WorldWideScience

Sample records for aportando piezas al

  1. Plaguicidas en la dieta: aportando piezas al rompecabezas Pesticides in the diet: adding pieces to the puzzle

    Directory of Open Access Journals (Sweden)

    Ángel Vicente

    2004-12-01

    Full Text Available Objetivos: Mejorar la información sobre la exposición a plaguicidas mediante la dieta en nuestro país con la presentación de los resultados de detección de 88 parámetros de plaguicidas en 1.109 muestras de alimentos, obtenidas entre 1998 y 2003 para el programa de Investigación de la Calidad Sanitaria de los Alimentos (ICSA de Barcelona. Material y método: Se presentan los resultados por grupos de alimentos y se comparan con la situación en el período anterior para frutas y hortalizas. La significación de las diferencias observadas se estima mediante la prueba de la χ². Resultados: En las 1.109 muestras analizadas se obtuvieron 116 resultados positivos para plaguicidas (10,5%. En el 1,5% de las muestras se detectaron halogenados persistentes y en el 14,4%, otros plaguicidas. Los positivos se concentran en frutas, hortalizas, especias y cereales y sus derivados. No hay positivos entre los aceites vegetales, los huevos ni los productos de la pesca, y casi no hay en los lácticos ni en los cárnicos. Las frutas concentran la mayor presencia de plaguicidas, en todos los casos no persistentes. Las hortalizas tienen menos plaguicidas, pero en ellas se detecta algún tipo de organoclorado. Al comparar los valores en las frutas y verduras con los de 1989-1997 no se aprecian diferencias que alcancen la significación estadística. Conclusiones: Aunque el volumen de muestras con plaguicidas es relevante, en su mayoría no son por productos halogenados persistentes. Destaca la elevada presencia de plaguicidas en la fruta.Objectives: To improve information on exposure to pesticides through diet in Spain by reporting the results on 88 pesticide parameters in 1,109 food samples obtained between 1998 and 2003 as part of the Barcelona program for research on the health quality of foods. Material and method: The results are presented by food groups. For fruits and vegetables, the results were compared with those for the previous period. Statistical

  2. Efectos térmicos en mecanizado de piezas de acero al carbono

    OpenAIRE

    Morán González, José Luis

    2011-01-01

    En esta Tesis se trata de predecir el calentamiento de una pieza durante su mecanizado, para ello se han utilizado dos modelos matemáticos diferentes para simular las temperaturas que se alcanzan en las distintas partes de una pieza debidas a un proceso de mecanizado por arranque de viruta. De los dos modelos utilizados uno ha sido un programa comercial que utiliza un algoritmo basado en elementos finitos y el otros es un programa de desarrollo propio basado en volumenes finitos. Este segu...

  3. La Evolución de la Lanza en Occidente (Piezas de Hierro de Hallstatt al Siglo XV

    Directory of Open Access Journals (Sweden)

    Cirlot, Juan Eduardo

    1967-12-01

    Full Text Available See Abstract in Spanish.

    DETERMINAR la evolución de la lanza es difícil, incluso en el área occidental. Fijar el período a que corresponde una determinada pieza con frecuencia implica los más graves problemas, y la posibilidad de error siempre está al acecho. Naturalmente, seriar cronológicamente lanzas de fecha determinada por hallazgos arqueológicos precisos: excavaciones de ruinas, tumbas, etc., es fácil. Pero aplicar los resultados que se obtienen con esta organización supuesta ya no lo es tanto. Ello se debe esencialmente a un hecho: la falta de caracterización estilística suficiente en gran número de piezas, aunque es innegable que hay otras cuya forma «dice» con claridad a qué mundo cultural pertenecen. Complementa esa falta de caracterización la riqueza tipológica que suele darse en cada período. El canon varía con libertad e igualmente las dimensiones e incluso la técnica. Para el coleccionista de lanzas, o para el investigador que se enfrenta con piezas que no proceden de hallazgos fechados, es muy arduo, pues, saber con aproximación a qué época y lugar corresponden tales armas. Tiene a su disposición varios elementos de juicio: la comparación con las armas procedentes de hallazgos fechados, la «calidad» (textura de la pieza, es decir, su aspecto táctil, que acaba por ser inconfundible o poco menos para el que frecuenta los objetos antiguos. Finalmente, por escasa que sea la «caracterización estilística», siempre hay alguna, y ayuda a corroborar o a rectificar las hipótesis formuladas con la base de los dos principios primeros.

  4. Equipo de fusión al vacío para la determinación cuantitativa del gas atrapado en piezas fundidas

    Directory of Open Access Journals (Sweden)

    Hernández-Ortega, J. J.

    2009-02-01

    Full Text Available Parts manufactured with casting processes may trap substantial quantities of gas, which could harm the mechanical properties of the manufactured parts. In this work, a vacuum melting device manufactured to measure trapped gas in castings is described. Adjustment correlations, which accurately calculate trapped gas quantity as a function of the pressure increments measured by the vacuum equipment, are obtained. Finally, as an application of the equipment, we present the results obtained for several parts manufactured using a pressure die casting machine. It is expected that the vacuum melting device will be useful to optimize the operating conditions which reduce the trapped gas in casting processes.

    Las piezas obtenidas mediante procesos de fundición pueden contener cantidades importantes de gas ocluido, lo que podría afectar negativamente a las propiedades mecánicas de las piezas fabricadas. En este artículo se describe un equipo de fusión al vacío fabricado para la determinación de la cantidad de gas ocluido en piezas obtenidas mediante procesos de fundición. Se han obtenido correlaciones de ajuste que permiten el cálculo, con un buen grado de precisión, de la cantidad de gas ocluido en piezas fundidas en función de los incrementos de presión detectados por el equipo de vacío. Finalmente, se presentan, como aplicación del equipo, los resultados obtenidos en piezas fabricadas en una máquina industrial de fundición por inyección a presión. Se espera que el equipo desarrollado sea de gran utilidad para optimizar las condiciones de operación que reduzcan el aire atrapado en procesos de fundición.

  5. Propiedades mecánicas bajo compresión y resistencia al desgaste abrasivo de piezas gruesas de caucho acrilonitrilo

    Directory of Open Access Journals (Sweden)

    Sandra Milena Velásquez-Restrepo

    2015-09-01

    Full Text Available Se estudió la variación de las propiedades mecánicas bajo compresión uniaxial y el desgaste abrasivo en la sección transversal de piezas gruesas de caucho acrilonitrilo (NBR reforzadas con negro de humo, teniendo en consideración que en este tipo de piezas las propiedades obtenidas durante la vulcanización no son homogéneas, debido a la baja difusividad térmica de los cauchos. Se realizaron ensayos de desgaste abrasivo en seco, buscando identificar la relación entre la resistencia al desgaste abrasivo y las propiedades mecánicas en compresión, como el módulo elástico y la dureza. Se evaluaron muestras en estado de entrega tras el proceso de vulcanización, luego expuestas al ambiente durante tres meses y, posteriormente, envejecidas en una cámara UV. El envejecimiento ambiental rigidiza los materiales estudiados, pero disminuye la resistencia al desgaste del material proveniente del núcleo de las piezas. El envejecimiento UV disminuyó el módulo elástico, pero su efecto sobre la resistencia al desgaste depende del estado de envejecimiento previo. La dureza no presentó una relación directa ni con el módulo elástico ni con la resistencia al desgaste, por lo cual no puede usarse como propiedad para la selección de cauchos NBR sometidos a desgaste abrasivo. La información obtenida permite generar criterios para el diseño de componentes basados en este tipo de cauchos.

  6. Romeo y Julieta : diez piezas para piano Op. 75 un acercamiento al color armónico e instrumental en Prokofiev

    OpenAIRE

    Sánchez Uribe, David

    2010-01-01

    Romeo y Julieta: Diez piezas para piano Op.75 es una suite compuesta por Prokofiev con extractos de su ballet Op.64 (1935), del que además realizó dos suites para orquesta. El régimen estalinista, que se extendió también a las artes, tuvo influencia en el lenguaje neoclásico en el que está escrita la obra, caracterizado por una búsqueda de claridad melódica y tonal, que fuese accesible al público en general. Durante el texto se harán consideraciones estéticas que relacionen el argumento con e...

  7. Buenas Piezas. Fernado Medina

    OpenAIRE

    Magazine, EME

    2011-01-01

    Conferencia Diseñando por ideas Facultad de Bellas Artes de San Carlos de Valencia Perfil del diseñador gráfico Fernando Medina Magazine, E. (2011). Buenas Piezas. Fernado Medina. EME Experimental Illustration, Art & Design. (1):8-11. doi:10.4995/eme.2011.1472. 8 11 1

  8. Piezas de la Historia

    Directory of Open Access Journals (Sweden)

    Cesar A. Pantoja

    1991-12-01

    Full Text Available

    En el presente número de ”Medicina” sale a la luz pública para su divulgación entre el cuerpo médico, la segunda parte de las apuntaciones críticas preparadas por el Presidente Otero-Ruiz, hechas con base en las notas cuidadosamente recogidas por el historiador Humberto Cáceres, a quien se le reconocen su gran interés y competencia en esta importante clase de estudios.

    Cronología histórica es el título del escrito de Otero.

    En el mismo orden se menciona el Prontuario elaborado bajo la dirección del expresidente académico Pablo Gómez Martínez, que contiene la lista y las referencias de los funcionarios y expresidentes de esta Corporación, con una relación completa que parte desde la fundación de la antigua Sociedad de Medicina y Ciencias Naturales en 1873.

    De esa fecha hasta hoy han pasado 118 años, lapso que cubre la mayor parte de la vida de la República, digno de recordación en vista de que corresponde a la evolución política y de la medicina colombiana.

    La Academia por esta circunstancia muy notable, conserva en sus anales y guarda en sus archivos un vasto acervo de conocimientos, de hechos magníficos que han sido cumplidos en el discreto recinto, pero que ahora cabe proyectar en el ámbito intelectual de la salud, por toda la Nación.

    Los volúmenes citados constituyen las piezas de la Historia, que se valoran con las memorias de las egregias figuras del pensamiento médico que por aquí han desfilado para honra y paz de la intelectualidad médica nacional.

    Los insignes antecesores del trabajo, dejaron un mensaje que este Cuerpo Colegial se esfuerza por no dejar que se extinga, preservando el patrimonio de ciencia y arte de la medicina propuestos a la buena atención de los habitantes del territorio, amparados así mismo, por el cumplimiento sin esguinces de la ética que enaltece a las profesiones de la salud.

    El lapso clásico a que concretamente se refieren estas l

  9. De la apología al triste cantar: la evaluación de la Conquista de México en las piezas teatrales de John Dryden (1667 y Fernando de Zárate (1668

    Directory of Open Access Journals (Sweden)

    Ana Núñez-Ronchi

    2012-07-01

    Full Text Available ResumenLa (representación de la conquista de América ha sido objeto creciente deestudio en los distintos ámbitos lingüísticos nacionales. Sin embargo, son pocos los estudios que se han interesado por la escenificación teatral de la Conquista desde una perspectiva comparativa. Recurriendo al aparato teórico-metodológico de la semántica interpretativa, este trabajo se propone comparar la visión inglesa y la española de la conquista de México en dos piezas de teatro europeas contemporáneas y presumiblemente basadas en las mismas fuentes históricas, "The Indian Emperour" de John Dryden (1667 y "La Conquista de México" de Fernando de Zárate (1668. Nuestra interpretación mostrará cómo, a pesar de sus similitudes, estas piezas presentan soluciones y evaluaciones divergentes respecto de los acontecimientos que escenifican.Palabras clave: comedia española - drama heroico - semántica interpretativa- conquista de MéxicoAbstractCriticism has been paying increased attention to the (representation of the Conquest of America in several national domains. Nevertheless, few studies encompass the theatrical depiction of the Conquest of Mexico from a comparative perspective. In accordance with textual semantics, this studyproposes to compare the Spanish and the English vision of the Conquest of Mexico in two contemporary and presumably historically-based works, John Dryden’s "The Indian Emperour" (1667 and Fernando de Zárate’s "La Conquista de México" (1668. Our interpretation will show that, despite their similarities, each work presents differing evaluations of the Conquestof Mexico.Keywords: Spanish Comedia - heroic drama - interpretative semantics - Conquest of Mexico

  10. Empleo de la cáscara de arroz en la fundición de piezas de acero al carbono//Using of rice husk in the carbon steel casting parts process

    Directory of Open Access Journals (Sweden)

    Juan Carlos Cruz-Pérez

    2012-05-01

    Full Text Available Los materiales auxiliares desempeñan un papel importante en el aumento de la eficiencia tecnológica del proceso de fundición de piezas de acero al carbono. En este artículo se exponen los primeros resultados del empleo de la cáscara de arroz como material termoaislante en la obtención de piezas fundidas de acero al carbono. En los experimentos se evaluó la influencia  de seis combinaciones de las variables espesor de pared del casquillo y capa de cobertura. En la confección de los casquillos se utilizó cáscara de arroz triturada, la que posteriormente fue aglutinada con silicato de sodio, apisonada y endurecida con CO2, mientras que la cobertura se utilizó sin procesamiento previo. El mayor nivel de entrega de acero se obtuvo al emplear un espesor de casquillo de 65 mm y una altura de cobertura de 85 mm. El valor del ASAF generado por las variantes experimentales resultó igual o inferior a 0,48. Palabras claves: casquillo termoaislante, polvo de cobertura, cáscara de arroz, acero fundido.______________________________________________________________________________ Abstract Feeding auxiliary materials perform a very important role in improves technological efficiency of carbon steel casting parts process. In this article are exposing the first results in the rice husk using as an insulating material in such process. The variables sleeve thickness and covering thickness’ influence were evaluated in six combinations by means of experiments. In sleeves preparation was used crushed rice husk, which was agglutinated with sodium silicate, compacted and hardened with CO2, meanwhile as covering it was uses without previous preparation. The mayor liquid steel delivering level was get employing 65 mm sleeve thickness and 85 mm covering thickness. The ASAF value generated for experimental variants was equal or inferior to 0.48. Key words: insulating sleeve, riser sleeve, hot topping, rice husk, steel cast.

  11. Conservación y elaboración de piezas anatómicas con sustancias diferentes al formol en la Facultad de Ciencias Agropecuarias de la Universidad de La Salle

    Directory of Open Access Journals (Sweden)

    César Alfonso Muñetón Gómez

    2011-12-01

    Full Text Available El presente estudio, realizado en el área de Anatomía, se basó en la búsqueda de una alternativa diferente al formol para la conservación de piezas anatómicas, teniendo en cuenta sustancias menos agresivas con el medioambiente, y buscando una disminución en el número de animales destinados para el estudio anatómico. Por otra parte, se realizó el diseño y la elaboración de modelos anatómicos en diferentes materiales como yeso, acrílico, látex y resinas para su utilización como herramienta didáctica en el proceso enseñanza-aprendizaje de la asignatura; así mismo, se dio inicio a la plastinación de algunos órganos a fin de permitir su conservación y estudio de la forma más natural posible.

  12. Buenas piezas. Cuando se siente

    OpenAIRE

    Martínez, Borja; Lo Siento; Molinero Domingo, Silvia

    2016-01-01

    Entrevista a Borja Martínez de Lo Siento Studio. Viajamos a Barcelona para conocer el espacio en el que Lo Siento desarrolla su trabajo. Se trata de un estudio reconocido por los proyectos de identidad gráfica, packaging, diseño editorial y especialmente valorados por la creación de atractivas tipografías. Han recibido varios Laus y Grand Laus, premios organizados por la Asociación de Diseñadores Gráficos y Directores de Arte (ADG-FAD), por ejemplo al álbum The Mill...

  13. Comportamiento del acabado superficial de la pieza y el desgaste de la herramienta al fresar aluminio con altas velocidades de corte en fresadoras cnc convencionales. // Superficial finish behavior and tool wear in aluminium milling with high cutting spee

    Directory of Open Access Journals (Sweden)

    F. Martínez Aneiro

    2006-05-01

    Full Text Available La demanda de componentes mecánicos de alta calidad y gran exactitud para sistemas de elevado desempeño estaaumentando considerablemente en los últimos años a nivel mundial. Este hecho ha provocado el desarrollo de nuevastecnologías aplicadas a los procesos de corte.El desarrollo integral de las máquinas herramientas (controles, husillos de alta velocidad de las herramientas de corte(nuevos materiales para los substratos y capas y de la tecnología de maquinado posibilitó la aplicación del corte con altasvelocidades de corte (High speed Cutting HSC. El aumento de las velocidades de corte es una de las formas de aumentar laeficiencia de los procesos productivos a través de la reducción de los tiempos de fabricación. La reducción en varias vecesde los tiempos de fabricación, se logra no solo por los tiempos de maquinado sino también por la sustitución o minimizarotros procesos de elaboración que forman parte de la cadena productiva, los cuales en ocasiones son relativamente lentoscomo son la electroerosión, el acabado manual en la producción de moldes y troqueles así como los cambios deoperaciones de la pieza.Por ser un proceso relativamente nuevo, introduciéndose a partir de la década de los años 90 aun existen muchas cuestionestecnológicas que están sin respuesta. Es interés del presente trabajo, mostrar los efectos de las altas velocidades de cortesobre la vida útil de la herramienta y el acabado superficial en la pieza, trabajando en máquinas fresadoras de CNC¨convencionales¨. Los resultados muestran que dentro de los parámetros estudiados la durabilidad de la herramienta y elacabado superficial mejoran y que el comportamiento de la máquina es estable a pesar de no estar concebida para el nuevoconcepto de altas velocidades.Palabras Claves: Altas velocidades de corte, HSC, HSM desgaste, acabado superficial.______________________________________________________________________________Abstract.The demand of

  14. Fabricación de piezas de fundición con grafito esferoidal en molde metálico

    Directory of Open Access Journals (Sweden)

    Urrestarazu, A.

    2013-10-01

    Full Text Available The features and suitability of high requirements ductile iron castings production using metallic moulds have been studied in the present work. The structural and mechanical properties of the produced castings have been analysed and compared to the corresponding ones but fabricated using green sand moulds according to a conventional production process. The higher cooling rate in the metallic moulds is the main cause for the appearance of the detected structural changes in castings. The mechanical and microstructural properties obtained directly on castings are remarkable due to the higher nodule count among other factors. Finally, the benefits and inconveniences found in this kind of production methodology using metallic moulds are also discussed.En este trabajo se estudia el empleo de moldes metálicos o permanentes para la fabricación de piezas de fundición esferoidal con elevados requerimientos funcionales y se analizan sus propiedades, comparándolas con piezas obtenidas utilizando moldes de arena de sílice, de acuerdo con las metodologías más habituales para este tipo de procesos. La elevada velocidad de solidificación y el posterior enfriamiento rápido de la austenita formada en estado sólido se erigen como los principales factores diferenciadores que originan las modificaciones estructurales detectadas en las piezas. Las propiedades físicas, mecánicas y microestructurales obtenidas directamente sobre pieza son destacables debido, entre otros aspectos, al gran número de esferoides grafíticos obtenidos en las piezas. Se discuten también las ventajas e inconvenientes encontrados en esta metodología de producción que emplea moldes fabricados con una aleación metálica específica.

  15. Razones para la extracción de piezas dentales en la Facultad de Odontología, Universidad de Costa Rica

    OpenAIRE

    Gómez-Delgado, Andrés; Montero-Aguilar, Mauricio

    2012-01-01

    La caries dental y la enfermedad periodontal han sido descritas como los principales factores etiológicos para la pérdida de piezas dentales a nivel mundial. Este es el primer estudio epidemiológico que evalúa las razones para extracción dental en Costa Rica. Objetivos: determinar las principales razones y reportar los patrones de extracción de piezas dentales en la población bajo estudio. Materiales y métodos: se incluyó a todos los pacientes que asistieron al servicio de exodoncia que prest...

  16. EL MUSEO KOLUMBA: ELOGIO DE LA PIEZA AUSENTE

    Directory of Open Access Journals (Sweden)

    Virginia Navarro Martínez

    2010-05-01

    Full Text Available RESUMEN El presente artículo trata de profundizar, a través del estudio del museo Kolumba, en algunos condicionantes específicos que posee el proyecto que debe trabajar con arquitecturas del pasado, destacando entre ellos el modo en el que el objeto de partida queda incluido y contenido en el resultado final. La realidad última que el edificio construye, mediante la interpretación de lo preexistente, es el espacio invisible de la memoria (la pieza ausente. Las intervenciones llevadas a cabo a raíz de la destrucción de la iglesia de Santa Columba en la Segunda Guerra Mundial hasta la inauguración del presente museo nos permiten entender el proyecto de Zumthor como la culminación de una trayectoria iniciada años atrás por Rudolf Schwarz con la reconstrucción de Colonia. La sensibilidad y la convergencia interpretativa de los sucesivos autores que en este espacio intervienen originan una lectura conjunta que trasciende la personalidad individual de cada uno de ellos. Se tratará también en este artículo de la obra de tres artistas, presentes en el museo, especialmente vinculados a la memoria del sitio y de la destrucción desde ópticas y modos creativos diferentes: Ulrich Tillman, Bill Fontana y Richard Serra.SUMMARY Through the study of the Kolumba Museum, the article attempts an in–depth study of some specific determinants that the plan must have in order to work with architectures from the past, emphasising the way in which the initial objective is encompassed in the final result. Through the interpretation of the pre–existing, the final reality that the building constructs is the invisible space of the memory (the missing piece. The interventions carried out as a result of the destruction of the church of Santa Columba in World War II until the inauguration of the present museum, allow us to understand Zumthor’s plan as the culmination of a process begun years ago by Rudolf Schwarz with the reconstruction of Cologne. The

  17. Distribución y corte de piezas irregulares con anidamiento bidimensional en la industria minera

    Directory of Open Access Journals (Sweden)

    José Arzola-Ruíz

    2010-03-01

    Full Text Available La necesidad del ahorro de material durante el corte de piezas en chapas ha provocado el desarrollo de procedimientos y técnicas de optimización, con la ayuda de las nuevas tecnologías de la informática y las comunicaciones. A pesar de la existencia de diversas plataformas automatizadas para la generación de distribuciones y rutas de corte, el ahorro de material constituye un indicador de permanente atención en la industria minera. En el presente trabajo se ilustra el estado actual del desarrollo de las técnicas de distribución y corte de piezas en chapas y se define la concepción de un procedimiento para la distribución de piezas irregulares con anidamiento bidimensional.

  18. Recondicionamiento de piezas de hierro fundido por tratamiento térmico (II Parte

    Directory of Open Access Journals (Sweden)

    Francisco Luis Hernández Arias

    2008-01-01

    Full Text Available Se aborda la importancia que posee el incremento de volumen del material, en piezas de hierro gris, a causa de los cambios estructurales que en las mismas provoca el tratamiento térmico; planteándose como objetivo fundamental el de mostrar que el tratamiento térmico no solamente es aplicado a piezas en el proceso de fabricación, sino que es posible su aplicación en el proceso de recuperación de piezas; escogiéndose como problema, el desgaste que sufren algunos elementos del motor de combustión interna (MCI, como son los segmentos y los sombreretes o tapetas del tractor KOMATSU, debido a la fricción que sufren estos elementos. Se muestra además la tecnología de recuperación tratamiento térmico empleada.

  19. Diseño y desarrollo de un contenedor de estructura metálica específico para piezas de automoción

    OpenAIRE

    2007-01-01

    El proyecto realizado, presenta los aspectos más importantes en el diseño completo de contenedores específicos, y las soluciones concretas aplicadas al diseño de un contenedor de estructura metálica para piezas de estampación del sector de automoción. El proyecto ofrece una guía a seguir en el diseño ergonómico de contenedores específicos, y concluye con un resumen de los aspectos más importantes que se han considerado a lo largo del mismo y, que pueden aplicarse en otros...

  20. Claves metalúrgicas de la fabricación de espadas con acero de Damasco (Al-hindi) según el taller persa medieval del shamshirsaz Assad Allâh de Isfahân

    OpenAIRE

    García Sánchez, Laura

    2011-01-01

    Nuestra investigación se enmarca dentro del campo de la Arqueometría y, más concretamente, de la Arqueometalurgia o metalurgia antigua (Paleometalurgia). Esta disciplina, a caballo entre la historia y la ciencia, se ocupa del estudio de todo tipo de piezas arqueológicas de naturaleza metálica, desde sus características macroscópicas a sus estructuras microscópicas, aportando información tanto de los procesos de minería como de los de extracción del metal, moldeo y conformación plástica; sin o...

  1. PIEZA DE NICOLÁS GODOY VEGA. HOYA PINEDA [Material gráfico

    OpenAIRE

    1990-01-01

    NICOLÁS GODOY VEGA SIEMPRE DESTACÓ POR SUS GANAS DE INNOVAR EN CUANDO A LAS FORMAS Y DECORACIÓN. SU CURIOSIDAD LE LLEVÓ A REALIZAR PIEZAS DE GRAN BELLEZA. Copia digital. Madrid: Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2015

  2. Diseño de troqueles para la fabricación de la pieza soporte pulsador

    OpenAIRE

    Barbarin Matute, Iñaki

    2014-01-01

    El objetivo de este proyecto fin de carrera es el diseño y fabricación de la pieza “soporte pulsador”, requerida por el cliente a la empresa “METRANSA” (Mecanizados y Troquelados Ainzoain SA). El desarrollo del proyecto trata, mediante el diseño y fabricación de un troquel para el doblado de dicha pieza, obtener la pieza en su contorno y posteriormente el troquelado de los agujeros. Por tanto, el proyecto tiene por objeto el desarrollo de las especificaciones técnicas y d...

  3. Recondicionamiento de piezas de hierro fundido por tratamiento térmico (I Parte

    Directory of Open Access Journals (Sweden)

    Maria Elvira Font Pérez

    2008-01-01

    Full Text Available Se recoge una breve panorámica sobre la importancia que posee el incremento de volumen de material, en piezas de hierro fundido, a causas de los cambios estructurales que en las mismas provoca el tratamiento térmico. Se escoge como problema el desgaste que sufren algunos elementos del motor de combustión interna debido a la fricción, así como su recuperación empleando este método. Por otro lado se realiza un análisis a cerca de como influyen sobre las propiedades mecánicas principales de estos elementos, los factores principales del régimen del tratamiento térmico aplicado en su recuperación. Se dan las ventajas, que sobre otros métodos, posee el tratamiento térmico en el recondicionamiento de piezas de hierro fundido.

  4. Modelado de las Fuerzas de Corte en el Fresado de Piezas de Paredes Delgadas

    OpenAIRE

    2013-01-01

    En este trabajo se aborda el problema de la simulación de las fuerzas de corte en fresado cuando la pieza a mecanizar es flexible. Se presenta el desarrollo de un modelo matemático de tipo mecanicista que relaciona las fuerzas de corte y las deformaciones de la pieza durante la operación de fabricación. El énfasis del desarrollo de este modelo está puesto en la rapidez de cálculo de las fuerzas de corte. Esta característica facilitaría la implementación del modelo en sistemas de corrección de...

  5. Piezas muebles bajomedievales pertenecientes a la iglesia parroquial de Santiago de La Coruña

    Directory of Open Access Journals (Sweden)

    Barral Rivadulla, María Dolores

    1995-12-01

    Full Text Available Not available.

    Este trabajo tiene como intención fundamental rescatar parte del patrimonio perteneciente a la iglesia parroquial de Santiago de La Coruña, producción artística, tradicionalmente omitida, pero de gran importancia si se intenta analizar a través de la misma la religiosidad y el mundo que las rodea, como piezas manifestación de determinada devoción o creencia.

  6. Estructuras livianas a partir de piezas menores de madera de plantación

    Directory of Open Access Journals (Sweden)

    Aldo Ramírez Coretti

    2007-05-01

    Full Text Available Se presentan los resultados de un estudio exploratorio, parte de una serie de investigaciones conjuntas desarrolladas y en proceso de desarrollo, alrededor de esta temática. Su ejecución respondió, entre otras, a inquietudes presentadas por diversos productores de madera deplantación. El estudio consideró el diseño y fabricación de una máquina espigadora de piezas estructurales. También procuró explorar el potencial de aprovechamiento de piezas producto de raleos de madera de plantación para la fabricación de estructuras livianas. Se llevaron a cabo ensayos de uniones, de marcos simples con dos paneles de cerramiento comerciales, empleando cuatro especies de madera de plantación. También se llevó a cabo la fabricación de las piezas y montaje de una estructura modelo, empleando el equipo y otra información obtenida como resultado de la investigación. Los resultados muestran un gran potencial para el desarrollo de un sistema de construcción ágil y modular. Asimismo, las resistencias obtenidas sonadecuadas para las condiciones a que estarían expuestas las estructuras.

  7. Evaluación del grado de adecuación del proceso de forja en caliente para la fabricación de piezas estampadas: criterios de viabilidad y optimización

    Directory of Open Access Journals (Sweden)

    Arenas Reina, José Manuel

    2000-10-01

    Full Text Available The design of industrial parts is a clear example of integrative effort that, with a focus of several disciplines, requires a detailed analysis of the different scientific and technological knowledge implied in its conception and development. Inside this performance context, the present work approaches the problem of the project of hot forging parts, proposing the use of criteria of viability and optimization that, based in technical and economical considerations, allow to value the adjusting degree of various alternative to the forge process, facilitating with it the selection of the most appropriate. Fixed these bases and with object of shortening times of answer and analysis in an application corresponding to parts with revolution symmetry, a computerized system has been introduced that, taking as started data the design of the part, geometrically simulates the forge process, allowing to calculate the adaptation coefficients in those morphologing that are possible according to the criteria of viability criteria. This system also provides a graphic representation of machined part, the forged part and the finished stamp.

    El diseño de piezas industriales supone un claro ejemplo de esfuerzo integrador que, con un enfoque interdisciplinar, requiere un análisis detallado de los diferentes conocimientos científicos y tecnológicos implicados en su concepción y desarrollo. Dentro de este marco de actuación, el presente trabajo aborda la problemática del proyecto de piezas estampadas en caliente, proponiendo la utilización de criterios de viabilidad y optimización que, fundamentados en consideraciones técnico-económicas, permiten valorar el grado de adecuación de las diferentes alternativas al proceso de forja, facilitando con ello la selección de la más adecuada. Fijadas estas bases y con objeto de acortar tiempos de respuesta y análisis en una aplicación correspondiente a piezas axisimétricas, se ha introducido un sistema

  8. Algunas soluciones de estructuras de hormigón armado formadas por piezas premoldeadas

    Directory of Open Access Journals (Sweden)

    Fisac, Miguel

    1963-04-01

    repetición sea suficientemente amplia y, con ello, la ventaja económica se deje sentir respecto de otros métodos constructivos que no utilizan estos elementos previamente preparados; pero, actualmente, se presta gran atención a las formas arquitectónicas, lo cual requiere que las piezas o elementos prefabricados estén dentro del juego dimensional que un despiece de la forma exige. Pero este problema presenta su dificultad, porque la concepción de la forma, tiene como origen la resistencia y estabilidad, a los que estos elementos han de acoplarse. Otro aspecto particular de estos elementos se conjuga con su propia estructura y susceptibilidad, con objeto de dejarse moldear dentro de un proceso de industrialización que le proporcione una clara ventaja sobre los otros materiales. El transporte, acopio y manipulación de estos elementos estructurales prefabricados presenta, asimismo, sus problemas, ya que, en general, su concepción para formar un todo puede ser perfecto sin que, por ello, al considerar aisladamente un elemento, éste resulte frágil. Respecto a su colocación en obra, son también necesarios ciertos elementos de enganche para las grúas o máquinas de elevación que los han de llevar a su posición definitiva. Como puede apreciarse, estos elementos, si han de ser real eficaces y prestar ayuda notable en las realizaciones de obra tipo civil o arquitectónico, deberán reunir ciertas exigencias más cuyo ajuste y alcance requerirán especial cuidado y el, problema éste que el autor emprende y trata, de desarrollar con la esperanza de contribuir a no pocas aspiraciones de campo en que ha entrado y pretende descubrir el indudable práctico sentido de la prefabricación.

  9. Implementación de un procedimiento metodológico para la elaboración de piezas por bruñido con rodillo simple.

    Directory of Open Access Journals (Sweden)

    S. Díaz Rojas,

    2009-01-01

    Full Text Available En el presente trabajo se exponen los fundamentos y los resultados de investigaciones realizadas sobre la operación secundaria de acabado superficial de piezas conocida como bruñido por rodillo simple.Se abordan teóricamente las cuestiones más importantes de los procesos de deformación plástica superficial empleados para el mejoramiento de las cualidades superficiales de las piezas.Se realiza una investigación experimental en piezas simétrico-rotativas de acero AISI 1045 en un torno paralelo convencional con una herramienta de bruñir mono rodillo construida al efecto, donde se toman en consideración las variables más influyentes en el bruñido por rodillo simple: fuerza compresiva, avance y número de pasadas de la herramienta bruñidora. Se obtienen los modelos empírico-matemáticos que describen los efectos de estas variables en el incremento de la dureza y la calidad superficial final de la pieza, así como en la disminución del diámetro exterior y en la profundidad de la capa endurecida. Como resultado más importante de este trabajo, se desarrolla un procedimiento metodológico para la elaboración de piezas mediante este tipo de tratamiento mecánico por deformación plástica superficial, que permitirá la creación y difusión de una disciplina tecnológica sobre un proceso de fabricación que posee ventajas y que está poco difundido en las empresas metalmecánicas.In the present work the foundations and the results of the investigation for the secondary operation of superficial finish (single roller burnishing are presented. The most important aspects of the superficial plastic deformation process for improving superficial finish are approachedAn experimental investigation in symmetrical-revolving pieces of steel AISI 1045 in a conventional parallel lathe with a burnishing tool of single roller built to the effect is carried out. The most influential variables were took in consideration: compressive force, feed and number

  10. Diseño de una unidad de proceso para el tratamiento superficial (cromado y niquelado) de piezas de acero para automoción

    OpenAIRE

    2012-01-01

    El proyecto se centra en la desmineralización continua de aguas residuales de lavado para su posterior reutilización en baños de tratamiento superficial de piezas de acero para automoción. Concretamente se centra en tratar un número máximo de 300000 piezas anuales, 75 piezas diarias. Tratando un volumen máximo de 16 m3/h de agua residual procedente de los baños de tratamiento superficial de piezas de acero.

  11. El Seguro Popular de Salud en México: Pieza Clave de la Inequidad en Salud

    OpenAIRE

    Silvia Tamez González; Catalina Eibenschutz

    2008-01-01

    El objetivo central de este trabajo es presentar un análisis de la situación actual del Sistema Nacional de Salud mexicano, resultado de las sucesivas reformas realizadas desde la década de los ochenta. Interesa de manera especial, enfatizar el papel que ha jugado el Seguro Popular de Salud (SPS) como pieza clave de la mercantilización de la atención médica. Para tal efecto, en la primera parte se presentan los principales antecedentes de los cambios realizados durante las dos últimas décadas...

  12. Conceptos de diseño para manufactura (dfm) de piezas microfundidas

    OpenAIRE

    Cortés Rodríguez, Carlos Julio; Sánchez R, Claudia Marcela

    2010-01-01

    Una de las metodologIas utilizadas por la ingenierIa concurrente o diseno integrado de productos es el diseno para manufactura, DEM. Esta técnica, que está orientada a melorar la fabricación de piezas analizando geometrIas, valores y tolerancias, es utilizada en las primeras etapas de diseno para disminuir los costos de los elementos a fabricar. Se estudió el diseno para manufactura estableciendo reglas de diseno a fin de elaborar una metodologIa para diseno en microfundición.

  13. La estrategia del exceso : manifestaciones fantásticas en la pieza dramática Terraza con jardín infernal de Francisco Tario

    OpenAIRE

    Mejía González, Alejandro Adalberto

    2015-01-01

    El presente artículo tiene el objetivo de explicar cómo a través de una escritura del exceso se pone en crisis tanto el plano pragmático como el plano de la representación, para instaurar una estrategia de lo fantástico en la pieza dramática Terraza con jardín infernal del escritor mexicano Francisco Tario. Al inicio del artículo se problematiza la presencia del teatro fantástico en México, atendiendo el caso específico de la dramaturgia de Tario y los distintos puntos de contacto que tiene c...

  14. Evaluación de la calidad superficial de piezas mecanizadas a partir del análisis de la fuerza de corte

    Directory of Open Access Journals (Sweden)

    Sánchez-Carrillero, M.

    1998-05-01

    Full Text Available Surface quality is one of the most important criteria for establishing the optima cutting parameters needed to perform a machining process. Usually, the evaluation of the degree of the surface finishing requires to apply metrological techniques which involve times out in the production. As a consequence of this, a loss in both the economy of the process and the fiability of the tests reproducibility can be produced. In this work a relation between cutting force and surface roughness has been studied for the turning process of an Al-Cu alloy. From this relation, the surface quality of the machined samples can be evaluated by using the cutting forces values acquired during the cutting process.

    El grado de acabado superficial de una pieza mecanizada es uno de los factores determinantes a la hora de establecer los parámetros de corte necesarios para llevar a cabo el proceso de mecanizado. Generalmente, la evaluación de ese grado de acabado requiere la aplicación de técnicas metrológicas que conllevan paradas de máquina y, a menudo, extracciones de piezas. Este hecho provoca la aparición de una serie de efectos negativos, no sólo en lo que a pérdidas económicas se refiere, sino a fiabilidad en la reproducción de los ensayos. En el presente trabajo se ha estudiado la relación existente entre la fuerza de corte y la rugosidad superficial para una aleación Al-Cu. A partir de esta relación se puede evaluar la calidad superficial de las muestras mecanizadas mediante la determinación de las fuerzas de corte durante el proceso.

  15. Implicaciones industriales del endurecimiento por explosivos de piezas de acero Hadfield

    Directory of Open Access Journals (Sweden)

    Miguel A. Caraballo-Núñez

    2004-03-01

    Full Text Available El desgaste prematuro que sufren las piezas fabricadas de acero Hadfield en los equipos de laboreo minero de la industria cubana del níquel, limita la capacidad de trabajo de estos equipos. El trabajo expone los resultados alcanzados en el desarrollo y aplicación de un procedimiento tecnológico de endurecimiento, empleando las cargas de impacto generadas por la energía de detonación de una sustancia explosiva. Este procedimiento ha sido empleado en los dientes de la pala excavadora ESH-5/45 M utilizados en la extracción del mineral laterítico de la mina de la Empresa Comandante Ernesto Che Guevara en Moa, provincia Holguín, y en los martillos de las trituradoras de sínter M - 8 - 6B de la Planta de Calcinación y Sínter de la propia empresa. La utilización de tal procedimiento reportó un alargamiento equivalente a 1,5 y 2 veces de la vida útil de las piezas con su correspondiente efecto económico, social y ambiental.

  16. Diseño e implantación de un sistema de gestión de calidad para los procesos de fabricación de piezas de fibra de carbono

    OpenAIRE

    Gómez Vega, Francisco

    2005-01-01

    El objeto del proyecto es el diseño y la implantación del Sistema de Gestión de Calidad (EGC), para conseguir la ampliación de la certificación en base a la norma EN 9100:2003 de la empresa Easy Industrial Solutions (EIS), de modo que dicha certificación alcance al nuevo proceso productivo que la empresa desarrolla y que consiste en la fabricación de piezas de fibra de carbono de pequeño tamaño.

  17. Una nueva pieza de artilleria de galeras del siglo XVI: el esmeril bastardo «matacapitanes»

    Directory of Open Access Journals (Sweden)

    Fondevila Silva, Pedro

    2012-12-01

    Full Text Available This work is aimed at the analysis of an unknown piece of maritime artillery dated at the second half of the XVIth century. This piece, out of any inventory record, was located within one of the Archive-Museum chambers in the Don Álvaro Bazán Palace at El Viso del Marqués, Ciudad Real province, central Spain. The specimen is a bastard esmeril here so-called «matacapitanes» («killer of captains» because it seems precisely designed to be used against the bullet-proof armour of enemy officers. By means of manuscripts and impressed documents, an approach and discussion on the typology and classification of the XVIth century´s maritime artillery is also presented.

    Trabajo de investigación que presenta y analiza una pieza desconocida de artillería naval de la segunda mitad del siglo XVI, localizada sin inventariar en una de las salas del Archivo-Museo «Don Álvaro de Bazán» del Palacio de El Viso del Marqués en Ciudad Real (España. Se trata de un esmeril bastardo que hemos bautizado como «matacapitanes », por ser un modelo diseñado para optimizar su empleo contra los oficiales enemigos protegidos con armaduras a prueba de balas de arcabuz. Además, se realiza una aproximación al estudio de la tipología y clasificación de la artillería naval del siglo XVI a través de los documentos, tanto manuscritos como impresos, de esa época.

  18. Interpretación en arqueología : piezas de collar de una necrópolis navarra

    Directory of Open Access Journals (Sweden)

    Amparo Castiela Rodríguez

    2005-01-01

    Full Text Available Los restos de ajuar, recuperados en la necrópolis que han seguido el rito de la cremación, nos llegan muy alterados y requieren en ocasiones un esfuerzo especial para su comprensión. En el caso de varias piezas procedentes de La Atalaya, que formaban parte de collares, cuya interpretación ofrecemos

  19. Composites de bagazo de baja densidad para partes y piezas moldeadas para la industria automotriz

    Directory of Open Access Journals (Sweden)

    Manuel Serantes

    2006-01-01

    Full Text Available Se desarrolló un composite a partir del bagazo de la caña de azúcar, con características similares a una muestra entregada por la firma FAIST GmbH& Co. K.G. de Alemania, para ser empleado en la elaboración de partes y piezas moldeadas para la industria automotriz. Se estudian diferentes grados de molida. A los composites obtenidos se le determinaron las propiedades físico-mecánicas. Se realizó un análisis visual de su aspecto físico. Se presentan los resultados obtenidos, así como conclusiones y recomendaciones.

  20. Formulación material y espacial del modelo geometricamente exacto de piezas alargadas

    OpenAIRE

    2008-01-01

    El análisis de la respuesta mecánica de piezas alargadas que experimentan grandes desplazamientos y rotaciones constituye un campo en el que se han producido avances significativos en las tres últimas décadas, tanto desde el punto de vista de la formulación de modelos físicos como de la búsqueda de soluciones numéricas. El ámbito de aplicación de este tipo de modelos se separa quizás del abanico de problemas de los que tradicionalmente se ha ocupado la ingeniería civil, aproximándose más a si...

  1. Obtención del modelo tridimensional de una pieza de terracota mediante tecnología láser escáner 3D.

    OpenAIRE

    Pantoja Lorenzo, Ana

    2014-01-01

    El objetivo del presente Proyecto Fin de Carrera consiste en obtener el modelo tridimensional de una pieza de terracota, mediante la tecnología Láser Escáner 3D. Se plantea como objetivo de este proyecto el análisis del comportamiento del escáner y de la modelización 3D en relación a los tipos de materiales. Se realizarán ensayos con piezas construidas con materiales metálicos de mayor o menor complejidad y se concluirá con el estudio de la pieza de terracota seleccionada para este trab...

  2. Modelación por Elementos Finitos como Método para la Sustitución de Piezas de Acero por Hierro Nodular.

    Directory of Open Access Journals (Sweden)

    Mario Jacas

    2005-09-01

    Full Text Available Dado el nivel de aplicación que ha tenido en los últimos años la sustitución de piezas de acero por hierrofundido nodular, en este trabajo se establece una vía de análisis con el empleo de un software deElementos Finitos que justifique desde el punto de vista de las propiedades mecánicas de los elementoslas posibilidades de sustitución.El objetivo del presente trabajo es la sustitución de un tope de maquina hormigonera originalmentefabricado de componentes soldados de material AISI 1020 por uno rediseñado con hierro nodularaustemplado (ADI, utilizando la modelación por elementos finitos, sobre la base de un análisis linealestático.Finalmente, al comparar las tensiones de Von Mises y los desplazamientos originados por la acción de lacarga, se pudo observar un mejor comportamiento mecánico en el modelo rediseñado del tope de hierronodular austemplado (ADI.

  3. Caracterización metalúrgica de tres piezas arqueológicas de materiales base cobre procedentes del Bajo Aragón

    Directory of Open Access Journals (Sweden)

    Gabaldón, A.

    2006-08-01

    Full Text Available Three archaeological metallic objects corresponding to three different cultural times are studied. The objects are: a point of arrow Palmela type, a fragment of adze (possibly of the First Iron Age and a ring or small ring of the Roman Period. The analysis show concordant results whit similar finds of the same cronology and contribute new data about the metallurgical technology of the copper base material for each of the cultural times of origen. At the same time how has affected the environment in which the objects have been found has been determinate.

    Se estudian tres piezas metálicas arqueológicas correspondientes a tres momentos culturales diversos. Se trata de una punta de flecha tipo Palmela, de un fragmento de azuela (posiblemente de la Primera Edad del Hierro y de un anillo o anilla del período romano. Los análisis ofrecen resultados concordantes con los de objetos similares de la misma cronología y aportan datos nuevos sobre la tecnología metalúrgica de los materiales de base cobre para cada uno de los momentos culturales de procedencia. Al mismo tiempo, se ha determinado cómo ha afectado el medio en el que se hallaron a su estado de conservación.

