Text Available El presente estudio tiene como objetivo caracterizar las estrategias de crecimiento empresarial, representadas por alianzas y adquisiciones, que han sido aplicadas en el sector de distribución de bienes de consumo masivo, específicamente en los hipermercados ubicados en Maracaibo, Estado Zulia, como manera de responder al entorno competitivo y cambiante en el cual se desenvuelven. La investigación se desarrolló a través de un estudio de carácter descriptivo; para la recolección de datos se aplicó un cuestionario estructurado, bajo la modalidad de entrevista, a gerentes generales y financieros. Los resultados evidencian que las estrategias de crecimiento empresarial utilizadas son la apertura de nuevos establecimientos comerciales, adquisición de empresas y participación accionaria en grandes cadenas, las cuales propician la concentración del mercado de distribución comercial, afectando a algunas empresas venezolanas del sector cuya oferta no puede competir; asimismo, los proveedores se enfrentan a cadenas con gran poder de negociación.

  18. Luminescence of Ce doped MgAl{sub 2}O{sub 4} prepared by the combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Tabaza, W.A.I.; Swart, H.C.; Kroon, R.E., E-mail: KroonRE@ufs.ac.za

    2014-04-15

    Magnesium aluminate (MgAl{sub 2}O{sub 4}) has received special attention as a technologically important material because of its attractive properties, such as mechanical strength, chemical inertness, a wideband gap, relatively low density, high melting point, high thermal shock resistance, low thermal expansion coefficient, resistance to neutron irradiation and low dielectric loss. It has also been used as a phosphor host activated by a variety of transition metal and lanthanide ions. A simple combustion method was employed for the preparation of Ce doped MgAl{sub 2}O{sub 4} nanocrystals using metal nitrates as precursors and urea as a fuel in a preheated furnace at 520 °C. The as-prepared samples were annealed in a hydrogen atmosphere to improve their optical properties. The samples thus obtained were characterized by X-ray diffraction (XRD), UV–vis spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and photoluminescence spectroscopy (PL). The XRD data showed that all the samples had the spinel structure and the average particle size of the as-prepared samples was about 25 nm. PL spectra of Ce doped MgAl{sub 2}O{sub 4} using an excitation wavelength of 350 nm produced broad green emission bands centred at 500 nm. Maximum green emission was obtained for the sample doped with 0.75 mol% Ce. UV–vis diffuse reflectance spectra and XPS were used to obtain more information on the conversion of Ce ions from the non-luminescent Ce{sup 4+} to the luminescent Ce{sup 3+} charge state.

  19. Toxicología General y Aplicada

    OpenAIRE

    García Fernández, Antonio Juan

    2011-01-01

    Presentaciones de los temas de Toxicología General y Aplicada: clínica, alimentaria y ambiental impartidos en la asignatura de Toxicología de la licenciatura de Veterinaria en la Universidad de Murcia en el curso 2011/12. Presentaciones de los temas de Toxicología General y Aplicada: clínica, alimentaria y ambiental impartidos en la Facultad de Veterinaria en el curso 2011/12.

  20. CATALYTIC COMBUSTION OF METHANE OVER Pt/γ-Al2O3 IN MICRO-COMBUSTOR WITH DETAILED CHEMICAL KINETIC MECHANISMS

    Directory of Open Access Journals (Sweden)

    JUNJIE CHEN

    2014-11-01

    Full Text Available Micro-scale catalytic combustion characteristics and heat transfer processes of preheated methane-air mixtures (φ = 0.4 in the plane channel were investigated numerically with detailed chemical kinetic mechanisms. The plane channel of length L = 10.0 mm, height H =1.0 mm and wall thickness δ = 0.1 mm, which inner horizontal surfaces contained Pt/γ-Al2O3 catalyst washcoat. The computational results indicate that the presence of the gas phase reactions extends mildly the micro-combustion stability limits at low and moderate inlet velocities due to the strong flames establishment, and have a more profound effect on extending the high-velocity blowout limits by allowing for additional heat release originating mainly from the incomplete CH4 gas phase oxidation in the plane channel. When the same mass flow rate (ρin × Vin is considered, the micro-combustion stability limits at p: 0.1 MPa are much narrower than at p: 0.6 MPa due to both gas phase and catalytic reaction activities decline with decreasing pressure. Catalytic micro-combustor can achieve stable combustion at low solid thermal conductivity ks < 0.1 W∙m-1•K-1, while the micro-combustion extinction limits reach their larger extent for the higher thermal conductivity ks = 20.0-100.0 W∙m-1•K-1. The existence of surface radiation heat transfers significantly effects on the micro-combustion stability limits and micro-combustors energy balance. Finally, gas phase combustion in catalytic micro-combustors can be sustained at the sub-millimeter scale (plane channel height of 0.25 mm.

  1. La Antropología Aplicada en una Sociedad Compleja

    Directory of Open Access Journals (Sweden)

    Hugo Cadenas Ramos

    2005-01-01

    Full Text Available El presente artículo reflexiona sobre la definición del término antropología aplicada a la luz de los desafíos que enfrente la disciplina antropológica en el Siglo XXI, desde el punto de vista teórico, metodológico y de aplicación práctica en el más amplio sentido. Si bien el tema está abierto a debate y no se puede llegar a conclusiones taxativas, sí es posible proponer algunas ideas al debate.

  2. Hydrotalcite-derived MnxMg3-xAlO catalysts used for soot combustion, NOx storage and simultaneous soot-NOx removal.

    Science.gov (United States)

    Li, Qian; Meng, Ming; Xian, Hui; Tsubaki, Noritatsu; Li, Xingang; Xie, Yaning; Hu, Tiandou; Zhang, Jing

    2010-06-15

    The hydrotalcite-based Mn(x)Mg(3-x)AlO catalysts with different Mn:Mg atomic ratios were synthesized by coprecipitation, and employed for soot combustion, NOx storage and simultaneous soot-NO(x) removal. It is shown that with the increase of Mn content in the hydrotalcite-based Mn(x)Mg(3-x)AlO catalysts the major Mn-related species vary from MnAl(2)O(4) and Mg(2)MnO(4) to Mn(3)O(4) and Mn(2)O(3). The catalyst Mn(1.5)Mg(1.5)AlO displays the highest soot combustion activity with the temperature for maximal soot combustion rate decreased by 210 degrees C, as compared with the Mn-free catalyst. The highly reducible Mn(4+) ions in Mg(2)MnO(4) are identified as the most active species for soot combustion. For NO(x) storage, introduction of Mn greatly influences bulk NO(x) storage, with the adsorbed NO(x) species varying from linear nitrites to ionic and chelating bidentate nitrates gradually. The coexistence of highly oxidative Mn(4+) and highly reductive Mn(2+) in Mn(1.0)Mg(2.0)AlO is favorable to the simultaneous soot-NO(x) removal, giving a NO(x) reduction percentage of 24%. In situ DRIFTS reveals that the ionic nitrate species are more reactive with soot than nitrites and chelating bidentate nitrates, showing higher NO(x) reduction efficiency.

  3. Promotional effects of cerium doping and NOx on the catalytic soot combustion over MnMgAlO hydrotalcite-based mixed oxides

    Institute of Scientific and Technical Information of China (English)

    李倩; 王晓; 常伟; 陈慧; 张昭良

    2014-01-01

    A series of MnMgAlO samples with different amounts of Ce doping were facilely prepared using coprecipitation method and their catalytic soot combustion activity was evaluated by temperature programmed oxidation reaction (TPO). The methods of X-ray diffraction (XRD), Brumauer-Emmett-Teller (BET), H2-TPR, NO-TPO and in situ IR were used to characterize the physio-chemical properties of these samples. Dopant Ce improved the soot combustion performance of MnMgAlO catalyst due to the en-hanced redox ability. Introduction of NOx led to the further increase of catalytic soot oxidation activity on these samples. Over Ce-containing samples, the catalytic activity was slightly decreased as the amount of dopant Ce increased in O2. Differently, in NO+O2, a certain amount of dopant Ce was much more favorable and excess amount of Ce resulted in a sharp drop of the catalytic soot combustion activity. Both NO2 and nitrates were found to have great contributions to the effects of NOx on the soot combustion activity of Ce-doped catalysts. More NO2 was generated as dopant Ce increased. When appropriate amount of Ce was introduced, the as-formed NO2 was stored as bridging bidentate nitrate on Mn-Ce site, which was confirmed to have higher reactivity with soot than nitrite or monodentate nitrate on Mn and/or Ce sites. Overall, Mn0.5Mg2.5Ce0.1Al0.9O was considered as the most potential catalyst for soot combustion.

  4. Preparation of Non-Grinding Long Afterglow SrAl2O4:Eu2+, Dy3+ Material by Microwave Combustion Method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The non-grinding long afterglow material SrAl2O4:Eu2+, Dy3+ was prepared by combustion method in home microwave oven directly, after dispersant, frother, comburent, and mineralizer were added into the reacting system. XRD analysis showed that the powders were nearly pure SrAl2O4 phase with few other phases, and the size of the grain was 41.1 nm. Fluorescence spectrum results indicated that there were 2 excitation peaks located at 345 and 400 nm, and the emission peak located at 516 nm, afterglow lasted up to 30 min or more. The microwave combustion method has advantages of less time, low temperature and no grinding process, and the material made by the method has good luminescent property.

  5. Combustion synthesis: A suitable method to prepare Al{sub 2}O{sub 3} doped materials for thermoluminescent dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Vinicius S.M. de [Departamento de Energia Nuclear, Universidade Federal de Pernambuco, Recife-PE (Brazil)], E-mail: vdbarros@terra.com.br; Azevedo, Walter M. de [Laboratorio de Quimica do Estado Solido, CCEN, Universidade Federal de Pernambuco, Recife-PE (Brazil); Khoury, Helen J. [Departamento de Energia Nuclear, Universidade Federal de Pernambuco, Recife-PE (Brazil); Linhares Filho, Pedro [Curso de Ciencia dos Materiais, CCEN, Universidade Federal de Pernambuco, Recife-PE (Brazil)

    2008-02-15

    In this work we present an alternative route to synthesize rare-earth doped aluminum oxide materials for thermoluminescent (TL) dosimetry using the combustion synthesis (CS) technique. The samples were prepared by mixing aluminum nitrate (Al(NO{sub 3}){sub 3}.9H{sub 2}O), urea (CO(NH{sub 2}){sub 2}), and europium nitrate (Eu(NO{sub 3}){sub 3}), terbium nitrate (Tb(NO{sub 3}){sub 3}) and tetra-ethyl-ortho-silicate (TEOS, C{sub 8}H{sub 20}O{sub 4}Si) in appropriate amounts as dopants in an aqueous solution. The excess water was evaporated on a hot plate to form a gelatinous mixture, which was then transferred to a muffle furnace pre-heated to 500 deg. C where it ignited spontaneously within a few seconds. The TL glow curve of the irradiated samples showed an isolated peak at around 200 deg. C for the Eu doped sample which is suitable for radiation dosimetry. The europium concentration was varied from 0.005% to 7% in order to study the effect of the dopant concentration on the TL response and the optimum concentration was found to be 0.5%. The effect of different annealing temperatures of the sample on the TL response was also studied and the results showed a broad TL peak for 600 and 800 deg. C and a well defined peak for a 1000 deg. C annealing temperature. From these results it is possible to conclude that the CS method is a very suitable technique to prepare doped aluminum oxide materials. The technique is fast, low cost and produces well defined materials that can be used for dosimetric applications. Further work is still under way in order to optimize sensitivity for low dose measurements.

  6. Investigation on the Combustion Behavior of CMDB Propellant with Mg/Al Alloy%Mg/Al合金对CMDB推进剂燃烧性能的影响

    Institute of Scientific and Technical Information of China (English)

    吴雄岗; 宋桂贤; 严启龙; 李笑江; 党永战; 张晓宏

    2012-01-01

    The particle size and distribution of particle size of Mg/Al were analyzed by Mastersizer. The thermal characterisitics of CDMB propellant were analyzed by TG-DSC. The flame structure was studied by using the burning device and the differences of the flame structure were compared amongst CMDB, Al-CMDB, Mg-CMDB and Mg/Al-CMDB propellants. The surface appearance of the propellant quenched and surface composition were researched by the SEM and EDS. The results show that the Mg/Al alloy has a peak 630.3℃ of the heat of CMDB propellant. The combustion condition of CMDB propellant with Mg/Al is changed. Meanwhile,the metallic Al fuel combustion efficiency is improved.%通过激光粒度仪分析了Mg/Al合金粉的粒径及粒度分布。利用TG-DSC热分析仪分析推进剂的热分解特性。用燃烧实验装置研究了推进剂的火焰结构,并对CMDB,Al-CMDB,Mg-CMDB和Mg/Al-CMDB推进剂四种火焰结构进行比较。用SEM和EDS研究了CMDB推进剂的熄火表面形貌和表面特征组成。结果表明:Mg/Al-CM-DB推进剂在DSC曲线上存在一放热峰660.3℃。Mg/Al合金粉改变了推进剂的燃烧状态,提高金属燃料Al粉的燃烧效率。

  7. A música terapêutica como uma tecnologia aplicada ao cuidado e ao ensino de enfermagem La música terapéutica como una tecnología aplicada al cuidado y a la enseñanza de la enfermería Therapeutic music as a technology applied to healthcare and to the nursing teaching

    Directory of Open Access Journals (Sweden)

    Leila Brito Bergold

    2009-09-01

    Full Text Available A predominância das técnicas na assistência muitas vezes inviabiliza o estabelecimento de um cuidado expressivo que promova a humanização da prática assistencial. Este estudo abordou duas pesquisas que investigaram o uso da música como um recurso terapêutico aplicado ao cuidado e ao ensino de enfermagem: a visita musical e a dinâmica musical. Ancorou-se nas contribuições de Even Ruud sobre o contexto cultural relacionado à música e à saúde. Utilizou-se o Método Criativo-Sensível na produção de dados das duas pesquisas, realizadas respectivamente com clientes hospitalizados e enfermeiros. A visita musical constituiu-se como tecnologia para o cuidado expressivo, pois promoveu conforto, ludicidade, expressão emocional e integração entre os clientes e destes com o ambiente hospitalar. A dinâmica musical mobilizou a produção de subjetividades nos enfermeiros, que perceberam as possibilidades do uso criativo da música como um recurso tanto no âmbito do cuidado quanto no ensino de enfermagem.El predominio de la técnica en los cuidados y asistencia muchas veces dificulta el establecimiento de un cuidado expresivo que promueva la humanización de la práctica asistencial. Este estudio abordó dos pesquisas que investigaron el uso de la música como un recurso terapéutico aplicado al cuidado y a la enseñanza de la enfermería: la visita musical y la dinámica musical. Se basó en las contribuciones de Even Ruud sobre el contexto cultural relacionado a la música y a la salud. Se utilizó el Método Creativo-Sensible en la producción de datos de las dos pesquisas, realizadas respectivamente con clientes hospitalizados y enfermeros. La visita musical se constituyó como una tecnología para el cuidado expresivo, al promover bienestar, entretenimiento, expresión emocional y la integración entre los pacientes con el ambiente de hospital. La dinámica musical movilizó la producción de subjetividades en los enfermeros, quienes

  8. Synthesis and characterization of Sr_3Al_2O_6:Eu~(2+), Dy~(3+)phosphors prepared by sol-gel-combustion processing

    Institute of Scientific and Technical Information of China (English)

    Huang Ping; Cui Cai-E; Wang Sen

    2009-01-01

    A type of red luminescent Sr_3Al_2O_6:Eu~(2+), Dy~(3+) phosphor powder is synthesised by sol-gel-combustion processing, with metal nitrates used as the source of metal ions and citric acid as a chelating agent of metal ions. By tracing the formation process of the sol-gel, it is found that it is necessary to reduce the amount of NO_3~- by dropping ethanol into the solution for forming a stable and homogeneous sol-gel. Thermogravimetric and Differential Scanning Calorimeter Analysis, x-ray diffractionmeter, scanning electron microscopy and pbotoluminescence spectroscopy are used to investigate the luminescent properties of the as-synthesised Sr_3Al_2O_6:Eu~(2+), Dy~(3+). The results reveal that the Sr_3Al_2O_6 crystallises completely when the combustion ash is sintered at 1250 ℃. The excitation and the emission spectra indicate that the excitation broadband lies mainly in a visible range and the phosphors emit a strong light at 618 nm under the excitation of 472 nm. The afterglow of (Sr_(0.94)Eu_(0.03)Dy_(0.03))_3Al_2O_6 phosphors sintered at 1250 ℃ lasts for over 1000s when the excited source is cut off.

  9. Biotecnologia aplicada ao desenvolvimento de vacinas

    Directory of Open Access Journals (Sweden)

    Mariana de Oliveira Diniz

    2010-01-01

    Full Text Available As vacinas representam a estratégia de intervenção com a melhor relação custo-benefício até hoje aplicada em saúde pública. Avanços biotecnológicos em diversas áreas de pesquisa têm contribuído para o desenvolvimento de formulações mais seguras e eficazes. Além disso, a aplicação de ferramentas biotecnológicas no desenvolvimento de vacinas tem provocado mudanças na maneira como pensamos e produzimos esses reagentes tanto para uso em humanos como em animais. Essas tecnologias trazem perspectivas de que, em futuro próximo, vacinas para o controle de doenças infecciosas e degenerativas ainda não passíveis de prevenção possam estar disponíveis. Em particular, vacinas com efeitos terapêuticos, embora representem um enorme desafio a ser vencido, tornam-se cada vez próximas da realidade e, certamente, terão um impacto enorme no tratamento de diversas doenças, como em algumas formas de câncer.Vaccines represent the intervention strategy with the best cost-benefit ratio so far applied in public health. Biotechnological advances in various areas of vaccine research have contributed to the development of safer and more effective formulations. Moreover, application of biotechnology tools to vaccine development has caused changes in the way we think and produce these reagents both for use in humans and animals. Such technologies bring renewed perspectives that, in the near future, vaccines for the control of several non-preventable infectious and degenerative diseases will be available. In particular, the development of vaccines with therapeutic effects, although representing a huge challenge, are getting closer to reality and will have a tremendous impact in the treatment of several diseases such as some cancer forms.

  10. N-doped P25 TiO2-amorphous Al2O3 composites: one-step solution combustion preparation and enhanced visible-light photocatalytic activity.

    Science.gov (United States)

    Li, Fa-tang; Zhao, Ye; Hao, Ying-juan; Wang, Xiao-jing; Liu, Rui-hong; Zhao, Di-shun; Chen, Dai-mei

    2012-11-15

    Nitrogen-doped Degussa P25 TiO2-amorphous Al2O3 composites were prepared via facile solution combustion. The composites were characterised using X-ray diffraction, high-resolution transmission microscopy, scanning electron microscopy, nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy, UV-vis light-diffusion reflectance spectrometry (DRS), zeta-potential measurements, and photoluminescence spectroscopy. The DRS results showed that TiO2 and amorphous Al2O3 exhibited absorption in the UV region. However, the Al2O3/TiO2 composite exhibited visible-light absorption, which was attributed to N-doping during high-temperature combustion and to alterations in the electronic structure of Ti species induced by the addition of Al. The optimal molar ratio of TiO2 to Al2O3 was 1.5:1, and this composite exhibited a large specific surface area of 152 m2/g, surface positive charges, and enhanced photocatalytic activity. These characteristics enhanced the degradation rate of anionic methylene orange, which was 43.6 times greater than that of pure P25 TiO2. The high visible-light photocatalytic activity was attributed to synthetic effects between amorphous Al2O3 and TiO2, low recombination efficiency of photo-excited electrons and holes, N-doping, and a large specific surface area. Experiments that involved radical scavengers indicated that OH and O2- were the main reactive species. A potential photocatalytic mechanism was also proposed.

  11. Determination of intermediates and mechanism for soot combustion with NOx/O₂ on potassium-supported Mg-Al hydrotalcite mixed oxides by in situ FTIR.

    Science.gov (United States)

    Zhang, Zhaoliang; Zhang, Yexin; Su, Qingyun; Wang, Zhongpeng; Li, Qian; Gao, Xiyan

    2010-11-01

    The soot combustion with NO(x) and/or O(2) on potassium-supported Mg-Al hydrotalcite mixed oxides under tight contact condition was studied using temperature-programmed oxidation (TPO), isothermal reaction and in situ FTIR techniques. The presence of NO(x) in O(2) favors the soot combustion at lower temperatures (300 °C), which was accompanied by a substantial NO(x) reduction. The ketene (C═C═O) and isocyanate (NCO(-)) species were determined as the reaction intermediates. In NO(x) + O(2), NO(2) directly interacts with the free carbon sites (C═C*) through two parallel reactions: (1) NO(2) + C═C* → C═C═O + NO; (2) NO(2) + C═C* → NCO(-) + CO(2). The two reactions can proceed easily, which accounts for the promotion effect of NO(x) on soot combustion at lower temperatures. The further oxidation of NCO(-) by NO(2) or O(2) is responsible for the simultaneous reduction of NO(x). However, the reactions between NO(2) and C═C* are limited by the amount of free carbon sites, which can be provided by the oxidation of soot by O(2) at higher temperatures. The interaction of NO(x) and catalyst results in the formation of nitrates and nitrites, which poisoned the active K sites.

  12. Nuevas metodologías docentes aplicadas al estudio de la fisiología y la anatomía: estudio comparativo con el método tradicional

    OpenAIRE

    Gal Iglesias, Beatriz; Busturia Berrade, Ignacio; Garrido Astray, María Concepción

    2009-01-01

    El estudio integrado de la fisiología y la anatomía constituye una asignatura troncal dentro de las titulaciones de ciencias de la salud. La adaptación de la enseñanza de esta materia al estándar de Bolonia supone un reto metodológico dada su complejidad curricular y sus perfiles competenciales específicos. Se pretende evaluar experimentalmente una metodología mixta en la enseñanza de la fisiología y anatomía tanto en los resultados del aprendizaje como en la adquisición de competencias de lo...

  13. Spectroscopic study and enhanced thermostability of combustion-derived BaMgAl10O17:Eu2+ blue phosphors for solid-state lighting

    Science.gov (United States)

    Pradal, Nathalie; Potdevin, Audrey; Chadeyron, Geneviève; Bonville, Pierre; Caillier, Bruno; Mahiou, Rachid

    2017-02-01

    Blue-emitting BaMgAl10O17:Eu2+ (BAM:Eu), suitable for applications in a next generation of Hg-free lamps based on UV LEDs, was prepared by a microwave induced solution combustion synthesis, using urea as combustion fuel and nitrates as oxidizers. Purity control of the as-synthesized blue phosphor was undertaken by a washing step followed by a reduction one. Structural and morphological properties of the outcoming phosphors have been considered. Synthesis process allows producing a well-crystallized and nanostructured BAM phase within only few minutes. The influence of reduction treatment on the relative amounts of Eu2+/Eu3+ in our samples has been investigated through an original study by magnetization and Mössbauer spectroscopy. Furthermore, a complete optical study has been carried out and allowed us to determine the europium localization in the three possible sites in BAM matrix. The percentage of Eu2+ increased twofold after the reduction treatment, entailing an increase in the luminescence efficiency upon UV excitation. Finally, temperature-dependent luminescence of combustion-derived powders has been studied till 170 °C and compared to that of commercial BAM:Eu. MISCS-derived phosphors present a higher thermal stability than commercial one: whereas the emission efficiency of this last was reduced by 64%, the one of combustion-derived BAM:Eu experienced an only 12% decline. Furthermore, while commercial BAM suffered from a severe blue-shift with increasing temperature, our phosphors keep its color quality with a good stability of the photometric parameters.

  14. Una propuesta para incrementar la capacidad discriminante de las técnicas PCA y LDA aplicadas al reconocimiento de rostros con imágenes IR A Proposal to increase by genetic algorithm the discriminatory

    Directory of Open Access Journals (Sweden)

    Eduardo Caicedo B

    2011-06-01

    Full Text Available Dos de las técnicas más ampliamente utilizadas en el campo del reconocimiento de rostros con imágenes infrarrojas son PCA (Principal Component Analisys y LDA (Linear Discriminant Analysis. En este trabajo se presentan los resultados obtenidos al emplear algoritmos genéticos para incrementar el poder discriminante de los vectores que conforman el espacio de características generado por dichas técnicas, por medio de la asignación ponderada de pesos a cada vector según su nivel de aporte en la etapa de clasificación. Se muestra que bajo el esquema propuesto, se obtiene un menor error de clasificación respecto al método convencional.PCA and LDA are two of most widely used techniques for face recognition with IR images. In this paper we report the results obtained by using Genetics Algorithms for optimization the characteristic vector generated by these techniques, by assignation of weights to each vector according its performance in the classification task. It shows that, under the proposed scheme, is able to obtain a lower classification error compared to conventional method.

  15. Redefiniendo el trabajo metodológico cualitativo con niños: el uso de la entrevista de grupo aplicada al estudio de la tecnología

    Directory of Open Access Journals (Sweden)

    IVÁN RODRÍGUEZ PASCUAL

    2006-01-01

    Full Text Available La población infantil ha sido un colectivo tradicionalmente ignorado por la investigación sociológica, siendo escasa la práctica investigadora que ha considerado al niño como unidad de observación e informante válido. Aquí damos cuenta de la utilidad del estudio del discurso infantil a través de la entrevista grupal; técnica que pretende, precisamente, evitar el sesgo adultocéntrico de la disciplina. Se ilustra la utilidad de la misma a través de un caso real referido al estudio de la manera en que los menores construyen un uso particular de las nuevas tecnologías de la información y la comunicación. Concluimos que la entrevista grupal permite el libre desarrollo de la voz del niño y resulta especialmente adecuada para desvelar los aspectos latentes u ocultos que pueden estar involucrados en la reconstrucción del sentido del mundo adulto por parte de los menores de edad.

  16. Synthesis of Y1-xAlxBa2Cu3O7-δ via combustion route: Effects of Al2O3 nanoparticles on superconducting properties

    Science.gov (United States)

    Mohd Suan, Mohd Shahadan; Johan, Mohd Rafie

    2017-02-01

    Combustion reaction was used to synthesis Al2O3 nanoparticles embedded Y1-xAlxBa2Cu3O7-δ simultaneously. The effects of Al2O3 nanoparticles with nominal molar mass (xmol) of 0.02, 0.04, 0.06, 0.08 and 0.10 towards the critical current density JC of Y1-xAlxBa2Cu3O7-δ were verified by magnetic measurement. Resulted XRD patterns revealed that the calcined samples consist of pure Al2O3 and Y1-xAlxBa2Cu3O7-δ phases which had been confirmed by EDX results. The SEM images showed that Al2O3 nanoparticles ( 10 nm) were distributed in polycrystalline YBa2Cu3O7-δ grains and grain boundaries. The presence of higher concentration of Al2O3 nanoparticles has developed Al3+ rich spots which diffused within the YBa2Cu3O7-δ superconducting matrix to form Y1-xAlxBa2Cu3O7-δ and was confirmed by EDX analysis. The samples were electrically superconducting at temperature above 85 K as measured by using standard four-probe technique. The magnetic field (H) dependent magnetization (M), M-H hysteresis loops measured at 77 K for xmol≤0.06 samples are significantly improved attributed to the increase of trapped fluxes in the samples. Remarkable increase of magnetic JC (H) in Al2O3 nanoparticles added samples compared to the as prepared polycrystalline YBa2Cu3O7-δ sample indicating strong pinning effect. It is suggested that well-distributed Al2O3 nanoparticles in the polycrystalline YBa2Cu3O7-δ matrix achieved via auto-combustion reaction has efficiently pin the magnetic vortex. The magnetic JC was optimized to 6 kAcm-2 in xmol=0.06 sample. On the other hand, insignificant magnetic JC improvement in xmol≥0.08 samples is probably resulted from the agglomerated Al2O3 nanoparticles in Y1-xAlxBa2Cu3O7-δ phase.

  17. Tailoring a High Temperature Corrosion Resistant FeNiCrAl for Oxy-Combustion Application by Thermal Spray Coating and HIP

    Directory of Open Access Journals (Sweden)

    Jarkko Metsäjoki

    2015-10-01

    Full Text Available Oxy-fuel combustion combined with CCS (carbon capture and storage aims to decrease CO2 emissions in energy production using fossil fuels. Oxygen firing changes power plant boiler conditions compared to conventional firing. Higher material temperatures and harsher and more variable environmental conditions cause new degradation processes that are inadequately understood at the moment. In this study, an Fe-Ni-Cr-Al alloy was developed based on thermodynamic simulations. The chosen composition was manufactured as powder by gas atomization. The powder was sieved into two fractions: The finer was used to produce thermal spray coatings by high velocity oxy-fuel (HVOF and the coarser to manufacture bulk specimens by hot isostatic pressing (HIP. The high temperature corrosion properties of the manufactured FeNiCrAl coating and bulk material were tested in laboratory conditions simulating oxy-combustion. The manufacturing methods and the results of high temperature corrosion performance are presented. The corrosion performance of the coating was on average between the bulk steel references Sanicro 25 and TP347HFG.

  18. Blue-green BaAl2O4:Eu2+,Dy3+ phosphors synthesized via combustion synthesis method assisted by microwave irradiation

    Institute of Scientific and Technical Information of China (English)

    SUN Feilong; ZHAO Junwu

    2011-01-01

    Blue-green luminescent BaAl2O4:Eu2+,Dy3+ phosphor powders were synthesized via combustion synthesis method assisted by microwave irradiation in air. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The XRD results revealed that when the concentration of urea was over 3 times higher than theoretical quantities, a BaAl2O4 single hexagonal phase was obtained. The SEM results revealed that the surface of the BaAl2O4:Eu2+,Dy3+ powder samples showed lots of voids and pores. The BaAl2O4:Eu2+,Dy3+ phosphors exhibited a broad emission band of main peak at 496 nm and a shoulder peak at 426 nm under excitation of 337 nm. The BaAl2O4:Eu2+,Dy3+ phosphors at the Eu2+ concentration of 1 mol.% showed the strongest luminescent intensity. Long afterglow phosphorescence was observed in the dark with naked eyes after the removal of the excitation source.

  19. Teoría de la incertidumbre aplicada al valor del cliente en situaciones contractuales con intervalos de confianza = The Uncertainty Theory assignment in the Customer Lifetime Valuation (CLV for contractual settings with security intervals

    Directory of Open Access Journals (Sweden)

    Merigó, José M.

    2007-01-01

    Full Text Available El valor del consumidor ha sido un concepto muy estudiado desde hace tiempo por investigadores en las áreas de marketing. La mayoría de estas investigaciones están basadas en supuestos deterministas o aleatorios, al medir magnitudes o eventos que intervienen en el cálculo del valor del cliente. En muchas ocasiones, los modelos del valor del consumidor en los que se involucran magnitudes que hacen referencia al futuro, por el entorno regido por su mutabilidad y por la incertidumbre, resultan excesivamente precisos para poder reflejar la realidad. Kaufmann y Gil Aluja (1986, que son dos de los precursores e investigadores más notables en Europa en las técnicas operativas de gestión, sostenían que “lo impreciso, lo borroso, no tiene por qué ser inexacto”. Podemos trabajar con modelos en los que tradicionalmente se utilizan cifras precisas pero no son necesariamente exactos. En la investigación que nos ocupa, proponemos las aportaciones necesarias para utilizar cifras inciertas, borrosas, pero más adecuadas a la realidad. Vamos a presentar, para ello, dos modelos del valor del cliente (CLV con la herramienta menos estructurada de la teoría de la incertidumbre: los intervalos de confianza, con la finalidad de ayudar a trabajar magnitudes inciertas involucradas en el cálculo del CLV. = The Customer Lifetime Value (CLV concept has been highly purposed in many researches in the marketing area since long time ago. Almost all of them tend to be based on determinist or stochastic assumptions when measuring magnitudes or events which have to do with CLV estimates. Often, the Customer Lifetime Valuation (CLV involves magnitudes that link to the future by the running environment, its mutability and uncertainty, and this turn out the results to be too accurate. Kaufman and Gil Aluja (1986, who are the two most well known European investigators, have carried out researches into several operative management techniques, stood by the following

  20. Estrategias de Enseñanza a Distancia sobre Control No-Lineal Aplicada al Péndulo Invertido Strategies for Distance Learning Courses on Nonlinear Control Applied to the Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Sergio García-Nieto

    2007-01-01

    Full Text Available Este artículo describe el desarrollo de una herramienta software/hardware destinada al estudio, en el ámbito de la enseñanza universitaria, de sistemas de control distribuidos en tiempo real. El sistema se empleará en el control de procesos no lineales. Esta herramienta presenta tres partes claramente diferenciadas, las cuales pueden ser analizadas y modificadas por los estudiantes: i se introduce el modelo físico del péndulo invertido; ii el controlador es implementado en un sistema distribuido de tiempo real; y iii todo el sistema es manejado mediante una aplicación desarrollada en JAVA. Por lo tanto, los estudiantes tienen todos los elementos necesarios para trabajar con sistemas complejos no lineales, como el problema del péndulo invertido que se discute en este trabajo. Las pruebas realizadas muestran que la plataforma proporciona un método rápido y seguro de experimentación para los estudiantes.This paper presents a software/hardware tool to study, at university level, distributed control systems in real time. This platform is applied to control nonlinear processes. The system has three different parts which students can evaluate and modify; i a virtual model represents the physic model of the inverted pendulum; the controller is implemented by a real time distributed control system; and iii the whole system is managed with a JAVA application. Therefore, students have all the necessary elements to practice with complex nonlinear systems, such as the inverted pendulum discussed in this work. The tests done show that the plattform represents a fast and reliable method for experimentation by the students.

  1. Herramientas biotecnológicas aplicadas al estudio del cáncer: el modelo de cáncer de cuello uterino y su relación con el virus del papiloma humano (hpv

    Directory of Open Access Journals (Sweden)

    Orozco O.

    1999-12-01

    Full Text Available El Cáncer de cuello uterino es un problema de salud pública mundial, con más de 500.000 nuevos casos al año y 200.000 muertes, 80% de los cuales ocurren en países del tercer mundo. Las evidencias morfológicas, epidemiológicas y moleculares indican que la infección por el virus del Papiloma Humano (HPV está fuertemente asociada con el desarrollo del tumor. El estudio del papel del virus es importante tanto desde el punto de vista de la comprensión del proceso carcinogénico en sí, como desde la perspectiva de la implementación de medidas que previniendo o controlando la infección viral, puedan llevar a evitar la aparición del cáncer y/o controlar su crecimiento. Hasta hace poco, estos estudios se vieron limitados por la dificultad de obtener material viral suficiente, ya sea de las lesiones o por medio de cultivo «in vitro» de células infectadas. Los avances recientes en las técnicas inmunológicas, de ingeniería genética y de síntesis química han permitido aplicar una perspectiva biotecnológica en este modelo, lográndose un conocimiento muy importante de los mecanismos carcinogénicos vírales y de la interacción virus-huésped en el ámbito de la respuesta inmune. Lo anterior ha permitido proponer por ejemplo la vacunación con fines profilácticos (evitar la infección viral primaria y por ende la aparición del tumor o con fines terapéuticos (eliminación inmunológica de células ya infectadas y tumorales. En nuestro laboratorio hemos empleado estas técnicas para producir anticuerpos monoclonales anti-péptidos sintéticos derivados de la secuencia de la oncoproteína E7 de HPV 16, para buscar con esta herramienta la caracterización de la protema nativa, su detección en tejidos tumorales y entender mejor su papel en el proceso oncogénico. También hemos logrado introducir el gen de esta proteína en un vector plasmídico, expresando posteriormente el producto en bacterias y obteniendo así el material

  2. Generación automática de variantes de trayectorias aplicada al diseño óptimo bajo criterios múltiples de redes hidráulicas de abasto.

    Directory of Open Access Journals (Sweden)

    J. R. Hechavarría Hernández

    2007-05-01

    Full Text Available La determinación de las trayectorias más eficientes que deben tener las redes, instalaciones o vías de transporte es un problema que motiva a muchos investigadores de diversas ingenierías: informática, civil, mecánica, hidráulica, etc., cuyas soluciones requieren ser realizadas sobre la base de la elevada integración de la información durante el proceso de análisis y estudio de la tarea, de la aplicación de los métodos modernos de preparación y toma de decisiones, así como la organización racional de los procedimientos de cálculo de ingeniería. Para definir el trazado de trayectorias en los proyectos de ingeniería se tienen en cuenta determinadas condiciones propias del entorno. Estas trayectorias, pese a su diferente designación, pueden coincidir en determinadas zonas y compartir espacios limitados. Por esta razón, un sistema para la generación automática de variantes de trayectorias deberá considerar las limitaciones del espacio disponible al establecer el tipo y dimensiones límites. En el artículo se presenta un procedimiento que apoyado en un sistema informático permite obtener de manera automática variantes de trayectorias cerradas las cuales dependiendo de su destino de servicio serán optimizadas bajo criterios de eficiencias.Determining the most efficient trajectories of networks, installations or transportation roads is a problem to a lot of investigators of different fields: Computer Science, Civil Engineering, Mechanical Engineering, Hydraulics, etc. Solutions should be carried out taking into account a high integration of information in the analysis and study process of the task, the application of the modern methods of preparation and decision making, as well as the rational organization of the procedures of engineering calculation. Several conditions regarding the surroundings are taken into account in engineering projects while defining the layout of trajectories. These trajectories, in spite of their

  3. La epistemología de reichenbach aplicada al desarrollo de trabajos prácticos contextualizados (TPC Reichenbach's epistemology applied to the development of context practical work (CPW

    Directory of Open Access Journals (Sweden)

    Cristina T. Speltini

    2006-04-01

    Full Text Available El presente trabajo describe la aplicación, durante tres cuatrimestres, de una innovación didáctica en el enfoque de los trabajos experimentales de un curso de Física para Ingeniería. El objetivo de la innovación fue trabajar en contextos, desde una ampliación de la perspectiva epistemológica de Reichenbach. Se planteó la enseñanza de temas de Física integrando los contextos: de descubrimiento, de justificación y de aplicación. Se observó que los trabajos experimentales contextualizados permiten extender la lógica disciplinar al relacionar aspectos históricos, epistemológicos, didácticos y tecnológicos del conocimiento enseñado. Una encuesta de opinión permitió conocer las ideas de los estudiantes sobre la innovación; los resultados obtenidos se muestran en el presente trabajo. Se advirtió que la implementación sistemática de esta innovación requeriría una organización curricular diferente, por lo menos en los cursos de Física para Ingeniería.This paper presents a didactic innovation applied to the experimental work within a course of Physics for Engineers, during a period of three terms. The aim of this innovation was to work with “context” from an extended Reichenbach epistemological perspective. Physics concepts were taught, integrating the following contexts: discovery, justification, teaching and employment. It was noticed that when contexts are applied to experimental work, the disciplinary logic is broadened, as a result of linking historical, epistemological and technological aspects of the subject being taught. The students ideas about the innovation were gathered through a questionnaire and the results are included in this work. The systematic use of this innovation would require a different curricular organization at least in Physics courses for engineers.

  4. Nuevas metodologías docentes aplicadas al estudio de la fisiología y la anatomía: estudio comparativo con el método tradicional

    Directory of Open Access Journals (Sweden)

    B. Gal-Iglesias

    Full Text Available Introducción. El estudio integrado de la fisiología y la anatomía constituye una asignatura troncal dentro de las titulaciones de ciencias de la salud. La adaptación de la enseñanza de esta materia al estándar de Bolonia supone un reto metodológico dada su complejidad curricular y sus perfiles competenciales específicos. Objetivos. Evaluar experimentalmente una metodología mixta en la enseñanza de la fisiología y anatomía tanto en los resultados del aprendizaje como en la adquisición de competencias de los alumnos, así como desarrollar un baremo de medición del aprendizaje. Sujetos y métodos. Se comparan los resultados del aprendizaje en la diplomatura de podología de la Universidad Europea de Madrid entre un grupo control (metodología clásica: lección magistral y uno experimental (metodología mixta: problemas, casos clínicos, trabajo en grupo y lección magistral. Resultados. Se muestra que con una aproximación mixta los alumnos adquieren habilidades y competencias a lo largo del curso, estabilizándose el aprendizaje lo suficiente y equilibrándose las diferencias individuales, en contraste con el grupo control. Esta homogeneización del aprendizaje se manifiesta como una menor variabilidad de la nota media de los exámenes en el grupo experimental, e indica el soporte que supone el método mixto para el aprendizaje de los alumnos con mayores dificultades. Se detecta una fuerte regresión lineal entre la asistencia a clase y los resultados del aprendizaje, y se confirma la importancia de la supervisión del proceso de aprendizaje por parte del profesor. Conclusión. El método mixto de enseñanza de la fisiología y la anatomía permite a los alumnos adquirir habilidades y competencias a lo largo del curso, equilibrando las diferencias como parte del proceso de aprendizaje.

  5. Facile combustion synthesized orthorhombic GdAlO{sub 3}:Eu{sup 3+} nanophosphors: Structural and photoluminescence properties for WLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Jisha, P.K.; Naik, Ramachandra [Department of Physics, New Horizon College of Engineering, Bangalore 560103 (India); Research and Development Center, Bharathiar University, Coimbatore 641046 (India); Prashantha, S.C., E-mail: scphysics@gmail.com [Research and Development Center, Bharathiar University, Coimbatore 641046 (India); Department of Science, East West Institute of Technology, Bangalore 560091 (India); Nagabhushana, H., E-mail: bhushanvlc@gmail.com [Center for Advanced Materials, Tumkur University, Tumkur 572103 (India); Sharma, S.C. [Chattisgarh Swamy Vivekananda Technical University, Bhilai, CG 493441 (India); Nagaswarupa, H.P.; Anantharaju, K.S. [Department of Science, East West Institute of Technology, Bangalore 560091 (India); Prasad, B. Daruka [Department of Physics, B M S Institute of Technology, Yelahanka, Bangalore 560064 (India); Premkumar, H.B [Department of Physics, Acharya Institute of Technology, Bangalore 560107 (India)

    2015-07-15

    Nanoparticles of Eu{sup 3+} doped (1–11 mol%) GdAlO{sub 3} were prepared using low temperature (350 °C) solution combustion technique with gadalonium nitrate as oxidizer and oxalyl di-hydrazide (ODH) as a fuel. The synthesized samples were calcined at 1000 °C for 3 h and used for Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and UV–visible absorption (UV–vis) characterization techniques. A pure orthorhombic was obtained in calcined samples. The average crystallite sizes were estimated using Scherrer's formula, W–H and size–strain plots and found to be in the range 25–50 nm and the same was confirmed by Transmission electron microscopy (TEM) studies. The phosphors exhibit bright red emission upon 395 nm excitation. The characteristic emission peaks recorded at ~591, 612, 654 and 694 nm ({sup 5}D{sub 0}→{sup 7}F{sub j=1,2,3,4}) were attributed to the 4f–4f intra-shell transitions of Eu{sup 3+} ions. The CIE chromaticity co-ordinates were calculated from emission spectra, the values (x, y) were very close to NTSC standard value of red emission. Further, the average CCT value was found to be ~2369 K, as a result the prepared nanophosphor was highly useful for red component of white light emitting devices and also for solid state display applications. - Highlights: • Propellant facile combustion technique is used to prepare GdAlO{sub 3}:Eu{sup 3+}. • PL of GdAlO{sub 3}:Eu{sup 3+} nanophosphor show characteristic emission at 612 nm ({sup 5}D{sub 0}→{sup 7}F{sub 2}). • CIE and CCT show average emission in red region. • Present phosphor was quite useful for display applications.