  4. Estudio de las variables que afectan la rugosidad superficial en el torneado de piezas esbeltas bajo retemblado

    OpenAIRE

    2008-01-01

    El mecanizado de piezas delgadas se encuentra influenciado por un fenómeno denominado retemblado, que afecta la calidad superficial. En este trabajo se presenta un estudio de los factores que influyen sobre la rugosidad superficial en un proceso de torneado de cilindros esbeltos bajo el efecto del fenómeno de retemblado. El propósito del estudio es determinar cuales son las variables del proceso que más influyen sobre la rugosidad superficial. Para ello se utiliza un modelo que permite pred...

  5. La prospección de superficie en la caracterización de yacimientos: poblado protohistórico de Pieza Redonda en Lanciego (País Vasco

    Directory of Open Access Journals (Sweden)

    Rodríguez Fernández, J., Martínez Montecelo, A.

    2015-01-01

    Full Text Available Hoy día, nadie duda de la eficacia de la prospección superficial como herramienta de valoración, gestión y preservación del patrimonio arqueológico. Sin embargo, su verdadero alcance analítico y cognoscitivo no queda tan claro en la distinta bibliografía existente al respecto. Basándonos en la experiencia obtenida en el yacimiento de Pieza Redonda (Lanciego, Álava, el artículo pretende impulsar una reflexión en torno a las posibilidades, problemáticas y desarrollo teórico-metodológico de la inspección visual dentro de la Arqueología, lo que conlleva necesariamente en nuestra opinión una revisión de conceptos tales como territorio, paisaje y yacimiento.

  6. Metodología para la evaluación y análisis de la precisión en piezas de fabricación aditiva

    OpenAIRE

    2014-01-01

    En el presente proyecto se desarrolla una metodología para la evaluación y análisis de la precisión en piezas de fabricación aditiva. Esta metodología ha sido diseñada especialmente para las tecnologías de fabricación aditiva que utilizan materiales poliméricos y en especial, las diseñadas para la realización de prototipos funcionales. En el primero de los bloques en los que se divide el proyecto se trata de situar al lector en el tipo de tecnologías que utilizan materiales poliméricos en ...

  7. Salvar al soldado Ryan con 300 espartanos: historia, memoria, mito

    OpenAIRE

    Pérez García, Juan Carlos

    2012-01-01

    El presente artículo tiene por objeto indagar en los temas de la construcción de la memoria, el mito y la tradición oral, tal como se han proyectado en dos películas recientes de gran impacto internacional, principalmente 300 (2007, Zack Snyder) y Salvar al Soldado Ryan (1998, Steven Spielberg). También pretendemos explorar las innovaciones que las técnicas del nuevo cine digital están aportando a estas mitologías contemporáneas. The present paper addresses the issues of construction of me...

  8. EFECTO DEL ÁCIDO CLORHÍDRICO Y LA TEMPERATURA EN LA MORFOLOGÍA DE PIEZAS DENTARIAS SANAS. AREQUIPA. 2014

    OpenAIRE

    LOVÓN QUISPE, WASHINGTON EDWARD

    2015-01-01

    TABLAS DE MORFOLOGIA DE LAS PIEZAS DENTARIAS SANAS SOMETIDAS A LA ACCION DEL ACIDO CLORHIDRICO TABLAS DE MORFOLOGIA DE LAS PIEZAS DENTARIAS SANAS SOMETIDAS A LA ACCION DE LA TEMPERATURA LA IDENTIFICACIÓN FORENSE LOS DIENTES ELEMENTOS ARQUITECTÓNICOS DE LOS DIENTES ESTRUCTURA DEL DIENTE EL ESMALTE CARACTERÍSTICAS GENERALES DEL ESMALTE ESTRUCTURA DEL ESMALTE LA DENTINA CARACTERÍSTICAS GENERALES DE LA DENTINA COMPOSICIÓN QUÍMICA DE LA DENTINA EL CEMENTO EL ÁCIDO CLORHÍDRICO RIESGOS DEL ÁCIDO CLO...

  9. Estudio de la viabilidad en la impresión en 3D de piezas poliméricas para elevadores

    OpenAIRE

    HARO MARTÍ, ALEJANDRO

    2016-01-01

    [ES] Se realizara el estudio de la viabilidad del uso de la impresión 3D en la sustitución de determinadas piezas utilizadas en instalaciones elevadoras. El estudio abarca desde la selección de la pieza polimérica a sustituir. Estudio de los esfuerzos a los que se ve implicada. Estudio del material empleado y su posible sustitución. Estudio del empleo del proceso de impresión 3D en los posibles materiales disponibles. Estudio económico. Haro Martí, A. (2016). Estudio de la viabilidad en la...

  10. Fabricación de piezas de vidrio mediante la ruta de procesado de moldeo por inyección de polvos

    OpenAIRE

    Berzal Nogales, Daniel

    2009-01-01

    En el presente Proyecto Fin de Carrera se ha llevado a cabo un estudio para determinar la posibilidad de utilizar la ruta de procesado denominada moldeo por inyección de polvos (PIM) como técnica de fabricación de piezas de vidrio. A su vez, se ha comprobado si es factible reciclar los botes de vidrio que se utilizan comúnmente en la industria alimentaria mediante este procedimiento. Con este objetivo, se han analizado y optimizado cada uno de los pasos necesarios para la fabricación de pieza...

  11. Génesis y evolución del golf : de fragmento de paisaje a pieza de ordenación del territorio. Incidencia de los campos de golf en la conformación del espacio turístico Costa del Sol

    OpenAIRE

    2014-01-01

    La Costa del Sol inició un intenso proceso de desarrollo y expansión a partir de los años cuarenta, cuando la ideología del crecimiento se consolidaba como motor económico, derivado de la proyección de nuevos usos sobre el soporte. Sobre un territorio-matriz previo, inmenso y casi vacante, mínimamente estructurado mediante pequeños núcleos históricos conectados por el eje de la costa, fueron precipitando nuevas piezas como consecuencia del uso turístico que se añadió al territorio. Este proc...

  12. D1.\tos piezas que surgieron como una, o de una peculiar captura de inspiraciones musicales: recuento de un inusual proceso creativo

    Directory of Open Access Journals (Sweden)

    Johann Hasler

    2013-04-01

    Full Text Available Este escrito da cuenta del proceso de investigación-creación que supuso la obra “dos piezaspara clarinete y para piano”, compuestas durante el curso de composición avanzada delDartington International Summer School (Devon, Inglaterra en julio de 2004 (Con financiacióncompleta para el compositor por parte de la Fundación Hinrichsen para la promoción dela música http://www.hinrichsenfoundation.org.uk/, último acceso el 19 de enero de 2012. Lapeculiaridad de esta obra radica en que al compositor le queda la duda, aún años después desu composición y estreno, de si se trata de una obra para dos instrumentos o dos obras parainstrumento solo que pueden tocarse simultáneamente. Es decir, el compositor no tiene lacerteza de si son dos obras o una sola: su idea y su “inspiración” sobre la obra le indican unidad(se le ocurrieron simultáneamente, pero su análisis y deconstrucción formal indican que setrata de dos piezas separadas. Surgen así interesantes tensiones entre teoría y práctica, entreentender la composición como construcción o como inspiración, entre el trabajo creativo mentaly el intuitivo, la percepción inmediata y los trasfondos, las diferencias entre el origen y el destinoo presentación de las obras, etc.

  13. Identificación de asimetrías bilaterales en piezas y cortes porcionados comerciales de canales de bovino procesadas en Guadalajara, Jalisco, México

    Directory of Open Access Journals (Sweden)

    J. M. Zorrilla

    2011-01-01

    Full Text Available Se identifica la presencia de asimetrías entre el lado izquierdo y el derecho en canales de bovino faenadas en el Rastro Municipal de Guadalajara, Jalisco (México, a partir de la comparación de tres piezas primarias, 30 porcionados comerciales y siete componentes anatomo-estructurales, diferencias agrupadas arbitrariamente en un origen de carácter anatómico, de índole mecánico por el proceso físico de su división y la posible combinación de ambos. El análisis de los datos generados de 20 canales permitió identificar que el riñón, la grasa de la riñonada y el sebo fueron estructuras anatómicas con pesos estadísticamente diferentes (P<0.0178; P<0.0183; P<0.0944, respectivamente cuando se compararon los correspondientes pares izquierdo y derecho. La bandera, el contrapecho, el diezmillo, el pescuezo y el recoveco fueron cortes porcionados estadísticamente diferentes (P<0.0005; P<0.0817; P<0.0859; P<0.0387; P<0.0178, respectivamente cuyo origen se puede adjudicar a factores anatómicos y, posiblemente, mecánicos al momento de su separación física. La única estructura estadísticamente diferente (P<0.0001 entre ambos lados -considerada producto de una influencia de la operación mecánica durante su separación- fue el cuarto anterior de la canal. Estos resultados apoyan la sugerencia de establecer un solo lado de la canal de bovinos en la implementación de normas y sistemas de clasificación, por calidades y rendimientos.

  14. Implementación de un procedimiento metodológico para la elaboración de piezas por bruñido con rodillo simple // Implementation of a methodological procedure for parts elaboration by single roller burnishing.

    Directory of Open Access Journals (Sweden)

    S. Díaz-Rojas

    2009-01-01

    Full Text Available En el presente trabajo se exponen los fundamentos y los resultados de investigaciones realizadas sobrela operación secundaria de acabado superficial de piezas conocida como bruñido por rodillo simple.Se realiza una investigación experimental en piezas simétrico-rotativas de acero AISI 1045 en un tornoparalelo convencional con una herramienta de bruñir mono rodillo construida al efecto, donde setoman en consideración las variables más influyentes en el bruñido por rodillo simple: fuerzacompresiva, avance y número de pasadas de la herramienta bruñidora. Se obtienen los modelosempírico-matemáticos que describen los efectos de estas variables en el incremento de la dureza y lacalidad superficial final de la pieza, así como en la disminución del diámetro exterior y en laprofundidad de la capa endurecida. Como resultado más importante de este trabajo, se desarrolla unprocedimiento metodológico para la elaboración de piezas mediante este tipo de tratamientomecánico por deformación plástica superficial, que permitirá la creación y difusión de una disciplinatecnológica sobre un proceso de fabricación que posee ventajas y que está poco difundido en lasempresas metalmecánicas.Palabras claves: bruñido por rodillo simple, deformación plástica superficial, dureza superficial, rugosidadsuperficial, acero AISI 1045.___________________________________________________________________________AbstractIn the present work the foundations and the results of the investigation for the secondary operation ofsuperficial finish (single roller burnishing are presented. The most important aspects of the superficialplastic deformation process for improving superficial finish are approachedAn experimental investigation in symmetrical-revolving pieces of steel AISI 1045 in a conventionalparallel lathe with a burnishing tool of single roller built to the effect is carried out. The mostinfluential variables were took in consideration: compressive

  15. Metodología para el cálculo de espesores límite libres de fase sigma durante el hipertemple en piezas de aceros dúplex de gran sección

    Directory of Open Access Journals (Sweden)

    Jimbert, P.

    2013-04-01

    embargo, al aumentar la profundidad a la que se encuentran los yacimientos actuales, los espesores para este tipo de canalizaciones se han visto incrementados, lo que se traduce en mayores niveles de exigencia sobre todo su proceso de fabricación, incluyendo el tratamiento térmico. Para evitar la precipitación de estas fases intermetálicas, como la fase sigma, es necesario conocer el perfil de enfriamiento en el centro de la pieza y para ello, conocer el valor del Coeficiente de Transferencia de Calor Superficial (h es fundamental. Dicho coeficiente varía durante el hipertemple y su valor se determina experimentalmente ya que depende de varios parámetros del proceso. Diversos estudios demuestran que su valor se estabiliza a los pocos segundos, por lo que para conocer el perfil de enfriamiento en el centro de grandes secciones bastaría con conocer el valor estabilizado de h. Sin embargo, los estudios existentes en la literatura se refieren a diámetros menores de 100 mm. En el presente trabajo se ha desarrollado una metodología para predecir la precipitación de fases intermetálicas en piezas de acero dúplex con grandes espesores en instalaciones industriales a partir del cálculo de h. Esta metodología nos permite calcular los perfiles de enfriamiento sin sacrificar ninguna pieza, utilizando una o varias piezas patrón sensorizadas con termopares y una simulación posterior mediante ANSYS.

  16. Estudio comparativo de la efectividad antibacteriana de la asociación de clorhexidina al 2%, de hidróxido de calcio, puntas de hidróxido de calcio y puntas de clorhexidina frente al Enterococcus faecalis

    OpenAIRE

    2007-01-01

    Objetivo: evaluar el efecto antibacteriano sobre el Enterococcus faecalis, de una pasta de clorhexidina al 2% con hidróxido de calcio, puntas de hidróxido de calcio y las puntas de diacetato de clorhexidina, y determinar cuál de ellas es la mejor alternativa de elección en el tratamiento de conductos de piezas dentarias con diagnóstico de necrosis pulpar. Material y Método: la muestra fue tomada de 60 piezas dentarias unirradiculares con diagnóstico de necrosis pulpar, con presencia de fístul...

  17. El intestino: pieza clave del sistema inmunitario The bowel: A key component of the immune system

    Directory of Open Access Journals (Sweden)

    E. Ramiro-Puig

    2008-01-01

    Full Text Available El intestino se halla expuesto constantemente a una elevada carga antigénica procedente de la dieta y de bacterias comensales. El tejido linfoide asociado al intestino (Gut-Associated Lymphoid Tissue, GALT constituye la parte más extensa y compleja del sistema inmunitario y es capaz de discriminar de forma eficaz entre patógenos invasivos y antígenos inocuos. El conocimiento de su particular subdivisión en tejido organizado, inductor de la respuesta inmunitaria (placas de Peyer y ganglios linfáticos mesentéricos, y tejido difuso, efector de la respuesta inmunitaria (linfocitos intraepiteliales y linfocitos de lámina propia, nos permite comprender cómo se desarrolla y regula la respuesta inmunitaria en el intestino y como esta puede extenderse al resto del organismo.The gut is constantly exposed to a high antigenic load coming from the diet and commensal bacteria. The Gut-Associated Lymphoid Tissue (GALT constitutes the most extensive and complex part of the immune system and is capable of efficiently distinguishing invasive pathogens from innocuous antigens. The knowledge of its unique structure consisting on organised tissue, inductor of the immune response (Peyer's patches and mesenteric lymph nodes, and diffused tissue, effector of the immune response (intraepithelial lymphocytes and lamina propria lymphocytes, allow us to understand the development and regulation of the immune response in the gut and how this one can be extended to the rest of the organism.

  18. Piezas de arte tradicional a través de pantallas

    Directory of Open Access Journals (Sweden)

    Panozzo Zenere, Alejandra

    2014-01-01

    Full Text Available [es] El objetivo de este artículo es reflexionar sobre la producción de sentido al contemplar una obra de arte desde un espacio físico y a través de una pantalla. Esta problemática será analizada a partir de la pérdida de materialidad en un tipo de producción tradicional que se conforma como imagen digital, y le permite ser reproducida a través del dispositivo mencionado.Se trata de señalar, cómo el arte de caballete u objetual se conforma como un nuevo producto artístico a causa de las lógicas que plantea la digitalización.

  19. Experiencias en Cuba de la producción de piezas fundidas de fundición gris esferoidal (FGE, un material de elevadas cualidades y propiedades.

    Directory of Open Access Journals (Sweden)

    Francisco Mondelo García

    2005-09-01

    Full Text Available El trabajo expone alternativas posibles de acceder a fabricar fundiciones grises esferoidales(FGE, así como conocimientos, experiencias y métodos empleados en su producción en Cuba,contando por lo tanto con un material de elevadas cualidades y propiedades tecnológicas enexplotación. Se dan materiales básicos utilizados en los procesos de obtención de la FGE, locual incluye el proceso de recarburación de estas aleaciones ferrosas, más las operaciones denodulización e inoculación, junto a los controles bases en sus operaciones fundamentales, parafabricar piezas con la calidad y certificación requeridas. Se tienen resultados experimentalesproductivos de estas fundiciones nodulares, con marcas de diversas estructuras, propiedadesmecánicas y composiciones. Se valora además resultados de la sustitución de piezas deaceros por FGE con posibilidades de obtener, por tratamiento térmico los hierrosaustemperados (ADI y elementos económicos comparativos de la factibilidad de fabricación dela fundición sintética en piezas FGE con chatarras de aceros básicamente y recarburantesnacionales de carbón vegetal, como variante alternativa.

  20. Teoría y práctica de la estética expresionista en dos piezas de Carlos Muñiz

    OpenAIRE

    Pérez Jiménez, Manuel

    2005-01-01

    Estudio de las piezas breves "El caballo del caballero" y "Los infractores", escritas respectivamente en 1965 y 1969 por el dramaturgo español contemporáneo Carlos Muñiz, las cuales muestran una perfecta coherencia con el conjunto de la creación teatral del autor y, a la vez, un carácter paradigmático respecto a la estética en que dicha obra se inscribe, esto es, la vanguardia expresionista. El análisis de las mismas es realizado mediante la aplicación de los principios esenciales que art...

  1. Características clínicas periodontales de piezas con diagnóstico de trauma de oclusión secundario

    OpenAIRE

    Torres-Cárdenas, Yessica Janeth; Editor Administrativo. Área de Publicaciones Científicas, Universidad Peruana Cayetano Heredia.Lima; Chávez-Reátegui, Beatriz Del Carmen; Manrique-Chávez, Jorge Enrique

    2016-01-01

    Objetivos: Determinar las características periodontales de piezas con diagnóstico de trauma de oclusión secundario en pacientes atendidos en la Clínica Dental Docente de la Facultad de Estomatología “Roberto Beltrán” de la Universidad Peruana Cayetano Heredia durante los años 2011-2012. Material y métodos: Estudio retrospectivo, descriptivo, observacional y de corte transversal, con un universo conformado por pacientes con características clínicas de trauma de oclusión secundario recibidos po...

  2. Optimización de proceso de fabricación de piezas composite aeronáuticas fabricadas con tejido preimpregnado y curado en autoclave

    OpenAIRE

    2015-01-01

    En un proyecto actual en aeronáutica, existen problemas con los tiempos de ciclo en la fabricación de una determinada pieza. Mediante la observación de los procesos de fabricación y con la realización de mediciones de tiempos, se realiza un análisis de los mismos y se identifican los aspectos susceptibles de corrección y mejora. Finalmente, con los análisis efectuados, se aplican diversas técnicas de ingeniería de calidad para plantear posibles propuestas de corrección y mejora en los pro...

  3. Estudio de la transformación martensítica, optimización de la microestructura y prevención de la rotura frágil en piezas coladas de acero X38CrMoV5-1 de alta resistencia

    OpenAIRE

    Pastor Muro, Ana

    2016-01-01

    La presente tesis trata sobre el "Estudio de la transformación martensítica, optimización de la microestructura y prevención de la rotura frágil en piezas coladas de acero X38CrMoV5-1 de alta resistencia”. El acero X38CrMoV5-1/AISI H11 es un acero martensítico al cromo-vanadio-molibdeno para trabajo en caliente fácilmente endurecible, que se fabrica generalmente por moldeo con la consiguiente presencia de porosidad interdendrítica. La primera parte de la tesis consiste en una introducción don...

  4. « On travaille à la seconde! » Rémunération à la pièce et santé et sécurité du travail dans une perspective qui tient compte de l’ethnicité et du genre “We work by the second!” Piecework remuneration and occupational health and safety from an ethnicity- and gender-sensitive perspective «Trabajamos al Segundo!» Remuneración por pieza y salud y seguridad en el trabajo en una perspectiva que toma en cuenta la etnicidad y el género

    Directory of Open Access Journals (Sweden)

    Karen Messing

    2008-05-01

    Full Text Available Peu d’études qualitatives ont décrit les mécanismes par lesquels le travail à la pièce influence la santé. Nous présentons les résultats de 25 entrevues réalisées entre 2004 et 2006 dans une grande entreprise de fabrication de vêtements à Montréal. Nous décrivons la main- d’œuvre, constituée en grande majorité de femmes et d’immigrants, les exigences et contraintes de production, les stratégies des travailleurs et travailleuses favorisant la production et celles favorisant la santé, et la gestion et l’impact des problèmes de santé vécus au travail. De plus, nous confrontons la réalité du travail à la pièce à la représentation que s’en font différents intervenants (employeurs, travailleurs, travailleuses décideurs, médecins telle qu’elle a été rapportée dans 62 décisions sur des réclamations pour lésion professionnelle rendues par la Commission des lésions professionnelles (C.L.P. entre 2000 et 2007, décisions portant sur l’industrie du vêtement et mentionnant le travail à la pièce. Nous examinons les causes et discutons des implications de nos résultats.Few qualitative studies have described the mechanisms by which piecework influences health. We present the results of 25 interviews conducted between 2004 and 2006 in a large garment factory in Montreal. We describe the workforce, made up in large part of women and immigrants, the requirements and constraints of production, workers’ strategies favouring production and those favouring health, and the management and impact of the health problems experienced by workers. In addition, we compare the experience of piecework to its representation by various stakeholders (employers, workers, decision-makers, doctors as reported in 62 decisions regarding compensation claims for work-related health problems rendered by the Commission des lésions professionnelles (C.L.P. between 2000 and 2007, decisions pertaining to the garment industry and

  5. “We work by the second !” Piecework remuneration and occupational health and safety from an ethnicity- and gender-sensitive perspective « On travaille à la seconde ! » Rémunération à la pièce et santé et sécurité du travail dans une perspective qui tient compte de l’ethnicité et du genre « Trabajamos al Segundo ! » Remuneración por pieza y salud y seguridad en el trabajo en una perspectiva que toma en cuenta la etnicidad y el género

    Directory of Open Access Journals (Sweden)

    Karen Messing

    2008-05-01

    Full Text Available Few qualitative studies have described the mechanisms by which piecework influences health. We present the results of 25 interviews conducted between 2004 and 2006 in a large garment factory in Montreal. We describe the workforce, made up in large part of women and immigrants, the requirements and constraints of production, workers’ strategies favouring production and those favouring health, and the management and impact of the health problems experienced by workers. In addition, we compare the experience of piecework to its representation by various stakeholders (employers, workers, decision-makers, doctors as reported in 62 decisions regarding compensation claims for work-related health problems rendered by the Commission des lésions professionnelles (C.L.P. between 2000 and 2007, decisions pertaining to the garment industry and mentioning piecework. We examine the causes and discuss the implications of our results.Peu d’études qualitatives ont décrit les mécanismes par lesquels le travail à la pièce influence la santé. Nous présentons les résultats de 25 entrevues réalisées entre 2004 et 2006 dans une grande entreprise de fabrication de vêtements à Montréal. Nous décrivons la main- d’œuvre, constituée en grande majorité de femmes et d’immigrants, les exigences et contraintes de production, les stratégies des travailleurs et travailleuses favorisant la production et celles favorisant la santé, et la gestion et l’impact des problèmes de santé vécus au travail. De plus, nous confrontons la réalité du travail à la pièce à la représentation que s’en font différents intervenants (employeurs, travailleurs, travailleuses décideurs, médecins telle qu’elle a été rapportée dans 62 décisions sur des réclamations pour lésion professionnelle rendues par la Commission des lésions professionnelles (C.L.P. entre 2000 et 2007, décisions portant sur l’industrie du vêtement et mentionnant le travail à la

  6. Análisis microbiológico antes y después de la utilización de la pieza de mano de uso odontológico

    OpenAIRE

    Reyes Saberbein, Jorge; Rodríguez Torres, Luis; Fernández Reyes, Meylin; Iparaguirre Carbajal, Janeth; Montalvo Meléndez, Williams; Bravo Morocho, Karen; Guardia Quispe, Allison; Pino Guerrero, Fiorella

    2012-01-01

    Objetivo. Evaluar la condición microbiológica antes y después del uso de la pieza de mano en pacientes atendidos en la clínica odontológica de la USMP. Material y métodos. Estudio de tipo descriptivo, prospectiva, longitudinal. Se utilizaron 16 piezas de mano de la clínica especializada en odontológica de la USMP, como medio de cultivo se usó el Agar sangre para observar las diferentes clases de microorganismos presentes. Resultados. Las muestras esterilizadas en autoclave, sembradas...

  7. La fase del Ibérico final en el asentamiento del Torrelló del Boverot (Almazora, Castellón: dos piezas cerámicas singulares

    Directory of Open Access Journals (Sweden)

    Clausell, Gerardo

    2000-12-01

    Full Text Available Since the end of 1988, when excavation was resumed at the Torrelló del Boverot site in Almazora (Castellón, large amounts of material —mostly ceramics— have been recovered, dating from the end of the Iberian period, which, chronologically, marked the end of the village's life. This paper discusses two unusual ceramic pieces from this late period, documented during the excavations that took place in 1995, undertaken in the central area of the site. The records obtained in this work matches that of a batch of materials donated to the Museum of Almazora by the amateurs who excavated this village in the mid-1970s.Desde finales de 1988, cuando se retoman las campañas de excavación en el yacimiento del Torrelló del Boverot de Almazora (Castellón, se recuperaron abundantes materiales —fundamentalmente cerámicos— del periodo Ibérico final que cierra cronológicamente la vida del poblado. En este trabajo presentamos dos piezas cerámicas singulares correspondientes a esta fase tardía, documentada a través de la campaña de excavación llevada a cabo en 1995, en la que se trabajó en el área central del asentamiento. El registro obtenido en esta intervención coincide con el proporcionado por un lote de materiales donados al Museo de Almazora por parte de los aficionados que excavaron este poblado a mediados de la década de los setenta.

  8. Moniliophthora roreri (Cif y Par Evans et al. en el cultivo de cacao

    Directory of Open Access Journals (Sweden)

    Fernando David Sánchez Mora

    2012-01-01

    Full Text Available Más de un siglo, el cacao (Theobroma cacaoL. en el Ecuador ha sido fuente importante de ingresos para losagricultoresy de divisas para el país, llegando a ser uno de los exportadores más grandes a nivel mundial.Posteriormente, perdió paulatinamente ese estatus debido al ataque de enfermedades, entre ellas la moniliasiscausada por [Moniliophthoraroreri(Cif y ParEvanset al.]. Esta enfermedad puede causar daños hasta del80% en la producción. Actualmente no existe mucha información actualizada y científica, sobre su ocurrencia,sintomatología, etiología, epidemiología, ciclo de vida y manejo o estrategias de controlde la mencionadaenfermedad, por la tanto se realiza esta revisión con estos tópicos importantes, aportando con esto a esta áreadel conocimiento.

  9. Aproximación al estudio de unos colgantes aparecidos en Las Hurdes

    Directory of Open Access Journals (Sweden)

    María Carmen SEVILLANO SAN JOSÉ

    2009-11-01

    Full Text Available RESUMEN: Se estudian unas curiosas piezas aparecidas en Las Hurdes, unos colgantes, que tienen como característica común una serie de muescas que rodean las piezas y unas oquedades de diferente profundidad que forman dibujos geométricos, para las que es difícil establecer una cronología, aunque parece posible una atribución al período Calcolítico.ABSTRACT: A short of peculiar pieces found in Las Hurdes are studied. The hangings have as a common character a series of notches around, and some holes of different depth drawing geometrical forms. The chronology is difficult to stablish but it seems possible to ascribe it to the Calcolithic period.

  10. Optimización del diseño con algoritmos genéticos y metamodelos en la minimización del peso en piezas obtenidas mediante fabricación aditiva

    OpenAIRE

    2012-01-01

    Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI) [ES] Método de optimización para minimizar el peso de piezas aligeradas con estructuras celulares para fabricación aditiva.

  11. Influencia de la formulación de la arena en verde en su difusividad térmica y su efecto en una pieza colada

    Directory of Open Access Journals (Sweden)

    Noguez, M. E.

    2005-12-01

    Full Text Available Data evidencing a relation among green sand formulations (% water/% bentonite, w/b, in the ranks 0.2-0.55 for 6, 7, 8 and 9 % bentonite, their heat transfer behaviour, specifically their thermal diffusivity, the casting solidification rate and the resulting macrostructures in aluminium castings are presented.

    Se presentan evidencias de que la formulación de una arena en verde (relación entre los porcentajes de agua y de bentonita, a/b, en el rango 0,2-0,55 para 6, 7, 8 y 9 % de bentonita parece determinar su transferencia de calor y, por tanto, su coeficiente de difusividad térmica, lo que influye en la rapidez de solidificación y en las macroestructuras de piezas coladas en aluminio.

  12. Del espacio público al espacio lúdico

    OpenAIRE

    Acebedo Restrepo, Luis Fernando; Rodriguez Zambrano, Franco; Ruales, Jesús Ricardo

    2008-01-01

    La problemática planteada en este trabajo de investigación permite confrontar el tránsito del  espacio  público al espacio lúdico y las posibilidades de una propuesta urbana que responda a las expectativas del lugar y las necesidades ambientales, sociales y culturales según los aspectos encontrados en el trabajo teórico – conceptual. El proceso permitió explorar, por un lado una propuesta de “Sistema de Espacio Público” a nivel de la Pieza Urbana Ladera Norte en la comuna  5 de Manizales; por...

  13. Camino al cielo o al infierno

    OpenAIRE

    García Barrientos, José Luis

    2011-01-01

    Seguramente Juan Mayorga es hoy el dramaturgo mejor situado para presidir el teatro de la primera mitad del siglo XXI en España. Aun habiendo logrado antes éxitos tan rotundos como el de Cartas de amor a Stalin (1998), su consagración llega con la pieza que ahora se ofrece en Costa Rica.

  14. Tres piezas de metalistería prerromana en la colección Fontaneda (castillo de Ampudia, Palencia)

    OpenAIRE

    Sanz Mínguez, Carlos; Escudero Navarro, Zoa; Fontaneda Berthet, Cristina

    1996-01-01

    Producción Científica Un broche de bronce chapado en lámina de oro, un puñal de tipo Monte Bernorio con los primeros damasquinados introducidos en este arma y una fíbula de doble resorte de puente en cruz, todos ellos conservados en la colección Fontaneda, son objeto de análisis.

  15. Aproximación al patrimonio fotográfico: tres acciones participativas

    OpenAIRE

    Forero Murillo, Clara Victoria

    2014-01-01

    Este trabajo presenta el análisis de tres experiencias en las que la imagen fotográfica es el eje en común y la participación de los ciudadanos o de quienes se vinculan al proyecto desempeña un papel importante porque sus testimonios son piezas claves en la identificación del material visual. El apoyo de estos ciudadanos y su contacto con las imágenes, hace que ellos reconozcan la importancia de este material fotográfico, que al entrar en una plataforma que visibilice diferente...

  16. Microscopios del siglo XVIII del Museo Nacional de Ciencias Naturales. CSIC. Dos piezas únicas de la Ilustración para la investigación naturalista

    Directory of Open Access Journals (Sweden)

    González-Alcalde, Julio

    2010-10-01

    Full Text Available The objective of this work is to make a journey the history, characteristics and process of restoring of two of the oldest pieces in the Collection of the Technology and Industrial Archeology from the National Museum of Natural Sciences. CSIC. They are two microscopes from the eighteenth century, built in England. The simple-compound microscope, built by George Adams around 1750-1770, might have belonged to Don Antonio de Ulloa or Don Pedro Franco Dávila. Only two similar pieces are displayed in the Science Museum in Geneva and London. The compound microscope, built by Dollond in the 1780s, was owned by Eugenio Izquierdo de Rivera y Lazaún successor of D. Pedro Franco Dávila in the direction of the Royal Cabinet of Natural History. He was a well-known naturalist as well as a judge, diplomat, secretary and informant of Manuel Godoy.

    El objetivo de este trabajo es efectuar un recorrido por la historia, características y proceso de restauración de dos de las piezas más antiguas de la Colección de Arqueología de la Técnica e Industrial del Museo Nacional de Ciencias Naturales. CSIC. Son dos microscopios del siglo XVIII, construidos en Inglaterra. El microscopio simple-compuesto, construido por George Adams hacia 1750-1770 pudo pertenecer a D. Antonio de Ulloa o a Don Pedro Franco Dávila. Sólo se exponen dos piezas semejantes en el Museo de la Ciencia de Ginebra y en el de Londres. El microscopio compuesto, construido por Dollond hacia 1780, fue propiedad de Eugenio Izquierdo de Rivera y Lazaún sucesor de D. Pedro Franco Dávila en la dirección del Real Gabinete de Historia Natural, actual Museo Nacional de Ciencias Naturales. Era un conocido naturalista y, además, juez, diplomático, secretario e informante de Manuel Godoy.

  17. Piezas de mobiliario y decoración en escayola intarsiada, firmadas por Antonio y Vicente Marzal

    Directory of Open Access Journals (Sweden)

    Gutiérrez Pastor, Ismael

    2009-03-01

    Full Text Available A first approach to the study of inlay plasterwork (Italian scagliola in Spain, and the Marzal brothers, Valencian artists active during the first half of the 19th century who worked for Carlos IV and Fernando VII.

    Primera aproximación al estudio de la escayola (“scagliola” en España y a los hermanos Marzal, artistas valencianos de la primera mitad del siglo XIX que trabajaron para los reyes Carlos IV y Fernando VII.

  18. Espectroscopía de Plasmas Inducidos por Láser (LIBS) aplicada a la caracterización de piezas únicas y productos de interés industrial

    OpenAIRE

    Alvira, Fernando Carlos

    2010-01-01

    La Espectroscopia de Plasmas Inducidos por Láser (LIBS) es una técnica espectroscópica que se basa en la generación de plasmas por ablación láser. En esta tesis se desarrolló e implementó la técnica LIBS para la determinación de la composición de superficies y sustratos de productos industriales y piezas únicas de interés patrimonial. Se aplicó la técnica desarrollada para la caracterización de la composición de piezas sometidas a tratamientos superficiales, para la determinación de elementos...

  19. Asimetría de piezas de canales de bovino faenadas en el rastro municipal de Guadalajara, Jalisco, México

    Directory of Open Access Journals (Sweden)

    R. J. M. Zorrilla

    2010-01-01

    enteros, procesados en el rastro municipal de Guadalajara, Jalisco, México. Como criterio de evaluación se adoptó el grado de desviación de un valor de uno del coeficiente de correlación de Pearson del producto-momento. Los resultados mostraron la posible existencia de asimetrías de índole anatómico entre el lado derecho y el izquierdo de la cantidad de grasa de la riñonada y grasa pélvica, así como el área del ojo de la costilla, las cuales mostraron una correlación de 0.7102, 0.7704, 0.7649, respectivamente. Estos coeficientes de correlación son inferiores a los obtenidos para la comparación de los pesos de los segmentos derecho e izquierdo delanteros y traseros, de 0.9705 y 0.9587, respectivamente; lo que permite suponer que en las condiciones en que se llevó a cabo el presente trabajo, el proceso mecánico de cuarteo de las canales no alteró la simetría entre las piezas. Se señalan las posibles implicaciones que estos factores pueden tener en la construcción de un modelo matemático de predicción de cortabilidad de una canal de bovino.

  20. Estudio Experimental de Piezas Lineales de Hormigón Reforzadas con Fibras de Carbono Experimental Study of Reinforced Concrete Beams Strengthened with Carbon Fibers

    Directory of Open Access Journals (Sweden)

    M. Valcuende

    2004-01-01

    Full Text Available Se ha estudiado el comportamiento de seis vigas reforzadas simultáneamente con láminas y tejidos de fibra de carbono. Se analiza, para este tipo de refuerzos, la validez de dos de los métodos de cálculo posiblemente más utilizados. En ambos métodos se plantean las ecuaciones de equilibrio de fuerzas y momentos, pero se introducen suposiciones diferentes: i el acero tiene suficiente capacidad plástica para no romperse y ii el agotamiento se produce siempre por rotura de la lámina. Los resultados obtenidos ponen de manifiesto que refuerzos de láminas y tejidos de fibra de carbono influyen notablemente sobre las piezas, mejorando su capacidad portante y modificando su comportamiento estructural en cuanto a rigidez y ductilidadA study on the behaviour of six beams reinforced with carbon fiber laminates and fabrics was done. The validity of the two most commonly used methods of evaluating the effects of these reinforcements was analyzed. Both methods propose equilibrium equations based on forces and moments, although introducing two different suppositions: i that the steel posesses enough elasticity to avoid breakage, and ii failure is always produced by the breakage of the laminate. The results obtained demonstrate that carbon fiber laminates and fabric reinforcements have notable influence on the pieces, improving their loading capacities and modifying their structural behavior regarding stiffness and ductility

  1. Estudio microbiológico y anatomopatológico de bronquiectasias sangrantes en piezas de resección pulmonar

    Directory of Open Access Journals (Sweden)

    Alfonzo Uribe-Barreto

    2009-01-01

    Full Text Available La hemoptisis periódica o recurrente en los pacientes con bronquiectasias sangrantes constituyen un factor de alto riesgo de muerte, asimismo, existe un alto desconocimiento de la comunidad médica acerca de la existencia de otros agentes oportunistas, ajenos a la tuberculosis pulmonar, que pueden producirlas. Objetivos. Describir las características microbiológicas y anatomopatológicas de una serie de pacientes con bronquiectasias sangrantes que fueron negativos a tuberculosis, HIV y neoplasias, en estudios preliminares. Materiales y métodos. Se desarrolló una evaluación microbiológica y anatomopatológica en búsqueda de hongos, tuberculosis, gérmenes comunes y neoplasia pulmonar, sobre 24 piezas operatorias de pacientes con hemoptisis por bronquiectasias sangrantes con antecedente de tuberculosis pulmonar o de contacto con personas que padecían esa enfermedad. Resultados. El hongo Aspergillus fue hallado en 20 de los 24 pacientes estudiados. No se reportó resultados positivos en los exámenes realizados para gérmenes comunes aerobios y tuberculosis. El estudio anatomopatológico, confirmó la presencia de micetoma y Aspergillus. El tejido cicatricial invadido está altamente vascularizado con predisposición a hemorragia y a un acto operatorio de tiempo prolongado. Conclusiones. El hongo Aspergillus es el principal y único agente infeccioso presente en pacientes con bronquiectasia sangrante en esta serie.

  2. El mobiliario de “mosaico vegetal” para Isabel II. El despacho de la reina y otras piezas

    Directory of Open Access Journals (Sweden)

    Sancho Gaspar, José Luis

    2011-06-01

    Full Text Available Luxury furnishings of exceptional quality preserved in state institutions have long been considered to have been gifts of the Monarchs, and particularly of Isabel II. The authors here resolve the origin, manufacture and vicissitudes of one of these groups made for the office of the Queen in the Madrid Royal Palace, but currently located in the Supreme Court.

    Muebles de lujo y especial calidad conservados en instituciones estatales han venido siendo considerados como regalos de los monarcas, y en especial de Isabel II. Se resuelve aquí el origen, fabricación y vicisitudes de uno de estos conjuntos destinado al despacho de la reina en el Palacio Real de Madrid y localizado en el Tribunal Supremo.

  3. Formación de grafito chunky en piezas de pequeño espesor fabricadas utilizando fundición de hierro con grafito esferoidal

    Directory of Open Access Journals (Sweden)

    Asenjo, I.

    2011-10-01

    Full Text Available Chunky graphite is a degenerated graphite form which can be found in the thermal centre of ductile iron heavy section castings. Previous studies made on cubic blocks (300 and 180 mm in side manufactured using alloys with fully ferritic matrix structures show that low cooling rates, excessive post-inoculation and high silicon and/or cerium contents in the melts are the most important factors that promote this kind of defect. The enhancement of these critical factors led to obtain chunky graphite in sections lower than 50 mm. Different experimental conditions have been used in order to establish the main parameters that affect this graphite malformation. The use of cutting-edge techniques in the analysis of chemical compositions has revealed that no significant differences can be found when comparing chunky areas and well-formed spheroidal graphite areas. On the other hand, it has not been possible to establish any correlation between the oxygen contents and the scale of the defect. However, it is noteworthy that the oxygen content is related to the use of magnesium or cerium as nodulizer agent.

    El grafito chunky es una malformación detectada habitualmente en las zonas de última solidificación pertenecientes a piezas de fundición grafítica esferoidal con enfriamientos muy lentos. Estudios previos realizados sobre bloques cúbicos de 300 y 180 mm de lado y fabricados con aleaciones de matriz ferrítica, indican que los factores que promueven la formación de este defecto son: bajas velocidades de enfriamiento, excesiva post-inoculación del metal de colada y la presencia de elevados contenidos de silicio y/o cerio. La intensificación de estos factores en la fabricación de piezas con espesores más reducidos ha permitido obtener grafito chunky en secciones inferiores a 50 mm. Se han utilizado diferentes condiciones experimentales y se han determinado los factores de mayor influencia en la formación del defecto. La utilización de t

  4. Resistencia al cizallamiento de amalgama adherida utilizando dos sistemas adhesivos en dientes temporales in vitro

    OpenAIRE

    Chiappe González, Alezandra; Céspedes Porras, Jacqueline

    2006-01-01

    Objetivo general: determinar in Vitro la resistencia al cizallamiento de dos sistemas adhesivos en restauraciones de amalgama adherida en dientes temporales. Material y Método: se evaluó dos sistemas adhesivos de diferente tipo de curado: Un sistema adhesivo de curado dual (Clearfil Liner Bond 2v) y otro de autocurado (Multilink). Treinta molares libres de caries fueron divididas en dos grupos de 15 cada uno. Se incluyeron las piezas en cilindros de resina acrílica, se desgastó ca...

  5. Los modelos clásticos del Dr. Auzoux, del aula al museo

    OpenAIRE

    Gomis Blanco, Alberto; Ruiz Berdún, María Dolores

    2016-01-01

    El objetivo de este trabajo es demostrar el gran interés que suscitaron, en los docentes españoles, los modelos clásticos del médico francés Louis Auzoux, elaborados en papel maché, desde fecha muy temprana. Se ha constatado, también, la llegada a los Institutos y Universidades Españolas, en la segunda mitad del siglo XIX, de un buen nú- mero de piezas salidas de los talleres que Auzoux estableció en su localidad natal de Saint Aubin d´Ecosville en 1828. Desgraciadamente, al...

  6. La audiencia previa al juicio en el modelo procesal civil español

    OpenAIRE

    GASCÓN INCHAUSTI, Fernando; Palomo Vélez,Diego

    2007-01-01

    El trabajo analiza con detalle una de las piezas clave del nuevo proceso civil español, la audiencia previa al juicio. Se trata de una vista oral que ha de celebrarse en los juicios ordinarios una vez que las partes ya han presentado por escrito su demanda y su contestación, y que tiene una finalidad múltiple: conciliadora, depuradora de vicios procesales, delimitadora del objeto del proceso y del debate y preparatoria del acto del juicio en sí, a través de la proposición y admisión de las pr...

  7. EFICACIA DE LA PREPARACIÓN BIOMECÁNICA DE CONDUCTOS RADICULARES EN EL CRECIMIENTO MICROBIOLÓGICO EN PIEZAS DENTARIAS ANTERIORES CON NECROSIS PULPAR EN PACIENTES DE LA CLÍNICA ODONTOLÓGICA UANCV. JULIACA, PUNO. 2013

    OpenAIRE

    2015-01-01

    RESULTADOS TABLAS DE INFORMACIÓN GENERAL TABLAS QUE RESPONDEN A LOS OBJETIVOS MICROBIOLOGÍA ENDODÓNTICA VÍAS MICROBIANAS DE ACCESO TÚBULOS DENTINARIOS CAVIDAD ABIERTA MEMBRANA PERIODONTAL REQUERIMIENTOS PARA UN PATÓGENO ENDODÓNTICO POTENCIAL DE OXIDO-REDUCCIÓN ANTAGÓNICOS INTERMICROBIANOS NECROSIS PULPAR TIPOS DE NECROSIS PREPARACIÓN BIOMECÁNICA EN PIEZAS CON NECROSIS PULPAR INSTRUMENTOS CONVENCIONALES DE ACERO INOXIDABLE CARACTERÍSTICAS DE LAS LIMAS K DE ACERO INOXIDABLE PROPIEDADES FÍSICAS ...

  8. El Atlas Anatómico de la Facultad de Medicina de la Universidad de Zaragoza. La recuperación de una pieza importante del patrimonio histórico universitario

    OpenAIRE

    Moralejo Álvarez, María Remedios

    2012-01-01

    La Universidad de Zaragoza puede honrarse de poseer dos piezas excepcionales, fruto del genio de los dos aragoneses más universales: un ejemplar de la primera edición de los Caprichos de Goya con comentarios manuscritos y el Atlas de Anatomía de Cajal y sus sucesores. Este artículo informa sobre el tratamiento de estas dos obras en la Biblioteca Universitaria y se centra en el Atlas de Anatomía, restaurado. El Atlas es un enorme volumen (1.385 x 950 x 9.5 cm y unos 60 Kg de peso) con tapas...

  9. Desarrollo de sistemas ligantes para la obtención de piezas metálicas y cerámicas mediante la tecnología de moldeo por inyección de polvos

    OpenAIRE

    2008-01-01

    El Grupo de Síntesis y Procesado de Materiales de la Universidad Carlos III de Madrid tiene una experiencia dilatada en la tecnología de Moldeo por Inyección de Polvos (PIM). La ventaja fundamental de la tecnología es la fabricación de piezas de pequeño tamaño y forma complicada que no se pueden obtener mediante tecnologías convencionales de fabricación. Nuestro grupo ha desarrollado de forma satisfactoria, y en colaboración con diversas empresas, varios sistemas ligantes para la obtención de...

  10. El uso de técnicas de Simulación para la predicción de defectos en piezas fundidas. // The use of simulation techniques for the prediction of defects in casting parts.

    Directory of Open Access Journals (Sweden)

    T. Rodríguez Moliner

    2004-09-01

    Full Text Available El uso de técnicas de simulación para predecir defectos en piezas fundidas es una técnica ampliamente difundida en elmundo. Esto conlleva grandes ahorros de tiempo y recursos, además de aumentar la calidad de las piezas que se obtienen.Estas ventajas son ejemplificadas en el siguiente artículo mostrando las posibilidades del uso de este tipo de técnicas en elcampo de la tecnología de la fundición.Palabras Claves: simulación, solidificación, llenado del molde, rechupe.______________________________________________________________________________AbstractThe aim of the present paper is to show the evident advantages of using simulation techniques in foundry technologies. Theconsiderable save of time and economic resources that implies the use of this techniques has spread worldwide.As in Cuba the use is not extended to the foundries, we intend to demontrate the possibilities of the use of simulationsoftware for the development of casting technologies.Key words: simulation, solidification, mould filling, shrinkage.

  11. Optimización de los parámetros tecnológicos para la obtención de piezas de latón por pulvimetalurgia

    Directory of Open Access Journals (Sweden)

    Krivij, N.

    1995-12-01

    Full Text Available Powders of brass 60 (40 % Zn and brass 80 (20 % Zn have been produced by spraying molten metal with water at high pressure in the powder metallurgy plant belonging to the Metallurgical Research Centre (CIME in Havana. A physical-chemical and technological characterization of the powders has been carried out and the optimum parameters have been determined for the formation and sintering of details from these powders. The mechanical properties of these details can rival bronze and iron in applications such as in household electrical goods and in construction.

    Se han producido polvos de latón 60 (40 % de Zn y latón 80 (20 % de Zn mediante la atomización del metal fundido con agua a alta presión, en la planta de pulvimetalurgia del Centro de Investigaciones Metalúrgicas (CIME de La Habana. Se ha realizado la caracterización fisicoquímica y tecnológica y se han determinado los parámetros óptimos para conformar y sinterizar piezas a partir de estos polvos. Las propiedades mecánicas de estas piezas pueden competir con las de bronce y hierro, en aplicaciones para equipos electrodomésticos y en construcción.

  12. APLICACIÓN DE LAS METODOLOGÍAS ÁGILES EN EL PROCESO DE PRODUCCIÓN DE PIEZAS DE ARTE DE NUEVOS MEDIOS: BIO-LENCIA COMO CASO DE ESTUDIO

    Directory of Open Access Journals (Sweden)

    María Teresa Gutiérrez Martínez

    2011-08-01

    Full Text Available Inspirado en la idea original del artista plástico Alfredo Salomón y bajo el título de Bio-lencia, se creó un sistema en tiempo real que integra dos áreas del conocimiento: Arte y Computación. En este artículo analizamos, las características de la pieza como un producto de software y los retos que este tipo de productos presentan desde el punto de vista de la ingeniería de software. Presentamos una clasificación para el arte de medios inestables destacando sus características como productos de software y se realiza un ejercicio de producción de una pieza de este tipo utilizando metodologías ágiles de desarrollo. En particular discutimos la utilización de la Programación Extrema, la cual en el caso que aquí se presenta, permitió interactuar correctamente con el artista, quien es también el desarrollador principal. Se menciona también como las características de confiabilidad, robustez y tiempo de respuesta fueron de particular importancia para la correcta evaluación y funcionamiento del software que da vida a Bio-lencia. Finalmente como parte de las conclusiones se discuten los problemas y las lecciones que aprendimos durante el desarrollo de Bio-lencia.

  13. Leyendo el sur. A propósito del libro Cantes al Amorsillega de Ginés Liébana

    Directory of Open Access Journals (Sweden)

    Bartolomé Delgado Cerrillo

    2011-06-01

    Full Text Available A través de los poemas del libro Cantes al Amorsillega de Ginés Liébana, haremos un recorrido por las principales coplas del cante flamenco, incidiendo en la personal interpretación que nos da el autor y aportando su relación con la significación de las formas poéticas y las imágenes con que las ilustra. Este libro es valioso para ser integrado en la educación reglada como producto cultural. Y es valioso no solo como portador de contenidos antropológicos, sociológicos, coreográficos, musicales, poéticos e históricos, sino también como compendio de los estereotipos culturales que caracterizan la identidad cultural andaluza.

  14. Valoración de los principales parámetros que definen la calidad de las superficies anodizadas en piezas de aluminio para la construcción. // Evaluation of anodized surfaces main parameters that define quality of aluminum parts.

    Directory of Open Access Journals (Sweden)

    J. A. Pérez García

    2004-01-01

    Full Text Available Actualmente en la construcción de edificaciones se utiliza profusamente el aluminio en puertas, ventanas, pasamanos, etc.Con el objetivo de mejorar los parámetros que caracterizan sus cualidades estéticas y de resistencia a la corrosión, estosartículos son sometidos al proceso de anodizado. De todos los factores que intervienen en este proceso, se ha llegado aconocer que hay tres que tienen mayor relevancia en la obtención de la calidad deseada en las piezas: tratamiento previo dela superficie a anodizar, color a aplicar y espesor de la capa de recubrimiento. Este trabajo ofrece, sobre la base deexperimentos llevados a cabo, las relaciones cualitativas entre estos factores y los parámetros que caracterizan la calidaddesde el punto de vista estético (brillo, aspecto, textura y de su resistencia a la corrosión.Palabras claves: Aluminio, anodizado, calidad.__________________________________________________________________________Abstract.Aluminum articles such as windows and doors, etc are widely applied in modern building construction. In order to upgradeaesthetic and corrosion resistant properties of these articles the anodizing process is frequently used. Among all factors thatare involved in this process, there are three having high relevance in order to obtain the desired quality of the final product:previous surface treatment (before anodizing, color of the final article and anodized layers thickness. This paper offers thequalitative relationships between these factors and parameters characterizing corrosion resistance properties and aesthetics.Key words: Aluminun, anodize, quality.

  15. Principales aspectos sobre la metódica para la planificación de piezas de repuesto de las maquinas cosechadoras // Main aspects on the methodical of planning spare parts for combined harvester.

    Directory of Open Access Journals (Sweden)

    M. N. Navarro Ojeda

    2000-03-01

    Full Text Available La planificación de las piezas de repuesto de las máquinas cosechadoras constituye un elemento de vital importancia para labuena marcha de la zafra, elemento éste que aún presenta problemas de base. Basta decir, que de forma histórica, porejemplo, en la Industria Azucarera, el cálculo de las piezas de repuesto de las principales máquinas y equipos agrícolas seha hecho según datos de la experiencia; pero muchas veces estos cálculos no satisfacen el real comportamiento de losconsumos durante las reparaciones operativas y profilácticas que deben llevarse a cabo. En repetidas ocasiones ocurrenfaltantes o por el contrario sobrantes en diferentes renglones. Se describen los diferentes pasos de una metódica de cálculoque sienta sus bases en un modelo sobre desgaste y renovación de Ihle-Rößner. Su adecuación práctica permitiríaresultados muy favorables a la hora de ejecutar los ciclos de mantenimiento y reparación de las máquinas cosechadoras.Palabras claves: Piezas de repuesto, planificación, mantenimiento, cosechadoras de caña._____________________________________________________________________________AbstractThe planning of spare parts for sugar cane croppers constitutes an element of vital importance for the good performance ofthe sugar-cane crop. Such element still presents problems on its base.. For example, in the sugar cane industry, thecalculation of spare parts of the main machines and agricultural equipments has been made according to experience data.However, many times these calculation do not satisfy the real behaviour of the supplies during operative andprofilactic replacements. A very frequent fact is the lack or overplus of this spares parts in different line branches.In thiswork, the different steps of a calculation methodic based in a wear and renovation Ihle-Rößner model are described. Itspractical fitting will allow very favorable results for the maintenance and repair cycles of the combined harvesters

  16. Determinación de los tiempos de retraso en gestión y búsqueda de piezas de repuesto de las cosechadoras de arroz en el Complejo Agroindustrial Arrocero "Los Palacios"

    Directory of Open Access Journals (Sweden)

    Erwin Herrera González

    2011-01-01

    Full Text Available Los tiempos de gestión y búsqueda de piezas de repuesto de las cosechadoras de arroz durante la cosecha es un indicador determinante para minimizar el tiempo de restablecimiento de la capacidad de trabajo de las máquinas una vez ocurrida la falla; por lo que se hace necesario aumentar la eficiencia del proceso. Durante el cálculo se tienen en cuenta los factores que influyen en las pérdidas de tiempo por retraso administrativo y logístico y así proponer las medidas para eliminar o disminuir los tiempos improductivos, asegurar la capacidad de trabajo de las cosechadoras y por tanto su productividad.

  17. Fabrication and tribological properties of Al reinforced with carbon fibers

    Directory of Open Access Journals (Sweden)

    Estrems Amestoy, Manuel

    2000-10-01

    Full Text Available The present work studies the manufacturing process of Al reinforced with Carbon Fibres (CF by "Squeeze Casting", establishing the variables for obtaining an acceptable product with little Al4C3 at the interface. Friction and wear tests are performed and the necessary conditions for the formation of a tribofilm are established. The tests show an increasing resistance to abrasion due to their own wear mechanism. Certain design criteria for those components subjected to friction are recommended in order to maximise the mechanical performance of the tribological system.

    Este trabajo estudia el proceso de fabricación de composites Al reforzado con fibras de carbono mediante la técnica ''Squeeze Casting'', estableciendo las variables para obtener un producto aceptable que tenga poca cantidad de Al4C3 en la interfase. Se han realizado ensayos de fricción y desgaste y se han establecido las condiciones necesarias para la formación de la tribocapa. Se muestra la alta capacidad de resistencia a la abrasión de las piezas producidas debido a su propio mecanismo de desgaste y se recomiendan ciertos criterios de diseño para componentes mecánicos con el fin de optimizar las prestaciones mecánicas en un sistema tribológico.

  18. Comportamiento del acabado superficial de la pieza y el desgaste de la herramienta al fresar aluminio con altas velocidades de corte en fresadoras cnc convencionales. // Superficial finish behavior and tool wear in aluminium milling with high cutting spee

    OpenAIRE

    2006-01-01

    La demanda de componentes mecánicos de alta calidad y gran exactitud para sistemas de elevado desempeño estaaumentando considerablemente en los últimos años a nivel mundial. Este hecho ha provocado el desarrollo de nuevastecnologías aplicadas a los procesos de corte.El desarrollo integral de las máquinas herramientas (controles, husillos de alta velocidad) de las herramientas de corte(nuevos materiales para los substratos y capas) y de la tecnología de maquinado posibilitó la aplicación del c...

  19. Planificación del proceso de fresado de una pieza compleja utilizando una máquina herramienta virtual//Milling process planning of a complex workpiece using a virtual machine tool

    Directory of Open Access Journals (Sweden)

    Jorge‐Andrés García‐Barbosa

    2014-08-01

    Full Text Available Se diseñó y se fabricó exitosamente una pieza experimental compleja compuesta de superficies con curvatura cero, positiva y negativa. Se planificó y se ejecutó el proceso de fabricación por maquinado usando el proceso de fresado con herramientas de punta esférica en un centro de maquinado vertical equipado con un cuarto eje de rotación externo. Para la planificación, simulación y verificación del proceso se desarrolló un modelo virtual de la máquina herramienta disponible y sus accesorios en un sistema comercial de maquinado asistido por computador. Se implementó el montaje virtual del sistema de manufactura con el que se verificó y se ajustó el proceso hasta observar un buen desempeño. Se comprobaron así las ventajas de utilizar los recientes métodos virtuales ofrecidos por varios sistemas de maquinado asistido por computador para la simulación del proceso, especialmente cuando se trata de componentes complejos procesados en máquinas herramienta de más de tres ejes.Palabras claves: máquinas herramienta virtuales, planificación de procesos, maquinado de piezas complejas, simulación y verificación de procesos, maquinado multiejes.______________________________________________________________________________AbstractWe designed and successfully manufactured a complex experimental piece composed of surfaces with zero, positive and negative curvatures. We planned and executed the machining manufacturing process by using milling process with end ball nose tools on a vertical machining center equipped with a fourth external rotational axis. For planning, simulation and verification of the machiningprocess, we developed a virtual model of the machine tool and its accessories in a commercial system for computer aided machining. By mounting the virtual manufacturing system, we verified the process and adjusted it until observe a good performance. We tested and confirmed the advantages of using the recent virtual methods for

  20. MEMORIA DE UNA PIEZA DE MUSICA-TEATRO SOBRE LA BASE DE UN CUENTO RELATIVO A LA PATERNIDAD AUSENTE: HACIA UNA METODOLOGIA DE CRAECION

    OpenAIRE

    FERNANDEZ FRESARD, GALA CATALINA

    2012-01-01

    El presente proyecto consigna el trabajo de un laboratorio de investigación y experimentación dramatúrgica, musical y escénica, enfocada a la creación de un espectáculo de música-teatro destinado principalmente al grupo etario preescolar (4 a 6 años de edad) y a la realidad chilena actual. Dado que el proyecto cruza temáticas de las áreas del teatro, la música y la psicología infantil, se han explorado los campos teóricos de la narratividad y dramaturgia sobre la base de tex...

  1. Transcripciones

    OpenAIRE

    2015-01-01

    Pieza n° 1: Pasacalle Pieza n° 2: Pasacalle Pieza n° 3: Juego Pieza n° 4: Tipac tipac Pieza n° 5: Cuatro esquinas Pieza n° 6: Alto ensayo – Waychaw Pieza n° 7: Alto ensayo - Siu sao Pieza n° 8: Pampa ensayo (versión 1) (Mco B y Mco 1 son ejecutadas al final de todas las versiones de Pampa ensayo) Pieza n° 9: Pampa ensayo (versión 2) Pieza n° 10: Pampa ensayo (versión 3) Pieza n° 11 : Pampa ensayo (versión 4) Pieza n° 12: Pampa ensayo (versión 5) Pieza n° 13: Pampa ensayo (versión ...

  2. Géneros y modernidad en la escultura española de fines del siglo XIX. Una aproximación a través de seis piezas del Prado depositadas en Canarias

    Directory of Open Access Journals (Sweden)

    Carlos Reyero

    2013-11-01

    Full Text Available Se analiza un grupo deseis esculturas que pertenecen a las colecciones del Museo del Prado. Están depositadas en el Museo de Bellas Artes de Santa Cruz de Tenerife desde 1908. Estas piezas fueron expuestas en Madrid, poco después de esculpidas o modeladas por sus autores (Moratilla, Carretero, Menéndez Entrialgo, Cabrera, Ridaura y Coullaut-Valera, con motivo de las exposiciones nacionales celebradas en 1867, 1897, 1899 y 1901. A pesar de que la crítica contemporánea subrayó la importancia de los temas para valorarlas, este viejo punto de vista contribuyó a reflexionar sobre las modernas tendencias en la escultura española del siglo XIX.The object of analysis is a group of six sculptures that belongs to the Prado Museum Collections. They are deposited in the Fine Arts Museum of Santa Cruz de Tenerife from 1908. These pieces were exhibited in Madrid, soon after they were carved or modeled by their authors (Moratilla, Carretero, Menéndez Entrialgo, Cabrera, Ridaura y Coullaut-Valera, on the occasion of the national exhibitions celebrated in 1867, 1897, 1899 y 1901. In spite of contemporary criticism emphasized the importance of subjects in order to appraise them, this old point of view contributed to think over modern trends in nineteenth century spanish sculpture.

  3. Formación de capa híbrida al cementar postes metálicos y de fibra de vidrio en dientes tratados endodónticamente Hybrid layer formation using metal post and fiber post into endodontically trated canal roots

    OpenAIRE

    V. Valenzuela Aránguiz; X. Zamorano Pino; S. Wagner Hitschfeld; J.R. Tapia Silva

    2010-01-01

    Se evaluó al microscopio electrónico de barrido (MEB) la efectividad de la adhesión lograda dentro de conductos tratados utilizando dos sistemas adhesivos, uno de fotocurado (Single Bond) y otro dual (Prime & Bond NT + Self-Cure Activator) y dos sistemas de postes (fibra de vidrio y metálicos). El objetivo fue evaluar la formación de capa híbrida y tags de resina al interior de los conductos radiculares. Método: Doce piezas dentarias fueron preparadas para recibir un poste. Se dividieron en d...

  4. Evaluación de minerales alumino silicatos de Norte de Santander para fabricar piezas cerámicas de gran formato

    Directory of Open Access Journals (Sweden)

    Sandra Milena Rozo-Rincón

    2014-12-01

    Full Text Available Se dan a conocer los resultados de la influencia del feldespato al ser mezclado con arcilla del área metropolitana de Cúcuta (Norte de Santander, Colombia, en relación con las principales variables que son tenidas en cuenta a la hora de fabricar un producto cerámico tradicional de gran formato mediante técnica de conformado por extrusión. Los materiales empleados fueron arcillas provenientes de las formaciones León y Guayabo, y el feldespato del municipio de Sardinata, los cuales fueron estudiados mediante difracción de rayos (DRX y fluorescencia de rayos X (FRX. Las probetas conformadas se realizaron empleando proporciones de 100:0, 90:10 y 80:20 de arcilla-feldespato, respectivamente, y fueron sometidas a cocción a las temperaturas de 950°C-1000°C-1050°C. Se observó que la adición de feldespato mejoró de manera significativa las propiedades estudiadas para todas las arcillas empleadas en comparación con la mezcla patrón. Las muestras preparadas con arcilla Támesis presentaron el mejor desempeño.

  5. Microstructural effects of phosphorus on pressure die cast Al-12Si components

    Directory of Open Access Journals (Sweden)

    Suárez-Peña, B.

    2007-10-01

    Full Text Available The refinement of cuboidal silicon in eutectic Al-Si alloys by phosphorus additions used to manufacture pressure die cast components was studied. The results show that the addition of phosphorus in the form of AlFeP mother alloy before process degassing, leads to the best refinement of the size of the Si-cuboids phase, among several phosphorus additions analysed in the present research.

    Se ha estudiado el afino del silicio cuboidal en aleaciones eutécticas Al-Si por acción del fósforo, en piezas obtenidas mediante la técnica de fundición a presión. Tras la adición de fósforo en pruebas industriales, en las que dicho elemento se incorpora al baño con diversas composiciones, los mejores resultados se obtienen con la adición de la aleación madre AlFeP, previa al desgasificado industrial.

  6. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    Science.gov (United States)

    Martinez Mateo, Isidoro Jose

    fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  7. Pérdida de flúor en piezas dentarias permanentes expuestas a refrescos: estudio comparativo in vitro Fluor loss in permanent teeth exposed to beverages: Comparative study in vitro

    Directory of Open Access Journals (Sweden)

    P Núñez

    2006-04-01

    Full Text Available Introducción: La exposición a refrescos y zumos de frutas se encuentra en constante aumento, siendo su principal característica la elevada acidez que presentan. Con estas alteraciones del equilibrio oral, la perdida mineral de la estructura dentaria es muy frecuente. Nuestro objetivo fue identificar la cantidad de flúor perdido de una pieza dentaria y comparar el efecto de dos bebidas presentes en el mercado. Metodología: Se formaron dos grupos con 15 premolares cada uno, extraídos por indicación de ortodoncia; las piezas no presentaban patologías clínicas. El experimento consistió en la aplicación de un amortiguador de fuerza iónica para posteriormente llevarlo a una curva de calibración. Luego con un pH metro (ORION, modelo 920 A se obtuvo los datos de pH de las bebidas; luego, durante 30 minutos se sumergió en la respectiva bebida para que con el electrodo se obtuviera los resultados de flúor presente. Se realizo la prueba estadística T test para muestras independientes. Resultados: cada vez más estudios confirman el impacto de los ácidos en la cavidad oral y su papel en la erosión dentaria. En nuestro estudio se aprecio un pH de 3,1 para la bebida de naranja y 2,5 para la bebida cola. Además arrojo diferencia significativa de la pérdida de flúor según la bebida aplicada (pIntroduction: The exposure of soft drinks and fruit juices is constantly increasing and the main caracteristic of these beverages is the high acidity. This alteration of oral balance causes a more frequent loss of dental minerals. Our main objective was to identify the quantity loss of fluor of a tooth and compare this effect caused by two different kinds of soft drinks. Methodology: 30 bicuspids were put in two different groups, 15 in each, extracted by ortodontics indication The tooth did not have evidence of clinical pathology. The experiment consisted in applying an ionic buffer, and later put the results in a calibration curve. So with a p

  8. AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Desport Estelle

    2012-08-01

    Full Text Available Abstract Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig light chains (LC (most commonly of lambda isotype usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in β leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and

  9. Uso estructural de vigas DÚO y TRÍO. Vigas de madera compuestas por dos o tres piezas: una alternativa ideal para estructuras ligeras de alta exigencia estética

    Directory of Open Access Journals (Sweden)

    García Barbero, Manuel

    2007-06-01

    ía más complejo, dado que los técnicos y profesionales del sector se han de someter a normas cada vez más exigentes que pretenden garantizar la calidad final de la edificación. Paralelamente a lo mencionado existe otra evolución que repercute en todo el espectro de materiales y sistemas constructivos, también en la madera. Convertir la madera en un material con características estandarizadas es una tarea compleja pero llena de soluciones inteligentes. El concepto DÚO y TRÍO es una muestra más de ingeniería de materiales que surge de la adecuada realización de análisis de las características propias del material y una aplicación técnica consecuente de los conocimientos del mismo para generar un nuevo producto industrial de alto valor añadido.Este concepto concreto consiste en la unión, por medio de encolado, de piezas de madera de formatos superiores a las láminas corrientes de vigas laminadas. Esta unión se realiza de forma tal que dichas piezas queden con la superficie de encolado en posición vertical, de tal modo que las caras con los anillos de crecimiento más exteriores queden en el interior de la viga y las caras que se situaban más interiormente en el tronco original, queden vistas hacia fuera. Las ventajas son múltiples: desde el punto de vista visual los cortes más interiores presentan menos nudos y son éstos los que aparecen en la cara exterior en el sistema DÚO. Desde el punto de vista de la geometría de las vigas, las deformaciones de las mismas son menores y el fendado lateral casi inexistente. Desde el punto de vista de las propiedades mecánicas, se consigue una optimización en el uso de la madera de costeros del tronco originario, de una mayor resistencia, uniéndose para conformar piezas de mayor escuadría.

  10. Análisis a fatiga de un bulón en el interior de un pistón debido al movimiento del cigüeñal

    OpenAIRE

    Pérez García, Jairo

    2016-01-01

    El objetivo del presente trabajo de fin de grado es predecir la vida a fa-tiga del bulón en el interior de un pistón debido a las fuerzas producidas por el movimiento rotatorio del cigüeñal y simulando el conjunto de componentes como un mecanismo biela-manivela. Para la modelización virtual de las piezas se procederá a crearlas me-diante el software de dimensionado den 3 Autodesk Inventor. El propósito fi-nal será evaluar el bulón con el programa de análisis por elementos finitos Si-mulatio...

  11. El Atlas Anatómico de la Facultad de Medicina de la Universidad de Zaragoza. La recuperación de una pieza importante del patrimonio histórico universitario.

    Directory of Open Access Journals (Sweden)

    Moralejo Álvarez, María Remedios

    2012-01-01

    Full Text Available La Universidad de Zaragoza puede honrarse de poseer dos piezas excepcionales, fruto del genio de los dos aragoneses más universales: un ejemplar de la primera edición de los Caprichos de Goya con comentarios manuscritos y el Atlas de Anatomía de Cajal y sus sucesores. Este artículo informa sobre el tratamiento de estas dos obras en la Biblioteca Universitaria y se centra en el Atlas de Anatomía, restaurado. El Atlas es un enorme volumen (1.385 x 950 x 9.5 cm y unos 60 Kg de peso con tapas de madera forradas de arpillera, lomos y cantoneras de piel y dos cierres metálicos, con 34 hojas que contienen 49 láminas en color, las doce primeras tradicionalmente atribuidas a Cajal entre 1877 y 1883 y las restantes de otros autores, contemporáneos o posteriores. El Atlas fue, durante años, intensamente utilizado en las clases como material didáctico. Cuando dejó de utilizarse, a los daños producidos por el uso se sumaron los de la humedad. El Atlas de Anatomía, restaurado, y enriquecido con seis láminas descubiertas en el proceso de restauración, se incorporó a la colección histórica de la biblioteca Universitaria.The University of Zaragoza can be honoured of owning two exceptional pieces, fruit of the genius of the two most universal Aragonese men: a copy of the first edition of Goya's Caprichos with manuscript commentaries, and the Atlas of Anatomy of Cajal and his successors. This article reports on dealing with both works in University Library and focuses on the Atlas of Anatomy restored. The Atlas is an enormous volume (1.385 x 950 x 9.5 cm. and nearly 60 kg in weight with wooden covers lined with burlap, leather spine and cornerpieces and two metal clasps, with 34 leaves containing 49 pictures in colour, the first twelve are traditionally attributed to Cajal, betwen1877 and 1883; the following pictures from other authors, contemporary and later than Cajal. The Atlas was intensively used in the classroom for many years as didactic

  12. Mouthparts and associated sensilla of a South American moth, Synempora andesae (Lepidoptera: Neopseustidae Piezas bucales y sensilios asociados de Synempora andesae, una polilla de Sudamérica (Lepidoptera: Neopseustidae

    Directory of Open Access Journals (Sweden)

    Michel J. Faucheux

    2008-06-01

    Full Text Available The mouthparts of Synempora andesae Davis & Nielsen were studied by means of scanning electron microscope. The existence of gustative uniporous sensilla styloconica is demonstrated for the second time on the proboscis of Neopseustidae. It is with this family, and not at a later stage within the Incurvaroidea, that these sensilla appear during the evolution of Lepidoptera. Contrary to common belief, the labial-palp-pit organ, or organ of vom Rath, is present at the distal extremity of the labial palpi of S. andesae. It is made up of a dozen of grooved multiporous sensilla coeloconica whose function is carbon dioxide sensitive. Thus, its presumed absence can no longer be considered as an autapomorphy of Neopseustidae. S. andesae possesses other original characteristics: both short and long bifurcate aporous sensilla chaetica on the labrum, numerous sensilla campaniformia on the first segment of labial palpi, as well as those previously described: the double-tube configuration of the proboscis and the composite and polymorphic multiporous sensilla basiconica on the antennae. Other cephalic sensilla are also described: aporous bifurcate sensilla chaetica on the clypeus, aporous sensilla campaniformia above the mandibles, and on the chaetosemata.Las piezas bucales de Synempora andesae Davis & Nielsen fueron estudiadas con un microscopio electrónico de barrido. Se demuestra, por segunda vez, la existencia de sensilios estilocónicos gustativos uniporosos en la proboscis de Neopseustidae. Es en esta familia, y no en un estadio posterior dentro de Incurvaroidea, que aparecen estos sensilios durante la evolución de Lepidoptera. Contrario a lo que se cree, el órgano sensitivo labial u órgano de Von Rath, se encuentra en la extremidad distal del palpo labial de S. andesae. Está conformado por una docena de sensilios celocónicos multiporosos estriados, cuya función es percibir el dióxido de carbono. Por lo tanto, su supuesta ausencia ya no puede

  13. Las piezas embrujadas : El ajedrez como rito

    Directory of Open Access Journals (Sweden)

    Héctor Rojas Herazo

    1968-10-01

    Full Text Available El ajedrez, a pesar de lo que parece, no tiene nada de juego. Es, por el contrario, una azarosa trabazón de lógica y de magia, de tensión perceptiva, de asombro. Quienes lo practican saben que están ejerciendo un aspecto, tal vez el más complicado, de la filosofía de la lucha. Y saben que sus dos grandes enemigos son el espacio y el tiempo.

  14. SACANDO PIEZAS [Material gráfico

    OpenAIRE

    1989-01-01

    EL RAKÚ ES UNA TÉCNICA TRADICIONAL ORIENTAL DE ELABORACIÓN DE CERÁMICA UTILITARIA FOTOGRAFÍA DE MARÍA JESÚS HERNÁNDEZ Y EDUARDO RAMÍREZ MÉNDEZ, HACIENDO RAKÚ, EN EL TALLER DE TEMISAS. Copia digital. Madrid: Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2015

  15. Innovación y ruptura en la métrica de la poesía en al-Maqāmāt al-Luzūmiyya de al-Saraqusṭī (s. VI/XII

    Directory of Open Access Journals (Sweden)

    Ferrando, Ignacio

    2016-06-01

    Full Text Available Al-Maqāmāt al-Luzūmiyya, a collection of 50 picaresque-like stories couched in rhymed prose by Abū l-Ṭāhir al-Saraqusṭī in al-Andalus in the VI/XIIth century, were considered by Western scholars, up until the eighties of XXth century, as highly rhetorical pieces with a negligible and irrelevant content. However, some contemporary scholars argued that they contain some degree of social and political criticism, as they constitute a fictional domain in which subversion and irony play a fundamental role. In this paper, we cast some light on the particular use of metrical patterns in Al-Maqāmāt al-Luzūmiyya, which should be considered another subversion field: a poetical rhythm that avoids the most usual Arabic metrical patterns, contributing to provide the maqāma a flavor of the countergenre.Al-Maqāmāt al-Luzūmiyya, la colección de 50 relatos de corte picaresco escritos en una exigente prosa rimada por Abū l-Ṭāhir al-Saraqusṭī en al-Andalus en el siglo VI/XII, han sido consideradas por los críticos occidentales como piezas de alta retórica y de virtuosismo lingüístico en las que el contenido es prácticamente irrelevante. Sin embargo, a partir de los años 80 del siglo pasado, algunos investigadores han tratado de incidir en el hecho de que esta obra contiene cierto grado de crítica social y política, puesto que constituye un espacio ficticio en el que la subversión y la ironía desempeñan un papel fundamental. En este trabajo vamos a tratar de arrojar luz sobre el uso particular de los esquemas métricos por parte de al-Saraqusṭī, tratando de mostrar que los metros constituyen otro más de los ámbitos de subversión tan caros al autor. De hecho, el uso de ritmos “invertidos” o contrarios a los más habituales de la poesía clásica contribuye a darle a la maqāma ese aire de anti género que la puebla.

  16. Botella al mar para el dios de las palabras. Reflexiones de García Márquez sobre gramática y ortografía

    Directory of Open Access Journals (Sweden)

    Mar Jiménez Mañas

    2012-12-01

    Full Text Available La apertura del Congreso Internacional de la Lengua Española de Zacatecas, que estuvo a cargo de Gabriel García Márquez bajo el título “Botella al mar para el dios de las palabras” evidenció que no todos los hispanistas tienen una visión uniforme sobre la situación actual del español, su ortografía y su gramática. El escritor refleja una corriente de opinión sobre simplificación ortográfica y gramaticaliniciada varios siglos antes (desde Nebrija, Correas, Bello y más adelante con las propuestas de Juan Ramón Jiménez que tiene en esta ocasión una contestación contundente por parte de otros intelectuales hispanoparlantes. En el presente artículo analizamos la polémica aportando los puntos de vista más relevantes sobre la cuestión para concluir que una ortografía fonémica como la nuestra sólo se sustenta con el pilar de una ortografía históricamente coherente.

  17. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    He has described at length the various methods to which the prisoners were subjected, including sleep depravation, nudity and the use of electrodes...suspects of the Riyadh bombing acknowledge their involvement on television , he was under the impression that they too had been subjugated to this... sleeping , al-Libi, al-Zawi and `Abd al-Karim managed to escape by jumping from the six-meter-tall wall of al-Ruways.38 Their breakout led to a

  18. Risks related to exposure to radon Riesgos vinculados a la exposición al radón

    Directory of Open Access Journals (Sweden)

    Juan Miguel Barros Dios

    2010-12-01

    Full Text Available They discuss the different scientific evidence that radon and its short half-life descendants are responsible for the appearance of a considerable number of lung cancers among the exposed population in homes and public buildings (occupational exposure. It also draws a small glimpse at the road traveled by this knowledge and acceptance difficult administrations in many countries and, in particular, of Spain, as well as the various investigations that the team do Galego Radon and Radon Laboratory from Galicia, the area of Public Health, University of Santiago de Compostela (USC, are contributing to scientific knowledge. Finally, they appreciate the few legislative initiatives on the problem in Spain.Se comentan las diferentes evidencias científicas de que el radón y sus descendientes de vida media corta son responsables de la aparición de un número no desdeñable de cánceres de pulmón entre la población expuesta en domicilios y edificios públicos (exposición laboral. Asimismo, se traza una pequeña aproximación al camino recorrido por este conocimiento y su difícil aceptación por parte de las diferentes Administraciones de numerosos países y, en concreto, de España, así como las diversas investigaciones que el Grupo Galego do Radon y el Laboratorio de Radón de Galicia, del Área de Salud Pública, de la Universidad de Santiago de Compostela, llevan aportando a ese conocimiento científico. Por último, se valoran las escasas iniciativas legislativas sobre el problema en España.

  19. /Cu-Al System

    Science.gov (United States)

    Kish, Orel; Froumin, Natalya; Aizenshtein, Michael; Frage, Nachum

    2014-05-01

    Wettability and interfacial interaction of the Ta2O5/Cu-Al system were studied. Pure Cu does not wet the Ta2O5 substrate, and improved spreading is achieved when relatively a high fraction of the active element (~40 at.% Al) was added. The Al2O3 and AlTaO4 phases were observed at the Ta2O5/Cu-Al interface. A thermodynamic evaluation allowed us to suggest that the lack of wetting bellow 40 at.% Al is due to the presence of a native oxide, which covers the drop. The conditions of the native oxide decomposition and the formation of the volatile Al2O suboxide strongly depend on the vacuum level during sessile drop experiments and the composition of the Cu-Al alloy. In our case, Al contents greater than 40% provides thermodynamic conditions for the formation of Al2O (as a result of Al reaction with Al2O3) and the drop spreading. It was suggested that the final contact angle in the Ta2O5/Cu-Al system (50°) is determined by Ta adsorption on the newly formed alumina interlayer.

  20. Difuminaciones: de lo contemporáneo al Jazz

    OpenAIRE

    Galvis Parra, Juan Gabriel

    2015-01-01

    Difuminaciones desarrolla un trabajo interdisciplinar que involucra la música con una puesta en escena de luces, video y sonido. El concierto combina e integra de manera orgánica la improvisación libre con dos piezas importantes en el repertorio contemporáneo para percusión y varios temas de Jazz.

  1. Aussprache als motorische Fertigkeit

    DEFF Research Database (Denmark)

    Bonner, Maria

    2013-01-01

    Authentische Aussprache gilt im Fremdsprachenunterricht als schwer erreichbares Ziel, fremdsprachlicher Akzent wird als nahezu unvermeidbar gesehen. Weder die Hypothese einer kritischen Periode für den Erwerb einer authentischen Aussprache noch das Konzept der Fossilierung im Sprachlernprozess...

  2. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    ... ALS Neurons' broken machinery piles up in ALS Esclerosis Lateral Amiotrófica Dormant viral genes may awaken to ... Dementia Information Page Multifocal Motor Neuropathy Information Page Multiple Sclerosis Information Page Muscular Dystrophy Information Page Myasthenia ...

  3. Construcción de modelos computacionales para el análisis de esfuerzos mecánicos de piezas óseas utilizando imágenes de TC: aplicación a la articulación gleno-humeral Construction of computational models for the stress analysis of the bones using CT imaging: application in the gleno-humeral joint

    OpenAIRE

    Adrián Cisilino; Diego D'Amico; Federico Buroni; Pablo Commisso; Mario Sammartino; Carlos Capiel

    2008-01-01

    Se presenta en este trabajo una metodología para el procesamiento de imágenes de estudios de TC para la construcción de modelos computacionales de piezas óseas. Los modelos computacionales son utilizados para el análisis de esfuerzos utilizando el Método de los Elementos Finitos. Las constantes elásticas del tejido óseo son calculadas a partir de los datos de densidad de las TC. La metodología propuesta es aplicada en la construcción de un modelo para el análisis de la articulación gleno-hume...

  4. Aceros al molibdeno sinterizados con gradiente funcional

    OpenAIRE

    2014-01-01

    Las propiedades que se solicitan a las piezas y productos exigen, la mayoría de las veces, una combinación de materiales que respondan a requerimientos específicos en función de su posición. La fabricación de materiales compuestos y materiales con gradiente funcional proporciona grandes posibilidades de respuesta a las necesidades demandas, tanto de satisfacción de requerimientos como de reducción de materias primas necesarias. En este sentido, satisfacer las propiedades demandadas, de manera...

  5. Del Ipse existencial al Ipse narrativo. Fronteras y pasajes entre la fenomenología ontológica de Sartre y la fenomenología hermenéutica de Ricoeur

    Directory of Open Access Journals (Sweden)

    Francisco Samuel Naishtat

    2007-11-01

    Full Text Available En El Ser y la nada Sartre retomó la noción de Ipseidad del vocabulario de Sein und Zeit, y la desplegó como una pieza central para deslindar el para-sí, vinculado al circuito de la conciencia reflexiva y la libertad, del en-sí, como lo inerte, lo dado, la existencia de hecho. Ahora bien, Ricoeur reconsidera la categoría de Ipse en Sí mismo como otro. Pero aquí su relación con Sartre es interesante en dos direcciones: a permite clarificar su diferencia con el desgarramiento del Ipse sartriano; b permite ver allí el papel diferente que ambos autores dan a la noción de otredad.

  6. Volver al desarrollo

    Directory of Open Access Journals (Sweden)

    Jaime Ornelas Delgado

    2012-01-01

    Full Text Available El desarrollo, categoría empleada para expresar el crecimiento económico, surge durante la "guerra fría" y si bien fue propuesta por teóricos metropolitanos, se asumió en Latinoamérica como parte de los instrumentos disponibles para lograr el crecimiento y alternativa al socialismo. El desarrollo mantuvo su vigencia entre 1945 y 1975, cuando al advenimiento del neoliberalismo fue paulatinamente retirado de la agenda de las preocupaciones nacionales e internacionales. Al iniciarse el siglo xxi, el fracaso del mercado autorregulado trajo de nueva cuenta al debate los problemas del desarrollo, lo que obliga a revisarlo críticamente, tanto como al concepto mismo para mostrar su carácter colonial, si se quiere construir caminos ajenos al neoliberal y superar los problemas que han hecho de Latinoamérica una de las regiones más desiguales del mundo.

  7. Alles is al uitgevonden

    NARCIS (Netherlands)

    J.G.M. van Marrewijk (Charles)

    1996-01-01

    textabstractDe voordelen van vrijhandel zijn zeer beperkt, al-thans als we de empirische schattingen van vooraanstaande economen en internationale organisaties mogen geloven. Zo worden de voordelen van liberalisatie voor de Europese Unie geraamd op ongeveer 0,5% van het bnp 1. De door het IMF gescha

  8. Gezondheid als marketinginstrument

    NARCIS (Netherlands)

    Vijver, van de L.P.L.; Berg, van den I.

    2008-01-01

    Is biologisch voedsel beter dan gangbaar? Hoe hard zijn de bewijzen daarvoor? En hoe sterk moet het bewijs zijn voordat je het als claim op een product mag zetten? In dit Biokennis bericht een overzicht van de wetenschappelijke conclusies en de mogelijkheden om biologisch te promoten als beter, neer

  9. Initial Symptoms of ALS

    Science.gov (United States)

    ... Research In Your Community Advocate Get Involved Donate Symptoms and Diagnosis En español Symptoms The initial symptoms of ALS can be quite ... the eyes and bladder are generally not affected. Diagnosis ALS is a difficult disease to diagnose. There ...

  10. Predicción del desgaste del flanco de la herramienta de corte durante el torneado en seco de alta velocidad para piezas de acero AISI 316L en la industria minera

    Directory of Open Access Journals (Sweden)

    Yusimit K. Zamora-Hernández

    2015-07-01

    Full Text Available Se realizó un estudio experimental sobre la influencia de los parámetros de corte en el torneado del acero inoxidable AISI 316L con insertos recubiertos de TiCN, Al2O3, TiN. Un microscopio electrónico de barrido fue utilizado para medir y analizar el desgaste de las herramientas de corte. Los resultados fueron comparados utilizando el análisis de varianza y el análisis de regresión múltiple para describir la relación entre el desgaste del flanco de las herramientas de corte, el tiempo de maquinado y el avance de corte, obteniéndose las ecuaciones de los modelos ajustados. La investigación demostró el efecto significativo del avance y del tiempo de maquinado en el desgaste del flanco. El inserto de tres capas no sobrepasó el criterio de fin de vida del desgaste, mientras que el inserto de una capa sufrió un desgaste elevado para la mayor velocidad de corte. El desgaste del flanco tuvo mejor comportamiento para el avance de 0,08 mm/rev en todas las velocidades empleadas en este estudio. Los errores medios absolutos no superaron el 15 %.

  11. Volver al desarrollo

    OpenAIRE

    Jaime Ornelas Delgado

    2012-01-01

    El desarrollo, categoría empleada para expresar el crecimiento económico, surge durante la "guerra fría" y si bien fue propuesta por teóricos metropolitanos, se asumió en Latinoamérica como parte de los instrumentos disponibles para lograr el crecimiento y alternativa al socialismo. El desarrollo mantuvo su vigencia entre 1945 y 1975, cuando al advenimiento del neoliberalismo fue paulatinamente retirado de la agenda de las preocupaciones nacionales e internacionales. Al iniciarse el siglo xxi...

  12. Tussentijds Toetsen als Leerstrategie

    NARCIS (Netherlands)

    Dirkx, Kim; Kester, Liesbeth; Kirschner, Paul A.

    2013-01-01

    Dirkx, K. J. H., Kester, L., & Kirschner, P. A. (2013, April). Tussentijds toetsen als Leerstrategie [Testing as Learning Strategy]. Presentation at the Miniconference on Assessment from the Mastersprogram Educational Sciences, Heerlen, The Netherlands.

  13. Analyzing Al Qaedaism

    Institute of Scientific and Technical Information of China (English)

    Yuan Hua

    2008-01-01

    Three major events are responsible for the rampancy today of Al Qaedaism, the doctrine of Al Qaeda, an Islam extremist organization. They are: the Anti-Soviet Afghanistan War for the birth of the group; the September 11 terrorist attacks for the spread of its extremist demagogy and the war on terror for its branches networking into alliances worldwide.Al Qaedaism aims at driving away Western forces on the Moslem lands, overthrowing local Pro-West regimes, destroying Israel and setting up a Caliphate empire. Its rampancy has resulted from a combination of diverse factors at work under specific historical conditions rather an inevitable outcome of the growth of the Islam religion.As an ideological weapon for launching Jihad to oust Western influence and topple local regimes, Al Qaedaism reflects an extremist portrayal of modern Islam society, politics, economy and culture.

  14. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... to speak and write. Hawking, who has a wife and three children, once said, "The prospect of ... and arm movement. With patience, the families of patients with ALS can learn to communicate effectively with ...

  15. Sociale media als leermiddel

    NARCIS (Netherlands)

    Rubens, Wilfred

    2012-01-01

    Rubens, W. (2012, 5 juni). Sociale media als leermiddel. Presentatie over het gebruik van sociale media binnen het onderwijs, verzorgd tijdens een ouderraadbijeenkomst van de Katholieke Scholengemeenschap Etten-Leur, Etten-Leur, Nederland.