  6. Surface structure and catalytic performance of Sr-doped La2NiAlO6 double perovskite catalysts for methane combustion

    Institute of Scientific and Technical Information of China (English)

    胡瑞生; 白雅琴; 杜航宇; 张慧敏; 杜燕飞; 张俊阁; 周啟华

    2015-01-01

    A species of novel Sr-doped rare earth double perovskite catalysts (La2–xSrxNiAlO6,x=0, 0.1) were prepared by the sol-gel method using citric acid as a complexing agent and calcined at 1100 ºC for 3 h, then investigated for methane catalytic combustion. The as-prepared catalysts were characterized by X-ray diffraction patterns (XRD), H2-temperature-programmed reduction (H2-TPR), specific surface area (BET), magnetic property measurement technology (M-H), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Experimental results showed that La1.9Sr0.1NiAlO6 catalyst exhibited significantly improved cata-lytic activity (T10=378.7 ºC,T90=602.9 ºC) compared with that of La2NiAlO6, whoseT10 decreased by 74.4 ºC andT90 decreased by 66.8 ºC, respectively. The excellent catalytic activity of La1.9Sr0.1NiAlO6caused by Sr-doping could be explained by the larger num-ber of adsorption oxygen on the catalyst surface, which could be proven by XPS analysis.

  7. A novel synthetic route for magnesium aluminate (MgAl2O4) nanoparticles using sol-gel auto combustion method and their photocatalytic properties

    Science.gov (United States)

    Nassar, Mostafa Y.; Ahmed, Ibrahim S.; Samir, Ihab

    2014-10-01

    In this paper a novel and inexpensive route for the preparation of spinel magnesium aluminate nanoparticles (MgAl2O4) is proposed. Magnesium aluminate photocatalyst was synthesized via sol-gel auto combustion method using oxalic acid, urea, and citric acid fuels at 350 °C. Subsequently, the burnt samples were calcined at different temperatures. The pure spinel MgAl2O4 with average crystallite size 27.7, 14.6 and 15.65 nm was obtained at 800 °C calcinations using the aforementioned fuels, respectively. The obtained samples were characterized by powder X-ray diffraction, Fourier transform infrared, UV-Vis spectroscopy, transmission electron microscope, scanning electron microscope. The photo catalytic activity of MgAl2O4 product was studied by performing the decomposition of Reactive Red Me 4BL dye under UV illumination or sunlight irradiation. The dye considerably photocatalytically degraded by 90.0% and 95.45% under UV and sunlight irradiation, respectively, within ca. 5 h with pseudo first order rate constants of 5.85 × 10-3 and 8.38 × 10-3 min-1, respectively.

  8. A novel synthetic route for magnesium aluminate (MgAl2O4) nanoparticles using sol-gel auto combustion method and their photocatalytic properties.

    Science.gov (United States)

    Nassar, Mostafa Y; Ahmed, Ibrahim S; Samir, Ihab

    2014-10-15

    In this paper a novel and inexpensive route for the preparation of spinel magnesium aluminate nanoparticles (MgAl2O4) is proposed. Magnesium aluminate photocatalyst was synthesized via sol-gel auto combustion method using oxalic acid, urea, and citric acid fuels at 350°C. Subsequently, the burnt samples were calcined at different temperatures. The pure spinel MgAl2O4 with average crystallite size 27.7, 14.6 and 15.65nm was obtained at 800°C calcinations using the aforementioned fuels, respectively. The obtained samples were characterized by powder X-ray diffraction, Fourier transform infrared, UV-Vis spectroscopy, transmission electron microscope, scanning electron microscope. The photo catalytic activity of MgAl2O4 product was studied by performing the decomposition of Reactive Red Me 4BL dye under UV illumination or sunlight irradiation. The dye considerably photocatalytically degraded by 90.0% and 95.45% under UV and sunlight irradiation, respectively, within ca. 5h with pseudo first order rate constants of 5.85×10(-3) and 8.38×10(-3)min(-1), respectively.

  9. One-pot microwave combustion synthesis of porous Zn(1-x)Cu(x)Al2O4 (0 < or = x < or = 0.5) spinel nanostructures.

    Science.gov (United States)

    Anand, G Theophil; Kennedy, L John

    2013-04-01

    Porous Zn(1-x)Cu(x)Al2O4 (x = 0, 0.1,0.2, 0.3, 0.4, 0.5) spinel nanostructures were synthesized by one-pot microwave combustion technique. All the samples were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and scanning electron microscopy (SEM). The XRD patterns confirm the formation of single phase ZnAl2O4 without any impurities. The results of XRD indicated the average crystallite size in the range of 12.44-22.86 nm. FT-IR spectra show the vibrational stretching frequencies corresponding to the zinc aluminate spinel structure. The estimated band gap of undoped ZnAl2O4 was 4.96 eV indicating the quantum confinement phenomenon. DRS spectra also indicated the band gap narrowing effect with increase in copper ion concentrations. The defect centers acting as trap levels were obtained from photoluminescence studies responsible for the emission spectra. SEM images showed the features of well created pore structures in all the matrices. The percentage porosity of zinc aluminate matrices decreased with increasing copper doping.

  10. La biotecnología aplicada al medio ambiente

    OpenAIRE

    Pueyo, José J.

    2002-01-01

    La Federación Europea de Biotecnología define biotecnología como el uso integrado de la bioquímica, la microbiología, y la ingenieria para la consecución de aplicaciones de las capacidades de microorganismos, células cultivadas animales o vegetales.

  11. Las TICs aplicadas al nivel universitario: compartiendo experiencias

    OpenAIRE

    Paur, Alicia Beatriz; Rosanigo, Zulema Beatriz; Bramati, Pedro

    2005-01-01

    La innovación en los ambientes de enseñanza-aprendizaje con la utilización de nuevas Tecnologías de la Información y la Comunicación (TICs) motoriza la investigación, análisis y evaluación de nuevas herramientas que permitan mejorar la formación de los futuros profesionales, para ello se requiere la actualización de los profesores de las diferentes áreas curriculares con la finalidad de incorporar estos elementos a sus actividades docentes. Una de las herramientas consideradas de suma impo...

  12. La inteligencia emocional aplicada al mundo laboral emotional

    OpenAIRE

    Moreno Lucena, ??lvaro

    2013-01-01

    La inteligencia emocional es uno de los aspectos clave para desenvolverse en el mundo laboral y lograr el ??xito en lo personal, acad??mico y profesional, pero estas competencias y habilidades no son innatas, sino que se pueden trabajar y mejorar. En nuestro sistema educativo se est?? insertando en los ??ltimos tiempos la educaci??n emocional de los alumnos que ayude a desarrollar estas caracter??sticas en los estudiantes, pero todav??a no es suficiente ya que sigue demasiado enfocada hacia e...

  13. Realidad aumentada aplicada al patrimonio histórico molinar

    OpenAIRE

    Miguel Castro García; José Ignacio Rojas Sola; Mª del Pilar Carranza Cañadas

    2011-01-01

    The development of computer tools in the last decade is indisputable evidence that is allowing perceive reality more fully through different techniuqes, such as the Augmented Reality (AR). Taking as a starting point Augmented Reality technology, this study seeks to support the implementation of milling heritage knowledge and its application to the recovery of the Windmills of Andalusia (Spain). In this way, ensures that the visitor gets a more pleasant experience when interpreting the remains...

  14. Realidad aumentada aplicada al patrimonio histórico molinar

    Directory of Open Access Journals (Sweden)

    Miguel Castro García

    2011-04-01

    Full Text Available The development of computer tools in the last decade is indisputable evidence that is allowing perceive reality more fully through different techniuqes, such as the Augmented Reality (AR. Taking as a starting point Augmented Reality technology, this study seeks to support the implementation of milling heritage knowledge and its application to the recovery of the Windmills of Andalusia (Spain. In this way, ensures that the visitor gets a more pleasant experience when interpreting the remains and the operation of these windmills' owm pre-industrial archaeology.

  15. Bases de datos espacio temporales aplicadas al control de velocidades

    OpenAIRE

    2010-01-01

    El objetivo principal de este Proyecto de Fin de Carrera es llevar a la práctica las características de una base de datos espacio-temporal, y en particular, de una base de datos con objetos en movimiento dentro de un dominio concreto como es el de los vehículos de transporte dentro de una empresa. Las bases de datos espacio-temporales manejan cambios relacionados con el movimiento y las formas de los objetos a lo largo de su ciclo de vida. En la resolución del problema se han utilizado geo...

  16. Effects of Ca Content on Formation and Photoluminescence Properties of CaAlSiN3:Eu2+ Phosphor by Combustion Synthesis

    Science.gov (United States)

    Chung, Shyan-Lung; Huang, Shu-Chi

    2016-01-01

    Effects of Ca content (in the reactant mixture) on the formation and the photoluminescence properties of CaAlSiN3:Eu2+ phosphor (CASIN) were investigated by a combustion synthesis method. Ca, Al, Si, Eu2O3, NaN3, NH4Cl and Si3N4 powders were used as the starting materials and they were mixed and pressed into a compact which was then wrapped up with an igniting agent (i.e., Mg + Fe3O4). The compact was ignited by electrical heating under a N2 pressure of ≤1.0 MPa. By keeping the molar ratios of Al and Si (including the Si powder and the Si in Si3N4 powder) both at 1.00 and that of Eu2O3 at 0.02, XRD (X-ray diffraction) coupled with TEM-EDS (transmission electron microscope equipped with an energy-dispersive X-ray spectroscope) and SAED (selected area electron diffraction) measurements show that AlN:Eu2+ and Ca-α-SiAlON:Eu2+ are formed as the major phosphor products when the Ca molar ratio (denoted by Y) is equal to 0.25 and AlN:Eu2+ and Ca-α-SiAlON:Eu2+ could not be detected at Y ≥ 0.75 and ≥1.00, respectively. CASIN (i.e., CaAlSiN3:Eu2+) becomes the only phosphor product as Y is increased to 1.00 and higher. The extent of formation of CASIN increases with increasing Y up to 1.50 and begins to decrease as Y is further increased to 1.68. While the excitation wavelength regions are similar at various Y, the emission wavelength regions vary significantly as Y is increased from 0.25 to 1.00 due to different combinations of phosphor phases formed at different Y. The emission intensity of CASIN was found to vary with Y in a similar trend to its extent of formation. The Ca and Eu contents (expressed as molar ratios) in the synthesized products were found to increase roughly with increasing Y but were both lower than the respective Ca and Eu contents in the reactant mixtures. PMID:28773303

  17. Effects of Ca Content on Formation and Photoluminescence Properties of CaAlSiN3:Eu2+ Phosphor by Combustion Synthesis

    Directory of Open Access Journals (Sweden)

    Shyan-Lung Chung

    2016-03-01

    Full Text Available Effects of Ca content (in the reactant mixture on the formation and the photoluminescence properties of CaAlSiN3:Eu2+ phosphor (CASIN were investigated by a combustion synthesis method. Ca, Al, Si, Eu2O3, NaN3, NH4Cl and Si3N4 powders were used as the starting materials and they were mixed and pressed into a compact which was then wrapped up with an igniting agent (i.e., Mg + Fe3O4. The compact was ignited by electrical heating under a N2 pressure of ≤1.0 MPa. By keeping the molar ratios of Al and Si (including the Si powder and the Si in Si3N4 powder both at 1.00 and that of Eu2O3 at 0.02, XRD (X-ray diffraction coupled with TEM-EDS (transmission electron microscope equipped with an energy-dispersive X-ray spectroscope and SAED (selected area electron diffraction measurements show that AlN:Eu2+ and Ca-α-SiAlON:Eu2+ are formed as the major phosphor products when the Ca molar ratio (denoted by Y is equal to 0.25 and AlN:Eu2+ and Ca-α-SiAlON:Eu2+ could not be detected at Y ≥ 0.75 and ≥1.00, respectively. CASIN (i.e., CaAlSiN3:Eu2+ becomes the only phosphor product as Y is increased to 1.00 and higher. The extent of formation of CASIN increases with increasing Y up to 1.50 and begins to decrease as Y is further increased to 1.68. While the excitation wavelength regions are similar at various Y, the emission wavelength regions vary significantly as Y is increased from 0.25 to 1.00 due to different combinations of phosphor phases formed at different Y. The emission intensity of CASIN was found to vary with Y in a similar trend to its extent of formation. The Ca and Eu contents (expressed as molar ratios in the synthesized products were found to increase roughly with increasing Y but were both lower than the respective Ca and Eu contents in the reactant mixtures.

  18. Solution-combustion synthesized aluminium-doped spinel (LiAl(subx)Mn(sub2-x)O(sub4) as a high-performance lithium-ion battery cathode material

    CSIR Research Space (South Africa)

    Kebede, MA

    2015-06-01

    Full Text Available High-performing (LiAl(subx)Mn(sub2-x)O(sub4) (x = 0, 0.125, 0.25, 0.375, and 0.5) spinel cathode materials for lithium-ion battery were developed using a solution combustion method. The as-synthesized cathode materials have spinel cubic structure...

  19. New data for the discussion about combustion, dioxin and health; Nuevas aportaciones al controvertido debate sobre incineracion, dioxinas y salud

    Energy Technology Data Exchange (ETDEWEB)

    Domingo, S. L. [Universidad Rovira i Virgili. Reus. Tarragona (Spain)

    2000-07-01

    Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD) is created unintentionally as a byproduct of human activities such as combustion, paper belaching, and manufacture of chlorine and organochlorine chemicals. Most information concerning human health risks of dioxin is based on highly exposed industrial cohorts with well established high levels of exposure to TCDD. However, information regarding to the health effects from chronic exposure to low levels of dioxin is very scarce. This paper has two main goals. Firstly, to review the most known international affairs related with a massive exposure to dioxin. Secondly, to assess if the pronounced reduction detected in the emissions of dioxins and furans by the MSWI of Tarragona (Spain) would also result in a notable decrease in the levels of dioxins in environmental matrices collected in the vicinity of the MSWI. The current results show that in comparison with the emission sources of dioxins and furans in the same area of the facility, the health risks due to the current emissions of dioxins and furans by the plant would be of small significance for the population living in the neighbour hod. Moreover, we also show that the daily consumption of 200 g/day of semiskimmed milk instead of the same amount of whole milk would be much more relevant to decrease dioxin exposure that the reduction in dioxin emissions resulting from the technical improvements carried out recently in the MSWI. (Author)

  20. Combustion Synthesis and Photoluminescence Properties of Red-Emitting CaAlSiN3:Eu2+ Phosphor for White-LEDs

    Directory of Open Access Journals (Sweden)

    Shyan-Lung Chung

    2014-12-01

    Full Text Available A combustion synthesis method has been developed for synthesis of Eu2+ doped CaAlSiN3 phosphor and its photoluminescence properties were investigated. Ca, Al, Si, and Eu2O3 powders were used as the Ca, Al, Si and Eu sources. The addition of NaN3, NH4Cl and Si3N4 powders was found to increase significantly the product yield. These powders were mixed and pressed into a compact, which was then wrapped up with an igniting agent (i.e., Mg+Fe3O4. The compact was ignited by electrical heating under a N2 pressure of ≤1.0 MPa. Effects of these experimental parameters on the product yield were investigated and a reaction mechanism was proposed. The synthesized CaAlSiN3:Eu2+ phosphor absorbs light in the region of 200–600 nm and shows a broad band emission in the region of 500–800 nm due to the 4f65d1 → 4f7 transition of Eu2+. The sample doped with Eu2+ at the optimized molar ratio of 0.04 is efficiently excited by the blue light (460 nm and generates emission peaking at ~650 nm with peak emission intensity ~106% of a commercially available phosphor, YAG:Ce3+(P46-Y3.The internal quantum efficiency of the synthesized phosphor was measured to be 71%, compared to 69% of the YAG:Ce3+ (P46-Y3.

  1. Combustion Synthesis and Photoluminescence Properties of Red-Emitting CaAlSiN3:Eu2+ Phosphor for White-LEDs

    Science.gov (United States)

    Chung, Shyan-Lung; Huang, Shu-Chi

    2014-01-01

    A combustion synthesis method has been developed for synthesis of Eu2+ doped CaAlSiN3 phosphor and its photoluminescence properties were investigated. Ca, Al, Si, and Eu2O3 powders were used as the Ca, Al, Si and Eu sources. The addition of NaN3, NH4Cl and Si3N4 powders was found to increase significantly the product yield. These powders were mixed and pressed into a compact, which was then wrapped up with an igniting agent (i.e., Mg+Fe3O4). The compact was ignited by electrical heating under a N2 pressure of ≤1.0 MPa. Effects of these experimental parameters on the product yield were investigated and a reaction mechanism was proposed. The synthesized CaAlSiN3:Eu2+ phosphor absorbs light in the region of 200–600 nm and shows a broad band emission in the region of 500–800 nm due to the 4f65d1 → 4f7 transition of Eu2+. The sample doped with Eu2+ at the optimized molar ratio of 0.04 is efficiently excited by the blue light (460 nm) and generates emission peaking at ~650 nm with peak emission intensity ~106% of a commercially available phosphor, YAG:Ce3+(P46-Y3).The internal quantum efficiency of the synthesized phosphor was measured to be 71%, compared to 69% of the YAG:Ce3+ (P46-Y3). PMID:28788278

  2. 微波辅助溶液燃烧法制备 MgAl2 O4粉体%Synthesis of MgAl2 O4 powders by microwave-assisted combustion

    Institute of Scientific and Technical Information of China (English)

    王朔; 余俊; 赵惠忠; 李超; 王斌斌; 段连威

    2014-01-01

    High purity,low agglomeration MgAl2O4 powders were synthesized by the microwave-assisted low temperature combustion method using magnesium nitrate,aluminum nitrate and urea (mass ratio of 1 2 6.66) as starting materials,mixing in water forming a transparent precursor liquid.The effects of the microwave out-put power (200,400,600,and 700 W)on the microstructure,morphology and specific surface area of MgAl2O4 powders were analyzed.The results show that the microwave-assisted combustion method can accelerate combusti on reacti on to produce l arge vol umes of gas i nstantl y,formi ng ul tra-fi ne MgAl 2 O4 parti cl es.Moreo-ver,the increasing microwave output power accelerates the oxidation of urea,which is beneficial to the growth of MgAl2O4 grains.Under the conditions of microwave power 700 W for 2 min,the high crystallinity MgAl 2 O4 powder wi th a uni form parti cl e si ze di stri buti on (average grai n si ze of 56.03 nm)can be prepared.%将硝酸镁、硝酸铝、尿素按物质的量比为126.66制得透明混合前驱液,用低温燃烧技术与微波加热技术相结合的方法制备了高纯度、低团聚的镁铝尖晶石(MgAl2 O4)粉体。研究了燃烧反应过程中,微波输出功率(200、400、600、700 W)对MgAl2 O4粉体晶体结构、形貌及比表面积的影响。结果表明:微波高效加热方式导致燃烧反应瞬间产生大量气体,促进了MgAl2 O4超细颗粒的形成。同时,随着微波输出功率的增加,尿素氧化加速,利于MgAl2 O4晶粒的生长发育。在微波功率700 W,微波时间2 min的条件下,可制备结晶完整,粒度分布均匀(平均晶粒尺寸为56.03 nm)的MgAl2O4粉体。

  3. AlSi17Cu5Mg alloy as future material for castings of pistons for internal combustion engines

    Directory of Open Access Journals (Sweden)

    J. Piątkowski

    2015-07-01

    Full Text Available The paper presents chosen properties and microstructure of AlSi17Cu5Mg alloy as future material for casting pistons in automotive industry. Tests were conducted to elaborate technology of preparation, assessment of crystallisation parameters and shaping the primary structure of the silumin with the aim to improve the working parameters and the functioning efficiency in cylinder-piston system. Refinement of Si crystals, achieved due to overheating above the temperature Tliq. causes that the alloy reaches satisfactory properties in working chamber of the engine are optimised. Such condition of material characteristics causes that hypereutectic silumins, for chosen applications in transport, may serve as an alternative to Al - Si alloys of hypoeutectic and near - eutectic type.

  4. Calotropis procera mediated combustion synthesis of ZnAl2O4:Cr3+ nanophosphors: Structural and luminescence studies

    Science.gov (United States)

    Ravikumar, B. S.; Nagabhushana, H.; Sharma, S. C.; Vidya, Y. S.; Anantharaju, K. S.

    2015-02-01

    ZnAl2O4:Cr3+ nanophosphors were synthesized for the first time by a simple and environment friendly route using Calotropis procera milk latex as fuel. The structural and surface morphological studies were carried out using powder X-ray diffraction (PXRD), scanning electron microscopy and transmission electron microscopy techniques. The photoluminescence (PL) properties of ZnAl2O4:Cr3+ as a function of dopant concentration and calcination temperature was studied in detail. The PXRD patterns and Rietveld confinement confirmed the cubic crystal system with space group Fd-3m. The crystallite size estimated from Scherrer's and W-H plots was found to be in the range of 16-26 nm. The PL spectrum shows an intense peak at ∼688 and ∼699 nm assigned to spin - forbidden 2Eg → 4A2g transition of Cr3+ ions. The PL measurements for two excitations (∼410 and 527 nm) and with respect to calcination temperature indicated no significant change in the shape and position of emission peak except PL intensity. The CIE chromaticity coordinates lies well within the white region. Thermoluminescence (TL) studies revealed well resolved glow peak at ∼212 °C with a small shoulder at 188 and 233 °C. The glow peak intensity at ∼212 °C increases linearly with γ-dose which suggest ZnAl2O4:Cr3+ is suitable candidate for radiation dosimetric applications. The activation energy (E in eV), order of kinetics (b) and Frequency factor (s) were estimated using glow peak shape method.

  5. Calotropis procera mediated combustion synthesis of ZnAl2O4:Cr(3+) nanophosphors: structural and luminescence studies.

    Science.gov (United States)

    Ravikumar, B S; Nagabhushana, H; Sharma, S C; Vidya, Y S; Anantharaju, K S

    2015-02-05

    ZnAl2O4:Cr(3+) nanophosphors were synthesized for the first time by a simple and environment friendly route using Calotropis procera milk latex as fuel. The structural and surface morphological studies were carried out using powder X-ray diffraction (PXRD), scanning electron microscopy and transmission electron microscopy techniques. The photoluminescence (PL) properties of ZnAl2O4:Cr(3+) as a function of dopant concentration and calcination temperature was studied in detail. The PXRD patterns and Rietveld confinement confirmed the cubic crystal system with space group Fd-3m. The crystallite size estimated from Scherrer's and W-H plots was found to be in the range of 16-26 nm. The PL spectrum shows an intense peak at ∼688 and ∼699 nm assigned to spin-forbidden (2)Eg→(4)A2g transition of Cr(3+) ions. The PL measurements for two excitations (∼410 and 527 nm) and with respect to calcination temperature indicated no significant change in the shape and position of emission peak except PL intensity. The CIE chromaticity coordinates lies well within the white region. Thermoluminescence (TL) studies revealed well resolved glow peak at ∼212°C with a small shoulder at 188 and 233°C. The glow peak intensity at ∼212°C increases linearly with γ-dose which suggest ZnAl2O4:Cr(3+) is suitable candidate for radiation dosimetric applications. The activation energy (E in eV), order of kinetics (b) and Frequency factor (s) were estimated using glow peak shape method.

  6. NH4Cl对机械活化Al粉燃烧合成AlN的控制%Effects of NH4CI on the synthesis of aluminum nitride by the spontaneous combustion of mechanically activated aluminium powder

    Institute of Scientific and Technical Information of China (English)

    刘建平; 张晖

    2011-01-01

    添加NH4Cl到经由高能球磨制得的机械活化铝粉中后,铝粉在空气中于室温下即可发生自燃反应.本研究通过含有不同量NH4Cl的机械活化铝粉的自燃制得了Al2O3-AlN疏松粉末,并研究了NH4CL添加量对燃烧产物成分和结构的控制.结果表明:NH4Cl不仅控制了产物的形貌,而且改变了铝粉的氮化初理.在NH4Cl添加量为3%~5%(质量分数)时,所得燃烧产物颗粒大小相对较均匀,并含有700%(质量分数)以上的AlN.%With the addition of NH4CI, the mechanically activated aluminum powder made by high energy ball milling could bum spontaneously in air at room temperature with the formation of Al2O3-AIN powder. In this study, AIN powders were prepared by the spontaneous combustion of aluminum powder including different amounts of NH4CI. The effects of NH4Cl content on the composition and structure of the combustion product were studied by characterizing the phase and morphology of combustion products. The results show that NH4CI not only affects the morphology of products, but also changes the nitridation mechanism of aluminum powder. When 3%~5% (mass fraction) NH4CI is added, the sizes of particles included in the combustion product show small variation and the content of AIN in the combustion product is above 70% (mass fraction).

  7. Bonding characteristics of the Al2O3-metal composite coating fabricated onto carbon steel by combustion synthesis

    Institute of Scientific and Technical Information of China (English)

    Xiao-feng Xue; Ze-hua Wang; Ze-hua Zhou; Shao-qun Jiang; Jiang-bo Cheng; Chang-hao Wang; Jia Shao

    2014-01-01

    The fabrication of an alumina-metal composite coating onto a carbon steel substrate by using a self-propagating high-temperature synthesis technique was demonstrated. The effects of the type and thickness of the pre-coated layer on the binding structure and surface qual-ity of the coating were systematically investigated. The macrostructure, phase composition, and bonding interface between the coating and the substrate were investigated by scanning electronic microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectrome-try (EDS). The diffraction patterns indicated that the coating essentially consisted ofα-Al2O3, Fe(Cr), and FeO⋅Al2O3. With an increase in the thickness of the pre-coated working layer, the coating became more smooth and compact. The transition layer played an important role in enhancing the binding between the coating and the substrate. When the pre-coated working layer was 10 mm and the pre-coated transition layer was 1 mm, a compact structure and metallurgical bonding with the substrate were obtained. Thermal shock test results indicated that the ceramic coating exhibited good thermal shock resistance when the sample was rapidly quenched from 800°C to room temperature by plung-ing into water.

  8. Solar energy as fuel to move the world; La energia solar como combustible para mover al mundo

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Arturo; Gamboa, Sergio [Centro de Investigacion en Energia (CIE) de la UNAM, Temixco, Morelos (Mexico)

    2010-07-01

    Among the technologies that can be used to take properly advantage of the Sun, we have the development of various solar devices, ranging from the solar collectors, equipment that convert the solar radiation into heat, until the solar cells that convert sunlight into electricity. The development and implementation of these devices in various countries of the world, has allowed us to evaluate the technical feasibility of the technologies associated with the development and use of Renewable Energies to solve the global energy problems, and, in this way, achieve the long-awaited energy independence to which aspire all the nations of the planet. [Spanish] Entre las tecnologias que se pueden utilizar para aprovechar de forma adecuada al Sol, tenemos el desarrollo de diversos dispositivos solares, los cuales van desde los captadores solares, equipos que convierten la radiacion solar en calor, hasta las celdas solares, que convierten la luz del Sol en electricidad. El desarrollo e implementacion de estos dispositivos en diversos paises del mundo, han permitido evaluar la factibilidad tecnica de las tecnologias asociadas al aprovechamiento y uso de las Energias Renovables para resolver los problemas energeticos globales, y, de esta forma, conseguir la tan ansiada independencia energetica a la que aspiran todas las naciones del planeta.

  9. Combustion synthesized copper-ion substituted FeAl2O4 (Cu0.1Fe0.9Al2O4): A superior catalyst for methanol steam reforming compared to its impregnated analogue

    Science.gov (United States)

    Maiti, Sayantani; Llorca, Jordi; Dominguez, Montserrat; Colussi, Sara; Trovarelli, Alessandro; Priolkar, Kaustubh R.; Aquilanti, Giuliana; Gayen, Arup

    2016-02-01

    A series of copper ion substituted MAl2O4 (M = Mg, Mn, Fe and Zn) spinels is prepared by a single step solution combustion synthesis (SCS) and tested for methanol steam reforming (MSR). The copper ion substituted Cu0.1Fe0.9Al2O4 appears to be the most active, showing ∼98% methanol conversion at 300 °C with ∼5% CO selectivity at GHSV = 30,000 h-1 and H2O:CH3OH = 1.1. The analogous impregnated catalyst, CuO (10 at%)/FeAl2O4, is found to be much less active. These materials are characterized by XRD, H2-TPR, BET, HRTEM, XPS and XANES analyses. Spinel phase formation is highly facilitated upon Cu-ion substitution and Cu loading beyond 10 at% leads to the formation of CuO as an additional phase. The ionic substitution of copper in FeAl2O4 leads to the highly crystalline SCS catalyst containing Cu2+ ion sites that are shown to be more active than the dispersed CuO nano-crystallites on the FeAl2O4 impregnated catalyst, despite its lower surface area. The as prepared SCS catalyst contains also a portion of copper as Cu1+ that increases when subjected to reforming atmosphere. The MSR activity of the SCS catalyst decreases with time-on-stream due to the sintering of catalyst crystallites as established from XPS and HRTEM analyses.

  10. Estrategias de financiamiento aplicadas por hipermercados en un entorno competitivo

    Directory of Open Access Journals (Sweden)

    Miraidy Leal Morantes

    2003-01-01

    Full Text Available El presente estudio tiene como objetivo analizar las estrategias de financiamiento aplicadas en el sector de la distribución de bienes de consumo masivo, tomando como referencia la experiencia de los hipermercados ubicados en Maracaibo, Estado Zulia. Se desarrolló una investigación de carácter descriptivo; para la recolección de datos se aplicó un cuestionario estructurado a gerentes generales y financieros, así como entrevistas no estructuradas a personal administrativo clave de las organizaciones. Los resultados evidencian que las estrategias de financiamiento utilizadas son la integración vertical en redes de proveedores, el endeudamiento bancario y la reinversión de utilidades, como manera de responder al nuevo escenario que plantea la economía mundial. Se concluye que la creciente penetración de las grandes cadenas en el país produce efectos que inciden directamente en proveedores, consumidores y empresas venezolanas del sector.

  11. 镁/铝合金水反应金属燃料推进剂的燃烧性能%Combustion Performances of Mg-Al Alloy Hydro-reactive Metal Fuel Propellant

    Institute of Scientific and Technical Information of China (English)

    高明; 郭晓燕; 邹美帅; 杨荣杰

    2015-01-01

    通过高能球磨工艺制备了高活性球磨镁/铝合金粉,并制备了两组镁/铝基水反应金属燃料推进剂,用固体推进剂燃速测试系统测定了其燃速。采用氧弹量热仪测定了推进剂的爆热值,并收集推进剂的一次燃烧固相产物,将其放置于水蒸汽高温管式炉中模拟二次燃烧。采用 SEM、XRD 及化学分析方法表征了水反应金属燃料的一、二次燃烧固相产物。结果表明,高活性球磨镁/铝合金水反应金属燃料推进剂具有更高的燃速和爆热值;二次燃烧产物剩余铝含量更低,二次燃烧产物反应更彻底;高活性球磨镁/铝合金能够改善其水反应金属燃料推进剂的一次燃烧效果,可提高其在二次燃烧中铝的燃烧效率。%High active ball-milling Mg-Al alloy powders were prepared by a high-energy ball-milling process from Mg-Al alloy.Two groups of Mg-Al based hydro-reactive metal fuel propellants were prepared.The burning rate of the propellant was measured by a burning rate measuring system of solid propellants.The value of heat of explosion of the propellant was measured by an oxygen bomb calorimeter and the solid products of primary combustion were collected.The secondary combustion of the solid products of primary combustion was simulated in the water vapor high temperature tube furnace.The solid products of primary combustion and secondary combustion of hydro-reac-tive metal fuel propellants were characterized by SEM,XRD and chemical analysis method.Results show that high active ball-milling Mg-Al alloy hydro-reactive metal fuel propellants have higher burning rate and heat of explosion. The residual Al content in secondary combustion products is lower and the reaction of secondary combustion product is more thorough.High active ball-milling Mg-Al alloy can improve the primary combustion effect of hydro-reactive metal fuel propellants and the combustion efficiency of Al in secondary combustion.

  12. Ciencia básica y ciencia aplicada

    Directory of Open Access Journals (Sweden)

    Pérez-Tamayo Ruy

    2001-01-01

    Full Text Available En el contexto de una intervención en el Foro de Consulta Democrática de la Coordinación de los Institutos Nacionales de Salud sobre Enseñanza e Investigación en Salud, realizado en el Instituto Nacional de Cardiología Ignacio Chávez, se hace una revisión crítica de la clasificación convencional de la ciencia en básica y aplicada; además, se analiza lo que deberían ser la enseñanza y la investigación en salud. Para apoyar su propia clasificación de la ciencia en "bien hecha", la cual "genera conocimientos verificables sobre la realidad" y la "mal hecha", improductiva o productora de "puras mentiras" y "no debe patrocinarse", el autor revisa las definiciones utilitaristas y peyorativas como las que establecen ciencia comprometida y ciencia pura, ciencia útil y ciencia inútil, y ciencia práctica y ciencia esotérica, como sinónimos de ciencia aplicada y ciencia básica y afirma que, en México, esta diferenciación "para lo único que ha servido en el pasado es para justificar la reducción en el apoyo oficial a la ciencia básica, porque no estaba dirigida a resolver ´los problemas nacionales´o porque no caía en las prioridades establecidas en ese sexenio". En cuanto a educación e investigación en salud reconoce que el programa actual de formación de investigadores tiene una eficiencia muy baja y propone un estudio científico crítico, realizado por un equipo de especialistas, interdisciplinario, "para integrar la carrera del investigador científico desde la captura de la juventud inteligente hasta la jubilación o muerte del investigador" y para el cual la evaluación de la eficiencia del apoyo a sus proyectos de investigación no se restrinja a si se publicó o no un artículo "pues la calidad del trabajo científico y la contribución de un investigador al desarrollo de la ciencia no es nada más el número de sus publicaciones". El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

  13. Sistema experto de ergonomía aplicada

    Directory of Open Access Journals (Sweden)

    Jesús Mora Ruiz

    2004-01-01

    Full Text Available Son muchos los países que están utilizando las modernas tecnologías de la información aplicadas a la educación. Este fenómeno es parte de la nueva revolución industrial o era de la información que está afectando a casi todas las actividades humanas. La investigación, diseño e implementación de tecnologías que suplan las carencias de recursos económicos para la adquisición de laboratorios que cuenten con todo lo necesario para la realización de prácticas que reafirmen lo teórico. En el desarrollo del proceso de enseñanza-aprendizaje, debe tenerse en cuenta un modelo pedagógico, donde participen activamente tanto el catedrático como los estudiantes. El desarrollo de Sistemas Expertos, basados en Inteligencia Artificial, para realizar prácticas aplicadas a la Ingeniería Industrial, ofrece una posibilidad diferente de modelo educativo, con la que el alumno reafirmará una y otra vez la práctica, en la que aplicará los conocimientos teóricos adquiridos en las aulas; lo que dará un valor agregado a su profesión, para lograr un mejor desempeño en aplicaciones en áreas de la Ingeniería Industrial. Los Sistemas Expertos basados en la Inteligencia Artificial utilizados como emuladores basados en el conocimiento, diseñados y desarrollados por las propias instituciones con recursos propios, son una solución factible y económica, que resuelven las necesidades fundamentales en el proceso de enseñanza- aprendizaje; ya que con ellos se efectúan prácticas de diseños ergonómicos, al mismo tiempo que dan respuestas expertas para la aplicación de la materia de Ergonomía; factor imprescindible en la formación del Ingeniero Industrial

  14. Effect of Nano-Nickel Powder on Combustion Properties of Al-CMDB and CL-20-CMDB Propellants%纳米镍粉对Al-CMDB和CL-20-CMDB推进剂燃烧性能的影响

    Institute of Scientific and Technical Information of China (English)

    袁志锋; 赵凤起; 张教强; 宋秀铎; 高红旭; 郑伟; 王瑛; 裴江峰; 王晶

    2016-01-01

    To investigate the effect of nano-nickel powder with particle size of 50nm on the combustion properties of Al-CMDB and CL-20-CMDB propellants, the propellant samples were prepared through the rolling-absorption method. The burning rates of the propellants were measured by the target line method and the pressure exponents were calculated. The reason of how nano-nickel powder affect the combustion properties of Al-CMDB propellant was studied by flame photo, burning wave, DSC, morphology and elemental analysis of flameout surface. The results show that in Al-CMDB propellant, adding nano-nickel powder can greatly improve the burning rate and reduce the pressure exponent of the propellant. The burning rate of the propellant at 10MPa reaches 35.59mm/s, the pressure exponent between 8-20MPa reduces from 0.43 to 0.17, and the propellant appears mesa effect between 15-20MPa when adding 0.7% (mass fraction)nano-nickel powder into the Al-CMDB propellant. In CL-20-CMDB, adding 0.5%(mass fraction)nano-nickel powder to CL-20-CMDB propellant can increase the burning rate of the propellant greatly at 4-10MPa,the pressure exponent between 8-20MPa is about 0.01 and the propellant appears mesa effect between 15-20MPa.%为了研究粒径为50nm的纳米镍粉(nano-Ni)对含Al改性双基(Al-CMDB)推进剂、含六硝基六氮杂异伍兹烷(CL-20)改性双基(CL-20-CMDB)推进剂燃烧性能的影响,通过吸收-压延的方法制备了推进剂样品,用靶线法测试了推进剂的燃速,并计算了压强指数.通过电镜扫描、火焰照片、燃烧波、熄火表面形貌及元素分析和DSC分析了纳米镍粉对Al-CMDB推进剂燃烧性能影响的原因.结果表明,在Al-CMDB推进剂中加入nano-Ni可大幅度提高推进剂燃速,降低推进剂的压强指数;当加入质量分数0.7%的nano-Ni时推进剂10MPa的燃速达到35.59mm/s,8~20MPa压强指数从0.43降低至0.17,15~20MPa出现麦撒效应.在CL-20-CMDB推进剂中加入质量分数0.5%的nano-Ni能明

  15. Optical and EPR Spectroscopic Studies of Deep Red Light Emitting Fe-Doped LiAl5O8 Phosphor Prepared Via Propellant Combustion Route

    Science.gov (United States)

    Singh, Vijay; Sivaramaiah, G.; Rao, J. L.; Singh, N.; Mohapatra, M.; Singh, P. K.; Pathak, M. S.; Dhoble, S. J.

    2016-12-01

    LiAl5O8 doped with Fe was synthesized by a propellant combustion route at furnace temperature of 773 K. The phosphor was characterized using powder x-ray diffraction, optical absorption, electron paramagnetic resonance (EPR) and photoluminescence spectroscopic techniques. The optical absorption spectrum exhibits a broad band at 242 nm characteristic of charge transfer between Fe3+-O2-. On excitation with 293 nm, emission band for the Fe3+ ion was observed at 687 nm. The CIE (International Commission on Illumination or Commission Internationale de l'Elcairage) coordinates for the system were evaluated adopting standard procedure which suggested that the system can be effective as a deep red emitting phosphor. The EPR spectrum of this phosphor exhibits a number of resonance signals characteristic of Fe3+ ions. The resonance signals at g = 3.16, 2.27 are attributed to Fe3+ present at tetrahedral site with an axial symmetry. The resonance signals at g = 1.98 and 1.43 are attributed to Fe3+ ions in octahedral site with an axial symmetry. Various EPR parameters such as the number of spins, Gibbs free energy, magnetic susceptibility, Curie constant and effective magnetic moment values are calculated and compared at room temperature and 110 K.

  16. PNI 对 RDX/Al-CMDB 推进剂燃烧性能的影响%Effect of PNI on the Combustion Properties of RDX/Al-CMDB Propellant

    Institute of Scientific and Technical Information of China (English)

    袁志锋; 赵凤起; 杨立波; 郑晓东; 张超; 田军

    2014-01-01

    The RDX/Al-CMDB propellants containing 4-initroimidazole lead salt (PNI)were prepared by an absorp-tion/rolling method.The burning rates of propellants were measured by a target line method.The effect of PNI/carbon,PNI/carbon/stabilizer,PNI/Pb salts on the combustion properties of RDX/Al-CMDB propellants were studied.The results show that PNI is an effective energetic burning catalyst.The combination of PNI with carbon black orβ-Pb salt makes the mesa effect or plateau of CMDB propellant appear.When the mass fraction of PNI is 4. 0%,it makes the pressure exponent of propellant decrease to 0.07.The combination of 1 .0% PNI and 2.5% β-Pb salt makes the pressure exponent of propellant decrease to -0.13.The burning rate of RDX/Al-CMDB propellants containing PNI is adjustable and can appear the plateau or mesa effect.%采用吸收-压延方法制备了含4-硝基咪唑铅盐(PNI)的 RDX/Al-CMDB 推进剂样品,用靶线法测试了其燃速,研究了 PNI 与炭黑组成的二组元催化剂,PNI、炭黑和安定剂组成的三组元催化剂,PNI 与不同种类铅盐组成的多组元催化剂对 RDX/Al-CMDB 推进剂燃烧性能的影响。结果表明,PNI 是一种有效的含能燃烧催化剂;PNI 与炭黑或β铅盐的混合物可使推进剂出现平台或麦撒燃烧;当 PNI 的质量分数为4.0%时,推进剂的压强指数降至0.07;1.0%PNI 和2.5%β-Pb 的混合物使推进剂的压强指数降至-0.13。含 PNI 改性双基推进剂的燃速可调,出现平台或麦撒区间。

  17. Econometría básica aplicada con Gretl

    OpenAIRE

    Esteban González, María Victoria; Moral Zuazo, María Paz; Orbe Mandaluniz, Susan; Regúlez Castillo, Marta; Zárraga Alonso, Ainhoa; Zubia Zubiaurre, Marian

    2009-01-01

    Estas notas de clase son de utilidad como material docente, sirviendo de apoyo o complemento, para aquellos alumnos que bien vayan a hacer o hayan seguido alguna asignatura como Introducción a la Econometría (en LE o LADE), Estadística Actuarial: Regresión (LCAF), Econometría aplicada al mercado (LITM). También puede estar indicada para alumnos de las licenciaturas ofrecidas en la Facultad de Ciencias Sociales y de la Comunicación, por ejemplo la Licenciatura de Publicidad y RR.PP. y de algun...

  18. Tululite, Ca14(Fe3+,Al)(Al,Zn,Fe3+,Si,P,Mn,Mg)15O36: a new Ca zincate-aluminate from combustion metamorphic marbles, central Jordan

    Science.gov (United States)

    Khoury, Hani N.; Sokol, Ella V.; Kokh, Svetlana N.; Seryotkin, Yurii V.; Nigmatulina, Elena N.; Goryainov, Sergei V.; Belogub, Elena V.; Clark, Ian D.

    2016-02-01

    Tululite (Ca14(Fe3+,Al)(Al,Zn,Fe3+,Si,P,Mn,Mg)15O36 (the hypothetical end-member formula Ca14{Fe3+O6}[SiO4][Zn5Al9]O26) (IMA2014-065) is a new natural Ca zincate-aluminate, identified in medium-temperature (800-850 °C) combustion metamorphic (CM) spurrite-fluorellestadite marbles from central Jordan. The type locality (Tulul Al Hammam area) is situated in the northern part of the Siwaqa complex, the largest area of the "Mottled Zone" Formation in the Dead Sea region. The marbles originated from bitumen-rich chalky marine sediments of the Maastrichtian-Paleogene Muwaqqar Chalk Marl Formation, which have low clay content (and, consequently, low Al) and high Zn, Cd, and U enrichments. The bulk CM rocks derived from the low-Al protolith have unusually high (Zn + Cd)/Al ratios ( 0.2) and, as a result, a mineralogy with negligibly small percentages of Ca aluminates having low Ca:Al molar ratios (minerals of mayenite supergroup, Ca:Al = 6:7) common to most of calcareous CM rocks in the Mottled Zone. Instead, the mineral assemblage of the Zn-rich marbles contains tululite, with high Ca:Al = 2.55 molar ratios and Zn substituting for a large portion of Al (Zn:Al = 1.1). Tululite occurs in thin clusters as irregular grains with indented outlines (20-100 μm in size), having typical open-work textures associated with rock-forming calcite, fluorellestadite, spurrite, and accessory Zn-rich periclase, lime-monteponite solid solutions, calcium uranates, and zincite. Marbles also bear brownmillerite, dorrite, fluormayenite, high-fluorine Ca aluminate, and lakargiite. Secondary phases are brucite, gel-like calcium silicate hydrates and calcium silicate aluminate hydrates, including Zn- and U-bearing and Cd-rich compounds, Si-bearing hydrated compounds after calcium uranates, and basic Cd chlorides. The empirical formula of the holotype tululite (a mean of 32 analyses) is (Ca13.29Cd0.75)Σ14.04(Al5.46Zn5.20Fe3+ 2.23Si0.95Mn3+ 1.01Mg0.78P0.41)Σ16.04O36. Tululite is cubic, space

  19. Computational Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C K; Mizobuchi, Y; Poinsot, T J; Smith, P J; Warnatz, J

    2004-08-26

    Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

  20. SIMULACIÓN DE UN ESCURRIMIENTO REACTIVO AL INTERIOR DE UNA CÁMARA DE COMBUSTIÓN REACTIVE FLUID FLOW SIMULATION INSIDE COMBUSTION CHAMBER

    Directory of Open Access Journals (Sweden)

    Carlos H Salinas Lira

    2007-04-01

    Full Text Available El presente trabajo dice relación con la simulación de gases calientes al interior de una cámara de tubular combustión. Siendo así, se generan mallas en dominios tubulares curvilíneos. La inyección de combustible es realizada a través de un cuerpo esférico posicionado en el eje de simetría de la cámara afectado por un flujo primario axial y un flujo secundario radial. El fluido es considerado Newtoniano incompresible y con propiedades termo físicas constantes, en cuanto el flujo es considerado laminar, modelado a través de la ecuaciones de Navier-Stokes. La formulación de Shvab-Zel'dovich es utilizada para modelar el transporte de energía y especies a través de una variable denominada Potencial de Acoplamiento. El modelo matemático es resuelto numéricamente a través del Método de los Volúmenes Finitos descrito en coordenadas curvilíneas con arreglo co-localizado de variables. Los términos difusivos son representados por diferencias centradas y se usa el esquema WUDS para los términos convectivos. La integración temporal es del tipo implícito. Resultados de campos de velocidades, temperaturas y concentraciones son mostrados y comparados con datos encontrados en la literatura especializada. Se concluye en cuanto a la calidad cualitativa y cuantitativa de los resultados generados y en particular en lo que dice relación con la forma de la llama.The present work is related to the simulation of hot gases inside a tubular combustion chamber. This way, meshes are generated in tubular curvilinear domains. The fuel injection is carried out through a spherical body positioned in the chamber symmetry axis, affected by an axial primary flow and a radial secondary flow. The fluid is considered Newtonian incompressible, with constant thermo physics properties. In regard to the fluid flow, this is considered laminar, modeled through Navier-Stokes Equations. The Shvab-Zel'dovich formulation is used to model energy and species transport

  1. Effect of the container in the synthesis of the combustion reaction of ZnAl{sub 2}O{sub 4}; Efeito do tipo de reciente na sintese por reacao de combustao do ZnAl{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Silva, D.A.R.; Cavalcanti, L.R.C.; Moura, A.L.S.; Rocha, M.L.; Neto, O.L.A.; Cabral, I.C.; Viana, K.M.S., E-mail: kalineviana@ect.ufrn.br [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Costa, A.C.F.M. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2012-07-01

    In the present work is a study on the influence of the container in the synthesis of the combustion reaction ZnAl{sub 2}O{sub 4}. Products of combustion obtained for both synthesis routes, were broken and sieved in 325 mesh (44μm). The powders resulting from two types of synthesis were characterized by X-ray diffraction and scanning electron microscopy. By means of XRD analysis showed the formation of the main phase of zinc aluminate spinel (Z) as phase the mineral guanine in the two procedures synthesis. By means of SEM analysis showed that in the procedure used the crucible metal zinc aluminate is introduced in the form of smaller agglomerates. Therefore, the container used in the synthesis of combustion influences the microstructure of the material synthesized. (author)

  2. Lingüística aplicada e o ensino de línguas estrangeiras no Brasil

    Directory of Open Access Journals (Sweden)

    John Robert Schmitz

    2001-02-01

    Full Text Available

    Procura-se neste trabalho apresentar um esboço de Lingüística Aplicada e o Ensino de Línguas Estrangeiras no mundo e também no Brasil. Conclui-se que a disciplina está em pleno desenvolvimento com contribuições pertinentes para o ensino e aprendizagem de línguas, além de outras áreas de conhecimento tais como língua pátria, ensino bilíngüe, tradução, alfabetização e letramento. Destaca-se no artigo o estado da arte em Lingüística Aplicada no Brasil que atinge no momento, especialmente no campo de ensino de línguas estrangeiras, a sua maturidade após vinte anos de atividade.

  3. 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.

  4. MnOx/Al2O3/Ce0.45Zr0.45M0.10Oy (M = Mn,Y,La) catalysts used for ethanol catalytic combustion

    Institute of Scientific and Technical Information of China (English)

    Hongyan Cao; Weicong Song; Maochu Gong; Jianli Wang; Shenghui Yan; Zhimin Liu; Yaoqiang Chen

    2009-01-01

    MnOx/Al2O3/Ce0.45Zr0.45M0.10Oy (M = Mn,Y,La) catalysts were prepared by impregnation method and characterized by BET,TPR and XRD analyses.The catalytic activities toward ethanol combustion were investigated in a microreactor.The results demonstrated that the catalytic activity of MnOx/Al2O3/Ce0.50Zr0.50O2 monolithic catalyst could be improved by doping Mn,Y and La into Ce0.50Zr0.50O2.When doping Y into Ce0.50Zr0.50O2,the catalyst MnOx/Al2O3/Ce0.45Zr0.45Y0.10O1.95 showed the highest activity.The 100% conversion temperature of ethanol was 230 ℃.Furthermore,once the conversion of ethanol started,the complete conversion was quickly achieved.The doping of Mn,Y and La led to better activity for ethanol combustion and lower temperature reduction peaks in TPR profiles.The doping of Mn resulted in enhanced oxygen storage capacity (OSC),larger area of the reduction peaks,and excellent reactivity,and the doping of Y resulted in the lowest reduction temperature and the best activity.

  5. 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.

  6. Applied combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    From the title, the reader is led to expect a broad practical treatise on combustion and combustion devices. Remarkably, for a book of modest dimension, the author is able to deliver. The text is organized into 12 Chapters, broadly treating three major areas: combustion fundamentals -- introduction (Ch. 1), thermodynamics (Ch. 2), fluid mechanics (Ch. 7), and kinetics (Ch. 8); fuels -- coal, municipal solid waste, and other solid fuels (Ch. 4), liquid (Ch. 5) and gaseous (Ch. 6) fuels; and combustion devices -- fuel cells (Ch. 3), boilers (Ch. 4), Otto (Ch. 10), diesel (Ch. 11), and Wankel (Ch. 10) engines and gas turbines (Ch. 12). Although each topic could warrant a complete text on its own, the author addresses each of these major themes with reasonable thoroughness. Also, the book is well documented with a bibliography, references, a good index, and many helpful tables and appendices. In short, Applied Combustion does admirably fulfill the author`s goal for a wide engineering science introduction to the general subject of combustion.

  7. Microwave combustion synthesis, structural, optical and magnetic properties of Zn{sub 1−x}Co{sub x}Al{sub 2}O{sub 4} (0 ⩽ x ⩽ 0.5) spinel nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Anand, G. Theophil [Materials Division, School of Advanced Sciences, Vellore Institute of Technology (VIT) University, Chennai Campus, Chennai 600 127, Tamil Nadu (India); Department of Physics and Abraham Panampara Research Center (APRC), Sacred Heart College (Autonomous), Tirupattur 635 601, Tamil Nadu (India); Kennedy, L. John, E-mail: jklsac14@yahoo.co.in [Materials Division, School of Advanced Sciences, Vellore Institute of Technology (VIT) University, Chennai Campus, Chennai 600 127, Tamil Nadu (India); Vijaya, J. Judith [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College (Autonomous), Chennai 600 034, Tamil Nadu (India)

    2013-12-25

    Highlights: •Co doped ZnAl{sub 2}O{sub 4} nanostructures were synthesized by microwave combustion method. •The XRD patterns confirm the formation of single phase ZnAl{sub 2}O{sub 4} without impurities. •The direct band gap decreased with increasing Co{sup 2+} content from 5.01 to 2.89 eV. •Magnetic measurements revealed Co doped ZnAl{sub 2}O{sub 4} has superparamagnetic behavior. -- Abstract: Cobalt doped zinc aluminate spinel type nanostructures were synthesized by microwave combustion method. The structural, vibrational, optical, morphological and magnetic properties were studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray diffraction (EDX) and vibrating sample magnetometry (VSM) respectively. The XRD patterns confirmed the formation of single phase ZnAl{sub 2}O{sub 4} cubic spinel without impurities. The lattice parameter increased from 8.081 to 8.116 Å with increasing Co{sup 2+} content. The average crystallite size of the nanoparticles estimated using Debey–Scherrer’s method was found to be in the range of 11.80–20.21 nm. The presence of tensile strain in the zinc aluminates was determined from Williamson–Hall (W–H) analysis. FT-IR spectra showed the vibrational stretching frequencies corresponding to the zinc aluminate spinel structure. The direct band gap estimated using Kubelka–Munk method decreased with increasing Co{sup 2+} content (5.01–2.89 eV), due to the formation of sub bands in between the energy gap. Optical absorption spectra confirmed the cobalt substitution by the occurrence of a triplet of bands at 542, 584, and 624 nm, which is the characteristic of Co{sup 2+} ions in the tetrahedral sites. For ZnAl{sub 2}O{sub 4} and Co substituted ZnAl{sub 2}O{sub 4}, PL spectra showed the emission bands in UV as well as in the visible regions, due to the

  8. Synthesis of Sr(1-x-y)Al4O7:Eux 2+,Lny 3+ (Ln = Dy, Y, Pr) nanophosphors using rapid gel combustion process and their down conversion characteristics

    Science.gov (United States)

    Singh, Devender; Tanwar, Vijeta; Samantilleke, Anura Priyajith; Mari, Bernabe; Bhagwan, Shri; Singh, Krishan Chander; Kadyan, Pratap Singh; Singh, Ishwar

    2017-05-01

    Eu2+ and Eu2++Ln3+ doped SrAl4O7 nanophosphors were synthesized by rapid gel combustion process. The morphology of prepared phosphors was examined with scanning and transmission electron microscopy. The phase identification and the crystal structures of nanophosphors were studied using X-ray powder diffraction techniques. Luminescence characteristics of the prepared nanophosphors were analyzed on account of excitation, emission and phosphorescence decay analysis. The emission spectra demonstrated the broad green emission attributed to 4f65d1→ 4f7 transition of the Eu2+ ions. The effect of codoping of some trivalent lanthanide (Dy3+, Pr3+ and Y3+) ions were investigated for improving the emission intensity and phosphorescence decay time of the basic lattice of SrAl4O7:Eu2+ phosphors. The synthesized materials had enhanced bright luminescent properties that could suitably be applied for display as well as photovoltaic applications. [Figure not available: see fulltext.

  9. Study on Preparation and Performance of LaCoO3/γ-Al2O3 Catalysts for Catalytic Combustion%负载型LaCoO3/γ-Al2O3催化剂的制备及性能的研究

    Institute of Scientific and Technical Information of China (English)

    赵文怡; 许延辉; 孟志军; 刘海娇; 张旭霞

    2013-01-01

    LaCoO3/γ-Al2O3 catalysts were prepared by incipient wet impregnation at different calcination temperatures in air.The as-prepared LaCoO3/γ-Al2O3 catalysts were tested for toluene catalytic combustion reaction and were character-ized by XRD and BET.The results shown that LaCoO3/γ-Al2O3 catalysts preared by excessive impregnation had much higher catalytic activity and their structure and properties were more significantly affected by temperature than that prepared by multiple impregnation.With increase in temperature of calcinations,the catalytic activity of the catalysts prepared by excessive impregnation decreased because their specific surface area reduced,the grain size increased,and LaCoO3 crystals were formed.Test of combustion of toluene catalyzed by LaCoO3/γ-Al2O3 calcined at 500℃ with escessive impregnation obtained the results of initial combustion temperature 300℃ and complete combustion temperature 400℃.%分别采用多次浸渍法和过量溶液浸渍法,在不同焙烧温度下制备了LaCoO3/γ-Al2O3催化剂并对其活性进行测试,利用XRD、BET等技术对样品进行了表征.研究表明,过量溶液浸渍法制备的LaCoO3/γ-Al2O3催化剂的活性要明显优于多次浸渍法;多次浸渍法制备样品的催化活性均较低,且受焙烧温度影响较小;焙烧温度对过量溶液浸渍法制备的LaCoO3/γ-Al2O3的结构和性能影响很大,随着焙烧温度的升高,催化剂样品的比表面积逐渐减小,晶粒度变大,有烧结现象,故催化活性降低,且500℃焙烧样品对甲苯催化燃烧的T10%=300℃,T99%=400℃.

  10. Bordieu e a lingüística aplicada

    OpenAIRE

    Maria de Lourdes Otero Brabo Cruz

    1991-01-01

    Procura-se no presente trabalho: (a) analisar as concepções de Bourdieu no que diz respeito à competência lingüística e ao tratamento dos fatos lingüísticos; (b) traçar um paralelo entre essas concepções e a lingüística aplicada; e (c) definir a sua postura como sendo a de um lingüista aplicado.

  11. Bordieu e a lingüística aplicada

    Directory of Open Access Journals (Sweden)

    Maria de Lourdes Otero Brabo Cruz

    2001-02-01

    Full Text Available

    Procura-se no presente trabalho: (a analisar as concepções de Bourdieu no que diz respeito à competência lingüística e ao tratamento dos fatos lingüísticos; (b traçar um paralelo entre essas concepções e a lingüística aplicada; e (c definir a sua postura como sendo a de um lingüista aplicado.

  12. Probabilidade e Estatística Aplicada à Hidrologia

    OpenAIRE

    Guimarães, Rita Cabral

    2011-01-01

    Esta pubilicação pretende ser um manual de auxilio aos alunos na disciplinas de Hidrologia, Hidrologia Agrícola e Interpretação da Paisagem na área da probabilidade e estatistica aplicada à Hidrologia. Abordam-se temas básicos da teoria da estatística e da probabilidade para depois estes serema aplicados na resolução de problemas ligados à Hidrologia

  13. 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.

  14. Técnicas de investigación minera aplicadas a la Arqueología.

    OpenAIRE

    Iraizoz Fernández, José María; Octavio PUCHE RIART; Mansilla Plaza, Luis

    1988-01-01

    Hoy nos encontramos a las puertas de una nueva aplicación para una serie de técnicas mineras que hasta ahora habían tenido su máximo apogeo en una serie de actividades de carácter minero-económico principalmente. Nos estamos refiriendo al campo de la Arqueología, cuya aplicación ha hecho posible la aparición de nuevas ramas de la Ciencia Aplicada como la Arqueofísica, Teledetecci6n en arqueología, etc. A través de ellas se han logrado resultados espectaculares posibilitando una planificación...

  15. Turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

  16. Preparation of Al-MnO2/SBA-15 Catalyst and Its Catalytic Performance for Formaldehyde Combustion%Al-MnO2/SBA-15催化剂的制备 及其催化燃烧甲醛的性能

    Institute of Scientific and Technical Information of China (English)

    杨肖; 贾志刚; 季生福; 张欢; 李旭涛

    2011-01-01

    以介孔分子筛SBA - 15为载体,分别浸渍Mn、Al等催化活性组分,制备了MnO2/SBA-15催化剂和Al-MnO2/SBA-15催化剂.采用X射线衍射、N2吸附-脱附对催化剂的结构进行了表征,在微型固定床反应器上对催化剂的低浓度甲醛催化燃烧性能进行了评价.实验结果表明:MnO2/SBA-15系列催化剂均具有SBA - 15分子筛的介孔结构,活性组分为MnO2,Mn质量分数为20%的催化剂活性最佳,甲醛可在195℃下完全燃烧去除;Al - MnO2/SBA - 15催化剂仍具有SBA - 15分子筛的介孔结构,活性组分为MnO2,没有观测到Al的物相;Mn质量分数为20%、Al质量分数为5%的催化剂活性最好,甲醛在120℃下可完全燃烧去除.%MnO2/SBA-15 catalyst and Al-MnO2/SBA-15 catalyst were prepared by impregnating mesopore zeolite SBA-15 with Mn and Al respectively. The structures of the catalysts were characterized by XRD and N2 adsorption-desorption. The catalytic performances of the catalysts for formaldehyde combustion were evaluated in a fixed-bed microreactor. The experimental results indicate that; MnO2/SBA-15 catalyst has the mesoporous structure of SBA-15, its active component is MnO2; MnO2/SBA-15 catalyst with 20% of Mn mass fraction has the best catalytic activity, formaldehyde can be completely combusted at 195 ℃; Al-MnO2/SBA-15 catalyst has still the mesoporous structure of SBA-15, its active component is MnO2, Al phase is not observed; Al-MnO2/SBA-15 catalyst with 20% of Mn mass fraction and 5% of Al mass fraction has the best catalytic activity, formaldehyde can be completely combusted at 120 ℃.

  17. Synthesis of Y3Al5O12:Tb & Y3Al5O12:Tb,Si phosphor by combustion synthesis: Comparative investigations on the structural and spectral properties

    Science.gov (United States)

    Upasani, Manisha

    2017-02-01

    YAG:Tb polycrystalline powders have been prepared by combustion synthesis at low temperature. Structure and morphology of the obtained materials have been studied. Various structural parameters have been determined by X-ray powder diffraction measurements. Effect of Si codoping on structural and spectral properties have been compared. It has been shown that critical amount of Si found suitable for pure phase formation and enhancement in Tb3+ characteristics green emission in YAG.

  18. Magnetic properties of hard-soft SrFe10Al2O19/Co0.8Ni0.2Fe2O4 ferrite synthesized by one-pot sol-gel auto-combustion

    Science.gov (United States)

    Torkian, Shahab; Ghasemi, Ali; Razavi, Reza Shoja

    2016-10-01

    SrFe10Al2O19/Co0.8Ni0.2Fe2O4 hard/soft nanocomposite ferrites with different content of soft phase have been prepared by simple one-pot sol-gel auto-combustion route. X-ray diffraction (XRD), field emission scanning electron microscopy and vibrating ample magnetometer were employed to analysis of structural and magnetic features of synthesized samples. XRD patterns reflect the formation of hard/soft composites of ferrites without the existence of any kind of secondary phases. Narrow size distributions of particles were formed by sol-gel method. Single smooth hysteresis loops of nanocomposites show the presence of exchange coupling between hard and soft phases. Nanocomposite with 15 wt% of soft phase reaches the highest Mr/Ms ratio of 0.63. Compared to the physical mixing of hard/ soft nanocomposites, the one-pot sol-gel auto-combustion method could be considered as a suitable method for synthesizing exchange coupled magnet.

  19. Study of photoluminescence and thermoluminescence properties of BaAl2O4 (Eu2+, Dy3+) phosphor synthesized by solution combustion method

    Science.gov (United States)

    Pathak, Pushpraj; Kurchania, Rajnish

    2016-10-01

    Eu and Dy co-doped barium aluminate phosphor was successfully synthesized by combustion method using urea as a fuel. Phase formation was confirmed by powder X-ray diffraction (PXRD) analysis. The calculated average crystallite size was found to be ~34.62 nm. Scanning electron microscopy (SEM) images acquired at different (low and high) magnifications reveal that the crystallites have no uniform shape and size. This was due to the non-uniform distribution of temperature and mass flow in the combustion technique. Fourier Transform Infra-red (FTIR) spectrum was recorded to confirm the phase formation and also to identify any impurity if present in the prepared phosphor. Photoluminescence (PL) measurement was carried out to investigate the incorporation of dopant into the host lattice. Thermoluminescence (TL) behaviour of synthesized phosphor was studied after the irradiation with Cobalt-60 gamma rays (Eavg=1.25 MeV) as well as 6 and 16 MV (Mega Voltage) X-ray photons, at various dose levels. The glow curves of irradiated samples exhibit only one peak at 115 °C at each dose level. With the increases of radiation dose an increase in total intensity has been observed. No appreciable shift in peak positions has been observed. Trapping parameters were evaluated to understand the characteristics of prepared phosphor. A simple glow peak with relatively high intensity is one of the important factors, which make this phosphor useful for monitoring the ionizing radiations in nuclear industries, gamma irradiators, high energy accelerators, nuclear reactors etc. where medium and high level of exposure is involved. It could also be applicable for accidental and retrospective dose assessment.

  20. Effect of Fe2O3 Loading Amount on Catalytic Properties of Monolithic Fe2O3/Ce0.67Zr0.33O2-Al2O3 Catalyst for Methane Combustion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ce0.67Zr0.33O2-Al2O3 solid solution was prepared by the co-precipitation method. Fe2O3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe2O3 on Ce0.67Zr0.33O2-Al2O3 in our experimental condition for catalytic combustion of methane was 8%( mass fraction). The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe2O3 was 8%( mass fraction), the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe2O3 was well dispersed on the Ce0.67Zr0.33O2-Al2O3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.

  1. Synthesis, thermal and spectral characterization of nanosized Ni(x)Mg(1-x)Al2O4 powders as new ceramic pigments via combustion route using 3-methylpyrozole-5-one as fuel.

    Science.gov (United States)

    Ahmed, Ibrahim S; Shama, Sayed A; Dessouki, Hassan A; Ali, Ayman A

    2011-10-15

    New Ni(x)Mg(1-x)Al(2)O(4) nanosized in different composition (0.1≤x≤0.8) powders have been synthesized successively for first time by using low temperature combustion reaction (LTCR) of corresponding metal chlorides, carbonates and nitrates as salts with 3-methylpyrozole-5-one (3MP5O) as fuel at 300°C in open air furnace. Magnesium aluminate spinel (MgAl(2)O(4)) was used as crystalline host network for the synthesis of nickel-based nano ceramic pigments. The structure of prepared samples was characterized by using different techniques such as thermal analysis (TG-DTG/DTA), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). UV/Visible and Diffuse reflectance spectroscopy (DRS) using CIE-L*a*b* parameters methods have been used for color measurements. The obtained results reveal that Ni(x)Mg(1-x)Al(2)O(4) powder of samples is formed in the single crystalline and pure phase with average particle size of 6.35-33.11 nm in the temperature range 500-1200°C. The density, particle size, shape and color are determined for all prepared samples with different calcination time and temperature.

  2. Combustion synthesis and luminescence investigation of Na{sub 3}Al{sub 2}(PO{sub 4}){sub 3}:RE (RE = Ce{sup 3+}, Eu{sup 3+} and Mn{sup 2+}) phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Nagpure, I.M., E-mail: indrajitnagpure@yahoo.co.i [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, Free State 9300 (South Africa); Shinde, K.N. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Kumar, Vinay; Ntwaeaborwa, O.M. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, Free State 9300 (South Africa); Dhoble, S.J. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Swart, H.C., E-mail: swarthc@ufs.ac.z [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, Free State 9300 (South Africa)

    2010-03-04

    Rare-earth (Ce{sup 3+}or Eu{sup 3+}) or alkali-earth metal (Mn{sup 2+}) doped Na{sub 3}Al{sub 2}(PO{sub 4}){sub 3} phosphor powder were prepared by a combustion method. Regardless of the dopants, the Na{sub 3}Al{sub 2}(PO{sub 4}){sub 3} was shown to crystallize as hexagonal (rhombohedral) NASICON phase with spheroidal micron sized particles based upon X-ray diffraction (XRD) and scanning electron microscopy (SEM) data. As confirmed by thermogravimetric (TGA) and differential thermal analysis (DTA) data, the powders were stable at high temperatures up to 900 {sup o}C. A broad UV emission (with maximum at 328 nm) associated with the 5d {yields} 4f transition of Ce{sup 3+} was observed from Na{sub 3}Al{sub 2}(PO{sub 4}){sub 3}:Ce{sup 3+} while Mn{sup 2+} and Eu{sup 3+} doping showed stable green and red photoluminescence emission at 515 and 615 nm, respectively. For different molar concentrations of rare-earth/alkali-earth metal dopants, the PL intensity was shown to increase to a certain concentration before quenching occurred at higher concentrations. The structure and optical properties of these phosphors were evaluated.

  3. Advanced Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  4. Removal of Cooking Fume by Catalytic Combustion on Pt/La-Al2O3 + Ce0.5Zr0.5O2 Catalyst

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Four monolithic catalysts with low concentration of noble metal were prepared by the immersion method [ Pt/LaAl2O3, Pt/La-Al2O3 + Pt/OSM (2∶1), Pt/La-Al2O3 + Pt/OSM (1∶1) Pt/La-Al2O3 + Pt/OSM (1∶2)], and measurements of their activity were carried out in a conventional fixed-bed flow reactor. The results show that the oxygen storage material (OSM) that is added can promote the activity of the prepared catalysts and can decrease the complete conversion temperature of cooking fume. When the ratio between La-Al2O3 and OSM is 1∶ 1, the catalyst has the highest activity, and the complete conversion temperature of cooking fume is 270 ℃; the catalyst thus prepared can be applied in a wide range of gas hourly space velocity (GHSV) [from 10000 to 60000 h-1 ]. The catalyst obtained shows great potential for practical application.

  5. Turbulent Combustion in SDF Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-11-12

    A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

  6. Las Perspectivas y Retos de la Antropología Aplicada en el Siglo XXI

    Directory of Open Access Journals (Sweden)

    Marisol Pérez L.

    2007-01-01

    Full Text Available El presente artículo reflexiona acerca del rol de la Antropología aplicada en el siglo XXI. Analiza las posibilidades de la antropología aplicada en el contexto actual, sus fortalezas y debilidades frente a los problemas sociales contemporáneos.

  7. Synthesis by combustion reaction of ZnAl{sub 2}O{sub 4} and application in methyl alcoholysis of soybean oil; Sintese por reacao por combustao do ZnAl{sub 2}O{sub 4} e sua aplicacao na alcoolise metilica do oleo de soja

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, B.B.; Silva, A.S. [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Unidade Academica de Engenharia Quimica; Cunha, R.B.L.; Leal, E.; Costa, A.C.F.M., E-mail: anacristina@dema.ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Unidade Academica de Engenharia de Materiais

    2011-07-01

    Biodiesel currently presents itself as a viable alternative to diesel oil front. However, implementation of actions most economic use as heterogeneous catalysts, allows further reduction of this biofuel by procedural steps. This work was supported application of catalytic ZnAl{sub 2}O{sub 4} obtained by combustion reaction in methyl alcoholysis of soybean oil. Samples of the supports were characterized by XRD, textural analysis by nitrogen adsorption and FTIR. The reaction tests were performed at 200°C, molar ratio 1:25, 2 and 4 wt% of catalyst and reaction time of 3 hours. XRD results indicate that the phase was obtained ZnAl{sub 2}O{sub 4} effectively, with surface areas of 14.9 and 8.6 m{sup 2} g{sup -1}. The tests demonstrated that reactional higher content of ester was 56.1 and 63.1% for the percentage of catalyst 2 and 4% respectively. (author)

  8. Evolución de la enseñanza de la estadística aplicada a la psicología

    OpenAIRE

    Rossi Casé, Lilia Elba; Biasella, Rogelio; Doná, Stella Maris; Farinon, Eliana

    2011-01-01

    En el intento de transmitir un conocimiento, o tal vez a causa de ella, al finalizar los cursos de Estadística Aplicada a la Psicología, de la Facultad de Psicología de la Universidad Nacional de La Plata, la mayoría de los alumnos no están en condiciones de explicar claramente la lógica implícita en las técnicas que han aprendido. De este aprendizaje, se han tomado dos aspectos metodológicos básicos para optimizar la construcción de los conceptos que hacen a la Estadística aplicada: Poner el...

  9. Fabrication of Fe-TiC-Al2O3 composites on the surface of steel using a TiO2-Al-C-Fe combustion reaction induced by gas tungsten arc cladding

    Science.gov (United States)

    Sharifitabar, Mahmood; Khaki, Jalil Vahdati; Sabzevar, Mohsen Haddad

    2016-02-01

    The aim of the present study was to fabricate Fe-TiC-Al2O3 composites on the surface of medium carbon steel. For this purpose, TiO2-3C and 3TiO2-4Al-3C- xFe (0 ≤ x ≤ 4.6 by mole) mixtures were pre-placed on the surface of a medium carbon steel plate. The mixtures and substrate were then melted using a gas tungsten arc cladding process. The results show that the martensite forms in the layer produced by the TiO2-3C mixture. However, ferrite-Fe3C-TiC phases are the main phases in the microstructure of the clad layer produced by the 3TiO2-4Al-3C mixture. The addition of Fe to the TiO2-4Al-3C reactants with the content from 0 to 20wt% increases the volume fraction of particles, and a composite containing approximately 9vol% TiC and Al2O3 particles forms. This composite substantially improves the substrate hardness. The mechanism by which Fe particles enhance the TiC + Al2O3 volume fraction in the composite is determined.

  10. Análise do conceito de tecnologia educacional em enfermagem aplicada ao paciente

    Directory of Open Access Journals (Sweden)

    Aline Cruz Esmeraldo Áfio

    2014-01-01

    Full Text Available El objetivo fue analizar el concepto de tecnología educacional, producido por la Enfermería, aplicada al paciente. Se utilizó el Modelo de Evolución de Análisis del Concepto, identificándose antecedentes, atributos, y consecuentes. Se seleccionaron 13 artículos para análisis, donde se identificaron los antecedentes: deficiencia de conocimiento, escasez de tiempo de los profesionales de enfermería, optimización del trabajo da enfermería, necesidad de alcanzar metas de pacientes; atributos: herramienta, estrategia, abordaje innovador, enfoque pedagógico, mediadora de conocimientos, forma creativa de estimular la adquisición de competencias, instrumento de producción de salud; consecuentes: mejora de calidad de vida, estímulo a comportamientos saludables, empoderamiento, reflexión y vínculo. Se enfatiza la importancia de las tecnologías educacionales para la atención de enfermería, al dinamizar actividades de educación en salud.

  11. 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...

  12. 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...

  13. Synthesis of Y{sub 1-x}Al{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-δ} via combustion route: Effects of Al{sub 2}O{sub 3} nanoparticles on superconducting properties

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Suan, Mohd Shahadan, E-mail: mohdshahadan@utem.edu.my [Department of Engineering Materials, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76100 Durian Tunggal, Melaka (Malaysia); Johan, Mohd Rafie [Nanomaterial Engineering Research Group, Advanced Materials Research Laboratory, Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2017-02-01

    Combustion reaction was used to synthesis Al{sub 2}O{sub 3} nanoparticles embedded Y{sub 1-x}Al{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-δ} simultaneously. The effects of Al{sub 2}O{sub 3} nanoparticles with nominal molar mass (x{sub mol}) of 0.02, 0.04, 0.06, 0.08 and 0.10 towards the critical current density J{sub C} of Y{sub 1-x}Al{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-δ} were verified by magnetic measurement. Resulted XRD patterns revealed that the calcined samples consist of pure Al{sub 2}O{sub 3} and Y{sub 1-x}Al{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-δ} phases which had been confirmed by EDX results. The SEM images showed that Al{sub 2}O{sub 3} nanoparticles (~10 nm) were distributed in polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-δ} grains and grain boundaries. The presence of higher concentration of Al{sub 2}O{sub 3} nanoparticles has developed Al{sup 3+} rich spots which diffused within the YBa{sub 2}Cu{sub 3}O{sub 7-δ} superconducting matrix to form Y{sub 1-x}Al{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-δ} and was confirmed by EDX analysis. The samples were electrically superconducting at temperature above 85 K as measured by using standard four-probe technique. The magnetic field (H) dependent magnetization (M), M-H hysteresis loops measured at 77 K for x{sub mol}≤0.06 samples are significantly improved attributed to the increase of trapped fluxes in the samples. Remarkable increase of magnetic J{sub C} (H) in Al{sub 2}O{sub 3} nanoparticles added samples compared to the as prepared polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-δ} sample indicating strong pinning effect. It is suggested that well-distributed Al{sub 2}O{sub 3} nanoparticles in the polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7-δ} matrix achieved via auto-combustion reaction has efficiently pin the magnetic vortex. The magnetic J{sub C} was optimized to ~6 kAcm{sup -2} in x{sub mol}=0.06 sample. On the other hand, insignificant magnetic J{sub C} improvement in x{sub mol}≥0.08 samples is probably resulted from the

  14. Y3Al5O12:Re3+ (Re=Ce, Eu, and Sm nanocrystalline powders prepared by modified glycine combustion method

    Directory of Open Access Journals (Sweden)

    Lojpur V.

    2014-01-01

    Full Text Available Yttrium aluminum garnet doped with rare earth ions (Ce3+, Eu3+ and Sm3+ was prepared by modified glycine method. Ce3+ as a dopant was used in four different concentrations (Y3-xCexAl5O12; x(% = 1, 2, 3, 5, while doping concentration of Eu3+ and Sm3+ was Y3-xEuxAl5O12; x(% = 3 and Y3-xSmxAl5O12; x(% = 1, respectively. Phase composition of powders was investigated using XRD technique and expected target phase was confirmed. Photoluminescent characterization included measurements of excitation and emission spectra, as well as determination of emission decays. Y3-xCexAl5O12 shows intense broad-band emission, with maximum in green spectral region, at about 524 nm under ultraviolet or blue excitation. The origin of the luminescence is the 5d1→4f1 transition which is both parity and spin allowed. Ultraviolet and blue excitations of Eu3+ and Sm3+ doped Y3Al5O12 produce intense orange and red emissions. These emissions are phosphorescent in character and come from spin forbidden f-f electron transitions in Eu3+ and Sm3+ ions. For the case of Eu3+ doping emission comes mainly from 5D0→7F1 transitions with Stark components peaking at 590 nm and 590.75 nm, and with emission decay of 4.15 ms. In the case of Sm3+ doping, the emission spectrum, shows 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2 transitions, with the most intense stark components positioned at 567.5 nm, 617 nm, and 650 nm, respectively and for transition centered at 617 nm, emission decay is 3.12 ms. [Projekat Ministarstva nauke Republike Srbije, br. 171022 i br. 45012

  15. Ciencia básica y ciencia aplicada

    OpenAIRE

    Pérez-Tamayo Ruy

    2001-01-01

    En el contexto de una intervención en el Foro de Consulta Democrática de la Coordinación de los Institutos Nacionales de Salud sobre Enseñanza e Investigación en Salud, realizado en el Instituto Nacional de Cardiología Ignacio Chávez, se hace una revisión crítica de la clasificación convencional de la ciencia en básica y aplicada; además, se analiza lo que deberían ser la enseñanza y la investigación en salud. Para apoyar su propia clasificación de la ciencia en "bien hecha", la cual "genera ...

  16. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  17. Análisis de la productividad y el consumo de combustible en conjuntos de labranza en un fluvisol para el cultivo de la yuca (Manihot esculenta, Crantz

    Directory of Open Access Journals (Sweden)

    Hugo Berto Vázquez Milanés

    2012-01-01

    Full Text Available El trabajo fue realizado en la UBPC "El Palmar" perteneciente a la Empresa de Cultivos Varios "Paquito Rosales Benítez" del municipio de Yara, provincia de Granma. La investigación se llevó a cabo en el período de abril del 2007 a enero del 2008, el método utilizado fue el analítico investigativo y la técnica aplicada el fotocronometraje. Se evaluaron los conjuntos máquina tractor que intervienen en la realización de cuatro tecnologías de labranza (T1, T2, T3 y T4 para el cultivo de la yuca, variedad Enana Rosada. Se realizaron cinco observaciones de la jornada laboral para cada uno de los conjuntos, evaluando el consumo de combustible y la productividad. Los mejores resultados de los indicadores evaluados a la maquinaria correspondieron a la tecnología de laboreo mínimo T2 con Subsolador Bayamo Modificado y grada de discos: productividad por hora de tiempo limpio (1,34 ha h-1 y de tiempo operativo (1,27 ha h-1 con diferencias significativas respecto al resto de las tecnologías evaluadas, así como el menor consumo de combustible (32,4 L ha-1; se reduce éste en un porcentaje de un 72; 52 y 71 % respecto a T1, T3 y T4.

  18. Metodología de simulación del almacenamiento geológico de CO2 como contribución a la solución al problema del Cambio Climático, aplicada a la estructura BG-GE-08 (oeste de la Comunidad de Murcia)

    OpenAIRE

    Arjona García-Borreguero, Javier

    2015-01-01

    Una de las medidas de mitigación del Cambio Climático propuestas al amparo de la ONU por el IPCC (Intergovermental Panel on Climate Change) en su ‘Informe de Síntesis 2007’ consiste en la puesta en marcha de acciones para la captación y almacenamiento de dióxido de carbono, existiendo tres tipos de formaciones geológicas idóneas para el almacenamiento geológico de este gas: yacimientos de petróleo y gas agotados, capas de carbón no explotables y formaciones salinas profundas. En el caso de l...

  19. Combustion synthesis of TiC/Ti-Al based composites%TiC/Ti-Al基复合材料的燃烧合成

    Institute of Scientific and Technical Information of China (English)

    朱春城; 钱旭坤; 张爱军; 李庆芬; 赫晓东

    2009-01-01

    为了改善Ti-Al金属间化合物的脆性,利用SHS/PHIP工艺制备了TiC/Ti-Al基复合材料.理论分析表明,绝热温度随C质量分数的增加而呈升高趋势,当体系中碳的质量分数≥2%时,该体系能完成自蔓延过程.采用电子扫描显微镜,X射线衍射仪对合成产物进行了分析.结果表明,合成产物中除存在基体相Ti_3Al和TiAl和增强相TiC外,还存在许多三元相Ti_3AlC和Ti_2AlC相;随着Al质量分数的增加,增强相的形貌由颗粒状逐渐变成棒状或片状;复合材料的硬度和压缩强度随C质量分数的增加逐渐增加,但密度及相对密度随C质量分数的增加呈先增加后降低的趋势.当C的质量分数达到4%时,其实际密度和相对密度均达到最大.

  20. Morfometría dental aplicada al análisis de los procesos de diferenciación poblacional en el sudeste de la Región Pampeana y norte de Patagonia durante el Holoceno Tardío

    Directory of Open Access Journals (Sweden)

    Bernal, Valeria

    2005-01-01

    Full Text Available El objetivo del presente trabajo es analizar la variabilidad en la morfometría dental en muestras de restos óseos humanos del SE de la Región Pampeana asignables a distintos momentos del Holoceno tardío y comparar, desde un punto de vista espacial, el grado de similitud morfológica con muestras procedentes del NE de Patagonia (valles de Río Negro y Chubut, San Blas, Isla Gama. Se relevaron los diámetros mesiodistal y bucolingual medidos a nivel del margen cervical en la totalidad de las piezas dentales permanentes correspondientes a 130 individuos de ambos sexos. Las medidas obtenidas fueron empleadas en análisis estadísticos multivariados con el fin de evaluar el grado similitud morfológica entre las muestras. Los resultados obtenidos indican que: 1- hay diferencias entre las muestras procedentes del SE de la Región Pampeana correspondientes al Holoceno tardío inicial y final, caracterizándose estas últimas por un mayor tamaño dental; 2- la muestra del SE de la Región Pampeana correspondiente al Holoceno tardío final presenta mayor similitud morfológica con la muestra más tardía del valle de Río Negro; 3- existen variaciones cronológicas en el tamaño dental entre las muestras procedentes del NE de Patagonia.

  1. Synthesis of SrAl2O4:Eu2+,Dy3+ Nanometer Phosphors by Detonation and Combustion Method%爆轰和燃烧法合成SrAl2O4:Eu2+,Dy3+纳米发光粉

    Institute of Scientific and Technical Information of China (English)

    曲艳东; 李晓杰; 赵铮; 欧阳欣

    2008-01-01

    The SrAl2O4:Eu2+,Dy3+(SED) nanometer phosphors were synthesized at lower temperature by detonation and combustion method,respectively.The effects of synthesis conditions,annealing temperature on the growth behavior,the particle morphologies and optical properties of the as-prepared SED particles were contrasted.It was showed that the mean size of the SED particles prepared by detonation method increased gradually with increasing heat treatment,and that the mean size of the SED particles prepared by combustion method decreased firstly and then increased quickly and had a minimal value at 600 ℃.The mean size of the SED particles prepared by detonation method increased more quickly than that of the SED particles prepared by combustion method at same annealing temperature.Finally,the mechanism for the long afterglow was discussed and some suggestions on how to improve the synthesis methods were also presented.%在低温条件下分别用爆轰法和燃烧法制备出了SrAl2O4:Eu2+,Dy3+纳米发光粉.从合成条件、热处理温度等方面详细对比了爆轰法和燃烧法对所制备的SrAl2O4:Eu2+,Dy3+纳米发光粉的晶体生长行为、粒子形貌和光学性质等的影响.研究表明,随着热处理温度的升高,爆轰法制备的纳米发光粉的平均粒径逐渐增大,而燃烧法制备的纳米发光粉的平均粒径先减小后增大,在600 ℃时平均粒径存在一个极小值.在同样热处理温度下,爆轰法制备的纳米发光粉的平均粒径增长明显高于燃烧法合成的纳米发光粉的平均粒径.最后讨论了长余辉的发光机理,并给出了如何改进合成方法的建议.

  2. 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

  3. Effect of 2,4-Dihydroxybenzoate Lead/Cupric on Combustion Properties of Al/RDX-CMDB Propellants%2,4-二羟基苯甲酸铅铜盐对Al/RDX-CMDB推进剂燃烧性能的影响

    Institute of Scientific and Technical Information of China (English)

    袁志锋; 赵凤起; 焦建设; 张教强; 杨立波; 郑晓东; 张超; 谢波

    2014-01-01

    为了研究2,4-二羟基苯甲酸铅铜盐(Pb/Cu-SDHB)单独或与其它催化剂复合后对含Al粉和黑索今(RDX)改性双基(Al/RDX-CMDB)推进剂燃烧性能的影响,采用吸收-压延方法制备了推进剂样品,用靶线法测试了推进剂燃速。结果表明:Pb/Cu-SDHB能有效调节推进剂燃烧性能,显著提高了Al/RDX-CMDB推进剂的燃速,并明显降低了压强指数;3.0%Pb/Cu-SDHB与0.65%炭黑复合后使Al/RDX-CMDB推进剂在10~15MPa的压强指数降低至-0.1,10MPa下燃速超过20mm/s。%In order to investigate the effects of lead/cupric salt of 2,4-dihydroxybenzoate(Pb/Cu-SDHB)itself, or composite with other catalysts on the combustion properties of Al/RDX-CMDB propellant, the propellant samples were prepared through a solventless extrusion technique, as well as the burning rate of propellants were measured by stand burner method .The results showed that Pb/Cu-SDHB could increase the burning rate and reduce the pressure exponent of Al/RDX-CMDB propellant notably. When 3.0%Pb/Cu-SDHB composited with 0.65%carbon, the pressure exponent of Al/RDX-CMDB propellant reduced to-0.1 under 10~15MPa, and the burning rate at 10MPa would exceed 20mm/s.

  4. Al-RDX-CMDB推进剂燃烧催化机理和模型的研究%Study of Mechanism and Model for Catalyzed Combustion of Al-RDX-CMDB Propellant

    Institute of Scientific and Technical Information of China (English)

    宋洪昌; 王祎; 白华萍

    2004-01-01

    在原有的RDX-CMDB推进剂稳态燃烧化学--数学模型基础上,通过对铝粉燃烧机理的研究及大量燃速数据的分析,采用归纳因子的方法寻求铝粉的含量和粒度对燃速的影响因子,建立了Al-RDX-CMDB推进剂燃速计算公式.运用该公式可从化学结构出发,计算Al-RDX-CMDB推进剂的燃速和压强指数.通过实际计算表明,理论燃速值与实测值十分一致.由此讨论了影响平台推进剂燃速与燃速压强指数的化学结构因素.