  16. Amyotrophic lateral sclerosis (ALS)

    Science.gov (United States)

    Lou Gehrig disease; ALS; Upper and lower motor neuron disease; Motor neuron disease ... 98. Shaw PJ. Amyotrophic lateral sclerosis and other motor neuron diseases. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  17. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  18. Contribuciones al desarrollo de la investigación en enfermería: retos y perspectivas

    Directory of Open Access Journals (Sweden)

    Myriam Durán Parra

    2012-12-01

    Full Text Available Desde la etimología del término “investigación” la palabra proviene del latín in (en y vestigare (hallar, inquirir, indagar, seguir vestigios. De ahí el uso más elemental del término en el sentido de “averiguar o describir alguna cosa”. Desde el momento en que el hombre se enfrentó a problemas y frente a ellos empezó a interrogarse sobre el porqué, como y para que, con esta indagación sobre las cosas, de una manera embrionaria, comenzó lo que hoy llamamos investigación. Con el transcurso del tiempo el ser humano ha hecho un esfuerzo importante por sobrevivir y la mejor forma de lograrlo ha sido experimentando aportando al desarrollo del conocimiento científico.Donaldson y Bottorff (1978 expresan frente a la investigación en enfermería que “es la fuente de desarrollo de conocimiento que le da la característica de disciplina, que ha de estar presente tanto en la práctica clínica como en el desarrollo de la administración y la educación, que ha de dar respuesta a las necesidades sociales que están relacionadas con procesos de salud-enfermedad, condiciones y calidad de vida de las personas, familias y comunidades, en todos los grupos etarios” (1. Por su parte Borrero-Cabal (1994, afirma que “la disciplina conlleva al sentido de rigor, de dedicación, de entrenamiento y ejercicio de los hábitos científicos de la persona para elaborar, transmitir y aprender una ciencia” (2. En enfermería esto se traduce que para poder llevar el cuidado a los pacientes de una manera técnica, científica , analítica, debe tener unas bases como la dedicación, el amor por la profesión y el gusto por la investigación reconociendo que la enfermería avanza y se fortalece a medida que crece científicamente, mientras conoce la cultura, la riqueza de la naturaleza, forma parte del país y sobre todo del mundo como una profesión que demuestra su interés en la búsqueda de su propia identidad. 

  19. Trauer als Biografiegenerator

    OpenAIRE

    Winkel, Heidemarie

    2008-01-01

    Der Tod eines Alter Ego erweist sich für Trauernde als gravierende Kontingenzerfahrung. Sie vermag das individuelle Selbstverständnis in umfassender Weise zu erschüttern, wobei sich Trauer als Schmerz von unvergleichlicher Intensität und Tiefe konstituiert. Die emotionale Erfahrung wird hierbei – nach Maßgabe psychologischer und therapeutischer Vorstellungen – zum Ausgangspunkt und zum Maßstab individueller Selbstvergewisserung. Diese Auffassung von Trauer korrespondiert mit einer allgemeinen...

  20. Der Preis als Kaufbarriere?

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    2012-01-01

    Die Preispolitik hat eine herausragende Stellung im Marketing. Der Preis eines Produktes ist für Verbraucher ein direkter Kostenfaktor und für Unternehmen die Stellgröße im Mar-ketingmix, die den Umsatz am stärksten beeinflusst (vgl. Nieschlag et al. 2002). Wenn die Akzeptanz und der regelmäßige...... Verzehr gesunder Lebensmittel erhöht werden soll, ist es sowohl für die Verbraucherpolitik als auch für Lebensmittelproduzenten wichtig, den Ein-fluss des Preises auf die Kaufentscheidung zu verstehen. Aus Verbrauchersicht ist der Preis neben dem Geschmack die wichtigste Produkteigen-schaft beim Kauf von...... Lebensmitteln (vgl. Brunsø/Grunert 1998) und stellt eine Kaufbarrie-re für Lebensmittel mit gesundheitsfördernden Eigenschaften dar. Studien in den USA (vgl. Cassady et al. 2007), Frankreich (vgl. Drewnowski et al. 2004; Andrieu et al. 2005) und Deutschland (vgl. Karg et al. 2008) kommen übereinstimmend zu dem...

  1. Leakage current behaviors of Al/ZrO2/Al and Al/YSZ/Al devices

    Science.gov (United States)

    Yeh, Tsung-Her; Lin, Ruei-De; Cherng, Bo-Ruei; Cherng, Jyh-Shiarn

    2015-01-01

    The leakage current behaviors of Al/ZrO2/Al and Al/yttria stabilized zirconia (YSZ)/Al devices are investigated for resistive random access memory (RRAM) applications. A silicon oxide layer (450 nm) is first formed on a Si wafer by thermal oxidation. Onto it an Al bottom electrode (270 nm), a ZrO2 or YSZ nano-film (75 nm), and an Al top electrode (270 nm) are sequentially deposited by sputtering. These RRAM devices exhibit ohmic behaviors in the low-field region, while Schottky and Poole-Frenkel emissions take over in the high-field regions. Both the Schottky and trap barrier levels are decreased when monoclinic ZrO2 is replaced by cubic YSZ in the metal/oxide/metal structure. This is attributed not only to the higher symmetry crystal structure and lower binding energy of YSZ, but also to the formation of more oxygen vacancies and their re-distribution associated with yttria doping.

  2. Evaluación de la tasa de consumo de oxígeno de Colossoma macropomum en relación al peso corporal y temperatura del agua

    Directory of Open Access Journals (Sweden)

    Dennis Tomalá

    2014-11-01

    Full Text Available Colossoma macropomum es una especie de la región amazónica perteneciente a la familia Characidae, la de mayor diversidad de peces de agua dulce. A nivel de laboratorio, se determinó la tasa de consumo de oxígeno (CO en metabolismo de rutina de C. macropomum a diferentes pesos corporales: 40, 60, 90, 140 y 250 g (expresados por unidad de masa corporal y temperatura del agua de 21, 26 y 31°C. El experimento se diseñó completamente al azar en arreglo factorial (5x3x3, utilizando un respirómetro de 20 L y una bomba de recirculación de agua. Las mediciones del CO fueron realizadas cada 5 min mediante el uso de un oxímetro digital. Los resultados indican que el CO mantiene relación directa con la temperatura del agua e inversa con el peso corporal de los organismos (P < 0,05. Las regresiones entre las variables independientes y el CO se ajustaron a ecuaciones potenciales: CO = 2844,9 P-0,734, CO = 2555,9 P-0,624 y CO = 1945,4 P-0,507 a 21, 26 y 31°C respectivamente; donde P se expresa en kg, obteniéndose altos coeficientes de correlación y determinación. La ecuación resultante del análisis multivariado de regresión lineal múltiple fue: CO = 4,839 - (0,708* P + (9,106* T. Los resultados ofrecen información para estimar la capacidad de un ambiente acuícola en base a la demanda de oxígeno de C. macropomum, aportando al desarrollo de una acuicultura con mayor sustento técnico.

  3. Cuidando al adulto y al anciano

    Directory of Open Access Journals (Sweden)

    Alba Lucero López Díaz

    2003-01-01

    Full Text Available El propósito del artículo es describir, desde el ámbito universitario, la experiencia en la aplicación de la Teoría del Déficit de Autocuidado (TDAC con la población adulta y anciana. Se explican los procesos y resultados desde la preparación docente, la conformación de la asignatura, hasta el desarrollo de la experiencia práctica en el ámbito hospitalario y de la vida cotidiana. La experiencia muestra la adecuación de la TDAC para abordar el cuidado de esta población y la necesidad de desarrollar otros estudios al respecto.

  4. Fortschritt als Fortschrittsdiskurs

    Directory of Open Access Journals (Sweden)

    Rainer Schmid-Zartner

    2014-12-01

    Full Text Available Zur Erzielung gesellschaftlichen Fortschritts in demokratisch verfassten Gesellschaften soll die Möglichkeit am Fortschrittsdiskurs teilnehmen zu können für alle Mitglieder der Gesellschaft als selbstverständliche Prämisse gelten. Fortschritt wird also als Bewusstseinsbildung dem Fortschritt selbst gegenüber und als Entscheidungs- und Handlungsfähigkeit auf individueller und gesellschaftlicher Ebene definiert. Dies setzt entsprechende Maßnahmen zur Befähigung dazu voraus, die alle Mitglieder der Gesellschaft erfassen. Dabei ist der Bildungsbereich angesprochen, insbesondere der Schulunterricht. Neben dem in der aktuellen blidungspolitischen Debatte forcierten Fokus auf den Aspekt der Kompetenzorientierung, der hier nicht infrage gestellt wird, ist als notwendige Ergänzung ein reflexionsorientierter Schulunterricht in allen Bildungsfächern einzufordern und umzusetzen. Im Weiteren beschreibt der Text den Weg von der Brauchbarkeit zur Bedeutsamkeit von schulischem Wissen durch Relevanzreflexionsprovokationen im Schulunterricht, um Sinn und Bedeutung der vermittelten Bildungsinhalte zu verhandeln. Am Beispiel von Mathematik als Bildungsfach wird der Inhalt von reflexionsorientertem Unterricht verdeutlicht. Darüber hinaus beschreibt der Text eine Reihe von konkreten Fallbeispielen aus der aktuell versuchsweise durchgeführten Unterrichtspraxis in Mathematik.

  5. Modification of residual stress in Al-[AlBO]w/Al compound plate

    Institute of Scientific and Technical Information of China (English)

    姜传海; 吴建生; 王德尊

    2001-01-01

    The application of compound parts of Al-[AlBO]w/Al not only reduces the cost of the parts but also improves its properties. However, there is a large thermal residual stress between Al and [AlBO]w/Al, and it is harmful for practical application. From the theoretical analyses and experimental results, it was found that by the compressive pre-plastic deformation perpendicular to the interface between Al and [AlBO]w/Al, the interlayer residual stress of compound parts can be reduced, while the mechanical properties of compound parts can be improved.

  6. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-03-01

    Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.This article examines different metaphorical uses of the term pornography and the resulting implications. While the existence of pornography for the feminist anti-porno movement serves as factor in the continuing discrimination of women in western societies, conservative powers on the right use the allegation of pornography as a justification for censorship of those identities and sexual practices deemed deviant.

  7. Altern als Widerstand

    Directory of Open Access Journals (Sweden)

    Roberta Maierhofer

    2005-07-01

    Full Text Available Gullettes kulturwissenschaftliche Untersuchung Aged by Culture ist wie bereits ihre zwei vorangehenden Werke, die sich mit Altern beschäftigen – Safe at Last in the Middle Years: The Invention of the Midlife Progress Novel (1988 und Declining to Decline. Cultural Combat and the Politics of the Middle (1997 –, von großem persönlichen Engagement und durch ein politisches Anliegen motiviert. Sowohl die Dringlichkeit als auch der Widerstand, den Gullette, die sich als „age critic“ definiert, als moralische und politische Notwendigkeit postuliert, werden in der Zweiteilung der Abhandlung angesprochen: „Cultural Urgencies“ und „Theorizing Age Resistantly“. Während Gullette den Begriff „aged by culture“ bereits in Declining to Decline einführt, stellt sie ihn nun in den Mittelpunkt ihrer Untersuchung. Das Buch ist einerseits einer gesellschaftspolitischen Analyse der USA gewidmet, andererseits wird eine Theorie des Widerstands gegenüber Altersdiskriminierung entwickelt.

  8. Un puñal-reliquia vacceo hallado en Pintia (Padilla de Duero, Valladolid

    Directory of Open Access Journals (Sweden)

    Sanz Mínguez, Carlos

    2008-12-01

    Full Text Available During excavation, the splendid scabbard of a Monte Bernorio dagger, made of iron and decorated with silver, was found carefully placed near the base of a clay seat inside a house in the city of Las Quintanas, in Pintia. Although the typological characteristics of the dagger date it to the 4th Century B.C., the dating of the house to the 1st Century A.D. suggests we are in the presence of a true relic, inherited through generations until its definitive interment at a time when the Vaccaean culture was undergoing a process of ‘dilution,’ being integrated in the effective Romanization of the area of the River Duero basin.

    Una espléndida vaina de hierro damasquinada en plata, correspondiente al modelo de puñal Monte Bernorio, cuyas características tipológicas remontan la pieza al siglo IV a.C., apareció, en proceso de excavación, cuidadosamente depositada junto a la base del banco de tapial de una vivienda de la ciudad de Las Quintanas, de Pintia. La casa se data, sin embargo en el siglo I d.C. En consecuencia, nos hallamos ante una verdadera reliquia que pasó de mano en mano a lo largo de generaciones, hasta su definitiva amortización en un momento en el que la cultura vaccea se diluía o, si se prefiere, se integraba en la romanización efectiva de este territorio central de la Cuenca del Duero.

  9. Carta al Editor

    Directory of Open Access Journals (Sweden)

    José Andrés Burgos Zuleta

    2010-06-01

    Full Text Available La medicina al basarse generalmente en la clínica, correlacionaexámenes complementarios y organiza un diagnóstico y tratamiento, es una disciplina donde es imprescindible saber recolectar, analizar, interpretar y concretar una respuesta adecuada, es así que la información que se recibe es esencial para el desempeño médico.La certeza es una realidad que se da en algunas situaciones y enotras las probabilidades establecen conclusiones. Lo normal muchas veces se define sobre la base de criterios estadísticos, basados en riesgos poblacionales que no necesariamente se aplican al caso boliviano.

  10. Realidad, sueño y utopía en La isla desierta. Un acercamiento al mundo teatral de Roberto Arlt

    Directory of Open Access Journals (Sweden)

    Camacho Delgado, José Manuel

    2001-12-01

    Full Text Available En la obra literaria del escritor argentino Roberto Arlt, la imaginación no conduce a los personajes a la liberación, sino a la derrota definitiva. Su teatro está lleno de criaturas miserables que tratan de sobreponerse inútilmente a los continuos encontronazos con la vida cotidiana. Sus obras contemplan numerosos desdoblamientos imaginativos que permiten al autor introducir diferentes niveles en la ficción y plantear el teatro dentro del teatro. En La isla desierta, una de sus piezas más breves y representadas, los personajes de una triste oficina portuaria experimentan un cambio radical en sus vidas cuando dejan de trabajar en un sótano y son trasladados a la décima planta de un inmueble. Allí, a través de un inmenso ventanal, son reclamados por un sinfín de tentaciones que se encuentran más allá del mundo gris de la oficina. Los empleados descubren los beneficios de la luz natural, la llegada de los buques, el bullicio de la calle, los reclamos de la libertad, elementos que acaban desestabilizando la rutina administrativa. No obstante, es el relato de uno de los personajes, el mulato Cipriano, cuya memoria es esencialmente literaria, el que arrastra al resto de los oficinistas a la ensoñación y a la consiguiente derrota.

  11. Ongelijkheid als beleidsvraagstuk

    NARCIS (Netherlands)

    Wilterdink, N.

    2014-01-01

    Op het hoogtepunt van de hype rond het ongelijkheidsonder­zoek van Piketty presenteerde de WRR zijn verkenningHoe ongelijk is Nederland? Voor de onafhankelijke denktank is stelling nemen in een politiek vraagstuk als dat van ongelijkheid best ingewikkeld.

  12. MEMORE AL AMIKO

    Institute of Scientific and Technical Information of China (English)

    Osmo; BULLER

    1999-01-01

    Skuis min la novajo, ke mia amiko kajkolego Dai Song’en forlais nin por iam. Lakruela fatalo foriris lin, kiam li ankoraǚ estismeze de sia laboro, plena de planoj kaj tiel ju-ha. Kun muta senpovo ni devas subii al lasenkompata trudo de la sorto, kvankam la men-so ribelas kaj rifuzas kredi ke ipovas esti vero.

  13. Abraham Kuyper als theoloog

    Directory of Open Access Journals (Sweden)

    W. H. Velema

    1989-06-01

    Full Text Available Men zou in Nederland de herdenking van Kuypers honderdvijftigste geboortedag hebben kunnen aangrijpen als een gelegenheid om diens theologie en diens levenswerk in kerk en samenleving te evalueren. Niemand kan ontkennen dat er in genoemde publicaties iets van een evaluatie is te vinden.

  14. Kulturmorphologie als Zivilisationskritik

    DEFF Research Database (Denmark)

    Peters, Rikke Alberg

    2010-01-01

    Der Untergang des Abendlandes wird oft als dasjenige Werk betrachtet, das am tiefsten die national gefärbte Gegenüberstellung von Kultur und Zivilisation in der Zwischenkriegszeit geprägt und propagiert hat. Wie auch bei anderen Autoren der Konservativen Revolution, vor allem bei Thomas Mann und...

  15. Comentarios al Salto Social

    Directory of Open Access Journals (Sweden)

    Facultad de Ciencias Económicas

    1995-06-01

    Full Text Available 1. El Plan considera que la política social es un componente central de la estrategia macroeconómica. A diferencia de la administración Gaviria, lo social ha dejado de ser un asunto marginal, es consustancial al desarrollo y, por tanto, se le confiere una dimensión cualitativamente diferente.

  16. El Alcázar de Madrid. Del castillo Trastámara al palacio de los Austrias (Ss. XV-1543

    Directory of Open Access Journals (Sweden)

    Alonso Ruiz, Begoña

    2014-12-01

    Full Text Available The medieval Alcázar (fortress of Madrid was transformed into the residential palace of the Austrian dynasty in Spain from the reign of Charles I through that of Charles II. On Christmas Eve 1734, during the reign of the Bourbon king Philip V, the palace suffered a devastating fire, resulting in the construction of a new Royal palace, already baroque, on the same site. This research reconstructs the history – until now fragmented – of this lost medieval castle, contributing new source materials concerning the successive interventions carried out on the building. Specifically, this investigation focuses on the improvements realized during the period of the Catholic Monarchs and the first works commissioned by Charles V, prior to the definitive royal bond of 1536. This document marks the beginning of a new chapter in the constructive history of the building, when the old castle was transformed definitively into a residential palace, while highlighting the symbolic value of the Sala Rica and the rooms of protocol constructed during the Trastámara period.El alcázar medieval de Madrid se convirtió en la gran residencia de los Austrias desde la llegada de Carlos I al reinado de Carlos II. En la Nochebuena de 1734, reinando ya Felipe V de Borbón, el palacio sufrió un devastador incendio, resultado del cual se inicia la construcción del nuevo Palacio Real, ya barroco, sobre su solar. En esta investigación nos ocupamos de reconstruir la historia –hasta ahora fragmentada– de ese castillo medieval, aportando nuevos datos documentales acerca de las sucesivas intervenciones sufridas en el edificio. Nos centramos de forma especial en las obras realizadas en el período de los Reyes Católicos y en las primeras encargadas por Carlos V, antes de la definitiva real cédula de 1536 que marca el comienzo de un nuevo capítulo en la historia constructiva del edificio al transformarse de manera definitiva el viejo castillo en un palacio residencial

  17. Calculation of interaction of AlCl, AlCl2 and AlCl3 on Al4C3 (001) Al4CO4 (001) and Al2CO (001) planes

    Institute of Scientific and Technical Information of China (English)

    段少飞; 陈秀敏; 杨斌; 郁青春; 徐宝强; 刘大春

    2015-01-01

    To make sure the intermediate products of the carbothermic reduction of Al2O3 process, such as Al4CO4, Al2CO and Al4C3, and the interaction of AlCl, AlCl2, AlCl3 with Al4CO4, Al2CO and Al4C3, respectively, thermodynamic analyses were used to study the chloride reaction production of them under the vacuum situation. The stable structures and electronic properties of AlCl, AlCl2 and AlCl3 adsorbed on Al4CO4, Al2CO and Al4C3 were calculated by first-principles calculations by the CASTEP module in the Materials Studio program. The results show that the AlCl3 and AlCl2 molecules have decomposed on the plane of Al4C3 (001), while there are no obvious decomposition of AlCl3 and AlCl2 on Al4CO4 (001) and Al2CO (001) planes. The adsorption of AlCl on the Al4CO4 (001) and Al2CO (001) planes is stronger than that on the Al4C3(001) plane. The interaction strength of AlCl3, as well as AlCl2, with Al4CO4, Al2CO and Al4C3 is in the sequence of Al4CO4Al2CO>Al4C3.

  18. De GPS al mapa

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

    Full Text Available Las coordenadas Lambert obtenidas a partir de mediciones con equipos GPS de mano, llamados a veces navegadores, en ciertos casos confunden al usuario, por diferir claramente de su posición real al ser graficadas en un mapa del Instituto Geográfico Nacional (IGN: Esto puede resolverse con suficiente exactitud mediante una transformación de Molodensky, seguida de la correspondiente proyección cartográfica. Sin embargo, los tres parámetros necesarios para la transformación, supuestamente válidos para Costa Rica, se encuentran en muchas variantes y producen obviamente resultados diferentes. En este trabajo se analizan los fundamentos del problema y sus posibles soluciones, culminando con un estudio comparativo de ocho casos, que permite seleccionar los valores más adecuados para los parámetros.

  19. Derecho al desarrollo y globalidad

    OpenAIRE

    Álvarez Vita, Juan

    2014-01-01

    La presente disertación, que he intitulado Derecho al Desarrollo y Globalidad, consta de cuatropuntos principales:I. El derecho al desarrollo en el contexto de los derechos humanosII. La noción del derecho al desarrolloIII. El derecho al desarrollo en el marco de las llamadas generaciones de derechos humanosIV. El derecho al desarrollo y la aldea globalPalabras clave: derechos humanos, Derecho Natural, Derecho Positivo, sociedad global.

  20. Augmented Reality als Bildungsenhancement?

    OpenAIRE

    Damberger, Thomas

    2015-01-01

    Die Realität, die sich mithilfe von Datenbrillen und Smartphone Applikationen in die virtuelle Welt hinein ausdehnt, erfährt eine Form des Enhancements. Ein solches Enhancement kann unter bestimmten Voraussetzungen als Bildungsenhancement verstanden werden. Der Text befasst sich mit Formen der erweiterten Realität, ferner mit dem, um was es wesentlich bei der Bildung geht und zuletzt mit den Bedingungen, die erforderlich sind, um diesem Wesentlichen mit Hilfe von augmented reality besser zum ...

  1. Carta al editor

    Directory of Open Access Journals (Sweden)

    Harry Pachajoa

    2012-02-01

    Full Text Available Recently, Valencia et al., published a very interesting article called «Lipid profile in a group of patients with Turner’s syndrome at Clínica Universitaria Bolivariana in the city of Medellín between 2000 and 2009". An article which evaluated lipid levels in patients withTurner syndrome in a Colombian clinic, the study associated results of lipid profile with karyotype and other risk factors for coronary heart disease.

  2. Religion als soziale Deutungspraxis

    Directory of Open Access Journals (Sweden)

    Ulrike Lingen-Ali

    2016-12-01

    Full Text Available ENGLISH: During the last decades, the topos religion transformed into a powerful category of difference, which is also relevant for educationsystems and settings. Religion as a tool to differentiate between subjects is linked with power and dominance and, thus,with ideas about the constructed identities of “the other”. With this respects, religion functions as a code to define in- andexclusions and mark “the other”, e.g. “the Muslim” in predominantly Christian societies in Europe. Critical theories on racismenable to recognize, describe and define these practices and their effects. They can provide a useful tool to question and challengeintercultural and interreligious educational approaches which potentially reproduce and, thus, strengthen cultural/religiousdifferentiations. DEUTSCH: Die Differenz- und Heterogenitätskategorie Religion hat sich in den letzten Jahren im europäischen und auch deutschsprachigenDiskursraum zu einer medial, wissenschaftlich und politisch wirkmächtigen Kategorie entwickelt. Dabei zeigt sich Religion sowohlals soziale Unterscheidungspraxis (auch in pädagogischen Arrangements, als auch als Mittel zur Identifikation und Charakterisierungbestimmter Gruppen und Individuen als religiöse Subjekte. Religion stellt in diesem Zusammenhang einen Zugehörigkeitscodedar, mit dem Personen als natio-ethno-kulturell Andere markiert werden, wie die Markierung von MuslimInnen durchAngehörige der mehrheitlich christlichen Dominanzgesellschaft zeigt. Rassismuskritische Ansätze ermöglichen es zumeist eherimplizit an Rassekonstruktionen anschließende Unterscheidungen zu erkennen und zu beschreiben, den Bedingungen ihres Wirksamwerdensnachzugehen sowie ihre Konsequenzen zu bestimmen. Eine rassismuskritische und migrationspädagogisch informierteReligionspädagogik ermöglicht AkteurInnen, weniger auf gewaltvolle Unterscheidungspraxen angewiesen zu sein undalternative Veränderungs- und Handlungsmöglichkeiten zu

  3. Consideraciones sobre un nuevo y notable puñal calcolítico atribuible al grupo Treilles del Museu d´Arqueología de Catalunya en Barcelona

    Directory of Open Access Journals (Sweden)

    Rovira i Port, Jordi

    2004-12-01

    Full Text Available Althrough we were unaware of its concret origin, the Museu d´Arqueologia of Barcelona preserves in his collections a magnificent example of copper dagger assimilable to the series of daggers so-called «à encoche bilatérale » and «à soie courte crantée». These are pieces assimilated principally to the metallurgy of the pre-bell beakers of the Treilles Group, althrough certain pieces appear also in the prehistoric cultural groupes of Fontbuisse and Véraza. We present suggestions about its typology, filiation and the chronology of this dagger, as well as about its likely metallic composition.

    Aunque ignoramos su procedencia concreta, el Museu d´Arqueologia de Barcelona conserva en sus colecciones un magnífico ejemplar de puñal de cobre tipológicamente atribuible a las series de puñales denominados genéricamente como «à encoche bilatérale» y «à soie courte crantée». Se trata de piezas asimilables mayoritariamente a la metalúrgia precampaniforme del Grupo «des Treilles», aunque ciertos ejemplares aparecen también en los grupos culturales prehistóricos franceses de Fontbuisse y Véraza. En el artículo se efectúan apreciaciones sobre su tipologia, la filiación y la datación del puñal, así como sobre su probable composición metalográfica.

  4. Piezas metálicas de la Protohistoria. Navarra: Armas

    Directory of Open Access Journals (Sweden)

    Amparo CASTIELLA RODRÍGUEZ

    2009-10-01

    Full Text Available El presente artículo es un intento de ampliar el conocimiento acerca de los testimonios materiales pertenecientes a los pueblos protohistóricos asentados en Navarra. Entre los instrumentos metálicos se debe señalar el número de armas —hasta 111 piezas— clasificadas en diferentes grupos. Se ofrece una valoración arqueológica, dibujos e información cartográfica en apoyo a las conclusiones del trabajo.

  5. Establecimiento de los consumos de piezas de recambios

    Directory of Open Access Journals (Sweden)

    Liudmila Shikilouva

    2006-05-01

    Full Text Available En el presente artículo se presentan consideraciones necesarias respecto a la necesidad de prever en una empresa u organización los recambios para de manera ágil garantizar el flujo de producción o la capacidad de trabajo de los conjuntos y máquinas en sentido general. Seplantean ideas acerca de cómo presentar la formulación del cálculo de los recambios y de preceptos actuales técnico-económicos de este análisis. Sobre este particular se abordan los elementos esenciales de tres determinantes o factores que inciden en la previsión de los recambios, como son la ineficiencia en el logro de la calidad del proceso tecnológico, el trabajo del ejecutor y la calidad con que se efectúa la reparación de los conjuntos y máquinas. Para ilustrar los efectos que sobre estos determinantes influyen en mayor o menor magnitud, se elaboran los diagramas de Ichikawa necesarios, que se muestran sobre la base de la experienciapráctica los más significativos.

  6. La Bandera: pieza dramática en un acto

    Directory of Open Access Journals (Sweden)

    Nestor Madrid Malo

    1966-02-01

    Full Text Available La escena representa una estancia amplia y cuidadosamente amoblada. Es algo así como una sala de estar de las mujeres, una especie de gineceo, con espejos y cuadros en las paredes; consolas con la parte superior de mármol (debajo de los espejos; una cómoda, un escritorio y, -encima de este, el retrato del general; hay también un gran arcón de madera, un pequeño estante con libros y varias butacas y mecedoras con el fondo y el espaldar de paja; en la mitad, una mesa baja y redonda, encima de la cual hay un costurero, hilos, tijeras, etc.,

  7. IFIC expone grandes piezas del acelerador particulas de Ginebra

    CERN Multimedia

    2005-01-01

    The Institute for corpuscular physics of Valencia University exhibits from today great pieces coming from the particle accelerator of CERN in Geneva, an underground laboratory of high technologic level producing small atomic particles which it makes collide at very high energies to study the fundamental components of the matter and its interactions (1 page)

  8. Teatro al aire libre

    Directory of Open Access Journals (Sweden)

    Philippe Canac

    2016-11-01

    Full Text Available Siendo cada vez más frecuentes y numerosas las peregrinaciones a la basílica de Notre Dame, de Laus (Altos Alpes, su capacidad resultaba hace tiempo insuficiente para acoger a sus peregrinos. Este fue el motivo de crear, en un terreno situado ante el atrio de la basílica, un conjunto, que permitiese celebrar misas al aire libre, ceremonias litúrgicas o representaciones de teatro religioso y que dispusiese de todas las posibilidades para conseguir la libertad del juego escénico.

  9. Rheocasting Al matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Girot, F.A.; Albingre, L.; Quenisset, J.M.; Naslain, R.

    1987-11-01

    A development status account is given for the rheocasting method of Al-alloy matrix/SiC-whisker composites, which involves the incorporation and homogeneous distribution of 8-15 vol pct of whiskers through the stirring of the semisolid matrix melt while retaining sufficient fluidity for casting. Both 1-, 3-, and 6-mm fibers of Nicalon SiC and and SiC whisker reinforcements have been experimentally investigated, with attention to the characterization of the resulting microstructures and the effects of fiber-matrix interactions. A thin silica layer is found at the whisker surface. 7 references.

  10. Frequently Asked Questions about ALS and the ALS Registry

    Science.gov (United States)

    ... Muscular Dystrophy Association (www.mda.org) The Les Turner ALS Foundation (www.lesturnerals.org) Back to Top ... als. Back to Top Why was incidence (new cases of ALS) not provided in the report? Date of diagnosis is needed to calculate incidence. ...

  11. Derivados vinculados al seguro.

    Directory of Open Access Journals (Sweden)

    De Paz Cobo, Sonia

    2003-01-01

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

  12. Gliricidia sepium al establecimiento

    Directory of Open Access Journals (Sweden)

    J. L. Valle

    2004-01-01

    Full Text Available Se asoció Cenchrus ciliaris (Cc y Gliricidia sepium (Gs para evaluar la producción de biomasa y la composición química de los forrajes en la fase de establecimiento, en el estado de Morelos, México, en condiciones de trópico seco. Se empleó un análisis de varianza con diseño en bloques al azar, en donde T1 fue pasto solo, T2 Cc más Gs con 5,000 plantas ha-1 y el T3 Cs más Gs con 14,285 plantas ha-1. Se midió la producción de forraje individual y asociado con materia seca (t MS/Ha, la altura (A en cm, la proteína cruda (PC%, las fracciones de fibra (FDN% y FDA% y la digestibilidad in vitro de la materia seca (DIVMS%. El T3 tuvo una mejor producción de biomasa (P0.05. La asociación de 14,285 plantas ha-1 de G. sepium con pasto Cenchrus ciliaris mejoró la producción de biomasa y la disponibilidad total de nutrientes por superficie cultivada al establecimiento

  13. AL-SIYAQ FI TARJAMAH KITAB AL-LUGHAH AL-'ARABIYAH ILA AL-LUGHAH AL-INDUNISIYAH

    Directory of Open Access Journals (Sweden)

    Devita Zuliati

    2016-06-01

    Full Text Available This study aimed at analyzing the translation of 53 poems in Tata Bahasa Arab book written by Chatibul Umam, et al. in view of the context theory. This study was based on a contextual translation theory that the understanding the right and proper context of Arabic texts translated into Indonesian plays an important role in determining the quality of a translation that is easily understood, contextual and functional. The qualitative data were read using the linguistic approach and critical translation. This study concluded that the translation work of Chatibul Umam, et al. tended to be literal not based on the complete understanding of the context, internal context (linguistic context and socio-cultural context of the texts. The role of the external context of the texts is less utilized in the translation process of poetry (nazham, so that the translation of the book is neither communicative nor functional.

  14. Modeling neuronal vulnerability in ALS.

    Science.gov (United States)

    Roselli, Francesco; Caroni, Pico

    2014-08-20

    Using computational models of motor neuron ion fluxes, firing properties, and energy requirements, Le Masson et al. (2014) reveal how local imbalances in energy homeostasis may self-amplify and contribute to neurodegeneration in ALS.

  15. AL-USRCRN Station Information

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Documentation of United States Alabama Regional Climate Reference Network (AL-USRCRN) installations in 2006. Installations documented are for AL-USRCRN pilot project...

  16. ANÁLISIS DE OBRAS MUSICALES VENEZOLANAS Y EUROPEAS DE LOS SIGLOS XVIII, XIX Y XX REFERENTES AL REINO ANIMAL

    Directory of Open Access Journals (Sweden)

    Naudy Trujillo Muscia

    2012-09-01

    venezolanos y europeos de los siglos XVIII, XIX y XX. Los resultados indican a las aves silvestres como las más tratadas en piezas musicales tanto en Europa como en Venezuela; manifiestan también una proporción mayor de piezas musicales que tratan los animales de producción versus animales domésticos en Venezuela, mostrándose lo contrario en el continente europeo. Se concluye, en primer lugar, que tanto en Venezuela como en Europa, la cultura humana busca enaltecer la fauna silvestre, ya sea de forma naturalista o romántica; se confirma el fuerte arraigo de la mentalidad agropecuaria venezolana y su importancia en el desarrollo de la cultura nacional a la par que en Europa; los resultados reflejan el poco contacto con áreas verdes abiertas y sistemas de producción agropecuarios que poseían los compositores y público académico de la época. Esta investigación fomenta la interdisciplinariedad en la sociedad científica venezolana, haciendo aportes científicos al desarrollo de la cultura, además de servir a docentes, terapeutas musicales, historiadores y la sociedad en general en sus investigaciones y ocupaciones al generar nuevas preguntas en el campo científico de la psiquis humana dentro de la relación hombre/animal y brindar nuevos conocimientos a la ciencia histórica de la Medicina Veterinaria y la Música Universal.

  17. COMENTARIO AL CASO PINOCHET

    Directory of Open Access Journals (Sweden)

    Alberto Contreras Clunes

    2002-01-01

    Full Text Available El fallo en el caso Pinochet tiene distintas formas de ser analizado. De partida, desde un punto de vista político, también constitucional, del derecho penal. Sin embargo, nos abocaremos al estudio desde el punto de vista procesal, en especial a lo referido al Debido Proceso. Para ello se analizará los presupuestos, la solución dada por la Excma. Corte Suprema y las consecuencias del mismo. Además, se criticará la solución dada, desde la óptica de las garantías procesales del imputado, contenidas en el nuevo proceso penal y lo dispuesto en la Constitución y la Convención Americana de Derechos Humanos. Finalmente, se argumentará en favor de una interpretación finalista y armónica de la Constitución y los tratados internacionales de derechos humanos.The verdict of the Pinochet Case has different ways of being analyzed: from the political, the constitutional, and the penal law points of view. However, we will approach this study from the legal point of view, especially to that referred to as the Proper Process. To do this, the budgets, the solution given by the Most Excellent Supreme Court, and its consequences will be analyzed. Furthermore, the given solution will be criticized from the point of view of the legal guarantees of the accused contained in the new penal process and what is contained in the Constitution and in the American Convention of Human Rights. In conclusion, we will argue in favor of a final and harmonious interpretation of the Constitution and the international agreement of human rights.

  18. Carta al Editor

    Directory of Open Access Journals (Sweden)

    Darío Maldonado Romero

    1991-03-01

    Full Text Available

    Bogotá, 01 de Agosto de 1990
    Señores
    Miembros del Consejo Editorial
    Academia Nacional de Medicina
    E.S.D.

    Señores doctores:

    Con toda consideración y respeto me permito agregar algunas anotaciones al escrito del Académico Alberto Cárdenas Escobar, aparecido en el No. 22 de Medicina, para destacar algunos aspectos de la personalidad del doctor Alberto Schweitzer galardonado con el Premio Nobel de la Paz.

    A los 30 años de edad tomó una decisión dramática: Estudiar Medicina para trabajaren el África Ecuatorial. Cuando terminó sus investigaciones sobre enfermedades tropicales y sus prácticas hospitaLarias, partió para el Gabon al pequeño pueblo de Lambarené. La tarea era desconsoladora; La atención médica había que prestarla al aire libre; iba con su esposa, como enfermera y amanuense, y no se encontraba ni un intérprete, ni un ayudante. Cuando le llegaron la medicina y el equipaje hubo que acomodarlos en un viejo gallinero abandonado; el calor era insoportable y le venían enfermos de varias millas a la redonda, a pie o en Canoas.

    Las enfermedades más difundidas eran Malaria, Disentería, estreptococias y la más mortífera, la Tripanosomiasis Gambiense, para la que empezaban a llegar medicinas nuevas eficaces y las medidas preventivas como el suministro de agua potable y enmallado de ventanas impedían muchas contaminaciones.

    Pero la que causaba mayores dificultades y trabajo era la Mycobacteriasis Anestesiante, incurable, de difícil diagnóstico, afectando a varios miembros de la misma familia, de aspecto horripilante, con complicaciones neuríticas muy dolorosas, frecuente ceguera, e invalideces y procesos erisepelatososacrotéricos, que exigían acompañante para el cambio y lavado de vendas y suministro de alimentos.

    A menos de un año de

  19. Konsep Hati Menurut al-Hakim al-Tirmidzi

    Directory of Open Access Journals (Sweden)

    Ryandi Ryandi

    2014-03-01

    Full Text Available Dalam khazanah sufi, hati atau qalb adalah salah satu term sentral yang dibahas secara mendalam. Karena bagi sufi, hati adalah entitas metafisik (latifah rabbaniyyah ruhaniyyah yang dengannya manusia dapat mencapai ma’arifatullah dan mengetahui rahasia-rahasia-Nya. Salah satu sufi klasik yang mengkaji hati secara mendalam adalah Abu ‘Abdullah ibn ‘Ali ibn al-Hasan ibn Basyar al-Hakim al-Tirmidzi (w 320 H. Ia mengkonsepsikan hati sebagai entitas metafisik universal yang terkandung di dalamnya tingkatan-tingkatan batin (maqamat al-qalb, yaitu: sadr, qalb, fu’ad, dan lubb. Pemetaan ini dimunculkan sesuai dengan fungsi linguistiknya dan penggunaannya dalam al-Qur’an dan Hadis Nabi SAW. Tiap-tiap tingkatan batin tersebut berkaitan dengan tingkatan pengetahuan, keilmuan, spiritual, dan jiwa manusia. Kaitan tersebut menunjukan bahwa qalb merupakan eksistensi ruhani manusia (al-kainunah al-ruhiyyah, yang berfungsi sebagai instrumen penyempurna bagi manusia (al-jihaz al-mutakamil li al-insan yang meliputi seluruh kekuatan dan potensi manusia: ruhani, ‘aqliyah, dan kehendak, di mana manusia dengannya dapat merasa, berpikir, mengetahui, bahkan dapat mencapai ma’rifatullah dan dekat dengan-Nya.

  20. Editorial: Cartas al Editor

    Directory of Open Access Journals (Sweden)

    Guillermo Llanos

    2006-06-01

    Full Text Available En todas las revistas biomédicas del mundo existe una sección habitual denominada como el título de este editorial y que en Colombia Médica la llamamos correspondencia. Este espacio tiene como objetivo fundamental que los lectores escriban a los autores (investigadores comentando los artículos que se han publicado en números anteriores de la revista. Las cartas son, entonces, breves comentarios de desacuerdo o acuerdo (conceptual, metodológico, interpretativo sobre falencias ubicadas por un lector alerta al tema debatido en cualquiera de las secciones como en los artículos originales, editoriales, revisiones, presentación de casos, etc. publicados previamente en la revista. Las cartas deben permitir el intercambio de opiniones y formas de pensar y analizar los problemas planteados entre los autores y los lectores. En ocasiones una serie de cartas motivadas por un artículo original puede ser tan o más interesante como el artículo que generó la correspondencia. Las cartas son también un formato adecuado para comunicar un hecho novedoso de una observación clínica juiciosa no descrita antes. Un ejemplo de ello es la carta de un gineco-obstetra australiano cuando informó a Lancet los primeros efectos adversos informados de la talidomida. Colombia Médica, a pesar de mantener vigente esta sección, no ha sido muy afortunada en establecer una buena cultura del envío de cartas al editor. Pero últimamente han llegado juiciosas observaciones a las cuales se les ha dado prioridad en su publicación. Toda carta que comenta los hallazgos de un artículo es enviada a los autores para su respuesta, porque ello genera el debate académico buscado, y luego se publican, tanto la carta como su respuesta. El Estilo Vancouver recomienda que la carta y su respuesta deban ser breve, no pasar de dos o tres párrafos y contener sólo cuatro o cinco referencias. En lo posible (a menos que sea indispensable no presentar ni cuadros ni gráficos. El t

  1. Del presidencialismo omnímodo al presidencialismo disfuncional

    OpenAIRE

    Manuel Villa Aguilera

    2014-01-01

    La institución presidencial se estableció como la pieza central cohesionadora del régimen político mexicano, crucial para la estabilidad pero responsable también de deformaciones del sistema representativo de tres poderes. Objetivo principal en el desmantelamiento de las dimensiones autoritarias del régimen, el presidencialismo omnímodo prácticamente fue desmontado, avanzando en dis - tribución de poderes y pluralidad partidaria. La Presidencia y el Legislativo no han resultado funcionales a ...

  2. Malamih al-Ashwat al-'Arabiyyah wa Makharijaha

    Directory of Open Access Journals (Sweden)

    Amrah Muhammad Kasim

    2015-12-01

    Full Text Available This writing discusses on al-ashwat al-‘arabiyyah that is known with “phonetic” term. It talks and interprets makharij al-huruf or place for producing sounds and also processing production of sounds by parts of mouth in Arabic language. The problems of sounds and its systems in Arabic language have been conducted by the scholars of al-ashwat al-‘arabiyyah attractively, neatly, and detail and gotten ahead the phonetic western scholars. Part of their analysis results formulate the study about al-ashwat al-sakinah (al-Shamit is known with vocal and consonant sounds in research questions shawait – shawamit. Ibnu Jinni has formulated “harakat”(wowel in Arabic language and dimension of letter  mad and liyn on alif  letter - waw - ya’ (ا و ي, from these letters create  harakat fathah, dammah, and kasrah. Moreover, in this writing also exist the description of hija’i letters and its makhraj that are correct from parts of mouth and the unity of coordinative sounds that produce sounds in morphemes arrangement, in one word that produces meaning. The result of phonological study has divided al-ashwat to be kinds of sound like the pronounced sounds, produced sounds from mouth, and heard sound.

  3. Construcción de modelos computacionales para el análisis de esfuerzos mecánicos de piezas óseas utilizando imágenes de TC: aplicación a la articulación gleno-humeral Construction of computational models for the stress analysis of the bones using CT imaging: application in the gleno-humeral joint

    Directory of Open Access Journals (Sweden)

    Adrián Cisilino

    2008-12-01

    Full Text Available Se presenta en este trabajo una metodología para el procesamiento de imágenes de estudios de TC para la construcción de modelos computacionales de piezas óseas. Los modelos computacionales son utilizados para el análisis de esfuerzos utilizando el Método de los Elementos Finitos. Las constantes elásticas del tejido óseo son calculadas a partir de los datos de densidad de las TC. La metodología propuesta es aplicada en la construcción de un modelo para el análisis de la articulación gleno-humeral.A methodology for the construction of computational models from CT images is presented in this work. Computational models serve for the stress analysis of the bones using the Finite Element Method. The elastic constants of the bone tissue are calculated using the density data obtained in from the CTs. The proposed methodology is demonstrated in the construction of a model for the gleno-humeral joint.

  4. La resistencia bacteriana transmitida al hombre a través de los alimentos y el uso responsable de los antimicrobianos como moduladores de crecimiento

    OpenAIRE

    Gimeno, Emilio J.

    2001-01-01

    El objetivo de la presente comunicación es hacer un aporte para esclarecer a la opinión pública sobre la teoría y práctica de la resistencia bacteriana en relación con los moduladores de crecimiento, aportando datos, informes e ideas basadas en aspectos técnicos y hechos prácticos , científicamente demostrados sobre información consolidada.

  5. Porosity of porous Al alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Two porosity models of porous Al alloys with different pore types (ball and polygon shape) were established. The experimental results coincide well with theoretical computations. The porosity of Al alloys (Prc) consists of three parts, porosity caused by preform particles (Prp), additional porosity (Pra), and porosity caused by solidification shrinkage (Prs). Prp is the main part of Prc while Pra is the key for fabricating porous Al alloys successfully in spite of its little contribution to Prc.