  5. Combustion Behaviour of Advanced Solid Propellants.

    Directory of Open Access Journals (Sweden)

    S. N. Asthana

    1993-07-01

    Full Text Available The study reports the effect of incorporation of Al and ammonium perchlorate (AP individually and in combination with each other on combustion pattern and specific impulse (Isp of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions.

  6. Oxygen-enhanced combustion

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissions as well as increased energy efficiency and productivity. Oxygen-Enhanced Combustion, Second Edition compiles information about using oxygen to enhance industrial heating and melting processes. It integrates fundamental principles, applications, a

  7. Persistent luminescence, TL and OSL characterization of beta irradiated SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} combustion synthesized phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Zúñiga-Rivera, N.J. [Departamento de Física, Posgrado en Nanotecnología, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); García, R.; Rodríguez-Mijangos, R.; Chernov, V.; Meléndrez, R.; Pedroza-Montero, M. [Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Barboza-Flores, M., E-mail: mbarboza@cifus.uson.mx [Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico)

    2014-05-01

    The persistent luminescence (PLUM), thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of strontium aluminates co-doped with Eu{sup +2} and Dy{sup +3} exposed to beta radiation is reported. The phosphor was synthesized by the combustion synthesis method employing a highly exothermic redox reaction between the metal nitrates [Al(NO{sub 3}){sub 3}, Sr(NO{sub 3}){sub 2}, Eu(NO{sub 3}){sub 3} and Dy(NO{sub 3}){sub 3}] and organic fuel carbohydrazide (CH{sub 6}N{sub 4}O). The long decay PLUM emission, TL and OSL were measured as a function of beta radiation dose. A wide emission band centered at 510 nm (green) related to Eu{sup 2+} ions and lattice defects were observed for the synthesized samples. The presence of a variety of defects and aggregates were responsible for the observed broad 100 °C peaked TL glow curve of the irradiated sample which is composed of several overlapped TL peaks. The existence of multiple trapping levels, with different trapping/detrapping probabilities, is behind the particular features for the PLUM, TL and OSL emissions. We conclude that in the SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} phosphors, the low temperature TL peaked around 30–75 °C is responsible for the PLUM emission and those around 100 °C were related to very stable trapping states which provide suitable radiation storage properties to be used as a PLUM/TL/OSL radiation phosphor.

  8. La atención psicológica a pacientes con cáncer: de la evaluación al tratamiento. 1er Premio de la XIX edición del Premio de Psicología Aplicada “Rafael Burgaleta” 2012

    Directory of Open Access Journals (Sweden)

    Manuel Hernández

    2013-01-01

    Full Text Available El cáncer genera un importante sufrimiento psicológico que alcanza niveles de malestar emocional clínicoen la mitad de las personas que lo padecen y se acompaña de trastornos psicopatológicos en más del 30%de los casos, una prevalencia superior a la de la población general, que precisa atención psicológica especializada.El malestar emocional es alto desde el inicio hasta el final de los tratamientos médicos y es unfactor de riesgo de trastornos psicopatológicos. Estos problemas requieren una adecuada detección y evaluación,a menudo obstaculizada por distintos motivos. Se necesitan herramientas sencillas, de fácil aplicaciónen las consultas médicas y adecuadas para detectar el malestar emocional y los problemas de saludmental que pueden sufrir estas personas; con ello se facilitaría la derivación de estos pacientes a la consultadel psicooncólogo para dar el tratamiento específico a los que lo precisen, en el contexto de la atenciónintegral al paciente oncológico. Este objetivo compromete a todos los sanitarios.

  9. 负载于HZSM-5上的CuO-ZnO-Al2O3纳米粒子:尿素-硝酸盐燃烧合成和理化表征%Urea-Nitrate Combustion Synthesis and Physicochemical Characterization of CuO-ZnO-Al2O3 Nanoparticles over HZSM-5

    Institute of Scientific and Technical Information of China (English)

    Reza Khoshbin; Mohammad Haghighi

    2012-01-01

    A series of CuO-ZnO-Al2O3 nanocomposites over HZSM-5(CZA/HZSM-5)have been synthesized by urea-nitrate combustion method.The influence of the fuel to oxidant ratio on the physicochemical properties of synthesized nanocomposites has been studied.The thermal decomposition of urea-nitrate gels and the phase evolution of calcined powder were investigated by TGA/DTG,FTIR and XRD techniques.The FESEM results show that the properties of the CZA/HZSM-5 are significantly influenced by fuel content used in the combustion process.The crystalline size of the CuO and ZnO initially increases with the increase in urea content and then decreases with further addition of urea.The relative crystallinity of CuO and ZnO shows non monotonic trend with increasing of fuel content.With increasing of fuel to nitrate ratio,not only the morphology of the CZA/HZSM-5 becomes ultra-fine and homogeneous,but also the surface porosity increases obviously.FTIR results show that HZSM-5 structure is not damaged even after loading with CuO-ZnO-Al2O3 nanoparticles and there are external linkages between CuO and ZnO with HZSM-5.TGA/DTG curves indicate that the combustion synthesis method is a combination of several phenomena such as thermal decomposition of precursors and exothermal reactions between them.Furthermore,a formation channel of CuO-ZnO-Al2O3 over HZSM-5 was proposed.%用尿素-硝酸盐燃烧法制备了一系列的负载于HZSM-5上的CuO-ZnO-Al2O3纳米复合材料(CZA/HZSM-5).研究了燃料与氧化物的比率对所合成的复合材料的理化性质的影响.用TGA/DTG,FTIR和XRD等研究了尿素-硝酸盐凝胶的热分解和煅烧粉体的相演变过程.FESEM结果表明在燃烧过程中燃料的用量对CZA/HZSM-5的性质有重大影响.CuO和ZnO的晶粒首先随尿素量的增加而增大,然后随尿素量的增加而减小.CuO和ZnO的相对结晶度随燃料量的增加表现为非单调趋势.随着燃料与硝酸盐的比率的增加,CZA/HZSM-5不仅形貌变得超细和

  10. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  11. Combustion 2000

    Energy Technology Data Exchange (ETDEWEB)

    A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

    2001-06-30

    . To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization

  12. PSICOLOGIA APLICADA À ODONTOPEDIATRIA: UMA INTRODUÇÃO

    Directory of Open Access Journals (Sweden)

    Áderson Luiz Costa Junior

    2013-10-01

    Full Text Available Apresenta-se, aqui, a psicologia aplicada à odontologia como um corpo de conhecimentos da psicologia clínica da saúde útil à avaliação e manipulação do repertório de comportamentos de indivíduos, especialmente crianças, expostos a tratamento odontológico, cuja situação é percebida como ameaçadora e/ou potencialmente aversiva. Discutem-se a aquisição e a manutenção de respostas de medo de dentista em crianças e as variáveis psicossociais que medeiam os processos de diagnóstico, tratamento e reabilitação em odontopediatria. Apresentam-se alguns procedimentos psicológicos de manipulação de repertório de comportamentos de pacientes aplicados à situação de consultório de odontologia. Pretende-se, assim, estimular a formação acadêmica e profissional do psicólogo para atuação em contextos de odontologia e de saúde de modo geral.

  13. 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.

  14. Al-RDX-CMDB推进剂燃烧催化机理和模型的研究%Study of Mechanism and Model for Catalyzed Combustion of Al-RDX-CMDB Propellant

    Institute of Scientific and Technical Information of China (English)

    宋洪昌; 王祎; 白华萍

    2004-01-01

    在原有的RDX-CMDB推进剂稳态燃烧化学--数学模型基础上,通过对铝粉燃烧机理的研究及大量燃速数据的分析,采用归纳因子的方法寻求铝粉的含量和粒度对燃速的影响因子,建立了A1-RDX-CMDB推进剂燃速计算公式.运用该公式可从化学结构出发,计算Al-RDX-CMDB推进剂的燃速和压强指数.通过实际计算表明,理论燃速值与实测值十分一致.由此讨论了影响平台推进剂燃速与燃速压强指数的化学结构因素.

  15. Synthesis NiAl{sub 1,0}Fe{sub 1,0}O{sub 4} catalyst by the combustion reaction to their use in the shift reaction (WGSR); Sintese do catalisador de NiAl{sub 1,0}Fe{sub 1,0}O{sub 4} por reacao de combustao visando sua utilizacao na reacao de shift (WGSR)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, P.T.A.; Costa, A.C.F.M.; Neiva, L.S.; Gama, L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Argolo, F.; Andrade, H.M.C. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2009-07-01

    This work aims at the synthesis of catalyst NiAl{sub 1,0}Fe{sub 1,0}O{sub 4} by combustion reaction using urea as fuel, to evaluate its performance in the production of hydrogen by the reaction of displacement of water vapor (WGSR). The initial composition of the solution was based on valencia total oxidizing and reducing reagents based on the concepts of the chemistry of propellants, using container as a crucible of glassy silica. The resulting powder was characterized by X-ray diffraction, infrared spectroscopy, nitrogen adsorption isotherms (BET), scanning electronic microscope and catalytic tests. The DRX results reveal the presents majoritary phase NiAl{sub 1,0}Fe{sub 1,0}O{sub 4} spinel, the catalyst presents surface area 28 m{sup 2}/g and isotherms type III. Higher conversion CO/CO{sub 2} of 75% CO conversion observed at 500 deg C and catalytic activity of 43 mmolg{sup -1}.h{sup -1} at 450 deg C. (author)

  16. Evaluation of the urea content in the synthesis by combustion reaction of the NiAl{sub 2}O{sub 4} catalysts; Avaliacao do teor de ureia na sintese por reacao de combustao do catalisador NiAl{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Leal, E.; Sousa, J.-P.L.M.L.; Costa, A.C.F.M.; Gama, L. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Argolo, F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Sasaki, J.M. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica

    2009-07-01

    The aim of this work is to evaluate the influence of the urea fuel in the structure and morphology of the NiAl{sub 2}O{sub 4} prepared by combustion reaction. The powders were prepared according to the propellants and explosives theory, using urea in the stoichiometric composition, with 10% of excess and deficiency of this fuel. The samples were characterized by XRD, FTIR, particle size distribution and textural analysis by nitrogen adsorption (BET/BJH). The DRX results showed the presence of NiAl{sub 2}O{sub 4} as major phase and traces of NiO for all the samples. Also show crystallites size between 13 and 21 nm. All the samples showed large agglomerates size distribution, with D{sub 50%} between 18.6 and 20.4 {mu}m, and morphology with irregular plates shape. The increase of the urea content caused an increase in the particle size and a reduction in the surface area, from 270 to 52 m{sup 2}/g. (author)

  17. On supersonic combustion

    Institute of Scientific and Technical Information of China (English)

    袁生学

    1999-01-01

    Some basic concepts and features of supersonic combustion are explained from the view point of macroscopic aerodynamics. Two kinds of interpretations of supersonic combustion are proposed. The difference between supersonic combustion and subsonic combustion is discussed, and the mechanism of supersonic combustion propagation and the limitation of heat addition in supersonic flow are pointed out. The results of the calculation of deflagration in supersonic flow show that the entropy increment and the total pressure loss of the combustion products may decrease with the increase of combustion velocity. It is also demonstrated that the oblique detonation wave angle may not be controlled by the wedge angle under weak underdriven solution conditions and be determined only by combustion velocity. Therefore, the weak underdriven solution may become self-sustaining oblique detonation waves with a constant wave angle.

  18. 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...

  19. Effect of Propellant Combustion on Sapphire

    Directory of Open Access Journals (Sweden)

    Mark L. Bundy

    2000-10-01

    Full Text Available Sapphire (Al2O3 is the window material of choice for laser beam transmission into the combustion chamber of laser-ignited guns. To evaluate the long-term effects of propellant combustion on an Al/sub 2/O/sub 3/ laser window, it is important to know the window temperature during firing. This paper presents temperature data on an Al/sub 2/O/sub 3/ sample located in the breech face of the gun where the laser window would be in a laser-ignited 155 mm(M199 cannon. Al/sub 2/O/sub 3/ sample is a substrate material of a commercially sold thin-film thermocouple, and is therefore thermally, if not optically, representative of an actual Al/sub 2/O/sub 3/ laser window.

  20. Experimental modal tests applied to rotor balancing; Pruebas modales experimentales aplicadas al balanceo de rotores

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Solis, Jose Antonio; Munoz Quezada, Rodolfo; Franco Nava, Jose Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1993-01-01

    At the Instituto de Investigaciones Electricas (IIE), the experimental modal tests were initiated in order to validate the numerical models used by computer programs for the study of the rotor dynamic behavior. In order to contribute to the application of the rotor balancing methods based in the calculation of their modal forms, currently the capacity to determine these modal forms and the natural frequencies of turbogenerator rotors, is being developed, through experimental modal tests. In this paper a short description is made of the technique and the results of its application in an experimental rotor and in one of the rotors of a turbogenerator, are presented. [Espanol] En el Instituto de Investigaciones Electricas (IIE), las pruebas modales experimentales se iniciaron con la finalidad de validar los modelos numericos empleados por programas de computo para el estudio del comportamiento dinamico de rotores. Con objeto de contribuir a la aplicacion de los metodos de balanceo de rotores basados en el calculo de sus formas modales, actualmente esta desarrollandose la capacidad para determinar esas formas modales y las frecuencias naturales de rotores de turbogeneradores, a traves de las pruebas modales experimentales. En este trabajo se describe brevemente la tecnica y se presentan los resultados de su aplicacion en un rotor experimental y en uno de los tres rotores de un turbogenerador.

  1. Musicoterapia aplicada al desarrollo del lenguaje en alumnos con Síndrome de Down

    OpenAIRE

    Cabezudo Unzueta, María del Henar

    2015-01-01

    En la actualidad son muchas las terapias que surgen como alternativas a los convencionales métodos de tratamiento. En el ámbito de la Educación Especial una de las técnicas empleadas es la Musicoterapia, debido a su amplia aplicación en alumnos con necesidades educativas específicas (discapacidad intelectual, autismo, parálisis cerebral, trastorno por déficit de atención e hiperactividad...) además de sus beneficios en la prevención y mejora de la salud física, mental y emocional que produce ...

  2. Laser metrology applied to the nuclear maintenance; Metrologia laser aplicada al mantenimiento nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Garrido Garcia, J.; Sarti Fernandez, F.

    2012-07-01

    The development of this paper focuses on providing an overview of the state of the art about laser metrology. This type of equipment combines the measurement philosophy of laser scanning with the great precision of the robotic equipment of auscultation. Getting micron.

  3. Visión artificial aplicada al control de la calidad

    OpenAIRE

    GARCÍA FUENTES, JORGE; NAVALÓN DAVÓ, ABRAHAM; Jordà Reolid, Antoni; Juárez Varón, David

    2014-01-01

    [EN] In the last years production systems have significantly evolved by seeking to maximize productivity. All new philosophies and manufacturing techniques are among its main targets to maximize quality, a key factor for improving competitiveness. In this article the main systems of vision quality processes are discussed, focusing on three key areas: textile industry, food industry and medical applications; analyzing current applications, seeking the advantages and disadvantages obtained. ...

  4. Realidad virtual inmersiva aplicada al aprendizaje de geometría del espacio

    OpenAIRE

    Torner Ribé, Jordi; Alpiste Penalba, Francesc; Brigos Hermida, Miguel Ángel; Embodas, Robert

    2014-01-01

    Proponemos investigar las posibilidades de utilizar entornos virtuales inmersivos para mejorar la habilidad espacial de los estudiantes de ingeniería a partir del estudio de la geometría del espacio (solid geometry). La hipótesis que se quiere contrastar es que los estudiantes que utilizan el entorno IVLE (Immersive Virtual Learning Environment) presentan una mejora significativa de las habilidades espaciales así como los resultados académicos respecto de aquellos que no lo utilizan. Esto nos...

  5. Electrocoagulación aplicada al tratamiento de efluentes generadospor empresas de mantenimiento de motores.

    Directory of Open Access Journals (Sweden)

    Alicia Guevara

    2011-05-01

    Full Text Available La electrocoagulación es una operación que desestabiliza una emulsión y permite altos porcentajes de remoción de demanda química de oxígeno (DQO y turbiedad. En el presente trabajo se evaluó la electrocoagulación como técnica de tratamiento no convencional de efluentes generados por empresas de Mantenimiento de motores y para la evaluación de la operación se midieron los parámetros: DQO, tensoactivos, sólidos suspendidos y totales, turbiedad y concentración de aluminio, cobre y cinc. El efluente estudiado se caracterizó por ser altamente heterogéneo, así la DQO varió entre 10 500 mg/l y 14 700 mg/l. La turbiedad desde 619 NTU a 886 NTU. El rango de tensoactivos desde 86,6 mg/l a 221, 6 mg/l. La concentración inicial de aluminio fue 88 mg/l, de cobre fue 123 mg/l y de cinc fue 13 mg/l. La concentración inicial de sólidos suspendidos fue 340 mg/l y la concentración de sólidos totales fue 10 456 mg/l. En la investigación se establecieron los valores de las variables que influyen en la electrocoagulación para hacerla eficiente. El pH de operación que presenta mejores resultados es 9,7. La intensidad de corriente que se determinó como la más eficiente es de 1,8 A. Con esta intensidad de corriente se tiene una remoción de DQO de 32%, remoción de sólidos suspendidos de 98,3 %, remoción de turbiedad de 97,4 % y remoción de aluminio 88%, de cobre 87% y de cinc de 99%, El tiempo de residencia que requiere la operación es de 60 minutos.

  6. Factores determinantes de las Medidas No Arancelarias aplicadas al comercio agroalimentario

    OpenAIRE

    Tudela Marco, Lorena

    2016-01-01

    [EN] The Non-Tariff Measures (NTMs) include a wide range of issues; those that cover food safety, animal health and plant protection, are known as Sanitary and Phytosanitary (SPS). SPS are a key element in the agrifood trade and a major challenge for trade policy and food safety. The application of the SPS is a dynamic and complex process due to the diversity of actors involved and the heterogeneity of objectives pursued: political, social, economic and environmental. In this global scenario,...

  7. Logística esbelta aplicada al transporte en el sector minero

    OpenAIRE

    2009-01-01

    Este trabajo  ha sido elaborado con el objetivo de plantear la logística esbelta como una de las soluciones actuales como factor de competitividad y reducción de costos en las empresas del sector minero. Aquí se expresa la necesidad de que las  redes de transporte tengan opciones de mejorar su gestión logística manejando sus recursos de manera adecuada, reduciendo costos y usando herramientas de nueva generación, de modo que mejore sustancialmente su estrategia competitiva, con el fin de logr...

  8. La neurociencia aplicada al estudio del género: ¿una nueva perspectiva?

    OpenAIRE

    Pallarés Domínguez, Daniel Vicente

    2011-01-01

    Setzenes Jornades de Foment de la Investigació (Any 2011) La neurociencia es a día de hoy una ciencia experimental que va conformando su sentido y modificando las disciplinas en las que influye. Como método científico utiliza todas las herramientas posibles para explicar el funcionamiento cerebral humano sobre todo, y lo estudia desde el parámetro de los estímulos y reacciones innatas con los que crea circuitos neuronales, ayudando a los seres humanos a tomar decisiones...

  9. La praxeología motriz aplicada al fútbol

    OpenAIRE

    Martínez de Santos Gorostiaga, Raúl

    2014-01-01

    XX,560 p. La praxeología motriz ha sido en marco conceptual empleado para el estudio de tres aspectos del fútbol especialmente relevantes: su relación con la acción humana, la naturaleza de su competencia experta y el proceso de formación del futbolista de élite. Cada uno de estos aspectos es analizado en profundidad y por separado llegándose a las siguientes conclusiones: - el fútbol es un ámbito óptico-práctico de competición motriz creado mediante reglas cuyo contenido da lugar a un ...

  10. Técnicas de auto escalado de cloud computing aplicadas al esteganoanálisis

    OpenAIRE

    San Aniceto Orbegozo, Iñigo

    2011-01-01

    En este Proyecto Final de Máster se estudia un sistema de esteganografía y un algoritmo de esteganoanálisis para romper este sistema. Tras desarrollar el algoritmo de esteganoanálisis, este se adapta para poder ejecutarse en una arquitectura de cloud computing auto-escalable y se estudian las ventajas de romper así el sistema de esteganografiado. [ABSTRACT] In this Master Thesis, a steganography system is analysed and, an algorithm to broke the system is presented. After developing the ...

  11. Herramientas moleculares aplicadas al estudio de aguas para el consumo humano, comunidad El Cacao, Nicaragua

    Directory of Open Access Journals (Sweden)

    Leandro A. Paramo

    2017-03-01

    Full Text Available Se determinó la presencia de contaminantes microbianos en aguas de consumo humano de la comunidad El Cacao, Mosonte, Nueva Segovia. El análisis se realizó tanto por métodos microbiológicos como por vía molecular analizando su interrelación con las enfermedades que se observan en la comunidad. Se obtuvo la presencia de coliformes fecales, totales y Escherichia coli desde la captación hasta el tanque de almacenamiento. Los aislados identificados pertenecen a las bacterias del tipo Alcaligenes y Paenalcaligenes, además de Stenotrophomonas y Serratia. Las cuales son bacterias acuáticas y están asociadas a diversas enfermedades. Además se identificó lapresencia de Aspergillus que han sido bien reportados en diversas enfermedades humanas.

  12. Effect of Cr and Al substitution cations on the structural and magnetic properties of Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} nanoparticles synthesized using the sol–gel auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Ekhlasi, Sima; Mousavinia, Mohammad

    2014-03-15

    The Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} (x=0–0.5) nanoparticles were prepared by employing the sol–gel auto-combustion method. The effect of aluminum and chromium on the structural and superparamagnetic properties of prepared samples was investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy, vibrating sample magnetometry (VSM), ac magnetic susceptibility and magnetization temperature curve recording in ZFC mode analysis. The XRD analysis of all synthesized samples confirmed the formation of single-phase cubic spinel structure. The results of FTIR analysis indicated that the functional groups of Ni–Zn spinel ferrite were formed during the auto-combustion sol–gel process. Moreover, FE-SEM and TEM micrographs demonstrated that nanoparticles with narrow size distribution were obtained. According to VSM results by increasing substitution contents, saturation magnetization decreased. Magnetic dynamics of the samples was studied by measuring ac magnetic susceptibility versus temperature at different frequencies. The phenomenological Néel–Brown and Vogel–Fulcher models were employed to distinguish between the interacting or noninteracting system. Results exhibited that there is a strong interaction between nanoparticles. A frequency–dependence peak was observed in ac magnetic susceptibility versus temperature for nanoparticles which is well fitted by the Vogel–Fulcher model. It is confirmed that there is strong magnetic interaction among prepared nanoparticles. - Highlights: • The hysteresis curves of the Ni{sub 0.6}Zn{sub 0.4}Fe{sub 2−x}Cr{sub x/2}Al{sub x/2}O{sub 4} nanoparticles exhibited the reduction of saturation magnetization with an increase in substitution value. • The good agreement between the susceptibility data and the Vogel–Fulcher model confirms the existence of strong interactions

  13. LA INVESTIGACIÓN APLICADA: UNA FORMA DE CONOCER LAS REALIDADES CON EVIDENCIA CIENTÍFICA

    Directory of Open Access Journals (Sweden)

    Zoila Rosa Vargas Cordero

    2009-01-01

    Full Text Available En este ensayo se expone una interpretación sobre la investigación aplicada vigente en el Sistema de Estudios de Posgrado de la Universidad de Costa Rica (SEP, para el trabajo final de graduación en las maestrías profesionales. Se discuten algunos criterios de la autora, discusiones académicas sobre el tema y otros razonamientos, con base en aportes de diferentes autores. Se fundamenta la necesidad de actualizar conocimientos acordes con la investigación y las posibilidades para realizarla, y se parte del supuesto de que la investigación es imprescindible en la formación profesional, ya que genera nuevos conocimientos que realimentan las disciplinas y el ejercicio profesional. La investigación requiere rigurosidad y excelencia; además, sostiene la plataforma para proponer y desarrollar nuevas investigaciones. Por ello, no se puede ignorar la importancia de la participación activa de estudiantes y docentes en los procesos de investigación, para favorecer la toma de conciencia de la realidad que se investiga, así como de los deberes y derechos de quienes investigan, lo que implica una nueva forma de pensar la práctica investigativa, de manera que se ofrezcan soluciones en función de los contextos, las acciones de las personas y los cambios filosóficos, ontológicos, epistemológicos y metodológicos en investigación. Al respecto, la investigación basada en el conocimiento y la comprensión de cómo perciben las personas su realidad y a sí mismas; es decir, aquella que se enfoca en el desarrollo de acciones para el mejoramiento de la realidad que se investiga es vista a lo largo del ensayo como una necesidad operativa.

  14. Postguerra y contracultura. Identidades en la ética aplicada

    Directory of Open Access Journals (Sweden)

    López de la Vieja de la Torre, M. Teresa

    2006-12-01

    Full Text Available The article analyses the role of cultural identities in Applied Ethics. Biotechnologies have been actually valued from different perspectives in Europe and in the United States. Since Nazi research and the politics of racial hygiene have shown the role of science under dictatorship. Nazi Doctors acted as soldiers. Therefore The Nürnberg Code claimed respect for human rights in Medicine, to protect individuals in clinical research. However American Doctors considered the Code suitable for a different context. Norms for a “barbaric” research, far away from the American standards. But in the United States radiations experiments have ignored laws and moral standards. Decades later, the Constitutional Treaty for the European Union emphasizes the value of dignity and personal integrity in the fields of Medicine and Biology. The informed consent and the prohibition of Eugenics connect then the future and the past.El artículo analiza el papel de las identidades culturales en la Ética aplicada. Las biotecnologías han sido valoradas efectivamente desde distintas perspectivas, en Europa y en Estados Unidos. Pues la investigación y la política de higiene racial durante el Nacionalsocialismo mostraron el papel desempeñado por la ciencia en la dictadura. Los médicos nazis actuaron como soldados. Por ello, el Código de Nürnberg reclamó respecto por los derechos humanos en Medicina, a fin de proteger a los ciudadanos en la investigación. Los médicos norteamericanos consideraron que el Código era adecuado para otro contexto, sin embargo. Normas para una investigación “bárbara”, alejada de los estándares americanos. Pero en Estados Unidos los experimentos con radiación ignoraron leyes y estándares morales. Décadas mas tarde, el Tratado constitucional para la Unión Europea insiste en el valor de la dignidad y de la integridad personal en Medicina y Biología. El consentimiento informado y la prohibición de practicas eugen

  15. 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.

  16. Synthesis of a novel Pd/Al2O3 catalyst for Ventilation Air Methane combustion with excellent catalytic activity in low temperatures%煤矿乏风甲烷氧化新型Pd/Al2O3催化剂的合成

    Institute of Scientific and Technical Information of China (English)

    刘文革; 郭德勇; 徐鑫

    2012-01-01

    运用溶胶-凝胶法合成了同时具有介孔和三维交联通透型微米级大孔的Al2O3多孔材料,并以其为载体采用浸渍法制备得到一种新型的Pd/Al2O3整体式催化剂,考察了不同助剂Ce,Zr,La及不同的助剂负载量对甲烷催化燃烧活性的影响.实验结果表明,所合成的新型Pd/Al2O3催化剂具有良好的低温活性,在CH4体积百分数为1%,反应气体空速为6 000 h-1的实验条件下,Pd/Al2O3的起燃温度只有227 ℃,认为这主要是采用的Al2O3载体材料中存在的三维交联通透型微米级大孔骨架可以提供快速的传质通道,在骨架中存在的纳米级介孔能提供较大的表面积和单位容量,从而有利于提高活性组分的分散性及有效利用效率,提高催化剂的活性.助剂Zr的加入能够降低催化剂的起燃温度,而助剂Ce对催化剂活性的影响与其添加量有关.%Bimodal A12O3 porous material with both mesopores and three-dimensional interconnected macropores in micrometer-scale was synthesized via sol-gel method. A kind of novel Pd/Al2O3 monolithic catalysts were prepared by impregnation using the as-synthesized A12O3 porous material as the support. Influence of different additives of Ce,Zr, La and different load amount of the additives on methane combustion activity were investigated. The experimental results show that the new synthesized Pd/Al2O3 catalyst has good low temperature activity. Under the experimental conditions of 1%CH4 with reaction gas space velocity of 6 000 h"1 ,the ignition temperature of Pd/Al2O3 is only 227 t. It is considered that the three-dimensional interconnected macropores of A12O3 support can provide fast mass transfer channel;while the nanoscale mesopores in the skeleton can provide large surface area and unit volume,and thus help to increase the catalytic activity by improving the dispersion of the active component and use efficiency. Additives of Zr can reduce the ignition temperature of the catalyst; the

  17. Combustion Enhancement with a Silent Discharge Plasma

    Science.gov (United States)

    Rosocha, Louis

    2003-10-01

    It is well known that the application of an external electric field to a flame can affect its propagation speed, stability, and combustion chemistry (Lawton & Weinberg 1969). External electrodes, arc discharges, and plasma jets have been employed to allow combustible gas mixtures to operate outside their flammability limits by gas heating, injection of free radicals, and field-promoted flame stabilization (Yagodnikov & Voronetskii 1994). Other investigators have carried out experiments with silent electrical discharges applied to propagating flames (Inomata et al 1983, Kim et al 2003). These have demonstrated that the flame propagation velocity is actually decreased (combustion retarded) when a silent discharge is applied directly to the flame region, but that the flame propagation velocity is increased (combustion promoted) when a silent discharge is applied to the unburned gas mixture upstream of a flame. Two other recent works have considered the possibility of combustion enhancement in aircraft gas turbine engine combustor mixers by using a plasma-generating fuel nozzle, that employs an electric-arc or microwave plasma generator, to produce dissociated fuel or ionized fuel (Johnson et al 2001); and pulsed corona-enhanced detonation of fuel-air mixtures in jet engines (Wang et al 2003). In contrast to these prior works, we have employed a silent discharge plasma (SDP) reactor to break up large fuel molecules into smaller molecules and create free radicals or other active species in a gas stream before the fuel is mixed with an oxidizer and combusted. In experiments reported here, a cylindrical SDP reactor was used to 'activate' propane before mixing it with air and igniting the combustible gas mixture. With the plasma, the physical appearance of the flame changes and substantial changes in mass spectrometer fragmentation peaks are observed (e.g., propane fragments decrease and water and carbon dioxide increase). This indicates that the combustion process is

  18. Factors Influencing Temperature Fields during Combustion Reactions

    Science.gov (United States)

    2014-05-20

    PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORTDATE(DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) New Reprint - 4. TITLE AND...Aluminum Rich Al-Ti Mechanical Alloys in Air, Combust. Flame 2006, 144, 688. [27] Z. Zhang, B. Tsai, G. Machin, Radiometric Temperature Measure- ments

  19. Website: material de apoio para professores de biofísica aplicada a enfermagem

    OpenAIRE

    Guimarães,Fábio Sander Prado; Dickman,Adriana Gomes; Chaves, Andréa Carla Leite

    2014-01-01

    Esse trabalho relata o processo de elaboração de um website relacionando a física com a biologia com o objetivo de instrumentalizar o professor para o ensino de biofísica aplicada ao curso de enfermagem. O material inclui compilações de textos, exercícios, vídeos, animações, situações problematizadoras e artigos científicos sobre biofísica aplicada à enfermagem. Os temas abordados foram definidos a partir de uma pesquisa realizada junto a enfermeiros, professores e alunos do curso de enfermag...

  20. 惰性载体Al_2O_3对Fe_2O_3及CuO氧载体煤化学链燃烧的影响%Effect of Inert Support Al_2O_3 on the Chemical Looping Combustion of Coal With Fe_2O_3 and CuO-based Oxygen Carrier

    Institute of Scientific and Technical Information of China (English)

    王保文; 赵海波; 郑瑛; 柳朝晖; 郑楚光; 晏蓉

    2011-01-01

    氧载体是煤化学链燃烧技术的基础,惰性载体则是其中的必要组成部分,起着重要的作用。以Al2O3作为典型惰性载体,采用热重分析仪、红外频谱仪、场发射扫描电镜和能谱分析仪以及X衍射仪,对六盘水贫煤与Fe2O3、CuO基氧载体的反应进行了详细的研究。研究发现,Al2O3的引入,使得Fe2O3、CuO基氧载体表面积增大、孔径分布更为优化,而且对氧载体与六盘水贫煤一次热解产物的反应是有利的,能够促进氧载体中更多晶格氧的传递,Fe2O3基氧载体中有更多的Fe2O3还原为低于Fe3O4价态的氧化物,而CuO基氧载体中CuO除了还原为Cu、Cu2O外,其中的CuAl2O4也有一定的反应活性,被还原为CuAlO2。与LPS煤反应时,Fe2O3深度还原产物与部分Al2O3及煤中的SiO2反应生成Fe3Al2(SiO4)3,而CuO则与Al2O3及六盘水贫煤反应生成了(Cu0.215Mg1.785)(Al4Si5O18)复合物。%Oxygen carrier(OC) is the basis for chemical looping combustion of coal and inert support is the necessary part of OC.Al2O3 was adopted as the typical inert support and the reaction of Liupanshui(LPS) coal with Fe2O3,CuO based OC was systematically investigated by various experimental means,including thermogravimetric analysis(TGA),Fourier transform infrared spectroscopy(FTIR),field scanning electron microscopy coupled with energy-dispersive X-ray spectrometry(FSEM-EDX) and X-ray diffraction(XRD) analysis.It was found that,the introduction of Al2O3 to Fe2O3 and CuO made the surface areas of these two OC greatly increased and the pore distribution more optimized,which benefited the primary gaseous products of LPS coal to react with Fe2O3 and CuO.Furthermore,during the reaction of LPS with these two OC,the optimized pore size distribution promoted more sufficient reaction of LPS coal with Fe2O3,and thus more Fe2O3 was reduced into lower valence oxides than Fe3O4;but for CuO based OC,their solid reduced products with

  1. Progressive combustion in SI-Engines—Experimental investigation on influence of combustion related parameters

    Indian Academy of Sciences (India)

    R Harish Kumar; A J Antony

    2008-12-01

    The fuel heat release rate which virtually controls the combustion process is dependent on the ‘Mass-Fraction-Burnt (MFB)’. In the present research work, a ‘logistic model with conditional variability in MFB’, has been developed for precise simulation of combustion in SI engines as the model has built in routines to take into account such factors as location of spark plug, single/dual spark plugs, intake generated swirl, combustion chamber geometry (associated with Bore/Stroke ratio), etc. A major contribution of this paper is that new and improved models for the ‘overall combustion duration’, and ‘ignition delay/flame development angle’, taking into account primarily the influence of compression ratio on the overall combustion process in SI engine have been developed. Taylor’s original equation for estimating the overall combustion duration has been modified by including a logistic equation for the error term and incorporating it in the original equation. Ignition delay as proposed by Keck et al has been modified by incorporating a polynomial of 3rd order into the original equation. The empirical correlations that have been proposed in this paper may serve to be the starting point for simulation of ‘photodetonation concept’ to simulate HCCI combustion which is presently the hot research work in the area of pre-mixed combustion. A program in Turbo-C++ has been developed for the complete simulation of SI engine combustion, taking into account the conditional variability effect, variable specific heats of burnt gases, dissociation of gases at high temperatures, progressive combustion phenomena, heat transfer (based on Woschni‘s equation), gas exchange process based on 1D-steady gas flow equation employing Taylor’s mach index of 0·6 for valve design.

  2. Coal combustion products

    Science.gov (United States)

    Kalyoncu, R.S.; Olson, D.W.

    2001-01-01

    Coal-burning powerplants, which supply more than half of U.S. electricity, also generate coal combustion products, which can be both a resource and a disposal problem. The U.S. Geological Survey collaborates with the American Coal Ash Association in preparing its annual report on coal combustion products. This Fact Sheet answers questions about present and potential uses of coal combustion products.

  3. Design factors for stable lean premix combustion

    Energy Technology Data Exchange (ETDEWEB)

    Richards, G.A.; Yip, M.J.; Gemmen, R.S.

    1995-10-01

    The Advanced Turbine Systems (ATS) program includes the development of low-emission combustors. Low emissions have already been achieved by premixing fuel and air to avoid the hot gas pockets produced by nozzles without premixing. While the advantages of premixed combustion have been widely recognized, turbine developers using premixed nozzles have experienced repeated problems with combustion oscillations. Left uncontrolled, these oscillations can lead to pressure fluctuations capable of damaging engine hardware. Elimination of such oscillations is often difficult and time consuming - particularly when oscillations are discovered in the last stages of engine development. To address this issue, METC is studying oscillating combustion from lean premixing fuel nozzles. These tests are providing generic information on the mechanisms that contribute to oscillating behavior in gas turbines. METC is also investigating the use of so-called {open_quotes}active{close_quotes} control of combustion oscillations. This technique periodically injects fuel pulses into the combustor to disrupt the oscillating behavior. Recent results on active combustion control are presented in Gemmen et al. (1995) and Richards et al. (1995). This paper describes the status of METC efforts to avoid oscillations through simple design changes.

  4. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  5. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  6. Research Combustion Laboratory (RCL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Research Combustion Laboratory (RCL) develops aerospace propulsion technology by performing tests on propulsion components and materials. Altitudes up to 137,000...

  7. Development and Validation of a Reduced DME Mechanism Applicable to Various Combustion Modes in Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Gregory T. Chin

    2011-01-01

    Full Text Available A 28-species reduced chemistry mechanism for Dimethyl Ether (DME combustion is developed on the basis of a recent detailed mechanism by Zhao et al. (2008. The construction of reduced chemistry was carried out with automatic algorithms incorporating newly developed strategies. The performance of the reduced mechanism is assessed over a wide range of combustion conditions anticipated to occur in future advanced piston internal combustion engines, such as HCCI, SAHCCI, and PCCI. Overall, the reduced chemistry gives results in good agreement with those from the detailed mechanism for all the combustion modes tested. While the detailed mechanism by Zhao et al. (2008 shows reasonable agreement with the shock tube autoignition delay data, the detailed mechanism requires further improvement in order to better predict HCCI combustion under engine conditions.

  8. Combustion Characteristics of Coated Nano Aluminum in Composite Propellants

    Directory of Open Access Journals (Sweden)

    Yunlan Sun

    2006-10-01

    Full Text Available The effects of coated nano-sized aluminum (Al powder (n-Al and micron-sized Al powder(g-Al in propellants on the burning rate and pressure exponent have been investigated. Theresults show that the burning rates of propellants increase as the n-Al content increases, butthe burning rate pressure exponents tend to decrease. Compared with propellant containing-Al, the increments of burning rates of propellants containing n-Al powder reduce graduallywith increase in the pressure because of the differences of the combustion characteristics andignition performances of n-Al powder and g-Al powder. Single short distance photograph, scanningelectron microscopy, x-ray fluorescence analysis were used to characterise the flame image,combustion phenomena, the quenched surface image, and surface elements. A substantialdifference in combustion characteristics of n-Al powder has been found in comparison with-Al powder. In addition, oxygen-bomb combustion heat, ignition temperature, and recoveryratio of residues were measured.

  9. Los cambios en la productividad: medidas alternativas aplicadas a Colombia

    OpenAIRE

    Botero García, Jesús

    2005-01-01

    Desde el seminal artículo de Solow (1957), la productividad ha sido un tema recurrente en la literatura económica. La forma elegante como dicho artículo torna aprehensible un concepto de otra manera difuso, ha alentado numerosas investigaciones y ha propiciado esfuerzos conducentes a hacer más precisa su medición. El presente artículo pretende revisar esas mediciones alternativas y aplicarlas al caso Colombiano, al tiempo que interpreta la relación entre el concepto de productividad tal y com...

  10. Dimensão aplicada na análise do comportamento

    Directory of Open Access Journals (Sweden)

    Canaan-Oliveira Silvia

    2003-01-01

    Full Text Available O presente estudo teve como objetivo examinar a lógica do uso do termo "aplicada" na Análise do Comportamento a partir de elementos identificados na literatura desta área e na linguagem cotidiana. As concepções de aplicação encontradas foram categorizadas em três grupos: a aplicação enquanto prestação de serviço que leva a discussão para o continuum prestação de serviço X pesquisa, assemelhando-se à forma como o termo "aplicada" é utilizado na linguagem cotidiana, b aplicação enquanto uma forma de pesquisa que revela uma revisão do conceito de aplicação na linguagem cotidiana e sua estensão para atividades científicas, direcionando a discussão para o continuum pesquisa básica x pesquisa aplicada e c aplicação enquanto atividade simultânea de pesquisa e prestação de serviço que sinaliza o caráter complementar destas atividades. Portanto, existem tradições coexistentes na Análise do Comportamento que apoiam diferentes usos do termo "aplicada".

  11. 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 beginni

  12. Strobes: An Oscillatory Combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; van Lingen, J.N.J.; 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 beginni

  13. Lectures on combustion theory

    Energy Technology Data Exchange (ETDEWEB)

    Burstein, S.Z.; Lax, P.D.; Sod, G.A. (eds.)

    1978-09-01

    Eleven lectures are presented on mathematical aspects of combustion: fluid dynamics, deflagrations and detonations, chemical kinetics, gas flows, combustion instability, flame spread above solids, spark ignition engines, burning rate of coal particles and hydrocarbon oxidation. Separate abstracts were prepared for three of the lectures. (DLC)

  14. Fifteenth combustion research conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-06-01

    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.

  15. Coal Combustion Science

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. (ed.); Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. (Sandia National Labs., Livermore, CA (United States))

    1991-08-01

    The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

  16. Combustion of coffee husks

    Energy Technology Data Exchange (ETDEWEB)

    Saenger, M.; Hartge, E.-U.; Werther, J. [Technical Univ. Hamburg-Harburg, Chemical Engineering 1, Hamburg (Germany); Ogada, T.; Siagi, Z. [Moi Univ., Dept. of Production Engineering, Eldoret (Kenya)

    2001-05-01

    Combustion mechanisms of two types of coffee husks have been studied using single particle combustion techniques as well as combustion in a pilot-scale fluidized bed facility (FBC), 150 mm in diameter and 9 m high. Through measurements of weight-loss and particle temperatures, the processes of drying, devolatilization and combustion of coffee husks were studied. Axial temperature profiles in the FBC were also measured during stationary combustion conditions to analyse the location of volatile release and combustion as a function of fuel feeding mode. Finally the problems of ash sintering were analysed. The results showed that devolatilization of coffee husks (65-72% volatile matter, raw mass) starts at a low temperature range of 170-200degC and takes place rapidly. During fuel feeding using a non water-cooled system, pyrolysis of the husks took place in the feeder tube leading to blockage and non-uniform fuel flow. Measurements of axial temperature profiles showed that during under-bed feeding, the bed and freeboard temperatures were more or less the same, whereas for over-bed feeding, freeboard temperatures were much higher, indicating significant combustion of the volatiles in the freeboard. A major problem observed during the combustion of coffee husks was ash sintering and bed agglomeration. This is due to the low melting temperature of the ash, which is attributed to the high contents of K{sub 2}O (36-38%) of the coffee husks. (Author)

  17. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, M.J.; Hoagland, M.C.; Hubbard, R.L.; Schaub, F.S.

    1981-12-22

    A method of combusting natural gas fuel in a two cycle, turbocharged internal combustion engine substantially reduces the production of nitrogen-oxygen emissions. An improved turbocharger design provides increased air charging pressure, produces a controlled lean air/fuel mixture and lowers peak combustion temperatures. A jet cell ignition device ensures uniform, reliable ignition of the lean air/fuel mixture under all operating conditions and the lean air/fuel mixture in turn encourages complete fuel combustion and provides excellent combustion characteristics with methane, ethane and heavier paraffinic hydrocarbon fuels. These structural modifications and adjustment of other operating parameters combine to reduce nitric oxide (NO) and nitrogen dioxide (NO/sub 2/) emissions by as much as 75% while effecting only a negligible increase in fuel consumption.

  18. 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.

  19. Combustion and Plasma Synthesis of High-Temperature Materials

    Science.gov (United States)

    Munir, Z. A.; Holt, J. B.

    1997-04-01

    KEYNOTE ADDRESS. Self-Propagating High-Temperature Synthesis: Twenty Years of Search and Findings (A. Merzhanov). SOLID-STATE COMBUSTION SYNTHESIS. Recent Progress in Combustion Synthesis of High-Performance Materials in Japan (M. Koizumi & Y. Miyamoto). Modeling and Numerical Computation of a Nonsteady SHS Process (A. Bayliss & B. Matkowsky). New Models of Quasiperiodic Burning in Combustion Synthesis (S. Margolis, et al.). Modeling of SHS Operations (V. Hlavacek, et al.). Combustion Theory for Sandwiches of Alloyable Materials (R. Armstrong & M. Koszykowski). Observations on the Combustion Reaction Between Thin Foils of Ni and Al (U. Anselmi-Tamburini & Z. Munir). Combustion Synthesis of Intermetallic Compounds (Y. Kaieda, et al.). Combustion Synthesis of Nickel Aluminides (B. Rabin, et al.). Self-Propagating High-Temperature Synthesis of NiTi Intermetallics (H. Yi & J. Moore). Shock-Induced Chemical Synthesis of Intermetallic Compounds (S. Work, et al.). Advanced Ceramics Via SHS (T. DeAngelis & D. Weiss). In-Situ Formation of SiC and SiC-C Blocked Solids by Self-Combustion Synthesis (S. Ikeda, et al.). Powder Purity and Morphology Effects in Combustion-Synthesis Reactions (L. Kecskes, et al.). Simultaneous Synthesis and Densification of Ceramic Components Under Gas Pressure by SHS (Y. Miyamoto & M. Koizumi). The Use of Self-Propagating High-Temperature Synthesis of High-Density Titanium Diboride (P. Zavitsanos, et al.). Metal--Ceramic Composite Pipes Produced by a Centrifugal-Thermit Process (O. Odawara). Simultaneous Combustion Synthesis and Densification of AIN (S. Dunmead, et al.). Fabrication of a Functionally Gradient Material by Using a Self-Propagating Reaction Process (N. Sata, et al.). Combustion Synthesis of Oxide-Carbide Composites (L. Wang, et al.). Heterogeneous Reaction Mechanisms in the Si-C System Under Conditions of Solid Combustion (R. Pampuch, et al.). Experimental Modeling of Particle-Particle Interactions During SHS of TiB2 -Al2O3 (K. Logan

  20. Minería de datos aplicada en detección de intrusos

    Directory of Open Access Journals (Sweden)

    Diego Vallejo P.

    2012-06-01

    Full Text Available Con base a los fundamentos y técnicas de la minería de datos se pueden diseñar y elaborar modelos que permiten encontrar comportamientos clandestinos de fácil detección a simple vista como lo es la información no evidente -desconocida a priori y potencialmente útil- en referencia a hechos determinados. En particular la utilidad de la minería de datos en esta área radica en una serie de técnicas, algoritmos y métodos que imitan la característica humana del aprendizaje: ser capaz de extraer nuevos conocimientos a partir de las experiencias. La minería de datos posee características como: análisis de grandes volúmenes de información, generación de comportamientos que no son fácilmente perceptibles, depuración de datos para toma de decisiones. Estas características pueden ser de vital importancia para ser aplicadas en la seguridad de la información a través de la detección de intrusos. En la actualidad la seguridad de la información es uno de los grandes retos que tiene el mundo, y en especial, la detección de anomalías en los registros de acceso de los diferentes sistemas de información. Con esta aplicabilidad resulta un método básico y muy eficiente de poder prevenir intrusiones. Se centra el campo de en la detección de intrusos al nutrir el proceso de seguimiento de los acontecimientos que ocurren en la red informática, seguido del análisis de los mismos; con el fin de detectar los factores que ponen en peligro la confidencialidad, integridad, disponibilidad y no repudio de los datos. En el presente trabajo se pretende mostrar el aporte a la seguridad de la información de la minería de datos en el contexto de la detección de intrusos.

  1. Structure and Luminescent Properties of Y3Al5O12:Eu3+ Nano-phosphor by Gel Combustion Synthesis%凝胶-燃烧法合成YAG:Eu3+纳米荧光材料的结构和发光性能

    Institute of Scientific and Technical Information of China (English)

    夏国栋; 周圣明; 张俊计; 张涟翰; 贾广强; 徐军

    2005-01-01

    Y3Al5O12:Eu nanophosphors were synthesized by a gel combustion method. The structure of phosphors was characterized by XRD and FTIR. YAG phase came to occur when YAG:Eu precursors were sintered at 800 ℃, although the phase was mainly amorphous. The organic groups pyrolyzed completely and pure YAG phase was obtained in the samples sintered at 900 ℃. In the formation of YAG phase, no intermediate phases such as YAP and YAM were detected. Both 5D0 → 7F1 orange and 5D0 → 7F2 red emission could be observed for all the sintered samples. However, the emission of amorphous samples was greatly different from that of crystalline ones. The former was mainly 5D0 → 7F2 red emission, but the latter was 5D0 → 7F1 orange emission. As sintering temperature rises, the ratio of orange to red for phosphors increases. Eu could be doped up to 8% in YAG host lattice, and fluorescence quenching was absent. It indicated that the gel combustion synthesis method can increase emission intensity and quenching concentration due to a good distribution of Eu3+ activators in Y3Al5O12 matrix.

  2. Valorisation du biogaz de fermentation : combustion catalytique

    OpenAIRE

    Dupont, Nicolas

    2010-01-01

    The objective of this work concerns the study of two classes of catalysts, mixed oxides (CuO/Al2O3, CuO-CuAl2O4, CuO-CuCr2O4, CuO-ZnO-Al2O3 undoped or doped with Ag and Mn) and nobles supported metals (Pd/Al2O3 and Pt/ Al2O3, Pd-Pt /Al2O3 undoped or doped with B) used in two different reactions: low temperature gas phase ammonia oxidation into nitrogen and high temperature methane catalytic combustion for energy production. Biogas, a renewable energy, is mainly constituted of methane and carb...

  3. Novas tecnologias aplicadas às embalagens de alimentos

    OpenAIRE

    Flávia De Floriani Pozza Rebello

    2009-01-01

    Com o desenvolvimento da indústria de alimentos, as embalagens têm se aperfeiçoado, indo além de sua função básica de proteger o alimento contra danos mecânicos e contaminações químicas e microbiológicas. Elas têm cada vez mais desempenhando papel de destaque, contribuindo ativamente para a venda de um produto. Assim, as indústrias de embalagens têm procurado atender aos consumidores mais exigentes e juntamente aos centros de pesquisa e universidades, têm investido mais em estudos de novas te...

  4. 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.

  5. Predicción Teórica del Consumo de Potencia y de la Tasa Promedia de Cortante Aplicada en el Desmucilaginado Mecánico del Café

    Directory of Open Access Journals (Sweden)

    Oliverost Carlos E.

    1995-09-01

    Full Text Available Se evaluó el desempeño de un desmucilaginador mecánico desarrollado en el Centro Nacional de Investigaciones del Café CENICAFE. Se obtuvo modelos teóricos para estimar consumo de potencia y la tasa promedia de cortante aplicada (“average shear rate” durante el proceso de desmucilaginado en un prototipo desarrollado en CENICAFE (denominado modelo RMM-CENICAFE B. El campo de flujo generado por las barras rotatorias del desmucilaginador fué asumido equivalente al originado por discos sumergidos en un medio fluido infinito. Se utilizó el enfoque fundamental propuesto por Karman (1921 para resolver la ecuación de Nauier-Stokes. Debido a la alta tasa de deformación aplicada por el agitador y a la naturaleza pseudoplástica de la suspension (Oliveros, 1993 se asumió que ésta se comporta como un fluido Newtoniano. Valores de viscosidad aparente en el segundo “plateau” Newtoniano fueron obtenidos para cada tratamiento. Los modelos teóricos obtenidos predicen bien el consumo de potencia y la tasa promedia de cortante aplicada.

  6. Estadística aplicada en el control de calidad

    Directory of Open Access Journals (Sweden)

    Ernesto Córdoba

    2011-11-01

    Full Text Available En el presente artículo se ilustra el desarrollo de diversos métodos estadísticos para orientar el Control de Calidad en la metalmecánica hacia una fundamentación más científica que permita regular el proceso de fabricación de maquinaria en una forma más eficaz y racional. Se señala que el método pasivo, determinación de las curvas de distribución, es muy dispendioso y costoso y además se realiza después del proceso de fabricación.De igual manera se presta especial atención a la etapa más reciente y promisoria de los métodos estadísticos aplicados al Control de Calidad que consiste en la construcción de los diagramas puntuales y gráficas de precisión. Este nuevo enfoque posibilita hacer más coherente y efectivo el proceso de control en relación al rendimiento económico del proceso de fabricación. Este artículo es útil para los ingenieros y también tiene aplicación directa en la industria. 

  7. Tensión aplicada y exposición gradual en un caso de fobia a las inyecciones

    Directory of Open Access Journals (Sweden)

    José Pedro Espada Sánchez

    2004-01-01

    Full Text Available La fobia a las inyecciones es un subtipo de fobia específica caracterizada por respuestas de miedo intenso y por conductas de evitación ante la situación de recibir una inyección. En este trabajo se presenta el caso clínico de una mujer de 28 años que padecía de forma crónica este trastorno, sufriendo desmayos de forma recurrente. El tratamiento se desarrolló durante 6 sesiones semanales de una hora. Los objetivos del tratamiento se establecieron a partir de la hipótesis explicativa de la respuesta de ansiedad ante la sangre. La terapia se centró en enseñar a la paciente a controlar la frecuencia cardiaca y a identificar los síntomas previos al desvanecimiento. Se aplicó un programa multicomponente que combinaba la técnica de la tensión aplicada y estrategias cognitivo-conductuales para el control de la activación anticipatoria y el afrontamiento de la situación fóbica. Las técnicas empleadas fueron la exposición en imaginación enriquecida, exposición en vivo, afrontamiento simbólico, autoinstrucciones y respiración profunda. Se discuten los resultados de la intervención, que confirman la eficacia del programa aplicado.

  8. Técnicas quirúrgicas periodontales aplicadas a la implantología Periodontal surgical techniques applied to implantology

    Directory of Open Access Journals (Sweden)

    L Mateos

    2003-08-01

    Full Text Available La similitud morfológica y funcional existente entre los tejidos periimplantarios y los tejidos periodontales ha permitido adaptar técnicas de uso habitual en periodoncia al campo de la implantologia. El manejo de los tejidos periimplantarios de forma correcta buscando como objetivo el mejorar el entorno periimplantario, tanto con fines estéticos como para facilitar el correcto mantenimiento, es una práctica habitual hoy en día en la terapia implantológica. El objetivo de este artículo es revisar la bibliografía referente a estos conceptos y las dístintas técnicas quirúrgicas empleadas en la terapia periodontal que han sido aplicadas en implantologia.Both periodontal and periimplant tissues share morphological and functional characteristics. This allows adapting common used periodontal techniques to the implantology. Nowadays, it is a normal practice to manage the soft periimplant tissues in a correct way, in order to improve the periimplant environment. The aim of this article is to make a literature review of all these concepts as well as the application of some periodontal techniques to the field of the implantology.

  9. Improving combustion efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Bulsari, A.; Wemberg, A.; Multas, A. [Nonlinear Solutions Oy (Finland)

    2009-06-15

    The paper describes how nonlinear models are used to improve the efficiency of coal combustion while keeping NOx and other emissions under desired limits in the Naantali 2 boiler of Fortum Power and Heat Oy. 16 refs., 6 figs.

  10. Fluidized coal combustion

    Science.gov (United States)

    Moynihan, P. I.; Young, D. L.

    1979-01-01

    Fluidized-bed coal combustion process, in which pulverized coal and limestone are burned in presence of forced air, may lead to efficient, reliable boilers with low sulfur dioxide and nitrogen dioxide emissions.

  11. Modelling diesel combustion

    CERN Document Server

    Lakshminarayanan, P A; Shi, Yu; Reitz, Rolf D

    2010-01-01

    The underlying principles of combustion phenomena are presented here, providing the basis for quantitative evaluation. These phenomena - ignition delay, fuel air mixing, rate of release, etc. - are then modelled for greater understanding and applicability.

  12. TENORM: Coal Combustion Residuals

    Science.gov (United States)

    Burning coal in boilers to create steam for power generation and industrial applications produces a number of combustion residuals. Naturally radioactive materials that were in the coal mostly end up in fly ash, bottom ash and boiler slag.

  13. TOXIC SUBSTANCES FROM COAL COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    A KOLKER; AF SAROFIM; CL SENIOR; FE HUGGINS; GP HUFFMAN; I OLMEZ; J LIGHTY; JOL WENDT; JOSEPH J HELBLE; MR AMES; N YAP; R FINKELMAN; T PANAGIOTOU; W SEAMES

    1998-12-08

    carried out during August at the Advanced Photon Source (APS), the new synchrotron facility at Argonne National Laboratory, Chicago, IL. Further analysis of small-scale combustion experiments conducted at PSI in Phase I was completed this quarter. The results of these experiments for the first time suggest almost complete vaporization of certain trace elements (Se, Zn) from coal combustion in the flame zone, in accordance with theoretical equilibrium predictions. Other elements (As, Sb, Cr) appeared considerably less volatile and may react with constituents in the bulk ash at combustion temperatures. The combustion section of the University of Arizona's Downflow Combustor was completely rebuilt. The University of Utah worked on setting up EPA Method 26A to give the capability to measure chlorine in flue gas. The chlorine kinetic calculations performed as part of the Phase I program were found to have an error in the initial conditions. Therefore, the calculations were re-done this quarter with the correct starting conditions. Development of a quasi-empirical emissions model based on reported emissions of particulate matter from field measurements was continued this quarter. As a first step in developing the ToPEM, we developed a sub-model that calculates the evaporation of major elements (Na, K, Fe, Si, Al, Ca and Mg) from both inherent and extraneous minerals of coal. During this quarter, this sub-model was included into EMAF, which formed the ToPEM. Experimental data from the Phase I program were used to test and modify the sub-model and the ToPEM.

  14. Scramjet Combustion Processes

    Science.gov (United States)

    2010-09-01

    plan for these flights is as follows: Scramjet Combustion Processes RTO-EN-AVT-185 11 - 21 HyShot 5 – A Free-Flying Hypersonic Glider HyShot...5 will be a hypersonic glider designed to fly at Mach 8. It will separate from its rocket booster in space and perform controlled manoeuvres as it...RTO-EN-AVT-185 11 - 1 Scramjet Combustion Processes Michael Smart and Ray Stalker Centre for Hypersonics The University of Queensland

  15. Premios Nobel de Quimica y Filatelia. Parte III: polimeros, coloides, quimica aplicada, quimica inorganica y premios siglo XXI

    National Research Council Canada - National Science Library

    Martinez-Reina, Marlon; Amado-Gonzalez, Eliseo

    2014-01-01

    ...; y la parte II, quimica analitica, quimica organica, productos naturales y bioquimica. En los tres articulos se busca resaltar el valor pedagogico de la filatelia, aplicada a un tema en particular...

  16. Premios Nobel de Quimica y Filatelia. Parte III: polimeros, coloides, quimica aplicada, quimica inorganica y premios siglo XXI

    National Research Council Canada - National Science Library

    Martinez-Reina, Marlon; Amado-Gonzalez, Eliseo

    2014-01-01

    En Premios Nobel de Quimica y Filatelia, Parte III, se hace una revision de los sellos postales emitidos en diferentes paises para conmemorar los Premios Nobel en polimeros, coloides, quimica aplicada...

  17. Álgebra aplicada en el mundo de las telecomunicaciones

    Directory of Open Access Journals (Sweden)

    José Antonio Montero Morales

    2008-06-01

    Full Text Available En este documento se expone un ejercicio de modelización matemática que se propone a alumnos de ingeniería de telecomunicaciones durante el primer curso, en la asignatura de ´algebra lineal. Aunque la modelización matemática hace referencia generalmente a la construcción de modelos que ayudan a realizar predicciones o a explicar fenómenos complejos, en este caso debe interpretarse como una herramienta docente que permite llevar a la práctica con los estudiantes una actividad organizativa y estructurada mediante la cual se utilizan conocimientos previamente adquiridos para descubrir regularidades y relaciones en situaciones pertenecientes al mundo real.

  18. 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.

  19. METC Combustion Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Halow, J.S.; Maloney, D.J.; Richards, G.A.

    1993-11-01

    The objective of the Morgantown Energy Technology Center (METC) high pressure combustion facility is to provide a mid-scale facility for combustion and cleanup research to support DOE`s advanced gas turbine, pressurized, fluidized-bed combustion, and hot gas cleanup programs. The facility is intended to fill a gap between lab scale facilities typical of universities and large scale combustion/turbine test facilities typical of turbine manufacturers. The facility is now available to industry and university partners through cooperative programs with METC. High pressure combustion research is also important to other DOE programs. Integrated gasification combined cycle (IGCC) systems and second-generation, pressurized, fluidized-bed combustion (PFBC) systems use gas turbines/electric generators as primary power generators. The turbine combustors play an important role in achieving high efficiency and low emissions in these novel systems. These systems use a coal-derived fuel gas as fuel for the turbine combustor. The METC facility is designed to support coal fuel gas-fired combustors as well as the natural gas fired combustor used in the advanced turbine program.

  20. Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion

    Institute of Scientific and Technical Information of China (English)

    王锐; 罗雄麟; 许锋

    2014-01-01

    With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts:the air consumed by coke burning, the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking (FCC) unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

  1. COMBUSTION SYNTHFSIS AND DENSIFICATION BY GAS HOT ISOSTATIC PRESSURE OF AIN- TiB2 CERAMIC WITHOUT ENVELOPE%无包封燃烧合成气相热等静压AlN-TiB2陶瓷研究

    Institute of Scientific and Technical Information of China (English)

    郑永挺; 韩杰才; 赫晓东

    2001-01-01

    本文采用燃烧合成工艺,在100MPa氮气的气相热等静压作用下,制备了致密的AlN-TiB2系陶瓷,相对密度达95%,抗弯强度达350 MPa。研究表明,Al-N2-TiB2体系燃烧过程中,当反应温度升至660℃时Al熔化,1 000℃时Al开始剧烈挥发,与N2迅速反应形成AlN。在反应区高温下熔融Al在TiB2表面发生浸流现象,使Al的反应层厚度减小,反应面积增大,反应速度提高。同时Al的漫流使燃烧反应区发生液相烧结,从而使反应区孔隙率显著下降,当开气孔闭合时在气相压力作用下形成致密产物。随着TiB2含量增加,液相烧结作用增强,产物致密度提高。Al-N2-TiB2体系燃烧合成的致密化主要发生在燃烧波蔓延方向,具有明显的方向性。%Compact AlN/TiB2 ceramics was fabricated by combustion synthesis of Al particles in the super-high pressure nitrogen (100 MPa). Maximal relative density of 95% and maximal bending strength of 350 MPa are reached for the products. In the SHS process of Al-N2-TiB2 system, when the temperature is up to 660 ℃, metal Al melts and volatilizes strongly at 1 000 ℃. Al vapor vapidly reacts with N2 to form AlN. At high temperature melted Al spread over the TiB2 particle surface, which lead to a decrease of reaction layer thickness of melted Al, an increase of reaction surface and speed, and liquid sinter occurs.As a result, the porosity of the reaction zone decreases significantly. With increasing of TiB2 content in the original powder system, liquid sintering decreases, and the relative density, bending strength and fracture toughness of the products are increased. In Al- N2 - TiB2 system, SHS-densification has apparent tropism of mainly occurs along the combustion front.

  2. Análise da transformada em ondeletas aplicada em sinal geofísico

    OpenAIRE

    Bolzan,Maurício José Alves

    2004-01-01

    É mostrada uma análise em ondeletas aplicada em um sinal geofísico, número de manchas solares. Para isso, é dado uma introdução teórica sobre a Transformada em Ondeletas e sobre séries e Transformada de Fourier. A Transformada em Ondeletas é uma ferramenta matemática de grande utilidade aplicação em sinais não-estacionários.

  3. Combustion synthesis of bulk nanocrystalline iron alloys

    Directory of Open Access Journals (Sweden)

    Licai Fu

    2016-02-01

    Full Text Available The controlled synthesis of large-scale nanocrystalline metals and alloys with predefined architecture is in general a big challenge, and making full use of these materials in applications still requires greatly effort. The combustion synthesis technique has been successfully extended to prepare large-scale nanocrystalline metals and alloys, especially iron alloy, such as FeC, FeNi, FeCu, FeSi, FeB, FeAl, FeSiAl, FeSiB, and the microstructure can be designed. In this issue, recent progress on the synthesis of nanocrystalline metals and alloys prepared by combustion synthesis technique are reviewed. Then, the mechanical and tribological properties of these materials with microstructure control are discussed.

  4. Combustion synthesis of bulk nanocrystalline iron alloys

    Institute of Scientific and Technical Information of China (English)

    Licai Fu; Jun Yang; Weimin Liu

    2016-01-01

    The controlled synthesis of large-scale nanocrystalline metals and alloys with predefined architecture is in general a big challenge, and making full use of these materials in applications still requires greatly effort. The combustion synthesis technique has been successfully extended to prepare large-scale nanocrystalline metals and alloys, especially iron alloy, such as FeC, FeNi, FeCu, FeSi, FeB, FeAl, FeSiAl, FeSiB, and the microstructure can be designed. In this issue, recent progress on the synthesis of nanocrystalline metals and alloys prepared by combustion synthesis technique are reviewed. Then, the mechanical and tribological properties of these materials with microstructure control are discussed.

  5. Effect of Al-substitution on phase formation and magnetic properties of barium hexaferrite synthesized with sol-gel auto-combustion method%溶液凝胶自燃烧法制备的铝掺杂对钡铁氧体晶相和磁性能的影响

    Institute of Scientific and Technical Information of China (English)

    岳中岳; 钟敏建; 马洪良; 郭广磊

    2008-01-01

    Al-substituted barium ferrite powders were synthesized using the sol-gel auto-combustion method according to the molecular formula BaAlxFe12-xO19 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0). Compared with non-substituted barium ferrite annealing at 1000℃, the vibrating sample magnetometer (VSM) measurement manifested that the optimum magnetic properties formation temperature of Al-substituted barium ferrite was 1100℃. The data from X-ray diffractometer (XRD) showed that with increasing x, the lattice constants (a and c) decreased as well as the unit-cell volume Vcell. Magnetic measurement of non-substituted and Al-substituted powders annealed from 900℃ to 1200℃ exhibited that the maximum magnetization M (10 kOe), the remanent magnetization Mr and the coercivity Hc depended strongly on the chemical composition of powder as well as the annealing temperature. When annealing at 1100℃, BaAl0.5Fe11.5019 of high coercivity Hc (6584 Oe) was produced. Meanwhile, M (10 kOe) and Mr were 42.83emu/g and 25.65emu/g, respectively.

  6. 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

    achieved. [Espanol] La combustion de aceite combustible residual emite sustancias nocivas como particulas carbonaceas, oxidos de nitrogeno y trioxido de azufre, a niveles inadmisibles. Agua emulsionada en el combustible reduce sustancialmente dichas emisiones, lograndose ademas, en la mayoria de los casos, un ahorro neto en el consumo de combustible. Se muestran los efectos beneficos de quemar el aceite combustible residual en forma de emulsion, asi como el metodo para producir una emulsion adecuada. La tecnologia del combustible emulsionado ofrece una opcion de bajo costo para reducir la contaminacion atmosferica. La calidad del aceite combustible residual ha estado declinando durante las ultimas decadas debido: 1. Al aumento en la produccion de petroleos crudos pesados generalmente con mayor contenido de asfaltenos y de azufre. 2. A menor disponibilidad de residuos de la destilacion al vacio debido a su conversion a productos de mayor valor. 3. A procesos de conversion mas intensivos, como cracking catalitico, {sup v}isbreaking{sup ,} etc., que aumentan la concentracion de asfaltenos en los fondos, ocasionando problemas de inestabilidad. 4. Al aumento en el contenido de vanadio y de otros metales a medida que aumenta la concentracion de asfaltenos. El uso de aceite combustible emulsionado proporciona un medio eficaz y economico para reducir sustancialmente las emisiones nocivas a la atmosfera. La emulsion contiene particulas de agua de un diametro entre 2 y 20 micras, dispersadas uniformemente dentro del aceite combustible, en una proporcion generalmente enter 5 y 10%; ademas contiene un agente tensioactivo para asegurar una emulsion estable, capaz de resistir los esfuerzos cortantes del sistema de bombeo y distribucion. Cuando las gotas de aceite combustible atomizado llegan a la camara de combustion, el agua esmulsionada en ellas se convierte instantaneamente en vapor de alta presion, ocasionando una violenta atomizacion secundaria. El efecto de esta atomizacion

  7. TERMOGRAFIA MÉDICA INFRAVERMELHA APLICADA À MEDICINA DO ESPORTE

    Directory of Open Access Journals (Sweden)

    Ana Carolina Ramos e Côrte

    Full Text Available RESUMO A termografia médica infravermelha é um instrumento de análise não invasiva e não radioativa, capaz de analisar funções fisiológicas relacionadas com o controle da temperatura da pele. A termografia detecta a luz infravermelha emitida pelo corpo e visualiza mudanças de temperatura corporal relacionadas à alteração no fluxo sanguíneo. Não é um método que mostra anormalidades anatômicas, porém é capaz de mostrar mudanças fisiológicas. Existem várias aplicações da termografia no campo da medicina: desordens neurológicas, reumatológicas, musculares, doenças vasculares, patologias urológicas, ginecológicas, ortopédicas e na medicina esportiva. Para todas as áreas médicas, a termografia está estabelecida como uma medida que proporciona um mapeamento visual da distribuição da temperatura da pele. A termografia não deve ser usada como ferramenta diagnóstica única. Exames clínicos devem ser realizados para interpretação dos termogramas. Nas aplicações médicas, esta técnica proporciona, somente, uma imagem da distribuição da temperatura da pele; não é capaz de mostrar dados de uma superfície profunda do corpo, como é possível por outros exames de imagem. Entretanto, é um método não-invasivo e objetivo, além de seguro e inofensivo. Na medicina do esporte, o uso da termografia pode proporcionar melhores resultados aos atletas por ser um instrumento na identificação de riscos e na prevenção de lesões, além de ser uma importante ferramenta no acompanhamento do treinamento esportivo, a partir da avaliação da quantificação da carga de trabalho.

  8. Miniestaquia aplicada a espécies florestais.

    Directory of Open Access Journals (Sweden)

    Aurea Portes Ferriani

    2010-12-01

    Full Text Available A miniestaquia é uma técnica recente de propagação vegetativa cujo princípio é o aproveitamento do potencial juvenil dos propágulos para indução do enraizamento. Tendo em vista a necessidade de produção de mudas em larga escala para diversos fins, pode representar uma alternativa promissora para espécies lenhosas que manifestem dificuldade de enraizamento do material adulto ou cujas sementes representem fator limitante. Nesse sentido, este trabalho apresenta procedimentos e resultados de pesquisas desenvolvidas com gêneros amplamente utilizados na silvicultura clonal, como Eucalyptus e Pinus, além de outras espécies florestais com potencial para plantios comerciais e de recuperação de ecossistemas. Assim, buscou-se analisar as condições de implantação e manejo que contribuem para o desenvolvimento satisfatório das minicepas e miniestacas como incremento do processo. A introdução da miniestaquia apresenta vantagens relacionadas à redução da área de produção, diminuição do período de enraizamento e aclimatação, além da redução do uso de reguladores vegetais para indução do enraizamento. = Minicutting is a recent plant propagation technique using the juvenile potential from propagules to rooting induction. Due to the necessity of plant production in large scale for different purposes, this method can present a promising alternative for woody species whose seeds are the limiting factor or express difficult to root the mature material. This study presents procedures and results of evaluations done with genus of plants frequently used in clonal forestry, such as Eucalyptusand Pinus, and other species with potential to new crops development in environmental restoration.Consequently,we analyzed the established conditions that contribute satisfactorily to the development of ministumps and minicuttings in an attempt to improve the process. The introduction of minicutting technique presents advantage related to the

  9. REDES TECNOLÓGICAS APLICADAS EM EaD

    Directory of Open Access Journals (Sweden)

    Suélly Lima dos Santos

    2011-08-01

    Full Text Available Com o advento da internet e o aparecimento das novas tecnologias educacionais, conjunto de informações e comunicações (telefone, internet, rádio, vídeo, computador e televisão, ultrapassaram as fronteiras das quatro paredes da sala de aula, surgindo ambientes virtuais direcionadas à ampliação da participação dos serviços públicos relacionados ao ensino. À educação e à formação técnica e profissional permitiu-se o aumento da interatividade através da tecnologia, promovendo maneiras de acesso ao aluno utilizando computadores e/ou dispositivos móveis que viabiliza a Educação à Distância (EaD. Devido o grande crescimento do ensino à distância, as instituições já utilizam redes de dados para ampliar o acesso de aprendizagem. Com este espantoso aumento das redes, e da acelerada transmissão de informações aprender como elas funcionam é muito importante, além do mais usando a própria tecnologia para este fim. Como conclusão deste trabalho as mudanças relâmpadas da grande disponibilidade de dados no ambiente virtual é de enorme valia para o processo ensino-aprendizado.

  10. Platinum Inhibits Low-Temperature Dry Lean Methane Combustion through Palladium Reduction in Pd-Pt/Al2 O3 : An In Situ X-ray Absorption Study.

    Science.gov (United States)

    Nassiri, Hanieh; Lee, Kee-Eun; Hu, Yongfeng; Hayes, Robert E; Scott, Robert W J; Semagina, Natalia

    2017-01-18

    Palladium-platinum bimetallic catalysts supported on alumina with palladium/platinum molar ratios ranging from 0.25 to 4 are studied in dry lean methane combustion in the temperature range of 200 to 500 °C. Platinum addition decreases the catalyst activity, which cannot be explained by the decrease in dispersion or the structure sensitivity of the reaction. In situ X-ray absorption near-edge structure and extended X-ray absorption fine structure spectroscopy measurements have been conducted for monometallic Pd, Pt, and 2:1 Pd-Pt catalysts. Monometallic palladium is fully oxidized in the full temperature range, whereas platinum addition promotes palladium reduction, even in a reactive oxidizing environment. The Pd/PdO weight ratio in bimetallic Pd-Pt 2:1 catalysts decreases from 98/2 to 10/90 in the 200-500 °C temperature range under the reaction conditions. Thus, platinum promotes the formation of the reduced palladium phase with a significantly lower activity than that of oxidized palladium. The study sheds light on the effect of platinum on the state of the active palladium surface under low-temperature dry lean methane combustion conditions, which is important for methane-emission control devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.J.

    1986-06-03

    A variable power internal combustion engine is described which consists of: a separate air compressor for receiving and compressing a flow of air to a given pressure, the compressor having an inlet valve introducing a flow of air into the compressor and an outlet valve for exhausting compressed air out of the compressor into a compressed air storage means, at least one expander having a cylinder, a cylinder head closing an end of the cylinder, a piston reciprocally mounted in the cylinder for movement away from the cylinder head in a power stroke from an initial position defining a combustion chamber within the cylinder between the cylinder head and the piston, the compressed air storage means receiving the pressurized flow of air from the compressor and being of a volume adequate to provide compressed air in the combustion chamber essentially at the given pressure essentially over the power output of the engine, means for introducing an amount of combustible fuel in the compressed charge to be present with compressed air in the combustion chamber and providing combustion of the amount of fuel in the cylinder with the inlet and exhaust valves closed, cam shaft means in contact with the piston for absorbing and storing the energy of the power stroke of the piston and controlling movement of the piston within the cylinder during the exhaust stroke; the means for varying the volume of the combustion chamber being controlled in accordance with power requirements to provide variable power output and improved efficiency of the engine at power outputs reduced relative to a given design power output of the engine by providing a variable expansion ratio of a minimum of at least about 30 to 1 at the given design power output and higher with reduced power output.

  12. Ciencia básica y ciencia aplicada Basic science and applied science

    Directory of Open Access Journals (Sweden)

    Ruy Pérez-Tamayo

    2001-08-01

    Full Text Available En el contexto de una intervención en el Foro de Consulta Democrática de la Coordinación de los Institutos Nacionales de Salud sobre Enseñanza e Investigación en Salud, realizado en el Instituto Nacional de Cardiología Ignacio Chávez, se hace una revisión crítica de la clasificación convencional de la ciencia en básica y aplicada; además, se analiza lo que deberían ser la enseñanza y la investigación en salud. Para apoyar su propia clasificación de la ciencia en "bien hecha", la cual "genera conocimientos verificables sobre la realidad" y la "mal hecha", improductiva o productora de "puras mentiras" y "no debe patrocinarse", el autor revisa las definiciones utilitaristas y peyorativas como las que establecen ciencia comprometida y ciencia pura, ciencia útil y ciencia inútil, y ciencia práctica y ciencia esotérica, como sinónimos de ciencia aplicada y ciencia básica y afirma que, en México, esta diferenciación "para lo único que ha servido en el pasado es para justificar la reducción en el apoyo oficial a la ciencia básica, porque no estaba dirigida a resolver ´los problemas nacionales´o porque no caía en las prioridades establecidas en ese sexenio". En cuanto a educación e investigación en salud reconoce que el programa actual de formación de investigadores tiene una eficiencia muy baja y propone un estudio científico crítico, realizado por un equipo de especialistas, interdisciplinario, "para integrar la carrera del investigador científico desde la captura de la juventud inteligente hasta la jubilación o muerte del investigador" y para el cual la evaluación de la eficiencia del apoyo a sus proyectos de investigación no se restrinja a si se publicó o no un artículo "pues la calidad del trabajo científico y la contribución de un investigador al desarrollo de la ciencia no es nada más el número de sus publicaciones". El texto completo en inglés de este artículo está disponible en: http

  13. Novas tecnologias aplicadas às embalagens de alimentos

    Directory of Open Access Journals (Sweden)

    Flávia De Floriani Pozza Rebello

    2009-12-01

    Full Text Available Com o desenvolvimento da indústria de alimentos, as embalagens têm se aperfeiçoado, indo além de sua função básica de proteger o alimento contra danos mecânicos e contaminações químicas e microbiológicas. Elas têm cada vez mais desempenhando papel de destaque, contribuindo ativamente para a venda de um produto. Assim, as indústrias de embalagens têm procurado atender aos consumidores mais exigentes e juntamente aos centros de pesquisa e universidades, têm investido mais em estudos de novas tecnologias, a fim de prolongar as características de qualidade do alimento, conferir melhor aparência, maior proteção mecânica no embarque, transporte, desembarque e nos supermercados, oferecer embalagens mais compactas, que ocupem menos espaço na geladeira, com abertura e fechamento mais fáceis, e que utilizem materiais de fácil reciclagem ou decomposição no ambiente. Com o objetivo de atender às novas expectativas das indústrias de alimentos e dos consumidores, surgem as embalagens ativas e as embalagens inteligentes. As embalagens ativas são aquelas que interagem de alguma forma com o alimento, seja liberando substâncias conservantes ao longo da vida de prateleira do produto, ou “corrigindo” alguns problemas naturais do alimento, como sabor amargo por exemplo, em que algumas enzimas podem ser adicionadas ao material de embalagem, minimizando este problema e tornando o produto mais saboroso. Já as embalagens inteligentes indicam as modificações químicas às quais os alimentos estão passando, como mudanças de pH, por exemplo, indicando alterações na qualidade do produto.

  14. Combustion synthesis of bulk nanocrystalline iron alloys

    OpenAIRE

    Licai Fu; Jun Yang; Weimin Liu

    2016-01-01

    The controlled synthesis of large-scale nanocrystalline metals and alloys with predefined architecture is in general a big challenge, and making full use of these materials in applications still requires greatly effort. The combustion synthesis technique has been successfully extended to prepare large-scale nanocrystalline metals and alloys, especially iron alloy, such as FeC, FeNi, FeCu, FeSi, FeB, FeAl, FeSiAl, FeSiB, and the microstructure can be designed. In this issue, recent progress on...

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

    Science.gov (United States)

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

    2011-08-30

    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.

  16. Combustion and regulation; Combustion et reglementation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This conference was organized after the publication of the French by-law no 2010 relative to combustion installations and to the abatement of atmospheric pollution. Five topics were discussed during the conference: the new regulations, their content, innovations and modalities of application; the means of energy suppliers to face the new provisions and their schedule; the manufacturers proposals for existing installations and the new equipments; the administration control; and the impact of the new measures on exploitation and engineering. Twenty papers and 2 journal articles are reported in these proceedings. (J.S.)

  17. Biotechnology applied to salmoniculture Biotecnologia aplicada à salmonicultura

    Directory of Open Access Journals (Sweden)

    Iván Valdebenito Isler

    2009-07-01

    machos. Essas ações são realizadas com GnRHa em doses próximas de 10ìg/kg de peixe. Após a maturidade sexual, a manipulação de gametas "in vitro" deve ser feita, quer seja devido ao armazenamento prolongado (particularmente "milt", pois têm que ser transportado ao local em que ocorrerá a fecundação, ou para aguardar os resultados ictiopatológicos, geralmente tomada dos reprodutores. A produção de população "todas fêmeas" também é comum. Frequentemente, estas populações em truta arcoíris são triplóides (por meio de choque temperatura próxima a 28 ºC ou pressão próxima de 8.000 psi para obter espécies estéreis que melhoram desempenho produtivo das populações cultivadas sem sinais de maturidade sexual. Além disso, as perspectivas de utilização industrial de organismos transgênicos na criação de salmonídeos são analisadas.

  18. Experimental investigation on the combustion characteristics of aluminum in air

    Science.gov (United States)

    Feng, Yunchao; Xia, Zhixun; Huang, Liya; Yan, Xiaoting

    2016-12-01

    With the aim of revealing the detailed process of aluminum combustion in air, this paper reports an experimental study on the combustion of aluminum droplets. In this work, the aluminum wires were exposed and heated by a CO2 laser to produce aluminum droplets, and then these droplets were ignited and burnt in air. The changing processes of aluminum wires, droplets and flames were directly recorded by a high-speed camera, which was equipped with a high magnification zoom lens. Meanwhile, the spectrum distribution of the flame was also registered by an optical spectrometer. Besides, burning residuals were collected and analyzed by the methods of Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). Experimental results show that, during combustion, the aluminum droplet is covered by a spherical vapor-phase flame, and the diameter of this flame is about 1.4 times of the droplet diameter, statistically. In the later stages of combustion, the molten aluminum and condensed oxide products can react to generate gaseous Al and Al2O spontaneously. Little holes are found on the surface of residuals, which are the transport channels of gaseous products, namely the gaseous Al and Al2O. The combustion residuals are consisted by lots of aluminum oxide particles with diameters less than 1 μm.

  19. Fast start-up of microchannel fuel processor integrated with an igniter for hydrogen combustion

    Science.gov (United States)

    Ryi, Shin Kun; Park, Jong Soo; Cho, Song Ho; Kim, Sung Hyun

    A Pt-Zr catalyst coated FeCrAlY mesh is introduced into the combustion outlet conduit of a newly designed microchannel reactor (MCR) as an igniter of hydrogen combustion to decrease the start-up time. The catalyst is coated using a wash-coating method. After installing the Pt-Zr/FeCrAlY mesh, the reactor is heated to its running temperature within 1 min with hydrogen combustion. Two plate-type heat-exchangers are introduced at the combustion outlet and reforming outlet conduits of the microchannel reactor in order to recover the heat of the combustion gas and reformed gas, respectively. Using these heat-exchangers, methane steam reforming is carried out with hydrogen combustion and the reforming capacity and energy efficiency are enhanced by up to 3.4 and 1.7 times, respectively. A compact fuel processor and fuel-cell system using this reactor concept is expected to show considerable advancement.

  20. Co-combustion: A summary of technology

    Directory of Open Access Journals (Sweden)

    Leckner Bo

    2007-01-01

    Full Text Available Co-combustion of biomass or waste together with a base fuel in a boiler is a simple and economically suitable way to replace fossil fuels by biomass and to utilize waste. Co-combustion in a high-efficiency power station means utilization of biomass and waste with a higher thermal efficiency than what otherwise had been possible. Due to transport limitations, the additional fuel will only supply a minor part (less than a few hundreds MW fuel of the energy in a plant. There are several options: co-combustion with coal in pulverized or fluidized bed boilers, combustion on added grates inserted in pulverized coal boilers, combustors for added fuel coupled in parallel to the steam circuit of a power plant, external gas producers delivering its gas to replace an oil, gas or pulverized fuel burner. Furthermore biomass can be used for reburning in order to reduce NO emissions or for afterburning to reduce N2O emissions in fluidized bed boilers. Combination of fuels can give rise to positive or negative synergy effects, of which the best known are the interactions between S, Cl, K, Al, and Si that may give rise to or prevent deposits on tubes or on catalyst surfaces, or that may have an influence on the formation of dioxins. With better knowledge of these effects the positive ones can be utilized and the negative ones can be avoided.

  1. Co-combustion - a summary of technology

    Energy Technology Data Exchange (ETDEWEB)

    Bo Leckner [Chalmers University of Technology, Goeteborg (Sweden). Dept. of Energy and Environment

    2007-07-01

    Co-combustion of biomass or waste together with a base fuel in a boiler is a simple and economically suitable way to replace fossil fuels by biomass and to utilise waste. Co-combustion in a high-efficiency power station means utilisation of biomass and waste with a higher thermal efficiency than what otherwise had been possible. Due to transport limitations, the additional fuel will only supply a minor part (less than a few hundreds MW{sub fuel}) of the energy in a plant. There are several options: co-combustion with coal in pulverised or fluidised bed boilers, combustion on added grates inserted in pulverised coal boilers, combustors for added fuel coupled in parallel to the steam circuit of a power plant, external gas producers delivering its gas to replace an oil, gas or pulverised fuel burner. Furthermore biomass can be used for reburning in order to reduce NO emissions or for afterburning to reduce N{sub 2}O emissions in fluidised bed boilers. Combination of fuels can give rise to positive or negative synergy effects, of which the best known are the interactions between S, Cl, K, Al, and Si that may give rise to or prevent deposits on tubes or on catalyst surfaces, or that may have an influence on the formation of dioxins. With better knowledge of these effects the positive ones can be utilised and the negative ones can be avoided. 71 refs., 19 figs., 5 tabs.

  2. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  3. 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

  4. Radiative Augmented Combustion.

    Science.gov (United States)

    1985-08-12

    86-0085 In 00I to RADIATIVE AUGMENTED COMBUSTION MOSHE LAVID M.L. ENERGIA , INC. P.O. BOX 1468 1 PRINCETON, NEW JERSEY 08542 AUGUST 1985 *.. plo...Combustion conducted at M.L. ENERGIA . It is funded by the Air Force Office of Scientific Research under Contract No. F49620-83-C-0133, with Dr. J.M...reported. It covers the second year of the contract, from July 15, 1984 through July 14, 1985. The work was performed at ENERGIA , Princeton, New Jersey

  5. Transition nozzle combustion system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  6. 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. ...