  6. Ansiedad al tratamiento odontológico: Características y diferencias de género

    Directory of Open Access Journals (Sweden)

    Caycedo, Martha

    2008-09-01

    Full Text Available Este trabajo hace parte de un estudio mayor sobre la convergencia entre el reporte del odontólogo acerca de la ansiedad de sus pacientes y las respuestas de los pacientes a dos escalas de ansiedad ante el tratamiento odontológico, llevado a cabo con una muestra de 132 odontólogos y sus correspondientes 913 pacientes en Bogotá, Colombia. Se presentan los datos correspondientes a las respuestas de los pacientes a dos instrumentos de autorreporte acerca de la ansiedad ante los tratamientos odontológicos. Tanto la escala MDAS (Escala de Ansiedad Dental Modificada como la SDAI (Inventario de Ansiedad Dental-versión corta, permitieron identificar una distribución similar en los diferentes niveles de severidad en la muestra de este estudio. Adicionalmente, se pudo observar que los contextos más ansiogenos son los que incluyen jeringas y agujas (47,2%, la anticipación de la extracción de una pieza dental (34,7% y la anticipación del uso de la fresa dental (25,4%. Por otra parte, se observó niveles de ansiedad levemente mayores en mujeres que en hombres, este aspecto se evidencia tanto en los resultados de las escalas SDAI y MDAS como en la clasificación reportada por los odontólogos. Los resultados se discuten haciendo énfasis en la importancia de la identificación temprana de este desorden, del entrenamiento a odontólogos para su manejo; así como, del trabajo interdisciplinario para brindar al paciente una alternativa que promueva el uso de habilidades de autorregulación emocional.

  7. Al versus Si competition in FeSiAl alloys

    Energy Technology Data Exchange (ETDEWEB)

    Legarra, E. [Dpto. Electricidad y Electronica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco (UPV/EHU), CP 644, 48080 Bilbao (Spain)], E-mail: estibaliz.legarra@ehu.es; Apinaniz, E. [Dpto. Fisica Aplicada I, Escuela de Ingenieria Tecnica Superior, Universidad del Pais Vasco, Alameda de Urquijo s/n 48013 Bilbao (Spain); Plazaola, F. [Dpto. Electricidad y Electronica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco (UPV/EHU), CP 644, 48080 Bilbao (Spain); Jimenez, J.A. [Centro Nacional de Investigaciones Metalurgicas (CENIM), Avda. Gregorio del amo 8, 28040 Madrid (Spain); Pierna, A.R. [Chemical Engineering and Environmental Department, UPV/EHU, Box 1379, 20008 San Sebastian (Spain)

    2008-10-15

    In FeSiAl alloys, when Si substitutes for Al, important changes take place in the magnetism as well as in the structural properties. Alloys in the two composition series Fe{sub 75}Al{sub 25-x}Si{sub x} (x=0, 7.5, 12.5, 17.5, 25) and Fe{sub 70}Al{sub 30-x}Si{sub x} (x=0, 9, 15, 21, 30) were prepared by induction melting; afterwards they were crushed and then annealed in order to recover the DO{sub 3} stable phase. The deformed FeAl samples show larger lattice parameters than the ordered ones; however, this difference ({delta}a) decreases when Si substitutes for Al until it becomes zero (i.e. until the ordered samples and the deformed ones have the same lattice parameters). This trend is the same for both sample series and does not depend on the Fe content of the alloy. However, the magnetization has a different behaviour depending on the Fe content. For deformed Fe{sub 75}Al{sub 25-x}Si{sub x} alloys the saturation magnetization decreases with increasing Si content while for Fe{sub 70}Al{sub 30-x}Si{sub x} deformed alloys the saturation magnetization has a plateau in which the saturation magnetization values do not vary.

  8. Formación de capa híbrida al cementar postes metálicos y de fibra de vidrio en dientes tratados endodónticamente Hybrid layer formation using metal post and fiber post into endodontically trated canal roots

    Directory of Open Access Journals (Sweden)

    V. Valenzuela Aránguiz

    2010-04-01

    Full Text Available Se evaluó al microscopio electrónico de barrido (MEB la efectividad de la adhesión lograda dentro de conductos tratados utilizando dos sistemas adhesivos, uno de fotocurado (Single Bond y otro dual (Prime & Bond NT + Self-Cure Activator y dos sistemas de postes (fibra de vidrio y metálicos. El objetivo fue evaluar la formación de capa híbrida y tags de resina al interior de los conductos radiculares. Método: Doce piezas dentarias fueron preparadas para recibir un poste. Se dividieron en dos grupos de 6 piezas, a cada uno de los cuales se les colocó un tipo de poste. Ambos grupos fueron subdivididos en dos, aplicándoles distintos adhesivos, la resina de cementación RelyX ARC y el poste correspondiente. Las muestras fueron cortadas longitudinalmente y preparadas para la observación al MEB. Resultados: No se evidenciaron diferencias en cuanto al espesor de la capa híbrida entre los grupos. Se concluye que la capa híbrida y tags de resina formados dentro de los conductos utilizando ambos sistemas de postes y diferentes sistemas adhesivos, no son satisfactorios.The goal of this study was to evaluate the adhesive effectiveness attained in root canals endodontically treated with a scanning electronic microscope (SEM. We used two adhesive systems (Single Bond and Prime&Bond NT + Self Cure Activator and two post systems (fiberglass and metallic. The main objective was to evaluate the hybrid layer and resin tag formation inside each root canal. Twelve teeth were used, which were prepared for receiving the post. The teeth were divided into two groups of 6 pieces each. Each group received one type of post. In turn, each group was subdivided in two (a total of 4, receiving different adhesives, the cementation resin RelyX ARC and the corresponding post. The samples were cut longitudinally and prepared to be scrutinized with the microscope. The results showed that the adhesion inside the canal roots was not reliable. No difference regarding the

  9. Thermal Modeling of Al-Al and Al-Steel Friction Stir Spot Welding

    Science.gov (United States)

    Jedrasiak, P.; Shercliff, H. R.; Reilly, A.; McShane, G. J.; Chen, Y. C.; Wang, L.; Robson, J.; Prangnell, P.

    2016-09-01

    This paper presents a finite element thermal model for similar and dissimilar alloy friction stir spot welding (FSSW). The model is calibrated and validated using instrumented lap joints in Al-Al and Al-Fe automotive sheet alloys. The model successfully predicts the thermal histories for a range of process conditions. The resulting temperature histories are used to predict the growth of intermetallic phases at the interface in Al-Fe welds. Temperature predictions were used to study the evolution of hardness of a precipitation-hardened aluminum alloy during post-weld aging after FSSW.

  10. Philosophieren als Unterrichtsprinzip im Mathematikunterricht

    Science.gov (United States)

    Meerwaldt, Diana

    Philosophieren und Mathematik scheinen zunächst gegensätzliche Bereiche zu sein, die sich kaum vereinbaren lassen. Dies trifft für eine Auffassung zu, die Philosophieren als "Gerede" disqualifiziert und Mathematik als eine reine "Formelwissenschaft" begreift. Beide Auffassungen werden den Gegenständen nicht gerecht.

  11. El miedo al rey

    Directory of Open Access Journals (Sweden)

    François FORONDA

    2007-01-01

    Full Text Available La peur du roi. Sources et premières réflexions à propos d’une émotion aristocratique dans la Castille du XIVe siècleFace à un roi qui à présent pousse les effets de son ire jusqu’au meurtre pour faire le vide autour de lui et imposer sa différence souveraine, ses parents et les riches hommes, soit les principaux visés par cette politique de l’arbitraire qui enfreint les règles du jeu autant qu’elle contribue à les redéfinir, disent la peur (metus qu’ils ressentent, qu’ils utilisent aussi afin de donner à leur stratégie de pouvoir un fondement légitime. Et l’expression de cette émotion politique, qui tend à se muer en un stéréotype d’un discours aristocratique d’opposition, surtout présente dans les chroniques, mises ici en relation ici avec d’autres sources, notamment des correspondances, marque profondément l’histoire des relations souvent conflictuelles au sein de cette compagnie en définitive très étroite pendant un siècle, de la fin du XIIIe siècle à la fin du XIVe siècle. Cet article se propose d’ébaucher une première réflexion sur le sujet et d’en présenter les principales sources.El miedo al rey. Fuentes y primeras reflexiones acerca de una emoción aristocrática en la Castilla del siglo XIVFrente a un rey que ahora lleva hasta la muerte los efectos de su ira para hacer el vacío entorno a su persona e imponer su soberana, sus parientes y ricos hombres, o sea los principales afectados por esta política de la arbitrariedad que rompe las reglas del juego a la vez que contribuye a redefinirlas, dicen el miedo (metus que sienten, que utilizan también para darle a su estrategia de poder un fundamento legítimo. Y la expresión de esta emoción política, que tiende a convertirse en un estereotipo de un discurso aristocrático de oposición, sobre todo presente en la crónicas, aquí puestas en relación con otras fuentes, en particular cartas, marca profundamente la historia de

  12. Creación de Habilidades y Competencias a través del Empleo de las Nuevas Tecnologías para el Apoyo al Proceso de Aprendizaje (Building Skills and Competences Through the Use of New Techonologies to Support Learning Process

    Directory of Open Access Journals (Sweden)

    Luis Camilo Ortigueira-Sánchez

    2016-03-01

    Full Text Available Spanish abstract En el presente artículo se explora la aplicabilidad, utilidad y factibilidad del uso de las nuevas tecnologías para fomentar el aprendizaje, el autoestudio, y el trabajo en grupo. En especial se hace referencia a las social media tales como Twitter, Prezi u otras y la formación de redes grupales de trabajo. Mediante un cuestionario, se indaga en aquellas herramientas que han sido de mayor interés y que han satisfecho en mayor o menor medida las expectativas de los alumnos con diferentes tecnologías aplicadas a la docencia. Se obtiene además información que corrobora que el empleo de estas unido a otras más tradicionales, como la docencia presencial y las videos conferencias, cobran una mayor importancia en el desarrollo de habilidades imprescindibles para culminar con éxito los estudios; aportando además una competencia necesaria para la futura incorporación al mercado laboral. English Abstract In this paper the applicability, utility and feasibility of using new technology is explored to encourage learning, self-study and group work. In particular reference to social media such as Twitter, Prezi or other group and the formation of networks is done. Through a questionnaire, investigates those tools that have been of greatest interest and have met to a greater or lesser extent the expectations of students with different technologies applied to teaching. Information that corroborates that the use of these together with other more traditional, such as classroom teaching and video conferences are increasingly important for developing essential skills to successfully complete the studies; also providing a necessary competence to obtain further future incorporation into the labor market.

  13. Quantum dots formed in InSb/AlAs and AlSb/AlAs heterostructures

    Science.gov (United States)

    Abramkin, D. S.; Rumynin, K. M.; Bakarov, A. K.; Kolotovkina, D. A.; Gutakovskii, A. K.; Shamirzaev, T. S.

    2016-06-01

    The crystal structure of new self-assembled InSb/AlAs and AlSb/AlAs quantum dots grown by molecularbeam epitaxy has been investigated by transmission electron microscopy. The theoretical calculations of the energy spectrum of the quantum dots have been supplemented by the experimental data on the steady-state and time-resolved photoluminescence spectroscopy. Deposition of 1.5 ML of InSb or AlSb on the AlAs surface carried out in the regime of atomic-layer epitaxy leads to the formation of pseudomorphically strained quantum dots composed of InAlSbAs and AlSbAs alloys, respectively. The quantum dots can have the type-I and type-II energy spectra depending on the composition of the alloy. The ground hole state in the quantum dot belongs to the heavy-hole band and the localization energy of holes is much higher than that of electrons. The ground electron state in the type-I quantum dots belongs to the indirect X XY valley of the conduction band of the alloy. The ground electron state in the type-II quantum dots belongs to the indirect X valley of the conduction band of the AlAs matrix.

  14. La artillería naval : apuntes sobre el suministro al arsenal de la Carraca

    Directory of Open Access Journals (Sweden)

    José Quintero González

    2003-01-01

    Full Text Available El empleo generalizado del cañón de hierro posibilitó en gran medida la renovación de la Armada, muy limitada hasta entonces por la reducida oferta de los cañones de bronce. En España desempeñó un papel destacado en todo el proceso la fábrica de cañones de Liérganes (Cantabria, que hacia la década de los años veinte del siglo XVIII logró una producción de quinientas piezas anuales, así como la munición necesaria para dotarlas. Por lo que respecta al arsenal de La Carraca, la provisión de artillería representaba un problema complejo tanto por las dificultades de mantener las existencias necesarias en cada momento, como por la diversidad de elementos que componían el equipamiento artillero de una embarcación de guerra. En cualquier caso, el Arsenal consiguió mantener unos niveles de suministro aceptables, aunque en determinadas circunstancias se observaran ciertos desequilibrios entre los calibres demandados por las embarcaciones y los existentes en la base naval carraqueña.The widespread use of the iron gun made it possible the renewai of the Army to a large extent, as that was very limited so far for the reduced offer of bronze gun. In Spain, the guns factory in Liérganes (Cantabria played an important role in the whole process as it reached a production of about five hundred pieces a year in the second decade of the eighteenth century, as well as the necessary munitions to provide them. With regard to the arsenal of La Carraca, the artillery provision meant a rather complicated probiem both for the difficulty in keeping the necessary stock at all times and for all the different elements which formed the artillery equipment of a warship. In any case, the Arsenal could maintain acceptable levels of supply, although in certain circumstances there were some differences between the calibres the ships demanded and those others in the Naval Base of La Carraca.

  15. Diseño de producto de una red anti cínifes portable y auto plegable en material textil

    OpenAIRE

    2016-01-01

    Monet es una red anti cínifes que previene las enfermedades transmitidas por los mismos. El producto consta de una malla protectora, una carcasa, una estructura de montaje y un sistema de auto plegado, que es su mayor aportación y diferenciación del resto de mosquiteras. Está diseñado para ocupar el mínimo espacio y ser lo más ligera posible. Aportando unas grandes calidades y prestaciones mediante materiales reciclados. Monet es reparable, todas sus piezas son sustituibles ...

  16. LA CONTABILIDAD MEDIOAMBIENT AL: Una fuente inagotable para la investigación universitaria en el Perú

    OpenAIRE

    Polar Falcón, Ernesto Augusto; Facultad de Ciencias Contables, Universidad Nacional Mayor de San Marcos

    2014-01-01

    En marzo de 1999, las Sociedades Cubanas de Contabilidad, Auditoria, Costos y Finanzas de la Asociación Nacional de Economistas de Cuba realizaron las Primeras Jornadas Científicas: Contabilidad 99 Calidad-Eficiencia-Competitividad, con asistencia de muchos Contadores Públicos y Economistas de América Latina; y de España y Portugal, aportando nuevos temas de discusiones sobre el avance de las ciencias contables en Europa. Uno de los trabajos que más ha llamado la atención se titula: "Contabi...

  17. EKSKURSO AL CANGYAN-MONTO

    Institute of Scientific and Technical Information of China (English)

    Verkita; de; Li; Shijun

    1999-01-01

    La Pekina Esperanto-Asocio preskaǚ sta-rigis tradicion organizi ekskurson printempe kajaǚtune. En la pasinta jaro, ni ekskursis al In-terna Mongolio kaj habis agrablajn renkontiojnkun geesperantistoj en Huhehot kaj Baotou. i-

  18. Predicción numérica del afino de los granos en la zona afectada por la temperatura (ZAC para aportes de multipasadas durante el proceso de soldeo SMAW en el acero al Cr-Mo-V

    Directory of Open Access Journals (Sweden)

    Mazur, Z.

    2002-02-01

    Full Text Available The methodology of prediction of the heat-affected zone (HAZ microstructure in a multiple-bead welds of the two layers of 1.25Cr-1Mo-0.25V steel using SMAW deposition process is presented. A computer program was developed to calculate extension zones of interest of two layer multipass weld-beads HAZ and predict a percentage of HAZ coarse grains refinement for determined welding parameters, preheating temperature and weldbead overlap. The computer model has been validated by experiment depositing a series of two-layer weld-beads getting reasonable concordance of model prediction and measured during experiment structural HAZ distribution. Keywords HAZ microstructure. Numerical simulation. Cr-Mo-V steel. Two-layer multipass weld-beads

    Se presenta una metodología de predicción de las dimensiones de la zonas que ocupan distintos tamaños de grano de la zona afectada por la temperatura (ZAC, en los aportes de multipasadas de dos capas, aplicada al acero de baja aleación 1,25Cr-1Mo-0,25V por el soldeo SMAW. Se desarrolló un programa por ordenador para calcular la extensión de las regiones de distintos tamaños de grano en la ZAC de multipasadas de dos capas y predecir el porcentaje de afino de los granos gruesos de la ZAC para determinados parámetros de soldeo, temperatura de precalentamiento y solapamiento de los cordones. Se llevó a cabo la validación del modelo realizando una comparación con los resultados experimentales aportando varios cordones de soldadura en dos capas, obteniendo una razonable concordancia entre la predicción del modelo y la distribución estructural de la ZAC medida durante el experimento. Palabras clave Microestructura de la ZAC. Simulación numérica. Aceros al Cr-Mo-V. Soldadura SMAW. Cordones múltiples de soldadura de dos capas.

  19. Al clamor de les vuvuzeles

    Directory of Open Access Journals (Sweden)

    Javier Olivera Betrán

    2010-09-01

    Full Text Available El Mundial de Futbol de Sud-àfrica ha situat l’Àfrica al mapa mundial i ha mostrat al món el triomf de l’estil de futbol d’Espanya basat en la col·lectivitat, l’esperit d’equip, la humilitat, la cohesió interna i el joc bonic. L’organització africana, seriosa i eficaç, ha sabut mobilitzar i il·lusionar la població del país que ha participat en el mundial des de l’orgull de ser africà, amb l’esperit alegre, festiu i també reivindicatiu de la gent de l’Àfrica. Aquest esdeveniment suposa el llançament de la marca “Sud-àfrica” al món amb un avís clar d’optar a l’organització d’uns primers Jocs Olímpics a Àfrica (potser els de 2020. S’obre una finestra d’esperança al segle xxi per al continent perdut de la mà de l’esport espectacle tan universal, massiu, emocional i mercantil que també es juga a la canxa de la política i de l’economia.

  20. Al Zubarah - eine vergessene Legende

    DEFF Research Database (Denmark)

    Kinzel, Moritz

    2014-01-01

    Die im 18. Jahnhundert an der Nordwestküste Katars entstandene Handelsstadt Al Zubarah bildet den Forschungsschwerpunkt des Qatar Islamic Archaeology and Heritage Projects (QIAH), das die Universität Kopenhagen in Zusammenarbeit mit der Katarischen Museumsbehörde (QMA) seit 2009 durchführt. Neben...... der archäologischen Erforschung der Stadtanlage und ihrer Elemente, stehen die Erhaltung und Präsentation des Fundortes und seiner Bauten von Anfang an ebenfalls im Fokus der Arbeiten. Auf Grundlage der Projektarbeit wurde 2011 der Antrag auf Aufnahme von Al Zubarah in die Weltkulturerbe eingereicht....... Die Stadtanlage ist ein einzigartiges Beispiel für eine planmäßig angelegte Stadt mit allen typischen Elementen einer orientalischen Stadt: Souq, Moschee, Hofhausquartiere und turmbewehrter Stadtmauer. Die Blütezeit von Al Zubarah währte nur gut 50 Jahre. 1811 wurde sie bereits wieder zerstört. Einige...

  1. Conjuntivitis alérgica

    Directory of Open Access Journals (Sweden)

    Alejandro Tello Hernández

    2008-07-01

    Full Text Available La conjuntivitis alérgica es una de las causas más comunesde consulta externa en oftalmología y tiene una muy altarelación con las reacciones alérgicas sistémicas. Lafisiopatología de las reacciones de hipersensibilidad noshace entender los cuadros clínicos característicos de estapatología y sus diferentes grados de severidad. Eldiagnostico diferencial es amplio, sin embargo hay clavesdiagnosticas que nos orientan rápidamente al diagnosticocorrecto. El tratamiento se enfoca en las medidasfarmacológicas y no farmacológicas, utilizándolas enconjunto para disminuir la recurrencia del cuadro y prevenirsecuelas visuales.

  2. Superconductivity in Al/Al2O3 interface

    Science.gov (United States)

    Palnichenko, A. V.; Vyaselev, O. M.; Mazilkin, A. A.; Khasanov, S. S.

    2016-06-01

    Metastable superconductivity at Tc ≈ 65 K has been observed in Al foil subjected to special oxidation process, according to the ac magnetic susceptibility and electrical resistance measurements. Comparison of the ac susceptibility and the dc magnetization measurements infers that the superconductivity arises within the interfacial granular layer formed during the oxidation process between metallic aluminum and its oxide.

  3. FTD and ALS: genetic ties that bind.

    Science.gov (United States)

    Orr, Harry T

    2011-10-20

    Curiously, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), seemingly disparate neurodegenerative disorders, can be inherited together. Two groups (DeJesus-Hernandez et al. and Renton et al.) show that the long sought after ALS/FTD mutation on chromosomal region 9p is a hexanucleotide expansion in C90RF72. These studies, plus a study on X-linked ALS/FTD, provide molecular starting points for identifying pathways that link ALS and FTD pathogenesis.

  4. Prólogo al dossier monográfico "La presencia italiana en las Américas"

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Crolla

    2015-01-01

    Full Text Available Pretender elaborar una cartografía de la presencia de los italianos en el continente americano constituye a primera vista una empresa titánica y de resultados siempre aproximativos e incompletos. Pero intentar realizarlo es un desafío que debe asumirse a fin de colocar nuevas piezas en un puzzle inconmensurable, configurado por cantidades de complejas aristas que esperan ser analizadas. La significativa presencia de viajeros e inmigrantes italianos en el continente americano durante los últimos doscientos años -especialmente relevante desde el punto de vista histórico, cultural y humano- permite de forma excepcional estudiar este complejo fenómeno migratorio partiendo del caso concreto del área hispanoamericana y lusófona, tomando para ello como referencia los múltiples ejemplos de interacción entre culturas, al igual que lo que sucedió en América del Norte, donde el arribo de oleadas inmigratorias y los contactos políticos y culturales fueron también sumamente fructíferos.En este sentido, el abordaje de mutuas contaminaciones e interinfluencias a lo largo del tiempo pasa necesariamente por el estudio de fenómenos históricos tan significativos como son las causas y perfiles de la (e(inmigración así como los procesos particulares de inserción en las nuevas territorialidades; la incidencia de la italianidad en corrientes políticas, sociológicas y culturales en los ámbitos de inserción, en las prácticas de lectura y de traducción; o el aporte de creadores italianos y sus descendientes en el campo de la literatura, la filosofía, la ciencia, el arte y la arquitectura. Otro campo de interés es el de la lengua y las investigaciones que se orientan a la detección de italianismos y al estudio de la generación de interlenguas en las variantes del español hispanoamericano, del portugués brasileño, en el inglés norteamericano y en el bilingüismo canadiense. Y todo ello sin descuidar la importancia que la matriz cultural

  5. Drogodependencia y derecho al honor

    OpenAIRE

    Moliner Navarro, Rosa María

    2014-01-01

    Resulta frecuente hoy la divulgación de la drogodependencia de algunos personajes públicos en los medios que se dedican a la información social. Acudiendo a la jurisprudencia más reciente en la materia, el artículo analiza el habitual conflicto entre el derecho al honor y el derecho a la libertad de información; identifica los criterios actualmente vigentes en la protección del derecho al honor y señala el límite que la libertad de información nunca puede traspasar en la revela...

  6. Al-Qaeda Since 911

    OpenAIRE

    Brahimi, Alia

    2012-01-01

    Seconds after smiling at her local MP and shaking his hand, Roshonara Choudhry plunged a knife into his stomach. The attack on Stephen Timms in May 2010 was not the most high profile assault inspired by al- Qaeda, nor was it fatal. It did, however, offer a commentary on the changing nature of the terrorist threat since 9/11, al-Qaeda’s major impact on international relations as well as its major failure, and the intimate, perhaps inevitable, connection between the two.

  7. 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...

  8. ¿COLOMBIA DEBE APOSTARLE AL SOFTWARE LIBRE, AL DE FUENTE ABIERTA O AL PROPIETARIO?

    Directory of Open Access Journals (Sweden)

    Luis Alberto Girón Murillo

    2014-06-01

    Full Text Available Es complejo para gestores y administradores conocer las implicaciones que la adopción de modelos de desarrollo de software tendría para una región. Este artículo ofrece una evaluación de las implicaciones dinámicas que para el desarrollo de software de una región tendría el apostar de forma excluyente al software libre, al software de fuente abierta y al software propietario. Se desarrolló un modelo de simulación en Vensim de la dinámica de sistemas en donde se evaluaron 3 escenarios: uno en donde se adopta de forma excluyente el software libre, uno en donde se adopta el software propietario y uno en donde se adopta el software de fuente abierta. Se ofrecen descripciones y explicaciones de los resultados que sugieren las potencialidades de cada uno de los modelos de desarrollo evaluados.

  9. Un controesempio al Modus Ponens

    Directory of Open Access Journals (Sweden)

    Vann McGee

    2011-11-01

    Full Text Available La traduzione dell’articolo è stata resa possibile grazie al consenso dell’autore e del Journal of Philosophy. Riferimenti originali: Vann McGee (1985: “A Counterexample to Modus Ponens”, Journal of Philosophy, Vol. 82, No. 9 (Sep. 1985, pp. 462-47. [N.d.T.

  10. Der Nutzer als besserer Fachreferent?

    Directory of Open Access Journals (Sweden)

    Robert Scheuble

    2014-12-01

    Full Text Available Am 9. Juli 2014 veranstaltete der VDB-Regionalverband Südwest in Kooperation mit der Deutschen Nationalbibliothek in Frankfurt am Main eine Fortbildungsveranstaltung zum Thema „Der Nutzer als besserer Fachreferent?”, die sich mit Formen von und Erfahrungen mit nutzergesteuerter Erwerbung (PDA in wissenschaftlichen Bibliotheken beschäftigte.

  11. Kringloop als basis van bedrijfsvoering

    NARCIS (Netherlands)

    Linde, van der A.

    2007-01-01

    Gerard Keurentjes bekijkt zijn bedrijf als kringloop waarin grond en koeien de spil zijn. Het gebruik van microbiotica in plaats van antibiotica past daarin perfect. Een microbioticum bestaat uit een mengsel van acht kruiden opgelost in alcohol. Onderzoek toont aan dat het de productie van witte blo

  12. Al Zubarah - eine vergessene Legende

    DEFF Research Database (Denmark)

    Kinzel, Moritz

    2014-01-01

    Jahre später auf einem Sechstel der ursprünglichen Siedlungsfläche wiedererrichtet und dann im ausgehenden 19. Jahrhundert / beginnenden 20. Jahrhundert endgültig aufgeben. Die Stadt lebt als Legende im Bewusstsein der katarischen Bevölkerung, doch der Name wird heute nicht mit der Stadtanlage sondern...

  13. MOOCs; vanwaar al die ophef?

    NARCIS (Netherlands)

    Henderikx, Maartje; Kreijns, Karel

    2016-01-01

    MOOCs; vanwaar die ophef? Het nog maar zeer recente fenomeen MOOCs (massive open online courses) heeft zich in korte tijd al een onwrikbare positie weten in te nemen in het open online onderwijs. De hype rondom deze nieuwe manier van onderwijs geven bereikte zijn hoogtepunt in 2012, dat prompt werd

  14. First principles calculation of ac conductance for Al-BDT-Al and Al-Cn-Al systems

    Directory of Open Access Journals (Sweden)

    Jia-Ning Zhuang

    2011-12-01

    Full Text Available We perform first-principles calculation to investigate the dynamic conductance of atomic wires of the benzenedithiol (BDT as well as carbon chains with different length in contact with two Al(100 electrodes (Al-Cn-Al. Our calculation is based on the combination of the non-equilibrium Green's function and the density functional theory. For ac conductance, there are two theories that ensures the current conservation: (1. the global formula which is a phenomenological theory that partitions the total displacement current into each leads so that the current is conserved.(2. the local formula which is a microscopic theory that includes Coulomb interaction explicitly so that the current is conserved automatically. In this work, we use the local formula to calculate the dynamic conductance, especially the emittance. We give a detailed comparison and analysis for the results obtained from two theories. Our numerical results show that the global formula overestimates the emittance by two orders of magnitude. We also obtain an inequality showing that the emittance from global formula is greater than that from local formula for real atomic structures. For Al-Cn-Al structures, the oscillatory behavior as the number of carbon chain N varies from even to odd remains unchanged when local formula is used. However, the prediction of local formula gives rise to opposite response when N is odd (inductive-like as compared with that of global formula. Therefore, one should use the local formula for an accurate description of ac transport in nanoscale structures. In addition, the ‘size effect’ of the ac emittance is analyzed and can be understood by the kinetic inductance. Since numerical calculation using the global formula can be performed in orbital space while the local formula can only be used in real space, our numerical results indicate that the calculation using the local formula is extremely computational demanding.

  15. Personalidad y tolerancia al dolor

    Directory of Open Access Journals (Sweden)

    JESÚS M.ª CARRILLO

    2005-01-01

    Full Text Available Se examina la relación de algunas variables de personalidad -EPQ-A (Eysenck y Eysenck, 1975, NEO-PI (McCrae y Costa, 1988 y STA -personalidad esquizotípica- y STB -personalidad límite-, de Claridge y Broks (1984, con la tolerancia al dolor experimental inducido mediante agua fría (cold pressor test, según el procedimiento de Staats, Heckmat y Staats (1998 en una muestra filtrada mediante un cuestionario sobre dolor crónico, dolores de cabeza, de espalda, artritis, síndrome de Raynaud, y personas bajo medicación. La tolerancia al dolor experimental se evaluó mediante el Umbral del dolor (tiempo en segundos desde la introducción de la mano en el agua hasta el primer informe de dolor, Mantenimiento del dolor (duración en segundos de la inmersión de la mano desde la aparición del umbral hasta su retirada y Tolerancia al dolor (duración total en segundos de la inmersión de la mano desde su introducción hasta su retirada. Un análisis correlacional, factorial y de regresión por pasos mostraron un efecto cruzado entre medidas de ansiedad (tolerancia negativa al dolor y psicoticismo, siendo psicoticismo junto con control emocional predictores de tolerancia positiva al dolor. En cuanto a psicoticismo, parece que son sus elementos de naturaleza paranoide y de "dureza" los que afectan a una percepción atenuada del dolor.

  16. Comportamiento a fatiga del vástago de una prótesis para cadera al caminar//Fatigue behavior stem hip prosthesis for walking

    Directory of Open Access Journals (Sweden)

    Ángel Martínez-Delfín

    2014-01-01

    Full Text Available La prótesis de cadera consiste en sustituir la parte superior fracturada del fémur por una pieza de material biocompatible. Debido a las cargas aleatorias que sobre esta prótesis actúan al caminar la persona injertada, surge la fatiga sobre la prótesis. En este trabajo se realiza el cálculo a fatiga del vástago de una prótesis de caderas fabricada con acero inoxidable austenítico AISI 316L GrQ y de uso actual. Para ellose emplea el método de los elementos finitos, considerando la compleja geometría del vástago, el material y las cargas variables resultantes del caminar de la persona con la prótesis artificial colocada. Se calcula el daño a fatiga que estas cargas provocan en la misma así como el número de pasos que pueden darse, garantizándose una larga vida útil de la prótesis por este concepto de resistencia.Palabras claves: fatiga, prótesis de cadera, ciclo, daño, elementos finitos.______________________________________________________________________________AbstractThe hip prosthesis consists in substituting the fractured femur part by a piece of biocompatible material. Because the random character of loads acting over this prosthesis while person walk, crop up the fatigue on the prosthesis. The fatigue behavior of austenitic stainless steel hips prosthesis is studied in this article. The method of finite elements is used, considering the complex geometry of the part, the material and the variable acting loads, as results of steps of walking person. The fatigue damages are calculated as well as the number of steps that can be given, guarantying a long life of the prosthesis for fatigue resistance concept.Key words: fatigue, hip prosthesis, cycle, damage, finite elements.

  17. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

    Science.gov (United States)

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-21

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  18. LA NEGOCIACIÓN COOPERATIVA, UNA APROXIMACIÓN AL MODELO HARVARD DE NEGOCIACIÓN

    Directory of Open Access Journals (Sweden)

    Darío Parra Sepúlveda

    2012-12-01

    Full Text Available En el presente trabajo se pretende dar una descripción genérica sobre aquellos conceptos básicos que compondrían la denominada teoría de la negociación cooperativa o también llamada modelo Harvard de negociación, la cual, en términos simples, plantea que ambas partes negociantes vean satisfechos sus intereses, aportando una visión que viene a complementar el modelo clásico de negociación distributiva en el que –por definición– sólo una de las partes ha de lograr beneficios a raíz de las pérdidas que sufre la contraria.

  19. La solidaridad de mercado y sus sujetos en el capitalismo de consumo: un análisis del discurso neoliberal sobre piezas de publicidad en Chile A Solidariedade do mercado e seus sujeitos no capitalismo de consumo: uma análise do discurso neoliberal a partir de peças publicitárias no Chile The market solidarity and its subjects in the capitalist consumption: an analysis of the neoliberal discourse on ads in Chile

    Directory of Open Access Journals (Sweden)

    José Antonio Román Brugnoli

    2010-08-01

    Full Text Available El carácter neoliberal del proceso de modernización y la instalación de un modelo de sociedad de consumo ha implicado un cambio en la norma social del vínculo social, desde una solidaridad mutualista a otra altruista, y en los sujetos de ese vínculo. En este contexto es pertinente indagar la relación entre esta nueva norma de solidaridad y las formas de subjetivación correspondientes. Con ese objetivo se realizó un análisis de discurso desde el modelo de la psicología crítica de Parker (1990,1992 sobre doce piezas publicitarias de ayuda o promoción de la solidaridad, emitidas por instituciones con fines de lucro. En los resultados se describe la solidaridad neoliberal y los tipos de sujetos solidarios que pueden realizarse a través del consumo.A natureza neoliberal do processo de modernização e a instalação de um modelo de sociedade de consumo tem implicado em uma mudança na norma social de laços sociais, de uma solidariedade mutualista a altruísta, e nos sujeitos desse vínculo. Nesse contexto, é relevante investigar a relação entre esta nova norma de solidariedade e formas de subjetividade envolvidas. Com esse objetivo, foi realizada uma análise do discurso a partir do modelo da psicologia crítica de Parker (1990.1992 de doze peças publicitárias de ajuda ou promoção da solidariedade, lançadas por instituições com fins lucrativos. Nos resultados são descritos a solidariedade neoliberal e os tipos de sujeitos solidários que podem realiza-se através do consumo.The neoliberal nature of the process of modernization and the installation of a consumer society model has involved a change in social norms of social ties from a mutual solidarity to an altruist notion of solidarity. Also, it has introduced changes in the subjectivity. In this context it is relevant to investigate the relationship between this new norm of solidarity and forms of subjectivity involved. A discourse analysis was conducted from a model of

  20. Effect of interface geometry on electron tunnelling in Al/Al2O3/Al junctions

    Science.gov (United States)

    Koberidze, M.; Feshchenko, A. V.; Puska, M. J.; Nieminen, R. M.; Pekola, J. P.

    2016-04-01

    We investigate how different interface geometries of an Al/Al2O3 junction, a common component of modern tunnel devices, affect electron transport through the tunnel barrier. We study six distinct Al/Al2O3 interfaces which differ in stacking sequences of the metal and the oxide surface atoms and the oxide termination. To construct model potential barrier profiles for each examined geometry, we rely on first-principles density-functional theory (DFT) calculations for the barrier heights and the shapes of the interface regions as well as on experimental data for the barrier widths. We show that even tiny variations in the atomic arrangement at the interface cause significant changes in the tunnel barrier parameters and, consequently, in electron transport properties. Especially, we find that variations in the crucial barrier heights and widths can be as large as 2 eV and 5 Å, respectively. Finally, to gain information about the average properties of the measured junction, we fit the conductance calculated within the Wentzel-Kramers-Brillouin approximation to the experimental data and interpret the fit parameters with the help of the DFT results.

  1. ATSAR THARIQAH AL-QIRA'AH AL-MUTAKARRIRAH FI MAHARAH AL-KITABAH

    Directory of Open Access Journals (Sweden)

    Rihlah

    2016-06-01

    Full Text Available This study aimed to reveal the students' writing skill, namely dictation (Imlâ’ and to analyze the use of the repeated reading technique in learning Qirâ'ah Jahriyyah, as well as to determine the effect of the use of al-Qirâ'ah al-Mutakarrirah technique on the students' skills in writing dictation. This method was used to improve students’ reading fluency at the beginners’ level, which was popularized by Samuel in 1979. This research used the experimental method through pretest and posttest control group design. The samples of the research were 44 students consisted of 22 students the experimental class and 22 students of the control class. The analysis of the data applied t-test. The results showed that the use of was significant on the students' writing skill in dictation. It was based on the tcount, 2.64, and ttable, 2.02, at the significance level of 5%. The al-Qirâ'ah al-Mutakarrirah technique was thus effectively used to develop the beginner-leveled students’ writing skill, especially dictation.

  2. Al-Ḥaqīqah al-Muwāfaqah li al-Sharī‘ah: al-Taṣāluḥ bayn al-Taṣawuf wa al-Sharī‘ah bi Nusantara fi al-Qarn al-Sādis ‘Ashr al-Mīlādī

    OpenAIRE

    Iin Suryaningsih

    2013-01-01

    This article discusses the reinterpretation of waḥdat al-wujūd doctrine among Muslims of the archipelago, using the sharī‘ah approach in Sufism as suggested by Al-Būrhanpūrī (d.1620) in his work al-Haqīqah al-Muwāfaqah li al-Sharī‘ah. This work is one of the commentaries (sharḥ) from al-Tuḥfah al-Mursalah ila rūḥ al-Nabī SAW, that invited much debate among Muslims of the archipelago. Al-Būrhanpūrī’s detailed interpretation of waḥdat al-wujūd doctrine proved that the essence of the concep...

  3. Al-Anon and recovery.

    Science.gov (United States)

    Cermak, T L

    1989-01-01

    The history of Al-Anon and its current demographics are reviewed. In order to understand 12-step recovery and psychotherapy for family members of alcoholics, the concept of codependence is defined with a set of diagnostic criteria consistent with the DSM-III-R definition of personality traits and disorders. At the core of codependence are denial and an unrealistic relationship to willpower. The therapeutic implications of considering codependence as a personality disorder are explored, as are the characteristics that make codependence unique among personality disorders: the central role of denial and the existence of a self-help organization to facilitate recovery. The dynamics of working the 12 steps on codependent characteristics are outlined. A synergistic relationship between psychotherapy and the 12 steps is described. Special attention is given the emergence of Al-Anon adult children of alcoholic meetings, and the future of codependence is discussed.

  4. Relativity and Al^+ Optical Clocks

    Science.gov (United States)

    Chou, Chin-Wen; Hume, David B.; Wineland, David J.; Rosenband, Till

    2010-03-01

    We have constructed an optical clock based on quantum logic spectroscopy of an Al+ ion that has a fractional frequency inaccuracy of 8.6x10-18. The frequency of the ^1S0^3P0 clock transition is compared to that of a previously constructed Al^+ optical clock with a statistical measurement uncertainty of 7.0x10-18. The two clocks exhibit a relative stability of 2.8x10-15&-1/2circ;, and a fractional frequency difference of -1.8x10-17, consistent with the accuracy limit of the older clock. By comparing the frequencies of the clocks, we have observed relativistic effects, such as time dilation due to velocities less than 10 m/s and the gravitational red shift from a 0.33 m height change of one of the clocks.

  5. Wear behaviour of Al 261

    Directory of Open Access Journals (Sweden)

    N. Mathan Kumar

    2016-03-01

    Full Text Available Al 2618 matrix material was mixed with the Silicon Nitride (Si3N4, Aluminium Nitride (AlN and Zirconium Boride (ZrB2 reinforced particles. AMC was synthesized successfully by the stir casting method with the various X-wt.% of reinforcements (X = 0,2,4,6,8. Tribological behaviour was studied in this composite with various temperature conditions. The working conditions were Temperature (°C, Load (N, Velocity (m/s and Sliding Distances (m. Before wear testing the mechanical behaviour has been analysed. EDAX was confirmed by the matrix material composition. The Al 2618 alloy and the reinforcement mixers were confirmed by the X-ray Diffraction analysis. Wear rate (mm3/m, Wear resistance (m/mm3, Specific Wear rate (m/Nm and Co-efficient of friction (μ were analysed with various conditions. The worn surfaces were analysed before and after wear testing by Scanning Electron Microscope (SEM. Influence of process parameters and Percentage of contribution were analysed by Taguchi and Analysis of Variance (ANOVA methods. Genetic Algorithm (GA was adopted for optimizing the best and mean of the wear rate and to identify the exact influence of input parameters.

  6. Vormundschaftsrecht als Grundlage politischer Herrschaft

    Directory of Open Access Journals (Sweden)

    Arne Duncker

    2006-07-01

    Full Text Available In ihrer beachtlichen und sehr gewissenhaft dokumentierten Arbeit über vormundschaftliche Regentschaften im 16. und 17. Jahrhundert beschreibt Pauline Puppel unter ausführlichem Bezug auf zeitgenössische Literatur und Archivalien sowohl die allgemeine Rechtslage im damaligen Reich als auch die Anwendungsfälle in Hessen, wo zwischen 1500 und 1700 insgesamt viermal eine Landgräfin als Vormünderin des Fürsten zur Regentin ihres Landes wurde. Dies steht exemplarisch für eine bereits in der Frühen Neuzeit mögliche und nicht einmal ganz seltene Form politischer Frauenherrschaft, die bisher oft nicht hinreichend gewürdigt wurde. Puppels Untersuchung ist in zwei Hauptteile gegliedert. Der erste Teil (Das juristische Regelwerk“, S. 34-143 behandelt die zeitgenössischen Rahmenbedingungen der durch Frauen ausgeübten Vormundschaft und Regentschaft. Der zweite Abschnitt („Die Landgräfinnen von Hessen als Regentinnen“, S. 144-307 befasst sich mit der Ausfüllung dieser Regeln durch konkrete Fallbeispiele in Gestalt von Leben und Regentschaft der regierenden Landgräfinnen von Hessen.

  7. Al Margen de las Cooperativas

    Directory of Open Access Journals (Sweden)

    Gutiérrez Estrada Julio

    1941-04-01

    Full Text Available El sistema Cooperativista, propiamente hablando, no viene a constituir una doctrina económica, es más bien una práctica, un modo de proceder en provecho de determinada agrupación de individuos que se asocian para defenderse de la usura del comercio y del intermediarismo parasitario. "El movimiento cooperativo es tan viejo como la revolución industrial, y ha crecido paralelamente a ella, podría decirse como una protesta en contra del sistema capitalista industrial. Generalmente se considera que tres principios fundamentales determinan su carácter distintivo. 1-Se esfuerza por dar "servido al costo" a sus miembros antes que beneficiarse del negocio con el público en general. El servicio de un grupo organizado se considera como un medio para obtener el máximum de eficacia con mínimo de desperdicio. 2-Insiste en que los beneficios pecuniarios se distribuyan al miembro como productor, después de deducir solamente el interés del capital al tipo que compite, y los salarios y jornales de los trabajadores. 3-Mantiene el control democrático del negocio por todos los participantes en él".

  8. Namadhij Min al-Fikr al-Mali fi al-Islam: Waraqah Ma’lumat Asasiyyah

    Directory of Open Access Journals (Sweden)

    Mustafa Dasuki Kasabah

    2009-03-01

    Full Text Available The renaissance of Islam in various countries has become new phenomenon in the global economy. At the same time it also become the challenge for the Western capitalism and Eastern socialism. This resurrection together with revised ideology and economic system is considered as the strategic solution. Frankly, Islam is the religion which has brought back the core of economy to its position proportionally. In order to get concrete and clear idea on Islamic economy, here the writer presents five books written by Muslim scholars, classic as well as contemporary. The first is Kitab al-Amwal written by Abu Ubaid bin Salam, according to Khalil Harras this book is considered as the best and the most comprehensive book of Islamic economy. The second is Kitab Al-Ahkam al-Sultaniyyah written by Imam Mawardi. The third is Al-Fikr al-Mali written by Ibnu Khaldun, which has high scientific authority from other books, it is systematic as well as contextual. The fourth is al-Iradat al-‘Ammah li al-Daulah al-Islamiyyah fi Sadr al-Islam wa Tatbiqatuha al-Mu’asirah written by Monzer Kahf. The fifth is Al-Nafaqat al-‘Ammah fi Al-Islam: Dirasah Muqaranah written by Yusuf Ibrahim Yusuf. The first three authors are classics and the rest are contemporary.

  9. 77 FR 73732 - In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al...

    Science.gov (United States)

    2012-12-11

    ... Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al-Jihad, aka The Monotheism and Jihad Group, aka The al-Zarqawi Network, aka al-Tawhid, aka Tanzim Qa`idat al-Jihad fi Bilad al-Rafidayn, aka The Organization of al-Jihad's Base of Operations in Iraq, aka al-Qaida of Jihad in Iraq, aka al-Qaida in Iraq,...

  10. Armaflex in Burj al Arab; Armaflex im Burj al Arab

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, B.

    2003-07-01

    This article describes the Burj al Arab in Dubai, the unique seven-star high-rise hotel. The construction of the hotel, that is built on 250 piles driven into the sand of an artificial island in the Persian Gulf, is described. In particular, various special materials used in the building are described, as are the luxurious fittings and furnishings of the hotel. The cooling and air-conditioning installations that are necessary as a result of the desert climate of Dubai are described and the use of 'Armaflex' elastomer insulating material for the insulation of refrigeration machines and cold-water piping is discussed.

  11. Microstructure of interaction interface between Al-Si, Zn-Al alloys and Al2O3p/6061Al composite

    Institute of Scientific and Technical Information of China (English)

    许志武; 闫久春; 吕世雄; 杨士勤

    2004-01-01

    Interaction behaviors between Al-Si, Zn-AI alloys and Al2O3p/6061AI composite at different heating temperatures were investigated. It is found that Al2O3p/6061Al composite can be wetted well by AlSi-1, AlSi-4 and Zn-Al alloys and an interaction layer forms between the alloy and composite during interaction. Little Al-Si alloys remain on the surface when they fully wet the composite and Si element in Al-Si alloy diffuses into composite entirely and assembles in the composite near the interface of Al-Si alloy/composite to form a Si-rich zone. The microstructure in interaction layer with Si penetration is still dense. Much more residual Zn-Al alloy exists on the surface of composite when it wets the composite, and porosities appear at the interface of Zn-Al alloy/composite. The penetration of elements Zn, Cu of Zn-Al alloy into composite leads to the generation of shrinkage cavities in the interaction layer and makes the microstructure of Al2 O3p/6061A1 composite loose.

  12. Investigations of Al-Dalang and Al-Hawashat meteorites

    Science.gov (United States)

    Gismelseed, A. M.; Abdallah, S. B.; Al-Rawas, A. D.; Al-Mabsali, F. N.; Widatallah, H. M.; Elzain, M. E.; Yousif, A. A.; Ericsson, T.; Annersten, H.

    2016-12-01

    Mössbauer spectroscopy, X-ray diffraction (XRD) measurements, and electron microprobe analysis (EMPA) have been performed on two meteorites named Al-Dalang and Al-Hawashat after identifying their falling sites in the Western region of Sudan. These two meteorites are ordinary chondrites with similar mineralogy. XRD and EMPA show that the two specimens consist of primary olivine, ortho-pyroxene and later crystallising clino-pyroxene as reaction rims against plagioclase. Fe-metal phases are dominated by kamacite (≈6 wt.% Ni) and minor amounts of tetrataenite (≈52 wt.% Ni). Troilite (FeS) and alabandite (MnS) are optically observed as sulphide phases. The Mössbauer measurements at 295 and 78 K are in agreement with the above characterizations, showing at least two paramagnetic doublets which are assigned to olivine and pyroxene and magnetic sextets assigned to kamacite (hyperfine field ≈33.5 T) and troilite FeS (hyperfine field ≈31 T).

  13. Electrical conductivity of (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effects of contents of AlF3 and Al2O3,and temperature on electrical conductivity of (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 were studied by continuously varying cell constant (CVCC) technique.The results show that the conductivities of melts increase with the increase of temperature,but by different extents.Every increasing 10 ℃ results in an increase of 1.85×10-2,1.86×10-2,1.89×10-2 and 2.20×10-2 S/cm in conductivity for the (Na3AlF6-40%K3AlF6)-AlF3 melts containing 0%,20%,24%,and 30% AlF3,respectively.An increase of every 10 ℃ in temperature results an increase about 1.89×10-2,1.94×10-2,1.95×10-2,1.99×10-2 and 2.10×10-2 S/cm for (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts containing 0%,1%,2%,3% and 4% A12O3,respectively.The activation energy of conductance was calculated based on Arrhenius equation.Every increasing 1% of AlF3 results in a decrease of 0.019 and 0.020 S/cm in conductivity for (Na3AlF6-40%K3AlF6)-AIF3 melts at 900 and 1 000 ℃,respectively.Every increase of 1% Al2O3 results in a decrease of 0.07 S/cm in conductivity for (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts.The activation energy of conductance increases with the increase in content of AlF3 and Al2O3.

  14. United modification of Al-24Si alloy by Al-P and Al-Ti-C master alloys

    Institute of Scientific and Technical Information of China (English)

    韩延峰; 刘相法; 王海梅; 王振卿; 边秀房; 张均艳

    2003-01-01

    The modification effect of a new type of Al-P master alloy on Al-24Si alloys was investigated. It is foundthat excellent modification effect can be obtained by the addition of this new type of A1-P master alloy into Al-24Simelt and the average primary Si grain size is decreased below 47 μm from original 225 μm. It is also found that theTiC particles in the melt coming from Al8Ti2C can improve the modification effect of the Al-P master alloy. Whenthe content of TiC particles in the Al-24Si melt is 0.03 %, the improvement reaches the maximum and keeps steadywith increasing content of TiC particles. Modification effect occurs at 50 min after the addition of the Al-P master al-loy and TiC particles, and keeps stable with prolonging holding time.

  15. Kurzwortbildungen als Merkmal der Deutschenrechtssprache

    Directory of Open Access Journals (Sweden)

    Ljubica Kordić

    2013-12-01

    Full Text Available In deutscher Rechtssprache kommen häufig die Nominalkomposita vor, die auf eineim Vergleich mit der Gemeinsprache ungewöhnliche Weise gebildet werden. Diese Wortbildungsform wird in deutschen Grammatiken unterschiedlich bestimmt: als Reduktion, Kurzwortbildung, Kontraktion bzw. Klammerform. Dieser Wortbildungstypkann mit dem Kompositum Mietblock illustriert werden, das durch Verkürzung aus Miet(wohnungsblock entstanden ist. Im Kroatischen, wo Komposition als Wortbildungstyp relativ schwach vertreten ist, ist die Bildung solcher Komposita theoretisch nur angedeutet. Da die Komposita dieses Bildungstyps in deutschen Rechtstexten stark vertreten sind, ist das Ziel dieses Beitrags, auf ihre Gebräuchlichkeit als ein für deutsche Rechtstexte charakteristisches Merkmal hinzuweisen. In der Einleitung befasstsich die Autorin mit der Begriffsbestimmung, der theoretischen Determinierung undder Abgrenzung dieser Kompositionsart von anderen Sonderfällen. Den Hauptteil der Arbeit bildet die Untersuchung der Kurzwortbildungen (Klammerformen, Reduktionen, Verschmelzungen, die dem geltenden deutschen Strafgesetzbuch von 2009 entnommensind, und ihrer kroatischen Entsprechungen. Der Beitrag hat die Aufgabe, auf Grund der gesammelten Belege die Häufigkeit und die Bildungsmuster der Komposita dieses Typs in deutscher Rechtssprache zu bestimmen und durch semantische Transformationsmuster ihren Informationswert in Bezug auf die Konstituenten festzustellen, aus denen sie gebildet wurden. Es wird auch untersucht, welche Bildungstypen ihrekroatischen Äquivalente aufweisen und ob es irgendwelche Unterschiede in ihrem informativen Wert gibt. Die Autorin bedient sich der Methode der Datensammlung, der qualitativen semantischen Analyse der Belege nach den Transformationsmodellen von Fleischer und Barz und der Synthese der Resultate. Die Resultate dieser Untersuchung sollten einen Beitrag zur Erforschung der der Rechtslinguistik im allgemeinen leisten, inbesondere im

  16. Reply to Pachai et al.

    Science.gov (United States)

    Harrison, William J; Bex, Peter J

    2016-05-01

    Peripheral vision is fundamentally limited by the spacing between objects. When asked to report a target's identity, observers make erroneous reports that sometimes match the identity of a nearby distractor and sometimes match a combination of target and distractor features. The classification of these errors has previously been used to support competing 'substitution' [1] or 'averaging' [2] models of the phenomenon known as 'visual crowding'. We recently proposed a single model in which both classes of error occur because observers make their reports by sampling from a biologically-plausible population of weighted responses within a region of space around the target [3]. It is critical to note that there is no probabilistic substitution or averaging process in our model; instead, we argue that neither substitution nor averaging occur, but that these are misclassifications of the distribution of reports that emerge when a population response distribution is sampled. This is a fundamentally different way of thinking about crowding, and on this basis we claim to have provided a mechanism unifying categorically distinct perceptual errors. Our goal was not to model all crowding phenomena, such as the release from crowding when target and flanks differ in color or depth [4]. Pachai et al.[5] have suggested that our model is not unifying because it inaccurately predicts perceptual performance for a particular stimulus. Although we agree that our model does not predict their data, this specific demonstration overlooks the critical aspect of the model: perceptual reports are drawn from a weighted population code. We show that Pachai et al.'s [5] own data actually provide evidence for the population code we have described [3], and we suggest a biologically-plausible analysis of their stimuli that provides a computational basis for their 'grouping' account of crowding.

  17. A melancolia em Al Berto

    OpenAIRE

    Camila Emanuele Martins de Souza

    2015-01-01

    Este trabalho objetiva estudar, sob a perspectiva da melancolia, os livros Salsugem (1984) e Horto de Incêndio (1997), de Al Berto. O autor português produz escritos em que a temática da melancolia atravessa a palavra, o que justifica o debruçar-se sobre as construções textuais da poética albertiana, a fim de traçar-lhe novas possibilidades de leitura por esse ângulo. Para isso, com o intuito de compreender o discurso melancólico segue-se o embasamento teórico: de Klibansky, Panosfsky e Saxl ...

  18. Alí Caro, alarife

    OpenAIRE

    2009-01-01

    Quizá el más sobresaliente sea el de Alí Caro, un alarife que a finales del siglo xv proyectó y dirigió la construcción del castillo de Coca, la obra más insigne de la arquitectura militar mudéjar del siglo xv castellano. Efectivamente, encontramos que hacia 1486 fue reclamado por don Alonso FonsecaAvellaneda, señor de las villas de Coca y Alaejos, para levantar un impresionante castillo -que, a la vez, cumpliría las funciones de palacio nobiliar- en Coca, con la ayuda de sus hermanos Yuc;...

  19. La heredad junto al llanto

    Directory of Open Access Journals (Sweden)

    Javier Arias Ramírez

    1962-11-01

    Full Text Available En "La heredad junto al llanto", Carlos Palacio La verde canta todo lo elemental y simple con sobriedad y elegancia que dan mérito a su poesía. Por eso consideramos un acierto de sus editores el divulgar la obra de este joven poeta, que como dice en su introducción René Uribe Ferrer, no es conocido porque ha rehuido casi sistemáticamente la publicidad, lo cual me asegura que en este proceder hay una grande honestidad intelectual, una verdadera personalidad poética.

  20. Personalidad y tolerancia al dolor

    OpenAIRE

    JESÚS M.ª CARRILLO; SUSANA COLLADO; NIEVES ROJO

    2005-01-01

    Se examina la relación de algunas variables de personalidad -EPQ-A (Eysenck y Eysenck, 1975), NEO-PI (McCrae y Costa, 1988) y STA -personalidad esquizotípica- y STB -personalidad límite-, de Claridge y Broks (1984), con la tolerancia al dolor experimental inducido mediante agua fría (cold pressor test), según el procedimiento de Staats, Heckmat y Staats (1998) en una muestra filtrada mediante un cuestionario sobre dolor crónico, dolores de cabeza, de espalda, artritis, síndrome de Raynaud, y ...

  1. Gettysburg: Monumento al mundo libre

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1961-12-01

    Full Text Available En el verano del año 1958 fui invitado, por las autoridades de la Universidad de Arizona, en Tucson, a la colocación de la primera piedra de su futuro taller, construido para favorecer el desarrollo técnico del Estado. Varios alcaldes y ministros presenciaron la ceremonia, que fue muy interesante, y uno de los periodistas presentes, John Riddick, del "Tucson Daily Citizen", invitó cordialmente, a mi esposa y a mí, a atravesar, al día siguiente, la frontera mejicana, que cruzaba un vasto desierto.

  2. Al-Ḥaqīqah al-Muwāfaqah li al-Sharī‘ah: al-Taṣāluḥ bayn al-Taṣawuf wa al-Sharī‘ah bi Nusantara fi al-Qarn al-Sādis ‘Ashr al-Mīlādī

    Directory of Open Access Journals (Sweden)

    Iin Suryaningsih

    2013-04-01

    Full Text Available This article discusses the reinterpretation of waḥdat al-wujūd doctrine among Muslims of the archipelago, using the sharī‘ah approach in Sufism as suggested by Al-Būrhanpūrī (d.1620 in his work al-Haqīqah al-Muwāfaqah li al-Sharī‘ah. This work is one of the commentaries (sharḥ from al-Tuḥfah al-Mursalah ila rūḥ al-Nabī SAW, that invited much debate among Muslims of the archipelago. Al-Būrhanpūrī’s detailed interpretation of waḥdat al-wujūd doctrine proved that the essence of the concept did not contradict the basic principles of Islam as contained in the Quran and Hadith. Al-Būrhanpūrī  interpreted the concept through explanations that adjusted to the audience’s competence, utilizing oral language carefully in revealing spiritual experience not easily explained, as well as employing the bases of sharī‘ah. Al-Haqīqah al-Muwāfaqah has provided the information about the explanations of interpretation tradition among the archipelago sufis.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v20i1.350 

  3. Betaalde arbeid als verdringer van vrijwilligerswerk? Overbelasting als mogelijke verklaring

    Directory of Open Access Journals (Sweden)

    Angela Kok-Van Meer

    2014-06-01

    Full Text Available Do paid work activities displace volunteering? A potential explanation from role overload theoryRecent changes in Dutch society might lead to a shortage of volunteers. On the one hand, the demand for volunteers is increasing: in the social welfare domain because of governmental austerity policies and in other domains such as sports because of the higher supervision intensity of activities. On the other hand, the supply of volunteers is likely to decrease as more and more women and older workers are active in the labor market, which reduces the time that is available for volunteering. Role overload theory would suggest that the increasing labor participation rate of certain categories of workers goes along with a decline of participation in voluntary work. The secondary data analysis shows that various role loads (work, care for children living at home are associated with differences in participation in voluntary work. However, while a higher number of contractual work hours and hours spent on work-related training are negatively associated with volunteer work, care for children living at home is positively associated with volunteering. These results provide only limited support for role overload theory.Betaalde arbeid als verdringer van vrijwilligerswerk? Overbelasting als mogelijke verklaringDe afgelopen jaren hebben zich enkele maatschappelijke veranderingen voorgedaan, die wellicht tot schaarste op de Nederlandse vrijwilligersmarkt zouden kunnen leiden. Enerzijds neemt de vraag naar vrijwilligers toe doordat subsidieregelingen versoberen (bijvoorbeeld in zorg en welzijn en de begeleidingsintensiteit in bepaalde organisaties stijgt (bijvoorbeeld in sport. Anderzijds neemt het aanbod van vrijwilligers af doordat vrouwen en ouderen meer en langer op de arbeidsmarkt actief zijn, waardoor minder tijd beschikbaar is voor vrijwilligerswerk. In dit artikel wordt aan de hand van de role overload theorie nagegaan of het al dan niet deelnemen aan

  4. Ti_3AlC_2-Al_2O_3-TiAl_3 composite fabricated by reactive melt infiltration

    Institute of Scientific and Technical Information of China (English)

    HE Shan-shan; YIN Xiao-wei; ZHANG Li-tong; LI Xiang-ming; CHENG Lai-fei

    2009-01-01

    Porous preforms were fabricated by cold-pressing process using powder mixture of TiC, TiO_2 and dextrin. After pyrolysis and sintering, Al melt was infiltrated into the porous preforms, leading to the formation of Ti_3AlC_2-Al_2O_3-TiAl_3 composite. Effects of cold-pressing pressure of preforms on microstructures and mechanical properties of the composites were studied. Synthesis mechanism and toughening mechanism of composite were also analyzed. The results shows that TiO_2 is reduced into Ti_2O_3 by carbon, the decomposition product of dextrin, which causes the spontaneous infiltration of Al melt into TiC/Ti_2O_3 preform. Then, Ti_3AlC_2-Al_2O_3-TiAl_3 composite is in-situ formed from the simultaneous reaction of Al melt with TiC and Ti_2O_3. With the increase of cold-pressing pressure from 10 MPa to 40 MPa, the pore size distribution of the preforms becomes increasingly uniform after pre-sintering, which results in the reduction of defects, and the decrease of property discrepancy of composites. Nano-laminated Ti_3AlC_2 grains and Al_2O_3 particles make the fracture toughness of TiAl_3 increase remarkably by various toughening mechanisms including stress-induced microcrack, crack deflection and crack bridging.

  5. Ce对Al-Si-Cu合金中α(Al)-Al2Cu共晶形貌的影响%Effect of Ce on morphology ofα(Al)-Al2Cu eutectic in Al-Si-Cu alloy

    Institute of Scientific and Technical Information of China (English)

    Maja VONINA; Joef MEDVED; Tonica BONINA; Franc ZUPANI

    2014-01-01

    The effect of Ce addition on the morphology of the α(Al)-Al2Cu eutectic in Al-Si-Cu alloy was investigated using thermal analysis, light microscopy, scanning electron microscopy, focused ion beam and energy dispersive analysis. The results show that the eutectic α(Al)-Al2Cu forms within small space between dendrites, silicon and AlSiFeMn plates. Eutectic Al2Cu is not lamellar but degenerated. However, Al2Cu in Ce-modified alloys is more compact. Ce partially dissolves in Al2Cu, which is a viable reason for the formation of coarser Al2Cu. The addition of Ce also increases the microhardness of theα(Al)-Al2Cu eutectic by almost 10%compared with the basic Al-Si-Cu alloy.%采用热分析、光学显微镜技术、扫描电镜技术、聚焦离子束和能量色散谱分析方法研究Ce对Al-Si-Cu合金中α(Al)-Al2Cu共晶形貌的影响。结果表明,在枝晶、硅和AlSiFeMn之间较小空间内形成了α(Al)-Al2Cu共晶。Al2Cu为非层状的不规则共晶组织。Al2Cu在经Ce改性的合金中更加致密。部分Ce溶解于Al2Cu中,这是粗晶Al2Cu形成的原因。与基体Al-Si-Cu合金相比,Ce的加入能使α(Al)-Al2Cu共晶合金的显微硬度提高约10%。

  6. con bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Adriana Mora Antó

    2005-01-01

    Full Text Available Esta investigación dio cuenta de la relación entre el estilo de funcionamiento familiar, los patrones de crianza y las edades de desarrollo evolutivo en niños, nacidos con bajo peso. El estudio descriptivo correlacional se realizó con 41 niños y sus madres, aplicándose cuestionarios sobre funcionamiento familiar, prácticas de crianza y desarrollo infantil. Los resultados señalaron la existencia de un funcionamiento familiar caracterizado por una cohesión amalgamada y una adaptabilidad caótica, una disciplina complaciente, falta de control y de límites claros en la díada madre-hijo. Se trataba de familias monoparentales, donde la temprana edad de concepción, el madresolterismo y el apoyo de la familia extensa eran constantes. Las edades evolutivas registradas indicaron un desarrollo inferior a la edad cronológica, en la mayor parte de los casos; sin embargo, éstas tendieron a ser superiores al compararlas con la edades reales de los infantes. No se encontró una correlación estadísticamente significativa entre la edad de desarrollo y los diferentes factores del funcionamiento familiar para algunos de los rangos de edad considerados; sin embargo, no se lo descartó por completo, especialmente en lo referente al optimismo familiar

  7. Everyday Life with ALS: A Practical Guide

    Science.gov (United States)

    ... the wheelchair plus its user, and more. Van shoppers can buy from a mobility dealer or directly ... Life with ALS: A Practical Guide 65 Connect Online with the ALS Community! MDA’s free online community — ...

  8. Formaline of alternatieven als ontsmettingsmiddel voor broedeieren

    NARCIS (Netherlands)

    Meijerhof, R.; Dijk, D.

    1997-01-01

    Formaline wordt algemeen gezien als een goed middel om broedeieren te ontsmetten. Toch geeft ontsmetting met middelen als ozon en waterstofperoxyde vaak een iets beter broedresultaat. Een eventuele verklaring hiervoor is momenteel nog niet te geven.

  9. Cenomanian-Turonian biostratigraphy of the Jardas Al Abid area, Al Jabal Al Akhdar, northeast Libya

    Science.gov (United States)

    El Qot, Gamal M.; Abdulsamad, Esam O.

    2016-09-01

    The Upper Cenomanian-Turonian succession exposed at Jardas al'Abid area consists mainly of carbonates with siliciclastic intercalations. This succession is subdivided lithostratigraphically into: Qasr al'Abid (Late Cenomanian) and Al Baniyah (Late Cenomanian-Coniacian) formations. This sequence is relatively rich in macrofossil assemblages especially bivalves, gastropods, and echinoids with rare ammonites. Based on the first occurrence (FO) and last occurrence (LO) of some index species of these macrofossil groups, an integrated biostratigraphic framework has been constructed. The studied Cenomanian-Turonian sequence is subdivided biostratigraphically into three ammonite biozones; Pseudaspidoceras pseudonodosoides Total Range Zone, Choffaticeras segne Total Range Zone, and Coilopoceras requienianum Total Range Zone. Based on the rest of macrofossil assemblages other than the ammonites, eight biozones were recognized; Mecaster batnensis Total Range Zone, Ceratostreon flabellatum-Neithea dutrugei Acme Zone, Costagyra olisiponensis Acme Zone, Pycnodonte (Phygraea) vesicularis vesiculosa Acme Zone, Mytiloides labiatus Total Range Zone = Mecaster turonensis Acme Zone, Rachiosoma rectilineatum-Curvostrea rouvillei-Tylostoma (T.) globosum Assemblage Zone, Radiolites sp.-Apricardia? matheroni Total Range Zone, and Nerinea requieniana Total Range Zone. Most of the proposed biozones are recorded for the first time from Libya. The integration among these biozones as well as local and inter-regional correlation of the biozones have been discussed. The stage boundaries of the studied stratigraphic intervals are discussed, where the Cenomanian/Turonian boundary is delineated at the last occurrence (LO) of Pseudaspidoceras pseudonodosoides (Choffat), while the Turonian/Coniacian boundary is delineated arbitrary being agree with the LO of the Turonian fauna.

  10. Grainreifnementlimit of commercialpureAl inoculatedbyAl-Ti-C(B)masteralloys

    Institute of Scientific and Technical Information of China (English)

    En-zhao Wang; Xiang-fa Liu

    2015-01-01

    The grain reifnement limits of commercial pure Al inoculated by Al-5Ti-1B, Al-5Ti-0.25C and Al-5Ti-0.3C-0.2B master al oys were studied, and the inlfuence of melting temperature on the grain reifning performance of these three master al oys was investigated using a high scope video microscope (HSVM), a ifeld-emission scanning electron microscope (FESEM), an electron probe micro-analyzer (EPMA) and X–ray diffraction (XRD) method. Results show that there is a grain reifnement limit of commercial pure Al reifned by these three master al oys; with the same addition level of 1.5% under the present experimental conditions, the grain reifnement limits (smal est average grain size) of commercial pure Al reifned by Al-5Ti-1B, Al-5Ti-0.25C and Al-5Ti-0.3C-0.2B master al oys are 50 µm, 80 µm and 80 µm, respectively. In addition, with an increase in the melting temperature of the pure Al, the grain reifning performance of Al-5Ti-1B and Al-5Ti-0.25C master al oys decreases, but the grain reifning performance of Al-5Ti-0.3C-0.2B changes little.

  11. Framework Al zoning in zeolite ECR-1.

    Science.gov (United States)

    Shin, Jiho; Ahn, Nak Ho; Cho, Sung June; Ren, Limin; Xiao, Feng-Shou; Hong, Suk Bong

    2014-02-25

    Rietveld analyses of the synchrotron X-ray diffraction data for various cation forms of zeolite ECR-1 have demonstrated framework Al zoning, which parallels the alternation of Al-rich maz and Al-poor mor layers. This can be further supported by notable differences in the average bond valence of its 10 crystallographically distinct tetrahedral sites.

  12. Electroplating Zn-Al Alloy Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The method of controlling separating anode and separating power source was used to perform orthogonal optimization for the parameters in electroplating Zn-Al alloy.The electroplating Zn-Al alloy technology was decided, in which the content of Al is about 12%-15%.

  13. Transport Properties of the Tunnel Junctions Al1-xCox/{Al1-xCox-oxide}/Al

    Institute of Scientific and Technical Information of China (English)

    X.F.Han; J. Murai; H.Kubota; Y.Ando; Q.Y.Wang; N.Tezuka; T.Miyazaki

    2000-01-01

    The oxides of Al1-xCox (x=0,0.25,0.5,0.75, and 1.0) alloys were chosen as barrier materials in this work. The tunnel junction consists of the bottom electrode Al1-xCox and the top electrode Al with an insulating layer { Al1-xCox-oxide} which was formed by natural oxidation in a baking-box at 333K. The oxidation time for forming an Al1-xCox-oxide layer on the surface of the bottom Al1-xCox layers were optimized.The resistance of Al1-xCox/{ Al1-xCox-oxide}/Al tunnel junctions varied between 101 and 106 Ω measured at 1 my and 4.2 K. The effective barrier height and width of insulating layers Al1-xCox-oxide ( x=0.25, 0.5, and 0.75 )varied between 0.6 and 2.7 eV and between 1.3 and 2.1 nm. It is shown that the thin oxide layer of Al1-xCox alloys can be chosen as barrier materials.

  14. Oxidation protection of NiCoCrAlY coatings on γ-TiAl

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-min; GUO Ming-hu; KE Pei-ling; GONG Jun; SUN Chao; WEN Li-shi

    2005-01-01

    The effect of NiCoCrAlY overlay coatings on the oxidation resistance of γ-TiAl was studied at 900 ℃ in static air. To hinder the interdiffusion of the elements, the Al/Al2O3 layer was added between the coating and the alloy. The results show that the TiAl alloy exhibits poor oxidation resistance. NiCoCrAlY coating can not effectively protect the γ-TiAl substrate from high temperature oxidation because of the serious interdiffusion between the coating and the substrates. With Al/Al2O3 diffusion barrier, the NiCoCrAlY coating exhibits excellent oxidation protection on γ-TiAl alloy.

  15. Trato verbal paterno al adolescente

    Directory of Open Access Journals (Sweden)

    Rodríguez Juan Carlos

    1995-06-01

    Full Text Available

    En alguna ocasión se ha escuchado una palabra, que causa un sentimiento y a la vez un recuerdo, que lleva a evocar la adolescencia o la infancia, se recuerda quien la pronunciaba y en que ocasión la decía. Este es el poder que tiene una palabra y más aún si es dicha por el padre, puesto que este es la figura significativa que se lleva en la memoria. De aquí nace el interés de realizar un estudio, en donde se describe y analice la percepción y el sentimiento del adolescente, quien en esta etapa es vulnerable al cambio, ya que está buscando su propia identidad; que con el trato verbal paterno la encontrara sin ninguna dificultad o por el contrario nunca la encontrará.

     

  16. Entscheidung als Häresie

    Directory of Open Access Journals (Sweden)

    Jaanus Sooväli

    2014-06-01

    Full Text Available Man könnte sagen, dass Aristoteles so etwas wie eine traditionelle und dominierende Auffassung der Entscheidung in der westlichen Philosophie gründet. Das Ziel dieses Aufsatzes ist es, diese Auffassung von Aristoteles zu entwerfen, einige ihrer wichtigsten Probleme anzusprechen, und sie damit zu kontrastieren, was ich Jacques Derridas häretische „Konzeptualisierung“ der Entscheidung nennen würde. Es wird gezeigt, dass diese häretische Thematisierung von Derrida nicht nur und einfach mit dem traditionellen aristotelischen Begriff bricht, sondern vielmehr auch zu Recht einige seiner wichtigsten Züge auf solcher Weise schärft, dass von diesem radikalisierten Standpunkt die Behandlung von Aristoteles als die Annullierung der Entscheidung zum Vorschein kommt. Es wird zudem impliziert, wie Derridas häretische Auffassung die Erneuerung der Ethik und Politik mit sich bringt.

  17. Instandhaltungsmanagement als Gestaltungsfeld Ganzheitlicher Produktionssysteme

    Science.gov (United States)

    Dombrowski, Uwe; Schulze, Sven; Otano, Isabel Crespo

    Sich kontinuierlich verändernde Rahmenbedingungen, wie beispielsweise eine steigende Variantenvielfalt, verkürzte Produktlebenszyklen sowie Kundenforderungen nach höherer Qualität, kürzeren Lieferzeiten und geringeren Kosten, fordern von produzierenden Unternehmen eine stetige Anpassung der Prozesse, der Organisation und der Strukturen. Seit den 90er Jahren versuchen immer mehr deutsche Unternehmen diesen veränderten Anforderungen mit der Einführung eines Ganzheitlichen Produktionssystems (GPS) zu begegnen. Ganzheitliche Produktionssysteme sind dabei in ihren Grundlagen an das Toyota Produktionssystem angelehnt, vereinigen aber auch weitere Methoden zu einem unternehmensspezifischen Regelwerk. Im Rahmen des langfristigen Trends zu unternehmensindividuellen Produktionssystemen wird sowohl in der Industrie als auch in der Forschung intensiv über das Toyota Produktionssystem, Lean Production, Lean Management und Ganzheitliche Produktionssysteme diskutiert, werden Konzepte zu Implementierung und Betrieb erstellt und die Wirtschaftlichkeit untersucht.

  18. Description of hypoeutectic Al-Si-Cu alloys based on their known chemical compositions

    Directory of Open Access Journals (Sweden)

    Djurdjevic, M. B.

    2013-10-01

    interés durante las últimas décadas, y la cantidad de programas de simulación existentes en el mercado es un buen indicador del interés de la industria en este campo. La mayoría de los datos empleados en estos programas se basan en los diagramas de fase binarios, ternarios o incluso superiores. Desafortunadamente, excepto para los diagramas binarios, el ajuste de los datos no es lo suficiente bueno. Teniendo en cuenta que la mayoría de los sistemas binarios del aluminio están bien definidos se ha intentado convertir los sistemas multi-componentes en un pseudo binario sistema Al-Xi (en este caso el diagrama de fase Al-Si es el elegido como sistema de referencia. El nuevo algoritmo del Silicio Equivalente (SiEQ expresa la cantidad de los elementos de la aleación que son mayoritarios y minoritarios, a través de una cantidad “equivalente” de silicio. Este sistema puede emplearse para calcular varias características termo-físicas y de solidificación de sistemas multicomponentes, como las aleaciones de aluminio. Esto permite al modelo tener la capacidad de realizar predicciones de las características de la solidificación de las piezas fundidas, donde las velocidades de enfriamiento son bajas y las características del proceso de solidificación son bien conocidas, para evitar posibles problemas en la fundición. Este trabajo demuestra cómo el algoritmo del SiEQ puede ser empleado para el cálculo de las características de las temperaturas de solidificación de las aleaciones multi-componentes Al-Si, así como sus calores latentes y el factor de restricción del crecimiento del grano. El análisis estadístico de los resultados obtenidos en un amplio rango de composiciones químicas de la aleación, muestra una muy buena correlación entre los datos experimentales y los cálculos realizados con el SiEQ. La misma aproximación matemática podría ser aplicada para otros sistemas metálicos como el hierro y el magnesio, empleando el carbono equivalente en el

  19. Friction Stir Welding of Al 5052 with Al 6061 Alloys

    Directory of Open Access Journals (Sweden)

    N. T. Kumbhar

    2012-01-01

    Full Text Available Friction stir welding (FSW, a solid-state joining technique, is being extensively used in similar as well as dissimilar joining of Al, Mg, Cu, Ti, and their alloys. In the present study, friction stir welding of two aluminium alloys—AA6061 and AA5052—was carried out at various combinations of tool rotation speeds and tool traverse speeds. The transverse cross-section of the weld was used for optical as well as electron microscopy observations. The microstructural studies were used to get an indication of the extent of material mixing both at the macro- and microscales. It was observed that, at the interface region, both materials exhibited similar texture despite the nonrigorous mixing of the materials in the nugget. The extent of interdiffusion of alloying elements at the interface was studied using electron probe microanalysis. The tensile testing evaluation of these specimens showed good mechanical properties. The interdiffusion of alloying elements and development of similar orientations in the nugget could have contributed to the better tensile properties of the friction-stir-welded AA5052-AA6061 specimens.

  20. Al-Fe-Si、Al-Mn-Si与Al-Fe-Mn-Si体系热力学描述的更新%Update of Al-Fe-Si, Al-Mn-Si and Al-Fe-Mn-Si thermodynamic descriptions

    Institute of Scientific and Technical Information of China (English)

    陈海林; 陈清; 杜勇; Johan BRATBERG; Anders ENGSTR(O)M

    2014-01-01

    采用Calphad方法对Al-Fe-Mn-Si四元系及其子体系进行热力学评估.首先,通过考虑文献中最新的实验研究结果以及对部分三元化合物应用新的热力学模型,修正Al-Fe-Si三系的热力学描述,显著地改善了整个成分范围内、尤其是富Al角的液相面投影图.随后,对三元化合物α-AlMnSi和β-AlMnSi采用新的模型,精修Al-Mn-Si体系富Al角的热力学描述.然后,通过模拟α-AlMnSi相在Al-Fe-Mn-Si体系中的固溶度,优化Al-Fe-Mn-Si四元系富Al角的热力学描述.在优化时,对α-AlMnSi作特殊考虑并加入限制条件,以确保其不会在Al-Fe-Si三元系中变得稳定.最后,将所获得的热力学描述加入TCAL数据库,通过一系列的相平衡计算与凝固模拟、以及与商业铝合金的实验数据的比较,对所获得的热力学描述进行全面的验证.更新后的TCAL数据库能够可靠地预测Al-Fe-Si基与Al-Fe-Mn-Si基合金中的相形成.

  1. Preparation and Characterization of Highly Flexible Al2O3/Al/Al2O3 Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Zhijiang Wang

    2015-01-01

    Full Text Available The natural brittleness of oxide ceramics heavily inhibits their more extensive applications. In present research, a highly flexible Al2O3/Al/Al2O3 hybrid composite was fabricated by employing plasma electrolysis oxidation to in situ grow alumina layers on Al foil, in which an outside layer of nanostructured polycrystalline oxide ceramic was composed of nanosized grains with the size of around 17 nm. Due to shear band formation, nanosized circle bubbles prolonging the crack path, grain rotation, and deformation, the fabricated Al2O3/Al/Al2O3 hybrid composite contains no observable cracks even after being bent on a cylindrical bar with a curvature of 1.5 mm. The composite exhibits alumina stiffness at the elastic stage and aluminum ductility during plastic deformation, which provides high flexibility with the well-integrated properties of the components. In a synergistic interaction, the alumina on the outside exhibited a strain of 0.33% at room temperature, which was higher than optimum value of 0.25% presented by reported most flexible oxide ceramics. With the unique characteristics and properties, the Al2O3/Al/Al2O3 composite demonstrates a great potential for various engineering applications.

  2. Cryptanalysis of Lin et al.'s Efficient Block-Cipher-Based Hash Function

    NARCIS (Netherlands)

    Liu, Bozhong; Gong, Zheng; Chen, Xiaohong; Qiu, Weidong; Zheng, Dong

    2010-01-01

    Hash functions are widely used in authentication. In this paper, the security of Lin et al.'s efficient block-cipher-based hash function is reviewed. By using Joux's multicollisions and Kelsey et al.'s expandable message techniques, we find the scheme is vulnerable to collision, preimage and second

  3. Magnetism of Al-substituted magnetite reduced from Al-hematite

    Science.gov (United States)

    Jiang, Zhaoxia; Liu, Qingsong; Zhao, Xiang; Roberts, Andrew P.; Heslop, David; Barrón, Vidal; Torrent, José

    2016-06-01

    Aluminum-substituted magnetite (Al-magnetite) reduced from Al-substituted hematite or goethite (Al-hematite or Al-goethite) is an environmentally important constituent of magnetically enhanced soils. In order to characterize the magnetic properties of Al-magnetite, two series of Al-magnetite samples were synthesized through reduction of Al-hematite by a mixed gas (80% CO2 and 20% CO) at 395°C for 72 h in a quartz tube furnace. Al-magnetite samples inherited the morphology of their parent Al-hematite samples, but only those transformed from Al-hematite synthesized at low temperature possessed surficial micropores, which originated from the release of structural water during heating. Surface micropores could thus serve as a practical fingerprint of fire or other high-temperature mineralogical alteration processes in natural environments, e.g., shear friction in seismic zones. In addition, Al substitution greatly affects the magnetic properties of Al-magnetite. For example, coercivity (Bc) increases with increasing Al content and then decreases slightly, while the saturation magnetization (Ms), Curie temperature (Tc), and Verwey transition temperature (Tv) all decrease with increasing Al content due to crystal defect formation and dilution of magnetic ions caused by Al incorporation. Moreover, different trends in the correlation between Tc and Bc can be used to discriminate titanomagnetite from Al-magnetite, which is likely to be important in environmental and paleomagnetic studies, particularly in soil.

  4. MARTENSITIC TRANSFORMATION AND THERMAL STABILITY IN Cu-Al-Co AND Cu-Al-Zr ALLOYS

    Institute of Scientific and Technical Information of China (English)

    Y. Q. Ma; C.B. Jiang; H.B. Xu

    2003-01-01

    Cu-Al-Co and Cu-Al-Zr alloys were explored with Co or Zr additions in Cu-Al alloys for high temperature shape memory alloys. Samples were quenched after homogenized at 850℃ for 48h. It was found that both Cu-Al-Co and Cu-Al-Zr show AlCu3 martensitic phase at room temperature and exhibit martensitic transformation temperatures higher than 200℃, showing the potentials for developing as high temperature shape memory alloys. Thermal cycles were performed by DSC instrument on both Cu-Al-Co and Cu-Al-Zr alloys. The results show that Cu-Al-Co loses its martensitic transformation after five thermal cycles, and Cu-Al-Zr exhibits no martensitic transformation in the second thermal cycle.

  5. Respuesta al Desgaste de un Material de Aluminio Reforzado con Circonia Response to wear of an Aluminum Material Reinforced with Zirconia

    Directory of Open Access Journals (Sweden)

    Rosalba Fuentes

    2006-01-01

    Full Text Available Se desarrolló un material compuesto aluminio-circonia por metalurgia de polvos. Los polvos de circonia fueron sintetizados por sol-gel, se mezclaron con polvo de aluminio, se compactaron y se sinterizaron. El tamaño del polvo de aluminio utilizado fue menor a 100 micras. La circonia tuvo como material precursor al n-propóxido de circonio. Se prepararon varias mezclas con ambos polvos, utilizando tres proporciones de circonia de 1%, 3% y 5% en peso. Se aplico una compactación de 58 KN y se sinterizó a 610°C. Posteriormente las piezas fueron sometidas a pruebas de desgaste con objeto de analizar su respuesta. El desgaste se realizó en una máquina de pin-en-disco, con velocidad de 320 rpm y presión de desgaste 9 KN por un período de dos horas. Las pruebas de desgaste muestran el comportamiento tribológico del material compuesto observándose un au>mento de resistencia al desgaste cuando el porcentaje en peso de circonia se incrementa.An aluminum-zirconia composite was developed using powder metallurgy. Zirconia powder was synthesized by a sol-gel method, mixed with aluminum powder, and was compacted and sinterized. The particle size of the aluminum powder utilized was less than 100 microns. The precursor material of zirconia was an n-propoxide of zirconium. Different proportions of zirconia were used in three mixtures at 1%, 3% and 5% by weight. The mixtures were compacted at 58KN and were sinterized at 610°C. Subsequently, the pieces were subjected to wear resistance tests to determine their resistance. The wear test was carried out in a pin-in-disk machine at a speed of 320 rpm and load of 9 KN for a period of two hours. The wear resistance tests showed the tribologic behavior of this composite showing an increase in wear resistance when the weight percentage of zirconia increases.

  6. STUDY ON THE THERMODYNAMICS OF CuO/Al IN SITU Al2O3 REINFORCED Al MATRIX COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Y.Ma; Y.Hao; S.Z.Kou; X.N.Lu

    2004-01-01

    Based on the experiment and the thermodynamics analysis for CuO/Al system, it is founded that the compounding reaction of CuO/Al under low temperature is available. The general equation of adiabatic temperature of the system is set up, and the influence of resultant concentration and temperature on adiabatic temperature is theoretically analyzed. The values of heat effect of CuO/Al system under different temperature are also caculated.

  7. Entrevista al narrador Tommaso Pincio

    Directory of Open Access Journals (Sweden)

    Franco Zangrilli

    2016-07-01

    Full Text Available El autor Tommaso Pincio, seudónimo di Marco Colapietro (Roma, 1963, es sin lugar a dudas uno de los narradores de mayor proyección en el panorama literario de los últimos tiempos. Iniciada su carrera en 1999 con M., ha publicado títulos como Lo spazio sfinito (2000 y Un amore dell'altro mondo (2002, en el que narra la vida de Kurt Cobain, líder del grupo Nirvana, a través de la visión de un amigo imaginario. A estas dos novelas siguieron La ragazza che non era lei (2005, Gli alieni (2006 o Cinacittà. Memorie del mio delitto efferato (2008, ambientada en una Roma colonizada por los chinos y abandonada por los mismos romanos a causa de problemas medioambientales. Títulos como L'hotel a zero stelle (2011, un ensayo autobiográfico en el que plantea diálogos ficticios con algunos de los grandes nombres de la literatura o la más reciente Panorama (2015, le han hecho valerse un hueco provilegiado entre los nuevos narradores surgidos en estas primeras décadas de siglo. Justamente la publicación de esta última novela, Panorama, ha servido de excusa al profesor Franco Zangrilli, gran conocedor de su obra, a plantearle algunas preguntas sobre temas clave de su producción.

  8. Al-Si/Al2O3 in situ composite prepared by displacement reaction of CuO/Al system

    Directory of Open Access Journals (Sweden)

    Zhang Jing

    2010-02-01

    Full Text Available Al2O3 particle-reinforced ZL109 composite was prepared by in situ reaction between CuO and Al. The microstructure was observed by means of OM, SEM and TEM. The Al2O3 particles in sub-micron sizes distribute uniformly in the matrix, and the Cu displaced from the in situ reaction forms net-like alloy phases with other alloy elements. The hardness and the tensile strength of the composites at room temperature have a slight increase as compared to that of the matrix. However, the tensile strength at 350 ℃ has reached 90.23 MPa, or 16.92 MPa higher than that of the matrix. The mechanism of the reaction in the CuO/Al system was studied by using of differential scanning calorimetry(DSC and thermodynamic calculation. The reaction between CuO and Al involves two steps. First, CuO reacts with Al to form Cu2O and Al2O3 at the melting temperature of the matrix alloy, and second, Cu2O reacts with Al to form Cu and Al2O3 at a higher temperature. At ZL109 casting temperature of 750–780 ℃, the second step can also take place because of the effect of exothermic reaction of the first step.

  9. Derecho civil : aproximaciones al derecho de personas

    OpenAIRE

    2005-01-01

    Las universidades de hoy, siguiendo las últimas tendencias de docencia universitaria que proponen minimizar la participación del profesor en la tarea del aprendizaje, han trasladado al estudiante al esfuerzo de apropiarse de la información necesaria para el conocimiento de las ciencias; Sin embargo, los libros y documentos que se entregan al estudiante para que se empape de los conceptos fundamentales siguen siendo textos fríos y desapacibles cuya utilidad estaba ligada a las explicaciones pr...

  10. Fabrication of AlN-TiC/Al composites by gas injection processing

    Institute of Scientific and Technical Information of China (English)

    YU Huashun; CHEN Hongmei; MA Rendian; MIN Guanghui

    2006-01-01

    The fabrication of AlN-TiC/Al composites by carbon-and nitrogen-containing gas injection into Al-Mg-Ti melts was studied. It was shown that AlN and TiC particles could be formed by the in situ reaction of mixture gas (N2+C2H2+NH3) with Al-Mg-Ti melts. The condition for the formation of AlN was that the treatment temperature must be higher than 1373 K, and the amounts of AlN and TiC increased with the increase of the treatment temperature and the gas injection time.It was considered that AlN was formed by the direct reaction of Al with nitrogen-containing gas at the interface of the gas bubble and the melt. However, the mechanism of TiC formation is a combination mechanism of solution-precipitation and solid-liquid reaction.

  11. Casting fabrication of in situ Al3Ti-Al composites and their wear behaviors

    Institute of Scientific and Technical Information of China (English)

    Chen Tijun; Li Jian; Hao Yuan

    2009-01-01

    The Al3li intermetallic reinforced pure Al, Al-13Si and Al-17Cu matrix composites were prepared by casting method. Their microstructures and dry sliding wear behaviors at room temperature and 100℃ were particularly investigated. The results indicated that the Al3Ti phases in these composites were all in flaky form. But the aspect ratio of the Al3Ti platelets decreased with the increase of Ti content in the pure AI, Al-Cu and Al-Si matrix composites, in order of effectiveness. The effect of Si on the Al3Ti morphology seemed to be greater than that of Cu. The distributions of the Al3Ti platelets were different in the different matrix composites, leading to different grain refining effects. Except for the sub-wear regime of adhesive wear, the plastic deformation induced wear was a dominant wear mechanism for all of the composites at room temperature and 100℃. Increasing the testing temperature, decreasing the Al3Ti content or the hardness of materials could enhance these two wear mechanisms, and thus increase the wear rate. The Al-Cu matrix composite had the best wear resistance, while the pure Al matrix composite showed the worst for the same Ti content. These differences or changes were attributed to the differences in materials' hardness or the strengthening effects of the Al3Ti platelets.