  7. 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

    achieved. [Espanol] La combustion de aceite combustible residual emite sustancias nocivas como particulas carbonaceas, oxidos de nitrogeno y trioxido de azufre, a niveles inadmisibles. Agua emulsionada en el combustible reduce sustancialmente dichas emisiones, lograndose ademas, en la mayoria de los casos, un ahorro neto en el consumo de combustible. Se muestran los efectos beneficos de quemar el aceite combustible residual en forma de emulsion, asi como el metodo para producir una emulsion adecuada. La tecnologia del combustible emulsionado ofrece una opcion de bajo costo para reducir la contaminacion atmosferica. La calidad del aceite combustible residual ha estado declinando durante las ultimas decadas debido: 1. Al aumento en la produccion de petroleos crudos pesados generalmente con mayor contenido de asfaltenos y de azufre. 2. A menor disponibilidad de residuos de la destilacion al vacio debido a su conversion a productos de mayor valor. 3. A procesos de conversion mas intensivos, como cracking catalitico, {sup v}isbreaking{sup ,} etc., que aumentan la concentracion de asfaltenos en los fondos, ocasionando problemas de inestabilidad. 4. Al aumento en el contenido de vanadio y de otros metales a medida que aumenta la concentracion de asfaltenos. El uso de aceite combustible emulsionado proporciona un medio eficaz y economico para reducir sustancialmente las emisiones nocivas a la atmosfera. La emulsion contiene particulas de agua de un diametro entre 2 y 20 micras, dispersadas uniformemente dentro del aceite combustible, en una proporcion generalmente enter 5 y 10%; ademas contiene un agente tensioactivo para asegurar una emulsion estable, capaz de resistir los esfuerzos cortantes del sistema de bombeo y distribucion. Cuando las gotas de aceite combustible atomizado llegan a la camara de combustion, el agua esmulsionada en ellas se convierte instantaneamente en vapor de alta presion, ocasionando una violenta atomizacion secundaria. El efecto de esta atomizacion

  8. Ignition of Metal Powders in Combustion Products of Model Fuel

    Science.gov (United States)

    1974-11-13

    y AD/A-001 172 IGNITION OF METAL POWDERS IN COMBUSTION PRODUCTS OF MODEL FUEL A. K. Klyauzov, et al Foreign Technology...S. Air Force UNCLASSIFIED »b. s»ouc » "I»0«T TITLE IGNITION OF METAL POWDERS IN COMBUSTION PRODUCTS OF MODEL FUEL f* OCJCPIPTIVK NOTKI (Typ* o...report mnd Inclumiv «**»••) Translation S »UTMö«I|I ( Firn tSSS», rnlddl* Inltlml, faar .tarna; A. K. Klyauzov, M. M. Arsh, et al 6

  9. Experimental combustion an introduction

    CERN Document Server

    Mishra, D P

    2014-01-01

    ""… other books available in this area do not cover the detailed topics covered here. Energy and combustion is a hot issue. It is expected to be even hotter with more demand in this area as we search for cleaner methods of energy conversion from chemical to thermal energy.""-Ashwani K. Gupta, Department of Mechanical Engineering, University of Maryland, College Park, USA

  10. Coal combustion research

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C.S.

    1996-06-01

    This section describes research and development related to coal combustion being performed for the Fossil Energy Program under the direction of the Morgantown Energy Technology Center. The key activity involves the application of chaos theory for the diagnosis and control of fossil energy processes.

  11. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    . 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...

  12. Combustion Models in Finance

    CERN Document Server

    Tannous, C

    2001-01-01

    Combustion reaction kinetics models are used for the description of a special class of bursty Financial Time Series. The small number of parameters they depend upon enable financial analysts to predict the time as well as the magnitude of the jump of the value of the portfolio. Several Financial Time Series are analysed within this framework and applications are given.

  13. Flameless Combustion Workshop

    Science.gov (United States)

    2005-09-20

    operating hours, to produce low emission levels of NOx, CO and UHC . Gas turbine combustion stability has increasingly become a crucial design issue as...achieved proved: "* Safe and reliable operation ofgas turbine combustors "* Low emissions of NO., CO and UHC These results have clear economically

  14. Turbulent Combustion in Aluminum-air Clouds for Different Scale Explosion Fields

    Science.gov (United States)

    Kuhl, Allen; Balakrishnan, Kaushik; Bell, John; Beckner, Vincent

    2015-06-01

    We have studied turbulent combustion effects in explosions, and proposed heterogeneous continuum models for the turbulent combustion fields. Also we have proposed an induction-time model for the ignition of Al particle clouds, based on Arrhenius fits to the shock tube data of Boiko. Here we explore scaling issues associated with Al particle combustion in such explosions. This is a non-premixed combustion system; the global burning rate is controlled by rate of turbulent mixing of fuel (Al particles) with air. For similitude reasons, the turbulent mixing rates should scale with the explosion length and time scales. However, the induction time for ignition of Al particles depends on an Arrhenius function, which is independent of such scales. To study this, we have performed numerical simulations of turbulent combustion in unconfined Al-SDF (shock-dispersed-fuel) explosion fields at different scales. Three different charge masses were assumed: 1-g, 1-kg and 1-T Al-powder charges. We found that there are two combustion regimes: an ignition regime--where the burning rate decays a power law function of time, and a turbulent combustion regime--where the burning rate decays exponentially with time.

  15. LÓGICA DIFUSA APLICADA A LA TOMA DE DECISIONES

    Directory of Open Access Journals (Sweden)

    Daniel Alfonso Robaina

    2010-11-01

    estrategia general de la organización. La Empresa Constructora y Reparadora de la Industria del Níquel ECRIN, pertenece al sector de la Construcción en la región de Moa,  el que despunta hacia nuevos retos;  el desarrollo de dos fábricas productoras de níquel, constituye un  atractivo para capital nacional y extranjero, donde la competitividad se traduce en satisfacción de expectativas de clientes  internos, externos y proveedores.

     

    This paper shows the quantitative analysis methods, these are applied to make decision task in which are involved uncertainty criteria, these method allows the participation of workers, experts and team work, at the general strategy design of organization. The Construction and Repairing Enterprise of Nickel Industry ECRIN, belongs to building sector at MOA region, which open out to a new challenges; the development of two productive factories of nickel raw became in an interesting attractive sector for a national investment and abroad, where competitiveness  turn into the expectation satisfaction of internal and external customers and suppliers.

  16. Neurociencia computacional aplicada a la liberación de transmisores por exocitosis

    OpenAIRE

    Fernández Peruchena, Carlos María

    2008-01-01

    Falta por incorporar las palabras clave La Tesis presentada, realizada bajo la dirección del Dr. Guillermo Álvarez de Toledo Naranjo, lleva por título Neurocincia computacional aplicada a la liberación de transmisores por exocitosis. El trabajo desarrollado en esta Tesis forma parte de la actividad de investigación sobre secreción celular que se lleva a cabo en el grupo de investigación del Dr. Álvarez de Toledo (CVI-209), dentro del proyecto BFI2001-3199. El grupo de investigación CVI-209...

  17. Investigación básica y aplicada en contabilidad

    OpenAIRE

    García Casella, Carlos Luis, co-dir.

    2004-01-01

    Se aborda la cuestión de la investigación científica en contabilidad, procurando que sea considerada dentro de las ciencias sociales. Esto genera uso del método científico en la tarea de investigación contable. El carácter de ciencia factual, cultural, aplicada de la contabilidad se considera esencial frente a normas contables profesionales que la reducen a mera técnica en nuestro país. Descartada la idea de arte o tecnología social se presenta un enfoque de contabilidad que supera lo que hab...

  18. Investigación básica y aplicada en contabilidad

    OpenAIRE

    García Casella, Carlos Luis

    2004-01-01

    Se aborda la cuestión de la investigación científica en contabilidad, procurando que sea considerada dentro de las ciencias sociales. Esto genera uso del método científico en la tarea de investigación contable. El carácter de ciencia factual, cultural, aplicada de la contabilidad se considera esencial frente a normas contables profesionales que la reducen a mera técnica en nuestro país. Descartada la idea de arte o tecnología social se presenta un enfoque de contabilidad que supera lo que hab...

  19. Projecto Rodentia : etologia aplicada na sala de aula do 1º Ciclo

    OpenAIRE

    2008-01-01

    p. 275-279 O Projecto Rodentia, implementado no ano 2006/2007, visa promover a cultura científica em alunos do 1º ciclo do Ensino Básico, familiarizando-os com o Método Científico e desenvolvendo competências conceptuais, processuais e atitudinais, com base na Etologia Aplicada e na reflexão ética sobre o bem-estar animal. Foram instalados em três salas de aula habitats especialmente desenhados, contendo cada um dois ratos de laboratório. Inicialmente orien...

  20. Medidas de frecuencia, asociación e impacto en investigación aplicada

    OpenAIRE

    2008-01-01

    En la Sociedad actual del conocimiento y la información es preciso disponer de herramientas básicas para medir los fenómenos epidemiológicos como la enfermedad, la incapacidad o la siniestralidad laboral. Las formas de medir son instrumentos que se deben conocer y aplicar para planificar y tomar decisiones en Salud Pública y en Salud Laboral. El objetivo de este artículo es dar a conocer las principales medidas de frecuencia, asociación e impacto utilizadas en investigación aplicada, clínica ...

  1. Estrategia de comunicación y marketing aplicada a la empresa Nelybel

    OpenAIRE

    García Martín, Beatriz

    2012-01-01

    El objetivo principal del proyecto es plantear una estrategia de comunicación y marketing útil para aplicarla a la empresa de regalos Nelybel. Los objetivos secundarios son aprender a llevar a cabo una estrategia de comunicación y marketing partiendo casi de cero, realizar una investigación de mercado provincial y un análisis de la competencia y ayudar con la publicidad y promoción de la empresa. García Martín, B. (2012). Estrategia de comunicación y marketing aplicada a la empresa Nely...

  2. Combustion calorimetry experimental chemical thermodynamics

    CERN Document Server

    Sunner, Stig

    1979-01-01

    Combustion Calorimetry deals with expertise knowledge concerning the calorimetry of combustion reactions of an element or compound. After defining the use of units and physical constants, the book discusses the basic principles of combustion calorimetry and the various instruments and calorimeters used in the experiments to measure operations concerning temperatures and its time variations. One paper discusses the theory and design criteria of combustion calorimeter calibration. Another paper discusses the results obtained from a combustion calorimeter after it has measured the energy or entha

  3. Modelling of CWS combustion process

    Science.gov (United States)

    Rybenko, I. A.; Ermakova, L. A.

    2016-10-01

    The paper considers the combustion process of coal water slurry (CWS) drops. The physico-chemical process scheme consisting of several independent parallel-sequential stages is offered. This scheme of drops combustion process is proved by the particle size distribution test and research stereomicroscopic analysis of combustion products. The results of mathematical modelling and optimization of stationary regimes of CWS combustion are provided. During modeling the problem of defining possible equilibrium composition of products, which can be obtained as a result of CWS combustion processes at different temperatures, is solved.

  4. Wear aspects of internal combustion engine valves

    Science.gov (United States)

    Panţuru, M.; Chicet, D.; Paulin, C.; Alexandru, A.; Munteanu, C.

    2016-08-01

    Because the surface engineering is becoming an increasingly viable alternative to the constructive changes made to improve the efficiency of internal combustion engines, have been proposed and tested various types of coatings of some organs of internal combustion engines. One vital organ is the engine valves, which is subjected during operation to combined thermal, mechanical, corrosion and wear solicitations, which are leading to severe corrosion and complete breakdown. In this paper were analyzed aspects of valves wear and the active surfaces were coated using the atmospheric plasma spraying method (APS) with two commercial powders: Ni-Al and YSZ. Microstructural analyzes were made on these layers and also observations regarding the possibility of using them as thermal barrier and anti-oxidant coatings.

  5. Synthesis of functional materials in combustion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zhuravlev, V. D., E-mail: zhvd@ihim.uran.ru; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I. [Russian Academy of Sciences, Institute of Solid State Chemistry, Ural Branch (Russian Federation)

    2015-12-15

    The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating–reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al{sub 2}O{sub 3}, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO{sub 2}, and manganites, cobaltites, and aluminates of rare earth elements.

  6. Synthesis of functional materials in combustion reactions

    Science.gov (United States)

    Zhuravlev, V. D.; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

    2015-12-01

    The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating-reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al2O3, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO2, and manganites, cobaltites, and aluminates of rare earth elements.

  7. Effect of metal doping into Ce0.5Zr0.5O2 on catalytic activity of MnOx/Ce0.5-xZr0.5-xM0.2xOy/Al2O3 for benzene combustion

    Institute of Scientific and Technical Information of China (English)

    YAN Shenghui; WANG Jianli; ZHONG Junbo; CHEN Yaoqiang; LIU Zhimin; CAO Hongyan; GONG Maochu

    2008-01-01

    The research investigated the effect of doping two metals separately or together into Ce0.5Zr0.5O2 on the catalytic activity of MnOx/Ce0.5-xZr0.5-xM0.2xOy/Al2O3 (M=Y, Mn, Y and Mn) for catalytic combustion of benzene. The prepared catalysts were characterized by X-ray diffraction (XRD), surface area analysis, oxygen storage capacity (OSC), and H2-temperature programmed reduction (H2-TPR). Cata-lytic test was performed on a conventional fixed bed flow reactor. The characterization results revealed that Y and Mn ions entered into the ceria-zirconia mixed oxides framework, which improved the textural properties and greatly promoted the MnOx dispersion on the support surface. The complete conversion temperature of benzene on MnOx/Ce0.4Zr0.4Y0.1Mn0.1Oy/Al2O3 was 563 K, and the selectivity of carbon dioxides was 99%. This catalyst could be applied in a wide range of GHSV and wide concentration condition, showing great potential for application.

  8. Time Resolved FTIR Analysis of Combustion of Ethanol and Gasoline Combustion in AN Internal Combustion Engine

    Science.gov (United States)

    White, Allen R.; Sakai, Stephen; Devasher, Rebecca B.

    2011-06-01

    In order to pursue In Situ measurements in an internal combustion engine, a MegaTech Mark III transparent spark ignition engine was modified with a sapphire combustion chamber. This modification will allow the transmission of infrared radiation for time-resolved spectroscopic measurements by an infrared spectrometer. By using a Step-scan equipped Fourier transform spectrometer, temporally resolved infrared spectral data were acquired and compared for combustion in the modified Mark III engine. Measurements performed with the FTIR system provide insight into the energy transfer vectors that precede combustion and also provides an in situ measurement of the progress of combustion. Measurements were performed using ethanol and gasoline.

  9. Experimental chemical thermodynamics. Volume I. Combustion calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sunner, S.; Mansson, M. (eds.)

    1979-01-01

    This book contains 18 chapters. The information included is: units and physical constants; basic principles of combustion calorimetry; calibration of combustion calorimeters; test and auxiliary substances in combustion calorimetry; strategies in the calculation of standard-state energies of combustion from the experimentally determined quantities; assignments of uncertainties; presentation of combustion calorimetric data in the primary literature; general techniques for combustion of liquid/solid organic compounds by oxygen bomb calorimetry; combustion of liquid/solid organic compounds with non-metallic hetero-atoms; combustion calorimetry of metals and simple metallic compounds; combustion calorimetry of organometallic compounds; combustion in fluorine and other halogens; bomb combustion of gaseous compounds in oxygen; oxygen flame calorimetry; fluorine flame calorimetry; combustion calorimetry as a technological service; trends in combustion calorimetry; and from the history of combustion calorimetry. (DP)

  10. Estrategias flexibilizadoras aplicadas por las empresas del sector avícola del estado Zulia

    Directory of Open Access Journals (Sweden)

    María Bonomie

    2008-01-01

    Full Text Available El artículo tiene como objetivo, analizar las estrategias flexibilizadoras aplicadas en el proceso productivo por las empresas del sector avícola, específicamente las empresas productoras de pollo del estado Zulia. Para tal fin, se describe el proceso productivo de estas empresas y además se identifican las estrategias aplicadas considerando los acontecimientos económicos influenciados por cambios políticos que en los últimos años han incidido en las empresas productoras de pollo. Se realizó una revisión bibliográfica para determinar los criterios de clasificación de las estrategias, asumiendo la establecida por Gamboa y col. (2001. Se diseñó un instrumento semiestructurado, el cual fue administrado a los gerentes y trabajadores de las empresas analizadas. Los resultados obtenidos reflejan, que las empresas utilizan las estrategias con la finalidad de reestructurar y modernizar sus procesos productivos, mejorar continuamente sus productos e introducir nueva tecnología. Se concluye que estas empresas logran incrementar la productividad, aumentando la cantidad de productos ante la utilización óptima de los recursos humanos y tecnológicos, optimización que implica una reducción de costos de producción para poder expandirse y ofrecer precios competitivos en el mercado.

  11. Magnetic properties of hard-soft SrFe{sub 10}Al{sub 2}O{sub 19}/Co{sub 0.8}Ni{sub 0.2}Fe{sub 2}O{sub 4} ferrite synthesized by one-pot sol–gel auto-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Torkian, Shahab; Ghasemi, Ali, E-mail: ali13912001@yahoo.com; Razavi, Reza Shoja

    2016-10-15

    SrFe{sub 10}Al{sub 2}O{sub 19}/Co{sub 0.8}Ni{sub 0.2}Fe{sub 2}O{sub 4} hard/soft nanocomposite ferrites with different content of soft phase have been prepared by simple one-pot sol–gel auto-combustion route. X-ray diffraction (XRD), field emission scanning electron microscopy and vibrating ample magnetometer were employed to analysis of structural and magnetic features of synthesized samples. XRD patterns reflect the formation of hard/soft composites of ferrites without the existence of any kind of secondary phases. Narrow size distributions of particles were formed by sol–gel method. Single smooth hysteresis loops of nanocomposites show the presence of exchange coupling between hard and soft phases. Nanocomposite with 15 wt% of soft phase reaches the highest M{sub r}/M{sub s} ratio of 0.63. Compared to the physical mixing of hard/ soft nanocomposites, the one-pot sol–gel auto-combustion method could be considered as a suitable method for synthesizing exchange coupled magnet. - Highlights: • Sol–gel autocombustion method was used to prepare hard/soft magnetic nanocomposite. • Structural and microscopic analysis confirmed formation of two distinct phases. • The samples prepared by physical mixing method show a “bee waist” hysteresis loop. • High level of homogenous mixing of two phases results in single hysteresis loop. • The relatively strong exchange coupling behavior was observed in nanocomposites.

  12. II SEMINARIO INTERNACIONAL EN CIENCIAS APLICADAS “Una mirada hacia la innovación y el desarrollo sostenible”

    OpenAIRE

    Diana Verónica Cortés-Espinosa; et. al.

    2013-01-01

    INTRODUCCIÓN La Química, Biología y las Matemáticas son el pilar de las ciencias aplicadas. La investigación en el área básica se ve reflejada en el desarrollo de disciplinas como las ciencias de la salud, ingenierías y ciencias ambientales. De esta forma, la integración entre la investigación básica y las ciencias aplicadas es fundamental en el desarrollo del profesional moderno. Considerando lo anterior la Facultad de Ciencias Exactas Físicas y Naturales organiza el segundo seminario in...

  13. II SEMINARIO INTERNACIONAL EN CIENCIAS APLICADAS “Una mirada hacia la innovación y el desarrollo sostenible”

    OpenAIRE

    Diana Verónica Cortés-Espinosa; et. al.

    2013-01-01

    INTRODUCCIÓN La Química, Biología y las Matemáticas son el pilar de las ciencias aplicadas. La investigación en el área básica se ve reflejada en el desarrollo de disciplinas como las ciencias de la salud, ingenierías y ciencias ambientales. De esta forma, la integración entre la investigación básica y las ciencias aplicadas es fundamental en el desarrollo del profesional moderno. Considerando lo anterior la Facultad de Ciencias Exactas Físicas y Naturales organiza el segundo seminario in...

  14. Psicologia del color aplicada a los cursos virtuales para mejorar el nivel de aprendizaje en los estudiantes

    OpenAIRE

    Canté García, Julio Francisco

    2017-01-01

    La psicología del color aplicada a la elaboración de la interfaz que se diseñe para un curso virtual jugará un papel importante en las posibilidades de aprender. Si no es elaborada de manera adecuada, repercute inmediatamente en la motivación y el aprendizaje del estudiante. La interfaz gráfica ha de ser estimulante, explícita, consistente y funcional, para que el alumno la comprenda y explore fácilmente. La psicologia del color aplicada a l'elaboració de la interfície que es dissenyi per ...

  15. Psicologia del color aplicada a los cursos virtuales para mejorar el nivel de aprendizaje en los estudiantes

    OpenAIRE

    Canté García, Julio Francisco

    2017-01-01

    La psicología del color aplicada a la elaboración de la interfaz que se diseñe para un curso virtual jugará un papel importante en las posibilidades de aprender. Si no es elaborada de manera adecuada, repercute inmediatamente en la motivación y el aprendizaje del estudiante. La interfaz gráfica ha de ser estimulante, explícita, consistente y funcional, para que el alumno la comprenda y explore fácilmente. La psicologia del color aplicada a l'elaboració de la interfície que es dissenyi per ...

  16. Turbulent combustion in aluminum-air clouds for different scale explosion fields

    Science.gov (United States)

    Kuhl, Allen L.; Balakrishnan, Kaushik; Bell, John B.; Beckner, Vincent E.

    2017-01-01

    This paper explores "scaling issues" associated with Al particle combustion in explosions. The basic idea is the following: in this non-premixed combustion system, the global burning rate is controlled by rate of turbulent mixing of fuel (Al particles) with air. From similarity considerations, the turbulent mixing rates should scale with the explosion length and time scales. However, the induction time for ignition of Al particles depends on an Arrhenius function, which is independent of the explosion length and time. To study this, we have performed numerical simulations of turbulent combustion in unconfined Al-SDF (shock-dispersed-fuel) explosion fields at different scales. Three different charge masses were assumed: 1-g, 1-kg and 1-T Al-powder charges. We found that there are two combustion regimes: an ignition regime—where the burning rate decays as a power-law function of time, and a turbulent combustion regime—where the burning rate decays exponentially with time. This exponential dependence is typical of first order reactions and the more general concept of Life Functions that control the dynamics of evolutionary systems. Details of the combustion model are described. Results, including mean and rms profiles in combustion cloud and fuel consumption histories, are presented.

  17. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  18. MnOx/Ce0.5+xZr0.4-xLa0.1O1.95-Al2O3 catalysts used for benzene catalytic combustion

    Institute of Scientific and Technical Information of China (English)

    LIAO Chuanwen; LI Xiaoshuang; WANG Jianli; CHEN Yongdong; CAO Hongyan; CHEN Yaoqiang; GONG Maochu

    2011-01-01

    Complete oxidation of benzene over supported manganese oxides catalysts was studied. Composite supports Ce0.5+xZr0.4_xLao.1O1.95-Al2O3 (x=0, 0.1, 0.2, 0.3, 0.4), and CeO2-A12O3 were prepared by co-precipitation method, and manganese oxides (MnOx) catalysts were prepared by incipient wetness method. Catalytic activity was performed in a conventional fixed bed flow reactor.Among these catalysts, MnOx supported on Ce0.8Zr0.1La0.1O1.95-Al2O3 was found to have the highest catalytic activity for benzene oxidation.The complete conversion temperature of benzene on MnOx/Ce0.8Zr0.1La0.1O1.95-Al2O3 was 328 ℃. The catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) specific surface area, X-ray photoelectron spectra (XPS) and He-temperature programmed reduction (H2-TPR). The results of BET and XRD measurements indicated that the addition of ZrO2 improved the textural properties. XPS measurements showed that MnOx was composed of MnO2 and Mn2O3. The catalysts reported in this work have significant potential in industrial application for their high performance and low cost.

  19. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol

    Directory of Open Access Journals (Sweden)

    Peterson GP

    2011-01-01

    Full Text Available Abstract An experimental investigation of the combustion behavior of nano-aluminum (n-Al and nano-aluminum oxide (n-Al2O3 particles stably suspended in biofuel (ethanol as a secondary energy carrier was conducted. The heat of combustion (HoC was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results.

  20. Combustion science and engineering

    CERN Document Server

    Annamalai, Kalyan

    2006-01-01

    Introduction and Review of Thermodynamics Introduction Combustion Terminology Matter and Its Properties Microscopic Overview of Thermodynamics Conservation of Mass and Energy and the First Law of Thermodynamics The Second Law of Thermodynamics Summary Stoichiometry and Thermochemistry of Reacting Systems Introduction Overall Reactions Gas Analyses Global Conservation Equations for Reacting Systems Thermochemistry Summary Appendix Reaction Direction and Equilibrium Introduction Reaction Direction and Chemical Equilibrium Chemical Equilibrium Relations Vant Hoff Equation Adi

  1. Combustion Characteristics of Sprays

    Science.gov (United States)

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  2. Combustible Cartridge Case Characterization

    Science.gov (United States)

    1984-02-01

    University (NYU) has resulted in the selection of two cross-linked melamine / formaldehyde acrylic styrene resin systems that can be used in the beater additive... melamine resin Akaradit II stabilizer 20. ABSTRACT (con) Test coupons of combustible cartridge case material were fabricated using these recommended...and agitated for 30 min before the pH was slowly lowered to 3 with p-toluene sulfonic acid. In order to maintain this pH in the felting tank, it was

  3. High Gravity (g) Combustion

    Science.gov (United States)

    2006-02-01

    required thrust-to-weight ratio goals. Shorter residence times in the combustion chamber may reduce the NOx emissions, but the CO and UHC emissions then...Emissions analyzing equipment is available to detect CO, CO2, NOx, O2, and total unburned hydrocarbons ( UHC ) at the combustor exit plane. Emissions... UHC ) emissions along with the CO data, as seen in Fig. 24, shows that Configuration 1 had much higher UHC levels. The reactions from hydrocarbons to

  4. Internal combustion engine using premixed combustion of stratified charges

    Science.gov (United States)

    Marriott, Craig D.; 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.

  5. 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.

  6. Analysis of the chemical and physical properties of combustion aerosols: Properties overview

    Science.gov (United States)

    Aerosol chemical composition is remarkably complex. Combustion aerosols can comprise tens of thousands of organic compounds and fragments, refractory carbon, metals, cations, anions, salts, and other inorganic phases and substituents [Hays et al., 2004]. Aerosol organic matter no...

  7. Internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.L.

    1977-07-01

    Current worldwide production of internal combustion piston engines includes many diversified types of designs and a very broad range of sizes. Engine sizes range from a few horsepower in small mobile units to over 40,000 brake horsepower in large stationary and marine units. The key characteristics of internal combustion piston engines considered appropriate for use as prime movers in Integrated Community Energy Systems (ICES) are evaluated. The categories of engines considered include spark-ignition gas engines, compression-ignition oil (diesel) engines, and dual-fuel engines. The engines are evaluated with respect to full-load and part-load performance characteristics, reliability, environmental concerns, estimated 1976 cost data, and current and future status of development. The largest internal combustion piston engines manufactured in the United States range up to 13,540 rated brake horsepower. Future development efforts are anticipated to result in a 20 to 25% increase in brake horsepower without increase in or loss of weight, economy, reliability, or life expectancy, predicated on a simple extension of current development trends.

  8. 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.

  9. Situación actual de la cirugía de la columna vertebral degenerativa aplicada al manejo del dolor lumbar crónico: Estenosis de canal. Discopatia degenerativa, resultados basados en la evidencia científica Present state of degenerative back surgery and its implications in the management of chronic lumbar pain, canal stenosis and degenerative disk disease: Evidence based outcomes

    Directory of Open Access Journals (Sweden)

    F. J. Robaina

    2006-04-01

    strong evidence indicating that complex and demanding spine surgery where different instrumentation is used, is not more effective than a simple, safer and cheaper posterolateral fusion without instrumentation. Recently, the literature published in this field, is showing us a tendency to use again "minimally invasive techniques", abandon transpedicular fusions, and indicating clearly that we must apply the knowledge based on the scientific evidence accumulated at least along the last 20 years. In conclussion, based in the modern information, we must recomend the abandon of the instrumented pathway in a great number of present indications for spine surgery, and look for new management strategies in the field of rehabilitation and conservative treatments correctly apply, using before the decompresive and instrumented surgery all the intervention-al techniques that are presently offer in the field of modern chronic pain treatment.

  10. Application of Fractal Grids in Industrial Low-Swirl combustion

    NARCIS (Netherlands)

    Thij, ten G.D.; Verbeek, A.A.; Meer, van der T.H.

    2016-01-01

    Fractal-grid-generated turbulence is a successful technique to significantly increase the reaction rate in the center of a low-swirl flame. Previous results (Verbeek et al. Combust. Flame 162(1), 129–143, 2015) are promising, but the experiments are only performed using natural gas at a single equiv

  11. Combustion reaction of Ti–Al–C–N system

    Indian Academy of Sciences (India)

    Yunchao Mu; Baoyan Liang

    2013-08-01

    The combustion reaction of Ti–Al–C–N system was investigated by using Ti powders and one CN precursor powder as reactant powder blends. The reactant powder blends ratio was adjusted to obtain different materials. The phase composition of the samples was investigated by X-ray diffraction (XRD). The microstructure of the samples was observed by scanning electron microscopy (SEM). The result showed that Ti2Al(C,N)–TiAl, AlN–Ti(C,N) and Ti3Al(C,N)2–TiC composites can be fabricated by changing the reactant powder blends ratio.

  12. Post combustion in converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasilasie, H.; Holappa, L.

    1997-12-31

    The purpose of this work is to study the fundamentals of post combustion and the effect of different process parameters on the post combustion ratio (PCR) and heat transfer efficiency (HTE) in converter steelmaking process. The PCR and HTE have been determined under normal operating conditions. Trials assessed the effect of lance height, vessel volume, foaming slag and pellet additions on PCR and HTE. Based on enthalpy considerations, post combustion of CO gas is regarded as one of the most effective means of increasing the heat supply to the BOP. The thermodynamic study of gas-metal-slag reactions gives the limiting conditions for post combustion inside the converter reactor. Different process parameters influencing both thermodynamic equilibria and kinetic conditions can greatly affect the post combustion ratio. Different features of converter processes as well smelting reduction processes utilizing post combustion have been reviewed. (orig.) SULA 2 Research Programme; 26 refs.

  13. 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....

  14. 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

  15. The modes of gaseous combustion

    CERN Document Server

    Rubtsov, Nickolai M

    2016-01-01

    This book provides an analysis of contemporary problems in combustion science, namely flame propagation, detonation and heterophaseous combustion based on the works of the author. The current problems in the area of gas combustion, as well as the methods allowing to calculate and estimate limiting conditions of ignition, and flame propagation on the basis of experimental results are considered. The book focuses on the virtually inaccessible works of Russian authors and will be useful for experienced students and qualified scientists in the area of experimental studies of combustion processes.

  16. 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

  17. 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.

  18. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the...

  19. Active Combustion Control Valve Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past decade, research into active combustion control has yielded impressive results in suppressing thermoacoustic instabilities and widening the operational...

  20. Basic Aerodynamics of Combustion Chambers,

    Science.gov (United States)

    1981-05-20

    8217, tie imnrulse foree eyuilibr-um c’ the bomd’~ leye - is 173 pv-:irJ p~76vJbK 2sO) IL !-. = Zn pT -- a , bV T. z -,,r y.re C era 3oia * ~~I" onc art-=e...heat by combustion all have very large influences on the capabilities of a combustion chamber. A yellow- colored flame represents diffusion combustion in...the wakes of fuel droplets. Blue- colored flames represent gaseous combustion of evaporated vapors which have already left the fuel droplets. The

  1. Physicochemical characterization of fine particles from small-scale wood combustion

    Science.gov (United States)

    Lamberg, Heikki; Nuutinen, Kati; Tissari, Jarkko; Ruusunen, Jarno; Yli-Pirilä, Pasi; Sippula, Olli; Tapanainen, Maija; Jalava, Pasi; Makkonen, Ulla; Teinilä, Kimmo; Saarnio, Karri; Hillamo, Risto; Hirvonen, Maija-Riitta; Jokiniemi, Jorma

    2011-12-01

    Emissions from small-scale wood combustion appliances are of special interest since fine particles have been consistently associated with adverse health effects. It has been reported that the physicochemical characteristics of the emitted particles affect also their toxic properties but the mechanisms behind these phenomena and the causative role of particles from wood combustion sources are still mostly unknown. Combustion situations vary significantly in small-scale appliances, especially in batch combustion. Combustion behaviour is affected by fuel properties, appliance type and operational practice. Particle samples were collected from six appliances representing different combustion situations in small-scale combustion. These appliances were five wood log fuelled stoves, including one stove equipped with modern combustion technology, three different conventional combustion appliances and one sauna stove. In addition, a modern small-scale pellet boiler represented advanced continuous combustion technology. The aim of the study was to analyze gas composition and fine particle properties over different combustion situations. Fine particle (PM 1) emissions and their chemical constituents emerging from different combustion situations were compared and this physicochemical data was combined with the toxicological data on cellular responses induced by the same particles (see Tapanainen et al., 2011). There were significant differences in the particle emissions from different combustion situations. Overall, the efficient combustion in the pellet boiler produced the smallest emissions whereas inefficient batch combustion in a sauna stove created the largest emissions. Improved batch combustion with air-staging produced about 2.5-fold PM 1 emissions compared to the modern pellet boiler (50.7 mg MJ -1 and 19.7 mg MJ -1, respectively), but the difference in the total particulate PAH content was 750-fold (90 μg MJ -1 and 0.12 μg MJ -1, respectively). Improved batch

  2. Da antropologia à antropologia aplicada ou a afirmação da antropologia no Norte de Portugal

    OpenAIRE

    2014-01-01

    A antropologia aplicada diferenciou a antropologia no Norte de Portugal desde os anos 1990. No artigo realizamos uma análise desse processo de diferenciação e afirmação na oferta educativa do ensino superior do Norte de Portugal.

  3. Optimisation d'une nanotechnologie liée à la post combustion automobile : étude par EXAFS, RMN & DRX de catalyseurs industriels Zn/Al2O3

    Science.gov (United States)

    Bazin, D.; Revel, R.; Klur, I.; Pourpoint, A.

    2002-07-01

    In this paper, we report a structural characterisation of an industrial catalyst conducted through the combined use of different characterisation techniques i.e. ^{27}Al Nuclear Magnetic Resonance (NMR), X-Ray Diffraction (XRD) and High Resolution Transmission Electronic Microscopy (HRTEM). The usual characterisation techniques help to restrict the problem but do not precisely show the structure of the supported system "Zn"/Al2O3. For example, ^{27}Al NMR shows the occupation of tetrahedral site by zinc through a modification of the occupation of tetrahedral and octahedral site by aluminium atoms. Unfortunately this technique is not able to determine the size of the zinc based metal oxide cluster. A more appropriate technique, such as X-ray absorption spectroscopy is thus necessary. In fact, we show that only the complete set of data leads to major information regarding the cation distribution as well as the electronic state of the metal atoms. Nous présentons une étude de matériaux nanodivisés industriels initiée à l'aide de techniques de caractérisation classiques (Microscopie électronique haute résolution, Résonance Magnétique Nucléaire, Diffraction des rayons X) et affinée par une technique spécifique au rayonnement synchrotron, la spectroscopie d'absorption X. Le catalyseur industriel est obtenu par dispersion à l'échelle atomique d'atomes de zinc à la surface d'une yc alumine de grande surface spécifique (> 200m^2/g). Le fait qu'une similarité structurale existe entre le support et le composé défini obtenu par insertion du cation dans la matrice rend quasi-inopérante la DRX classique. La RMN de l'aluminium par contre constitue une technique de choix puisque l'occupation par le zinc de sites tétraédriques se traduit par l'occupation plus conséquente de sites octaédriques par l'aluminium. Néanmoins, la taille des cristallites de "ZnAl2O4", les possibilités d'inversion (limitées ici car le zinc occupe préférentiellement les sites t

  4. Combustion Branch Website Development

    Science.gov (United States)

    Bishop, Eric

    2004-01-01

    The NASA combustion branch is a leader in developing and applying combustion science to focused aerospace propulsion systems concepts. It is widely recognized for unique facilities, analytical tools, and personnel. In order to better communicate the outstanding research being done in this Branch to the public and other research organization, a more substantial website was desired. The objective of this project was to build an up-to-date site that reflects current research in a usable and attractive manner. In order to accomplish this, information was requested from all researchers in the Combustion branch, on their professional skills and on the current projects. This information was used to fill in the Personnel and Research sections of the website. A digital camera was used to photograph all personnel and these photographs were included in the personnel section as well. The design of the site was implemented using the latest web standards: xhtml and external css stylesheets. This implementation conforms to the guidelines recommended by the w3c. It also helps to ensure that the web site is accessible by disabled users, and complies with Section 508 Federal legislation (which mandates that all Federal websites be accessible). Graphics for the new site were generated using the gimp (www.gimp.org) an open-source graphics program similar to Adobe Photoshop. Also, all graphics on the site were of a reasonable size (less than 20k, most less than 2k) so that the page would load quickly. Technologies such as Macromedia Flash and Javascript were avoided, as these only function on some clients which have the proper software installed or enabled. The website was tested on different platforms with many different browsers to ensure there were no compatibility issues. The website was tested on windows with MS IE 6, MSIE 5 , Netscape 7, Mozilla and Opera. On a Mac, the site was tested with MS IE 5 , Netscape 7 and Safari.

  5. A thermochemical pathway for controlled synthesis of AlN nanoparticles in non-isothermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nersisyan, Hayk H. [Department of Nanomaterials Engineering, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); RASOM, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Yoo, Bung Uk [Graduate School of Energy Science and Technology, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Kab Ho [Department of Nanomaterials Engineering, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Jong Hyeon, E-mail: jonglee@cnu.ac.kr [Department of Nanomaterials Engineering, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Graduate School of Energy Science and Technology, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); RASOM, Chungnam National University, 79 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

    2015-03-20

    Highlights: • A non-isothermal combustion process was developed for synthesizing AlN nanoparticles. • Temperature-time profiles and combustion parameters were recorded and discussed. • AlN nanoparticles (50–200 nm) with a specific surface of 7.9–20.8 m{sup 2}/g were prepared. • The thermochemical mechanism of AlN formation in the combustion wave was clarified. - Abstract: The synthesis of AlN nanoparticles in non-isothermal high-temperature conditions was developed. The process involved Al{sub 2}O{sub 3}–Mg–NH{sub 4}Cl mixtures preparation and combustion in nitrogen atmosphere. Temperature profiles in the combustion waves were recorded by thermocouples, and the values of combustion temperature and wave velocity were determined from the recorded profiles. The existence of two independed combustion regimes with maximum temperatures of about 850 °C and 1400–1600 °C were revealed based on concentrations of NH{sub 4}Cl. AlN nanocrystals were obtained and investigated by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller surface area. AlN nanocrystals prepared under non-isothermal combustion process were comprised well distributed multi-faceted particles with an average size of 50–200 nm. The chemical reactions in the combustion wave were discussed and a possible thermochemical pathway for the synthesis of AlN nanoparticles was proposed.

  6. Optimización por colonia de hormigas aplicada al problema de planeamiento de la transmisión

    Directory of Open Access Journals (Sweden)

    Ricardo Andrés Bolaños

    2009-11-01

    Full Text Available Este artículo propone un Método de Optimización por Colonia de Hormigas para resolver el sub-problema de inversión existente dentro del Problema de Planeamiento de la Expansión de la Transmisión de Sistemas Eléctricos de Potencia. El problema operativo de Programación Lineal es resuelto mediante un Método de Puntos Interiores de Alto Orden. Adicionalmente, se implementa otro Método de Puntos Interiores para Programación No Lineal cuya solución relajada es usada como índice de sensibilidad asociado a la escogencia de una línea candidata. Estos índices de sensibilidad son calculados una única vez durante todo el proceso iterativo. Adicionalmente, dentro del Algoritmo de Optimización por Colonia de Hormigas, se propone un método de dos etapas para la construcción de una alternativa de solución. La metodología propuesta se valida con los sistemas de prueba IEEE de 24 y 6 nodos./This paper proposes an Ant Colony Optimization method to solve the investment problem for the Transmission Expansion Planning Problem for Electrical Power Systems. Operative problem of Linear Programming is solved trough a High Order Interior Point Method. Moreover, the solution of a Non Linear Interior Point Method is used as a sensitivity index to initialize pheromone matrix used in the Ant Colony Algorithm, where is proposed a method with two stages to obtain a solution. The methodology is tested on the 24 and 6 Bus IEEE systems.

  7. Las incumbencias del Contador Público aplicadas al desarrollo de las Pymes de la ciudad de Mar del Plata

    OpenAIRE

    Álvarez, Federico

    2012-01-01

    Las primitivas pequeñas empresas no necesitaban contadores universitarios. Sus necesidades eran cubiertas por “tenedores de libros”, quienes eran responsables de asentar ordenada y claramente los bienes y las deudas del empresario de la época. El objetivo era analizar e informar sobre lo que había ocurrido. Las crecientes innovaciones tecnológicas fueron aumentando la cantidad de bienes producidos y, por lo tanto, la demanda creciente originó la formación de un número mayor de empresas. En nu...

  8. COMUNICACIÓN APLICADA AL MANEJO DE CRISIS Y CONFLICTOS: UN COMPONENTE POSIBLE DE LOS POSTGRADOS GERENCIALES

    Directory of Open Access Journals (Sweden)

    Rocio Belandria Cerdeira

    2008-11-01

    Full Text Available El objetivo inicial de esta investigación es analizar la comunicación como componente de los programas de postgrado del área gerencial. El estudio comparativo se realizó sobre programas de postgrado en Venezuela. Se presentan resultados de campo y teóricos que explican la importancia de la formación en comunicación en los postgrados gerenciales para el afrontamiento de las crisis y los conflictos.

  9. El Signo (Tipo)gráfico como herramienta aplicada al arte. Una aportación personal

    OpenAIRE

    Esgueva López, María Victoria

    2011-01-01

    Es un hecho fehaciente que numerosos artistas recurren a la tipografía y hacen uso de ella considerándola como un recurso más de la expresión plástica. A partir del siglo XX, el signo tipográfico ha tenido una presencia más que destacada en el Arte, esta presencia se ha ido afianzando progresivamente desde la pluralidad, en la producción de algunos artistas contemporáneos. Siguiendo esa dirección, este trabajo pretende desarrollar el estudio del signo tipográfico desde el ámbito artístico, te...

  10. Programación lineal aplicada al cálculo plástico elemental de estructuras lineales

    Directory of Open Access Journals (Sweden)

    Antón Corrales, J. M.

    1970-06-01

    Full Text Available A method is described for elementary calculations of linear structures, under non elastic conditions, and subjected to point loads. The method involves the use of Simplex programs, which are already available for any scientific computer. The result gives either a factor of safety for a structure that has already been designed, or else an optimum design for given conditions. The calculation is very short for one loading system, and less so, if several loading conditions are assumed. The method can be further improved, thus rendering its use even more simple.Expone este artículo un método para hacer los cálculos plásticos elementales de estructuras lineales con cargas puntuales por medio de programas Simplex, ya disponibles en cualquier ordenador científico, dando como resultado, sea un coeficiente de seguridad de una estructura ya dimensionada, sea una optimización de la misma. El cálculo es muy corto con un caso de cargas, y menos con varios casos de cargas. El método admite perfeccionamientos, que pueden hacer todavía más elemental su introducción en computador.

  11. La noción de infinitud aplicada al movimiento : la tesis cratiliana de la total inestabilidad

    OpenAIRE

    Pajón Leyra, Ignacio

    2009-01-01

    The notion of infinity has been applied to very varied fields of study throughout the History of Greek Philosophy. Perhaps the least known among them continues to be its application to the phenomenon of motion. The question of Becoming occupied the better part of the philosophical inquiries of the 5th and 4th centuries BC, as they were greatly influenced by the thought of authors such as Heraclitus, Parmenides, Zenon, Democritus or Aristotle, among others. Yet perhaps the name to which we oug...

  12. La Programación Neurolingüística aplicada al aula. El Aprendizaje dinámico

    OpenAIRE

    Jimenez, María Yolanda

    2012-01-01

    El presente trabajo consta de dos partes. La Primera Parte consiste en una exposición (dentro de las limitaciones que un Trabajo de este tipo impone) de las premisas y fundamentos prácticos de la Programación Neurolingüística, así como de sus estrategias y herramientas. La Segunda Parte consiste en una recopilación significativa de distintas técnicas para trabajar con los diferentes alumnos en el aula. Se trata de una propuesta de actividades inspiradas en el “aprendizaje dinámico”, término a...