  12. First-principles study of the Al(001)-Al3Nb(001) interfacial properties

    Science.gov (United States)

    Ding, Yanhong; Xu, Rui

    2017-03-01

    The adhesion, interfacial energy and bonding on fcc-Al(001)/D022-Al3Nb(001) interface were investigated using density functional calculations. Considering different terminations of Al3Nb(001) (Al+Nb-terminated and Al-terminated) and stacking sites (top-, bridge- and center-sites), six Al(001)/Al3Nb(001) models were calculated. For the models with same stacking site, Al+Nb-terminated model has larger work of adhesion (Wad) than the Al-terminated one. For the models with same termination, the work of adhesion increases, and the interface energy decreases as the order of center-sited, bridge-sited and top-sited. Al+Nb-terminated-center-sited and Al-terminated-center-sited models are more stable among six models. The interfacial bonding was discussed with analysis of valence electron density distribution and partial density of states (PDOS). The bonding is mainly contributed from Al-Nb covalent bonds and Al-Al metallic interactions.

  13. Electrodeposition of Al from a 1-butylpyrrolidine-AlCl3 ionic liquid

    Directory of Open Access Journals (Sweden)

    Giridhar Pulletikurthi

    2015-12-01

    Full Text Available The addition of 1-butylpyrrolidine to AlCl3 results in the formation of an electrolyte that is suited to Al deposition. The feasibility of electrodepositing Al from the synthesized electrolyte was investigated. Several compositions of AlCl3 and 1-butylpyrrolidine were prepared for this purpose. These mixtures show a different phase behavior at various compositions of AlCl3 and 1-butylpyrrolidine. IR, Raman and NMR spectroscopy were employed to characterize the synthesized liquids. Among the prepared compositions, 1:1.2 mol ratio of 1-butylpyrrolidine:AlCl3 and the upper phase of 1:1.3 mol ratio of 1-butylpyrrolidine:AlCl3 were found to be suitable for Al electrodeposition at room temperature (RT. Uniform and thick (~µm thick layers of Al were obtained on copper at RT. Al deposition occured from the cationic species of AlCl3−xLy+ (where x≤2, y=1–2, and L=1-butylpyrrolidine in this electrolyte. This behavior is contrary to the well investigated classic AlCl3 based ionic liquids, where the deposition of Al occurs mainly from anionic Al2Cl7− ions.

  14. Groente- en fruitafvallen als veevoer : inventarisatie

    NARCIS (Netherlands)

    Vries, de A.

    1982-01-01

    Een onderzoek wat betreft hoeveelheden, bewaring, samenstelling, verteerbaarheid en eventueel aanwezige ongewenste stoffen van de bij- en afvalprodukten van groenten en fruit als veevoer voor herkauwers

  15. Effect of Excess Al in TiO2-Al Powder Mixture and Susceptor Material on Microwave Synthesis of TiAl/Al2O3 Composite

    Directory of Open Access Journals (Sweden)

    P. Radmehr

    2016-03-01

    Full Text Available In this research, TiAl/Al2O3 composite was synthesized from mechanically activated TiO2-Al powder mixtures using microwave heating.The initial powder mixtures were mechanically activated and pressed into cylindrical tablets and then heated in a microwave oven. The effect of different amounts of excess Al and microwave susceptor material (SiC or graphite on the ignition time and the resultant reaction products were evaluated. X-ray diffraction (XRD and scanning electron microscopy (SEM analysis were used for characterization of the synthesized samples. XRD patterns revealed that when there was no excess Al in the initial powder mixture, the main resulting intermetallic phase would be Ti3Al with negligible amounts of TiAl, while with 10 wt% excess Al, TiAl phase could be formed in the composite product.The results also showed that microwave synthesis took place faster and more reproducible when samples were packed in the graphite powder than when placed between two SiC blocks.

  16. Genetics of Familial and Sporadic ALS

    Science.gov (United States)

    2016-03-21

    Amyotrophic Lateral Sclerosis (ALS); Familial Amyotrophic Lateral Sclerosis; Amyotrophic Lateral Sclerosis With Frontotemporal Dementia; Lou Gehrig's Disease; Motor Neuron Disease; Primary Lateral Sclerosis

  17. Interfacial Phenomena in Al/Al, Al/Cu, and Cu/Cu Joints Soldered Using an Al-Zn Alloy with Ag or Cu Additions

    Science.gov (United States)

    Pstruś, Janusz; Gancarz, Tomasz

    2014-05-01

    The studies of soldered joints were carried out in systems: Al/solder/Al, Al/solder/Cu, Cu/solder/Cu, where the solder was (Al-Zn)EUT, (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Ag and (Al-Zn)EUT with 0.5, 1.0, and 1.5 at.% of Cu addition. Brazing was performed at 500 °C for 3 min. The EDS analysis indicated that the composition of the layers starting from the Cu pad was CuZn, Cu5Zn8, and CuZn4, respectively. Wetting tests were performed at 500 °C for 3, 8, 15, and 30 min, respectively. Thickness of the layers and their kinetics of growth were measured based on the SEM micrographs. The formation of interlayers was not observed from the side of Al pads. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed.

  18. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions.

    Science.gov (United States)

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-07-12

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

  19. Atomic structure and oxygen deficiency of the ultrathin aluminium oxide barrier in Al/AlOx/Al Josephson junctions

    Science.gov (United States)

    Zeng, Lunjie; Tran, Dung Trung; Tai, Cheuk-Wai; Svensson, Gunnar; Olsson, Eva

    2016-07-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits.

  20. Respuesta inmune adaptativa al rotavirus

    Directory of Open Access Journals (Sweden)

    Manuel A. Franco

    2004-03-01

    Full Text Available

    El rotavirus (RV es un importante patógeno humano y el estudio de la respuesta inmune específica de éste en humanos, es un buen modelo para caracterizar la respuesta inmune de la mucosa intestinal (1. Nuestros estudios han tenido como objetivo la caracterización fenotípica y funcional de las células T y B específicas de RV con énfasis importante en la expresión de marcadores de migración intestinal. Estas células son estudiadas en muestras de sangre periférica de niños y adultos recientemente infectados con RV. Los análisis se hicieron por citometría de flujo y ELISPOT. Estudio de células T: los adultos sanos presentan bajas frecuencias circulantes tanto de LT CD4+, como de LT CD8+ específicos de RV que secretan INF_ .

    Significativamente mayores porcentajes de éstas células se detectaron en adultos sintomáticos infectados por RV. Sin embargo, las frecuencias de LT específicos de RV en todos los grupos de estudio fueron muy bajas comparadas con las observadas para otros patógenos.

    Sorprendentemente, en niños sintomáticos infectados por RV se detectaron bajas frecuencias de LT CD8+ circulantes específicos de RV secretando INF-g y muy pocos o ningún LT CD4+ secretando INF-g o LT CD4+ y CD8+ al secretar IL-13 o IL4 (2,3. Esto sugiere que el RV es un inductor relativamente pobre de células T de memoria secretando estas citoquinas. Los LT circulantes CD4+ , INF-g.+ específicos de RV presentes en adultos

  1. Influence of AlN thickness on AlGaN epilayer grown by MOCVD

    Science.gov (United States)

    Jayasakthi, M.; Juillaguet, S.; Peyre, H.; Konczewicz, L.; Baskar, K.; Contreras, S.

    2016-10-01

    AlGaN/AlN layers were grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates. The AlN buffer thickness was varied from 400 nm to 800 nm. The AlGaN layer thickness was 1000 nm. The crystalline quality, thickness and composition of AlGaN were determined using high resolution X-ray diffraction (HRXRD). The threading dislocation density (TDD) was found to decrease with increase of AlN layer thickness. Reciprocal space mapping (RSM) was used to estimate the strain and relaxation between AlGaN and AlN. The optical properties of AlGaN layers were investigated by temperature dependent photoluminescence (PL). PL intensities of AlGaN layers increases with increasing the AlN thickness. The surface morphology of AlGaN was studied by atomic force microscopy (AFM). Root mean square (RMS) roughness values were found to be decreased while increase of AlN thickness.

  2. Kus on al-Zarqawi? / Aadu Hiietamm

    Index Scriptorium Estoniae

    Hiietamm, Aadu, 1954-

    2005-01-01

    Suurbritannia nädalalehe Sunday Times andmetel on Iraagi tagaotsituim mässaja, terrorivõrgustiku al Qaeda liitlane Abu-Musab al-Zarqawi pärast USA raketirünnakus haavatasaamist riigist põgenenud

  3. Al-Farabi dan Filsafat Kenabian

    Directory of Open Access Journals (Sweden)

    Qosim Nursheha Dzulhadi

    2014-03-01

    Full Text Available Artikel ini mengulas pemikiran al-Farabi tentang konsep kenabian dalam Islam. Masalah berawal dari adanya pemikiran yang menolak konsep kenabian pada umumnya dan kenabian Nabi Muhammad SAW khususnya. Sebagaimana yang dilontarkan oleh Muhammad Ahmad ibn al-Ruwandi. Ia mengatakan bahwa nabi sebenarnya tidak diperlukan manusia karena Tuhan telah mengaruniakan akal kepada manusia tanpa terkecuali. Dengan akal ini, manusia dapat mengetahui Tuhan beserta segala nikmat Nya dan dapat pula mengetahui perbuatan baik dan buruk, menerima suruhan dan larangan-Nya. Dengan demikian, nabi dengan segala fungsinya tidak diperlukan lagi. Bahkan, kitab suci pun tidak berguna untuk dibaca. Lebih berguna membaca buku filsafat Epicurus, Plato, Aristoteles, dan buku astronomi, logika, serta obat-obatan. Hal ini tentunya bertolak belakang dengan yang diajarkan dalam Islam. Beriman kepada nabi nabi merupakan hal inti dalam ajaran agama ini. Atas dasar itu al-Farabi bereaksi keras. Baginya, pandangan Ibn al-Ruwandi di atas tidak dapat dibenarkan, khususnya dari sisi akidah Islam. Sebagai al-Mu‘allim al-Tsani (Guru Kedua, karena prestasinya dalam menjelaskan dan mengulas-ulang filsafat Aristoteles, al-Farabi mengkritik secara sistematik pandangan menyimpang al-Ruwandi di atas.

  4. Diana Al-Hadid: Identity and Heritage

    Science.gov (United States)

    Jungerberg, Tom; Smith, Anna; Borsh, Colleen

    2012-01-01

    Diana Al-Hadid's sculptures reflect the many locations, cultures, histories, and mythologies that have shaped her as an artist. In large-scale works which have the appearance of architectural ruins, Al-Hadid employs imagery drawn from many diverse interests including science and technology, history, and literature. She also incorporates images and…

  5. The role of inclusions in ALS pathogenesis

    NARCIS (Netherlands)

    V. van Dis (Vera)

    2012-01-01

    textabstractAmyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that primarily afflicts motor neurons, leading to paralysis and death within 3 to 5 years after diagnosis. Genetic studies have uncovered multiple genetic defects causing familial forms of ALS and mutations oc

  6. Ceramic foams for Al-recycling

    Energy Technology Data Exchange (ETDEWEB)

    Luyten, J.; Vandermeulen, W.; Schutter, F. de [VITO, Materials Technology, Mol (Belgium); Simensen, C. [Sintef, Materials Technology, Blindern, Oslo (Norway); Ryckeboer, M. [Remi Claeys Aluminium, Lichtervelde (Belgium)

    2006-08-15

    The recycling of Al scrap requires an efficient purification step. In this investigation a filter technique is used to remove intermetallic compounds containing Fe, Mn and Si out of the molten Al. The paper describes the synthesis of the filters, the construction of the filter installation, and the results of the different filter tests. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  7. Konsepsi Ibnu Jarir Al-Tabari Tentang Al-Qur’an, Tafsir Dan Ta’wil

    Directory of Open Access Journals (Sweden)

    A.M Ismatulloh

    2012-12-01

    Full Text Available The objective of this research is to describe the concept of Ibnu Jarir al-Tabari about al-Qur’an, tafsir and ta’wil. Ibn Jarir al-Tabari is an outstanding expert in the classic Islamic tradition. His knowledge in hadits, fiqh, lughah, history, and tafseer is unquestionable. This study uses an analytical descriptive design. The findings show that: Firstly, in defining al-Qur’an, al-Tabari focused on the al-Qur’an as an Arabic language text, not in other language. Secondly, al-Qur’an is written in sab’ah ahruf. It means that there are 7 different kinds of language with the same meaning. Thirdly, al-Qur’an comes from seven heaven’s door. Fourthly, there is no different word between tafseer and ta’wil. They have same meaning. These concepts are different to other concepts proposed by other ulama.

  8. Kinetic Monte Carlo of transport processes in Al/AlOx/Au-layers: Impact of defects

    Directory of Open Access Journals (Sweden)

    Benedikt Weiler

    2016-09-01

    Full Text Available Ultrathin films of alumina were investigated by a compact kMC-model. Experimental jV-curves from Al/AlOx/Au-junctions with plasma- and thermal-grown AlOx were fitted by simulated ones. We found dominant defects at 2.3-2.5 eV below CBM for AlOx with an effective mass mox∗=0.35 m0 and a barrier EB,Al/AlOx≈2.8 eV in agreement with literature. The parameterization is extended to varying defect levels, defect densities, injection barriers, effective masses and the thickness of AlOx. Thus, dominant charge transport processes and implications on the relevance of defects are derived and AlOx parameters are specified which are detrimental for the operation of devices.

  9. Data supporting Al-Abed et al., Environ. Sci.: Nano, 2016,

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data files representing each of the Figures and Tables published in Al-Abed et al., Environ. Sci.: Nano, 2016, 3, 593. The data file names identify the Figure or...

  10. Effect of Al coating conditions on laser weldability of Al coated steel sheet

    Institute of Scientific and Technical Information of China (English)

    Jung-Han LEE; Jong-Do KIM; Jin-Seok OH; Seo-Jeong PARK

    2009-01-01

    Al coated steel sheets with excellent heat resistance, thermal reflection, and corrosion resistance are widely used in various applications. The laser weldability of the Al coated steel sheet for full penetration welding was reported. The phenomenon caused by intermixed aluminum and behavior of aluminum in the weld were investigated. Al coated steel sheets that have various thickness and coating mass were prepared for laser welding. The effects of parameters such as welding conditions and Al coating conditions were investigated. Al content mixed in the weld after laser welding was evaluated, and then a correlation between the mixed Al and mechanical properties was investigated. The results show that the Al-rich zones which have Fe-Al intermetallic compounds are found in the weld. The intermetallic compounds cause the decreased strength of the weld.

  11. Wallada Bint al Mustakfi entre dos culturas

    OpenAIRE

    shreen Mahmoud Al Refai

    2013-01-01

    La princesa cordobesa Wallada Bint al Mustakfi bil-lah, hija del califa al Mustakfi Muhammad Ibn Abdel Rahman Ibn Obaidil-lah Ibn Al Nasir lidin Al-lah era una poetisa estimable, a quien los grandes poetas no podían superar. Era una mujer única, guapa y decente. Mantenía una relación sentimental con el  poeta y visir Ibn Zaydún. Dicha pasión, narrada por los poemas escritos por ambos amantes, se terminó por la separación debida a los celos, también de ambos;  al poeta le gustó la voz de una e...

  12. Thermoluminescence properties of AlN ceramics

    DEFF Research Database (Denmark)

    Trinkler, L.; Christensen, P.; Agersnap Larsen, N.

    1998-01-01

    The paper describes thermoluminescence (TL) properties of AlN:Y2O3 ceramics irradiated with ionising radiation. A high TL sensitivity of AlN:Y2O3 ceramics to radiation encouraged a study of the AlN ceramics for application as a dosimetric material. The paper presents experimental data on: glow...... curve, emission spectrum, dose response, energy dependence, influence of heating rate and fading rate. The measured TL characteristics were compared with those of well-known, widely used TLDs, i.e. LiF:Mg,Ti, LiF:Mg,Cu,P and Al2O3:C. It is concluded that AlN:Y2O3 ceramics showing a radiation sensitivity...

  13. The neuropathology of FTD associated With ALS.

    Science.gov (United States)

    Mackenzie, Ian R A

    2007-01-01

    There is increasing recognition of a clinical overlap between frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Recent advances in our understanding of the neuropathologic, biochemical, and genetic basis of these conditions provides evidence for a common underlying pathogenesis. The neuropathology in most cases of FTD with ALS is a subtype of frontotemporal lobar degeneration, characterized by neuronal inclusions that are immunoreactive for ubiquitin but not tau (frontotemporal lobar degeneration with ubiquitinated inclusions). These cases show significant pathologic overlap with clinically pure FTD and those with classic ALS. Moreover, the ubiquitinated pathologic protein in all these conditions has recently been identified as TDP-43. A number of families have been reported with autosomal dominant FTD-ALS linked to chromosome 9p and these also have TDP-43-positive frontotemporal lobar degeneration with ubiquitinated inclusions pathology. Together, these findings suggest that FTD-ALS is part of a clinicopathologic spectrum of disease, now identified as TDP-43 proteinopathies.

  14. NiAl alloys for structural uses

    Science.gov (United States)

    Koss, D. A.

    1991-01-01

    Alloys based on the intermetallic compound NiAl are of technological interest as high temperature structural alloys. These alloys possess a relatively low density, high melting temperature, good thermal conductivity, and (usually) good oxidation resistance. However, NiAl and NiAl-base alloys suffer from poor fracture resistance at low temperatures as well as inadequate creep strength at elevated temperatures. This research program explored macroalloying additions to NiAl-base alloys in order to identify possible alloying and processing routes which promote both low temperature fracture toughness and high temperature strength. Initial results from the study examined the additions of Fe, Co, and Hf on the microstructure, deformation, and fracture resistance of NiAl-based alloys. Of significance were the observations that the presence of the gamma-prime phase, based on Ni3Al, could enhance the fracture resistance if the gamma-prime were present as a continuous grain boundary film or 'necklace'; and the Ni-35Al-20Fe alloy was ductile in ribbon form despite a microstructure consisting solely of the B2 beta phase based on NiAl. The ductility inherent in the Ni-35Al-20Fe alloy was explored further in subsequent studies. Those results confirm the presence of ductility in the Ni-35Al-20Fe alloy after rapid cooling from 750 - 1000 C. However exposure at 550 C caused embrittlement; this was associated with an age-hardening reaction caused by the formation of Fe-rich precipitates. In contrast, to the Ni-35Al-20Fe alloy, exploratory research indicated that compositions in the range of Ni-35Al-12Fe retain the ordered B2 structure of NiAl, are ductile, and do not age-harden or embrittle after thermal exposure. Thus, our recent efforts have focused on the behavior of the Ni-35Al-12Fe alloy. A second parallel effort initiated in this program was to use an alternate processing technique, mechanical alloying, to improve the properties of NiAl-alloys. Mechanical alloying in the

  15. Stabilization of itinerant (band) magnetism in FeAl by Ga substitution for Al

    Energy Technology Data Exchange (ETDEWEB)

    Papaconstantopoulos, D. A.; Mazin, I. I.; Hathaway, K. B.

    2001-06-01

    Band structure calculations of FeGa{sub 1{minus}x}Al{sub x} have been performed, to further investigate the stability of ferromagnetism in FeAl. The Stoner parameter increases by about 20% at the FeGa end. This is also confirmed by our spin-polarized calculations. We conclude that Ga substitution for Al is likely to stabilize the elusive (or illusive) ferromagnetic state in FeAl. {copyright} 2001 American Institute of Physics.

  16. XAFS Study of the Al K-Edge in NaAlH4

    NARCIS (Netherlands)

    Balde, C.P.; Mijovilovich, A.E.; Koningsberger, D.C.; van der Eerden, A.M.J.; Smith, A.D.; de Jong, K.P.; Bitter, J.H.

    2007-01-01

    Al K-edge (1561.1 eV) XANES and EXAFS spectra of unoxidized NaAlH4, a hydrogen storage material, have been recorded in He atmosphere in a special in situ low-energy cell. The XANES spectrum of NaAlH4 is reported and compared to that of oxidized NaAlH4, thus illustrating the power of XANES spectrosco

  17. Memes als moderne Bildungsmedien: Humor als Medium pädagogischer Interaktion zur Wissenskonstruktion im Physikunterricht

    OpenAIRE

    Prescher, Thomas; Thees, Michael

    2015-01-01

    Memes stellen ein modernes Bildmedium dar. Im Beitrag wird die Frage verfolgt, ob Memes mit ihrem inhärenten Humor innerhalb des Unterrichts auch als Bildungsmedium dienen und didaktisch genutzt werden können. Dazu wird Humor als generalisiertes Kommunikationsmedium pädagogischer Interaktion beschrieben, um Memes als moderne Bildmedien - in ihrer Wirkung als humorvolle Form der affektiven und kognitiven Inkongruenzstiftung - zur Entwicklung von Fachkonzepten im Physikunterricht fassen zu könn...

  18. Corrosion Studies of 2195 Al-Li Alloy and 2219 Al Alloy with Differing Surface Treatments

    Science.gov (United States)

    Danford, M. D.; Mendrek, M. J.

    1998-01-01

    Corrosion studies of 2195 Al-Li and 2219 Al alloys have been conducted using the scanning reference electrode technique (SRET) and the polarization resistance (PR) technique. The SRET was used to study corrosion mechanisms, while corrosion rate measurements were studied with the PR technique. Plates of Al203 blasted, soda blasted and conversion coated 2219 Al were coated with Deft primer and the corrosion rates studied with the EIS technique. Results from all of these studies are presented.

  19. High temperature creep behaviour of Al-rich Ti-Al alloys

    Science.gov (United States)

    Sturm, D.; Heilmaier, M.; Saage, H.; Aguilar, J.; Schmitz, G. J.; Drevermann, A.; Palm, M.; Stein, F.; Engberding, N.; Kelm, K.; Irsen, S.

    2010-07-01

    Compared to Ti-rich γ-TiAl-based alloys Al-rich Ti-Al alloys offer an additional reduction of in density and a better oxidation resistance which are both due to the increased Al content. Polycrystalline material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical, scanning and transmission electron microscopy and XRD analyses. The high temperature creep of two binary alloys, namely Al60Ti40 and Al62Ti38 was comparatively assessed with compression tests at constant true stress in a temperature range between 1173 and 1323 K in air. The alloys were tested in the cast condition (containing various amounts of the metastable phases Al5Ti3 and h-Al2Ti) and after annealing at 1223 K for 200 h which produced (thermodynamically stable) lamellar γ-TiAl + r-Al2Ti microstructures. In general, already the as-cast alloys exhibit a reasonable creep resistance at 1173 K. Compared with Al60Ti40, both, the as-cast and the annealed Al62Ti38 alloy exhibit better creep resistance up to 1323 K which can be rationalized by the reduced lamella spacing. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded apparent activation energies for creep of Q = 430 kJ/mol for the annealed Al60Ti40 alloy and of Q = 383 kJ/mol for the annealed Al62Ti38 material. The latter coincides well with that of Al diffusion in γ-TiAl, whereas the former can be rationalized by the instability of the microstructure containing metastable phases.

  20. Dakwah Kultural Bayt al-Qur’an al-Akbar Ukiran Kayu Khas Melayu Palembang

    Directory of Open Access Journals (Sweden)

    Reza Pahlevi

    2016-07-01

    Full Text Available Penelitian ini berusaha mengungkap berbagai fenomena yang menggambarkan serangkaian kegiatan dakwah kultural Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang. Sehingga dapat diperoleh sejumlah informasi mengenai berbagai upaya penerapan program yang dimaksud. Penelitian ini dapat disimpulkan, pertama kontribusi Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang terhadap perkembangan metode dakwah kultural adalah dakwah melalui seni. Kedua, Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang sebagai tempat Wisata Religi yang sangat signifikan.   This research tries to reveal the various phenomenon that describe a series of cultural propaganda activities Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang. In order to obtain some informations about the efforts of the implementation of the program in question. It can be concluded, the first contribution of Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang on the development of methods of cultural propaganda is propaganda through art. Second Bayt al-Qur’an al-Akbar Ukiran Khas Melayu Palembang as a very significant Religious Tourism.

  1. Japanese version of the ALS-FTD-Questionnaire (ALS-FTD-Q-J).

    Science.gov (United States)

    Watanabe, Yasuhiro; Beeldman, Emma; Raaphorst, Joost; Izumi, Yuishin; Yoshino, Hiide; Masuda, Michihito; Atsuta, Naoki; Ito, Satoru; Adachi, Tadashi; Adachi, Yoshiki; Yokota, Osamu; Oda, Masaya; Hanashima, Ritsuko; Ogino, Mieko; Ichikawa, Hiroo; Hasegawa, Kazuko; Kimura, Hideki; Shimizu, Toshio; Aiba, Ikuko; Yabe, Hayato; Kanba, Makoto; Kusumi, Kimiyoshi; Aoki, Tetsuya; Hiroe, Yu; Watanabe, Hirohisa; Nishiyama, Kazutoshi; Nomoto, Masahiro; Sobue, Gen; Nakashima, Kenji

    2016-08-15

    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common clinical, genetic and neuropathological features. Some ALS patients have behavioral/personality changes, which could result in significant obstacles in the care provided by family members and caregivers. An easy screening tool would contribute greatly to the evaluation of these symptoms. We translated the ALS-FTD-Questionnaire, developed in the Netherlands, into Japanese (ALS-FTD-Q-J) and examined the clinimetric properties (internal consistency, construct and clinical validity). Patients with ALS and/or behavioral variant FTD (bvFTD) were evaluated alongside healthy controls in this multicenter study. All ALS patients, regardless of bvFTD status, were further evaluated by the frontal behavioral inventory (FBI) and for frontal/executive function, cognition, anxiety/depression, and motor functions. Data from 146 subjects were analyzed: ALS (92), ALS-bvFTD (6), bvFTD (16), and healthy controls (32). The internal consistency of the ALS-FTD-Q-J was good (Cronbach α=0.92). The ALS-FTD-Q-J showed construct validity as it exhibited a high correlation with the FBI (r=0.79). However, correlations were moderate with anxiety/depression and low with cognitive scales, in contrast to the original report, i.e. a moderate correlation with cognition and a low correlation with anxiety/depression. The ALS-FTD-Q-J discriminated ALS patients from (ALS-)bvFTD patients and controls. Thus, the ALS-FTD-Q-J is useful for evaluating Japanese ALS/FTD patients.

  2. WAHDAT AL WUJUD DALAM PEMIKIRAN IBNU ARABI

    Directory of Open Access Journals (Sweden)

    Abd Halim Rofi'ie

    2013-09-01

    Full Text Available Ibnu Arabi, the Grand Master of Islam, is a great thinker whose controversial thought, wahdat al-wujud, has significantly influenced the mystiques of Islam. The meaning of wahdat al-wujud is basically two folds, i.e. that Being is the only One which exists and that the universe is merely a manifestation of the One. The One Being here refers to Allah SWT. The One covers up all the existing phenomena and functions as a resource which emanates the entire universe. In this context, He is referred to as al-Haqiqat al-Muhammadiyah. He might also be viewed as both the Universal Soul for His being the source of cosmos that governs the universe and the Universal Body for His reflecting any actions on every single micro existence that forms the universe. Furthermore, when His existence is deemed as a jauhar (jewel that face-up any occurrences, He is typically known as al-haba’. The concept of wahdat al-wujud can actually be simplified into the principle of laa maujuda illa wujud al-wahid (no existence except the Existing One, the Being. The One might reveal His own existence into different martabat or levels: Martabat Ahadiyah, Martabat Wahidiyah, and Martabat Tajalli Syuhudi. Those standing points trigger Ibnu Arabi to believe that any kinds of realities or existences are nothing but a true reflection of the One.

  3. Thermal diffusion in Ni/Al multilayer

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.; Bhattacharya, D.; Singh, S.; Basu, S. [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Gupta, M. [UGC-DAE-Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

    2013-02-05

    Two Ni/Al multilayers deposited by ion beam sputtering of nominal design [Ni(200A)/Al(100A)] Multiplication-Sign 5 and [Ni(50A)/Al(227A)] Multiplication-Sign 5 on Si substrates were annealed at 200 Degree-Sign C. As-deposited and annealed samples were characterized by x-ray diffraction (XRD) and x-ray reflectometry (XRR). The effort was to study the path of alloying in the above two multilayers of same elements but of opposite stoichiometric ratio. We find distinct differences in alloying of these samples.

  4. Juan Goytisolo en al aule de ELE

    OpenAIRE

    Zubia Fernandez, Daniel

    2004-01-01

    Al integrar en el aula de ELE artículos periodísticos sobre un determinado escritor como una práctica de expresión oral y escrita, se aproxima al alumno principiante de ELE al universo literario del autor escogido con el propósito de entrelazar la enseñanza de la lengua y la de la(s) literatura(s) en lengua española. Con este enfoque se estimula la capacidad lectora del alumno en la lengua meta ya que los textos periodísticos constituyen modelos ejemplares para este propósito d...

  5. Characterization of different-Al-content AlGaN/GaN heterostructures on sapphire

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Al x Ga 1-x N/GaN high-electron-mobility transistor (HEMT) structures with Al composition ranging from x = 0.13 to 0.36 are grown on sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The effects of Al content on crystal quality, surface morphology, optical and electrical characteristics of the AlGaN/GaN heterostructures have been analyzed. Although high Al-content (36%) heterostructure exhibits a distinguished photoluminescence peak related to recombination between the two-dimensional electron gas and photoexcited holes (2DEG-h), its crystal quality and rough surface morphology are poor. 2DEG mobility increases with the Al content up to 26% and then it apparently decreases for high Al-content (36%) AlGaN/GaN heterostructure. The increase of sheet carrier density with the increase of Al content has been observed. A high mobility at room temperature of 2105 cm 2 /V s with a sheet carrier density of n s = 1.10 × 10 13 cm -2 , for a 26% Al-content AlGaN/GaN heterostructure has been obtained, which is approaching state-of-the-art for HEMT grown on SiC. Sheet resistance as low as 274 Ω/□ has also been achieved.

  6. Tracing Al Shabaab’s Decision to Cooperate with Al Qaeda in Somalia (2008

    Directory of Open Access Journals (Sweden)

    Adlini Ilma Ghaisany Sjah

    2014-02-01

    Full Text Available 'Al Shabaab, a Somali insurgent with predominantly nationalistic causes (alongside transnational [global Jihad] and Islamic goals made the choice to fight on behalf of Al Qaeda in 2008. The decision to do so contrasted with Al Shabaab’s previous behaviour of actively denying cooperation and distancing itself from Al Qaeda. This study aims to uncover factors that contributed to Al Shabaab’s decision through the use of process-tracing. The results show that Al Shabaab’s declaration of cooperation with Al Qaeda in August 2008 was brought about by a series of events that traced back to four factors: public reactions to the implementation of a Salafi ideology, the shift to a radical leadership, Al Shabaab’s inability to maintain stability in areas under its control and its increasing attacks by Al Shabaab on the Somali public. Al Shabaab pursued cooperation with Al Qaeda after realizing that their nationalistic preference was no longer achievable in the near future.' ' '

  7. InAlN/AlN/GaN heterostructures for high electron mobility transistors

    Science.gov (United States)

    Usov, S. O.; Sakharov, A. V.; Tsatsulnikov, A. F.; Lundin, V. W.; Zavarin, E. E.; Nikolaev, A. E.; Yagovkina, M. A.; Zemlyakov, V. E.; Egorkin, V. I.; Ustinov, V. M.

    2016-08-01

    The results of development of InAlN/AlN/GaN heterostructures, grown on sapphire substrates by metal-organic chemical vapour deposition, and high electron mobility transistors (HEMTs) based on them are presented. The dependencies of the InAlN/AlN/GaN heterostructure properties on epitaxial growth conditions were investigated. The optimal indium content and InAlN barrier layer thicknesses of the heterostructures for HEMT s were determined. The possibility to improve the characteristics of HEMTs by in-situ passivation by Si3N4 thin protective layer deposited in the same epitaxial process was demonstrated. The InAlN/AlN/GaN heterostructure grown on sapphire substrate with diameter of 100 mm were obtained with sufficiently uniform distribution of sheet resistance. The HEMTs with saturation current of 1600 mA/mm and transconductance of 230 mS/mm are demonstrated.

  8. Preparation and Mechanical Properties of Al2O3/Al Laminated Ceramic Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    HUANG Kangming; LI Weixin; XIE Binhuan; RAO Pinggen; PENG Cheng; CHEN Dabo; WU Jianqing

    2011-01-01

    Three series of Al2O3/Al laminated ceramic matrix composites,named SPA,SPV and HP,were fabricated by different methods.SPA and SPV were prepared using Al2O3 slices and Al slurry via screen printing and subsequent heat treatment in air or vacuum.HP samples were made by hot pressing the layered stack of Al foils and Al2O3 slices.SEM and XRD were applied to analyze the microstructure and the interlayer crystal phase.The bending strength,fracture toughness and fracture work of the samples made by the three methods were measured and compared.The results show that the composites have much better toughness and higher fracture work than the Al2O3 slice.Among the samples made by the three methods,the samples made by hot pressing have the optimum mechanical performance.The displacement-load curves and fracture mechanism were analyzed.

  9. The Y-Ag-Al system

    Energy Technology Data Exchange (ETDEWEB)

    Gumenyuk, T.M.; Kuz' ma, Yu.B.; Stel' makhovych, B.M. [L' vov State Univ. (Ukraine). Dept. of Anal. Chem.

    2000-03-14

    The interaction between the components in the Y-Ag-Al system at 870 K has been studied using X-ray analysis. The phase diagram in the region up to 50 at.% of yttrium has been constructed. The limits of the solid solution regions of the binary compounds and the homogeneity ranges of the ternary ones have been determined. The crystal structures of the ternary aluminides Y{sub 3}Ag{sub 2}Al{sub 7} (Ca{sub 3}Cu{sub 2}Al--type structure, space group R anti 3m, a=0.55422(2), c=2.6259(1) nm) and YAg{sub 0.6}Al{sub 1.4} (KHg{sub 2}-type structure, space group Imma, a=0.45399(2), b=0.71551(3), c=0.78712(4) nm) have been studied for the first time. (orig.)

  10. Calcium platinum aluminium, CaPtAl

    Directory of Open Access Journals (Sweden)

    Charles Fon Abi

    2011-10-01

    Full Text Available A preliminary X-ray study of CaPtAl has been reported previously by Hulliger [J. Alloys Compd (1993, 196, 225–228] based on X-ray powder diffraction data without structure refinement. With the present single-crystal X-ray study, we confirm the assignment of the TiNiSi type for CaPtAl, in a fully ordered inverse structure. All three atoms of the asymmetric unit have .m. site symmetry. The structure features a ∞3[AlPt] open framework with a fourfold coordination of Pt by Al atoms and vice versa. The Ca atoms are located in the large channels of the structure.

  11. 78 FR 4967 - Alabama Disaster #AL-00046

    Science.gov (United States)

    2013-01-23

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Alabama Disaster AL-00046 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... adversely affected by the disaster: Primary Counties: Mobile; Pike. Contiguous Counties: Alabama:...

  12. Smoking Tied to Shorter Survival with ALS

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161094.html Smoking Tied to Shorter Survival With ALS Tobacco use ... 22, 2016 WEDNESDAY, Sept. 21, 2016 (HealthDay News) -- Smoking may speed progression of Lou Gehrig's disease and ...

  13. Thermal Conductivity of Al-Salt Composites

    Science.gov (United States)

    Li, Peng; Zhang, Mei; Wang, Lijun; Seetharaman, Seshadri

    2015-11-01

    With a view to examine the possibility of estimating the content of entrapped metallic aluminium in the salt cake from aluminium remelting, the thermal diffusivity of reference composites of KCl-NaCl-Al was measured as a function of aluminium metal content at room temperature. The thermal conductivity of the reference composites was found to increase with the metallic Al content. The lumped parameter model approach was carried out to discuss the influence of different geometry arrangements of each phase, viz. air, salts and metallic aluminium on the thermal conductivity. Application of the present results to industrial samples indicates that factors such as the interfacial condition of metallic Al particles have to be considered in order to estimate the amount of entrapped Al in the salt cake.

  14. Are RENiAl hydrides metallic?

    Energy Technology Data Exchange (ETDEWEB)

    Eichinger, Karl; Havela, Ladislav; Prokleska, Jan; Stelmakhovych, Olha; Danis, Stanislav [Faculty of Mathematics and Physics, Charles Univ., Prague (Czech Republic); Santava, Eva [Inst. of Physics ASCR, Prague (Czech Republic); Miliyanchuk, Khrystyna [Dept. of Inorganic Chemistry, Ivan Franko National Univ. of Lviv (Ukraine)

    2009-09-15

    Due to hydrogenation, the crystal structure of GdNiAl distorts from hexagonal to orthorhombic. The magnetic ordering temperature decreases dramatically and the magnetic entropy of this phase transition is in good agreement with theory. LuNiAl does not change its structure type, but it was found that the electronic contribution to specific heat decreases dramatically. None of the two phases loses its metallic character. (orig.)

  15. L’impegno al tempo della globalizzazione

    DEFF Research Database (Denmark)

    Cecchini, Leonardo

    al dibattito sui rapporti (di reciproca esclusione? complementarità?) tra postmoderno e impegno e sul carattere di quest’ultimo oggi (politico? sociale? etico? ecologico? altro?). Prendendo le mosse dalle discussioni suscitate dalla presa di posizione teorica dei Wu Ming, nel mio intervento vorrei...... Romanistica», 8/2011, pgg. 129-143. Wu Ming, New Italian Epic. Letteratura, sguardo oblique, ritorno al futuro, Torino, Einaudi, 2009....

  16. Del latín al rumano

    Directory of Open Access Journals (Sweden)

    Montes Giraldo José Joaquín

    2003-06-01

    Full Text Available

    Marius Sala, Del latín al rumano. Versión española de Valeria Neagu, París, Unión Latina - Bucarest, Univers enciclopedic, 2002. El texto se dirige al lector corriente, no especialista, y por eso el aparato técnico-bibliográfico no se presenta en el curso de la exposición.

  17. Hypermetabolism as a Risk Factor for ALS

    Science.gov (United States)

    2012-07-01

    hypermetabolism related to loss of TDP-43, an essential RNA binding protein implicated in ALS and Frontotemporal dementia ( FTD ), may contribute to disease...with Paget’s disease of bone and FTD (IBMPFD), it will also be interesting to test whether hypermetabolism may also be a risk factor in these...mouse strain confers leanness and protects from diet-induced obesity. Nat Genet 40(11):1354-1359, 2008. 3. Stone S, et al: TBC1D1 is a candidate

  18. Line shape diagnostics of Galactic 26Al

    CERN Document Server

    Kretschmer, K; Hartmann, D H

    2003-01-01

    The shape of the gamma-ray line from radioactive 26Al, at 1808.7 keV energy in the frame of the decaying isotope, is determined by its kinematics when it decays, typically 10^6 y after its ejection into the interstellar medium from its nucleosynthesis source. Three measurements of the line width exist: HEAO-C's 1982 value of (0+3) keV FWHM, the GRIS 1996 value of (5.4 +/- 1.3) keV FWHM, and the recent RHESSI value of (2.0 +/- 0.8) keV FWHM, suggesting either "cold", "hot", or "warm" 26Al in the ISM. We model the line width as expected from Galactic rotation, expanding supernova ejecta, and/or Wolf-Rayet winds, and predict a value below 1 keV (FWHM) with plausible assumptions about 26Al initial velocities and expansion history. Even though the recent RHESSI measurement reduces the need to explain a broad line corresponding to 540 km/s mean 26Al velocity through extreme assumptions about grain transport of 26Al or huge interstellar cavities, our results suggest that standard 26Al ejection models produce a line ...

  19. In Situ Fabrication of AlN Coating by Reactive Plasma Spraying of Al/AlN Powder

    Directory of Open Access Journals (Sweden)

    Mohammed Shahien

    2011-10-01

    Full Text Available Reactive plasma spraying is a promising technology for the in situ formation of aluminum nitride (AlN coatings. Recently, it became possible to fabricate cubic-AlN-(c-AlN based coatings through reactive plasma spraying of Al powder in an ambient atmosphere. However, it was difficult to fabricate a coating with high AlN content and suitable thickness due to the coalescence of the Al particles. In this study, the influence of using AlN additive (h-AlN to increase the AlN content of the coating and improve the reaction process was investigated. The simple mixing of Al and AlN powders was not suitable for fabricating AlN coatings through reactive plasma spraying. However, it was possible to prepare a homogenously mixed, agglomerated and dispersed Al/AlN mixture (which enabled in-flight interaction between the powder and the surrounding plasma by wet-mixing in a planetary mill. Increasing the AlN content in the mixture prevented coalescence and increased the nitride content gradually. Using 30 to 40 wt% AlN was sufficient to fabricate a thick (more than 200 µm AlN coating with high hardness (approximately 1000 Hv. The AlN additive prevented the coalescence of Al metal and enhanced post-deposition nitriding through N2 plasma irradiation by allowing the nitriding species in the plasma to impinge on a larger Al surface area. Using AlN as a feedstock additive was found to be a suitable method for fabricating AlN coatings by reactive plasma spraying. Moreover, the fabricated coatings consist of hexagonal (h-AlN, c-AlN (rock-salt and zinc-blend phases and certain oxides: aluminum oxynitride (Al5O6N, cubic sphalerite Al23O27N5 (ALON and Al2O3. The zinc-blend c-AlN and ALON phases were attributed to the transformation of the h-AlN feedstock during the reactive plasma spraying. Thus, the zinc-blend c-Al

  20. Corrosion behavior of solid solution (Ti,Al)N as a function of Al concentration

    Energy Technology Data Exchange (ETDEWEB)

    Larijani, M.M.; Seyedi, H. [Nuclear Science and Technology Research Institute, P. O. Box 31485-498, Karaj (Iran, Islamic Republic of); Manouchehrian, M. [Department of Physics, Science Faculty, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Yari, M. [Engineering Department Materials, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2012-08-15

    In this work, a series of (Ti, Al) N coatings with different Al contents were deposited on 304 stainless steel substrates by Hollow Cathode Discharge (HCD) method. The coatings were grown on 304 stainless steel substrates at 400 C. The coatings were characterized using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), atomic force microscopy (AFM), and microhardness test. The XRD confirmed the transition from TiN phase to (Ti, Al) N phase and then to AlN phase with increasing Al concentration in the solid solution. It was found that with increasing Al concentration the hardness of the coatings initially increased up to a maximum value of about 30 GPa at around 32 at.% of Al and then the coating hardness decreased rapidly with further increase of Al content (Al > 32 at.%). The potentiodynamic polarization analysis was carried out in 3.5 wt.% NaCl solutions to study the corrosion resistance of the coatings. From the corrosion test it can be inferred that the amount of Al atoms in the coatings plays an important role for reducing the corrosion. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Thermodynamics and surface properties of liquid Al-Ga and Al-Ge alloys

    Energy Technology Data Exchange (ETDEWEB)

    Anusionwu, B.C. [Abdus Salam Int. Centre for Theoretical Physics, Trieste (Italy); Federal University of Technology, Department of Physics, Owerri (Nigeria); Adebayo, G.A. [Abdus Salam Int. Centre for Theoretical Physics, Trieste (Italy); University of Agriculture, Department of Physics, Abeokuta (Nigeria); Madu, C.A. [Federal University of Technology, Department of Physics, Owerri (Nigeria)

    2009-11-15

    The surface properties of Al-Ga and Al-Ge liquid alloys have been theoretically investigated at a temperature of 1100 K and 1220 K respectively. For the Al-Ga system, the quasi chemical model for regular alloy and a model for phase segregating alloy systems were applied, while for the Al-Ge system the quasi chemical model for regular and compound forming binary alloys were applied. In the case of Al-Ga, the models for the regular alloys and that for the phase segregating alloys produced the same value of order energy and same values of thermodynamic and surface properties, while for the Al-Ge system, the model for the regular alloy reproduced better the thermodynamic properties of the alloy. The model for the compound forming systems showed a qualitative trend with the measured values of the thermodynamic properties of the Al-Ge alloy and suggests the presence of a weak complex of the form Al{sub 2}Ge{sub 3}. The surface concentrations for the alloys show that Ga manifests some level of surface segregation in Al-Ga liquid alloy while the surface concentration of Ge in Al-Ge liquid alloy showed a near Roultian behavior below 0.8 atomic fraction of Ge. (orig.)