  13. La investigación cualitativa aplicada al estudio del nacionalismo: el discurso neoespañolista

    OpenAIRE

    HELENA BÉJAR

    2007-01-01

    El siguiente artículo es parte de una investigación cualitativa de diecisiete grupos sobre «Nacionalismo y sentido de pertenencia: nacionalismo español, catalán y vasco». Se analiza aquí lo que llamo discurso neoespañolista, caracterizado por establecer una crítica del nacionalismo tanto en su versión españolista como en la de las naciones sin Estado y la apertura a un discurso cívico-republicano. Dicho discurso reivindica la noción de ciudadanía frente a la de pertenencia, propia del lenguaj...

  14. Modelización aplicada al diseño de sistemas de control en el horno alto

    Directory of Open Access Journals (Sweden)

    Rosal, R.

    1995-06-01

    Full Text Available The production of pig iron in blast furnaces resists automatic control strategies due to the lack of knowledge about physical and chemical phenomena taking place inside the reactor. High dimensions lead to important dead times and lags. As a consequence it is very difficult to quantify control actions from actual process measurements. A simplified multizonal mathematical model has been proposed that allowed the description of a given blast furnace excluding hearth. Parameters underlying the model have been identified and, under appropriate assumptions, temperature and composition profiles have been established. The analysis of model predictions has been illustrated with steady-state responses to typical control actions.

    El control del proceso de fabricación de arrabio en hornos altos resulta complejo debido a las condiciones de operación: conocimiento incompleto de la quimicofísica de los procesos que tienen lugar en el interior del homo, grandes dimensiones del reactor que se traducen en tiempos muertos considerables y constantes de tiempo elevadas que provocan una gran inercia a las acciones de control. En este trabajo, se ha planteado un modelo matemático por zonas que permite describir el comportamiento del homo excepto el crisol, se han identificado sus parámetros y se ha obtenido el perfil interno de temperaturas y composiciones. El análisis del modelo permite predecir los efectos de un cambio en cualquier variable del sistema así como desarrollar un algoritmo de control automático.

  15. Nuevas tecnologías aplicadas al sector turístico en la Región de Murcia

    OpenAIRE

    Villalba Trujillo, Raquel; Martínez Caro, Laura; Martínez María Dolores, Soledad María

    2013-01-01

    Las Tecnologías de la Información y las Comunicaciones han supuesto una revolución en el sector turístico, que avanza y cambia diariamente. La implantación de estas nuevas tecnologías permite un acceso rápido a la información turística, localización o servicio de guías digitales. Dado la amplia oferta histórica-patrimonial que ofrece la ciudad de Cartagena y con le fin de impulsar el turismo de una zona, creemos que es necesario que se adapten los recursos turísticos de la ciudad a las nuevas...

  16. Un agricultor de nuestros días: la ultima tecnología aplicada al campo.

    OpenAIRE

    2002-01-01

    En Vida Rural hemos querido imaginar cómo puede ser la actividad agraria dentro de unos años, cuando las tecnologías punteras que ahora se están desarrollando sean una realidad comercial. Esta historia de ficción científica (que no ciencia ficción, ya que se basa en tecnologías reales y no en equipos fruto de nuestra imaginación) no es sólo un ejercicio literario, sino que quiere reflejar cómo la tecnología puede mejorar y ayudar a nuestros agricultores y en qué terrenos la investigación agra...

  17. Tecnologías de la web semántica aplicadas al modelado del agarre de objetos

    OpenAIRE

    Collado Valle, Francisco Javier

    2014-01-01

    La investigación presenta un modelo de datos para representar agarres de objetos que será una parte de un sistema formado por un módulo de visión artificial y un brazo con una mano robótica. El uso de manos robóticas hace que aparezca la necesidad de desarrollar un modelo de datos que permita no solo almacenar los agarres sino además poder relacionarlos con los objetos. Los objetos además deben ser reconocidos por el sistema de visión artificial, lo cuál hace que sea necesario almacenar los d...

  18. Zonificación agroclimática de Papadakis aplicada al estado de Sinaloa, México

    Directory of Open Access Journals (Sweden)

    Israel Velasco

    2010-01-01

    Full Text Available La influencia del relieve produce una amplia variación en los diversos climas, más que la latitud. El sistema de Köppen, uno de los más usados, es del tipo físico, y da una excelente aproximación a las condiciones reales, que en mucho se reflejan por la vegetación natural, pero no considera en toda su dimensión la interrelación agua-suelo-planta cultivada-atmósfera, siendo que estos factores influyen tanto en la vegetación tanto natural como cultivada. Los periodos con temperaturas congelantes o con riesgo de heladas, y la duración de los meses o periodos secos son determinantes para la agricultura, tanto la de autoconsumo como la comercial. Estos aspectos sí los considera el método de Papadakis, lo que permite evaluar la potencialidad y limitaciones de las diversas zonas climáticas, en términos de los cultivos. En este trabajo se hace una aplicación del método a una amplia región del noroeste de México, de gran importancia agrícola, y los resultados convergen en que los grupos climáticos existentes son: 1.4: sabana continental 1.5: tropical semiárido 1.9: tropical con invierno fresco 2.3: tierra fría media 4.2: subtropical continental 4.3: semitropical continental

  19. La psicología aplicada en España

    OpenAIRE

    Sáiz Roca, Milagros; Sáiz Roca, Dolores

    1998-01-01

    Nuestro artículo ofrece una panorámica del inicio y desarrollo de la psicología aplicada en España. En él veremos cómo la aplicación de la psicología a los diferentes ámbitos -educativo, militar, jurídico, industrial, etc.- surgió en España de una forma casi paralela a otros países; sin embargo, tuvo una diferente demanda social y faltó su desarrollo en el seno de la universidad. Ante la ausencia de un marco universitario fueron los institutos de orientación profesional quienes generaron un p...

  20. Caos, complexidade e Lingüística Aplicada: diálogos transdisciplinares

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Soares Martins

    2007-01-01

    Full Text Available Neste texto, apresentamos um panorama de estudos na área da Lingüística Aplicada que discutem questões relativas ao processo de desenvolvimento de segunda língua, bem como aspectos relacionados aos ambientes interacionais de aprendizagem na perspectiva das teorias do Caos e Complexidade. Para isso, discutimos as principais noções da perspectiva da complexidade, retomando alguns aspectos da física clássica e contemporânea.In this paper, we present a panorama of studies in the area of Applied Linguistics that discuss questions regarding second language development as well as aspects related to interactional learning environments in the light of Chaos and Complexity theories. To accomplish this, we discuss the main notions of complexity through the rethinking of some aspects of classic and contemporary physics.

  1. Ensaios sobre desenvolvimento econômico: uma abordagem neo-schumpeteriana aplicada à economia brasileira

    OpenAIRE

    Daniel de Souza Coelho

    2010-01-01

    A análise de contabilidade do crescimento aplicada ao Brasil, no período de 1950 a 2007, indica que o crescimento brasileiro não é explicado de forma satisfatória pelas teorias que tratam o progresso técnico como exógeno. Usando o modelo neo-schumpeteriano, explorou-se o papel da competição de mercado no crescimento da produtividade e do esforço inovativo das firmas usando as bases de dados da PAEP/SEADE e da PIA/IBGE. A importância do tamanho da firma nessas análises estimulou a investigação...

  2. Ciencia básica y ciencia aplicada Basic science and applied science

    OpenAIRE

    Ruy Pérez-Tamayo

    2001-01-01

    En el contexto de una intervención en el Foro de Consulta Democrática de la Coordinación de los Institutos Nacionales de Salud sobre Enseñanza e Investigación en Salud, realizado en el Instituto Nacional de Cardiología Ignacio Chávez, se hace una revisión crítica de la clasificación convencional de la ciencia en básica y aplicada; además, se analiza lo que deberían ser la enseñanza y la investigación en salud. Para apoyar su propia clasificación de la ciencia en "bien hecha", la cual "genera ...

  3. 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

  4. 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...

  5. 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.

  6. Uma breve História da Computação Aplicada no Brasil

    Directory of Open Access Journals (Sweden)

    Adelaine Gelain

    2014-11-01

    Full Text Available A área de pesquisa da Computação Aplicada (CA no Brasil, em fase de consolidação, tem crescido em importância graças à sua relação com outras áreas. Por sua “jovialidade”, pouco se tem analisado sobre a forma como se faz pesquisas nessa área. A Revista Brasileira de Computação Aplicada (RBCA é uma publicação representativa desse foco que foi criada há pouco tempo. Então, para se ter uma visão das pesquisas na área de CA analisou-se a produção registrada na RBCA. Três análises foram feitas: quanto aos paradigmas científicos predominantes, estilo de maturidade e abordagem de pesquisa das publicações dos últimos cinco anos. Um checklist foi concebido para facilitar a análise mais subjetiva – do paradigma. Todos os artigos foram avaliados ao menos duas vezes, sendo que a maioria sofreu três avaliações distintas. As 501 avaliações em três rodadas permitiu caracterizar a produção como majoritariamente tecnocrática, usando estilos de maturidade iniciais e abordagens desenvolvimentista e descritiva. Esses elementos sugerem que os pesquisadores da área adotam o viés das Engenharias, o que é razoável considerando o aspecto “aplicado”. Entretanto, para a CA consolidar-se como uma ramificação da Ciência da Computação (CC, vê-se importante que os pesquisadores da CA utilizem metodologias científicas de maior credibilidade.

  7. Inteligência Competitiva: metodologias aplicadas em empresas brasileirasInteligencia Competitiva: metodologías aplicadas en las empresas brasileñas

    Directory of Open Access Journals (Sweden)

    Mônica Erichsen Nassif

    2012-01-01

    Full Text Available Introdução: Apresenta um panorama acerca da Inteligência Competitiva no contexto das organizações brasileiras. Objetivo: Investiga a existência de metodologias de Inteligência Competitiva aplicadas a organizações nacionais e multinacionais de diferentes segmentos de mercado. Metodologia: Revisão de literatura nacional e internacional – envolvendo o status quo da atividade de Inteligência Competitiva no mundo – e cujo conteúdo foi confrontado com os resultados obtidos em entrevistas realizadas em 13 organizações nacionais e multinacionais com atuação no Brasil, no período de dezembro de 2010 a abril de 2011. Resultados: No artigo foram analisados os diferentes objetivos e experiências de Inteligência Competitiva em organizações envolvendo diferentes práticas para a projeção de cenários, análise de conteúdos provenientes de mídias e monitoramento do ambiente geral e setorial das organizações. A pesquisa apontou ainda as principais fontes e produtos de informação, perfil dos participantes e ferramentas utilizadas para a prática de Inteligência Competitiva no ambiente organizacional brasileiro. Conclusões: Embora as organizações adotem metodologias relativamente similares de Inteligência Competitiva, essa atividade apresenta objetivos distintos, afeitos tanto ao enfoque estratégico, quanto aos enfoques mercadológico, comercial e de vendas, prevalecendo o primeiro. O aspecto estratégico também está refletido nos modelos de subordinação hierárquica dominante das áreas de Inteligência Competitiva.

  8. Recovery of alumina from circulating fluidized bed combustion Al-rich fly ash using mild hydrochemical process%温和水热法从循环流化床粉煤灰中回收氧化铝

    Institute of Scientific and Technical Information of China (English)

    杨权成; 马淑花; 郑诗礼; 张然

    2014-01-01

    开发一种温和水热法从电厂排放的粉煤灰中提取氧化铝。当处理氧化铝和二氧化硅的质量比(A/S)为0.78、氧化铝含量为32.43%的粉煤灰时,在NaOH浓度45%、初始苛性比(铝酸钠溶液中氧化钠和氧化铝的摩尔比)25、氧化钙和粉煤灰中二氧化硅的摩尔比1.1、液固体积质量比9、反应温度280°C、停留时间1 h的条件下,氧化铝的提取率可达到92.31%。此外,通过结构和化学分析,对氧化铝的浸出机理进行了研究。结果表明,经过碱浸后,含硅的主要物相为理论铝硅比为0的NaCaHSiO4。%To utilize CFBC Al-rich fly ash, a mild hydrochemical extraction process was investigated for recovery of alumina. An alumina extraction efficiency of 92.31%was attained using a 45%NaOH solution, an original caustic ratio (molar ratio of Na2O to Al2O3 in the sodium aluminate solution) of 25, a molar ratio of CaO to SiO2 in the fly ash of 1.1, a liquid volume to solid mass ratio of 9, a reaction temperature of 280 °C, and a residence time of 1 h when treating fly ash with an alumina to silica mass ratio (A/S) of 0.78 and an alumina content of 32.43%. Additionally, the alumina leaching mechanism was explored via structural and chemical analysis, which revealed that after alkaline digestion, the main solid phase containing silica was NaCaHSiO4 with a theoretical A/S of zero.

  9. Sub-grid scale combustion models for large eddy simulation of unsteady premixed flame propagation around obstacles.

    Science.gov (United States)

    Di Sarli, Valeria; Di Benedetto, Almerinda; Russo, Gennaro

    2010-08-15

    In this work, an assessment of different sub-grid scale (sgs) combustion models proposed for large eddy simulation (LES) of steady turbulent premixed combustion (Colin et al., Phys. Fluids 12 (2000) 1843-1863; Flohr and Pitsch, Proc. CTR Summer Program, 2000, pp. 61-82; Kim and Menon, Combust. Sci. Technol. 160 (2000) 119-150; Charlette et al., Combust. Flame 131 (2002) 159-180; Pitsch and Duchamp de Lageneste, Proc. Combust. Inst. 29 (2002) 2001-2008) was performed to identify the model that best predicts unsteady flame propagation in gas explosions. Numerical results were compared to the experimental data by Patel et al. (Proc. Combust. Inst. 29 (2002) 1849-1854) for premixed deflagrating flame in a vented chamber in the presence of three sequential obstacles. It is found that all sgs combustion models are able to reproduce qualitatively the experiment in terms of step of flame acceleration and deceleration around each obstacle, and shape of the propagating flame. Without adjusting any constants and parameters, the sgs model by Charlette et al. also provides satisfactory quantitative predictions for flame speed and pressure peak. Conversely, the sgs combustion models other than Charlette et al. give correct predictions only after an ad hoc tuning of constants and parameters.

  10. 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.

  11. Manual para la construcción e instalación de tanques de doble pared para almacenamiento de combustible en estaciones de servicio

    OpenAIRE

    Diaz Lopez, Darwin Richard; Helguero, Manuel

    2009-01-01

    Esta tesis de grado ha sido desarrollada para dar una solución técnica y económica en el procedimiento de la construcción e instalación de tanques enterrados para almacenamiento de combustible en Estaciones de Servicio Automotrices; procedimientos basados en normas aplicadas dentro de este campo y lo contendrá como manual practico. En el país no existe una normativa específica para procedimiento en construcción, por lo que se ha visto la necesidad de crear un manual que cuente con la infor...

  12. 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...

  13. Mission Success for Combustion Science

    Science.gov (United States)

    Weiland, Karen J.

    2004-01-01

    This presentation describes how mission success for combustion experiments has been obtained in previous spaceflight experiments and how it will be obtained for future International Space Station (ISS) experiments. The fluids and combustion facility is a payload planned for the ISS. It is composed of two racks: the fluids Integrated rack and the Combustion INtegrated Rack (CIR). Requirements for the CIR were obtained from a set of combustion basis experiments that served as surrogates for later experiments. The process for experiments that fly on the ISS includes proposal selection, requirements and success criteria definition, science and engineering reviews, mission operations, and postflight operations. By following this process, the microgravity combustion science program has attained success in 41 out of 42 experiments.

  14. Sulphur poisoning and regeneration of precious metal catalysed methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.M.; Dupont, V.A.; Fullerton, D.J.; Ross, A.B.; Westwood, A.V.K. [Department of Fuel and Energy, SPEME, University of Leeds, Leeds LS2 9JT (United Kingdom); Brydson, R. [Department of Materials, SPEME, University of Leeds, Leeds LS2 9JT (United Kingdom); Nasri, N.S. [Gas Engineering Department, Universiti Teknologi Malaysia, 81310 Skudai Johor (Malaysia)

    2003-07-01

    In many of the applications of catalytic combustion small amounts of sulphur compounds are present in the feed gas. In the case of natural gas combustion, and solid fuel syngas, the sulphur compounds are in reduced forms. The present work investigates the influence of small quantities of reduced sulphur compounds on the combustion of methane over alumina-supported precious metal catalysts. The kinetics of the methane combustion in the presence of low concentrations of a mixture of sulphur compounds (ethyl mercaptan, methyl mercaptan, carbonyl sulphide and hydrogen sulphide) are compared with those in the absence of sulphur compounds. The ease of regeneration of the poisoned catalysts, via low temperature reduction with hydrogen, is also examined. In the conditions studied all catalysts have reduced activity in the presence of the sulphur-based gas mixture, but Pt/Al{sub 2}O{sub 3} and Rh/Al{sub 2}O{sub 3} are more strongly poisoned than Pd/Al{sub 2}O{sub 3}. Qualitative studies using gas chromatography with atomic emission detection of the exhaust gases, and FTIR spectroscopy of the spent Rh/Al{sub 2}O{sub 3} catalyst, suggest that the catalysts experience a mixture of reduced and oxidised species under reaction conditions, and that sulphating of the support occurs. The regeneration step facilitates metal mobility and meets with varying success depending upon the metal. Pt/Al{sub 2}O{sub 3} in particular is difficult to regenerate by reduction in hydrogen (400C for 0.5h), and agglomeration is observed by TEM. Rh/Al{sub 2}O{sub 3} regenerates well, and low metal particle size is maintained. A non-linear deactivation model is tested to separate sulphur-induced deactivation from 'natural' deactivation in the reaction mixture and preliminary results are presented.

  15. Effect of Metal Additives on the Combustion Characteristics of High-Energy Materials

    Directory of Open Access Journals (Sweden)

    Korotkikh Alexander

    2016-01-01

    Full Text Available Thermodynamic calculation of combustion parameters and equilibrium composition of HEMs combustion products showed, that at the increase of aluminum powder dispersity the specific impulse and combustion temperature of solid propellants are reduced due to the decrease of the mass fraction of active aluminum in particles. Partial or complete replacement of aluminum by metal powder (B, Mg, AlB2, Al\\Mg alloy, Fe, Ti and Zr in HEMs composition leads to the reduce of the specific impulse and combustion temperature. Replacement of aluminum powder by boron and magnesium in HEM reduces the mass fraction of condensed products in the combustion chamber of solid rocket motor. So, for compositions HEMs with boron and aluminum boride the mass fraction in chamber is reduced by 24 and 36 %, respectively, with respect to the composition HEMs with Al powder. But the mass fraction of CCPs in the nozzle exit increases by 13 % for HEMs with aluminum boride due to the formation of boron oxide in the condensed combustion products. Partial replacement of 2 wt. % aluminum powder by iron and copper additives in HEM leads to the reduce of CCPs mass fraction in chamber by 4–10 % depending on the aluminum powder dispersity duo to these metals are not formed condensed products at the HEMs combustion in chamber.

  16. A inserção do ensino de custos na disciplina administração aplicada à enfermagem La inserción de la enseñanza de costos en la disciplina administración aplicada a la enfermería Insertion of cost teaching in the discipline of administration applied to nursing

    Directory of Open Access Journals (Sweden)

    Ivone Maria Fonseca Francisco

    2006-03-01

    Full Text Available O objetivo deste texto foi realizar um resgate teórico sobre a traje-tória da disciplina de Admi-nistração Aplicada à Enfermagem, na graduação, ao longo da história do ensino da Enfermagem Brasi-leira, relacionando-a ao ensino de Custos. Percebemos, inseridas no ensino dessa disciplina, diversas citações diretas referentes ao tema Custos ou Economia em Saúde, desde o primeiro currículo de Enfermagem de 1890 até as Diretrizes Curriculares Nacionais do Curso de Graduação em Enfer-magem de 2001, além de citações indiretas relacionadas ao geren-ciamento, tomada de decisão, assessorias em projetos de saúde, entre outras, mas sem haver uma continuidade.Este texto tuvo como objetivo realizar un rescate teórico sobre la trayectoria de la disciplina de Administración Aplicada a la enfermería, en el pregrado, a lo largo de la historia de la enseñanza de la Enfermería Brasileña, relacionándola a la enseñanza de Costos. Percibimos, insertadas en la enseñanza de esa disciplina, diversas citaciones directas referentes al tema Costos o Economía en Salud, desde el primer currículo de Enfermería de 1890 hasta las Directivas Curriculares Nacionales del Pregrado en Enfermería del 2001, además de citaciones indirectas relacionadas al gerenciamiento, toma de decisión, asesorías en proyectos de salud, entre otras, pero sin ninguna continuidad.The objective of this text was to make theoretical rescue of the course of the undergraduate disci-pline Administration Applied to Nursing throughout the history of teaching of Nursing in Brazil, connecting it to the teaching of Costs. We noticed, inserted in the teaching of this discipline, many direct quotes related to the themes of Costs or Economics in Health, from the earliest curriculum in Nursing, dating back to 1890, to the National Curricular Policies of the Nursing Undergraduate Course, of 2001, in addition to indirect quotes related to mana-gement, decision taking, and advising in

  17. Combustion synthesis of cobalt pigments: Blue and pink

    OpenAIRE

    Mimani, T; Ghosh, Samrat

    2000-01-01

    Idiochromatic blue cobalt aluminate (CoAl2O4) and purple pyroborate Co2B2O5 were prepared by solution combustion method using corresponding metal nitrates, boric acid and carbohydrazide mixtures. Allochromatic Co2+ doped in Al2O3/ZnAl2O4 and Mg2B2O5 pigments having the same colour intensity as idiochromatic pigments were obtained similarly. All the pigments are voluminous, homogeneously coloured with a large surface area. The products are characterized by their characteristic colours, XRD, IR...

  18. The first turbulent combustion

    CERN Document Server

    Gibson, C H

    2005-01-01

    The first turbulent combustion arises in a hot big bang cosmological model Gibson (2004) where nonlinear exothermic turbulence permitted by quantum mechanics, general relativity, multidimensional superstring theory, and fluid mechanics cascades from Planck to strong force freeze out scales with gravity balancing turbulent inertial-vortex forces. Interactions between Planck scale spinning and non-spinning black holes produce high Reynolds number turbulence and temperature mixing with huge Reynolds stresses driving the rapid inflation of space. Kolmogorovian turbulent temperature patterns are fossilized as strong-force exponential inflation stretches them beyond the scale of causal connection ct where c is light speed and t is time. Fossil temperature turbulence patterns seed nucleosynthesis, and then hydro-gravitational structure formation in the plasma epoch, Gibson (1996, 2000). Evidence about formation mechanisms is preserved by cosmic microwave background temperature anisotropies. CMB spectra indicate hydr...

  19. Catalytic Combustion of Low-density-VAM on CuMnZrOx/TiO2-Al2O3/CC%CuMnZrOx/TiO2-Al2O3/CC催化燃烧低浓度VAM

    Institute of Scientific and Technical Information of China (English)

    施卫国; 郭松林; 肖素萍; 彭剑峰; 刘芳

    2014-01-01

    采用涂覆-浸渍法制备了CuMnZrOx/TiO2-Al2O/CC催化剂,测定了其对低浓度VAM催化燃烧活性.结果表明,CuMnZrOx/TiO2-Al2O3/CC催化剂具有较好的催化活性,TiO2-Al2O3涂层负载为10%,活性组分CuMnZrOx负载为3%的催化剂在VAM预热温度为381℃、空速为10000 h-1时,1%甲烷浓度的VAM转化率可达91%.

  20. Filtration combustion: Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  1. Combustion Properties of Straw Briquettes

    Directory of Open Access Journals (Sweden)

    Zhao Qing-ling

    2013-05-01

    Full Text Available The low bulk density of straw is one of the major barriers, which blocks the collection, handling, transportation and storage. Densification of biomass into briquettes/pellets is a suitable method of increasing the bulk density of biomass. Yet in the process, a tremendous amount of air is ejected from biomass grind, which brings substantial specific variation including combustion property. Among them, combustion property is critical for proper design and operation of burning facilities. Therefore, a series of tests about combustion properties of 75mm diameter corn briquettes were done. First, the combustion process (ignition, full flaming and glowing phases., precipitation of tar were investigated by a heating stove, then, Some ash sample from the muffle burner was subjected to an ash melting characteristic test. The results show the combustion of briquettes takes more time than that of raw straw from ignition to complete combustion; in order to meet complete combustion in a short time, the raw straw needs more supply air volume than briquettes under the same α value; the temperature of furnace chamber should been controlled under 900°C, which help to reduce the dark smoke, tar and slag.

  2. O DESENVOLVIMENTO DE COMPETÊNCIAS GERENCIAIS DO ENFERMEIRO NA PERSPECTIVA DE DOCENTES DE DISCIPLINAS DE ADMINISTRAÇÃO APLICADA À ENFERMAGEM

    Directory of Open Access Journals (Sweden)

    Solange Rothbarth

    2009-01-01

    Full Text Available Investigación de carácter cualitativo, cuyo objetivo fue describir cómo los profesores de asignaturas de Administración aplicada a la Enfermería perciben el desarrollo de las competencias gerenciales. Los sujetos fueron siete enfermeros profesores en seis instituciones de educación superior en Curitiba-PR, Brasil. La recolección de los datos fue entre abril y junio de 2008. La técnica usada fue la entrevista semiestructurada, siendo sometidas al análisis del contenido. Se analizaron siete categorías predeterminadas: definición de la competencia profesional, dificultades del enfermero en el ejercicio de la gestión, competencias gerenciales necesarias para el enfermero, contribución de los estudios superiores y de la práctica profesional para el desarrollo de estas competencias, alternativas para desarrollarlas o perfeccionarlas, temas que se deben abordar en programas de desarrollo gerencial y el papel de las instituciones empleadoras. Los sujetos destacan el papel relevante de los estudios superiores, del propio enfermero y de las instituciones empleadoras en el desarrollo y mejora de la capacidad de gestión.

  3. 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.

  4. On Lean Turbulent Combustion Modeling

    Directory of Open Access Journals (Sweden)

    Constantin LEVENTIU

    2014-06-01

    Full Text Available This paper investigates a lean methane-air flame with different chemical reaction mechanisms, for laminar and turbulent combustion, approached as one and bi-dimensional problem. The numerical results obtained with Cantera and Ansys Fluent software are compared with experimental data obtained at CORIA Institute, France. First, for laminar combustion, the burn temperature is very well approximated for all chemical mechanisms, however major differences appear in the evaluation of the flame front thickness. Next, the analysis of turbulence-combustion interaction shows that the numerical predictions are suficiently accurate for small and moderate turbulence intensity.

  5. Regulation possibilities of biomass combustion

    Science.gov (United States)

    Suzdalenko, Vera; Gedrovics, Martins; Zake, Maija; Barmina, Inesa

    2012-11-01

    The focus of the recent experimental research is to analyze the regulation possibilities of biomass combustion. Three possibilities were chosen as part of this research: a) biomass cofiring with propane, b) swirling flow with re-circulation zone, and c) use of a permanent magnet. The aim of the research is to provide stable, controllable and effective biomass combustion with minimum emissions. The special pilot device was created where biomass can be combusted separately and co-fired with propane. Wood pellets were used during the experiments.

  6. Combustion-gas recirculation system

    Science.gov (United States)

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  7. Influence of fuels on the morphology of undoped Y{sub 3}Al{sub 5}O{sub 12} and photoluminescence of Y{sub 3}Al{sub 5}O{sub 12}:Eu{sup 3+} prepared by a combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Kai; Zhang, Xue-Mei [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, 1295 Ding Xi Road, Shanghai 200050 (China); Graduate School of Chinese Academy of Sciences, 19A Yu Quan Road, Beijing 100039 (China); Chen, Hao-Hong; Yang, Xin-Xin; Guo, Xiangxin [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, 1295 Ding Xi Road, Shanghai 200050 (China); Zhao, Jing-Tai, E-mail: jtzhao@mail.sic.ac.cn [Key Laboratory of Transparent Opto-Functional Inorganic Materials of Chinese Academy of Sciences, Shanghai Institute of Ceramics, 1295 Ding Xi Road, Shanghai 200050 (China)

    2010-09-15

    Undoped and Eu-doped yttrium aluminum garnet nano-powders were prepared by a facile combustion method with citric acid/ethylene diamine tetraacetic acid (EDTA) as fuels and nitrates as oxidizers. The precursors and powders calcined at 1030 {sup o}C were investigated using thermogravimetric (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) surface area measurements. It was found that the powders could be indexed with a garnet structure. The grains were in shape of hemispherical with sizes between 60 nm and 100 nm. With decreasing the citric acid/EDTA ratio, the crystallite size decreased steadily and the specific surface area increased. Investigations of photoluminescence (PL) revealed that as-synthesized YAG:Eu{sup 3+} phosphor samples exhibited an orange emission band with a main peak at 591 nm under the excitation of 394 nm. As citric acid amounts increased, the quality of crystallinity became higher and the luminescent properties were monotonously enhanced.

  8. THE COMBUSTION ACTION VERIFICATION AND ESTIMATE OF COMBUSTION EFFICIENCY IN AVIATION GAS#TURBINE ENGINE COMBUSTION CHAMBERS

    OpenAIRE

    2011-01-01

    Verification results of combustion action simulating and estimate of calculation combustion efficiency that was given by simulating were shown. Mathematical model and its assumption are described. Execution calculations method was shown. Results of simulating are shown; their comparative analyses with results of experiment were executed. Accuracy of combustion action mathematical modeling by combustion efficiency in model with oneand two-stage reactions of combustion was estimated. The infere...

  9. 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

  10. 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,

  11. 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, a

  12. Compositional Simulation of In-Situ Combustion EOR: A Study of Process Characteristics

    DEFF Research Database (Denmark)

    Jain, Priyanka; Stenby, Erling Halfdan; von Solms, Nicolas

    2010-01-01

    and multidisciplinary process data. This paper extends the understanding of previous research done in this domain by performing the process simulations to study further the impact of oxidation reactions and combustion reactions of crude oils along with their saturate, aromatic, resin, and asphaltene (SARA) fractions......In order to facilitate the study of the influence of reservoir process characteristics in In-Situ combustion modeling and advance the work of Kristensen et al. in this domain; a fully compositional In-situ combustion (ISC) model of Virtual Kinetic Cell (VKC; single-cell model) for laboratory scale...... combustion simulation is used. Preceding research work primarily focused on a kinetic model that was based on six components and incorporated four chemical reactions. However, modeling of a thermal process as complex as In-situ combustion requires in-depth understanding of detailed reaction kinetics...

  13. ALS Association

    Science.gov (United States)

    ... ALS and their families in areas affected by Hurricane Harvey. Learn More The ALS Association Disaster Relief Fund ... ALS and their families in areas affected by Hurricane Harvey. Learn More Our Mission To discover treatments and ...

  14. Expertos culturales e intervención social: tensiones y transformaciones en antropología aplicada

    Directory of Open Access Journals (Sweden)

    Enrique Jaramillo Buenaventura

    2008-12-01

    Full Text Available A partir de una breve revisión bibliográfica sobre la antropología aplicada y la antropología del desarrrollo este artículo explora algunos de los problemas teriricos y metodológicos sobre los retos y las implicaciones de pensar a la antropología como un "saber experto" parala intervención social.

  15. Combustion Process Modelling and Control

    Directory of Open Access Journals (Sweden)

    Vladimír Maduda

    2007-10-01

    Full Text Available This paper deals with realization of combustion control system on programmable logic controllers. Control system design is based on analysis of the current state of combustion control systems in technological device of raw material processing area. Control system design is composed of two subsystems. First subsystem is represented by software system for measured data processing and for data processing from simulation of the combustion mathematical model. Outputs are parameters for setting of controller algorithms. Second subsystem consists from programme modules. The programme module is presented by specific control algorithm, for example proportional regulation, programmed proportional regulation, proportional regulation with correction on the oxygen in waste gas, and so on. According to the specific combustion control requirements it is possible built-up concrete control system by programme modules. The programme modules were programmed by Automation studio that is used for development, debugging and testing software for B&R controllers.

  16. Putting combustion optimization to work

    Energy Technology Data Exchange (ETDEWEB)

    Spring, N.

    2009-05-15

    New plants and plants that are retrofitting can benefit from combustion optimization. Boiler tuning and optimization can complement each other. The continuous emissions monitoring system CEMS, and tunable diode laser absorption spectroscopy TDLAS can be used for optimisation. NeuCO's CombustionOpt neural network software can determine optimal fuel and air set points. Babcock and Wilcox Power Generation Group Inc's Flame Doctor can be used in conjunction with other systems to diagnose and correct coal-fired burner performance. The four units of the Colstrip power plant in Colstrips, Montana were recently fitted with combustion optimization systems based on advanced model predictive multi variable controls (MPCs), ABB's Predict & Control tool. Unit 4 of Tampa Electric's Big Bend plant in Florida is fitted with Emerson's SmartProcess fuzzy neural model based combustion optimisation system. 1 photo.

  17. Flameless Combustion for Gas Turbines

    Science.gov (United States)

    Gutmark, Ephraim; Li, Guoqiang; Overman, Nick; Cornwell, Michael; Stankovic, Dragan; Fuchs, Laszlo; Milosavljevic, Vladimir

    2006-11-01

    An experimental study of a novel flameless combustor for gas turbine engines is presented. Flameless combustion is characterized by distributed flame and even temperature distribution for high preheat air temperature and large amount of recirculating low oxygen exhaust gases. Extremely low emissions of NOx, CO, and UHC are reported. Measurements of the flame chemiluminescence, CO and NOx emissions, acoustic pressure, temperature and velocity fields as a function of the preheat temperature, inlet air mass flow rate, exhaust nozzle contraction ratio, and combustor chamber diameter are described. The data indicate that larger pressure drop promotes flameless combustion and low NOx emissions at the same flame temperature. High preheated temperature and flow rates also help in forming stable combustion and therefore are favorable for flameless combustion.

  18. Hybrid Combustion-Gasification Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Herbert Andrus; Gregory Burns; John Chiu; Gregory Lijedahl; Peter Stromberg; Paul Thibeault

    2009-01-07

    For the past several years Alstom Power Inc. (Alstom), a leading world-wide power system manufacturer and supplier, has been in the initial stages of developing an entirely new, ultra-clean, low cost, high efficiency power plant for the global power market. This new power plant concept is based on a hybrid combustion-gasification process utilizing high temperature chemical and thermal looping technology The process consists of the oxidation, reduction, carbonation, and calcination of calcium-based compounds, which chemically react with coal, biomass, or opportunity fuels in two chemical loops and one thermal loop. The chemical and thermal looping technology can be alternatively configured as (i) a combustion-based steam power plant with CO{sub 2} capture, (ii) a hybrid combustion-gasification process producing a syngas for gas turbines or fuel cells, or (iii) an integrated hybrid combustion-gasification process producing hydrogen for gas turbines, fuel cells or other hydrogen based applications while also producing a separate stream of CO{sub 2} for use or sequestration. In its most advanced configuration, this new concept offers the promise to become the technology link from today's Rankine cycle steam power plants to tomorrow's advanced energy plants. The objective of this work is to develop and verify the high temperature chemical and thermal looping process concept at a small-scale pilot facility in order to enable AL to design, construct and demonstrate a pre-commercial, prototype version of this advanced system. In support of this objective, Alstom and DOE started a multi-year program, under this contract. Before the contract started, in a preliminary phase (Phase 0) Alstom funded and built the required small-scale pilot facility (Process Development Unit, PDU) at its Power Plant Laboratories in Windsor, Connecticut. Construction was completed in calendar year 2003. The objective for Phase I was to develop the indirect combustion loop with CO{sub 2

  19. Combustion Enhancement of Liquid Fuels via Nanoparticle Additions: Screening, Dispersion, and Characterization

    Science.gov (United States)

    2015-06-04

    heat of combustion of mixtures of nano-sized aluminum (n-Al) and nano-sized aluminum oxide (n-Al2O3) in ethanol with a bomb calorimeter. Stable...made at 20 °C, provided by partially immersing the pycnometer in a Forma Scientific Model 2095 circulator bath . The following steps were taken: 1

  20. II SEMINARIO INTERNACIONAL EN CIENCIAS APLICADAS “Una mirada hacia la innovación y el desarrollo sostenible”

    Directory of Open Access Journals (Sweden)

    Diana Verónica Cortés-Espinosa; et. al.

    2013-12-01

    Full Text Available INTRODUCCIÓN La Química, Biología y las Matemáticas son el pilar de las ciencias aplicadas. La investigación en el área básica se ve reflejada en el desarrollo de disciplinas como las ciencias de la salud, ingenierías y ciencias ambientales. De esta forma, la integración entre la investigación básica y las ciencias aplicadas es fundamental en el desarrollo del profesional moderno. Considerando lo anterior la Facultad de Ciencias Exactas Físicas y Naturales organiza el segundo seminario internacional en Ciencias Aplicadas,como una ventana a la integración de la investigación en la identificación de problemas cotidianos y a la búsqueda de soluciones a los mismos, contribuyendo a la vez el enriquecimiento profesional de los participantes y generando espacios de discusión científica en la Universidad de Santander UDES. OBJETIVOS Desarrollar temáticas de actualidad en diversas áreas del conocimiento con perspectivas de innovación y desarrollo tecnológico en áreas de la salud, investigación y el ambiente. Ofrecer talleres formativos para contextualizar el conocimiento de manera que los asistentes reconozcan las herramientas tecnológicas utilizadas para obtener mejores resultados en su futuro desempeño como profesionales.

  1. Combustion of boron containing compositions

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Y.; Pivkina, A. [Institute of Chemical Physics, Russian Academy of Science, Moscow (Russian Federation)

    1996-12-31

    Boron is one of the most energetic components for explosives, propellants and for heterogeneous condensed systems in common. The combustion process of mixtures of boron with different oxidizers was studied. The burning rate, concentration combustion limits, the agglomeration and dispersion processes during reaction wave propagation were analysed in the respect of the percolation theory. The linear dependence of the burning rate on the contact surface value was demonstrated. The percolative model for the experimental results explanation is proposed. (authors) 5 refs.

  2. Smoldering Combustion Experiments in Microgravity

    Science.gov (United States)

    Walther, David C.; Fernandez-Pello, A. Carlos; Urban, David L.

    1997-01-01

    The Microgravity Smoldering Combustion (MSC) experiment is part of a study of the smolder characteristics of porous combustible materials in a microgravity environment. Smoldering is a non-flaming form of combustion that takes place in the interior of porous materials and takes place in a number of processes ranging from smoldering of porous insulation materials to high temperature synthesis of metals. The objective of the study is to provide a better understanding of the controlling mechanisms of smolder, both in microgravity and normal-gravity. As with many forms of combustion, gravity affects the availability of oxidizer and transport of heat, and therefore the rate of combustion. Microgravity smolder experiments, in both a quiescent oxidizing environment, and in a forced oxidizing flow have been conducted aboard the NASA Space Shuttle (STS-69 and STS-77 missions) to determine the effect of the ambient oxygen concentration and oxidizer forced flow velocity on smolder combustion in microgravity. The experimental apparatus is contained within the NASA Get Away Special Canister (GAS-CAN) Payload. These two sets of experiments investigate the propagation of smolder along the polyurethane foam sample under both diffusion driven and forced flow driven smoldering. The results of the microgravity experiments are compared with identical ones carried out in normal gravity, and are used to verify present theories of smolder combustion. The results of this study will provide new insights into the smoldering combustion process. Thermocouple histories show that the microgravity smolder reaction temperatures (Ts) and propagation velocities (Us) lie between those of identical normal-gravity upward and downward tests. These observations indicate the effect of buoyancy on the transport of oxidizer to the reaction front.

  3. Formation of fine particles in co-combustion of coal and solid recovered fuel in a pulverized coal-fired power station

    DEFF Research Database (Denmark)

    Wu, Hao; Pedersen, Anne Juul; Glarborg, Peter

    2011-01-01

    Fine particles formed from combustion of a bituminous coal and co-combustion of coal with 7 th% (thermal percentage) solid recovered fuel (SRF) in a pulverized coal-fired power plant were sampled and characterized in this study. The particles from dedicated coal combustion and co-combustion both...... appear to be an important formation mechanism. The elemental composition of the particles from coal combustion showed that S and Ca were significantly enriched in ultrafine particles and P was also enriched considerably. However, compared with supermicron particles, the contents of Al, Si and K were...

  4. O Sistema Nacional de Combate ao Abuso e à Exploração Sexual Infantojuvenil e o Plano Nacional: um exemplo de política pública aplicada

    Directory of Open Access Journals (Sweden)

    Thaísa Veras

    Full Text Available Este artigo tem por objetivo principal tratar de uma política pública aplicada, qual seja, o Sistema Nacional de Combate ao Abuso e à Exploração Sexual Infantojuvenil. Para tanto, inicialmente, é apresentada uma breve definição dos termos, com o intuito de esclarecer a forma como foram interpretados e utilizados no texto. Além disso, é definido o significado de políticas públicas, para que se tenha maior clareza sobre como estas podem auxiliar no entendimento do tema. Por fim, são apresentados os impactos sociais do Sistema Nacional e feito um breve relato sobre o Plano Nacional.

  5. Una metodología para el desarrollo de habilidades de localización y valoración de la información en los estudiantes de la Universidad Peruana de Ciencias Aplicadas (UPC)

    OpenAIRE

    2010-01-01

    La presente investigación desarrolla una propuesta metodológica para la búsqueda y evaluación de la información procedente de Internet, que tanto estudiantes como profesores utilizan como insumo para la realización de investigaciones académicas en la Universidad Peruana de Ciencias Aplicadas. Se pretende establecer cuál es el patrón de conducta que muestran los estudiantes al enfrentarse a un problema de búsqueda de información dentro el ámbito académico. Este patrón se delineó gracias a la i...

  6. La investigación en biomecánica aplicada a la natación olímpica: Evolución histórica y situación actual

    OpenAIRE

    2013-01-01

    A lo largo de los años, los records mundiales en natación han mejorado de forma notable respecto a otros deportes. Esto se ha debido, tanto a la mejora de la condición física de los nadadores como a la evolución de las técnicas de nado. Gran “culpa” de esto se debe al avance científico en el que se ha visto inmerso este deporte. El presente trabajo tiene como objetivo presentar de una forma organizada y coherente la evolución histórica de la investigación en biomecánica aplicada a la natación...

  7. Investigación sobre el cotidiano del sujeto: oportunidades para una ciencia aplicada

    Directory of Open Access Journals (Sweden)

    Manuel Amezcua

    2012-01-01

    Full Text Available Desde un modelo de investigación emergente, la Investigación Aplicada a los Cuidados, se propone reflexionar sobre una de las áreas de indagación: la Investigación sobre el Cotidiano del Sujeto. El cotidiano del sujeto se conceptualiza como un espacio de interacción social donde las personas ejercen autonomía para tomar decisiones y ejecutar acciones para cuidar su salud. A través de diseños principalmente cualitativos, la Investigación sobre el Cotidiano del Sujeto aporta evidencias útiles y pertinentes para la práctica enfermera porque hablan del contexto y desde la perspectiva de los sujetos. Estas evidencias pueden encuadrarse en cuatro grandes dimensiones: la comprensión del padecimiento humano ante la enfermedad, la cultura del cuidado, la percepción sobre las intervenciones en salud, y el cotidiano del cuidador. Finalmente se plantean algunos desafíos que nos propone la Investigación sobre el Cotidiano del Sujeto e implican tres dimensiones imprescindibles en el ejercicio del cuidado: la dimensión ética, política y científica.

  8. Rotary internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Witkowski, J.

    1989-12-05

    This patent describes an internal combustion engine assembly. It includes: a central rotor means formed with at least one peripheral fuel cavity. The cavity having a first surface defining a thrust surface and a second surface defining a contoured surface; a housing means enclosing the rotor and having an internal wall encircling the rotor. The internal wall being intercepted by at least two recesses defining cylinder means. The housing means and the rotor means being relatively rotatable; piston means individual to each the cylinder means and reciprocable therein; each piton means having a working face complementary to aid contoured surface; and power means for urging the working face into intimate areal contact with the contoured surface to create a first seal means. The housing means having at lest one fuel inlet port, at least one fuel ignition means and at least one exhaust port whereby during the course of a revolution of the rotor means relative to the housing means, the first seal means, the power means, the respective ports, the ignition means and the fuel cavity cooperate to develop fuel compression, fuel ignition and exhaust functions.

  9. Internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Laskaris, M.A.; Broitman, K.; Natale, S.E.

    1991-08-27

    This patent describes improvement in a two-stroke internal combustion engine adapted to run on a diesel or a kerosene type of fuel, and including a piston connected to the crankshaft of the engine to move within a cylinder through a first stroke from a top dead center position to a bottom dead center position and through a second stroke from the bottom dead center position back to the top dead center position. The improvement comprises: means providing a cylinder head at the top end of the engine cylinder in the shape of an open bowl having a generally cup-shaped configuration including a sidewall portion, a spark plug positioned centrally within the bowl at the top end of the cylinder, and means for injecting fuel into the top end of the engine cylinder at a location between the spark plug and the sidewall portion, the fuel injecting means including an injection nozzle having a plurality of nozzle openings therein, the nozzle openings being constructed and arranged to discharge a plurality of plume-like sprays into the top end of the cylinder at a location within the bowl, two of the sprays being directed from the nozzle to diverge and pass along opposite sides of the spark plug, and additional sprays being directed from the nozzle against the sidewall portion or the cylinder head to be deflected therefrom back toward the piston and the spark plug to thereby form a cloud of fuel over the spark plug for good ignition.

  10. Combustion Mechanisms of Solids

    Science.gov (United States)

    1986-08-01

    investigated remained intact to temperatures as high as 700 OK. In 1977, Baer, Hedges, Seader , et al., in a singular paper E203, reported another fast...No. 3, 1966, pp. 1031 - 1037. 10. Baer, A. D., Hedges, J. H., Seader , J. D., Jayakar, K. M., Wojcik, L. H., "Polymer Pyrolysis over a Wide Range of

  11. La wiki-webquest: una actividad colaborativa en la asignatura de "Nuevas Tecnologías Aplicadas a la Educación"

    Directory of Open Access Journals (Sweden)

    Roberto Santos Fernández

    2010-01-01

    Full Text Available Las instituciones de educación superior están sufriendo un proceso de reconversión buscando su adaptación a las características del Espacio Europeo de Educación Superior. Uno de los cambios más importantes, a los que debe hacer frente su profesorado, consiste en una reorganización metodológica diferente de sus clases. Por ello, es necesario pensar en nuevas fórmulas en la formación del profesorado. Como resultado de esta necesidad, decidimos organizar la asignatura de Nuevas Tecnologías Aplicadas a la Educación, de la Facultad de Educación de Valladolid, empleando una metodología activa, el IBL, apoyada en una plataforma Wiki, proponiendo a nuestro alumnado una serie de actividades que debían realizar colaborativamente. En este trabajo, presentamos una de esas actividades, la elaboración de una Wiki- WebQuest. A partir de la descripción de esta actividad, pretendemos mostrar algunas luces y sombras sobre su puesta en práctica (la versatilidad y flexibilidad de la plataforma, la posibilidad de colaboración entre la universidad y la escuela, la falta de adaptación de algunos contenidos al nivel curricular del curso concreto, la falta de asesoramiento del profesorado al alumnado de primaria sobre el uso de estas nuevas herramientas, etc. Esta actividad fue desarrollada a partir de la colaboración con contextos educativos reales (dos centros de primaria, sirviendo de caso de estudio para diseñar una Wiki-WebQuest. Asimismo, también colaboraron dos asignaturas de la titulación de Magisterio (Didáctica General y Metodología del Idioma Extranjero, con el objetivo de enriquecer el proceso de aprendizaje.

  12. Generation of fast propagating combustion and shock waves with copper oxide/aluminum nanothermite composites

    Science.gov (United States)

    Apperson, S.; Shende, R. V.; Subramanian, S.; Tappmeyer, D.; Gangopadhyay, S.; Chen, Z.; Gangopadhyay, K.; Redner, P.; Nicholich, S.; Kapoor, D.

    2007-12-01

    Nanothermite composites containing metallic fuel and inorganic oxidizer are gaining importance due to their outstanding combustion characteristics. In this paper, the combustion behaviors of copper oxide/aluminum nanothermites are discussed. CuO nanorods were synthesized using the surfactant-templating method, then mixed or self-assembled with Al nanoparticles. This nanoscale mixing resulted in a large interfacial contact area between fuel and oxidizer. As a result, the reaction of the low density nanothermite composite leads to a fast propagating combustion, generating shock waves with Mach numbers up to 3.

  13. Aproximación funcional al efecto supresivo de la cáscara de almendra compostada aplicada al cultivo del aguacate

    OpenAIRE

    Vida, Carmen; de Vicente, Antonio; Cazorla, Francisco M

    2016-01-01

    La podredumbre blanca de la raíz, causada por el hongo fitopatógeno Rosellinia necatrix, es uno de los problemas más graves del cultivo del aguacate en el área mediterránea. Desde hace años, el manejo integrado de la enfermedad ha incluido la aplicación de enmiendas orgánicas como estrategia para mejorar el estado fitosanitario de los suelos agrícolas. En este trabajo, se llevaron a cabo ensayos “in vitro” frente a R. necatrix para evaluar la capacidad supresiva de los suelos enmendados con c...

  14. Twenty-second symposium (international) on combustion

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The following research areas were discussed at the symposium: coal combustion: carbon burnout, pyrolysis, furnaces, laboratory-scale combustion, and fluidized bed combustion; combustion-generated particulates: soot inception, growth, and soot formation in diffusion flames; engine combustion; turbulent combustion: flames in vortices, fractals and cellular automations, nonpremixed flames, premixed flames, premixed flame structure, and lifted flames; reaction kinetics: hydrocarbon oxidation, free radical chemistry, unsaturated species, aromatics, and nitrogen compounds/pollutant formation; combustion generated NO/sub x/ and SO/sub x/; fires: flame spread, radiation, characterization, and unsteady flames; Laminar flames: structure, opposed-flow combustion, shape, propagation/extinction, and inhibition, oscillations, microgravity; ignition; detonations; dusts; propellants; diagnostics; combustion of drops, sprays, and dispersions, and slurries. Individual projects are processed separately for the data bases. (CBS)

  15. Combustion iron distribution and deposition

    Science.gov (United States)

    Luo, Chao; Mahowald, N.; Bond, T.; Chuang, P. Y.; Artaxo, P.; Siefert, R.; Chen, Y.; Schauer, J.

    2008-03-01

    Iron is hypothesized to be an important micronutrient for ocean biota, thus modulating carbon dioxide uptake by the ocean biological pump. Studies have assumed that atmospheric deposition of iron to the open ocean is predominantly from mineral aerosols. For the first time we model the source, transport, and deposition of iron from combustion sources. Iron is produced in small quantities during fossil fuel burning, incinerator use, and biomass burning. The sources of combustion iron are concentrated in the industrialized regions and biomass burning regions, largely in the tropics. Model results suggest that combustion iron can represent up to 50% of the total iron deposited, but over open ocean regions it is usually less than 5% of the total iron, with the highest values (ocean biogeochemistry the bioavailability of the iron is important, and this is often estimated by the fraction which is soluble (Fe(II)). Previous studies have argued that atmospheric processing of the relatively insoluble Fe(III) occurs to make it more soluble (Fe(II)). Modeled estimates of soluble iron amounts based solely on atmospheric processing as simulated here cannot match the variability in daily averaged in situ concentration measurements in Korea, which is located close to both combustion and dust sources. The best match to the observations is that there are substantial direct emissions of soluble iron from combustion processes. If we assume observed soluble Fe/black carbon ratios in Korea are representative of the whole globe, we obtain the result that deposition of soluble iron from combustion contributes 20-100% of the soluble iron deposition over many ocean regions. This implies that more work should be done refining the emissions and deposition of combustion sources of soluble iron globally.

  16. Combustion Byproducts Recycling Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F

  17. Dimensionless Parameter Scaling of Diesel Engine Combustion

    Science.gov (United States)

    Dowling, David R.; Filipi, Zoran

    1996-11-01

    Combustion in a modern heavy-duty Diesel engine with direct radial fuel injection typically takes place in a short nearly-cylindrical volume at a rate determined by turbulent mixing. Simple dimensionless-parameter scaling laws for turbulent gas-phase mixing and heat transfer have been shown to be effective for a variety of (oxidizer) flow and (fuel) injection conditions within a cylindrical geometry (Edwards et al., AIChE J., Vol. 31, 516 [1985].) (Breidenthal et al., JFM, Vol. 219, 531 [1990].) (Dowling et al., AIAA J. Thermophys. & HT, Vol. 4, 504 [1990].). These studies were driven by chemical laser applications emphasizing long cylinders and sidewall injection. The current investigation seeks to determine the applicability of dimensionless parameter scaling to the instantaneous in-cylinder fuel burning rate in a multi-cylinder Diesel engine typical of Class VIII trucks. Comparisons are made between scaled and unscaled fuel burning rate, as inferred from time-resolved in-cylinder pressure measurements, across the test engine's normal operating range. This research is supported by the US Army Tank-Automotive Research, Development, and Engineering Center.

  18. Artificial intelligence applied to fuel management in BWR type reactors; Inteligencia artificial aplicada a la administracion de combustible en reactores BWR

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz S, J.J

    1998-10-01

    In this work two techniques of artificial intelligence, neural networks and genetic algorithms were applied to a practical problem of nuclear fuel management; the determination of the optimal fuel reload for a BWR type reactor. This is an important problem in the design of the operation cycle of the reactor. As a result of the application of these techniques, comparable or even better reloads proposals than those given by expert companies in the subject were obtained. Additionally, two other simpler problems in reactor physics were solved: the determination of the axial power profile and the prediction of the value of some variables of interest at the end of the operation cycle of the reactor. Neural networks and genetic algorithms have been applied to solve many problems of engineering because of their versatility but they have been rarely used in the area of fuel management. The results obtained in this thesis indicates the convenience of undertaking further work on this area and suggest the application of these techniques of artificial intelligence to the solution of other problems in nuclear reactor physics. (Author)

  19. Nutrição aplicada à atividade motora Nutrition applied to motor activity

    Directory of Open Access Journals (Sweden)

    Antonio Herbert Lancha Junior

    2011-12-01

    Full Text Available A Nutrição aplicada a atividade motora se divide em quatro áreas do movimento humano, a saber: esporte, educação física, dança, recreação/lazer. Essa definição conceitual diferencia a população alvo da intervenção nutricional. O organismo humano sempre apresentou o movimento como parte de sua atividade cotidiana e selecionou evolutivamente os organismos mais econômicos. Em contrapartida por conta de demandas, sociais, financeiras dentre outras a vida moderna impôs o sedentarismo como padrão de comportamento motor que aliado ao padrão genético de economia resultaram nas doenças modernas como obesidade, diabetes, etc. Assim a sociedade institucionalizou o movimento humano criando manifestações distintas descritas acima e suas necessidades específicas passaram a ser de interesse acadêmico/cientifico. Nutricionalmente os estudos se concentram no balanço energético, na necessidade de carboidratos, proteínas, lipídios assim como dos micronutrientes e outros compostos biologicamente ativos. Estes estudos definem estas substancias sob critérios de essencialidade ou efeito ergogênico superior a capacidade fisiológica. O primeiro determina mudanças nas necessidades nutricionais e o segundo substâncias consideradas ilícitas. No presente momento grande parte da comunidade cientifica dedicada à nutrição aplicada à atividade motora, dirige sua vocação na tentativa de descobrir as necessidades específicas provocadas pela pratica regular da atividade motora permitindo seu exercício regular para que a mesma propicie os benefícios na manutenção da saúde de forma plena nas quatro áreas descritas acima.Nutrition applied to motor activity is divided in four areas of human movement, namely: sports, physical education, dance, recreation/leisure. This conceptual definition differentiates the target population of nutritional intervention. The human body has always presented the movement as part of their daily activity and

  20. Subgrid Combustion Modeling for the Next Generation National Combustion Code

    Science.gov (United States)

    Menon, Suresh; Sankaran, Vaidyanathan; Stone, Christopher

    2003-01-01

    In the first year of this research, a subgrid turbulent mixing and combustion methodology developed earlier at Georgia Tech has been provided to researchers at NASA/GRC for incorporation into the next generation National Combustion Code (called NCCLES hereafter). A key feature of this approach is that scalar mixing and combustion processes are simulated within the LES grid using a stochastic 1D model. The subgrid simulation approach recovers locally molecular diffusion and reaction kinetics exactly without requiring closure and thus, provides an attractive feature to simulate complex, highly turbulent reacting flows of interest. Data acquisition algorithms and statistical analysis strategies and routines to analyze NCCLES results have also been provided to NASA/GRC. The overall goal of this research is to systematically develop and implement LES capability into the current NCC. For this purpose, issues regarding initialization and running LES are also addressed in the collaborative effort. In parallel to this technology transfer effort (that is continuously on going), research has also been underway at Georgia Tech to enhance the LES capability to tackle more complex flows. In particular, subgrid scalar mixing and combustion method has been evaluated in three distinctly different flow field in order to demonstrate its generality: (a) Flame-Turbulence Interactions using premixed combustion, (b) Spatially evolving supersonic mixing layers, and (c) Temporal single and two-phase mixing layers. The configurations chosen are such that they can be implemented in NCCLES and used to evaluate the ability of the new code. Future development and validation will be in spray combustion in gas turbine engine and supersonic scalar mixing.

  1. Explosion limits for combustible gases

    Institute of Scientific and Technical Information of China (English)

    TONG Min-ming; WU Guo-qing; HAO Ji-fei; DAI Xin-lian

    2009-01-01

    Combustible gases in coal mines are composed of methane, hydrogen, some multi-carbon alkane gases and other gases. Based on a numerical calculation, the explosion limits of combustible gases were studied, showing that these limits are related to the concentrations of different components in the mixture. With an increase of C4H10 and C6H14, the Lower ExplosionLimit (LEL) and Upper Explosion-Limit (UEL) of a combustible gas mixture will decrease clearly. For every 0.1% increase in C4H10 and C6H14, the LEL decreases by about 0.19% and the UEL by about 0.3%. The results also prove that, by increasing the amount of H2, the UEL of a combustible gas mixture will increase considerably. If the level of H2 increases by 0.1%, the UEL will increase by about 0.3%. However, H2 has only a small effect on the LEL of the combustible gas mixture. Our study provides a theoretical foundation for judging the explosion risk of an explosive gas mixture in mines.

  2. Transport Properties for Combustion Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J.; Bastein, L.; Price, P.N.

    2010-02-19

    This review examines current approximations and approaches that underlie the evaluation of transport properties for combustion modeling applications. Discussed in the review are: the intermolecular potential and its descriptive molecular parameters; various approaches to evaluating collision integrals; supporting data required for the evaluation of transport properties; commonly used computer programs for predicting transport properties; the quality of experimental measurements and their importance for validating or rejecting approximations to property estimation; the interpretation of corresponding states; combination rules that yield pair molecular potential parameters for unlike species from like species parameters; and mixture approximations. The insensitivity of transport properties to intermolecular forces is noted, especially the non-uniqueness of the supporting potential parameters. Viscosity experiments of pure substances and binary mixtures measured post 1970 are used to evaluate a number of approximations; the intermediate temperature range 1 < T* < 10, where T* is kT/{var_epsilon}, is emphasized since this is where rich data sets are available. When suitable potential parameters are used, errors in transport property predictions for pure substances and binary mixtures are less than 5 %, when they are calculated using the approaches of Kee et al.; Mason, Kestin, and Uribe; Paul and Warnatz; or Ern and Giovangigli. Recommendations stemming from the review include (1) revisiting the supporting data required by the various computational approaches, and updating the data sets with accurate potential parameters, dipole moments, and polarizabilities; (2) characterizing the range of parameter space over which the fit to experimental data is good, rather than the current practice of reporting only the parameter set that best fits the data; (3) looking for improved combining rules, since existing rules were found to under-predict the viscosity in most cases; (4

  3. New Combustion Regimes and Kinetic Studies of Plasma Assisted Combustion

    Science.gov (United States)

    2012-11-01

    Tasks 8 and 9: Kinetic model validation) Today’s Presentation 2. Multispecies diagnostics in a flow reactor with Mid-IR and molecular beam mass...S-Curve Competition between low T RO2 kinetics high T chain branching reactions 0.00 0.02 0.04 0.06 0.08 0.10 0.12 1x10 5 2x10 5 3x10 5 4x10...in Plasma assisted combustion • LTC in turbulent combustion at engine time scales 0-D modeling of DME /O2/He (0.03/0.1/0.896) ignition, P = 72

  4. A comprehensive fractal char combustion model☆

    Institute of Scientific and Technical Information of China (English)

    Yuting Liu; Rong He

    2016-01-01

    The char combustion mechanisms were analyzed and a comprehensive fractal char combustion model was developed to give a better understanding and better predictions of the char combustion characteristics. Most of the complex factors affecting the char combustion were included, such as the coupling effects between the pore diffusion and the chemical reactions, the evolution of the char pore structures and the variation of the apparent reaction order during combustion, the CO/CO2 ratio in the combustion products and the correction for oxy-char combustion. Eleven different chars were then combusted in two drop tube furnaces with the conversions of the partly burned char samples measured by thermogravimetric analysis. The combustion processes of these chars were simulated with the predicted char conversions matching very well with the measured data which shows that this char combustion model has good accuracy. The apparent reaction order of the char combustion decreases, stabilizes and then increases during the combustion process. The combustion rates in the oxy-mode are general y slower than in the air-mode and the effect of the char-CO2 gasification reac-tion becomes obvious only when the temperature is relatively high and the O2 concentration is relatively low.

  5. Extension of the ReaxFF Combustion Force Field toward Syngas Combustion and Initial Oxidation Kinetics.

    Science.gov (United States)

    Ashraf, Chowdhury; van Duin, Adri C T

    2017-02-09

    A detailed insight of key reactive events related to oxidation and pyrolysis of hydrocarbon fuels further enhances our understanding of combustion chemistry. Though comprehensive kinetic models are available for smaller hydrocarbons (typically C3 or lower), developing and validating reaction mechanisms for larger hydrocarbons is a daunting task, due to the complexity of their reaction networks. The ReaxFF method provides an attractive computational method to obtain reaction kinetics for complex fuel and fuel mixtures, providing an accuracy approaching ab-initio-based methods but with a significantly lower computational expense. The development of the first ReaxFF combustion force field by Chenoweth et al. (CHO-2008 parameter set) in 2008 has opened new avenues for researchers to investigate combustion chemistry from the atomistic level. In this article, we seek to address two issues with the CHO-2008 ReaxFF description. While the CHO-2008 description has achieved significant popularity for studying large hydrocarbon combustion, it fails to accurately describe the chemistry of small hydrocarbon oxidation, especially conversion of CO2 from CO, which is highly relevant to syngas combustion. Additionally, the CHO-2008 description was obtained faster than expected H abstraction by O2 from hydrocarbons, thus underestimating the oxidation initiation temperature. In this study, we seek to systemically improve the CHO-2008 description and validate it for these cases. Additionally, our aim was to retain the accuracy of the 2008 description for larger hydrocarbons and provide similar quality results. Thus, we expanded the ReaxFF CHO-2008 DFT-based training set by including reactions and transition state structures relevant to the syngas and oxidation initiation pathways and retrained the parameters. To validate the quality of our force field, we performed high-temperature NVT-MD simulations to study oxidation and pyrolysis of four different hydrocarbon fuels, namely, syngas

  6. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  7. Combustion synthesis method and products

    Science.gov (United States)

    Holt, J.B.; Kelly, M.

    1993-03-30

    Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.

  8. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

  9. Fundamentals of premixed turbulent combustion

    CERN Document Server

    Lipatnikov, Andrei

    2012-01-01

    Lean burning of premixed gases is considered to be a promising combustion technology for future clean and highly efficient gas turbine engines. This book highlights the phenomenology of premixed turbulent flames. The text provides experimental data on the general appearance of premixed turbulent flames, physical mechanisms that could affect flame behavior, and physical and numerical models aimed at predicting the key features of premixed turbulent combustion. The author aims to provide a simple introduction to the field for advanced graduate and postgraduate students. Topics covered include La

  10. Autodesk Combustion 4 fundamentals courseware

    CERN Document Server

    Autodesk,

    2005-01-01

    Whether this is your first experience with Combustion software or you're upgrading to take advantage of the many new features and tools, this guide will serve as your ultimate resource to this all-in-one professional compositing application. Much more than a point-and-click manual, this guide explains the principles behind the software, serving as an overview of the package and associated techniques. Written by certified Autodesk training specialists for motion graphic designers, animators, and visual effects artists, Combustion 4 Fundamentals Courseware provides expert advice for all skill le

  11. Free Energy and Internal Combustion Engine Cycles

    CERN Document Server

    Harris, William D

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  12. Scramjet Combustion Stability Behavior Modeling Project

    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...

  13. Scramjet Combustion Stability Behavior Modeling Project

    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...

  14. 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.

  15. 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 c

  16. 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 c

  17. Some polemical issues in Applied Linguistics Alguns temas polêmicos na disciplina de linguística aplicada

    Directory of Open Access Journals (Sweden)

    John Robert Schmitz

    2010-01-01

    Full Text Available In this paper, I look at three polemical issues in Applied Linguistics. I argue, first of all, that the desire for a stable definition of applied linguistics has by no means prevented research in the discipline. Secondly, I contend that the notion or "tradition" of "linguistics applied" (corpus linguistics or lexicography is broader and more serious than "applicationism" (the use of linguistic formalisms, artificial practices, and terminology in teaching material that are problematic and motivated by commercial interests. Thirdly, I argue that Educational Linguistics and Applied Linguistics have overlapping research objectives. In the course of the paper, I present some reservations about Educational Linguistics.Neste trabalho, examino três temas polêmicos na disciplina de Linguística Aplicada. Argumento, em primeiro lugar, que o desejo de uma definição estável de Linguística Aplicada, de nenhuma forma, tem impedido a pesquisa no âmbito da disciplina. Em segundo lugar, argumento que a "Linguistics Applied" (a linguística do corpus ou a lexicologia são muito mais abrangentes e sérias do que as práticas "aplicacionistas" (o uso de formalismo, artificialismos e nomenclatura em material didático que são problemáticos e motivados por interesses comerciais. Em terceiro lugar, argumento que a Linguística Educacional e a Linguística Aplicada têm objetivos de pesquisa que se sobrepõem. No decorrer do trabalho, apresento algumas reservas minhas sobre a Linguística Educacional.

  18. Combustion Chemistry Diagnostics for Cleaner Processes.

    Science.gov (United States)

    Kohse-Höinghaus, Katharina

    2016-09-12

    Climate change, environmental problems, urban pollution, and the dependence on fossil fuels demand cleaner, renewable energy strategies. However, they also ask for urgent advances in combustion science to reduce emissions. For alternative fuels and new combustion regimes, crucial information about the chemical reactions from fuel to exhaust remains lacking. Understanding such relations between combustion process, fuel, and emissions needs reliable experimental data from a wide range of conditions to provide a firm basis for predictive modeling of practical combustion processes.

  19. Simulation study on combustion of biomass

    Science.gov (United States)

    Zhao, M. L.; Liu, X.; Cheng, J. W.; Liu, Y.; Jin, Y. A.

    2017-01-01

    Biomass combustion is the most common energy conversion technology, offering the advantages of low cost, low risk and high efficiency. In this paper, the transformation and transfer of biomass in the process of combustion are discussed in detail. The process of furnace combustion and gas phase formation was analyzed by numerical simulation. The experimental results not only help to optimize boiler operation and realize the efficient combustion of biomass, but also provide theoretical basis for the improvement of burner technology.

  20. 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.

  1. O SIGNIFICADO DA ADMINISTRAÇÃO APLICADA À ENFERMAGEM SEGUNDO A OPINIÃO DE GRADUANDAS

    Directory of Open Access Journals (Sweden)

    Paulina Kurcgant

    Full Text Available Este estudo teve por objetivo conhecer as opiniões que as alunas têm, quando chegam para cursar a disciplina Administração aplicada à Enfermagem. Para tanto, coletou-se as opiniões de 30 alunas do 8° semestre do Curso de Graduação da EEUSP. Os resultados mostraram que as alunas consideram a administração como uma forma de organizar o trabalho e que a função administrativa da enfermeira consiste em conciliar a assistência com a burocracia do serviço.

  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. New technologies applied to food frequency questionnaires: a current perspective Nuevas tecnologías aplicadas a los cuestionarios de frecuencia de consumo de alimentos: una perspectiva actual

    Directory of Open Access Journals (Sweden)

    P. García-Segovia

    2011-08-01

    Full Text Available The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies applied to FFQ. It will be presented the purpose of the food frequency questionnaire, the number of strengths of the web-based surveys versus print-surveys and finally, a description of the manuscripts that have used web-based and computerized FFQ.Los cuestionarios de frecuencia de consumo de alimentos son muy utilizados en investigaciones epidemiológicas como método para evaluar la dieta. Tradicionalmente, han sido autoadministrados en papel, pero el uso de las tecnologías de la información y la comunicación (TICs ha permitido desarrollar cuestionarios de frecuencia de consumo de alimentos computerizados y a través de Internet. El objetivo de este artículo es ofrecer una perspectiva actual del uso de las nuevas tecnologías aplicadas al diseño e interpretación de los cuestionarios de frecuencia de consumo de alimentos. En el presente trabajo se resumen los objetivos de los cuestionarios de frecuencia de consumo de alimentos, las ventajas de los cuestionarios autoadministrados por Internet frente a los administrados en papel y finalmente, se describirán diferentes estudios que han usado cuestionarios de frecuencia de consumo de alimentos autoadministrados mediante el uso de ordenador o a través de Internet.

  4. Modelling and numerical simulation of two-phase flow processes and combustion processes in a ram-jet engine with boron as a solid fuel; Modellierung und numerische Simulation der zweiphasigen Stroemungs- und Verbrennungsvorgaenge in einem Staustrahltriebwerk mit Bor als Festtreibstoff

    Energy Technology Data Exchange (ETDEWEB)

    Hussmann, Bjoern

    2009-07-01

    The contribution under consideration contacts engineers and scientists within the range of numeric simulation of dense multiphase flows and in the area of the particle combustion. The first part of the contribution describes the flows arising in ram-jet engines with solid propellant such as particle-particle collisions and transsonic nozzle flows with a high load. The second part of the contribution is dedicated to the combustion processes at high-energy boron particles as fuel additive. The second part also gives a comprehensive review of the literature to this topic and compares the existing models. One of these models is extended by a more exact consideration of kinetics as well as diffusion processes at the particle and validated on the basis of experimental data from the literature. Finally, the author reports on the chemistry-turbulence coupling of particles combusting in turbulent flows.

  5. 30 CFR 56.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 56.4104 Section 56.4104... Control Prohibitions/precautions/housekeeping § 56.4104 Combustible waste. (a) Waste materials, including... properly, waste or rags containing flammable or combustible liquids that could create a fire hazard shall...

  6. 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...

  7. El sistema de inyección de combustible tipo bomba inyector UPS (Unit Pump System)

    OpenAIRE

    Tamayo Ramírez, Marlon Antonio; Hurtado Chiriboga, Hernán Mauricio

    2007-01-01

    El sistema de inyección de combustible electrónica diesel tipo bomba conducto inyector UPS (Unit Pump System), con bombas de inyección individual, es la continuación de los sistemas de inyección con bomba de inyección conjunta. Estas bombas llamadas bombas de inyección solidarias al bloque motor, se asignan individualmente a cada cilindro. En la bomba de inyección solidaria al bloque motor, la alta presión de combustible, se sigue produciendo según el principio de bomba de émbolo, como ...

  8. Sulfur Chemistry in Combustion II

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Kiil, Søren

    2000-01-01

    Several options are available to control the emission of SO2 from combustion processes. One possibility is to use a cleaner technology, i.e. fuel switching from oil and coal to natural gas or biomass, or to desulphurize coal and oil. Another possibility is to change to a different technology for ...

  9. Leaching from biomass combustion ash

    DEFF Research Database (Denmark)

    Maresca, Alberto; Astrup, Thomas Fruergaard

    2014-01-01

    The use of biomass combustion ashes for fertilizing and liming purposes has been widely addressed in scientific literature. Nevertheless, the content of potentially toxic compounds raises concerns for a possible contamination of the soil. During this study five ash samples generated at four...

  10. O conceito de lucro econômico no âmbito da contabilidade aplicada

    Directory of Open Access Journals (Sweden)

    Alessandra Hirano Fuji

    2004-12-01

    Full Text Available O estudo da Ciência Contábil e as definições de elementos financeiros, notadamente o lucro, são de grande relevância não somente para os estudiosos do meio acadêmico, mas também para aqueles que atuam no mercado financeiro e trabalham com as questões práticas da Contabilidade. O lucro contábil, que constitui basicamente o confronto entre receita realizada e custo consumido, é respaldado pelo conservadorismo, convenção da objetividade e Princípios Contábeis Geralmente Aceitos. O lucro econômico, que é o incremento do valor presente do patrimônio líquido, envolve aspectos subjetivos, mas é superior ao lucro contábil, mormente no processo decisório dos usuários internos e externos. A questão de pesquisa é se o conceito de lucro econômico encontra-se realmente difundido entre os profissionais da área contábil. O objetivo do trabalho é enfatizar a importância do conceito de lucro econômico e verificar qual o grau de assimilação, utilização e divulgação do conceito no âmbito da Contabilidade Aplicada. O trabalho, baseado em revisão da literatura e estudo exploratório mostra que o conceito de lucro econômico não é plenamente conhecido e utilizado pelos usuários da contabilidade.The study of accounting theory and the definitions of financial elements, especially profit, is highly relevant not only for academics, but also for those directly involved in practical activities related to applied accounting. Accounting profit is the confrontation between revenue and cost and is based on conservatism, objectivity and Generally Accepted Accounting Principles. Economic profit is the increase in the equity's present value and involves subjective aspects, but it is better than accounting profit, mainly in the context of internal and external users' decisionmaking process. The research question is whether the concept of economic profit is really widespread among accounting professionals. This study aims to emphasize the

  11. Inteligência artificial aplicada à Zootecnia Artificial intelligence in Animal Science

    Directory of Open Access Journals (Sweden)

    Ernane José Xavier Costa

    2009-07-01

    Full Text Available Os sistemas biológicos são surpreendentemente flexíveis pra processar informação proveniente do mundo real. Alguns organismos biológicos possuem uma unidade central de processamento denominada de cérebro. O cérebro humano consiste de 10(11 neurônios e realiza processamento inteligente de forma exata e subjetiva. A Inteligência Artificial (IA tenta trazer para o mundo da computação digital a heurística dos sistemas biológicos de várias maneiras, mas, ainda resta muito para que isso seja concretizado. No entanto, algumas técnicas como Redes neurais artificiais e lógica fuzzy tem mostrado efetivas para resolver problemas complexos usando a heurística dos sistemas biológicos. Recentemente o numero de aplicação dos métodos da IA em sistemas zootécnicos tem aumentado significativamente. O objetivo deste artigo é explicar os princípios básicos da resolução de problemas usando heurística e demonstrar como a IA pode ser aplicada para construir um sistema especialista para resolver problemas na área de zootecnia.Biological systems are surprising flexible in processing information in the real world. Some biological organisms have a central unit processing named brain. The human's brain, consisting of 10(11 neurons, realizes intelligent information processing based on exact and commonsense reasoning. Artificial intelligence (AI has been trying to implement biological intelligence in computers in various ways, but is still far from real one. Therefore, there are approaches like Symbolic AI, Artificial Neural Network and Fuzzy system that partially successful in implementing heuristic from biological intelligence. Many recent applications of these approaches show an increased interest in animal science research. The main goal of this article is to explain the principles of heuristic problem-solving approach and to demonstrate how they can be applied to building knowledge-based systems for animal science problem solving.

  12. Medidas de frecuencia, asociación e impacto en investigación aplicada

    Directory of Open Access Journals (Sweden)

    J.A. Mirón Canelo

    2008-06-01

    Full Text Available En la Sociedad actual del conocimiento y la información es preciso disponer de herramientas básicas para medir los fenómenos epidemiológicos como la enfermedad, la incapacidad o la siniestralidad laboral. Las formas de medir son instrumentos que se deben conocer y aplicar para planificar y tomar decisiones en Salud Pública y en Salud Laboral. El objetivo de este artículo es dar a conocer las principales medidas de frecuencia, asociación e impacto utilizadas en investigación aplicada, clínica o de Salud Pública para tratar de medir, valorar y estimar la importancia de los problemas de salud y enfermedades de relacionadas con el trabajo, de los factores de riesgo ocupacionales y otros eventos relacionados con la seguridad e higiene en el trabajo y, en definitiva, con la Salud de los trabajadores. Se describen los conceptos teóricos de las formas de medir en epidemiología, su interpretación y aplicación práctica de los indicadores básicos utilizados en la práctica habitual de los profesionales de las Ciencias de la Salud. Su utilidad fundamental es poder disponer de una información objetiva, fiable y precisa que permita tomar decisiones adecuadas y pertinentes en relación con la prevención, seguridad laboral, atención y rehabilitación de los trabajadores.In the society´current knowledge and information is necessary to have basic tools to measure the epidemic phenomena such as illness, disability or workplace accidents. The ways of measuring are instruments that they must know and apply to plan and take decisions on Public Health and Labour/Occupational Health. The aim of this article is to inform about the most important measures of frequency, association and impact used in applied research, clinical or Public Health to try to measure, to value and estimate the importance of health problems and diseases related work. The occupational risk factors and other events related to safety and healthy working conditions and ultimately

  13. Diferentes metodologias aplicadas ao ensino de astronomia no Ensino Médio

    Science.gov (United States)

    Albrecht, E.; Voelzke, M. R.

    2009-03-01

    O presente trabalho de intervenção foi realizado junto à Escola Estadual Colònia dos Pescadores na cidade de Caraguatatuba, com très turmas do terceiro ano do Ensino Médio, envolvendo 119 alunos com idades entre 16 e 19 anos. A fase inicial foi composta de um questionário de vinte questíes dissertativas e objetivas, aplicado pelo professor titular da sala, que era o mesmo nas très turmas, para diagnosticar nos educandos os conceitos prévios sobre Astronomia e, partindo destes realizar um trabalho de intervenção nas classes envolvidas utilizando, em cada uma, metodologias diferentes: (A) sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervençíes necessárias; (B) de forma tradicional, com auxílio de multimídias para desenvolvimento das aulas e a terceira (C) tradicional, fazendo uso exclusivo de lousa e giz. Ao final do trabalho os alunos responderam novamente o questionário inicial para diagnosticar dentre as très metodologias utilizadas qual apresentou melhores aplicaçíes, os resultados iniciais foram comparados com os finais. Quando questionados a respeito do significado de Astronomia observou-se inicialmente que os acertos na turma A foram de 100%, turma B: 64%, turma C: 84%, após a intervenção os acertos foram: 100%, 97% e 85% respectivamente, demonstrando que houve um avanço significativo na turma B, a turma A manteve seu índice e a turma C evoluiu, porém não tanto quanto a B. Quando interrogados sobre quantos planetas vocè acha que existem em nosso Sistema Solar? os acertos foram: turma A: 39%, turma B: 48% e turma C: 46%, após o desenvolvimento do trabalho os acertos foram 94%, 97% e 90% respectivamente. Dentro das respostas obtidas observa-se que a metodologia tradicional com o auxílio de multimeios, aplicada na turma B, demonstrou melhores resultados, sendo a mais significativa. Outra conclusão muito importante é que apesar de o tema Astronomia ser amplamente

  14. Comportamiento de la cirugía mayor aplicada a pacientes ambulatorios

    Directory of Open Access Journals (Sweden)

    Alexánder Rodríguez Rivero

    2001-03-01

    Full Text Available Se realizó una investigación observacional-descriptiva para conocer el comportamiento de la cirugía mayor aplicada a pacientes ambulatorios del Servicio de Cirugía General del Hospital General Provincial Docente «Capitán Roberto Rodríguez Fernández», de Morón, durante el período comprendido entre el 1ro. de enero de 1996 y el 30 de junio de 1998. La mayor proporción de casos de uno y otro sexos, pertenecía a los grupos de edad de 15 a 44 años. La hernia inguinal fue la afección más frecuente y por ende la intervención quirúrgica más realizada. El 10,5 % de los operados presentaba enfermedades asociadas. La anestesia espinal se utilizó en el 61,8 % de los intervenidos. El 2,2 % de los intervenidos tuvo complicaciones; sólo el 0,4 % de los pacientes necesitó hospitalización. El 100,0 % de los pacientes fue seguido por consulta especializada de cirugía y el médico de la familia. El método tuvo buena aceptación en el 99,6 % de los investigadosAn observational descriptive research was made in order to know the behavior of major surgery applied to outpatients from the Service of General Surgery of the "Capitán Roberto Rodriguez Fernández" General Teaching Hospital, in Morón, from January 1st, 1996, to June 30th, 1998. Most of the cases of both sexes were 15-44 years old. Inguinal hernia was the most frequent affection and, therefore, the most performed operation. 10.5% of the operated on individuals had associated diseases. Spinal anesthesia was used in 61.8% of those who underwent surgery. 2.2% had complications and just 0.4% needed hospitalization. 100% of the patients were followed up by the specialized surgery department and the family physician. The method had good acceptation in 99.6% of the investigated patients

  15. 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

  16. Fluidized-bed combustion of gasification residue

    Energy Technology Data Exchange (ETDEWEB)

    Kudjoi, A.; Heinolainen, A.; Hippinen, I.; Lu, Y. [Helsinki University of Technology, Espoo (Finland). Lab. of Energy Economics and Power Plant Engineering

    1998-12-31

    Hybrid combined cycle processes have been presented as possibilities for power generation in the future. In the processes based on partial gasification of coal, the solid materials removed from a gasifier (i.e. fly ash and bed char) contain unburned fuel, which is burned either in an atmospheric or a pressurised fluidised-bed. Pressurised fluidised-bed (PFB) combustion of gasification residues were studied experimentally by Helsinki University of Technology. The gasification residues, i.e. cyclone fines and bed chars, came from pilot scale PFB gasification tests of bituminous coals. The combustion efficiency was high in cyclone fines combustion. The calcium sulphide oxidised effectively to calcium sulphate in the combustion of cyclone fines. In bed char combustion the residual sulphide contents in solids after combustion were still relatively high. In general, sulphur dioxide emissions in residue combustion were low. The recarbonation of calcium oxide was observed in bed char combustion. Fuel-N conversion to NO{sub x} during bed char combustion and in most of the test runs with cyclone fines was higher than in bituminous coal combustion. In bed char combustion the conversion was significantly higher than in cyclone fines combustion. NO{sub x} emissions increased with increasing excess air for both residues, as was expected. In bed char combustion the highest NO{sub x} emissions were measured at higher pressure. Calculated mass reactivity values of equal particle size of all bed chars studied had similar trends with burnout. The biggest particles had the lowest reactivity values throughout the combustion, while reactivity for finer particles was at considerably higher level and sharply increases with burnout. In the constant combustion conditions used in the tests, no significant differences were observed in rate-controlling mechanisms for bed char fractions studied. 25 refs., 13 figs., 15 tab.

  17. Combustive management of oil spills

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris.

  18. The use of electrical discharge for ignition and control of combustion of solid propellants

    Science.gov (United States)

    Tachibana, Takeshi; Kobayashi, Tsuruo; Matsuda, Takashi; Kimura, Itsuro

    1987-01-01

    As the first step of the study of the combustion control of solid propellants by electrical discharges, the effects of an arc discharge, which flows along the burning surface, on the burning rate and on the increase of enthalpy of the combustion product were investigated. For specially devised composite propellants, which are composed of Al and Teflon powders, it was shown that the combination can be controlled by an arc discharge; the combustion continues when the arc discharge is applied and is interrupted when the arc discharge breaks. In the present investigation, it was also shown that an arc discharge coupled with a high-frequency electrical discharge has potential as an effective ignition method for solid propellants. For the application of this type of combustion control to an ignitor for a solid propellant rocket motor or to a control rocket motor, this method lacks flexibility in the configuration scale and needs relatively high electric power at the present stage.

  19. A two-phase restricted equilibrium model for combustion of metalized solid propellants

    Science.gov (United States)

    Sabnis, J. S.; Dejong, F. J.; Gibeling, H. J.

    1992-01-01

    An Eulerian-Lagrangian two-phase approach was adopted to model the multi-phase reacting internal flow in a solid rocket with a metalized propellant. An Eulerian description was used to analyze the motion of the continuous phase which includes the gas as well as the small (micron-sized) particulates, while a Lagrangian description is used for the analysis of the discrete phase which consists of the larger particulates in the motor chamber. The particulates consist of Al and Al2O3 such that the particulate composition is 100 percent Al at injection from the propellant surface with Al2O3 fraction increasing due to combustion along the particle trajectory. An empirical model is used to compute the combustion rate for agglomerates while the continuous phase chemistry is treated using chemical equilibrium. The computer code was used to simulate the reacting flow in a solid rocket motor with an AP/HTPB/Al propellant. The computed results show the existence of an extended combustion zone in the chamber rather than a thin reaction region. The presence of the extended combustion zone results in the chamber flow field and chemical being far from isothermal (as would be predicted by a surface combustion assumption). The temperature in the chamber increases from about 2600 K at the propellant surface to about 3350 K in the core. Similarly the chemical composition and the density of the propellant gas also show spatially non-uniform distribution in the chamber. The analysis developed under the present effort provides a more sophisticated tool for solid rocket internal flow predictions than is presently available, and can be useful in studying apparent anomalies and improving the simple correlations currently in use. The code can be used in the analysis of combustion efficiency, thermal load in the internal insulation, plume radiation, etc.

  20. Commercial Demonstration of Oxy-Coal Combustion Clean Power Technology

    Energy Technology Data Exchange (ETDEWEB)

    K.J. McCauley; K.C. Alexander; D.K. McDonald; N. Perrin; J.-P. Tranier [Babcock & Wilcox Power Generation Group (United Kingdom)

    2009-07-01

    Oxy-Coal Combustion is an advanced clean coal-based power generation technology with carbon capture and storage that will be Near Zero Emissions (NZEP), will capture and safely store CO{sub 2} in a geologic formation, and generate clean power for sale. This sustainable technology will utilize natural resources and support energy security goals. The unique benefits of oxy-coal combustion allow for near zero emissions of coal combustion products. The emissions of particulate matter, sulfur dioxide, nitrogen oxides and mercury will not only be below regulated levels, but all will be within the uncertainty of current industry measurement methods, essentially zero. This advanced technology will demonstrate all these reduced levels and will lead to commercially available NZEP plants for power generation. Since 1991, with the support of the US-DOE, Babcock & Wilcox Power Generation Group, Inc. (B&W PGG) and Air Liquide (AL) have worked to bring an advanced technology to the market for Carbon Capture and Storage (CCS) for coal-fired electric power generation plants. Oxy-coal combustion is now ready for at-scale demonstration leading directly to full scale commercialization and availability in the power generation marketplace. This paper will discuss the follow up of the results of the 30 MWth large pilot test program completed in December, 2008. This oxy-coal combustion technology has been through small lab pilot testing, large pilot testing, and a rigorous bottom-up integration and optimization analysis. Our paper will describe incorporating the best technological thinking for the integration of a modern PC-fired boiler, environmental control equipment, air separation unit (ASU) and compression purification unit (CPU). 5 refs., 3 figs.