  2. Thermodynamics and surface properties of liquid Al-Ga and Al-Ge alloys

    Science.gov (United States)

    Anusionwu, B. C.; Adebayo, G. A.; Madu, C. A.

    2009-11-01

    The surface properties of Al-Ga and Al-Ge liquid alloys have been theoretically investigated at a temperature of 1100 K and 1220 K respectively. For the Al-Ga system, the quasi chemical model for regular alloy and a model for phase segregating alloy systems were applied, while for the Al-Ge system the quasi chemical model for regular and compound forming binary alloys were applied. In the case of Al-Ga, the models for the regular alloys and that for the phase segregating alloys produced the same value of order energy and same values of thermodynamic and surface properties, while for the Al-Ge system, the model for the regular alloy reproduced better the thermodynamic properties of the alloy. The model for the compound forming systems showed a qualitative trend with the measured values of the thermodynamic properties of the Al-Ge alloy and suggests the presence of a weak complex of the form Al2Ge3. The surface concentrations for the alloys show that Ga manifests some level of surface segregation in Al-Ga liquid alloy while the surface concentration of Ge in Al-Ge liquid alloy showed a near Roultian behavior below 0.8 atomic fraction of Ge.

  3. Heterogeneous nucleation of solid Al from the melt by Al 3 Ti : Molecular dynamics simulations

    KAUST Repository

    Wang, Junsheng

    2010-10-27

    It has been known experimentally for some time that Al3 Ti is a powerful nucleant for the solidification of aluminum from the melt; however, a full microscopic understanding is still lacking. To develop this understanding, we have performed molecular dynamics simulations of the nucleation and early stages of growth using published embedded atom method potentials for Al-Ti, but modified by us to stabilize the D 022 structure. We discover that Al3 Ti can indeed be very effective in promoting the growth of solid Al but the manner in which growth takes place depends sensitively on the surface on which the Al nucleates. In particular, complete growth of solid Al from the liquid on the (001) and (110) surfaces of Al3 Ti occurs at a lower temperature than on the (112) surface. This anisotropy agrees with observations in previous experiments. We explain this observation in terms of interfacial energies. On the preferential (111) surface of Al the solid-liquid interfacial energy is highest while the solid-vacuum energy is lowest. Our simulations also show that the extent of ordering taking place in liquid Al close to the Al 3 Ti substrate above the melting point correlates well with the effectiveness of the substrate as a nucleant below the melting temperature: this could provide a computationally efficient scheme to identify good nucleants. © 2010 The American Physical Society.

  4. Avance al estudio radiológico del armamento de la necrópolis ibérica del Cabecico del Tesoro (Verdolay, Murcia. I. - Las Falcatas

    Directory of Open Access Journals (Sweden)

    García Cano, José Miguel

    2006-12-01

    Full Text Available

    We present a new study of the falcata swords decorated with silver inlay from the Iberian Iron Age cemetery at Cabecico del Tesoro (Murcia. Already known pieces are re-studied, while we also present new examples of previously unknown decorations, hidden under the corrosion layers but visible under radiographic examination.



    Se presenta un nuevo estudio de las falcatas decoradas con damasquinados en plata de la necrópolis ibérica del Cabecico del Tesoro (Murcia, Se reestudian piezas conocidas y se presentan nuevos casos de decoraciones previamente ocultas bajo la corrosión pero visibles en un examen radiológico efectuado sobre las piezas.

  5. Al4C3 Hydration Thermochemical Analysis for Burned Carbon-containing Refractories with Al

    Institute of Scientific and Technical Information of China (English)

    YANG Ding'ao; YU Zhiming; FAN Liuwu

    2003-01-01

    In this paper, X-ray diffractogram analysis and SEM observation of Al4 C3 formed at high temperature from carbon-containing refractories with Al have been carried out.Aluminum added to carbon-containing refractories reacts with C(s)to form Al4 C3(s) gradually during heating from 600 ℃ to 1200℃.It is considered that the interlocked structure of Al4 C3 plate crystals promotes the outstanding increase of hot modulus of rupture of carbon-containing refractories with Al. The HMOR of carbon-containing refractories added with Al additive from 0 to 5wt% increases by 2.8 times being from 6.5MPa to 18.2MPa.After a thermochemical calculation for hydration reaction processes of Al4 C3 and H2O(g), the equilibrium partial pressure chart of H2O(g)in H2O-Al4C3-Al(OH)3 system vs various temperatures has been attained . The H2O (g) partial pressure in the air needed for the Al4 C3 hydration reaction is no more than 10~18 atm at the temperature below 120℃.It is considered that the burned carbon-containing refractories with Al is extremely easy to hydrate and the cracking of burned carbon-containing refractories is generated because that the hydration expansion is 2.11 times during transforming from Al4 C3 to Al(OH)3.The fundamental measure against hydration of the refractories is to insulate the refractories from H2O(g)by various means such as pitch impregnation or other sealing materials.

  6. Prinsip Pendidikan Karakter dalam Islam: Studi Komparasi Pemikiran Al-Ghazali dan Burhanuddin Al-Zarnuji

    Directory of Open Access Journals (Sweden)

    Agus Setiawan

    2014-06-01

    Full Text Available The impelemtantion of character education that is done by the Indonesian government recently has been provoked by al-Ghazali and Burhanuddin al-Zarnuji long ago. It was proven by some written thoughts of al-Ghazali and Burhanuddin al-Zarnuji. They were very famous scientists in their era and widely welknown as educational experts who produced some phenomenal thoughts many people use today. Al-Ghazali and Burhanuddin al-Zarnuji lived in the era of Bani Abbasiyah monarchy, but Both of them lived in different era. Al-Ghazali was born first, then Burhanuddin al-Zarnuji. They had different mazhab, al-Ghazali went to the traditional principle of mazhab Syafi’I and Burhanuddin al-Zarnuji went to the modern principle of mazhab Hanafi. The differences, of course, would create a different thought. Still, they might have a similar principle of Islamic character education. The thoughts of character education of al-Ghazali have been poured in the “Ayyuha Walad” focusing to the students’ character building characterized by religiously obedient, skillfull of general and religious knowledge, socially helpful, affectionate, generous, good citizen, and coloring the society. Some applicable thoughts of character education of Ayyuha al-Walad of al-Gazhali to the contemporary education are: the balance of the happiness purposes of the recent life and the life after death, qana’ah and tawakal, affectionate, caring other, patience, honesty, philanthrophy, social works, generousity, democratic, peace makers, and patriotic. Those characters are also directed in the islamic character education nowdays. So that, the thoughts of al-Ghazali positively and responsively are absorbed by the Indonesian government to build the national character widely implementing in the national curriculum based on the local wisdom and the Islamic values. In the end, the students are able to live happily based on the Islamic rules by implementing the good behavior. Similar to the al

  7. Microscopic Properties of Long-Period Ordering in Al-Rich TiAl Alloys

    Science.gov (United States)

    Hata, S.; Nakano, T.; Kuwano, N.; Itakura, M.; Matsumura, S.; Umakoshi, Y.

    2008-07-01

    The ordering mechanism of long-period superstructures (LPSs) in Al-rich TiAl alloys has been investigated by high-resolution transmission electron microscopy (HRTEM). The LPSs are classified in terms of arrangements of base clusters with different shapes and compositions formed in Ti-rich (002) layers of L10-TiAl matrix: square Ti4Al, fat rhombus Ti3Al, and lean rhombus Ti2Al type clusters. The HRTEM observations revealed that antiphase boundaries of long-range-ordered LPS domains and short-range-ordered microdomains are constructed by various space-filling arrangements of the base clusters. Such a microscopic property characterized by the base clusters and their arrangements is markedly analogous to that of the {left< {{text{1,1/2,0}}} rightrangle } * special-point ordering alloys such as Ni-Mo.

  8. Mechanochemical Synthesis and Rapid Consolidation of Nanocrystalline 3NiAl-Al2O3 Composites

    Directory of Open Access Journals (Sweden)

    In-Jin Shon

    2011-01-01

    Full Text Available Nanopowders of 3NiAl and Al2O3 were synthesized from 3NiO and 5Al powders by high-energy ball milling. Nanocrystalline Al2O3 reinforced composite was consolidated by high-frequency induction-heated sintering within 3 minutes from mechanochemically synthesized powders of Al2O3 and 3NiAl. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. The relative density of the composite was 97%. The average Vickers hardness and fracture toughness values obtained were 804 kg/mm2 and 7.5 MPa⋅m1/2, respectively.

  9. Effects of Al(III) and nano-Al13 species on malate dehydrogenase activity.

    Science.gov (United States)

    Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

    2011-01-01

    The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al(13) can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al(13) concentration increase. Our study also found that the effects of Al(III) and Al(13) on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

  10. Comparison of Al electromigration in conventional Al alloy and W-plug contacts to silicon

    Science.gov (United States)

    Oates, A. S.; Martin, E. P.; Alugbin, D.; Nkansah, F.

    1993-06-01

    We examine the impact of the presence of a W plug on electromigration-induced voiding of the Al alloy layer of contacts to silicon. By comparing conventional Al alloy and W-plug contacts we show that the presence of the plug does not significantly improve the intrinsic susceptibility of contacts to Al voiding despite the elimination of the Al step coverage problem. Both the conventional Al alloy and W-plug contacts degrade by drift of the Al layer with a velocity that is not influenced by the contact structure. The sheet resistance of the underlayer material of multilayer conductors plays an important role in influencing failure times since it determines the rate of resistance increase due to electromigration.

  11. Kinetic Monte Carlo of transport processes in Al/AlOx/Au-layers: Impact of defects

    Science.gov (United States)

    Weiler, Benedikt; Haeberle, Tobias; Gagliardi, Alessio; Lugli, Paolo

    2016-09-01

    Ultrathin films of alumina were investigated by a compact kMC-model. Experimental jV-curves from Al/AlOx/Au-junctions with plasma- and thermal-grown AlOx were fitted by simulated ones. We found dominant defects at 2.3-2.5 eV below CBM for AlOx with an effective mass mox ∗= 0.35 m0 and a barrier EB ,A l /A l O x≈2.8 eV in agreement with literature. The parameterization is extended to varying defect levels, defect densities, injection barriers, effective masses and the thickness of AlOx. Thus, dominant charge transport processes and implications on the relevance of defects are derived and AlOx parameters are specified which are detrimental for the operation of devices.

  12. Effects of Al(III and Nano-Al13 Species on Malate Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Rong Fu Chen

    2011-05-01

    Full Text Available The effects of different aluminum species on malate dehydrogenase (MDH activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT modified glass carbon electrode (GCE. The results showed that Al(III and Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III and Al13 concentration increase. Our study also found that the effects of Al(III and Al13 on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

  13. Superconductivity in Al/Al{sub 2}O{sub 3} interface

    Energy Technology Data Exchange (ETDEWEB)

    Palnichenko, A.V., E-mail: paln@issp.ac.ru; Vyaselev, O.M.; Mazilkin, A.A.; Khasanov, S.S.

    2016-06-15

    Highlights: • Al/Al{sub 2}O{sub 3} interface was formed by surface oxidation of Al foil. • Magnetic susceptibility and electrical resistance of the interface was studied. • Superconductivity at ∼ 65 K of the Al/Al{sub 2}O{sub 3} interface was observed. • The superconducting interface is instable under normal conditions. - Abstract: Metastable superconductivity at T{sub c} ≈ 65 K has been observed in Al foil subjected to special oxidation process, according to the ac magnetic susceptibility and electrical resistance measurements. Comparison of the ac susceptibility and the dc magnetization measurements infers that the superconductivity arises within the interfacial granular layer formed during the oxidation process between metallic aluminum and its oxide.

  14. Protective Al2O3 scale formation on NbAl3-base alloys

    Science.gov (United States)

    Doychak, J.; Hebsur, M. G.

    1991-01-01

    The oxidation of NbAl3 with additions of Cr and Y was studied to determine the mechanisms of the beneficial effects of these elements upon oxidation. Cr additions to the binary NbAl3 alloy of up to 6.8 at. percent reduced the scale growth rates and promoted alpha-Al2O3 formation over much longer times relative to binary NbAl3. A major effect of Cr is to form a layer of AlNbCr at the metal/scale interface, which is inherently more oxidation-resistant than the matrix alloy in the long term. Yttrium additions to a Cr-containing alloy improved the scale growth rate and adherence and changed the scale microstructure to mimic that of a typical protective Al2O3 scale.

  15. {sup 27}Al NMR studies of NpPd{sub 5}Al{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Chudo, H., E-mail: chudo.hiroyuki@jaea.go.j [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Sakai, H.; Tokunaga, Y.; Kambe, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Aoki, D.; Homma, Y.; Shiokawa, Y. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Y.; Ikeda, S.; Matsuda, T.D. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Onuki, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yasuoka, H. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

    2009-10-15

    We present {sup 27}Al NMR studies for a single crystal of the Np-based superconductor NpPd{sub 5}Al{sub 2}(T{sub c}=4.9K). We have observed a five-line {sup 27}Al NMR spectrum with a center line and four satellite lines separated by first-order nuclear quadrupole splittings. The Knight shift clearly drops below T{sub c}. The temperature dependence of the {sup 27}Al nuclear spin-lattice relaxation rate shows no coherence peak below T{sub c}, indicating that NpPd{sub 5}Al{sub 2} is an unconventional superconductor with an anisotropic gap. The analysis of the present NMR data provides evidence for strong-coupling d-wave superconductivity in NpPd{sub 5}Al{sub 2}.

  16. Preparation of TiAl3-Al composite coating by cold spraying

    Institute of Scientific and Technical Information of China (English)

    SHEN Li; KONG Ling-yan; XIONG Tian-ying; DU Hao; LI Tie-fan

    2009-01-01

    TiAl3-Al coating was deposited on orthorhombic Ti2AlNb alloy substrate by cold spraying with the mixture of pure Al and Ti as the feedstock powder at a fixed molar ratio of 3-1 when the spraying distance, gas temperature and gas pressure for the process were 10 mm, 250 ℃ and 1.8 MPa, respectively. The as-sprayed coating was then subjected to heat treatment at 630 ℃ in argon atmosphere for 5 h at a heating rate of 3 ℃/min and an argon gas flow rate of 40 mL/min. The obtained TiAl3-Al composite coating is about 212 μm with a density of 3.16 g/cm3 and a porosity of 14.69% in general. The microhardness and bonding strength for the composite coating are HV525 and 27.12 MPa.

  17. TEM characterization of oxidized AlGaAs/AlAs nonlinear optical waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Guillotel, E; Langlois, C; Ghiglieno, F; Leo, G; Ricolleau, C, E-mail: cyril.langlois@univ-paris-diderot.f [Laboratoire Materiaux et Phenomenes Quantiques, CNRS-UMR 7162 Universite Paris Diderot - Paris 7 Case courrier 7021, 75205 Paris Cedex 13 (France)

    2010-09-29

    The internal interfaces of multilayer Al{sub x}Ga{sub 1-x}As/AlAs nonlinear optical waveguides are investigated by high-angle annular-dark-field and energy-filtered scanning transmission electron microscopy, before and after partial wet oxidation of AlAs layers. Via a simple phenomenological model, the corresponding roughness parameters allow prediction of the scattering-induced waveguide optical losses, which are in reasonable agreement with the experimental value of 0.5 cm{sup -1}. We also find that Al{sub x}Ga{sub 1-x}As layers adjacent to oxidized AlAs tend to be oxidized through the interfaces, even for low Al fraction, with typical oxidation depths of 9 nm for x = 0.7 and 2 nm for x = 0.

  18. 60Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-Ping; LUO Yin-Hong; WANG Wei; ZHANG Ke-Ying; GUO Hong-Xia; GUO Xiao-Qiang; WANG Yuan-Ming

    2013-01-01

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established.The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically,and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out.The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated,and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

  19. Determination of Al Composition in Strained AlGaN Layers

    Institute of Scientific and Technical Information of China (English)

    ZHOU Sheng-Qiang; WU Ming-Fang; YAO Shu-De

    2005-01-01

    @@ Alx Ga1-x N/GaN heterostructures are grown on c-sapphire with the Al composition x from 0.2 to 0.4 and thicknesses from 20nm to 30nm. The lattice parameters a and c are determined from 2θ/ω scan. The AlGaN layers are found to be under tensile strain by using x-ray diffraction. Vegard's law induces a large deviation in Al composition determination by only considering the linear relationship between one lattice parameter (a or c) and Al composition. The accurate determination of Al composition is only possible with consideration of both the lattice parameters a and c, by assuming the tetragonal distortion in the AlGaN layer. Additionally, the results obtained from x-ray diffraction are verified by Rutherford backscattering.

  20. Cryptanalysis of Xinyu et al.'s NTRU-Lattice Based Key Exchange Protocol

    OpenAIRE

    Valluri, Maheswara Rao

    2016-01-01

    Xinyu et al. proposed a public key exchange protocol, which is based on the NTRU-lattice based cryptography. In this paper, we show how Xinyu et al.'s NTRU-KE: A lattice based key exchange protocol can be broken, under the assumption that a man-in-the middle attack is used for extracting private keys of users who participate in the key exchange protocol.

  1. Modified Mechanism of Eutectic Silicon in Al2O3/Al-Si Alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Al2O3/Al-Si alloy composite was manufactured by squeeze casting. The morphology of the eutectic silicon in the composite was observed by scanning electronic microscope (SEM), and the modified mechanism of eutectic silicon in the composite was approached. The alumina fiber in the composite can trigger twin during the growth of Al-Si eutectic and lead to the modification of eutectic silicon near the fiber.

  2. Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides

    Science.gov (United States)

    Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

    1998-01-01

    A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

  3. Another Security Improvement over the Lin et al.'s E-voting Scheme

    Science.gov (United States)

    Asaar, Maryam Rajabzadeh; Mohajeri, Javad; Salmasizadeh, Mahmoud

    In 2003, Lin et al. have proposed an electronic voting scheme which can be utilized in large-scale elections, and claimed it detects double voting. But in this paper, by presenting an attack, we show that voters can successfully vote more than once without being detected. Hence, we propose a new modified scheme based on the Lin et al.'s scheme with the same efficiency to solve this weakness and analyze its security.

  4. Compressive properties of a reaction milled NiAl-AlN composite

    OpenAIRE

    Whittenberger, J. Daniel; Arzt, Eduard; Luton, Michael J.

    1990-01-01

    Cryomilling (high intensity mechanical ball milling in a liquid nitrogen bath) of the B2 crystal structure nickel aluminide leads to a NiAl composite containing about 10 vol. % of AlN particles. This is the result of a reaction milling process, where nitrogen incorporated into the matrix during cryomilling reacts with Al during subsequent thermomechanical processing to form the composite. Compressive testing at 1300 K of such materials densified by 1505 K extrusion or isostatic pressing at 13...

  5. Generation and evolution of nanoscale AlP and Al{sub 13}Fe{sub 4} particles in Al-Fe-P system

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Huan; Gao, Tong; Zhu, Xiangzhen; Wu, Yuying; Qian, Zhao; Liu, Xiangfa, E-mail: xfliu@sdu.edu.cn

    2015-02-15

    Highlights: • Diffusion and gradual solid reactions between Al and Fe{sub x}P phases in Al-Fe-P alloy were investigated. • Nanoscale AlP clusters are in-situ generated and evolve during the whole process. • This novel Al-Fe-P alloy has an excellent low-temperature refining performance on hypereutectic Al-Si alloy. - Abstract: In this paper, the gradual solid reactions between Al and Fe{sub x}P phases in Al-Fe-P alloy were investigated. The results show that the whole reaction process undergoes four main stages: the diffusion of Al atom, the generation of (Al, Fe, P) intermediate compound, the precipitation of nano AlP and Al{sub 13}Fe{sub 4} clusters and their growth to submicron particles. The microstructure of Fe-P particles evolves from the “egg-type”, the “sponge-type” to the “sesame-cake” structure. AlP and Al{sub 13}Fe{sub 4} nano phases have in-situ generated and evolved during the whole process. The gradual reaction mechanism has been discussed. Furthermore, a novel Al-Fe-P alloy which contains (Al, Fe, P) intermediate compounds and nano AlP particles has been synthesized and its low-temperature refining performance on A390 alloy has also been investigated.

  6. Microstructure and thermal stability of mechanically alloyed Al3Ti/Al alloy

    Institute of Scientific and Technical Information of China (English)

    林建国; 魏浩岩; 黄正

    2001-01-01

    The microstructure stability of Al3Ti/Al alloy prepared by mechanical alloying (MA) was investigated in the simulating environment in which they may be used. The results show that the MA alloy possesses fine microstructure (the grain size is about 0.5  μm). After cycling loaded followed by heat exposure at 350  ℃ for 24  h, no microstructure coarsening of the alloy occurred, which means that the Al3Ti/Al alloy behaves good microstructure stability at high temperature. The compression yield strength of the alloy reaches up to 247  MPa at 350  ℃.

  7. Hydrolyzed Al(III) clusters: speciation stability of nano-Al13.

    Science.gov (United States)

    Wang, Dongsheng; Wang, Shuifeng; Huang, Chihpin; Chow, Christopher W K

    2011-01-01

    Pure nano-Al13 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR, photo correlation spectroscopy (PCS), and Ferron assay. Results showed that concentration and temperature exhibited different roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1-2 nm by PCS. Al13 solutions at high concentrations (0.5-2.11 mol/L) were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the 27Al-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations, Al13 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90 degrees C.

  8. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    Science.gov (United States)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  9. Hydrolyzed Al(Ⅲ) clusters: Speciation stability of nano-Al13

    Institute of Scientific and Technical Information of China (English)

    Dongsheng Wang; Shuifeng Wang; Chihpin Huang; Christopher W K. Chow

    2011-01-01

    Pure nano-Al13 and aggregates at various concentrations were prepared to examine the particle size effect of coagulation with inorganic polymer flocculant.The property and stability of various species formed were characterized using Infrared, 27Al-NMR,photo correlation spectroscopy (PCS), and Ferron assay.Results showed that concentration and temperature exhibited different roles on the stability of Al13.The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1-2 nm by PCS.Al13 solutions at high concentrations (0.5-2.11 mol/L) were observed to undergo further aggregation with aging.The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the 27Al-NMR spectrum, whereas a part of Al13 would still remain as Alb.At low concentrations,Al13 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90℃.

  10. CASTABILITY OF Al-Li-Mg AND Al-Li-Cu-Mg ALLOYS

    OpenAIRE

    1987-01-01

    The objective of the present work is to study the casting characteristics of various Al-Li alloys, which include fluidity and strengths of the alloys and their interaction with cast molds. Materials investigated are Al-Li-Mg and Al-Li-Cu-Mg alloys with Li content of 2.5 wt%. The results show that sand molds with resin binders are good for Al-Li casting. Ceramic coatings can further reduce the metal-mold interactions. However, the permeability is also reduced by coating. The fluidity of Li-bea...

  11. Growth of CdTe: Al films; Crecimiento de peliculas de CdTe: Al

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez A, M.; Zapata T, M. [CICATA-IPN, 89600 Altamira, Tamaulipas (Mexico); Melendez L, M. [CINVESTAV-IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico); Pena, J.L. [CINVESTAV-IPN, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico)

    2006-07-01

    CdTe: AI films were grown by the close space vapor transport technique combined with free evaporation (CSVT-FE). The Aluminum (Al) evaporation was made by two kinds of sources: one made of graphite and the other of tantalum. The films were deposited on glass substrates. The Al source temperature was varied maintaining the CdTe source temperature fixed as well as the substrate temperature. The films were characterized by x-ray energy dispersive analysis (EDAX), x-ray diffraction and optical transmission. The results showed for the films grown with the graphite source for Al evaporation, the Al did not incorporate in the CdTe matrix, at least to the level of EDAX sensitivity; they maintained the same crystal structure and band gap. For the samples grown with the tantalum source, we were able to incorporate the Al. The x-ray diffraction patterns show that the films have a crystal structure that depends on Al concentration. They were cubic up to 2.16 at. % Al concentration; for 19.65 at. % we found a mixed phase; for Al concentration higher than 21 at. % the films were amorphous. For samples with cubic structure it was found that the lattice parameter decreases and the band gap increases with Al concentration. (Author)

  12. Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy

    Directory of Open Access Journals (Sweden)

    Liming Liu

    2014-02-01

    Full Text Available Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by α-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 μm-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated.

  13. Direct laser cooling Al+ ions optical clocks

    CERN Document Server

    Zhang, J; Luo, J; Lu, Z H

    2016-01-01

    Al$^+$ ions optical clock is a very promising optical frequency standard candidate due to its extremely small blackbody radiation shift. It has been successfully demonstrated with indirect cooled, quantum-logic-based spectroscopy technique. Its accuracy is limited by second-order Doppler shift, and its stability is limited by the number of ions that can be probed in quantum logic processing. We propose a direct laser cooling scheme of Al$^+$ ions optical clocks where both the stability and accuracy of the clocks are greatly improved. In the proposed scheme, two Al$^+$ ions traps are utilized. The first trap is used to trap a large number of Al$^+$ ions to improve the stability of the clock laser, while the second trap is used to trap a single Al$^+$ ions to provide the ultimate accuracy. Both traps are cooled with a continuous wave 167 nm laser. The expected clock laser stability can reach $9.0\\times10^{-17}/\\sqrt{\\tau}$. For the second trap, in addition to 167 nm laser Doppler cooling, a second stage pulsed ...

  14. MOSQUE ARCHITECTURE AS A SUSTAINABLE BUILDING IN URBAN (Case Study: Al Markas Al Islamic Mosque Makassar

    Directory of Open Access Journals (Sweden)

    Imriyanti Imriyanti

    2014-02-01

    Full Text Available Abstract Mosque Architecture is a part of Islamic architecture. Mosque should be fused with elements of nature because its function as a place to pray to God who created the universe. Al Markas Al Islamic Makassar mosque is used as a center of Islamic aspirations of the people and the government to accommodate all the activities of moslems in Makassar. Through this function, the provision of Al Markas Al Islamic mosque began from the desire of Islamic societies in Makassar, which wants the Islamic center to be equipped with facilities and infrastructure as well as architectural, monumental buildings and structures that can be last for hundreds of years (continuous, blend with the environment, and also can be used by the public. Having regard to the function of a mosque especially at the Al Markas Al Islamic Makassar mosque, then the problem that arise is how the Al Markas Al Islamic mosque can be survived/sustainable  in order  to function  as a place  of worship  and  as a center  of Islam.  This research  is a descriptive qualitative research that is trying to generate data in the form of systematic and accurate picture of the object of study. The sustaiprophetlity  of Al Markas AL Islamic mosque can be known through the concept of Islam  in accordance with the view of Islam as well as the sustaiprophetlity of the buildings that seen in the spatial pattern of the mosque, appearance, natural lighting, natural ventilation, and user behavior of the mosque. Keywords: mosque architecture, sustaiprophetlity, view of Islam     Abstrak Arsitektur masjid merupakan bagian dari arsitektur Islam. Bangunan masjid sebaiknya dapat menyatu dengan unsur alam karena masjid difungsikan sebagai wadah dalam bersujud/sembahyang  kepada Allah SWT yang menciptakan alam semesta ini. Masjid Al Markas Al Islamic Makassar merupakan kompleks kegiatan Islam yang digunakan sebagai pusat aspirasi masyarakat  dan pemerintahan  yang dapat menampung

  15. ‘Uluww al-Isnad dalam Periwayatan Hadis Abu Muhammad al-Husain bin Mas‘ud al-Baghawi

    Directory of Open Access Journals (Sweden)

    Romlah Abubakar Askar

    2016-05-01

    Full Text Available Abu Muhammad al-Husayn Ibnu Mas’ud al-Baghawi (450-516H was one of the leading scholars in Tafsir (Quran exegesis, hadith (prophetic tradition, and fiqh (Islamic legal jurisprudence in his era. He was categorized as muta’akhirūn (scholars who came later on and was instrumental in the development of these three disciplines. In the field of exegesis, he was among the scholars who used al-Ma’tsūr, (commentary stylist, relying on the verses of the Qur’an, hadith, and the statements from the followers of the tabi’īn (the followers of the followers. This can be found in his recorded work Ma’ālim al Tanzīl. In the field of hadith, he preserved the narration method and presenting a new approach by merging some patterns of hadith narration from several books of hadith in his work known as ṭarīqah al-Jam’u (combination [amalgamation] method. This pattern will not occur unless there is the existence of other transmission lines as a second chain of narration used to produce ‘uluww al-Isnād (the noble sanad or nuzūl al-Isnād (descent sanad. It is recorded in his works: al-Jam’u baina al-Ṣaḥīḥain, Sharḥ al-Sunnah and Maṣābiḥ al-Sunnah. In the field of Jurisprudence, he was amongst those mujtahidin from the Shafiee school of thought, recorded in his Majmū’ ‘al-Fatāwā, al-Kifāyah fī al-Furū’ and Kitāb al-Tahdzīb. This paper aims to examine one of al-Baghawi’s skills in sanad collection which is the uluww al-isnād and nuzūl al-isnād, recorded from his two works Ma’ālim al-Tanzīl and Syarḥ al-Sunnah. The quantitative, qualitative and comparative approach has been used in this study to give an authentic description of the terms ‘uluww al-isnād, nuzūl al-isnād from al-Baghawi. Studies have found there are many examples of uluww al-Isnād and nuzūl al-isnāds contained in the patterns of al-Baghawi’s chain of narration towards the Ṣaḥīḥayn of al-Bukhari and Muslim as the mustakhrij

  16. Autologous Stem Cell Transplant for AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Vivek Roy

    2012-01-01

    Full Text Available AL amyloidosis is caused by clonal plasma cells that produce immunoglobulin light chains which misfold and get deposited as amyloid fibrils. Therapy directed against the plasma cell clone leads to clinical benefit. Melphalan and corticosteroids have been the mainstay of treatment for a number of years and the recent availability of other effective agents (IMiDs and proteasome inhibitors has increased treatment options. Autologous stem cell transplant (ASCT has been used in the treatment of AL amyloidosis for many years. It is associated with high rates of hematologic response and improvement in organ function. However, transplant carries considerable risks. Careful patient selection is important to minimize transplant related morbidity and mortality and ensure optimal patient outcomes. As newer more affective therapies become available the role and timing of ASCT in the overall treatment strategy of AL amyloidosis will need to be continually reassessed.

  17. Analyse de Viaje al pasado: los aztecas

    OpenAIRE

    Denis Lucchinacci

    2005-01-01

    1. Présentation du logiciel Viaje al pasado: los aztecas (el perfecto simple y el imperfecto en la narración y la descripción) a été conçu par Annie Desnoyers, linguiste à l'université de Montréal et Matilde Asencio, enseignante au Cégep du Vieux Montréal (Collège d'enseignement général et professionnel []), pour un public d'étudiants d'Espagnol Langue Étrangère (ELE). Disponible en deux versions - en ligne et sous forme de cédérom -, il s'agit d'un exerciseur destiné à la pratique du passé e...

  18. Analyse de Viaje al pasado: los aztecas

    Directory of Open Access Journals (Sweden)

    Denis Lucchinacci

    2005-11-01

    Full Text Available 1. Présentation du logiciel Viaje al pasado: los aztecas (el perfecto simple y el imperfecto en la narración y la descripción a été conçu par Annie Desnoyers, linguiste à l'université de Montréal et Matilde Asencio, enseignante au Cégep du Vieux Montréal (Collège d'enseignement général et professionnel [], pour un public d'étudiants d'Espagnol Langue Étrangère (ELE. Disponible en deux versions - en ligne et sous forme de cédérom -, il s'agit d'un exerciseur destiné à la pratique du passé e...

  19. Thermal Properties of Al-50%Si Alloys

    Institute of Scientific and Technical Information of China (English)

    Akio Nishimoto; Katsuya Akamatsu; Kazuyoshi Nakao; Kazuo Ichii

    2004-01-01

    In order to prepare a hypereutectic Al-Si alloy with low coefficients of thermal expansion (CTE), Al-50was produced by powder metallurgy (P/M) and ingot metallurgy (I/M). P/M specimen was prepared by mechanical alloying(MA) and pulsed electric-current sintering (PECS). The microstructures of specimens were characterized by optical microscopy and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS). Vickers microhardness and CTE measurements were performed. The grains in the P/M specimen were refined with increasing MA time. Primary Si and eutectic Si in the I/M specimen were remarkably refined by adding minute amounts of Sr. The CTE of P/M and I/M specimens were estimated as 7.8×10-6 and 10.7×10-6, respectively. These values were as same as a CTE of Al2O3 ceramics.

  20. Del sombrero al árbol. Relatos icónicos de la nación colombiana

    Directory of Open Access Journals (Sweden)

    González Aranda, Beatriz

    2009-12-01

    ó debido a la declaración de Independencia. Una obra de autor anónimo puede considerarse como la representación de la ceremonia de la siembra del árbol. Se analiza el tránsito tan arraigado del concepto de patria, a su desprestigio y en la actualidad, a su reivindicación. El tercer episodio narra de cómo llegó a convertirse en icono el Poporo quimbaya, entre las cerca de 33.600 piezas del Museo del Oro del Banco de la República. Su forma geométrica, el material y mito de El Dorado, contribuyeron a su iconización. El cuarto episodio trata de la Virgen de Chiquinquirá (La Chinca (1556 vinculada al milagro de la renovación en la sociedad colonia. Se conecta la colonia con la independencia, la devoción con la nacionalidad. Se concluye con una pregunta sobre ¿Quién crea las representaciones de la nacionalidad, el artista, el pueblo, los museos? y sobre la validez de las representaciones iconográficas.

  1. [Al-Biruni--a universal scientist].

    Science.gov (United States)

    Kujundzić, E; Masić, I

    1999-01-01

    Al-Biruni's was of Persian descent. He was born in Horesmiya and had studied mathematics, history and medicine. Acquiring knowledge from these sciences, he wrote an outstanding work on chronology of several nations and devoted it to Ziyarit ruler Kabus. He made a chronological overview of calendars from many nations, including Persians, Greeks, Egyptians, Jews, Melkitian and Nestorian Christians, Sabeyaans as well as the old Arabs. Data presented in the work, according to the later authors, were taken from very reliable sources. He was contemporary of Ibn-Sina, and thanks to their friendship, they have discussed very much miscellaneous topics. He belonged to the group of scholars, taken by Gaznevian Soultan Mahmud to a long journey to India. Afterwards Al-Biruni wrote and published detailed work "Description of India"--a work on cultural history of India. Due to excellent abilities of Al-Biruni as a philosopher and scholar, there are still significant and reliable notes about buddhistic philosophy, structure of castes and Brahmans' life style. In this Al-Biruni's masterpiece, there are many comparative analysis of Suffism and certain Indian philosophical methods. Al-Biruni's most important work is "Pharmacopoeia"--"Kitab al-saydala", which brilliantly describes all medicaments. This work has been published in many languages. He also wrote few works on astronomy and astrology. In those works he has explained some astrological events through scientific approach in a such peculiar way that nobody has ever explained before. He was also interested in sciences like geology, mineralology, geography, mathematics, psychology and many others.

  2. Kritik Terhadap Pemikiran Tasawuf Al-Raniri

    Directory of Open Access Journals (Sweden)

    Syaifan Nur

    2013-12-01

    Full Text Available Abstract : Al-Raniri is often positioned by some scholars as “superior” figure, which is contrasted to Hamzah Fansuri and Syamsuddin Sumaterani, and that is why they predicate him as one of pioneer of Islamic reformer in Malay- Indonesian archipelago. Anti-wujūdiyyah Sufism campaign by al-Raniri quite successful to some extent to amputate the rate of development of philosophical Sufism was brought by Fansuri and Sumaterani in the one hand, and strike off the nature of moral Sufism in the other, redeemed by bloodshed. This article discussed the “superiority” of al-Raniri’s thought of Sufism, viewed from a broader spectrum, either in relation to problems of faith or theology and politics surrounding the circumstance of his time.Keywords : Philosophical tasawuf, neo-sufism, panteism, tajalli, God’s attributeAbstrak : Al-Raniri oleh banyak kalangan seringkali diposisikan sebagai tokoh “superior” yang diperlawankan dengan Hamzah Fansuri dan Syamsuddin Sumaterani, dan itu sebabnya para ahli memberinya predikat sebagai seorang pelopor pembaru (mujaddid Islam di Nusantara. Anti tasawuf wujūdiyyah yang dikampanyekan oleh al-Raniri cukup berhasil mengamputasi laju perkembangan tasawuf falsafi yang dibawa oleh Fansuri dan Sumaterani di satu sisi, dan melancarkan laju corak tasawuf akhlaki di sisi lain, yang ditebus dengan cara pertumpahan darah. Tulisan ini mendiskusikan “superioritas” pemikiran tasawuf al-Raniri tersebut, dilihat dari spektrum yang lebih luas, baik menyangkut persoalan keyakinan atau teologi maupun politik yang mengitari situasi zamannya.Kata kunci : Tasawuf falsafi , neo-sufisme, panteisme, tajalli, sifat Tuhan

  3. Inspección de piezas 3D: revisión de la literatura

    Directory of Open Access Journals (Sweden)

    Andrés Eleázar Jaramillo

    2010-04-01

    Full Text Available A survey of inspection systems using range images is presented; the review focus especially on papers published from 2000 to 2006. The inspection systems are classified according to the techniques used in the acquisition stage. The specific applications of inspection considered in the mentioned works are described, as well as the most outstanding characteristics of systems developed to date. Tendencies in such developments are identified from these characteristics, such as the search for increased CAD-model based flexibility and the preferential use of active triangulation systems (especially projecting structured light as a light plane and fringes instead of passive systems. The problem of inspecting deformable pieces is then presented, representing an open topic for considering developing future systems. The more relevant works related to this topic are also discussed.

  4. El Componente Dramatico-musical en una pieza breve de Melchor Fernandez de Leon

    Directory of Open Access Journals (Sweden)

    Elisa Dominguez de Paz

    2011-12-01

    Full Text Available Music played an outstanding role in seventeenth-century Spanish court theatre, even to the point of being a factor when considering whether the plays were to be staged in the royal palace or staged only in the popular theatres or corrales. But it was in the royal playhouses where a number of new musical-dramatic new genres developed. In other words, different types of plays were characterized by their musical components, as in for example, El baile de las aves [The Dance of the Birds] by Melchor Fernández de León, a text that was first staged in the Royal Palace in 1684, on occasion of the birthday of Queen María Luisa, wife to King Carlos II. Music, dancing and singing contribute greatly to turn the representation of the play into a very brilliant event.

  5. Epigenética nutricional: una pieza clave en el rompecabezas de la obesidad

    OpenAIRE

    2010-01-01

    La obesidad es el resultado de la interacción de la genética con factores dietéticos y estilos de vida. La nutrigenómica estudia la influencia de la nutrición y los nutrientes en la expresión génica. Actualmente, como punto de vista complementario, surge la epigenética, centrada en los mecanismos que regulan la expresión del ADN sin alterar su secuencia de nucleótidos.

  6. Optimización del stock de piezas de repuesto para equipos médicos

    Directory of Open Access Journals (Sweden)

    Zoila Esther Morales Tabares

    2015-04-01

    Full Text Available One of the most common problems for warehouse management is the spare parts stock planning to cover the repair and maintenance needs of medical equipment. At the Center for Clinical and Electro Engineering, the planning of spare parts for maintenance and replacement is carried out through reports issued by electromedical who work the health areas of the country. Nowadays the recorded information, plus expert judgment is not enough for carrying out an optimum planning that would supply the correct amount of parts demanded, in an adequate period of time. Taking into account these insufficiencies this paper presents an algorithm that allows the optimization of the stock of spare parts for medical equipment. For its conformation, statistics estimation techniques were used: Stratified Random Sampling, Correlation and Simple Linear Regression.

  7. Conservacion de piezas anatomicas en seco mediante el metodo de prives

    Directory of Open Access Journals (Sweden)

    Flavio Correa Alarcón. Profesor Consultante .

    2005-05-01

    Full Text Available [...Los medios de enseñanza son apropiados para reducir el camino hacia el objetivo o enriquecerlo con relación con su contenido. De acuerdo con el rápido y continuo desarrollo de la revolución científico técnica de nuestro tiempo, el proceso docente educativo requiere de métodos, procedimientos y medios de enseñanza capaces de absorber el mayor número posible de conocimientos para hacerlo llegar a los estudiantes.-La calidad de un medio es dado por el mayor número de receptores que estimula. Demostrar y observar los objetos originales en la clase, tiene como ventaja en que los alumnos pueden dedicarle toda su atención, sin embargo, tienen el inconveniente de no poderlos conservar u forma original una vez preparados se deterioran fácilmente, pierden sus características morfológicas y pueden dar una información tergiversada a los alumnos....

  8. Acción de los desinfectantes en piezas tratadas endodónticamente

    OpenAIRE

    Santángelo, Georgina; Bertola, N.; Piantanida, I.; Hervit, M.; Domench, A. L.; Polo, F.

    2015-01-01

    La patogenia de la pulpa dental y de los tejidos periapicales depende en gran medida de las bacterias, por lo que es necesario conocer las situaciones que permiten a los microorganismos sobrevivir o prevalecer dentro del sistema de conductos radiculares y su medio y así mejorar el criterio clínico en el tratamiento de las infecciones pulpares y de las regiones de influencia. Descripción del caso: Se realizó un estudio comparativo para analizar la eficiencia de la desinfección del sistema de c...

  9. La danza como pieza constructora de la identidad griega en Buenos Aires

    OpenAIRE

    Medella, Cecilia Eleonora

    2009-01-01

    Esta investigación se plantea interrogantes sobre la construcción identitaria de la colectividad griega del barrio de Palermo, en Buenos Aires, a partir del análisis de discursos, prácticas actuales que se vinculan directamente con la experiencia vivida por ese grupo, como las danzas, la gastronomía, etcétera. Se parte de considerar a la construcción identitaria como una representación, un discurso particular e histórico, relacional, por lo cual es plausible reconstruir la identidad de un gru...

  10. Fabrication of Al-Al3Ti/Ti3Al Functionally Graded Materials under a Centrifugal Force

    Directory of Open Access Journals (Sweden)

    Yoshimi Watanabe

    2010-09-01

    Full Text Available Fabrication of Al-Al3Ti functionally graded materials (FGMs under the centrifugal force has recently attracted some attention. The controlled compositional gradient of the fabricated FGMs, the low cost of the process, and the good mold filling, are the main advantages of the centrifugal method (CM. Using the conventional CM techniques such as the centrifugal solid-particle method and centrifugal in-situ method, FGMs rings with gradually distributed properties could be achieved. As a more practical choice, the centrifugal mixed-powder method (CMPM was recently proposed to obtain FGMs containing nano-particles selectively dispersed in the outer surface of the fabricated parts. However, if a control of the particles morphology, compound formulas or sizes, is desired, another CM technique is favored. As a development of CMPM, our novel reaction centrifugal mixed-powder method (RCMPM has been presented. Using RCMPM, Al‑Al3Ti/Ti3Al FGMs with good surface properties and temperature controlled compositional gradient could be achieved. In this short review, this novel method will be discussed in detail and the effect of RCMPM processing temperature on the reinforcement particles morphology, size and distribution through the fabricated samples, will be reviewed.

  11. Total energy, equation of state and bulk modulus of AlP, AlAs and AlSb semiconductors

    Indian Academy of Sciences (India)

    A R Jivani; H J Trivedi; P J Gajjar; A R Jani

    2005-01-01

    Recently proposed model potential which combines both linear and quadratic types of interactions is employed for the investigation of some properties like the total energy, equation of state and bulk modulus of AlP, AlAs and AlSb semiconductor compounds using higher-order perturbation theory. The model potential parameter is determined using zero pressure condition. The ratio of the covalent bonding term E cov to the second-order term 2 is 6.77% to 11.85% which shows that contribution from higher order terms are important for zinc-blende-type crystals. The calculated numerical results of the total energy, energy band gap at Jones-zone face and bulk modulus of these compounds are in good agreement with the experimental data and found much better than other such theoretical findings. We have also studied pressure–volume relations of these compounds. The present study is carried out using six different screening functions along with latest screening function proposed by Sarkar et al. It is found from the present study that effect of exchange and correlation is clearly distinguishable.

  12. Semantische Merkmale als Mittel der Textkonstitution

    Directory of Open Access Journals (Sweden)

    Stojan Bračič

    2008-12-01

    Full Text Available Im folgenden Beitrag sollen semantische Relationen unter die Lupe genommen werden, die im text dazu beitragen, dass einzelne Textkomponenten miteinander verknüpft werden. Dabei geht es hauptsächlich um Relationen, die nicht satzthematisch sind - diese sind nämlich als textuelle Koreferenzketten ausreichend untersucht worden (vgl. u.a. Bračič/Fix/Greule 2007 - sondern um jene Relationen, die als Prädikationen einzelner textgrammatischer Einheiten (Sätze vorkommen und ebenfalls gewisse geordnete Strukturierungen aufweisen.

  13. Aspectos biopsicosociales asociados al embarazo adolescente

    OpenAIRE

    2012-01-01

    Introducción: El embarazo en la adolescencia, es un evento inesperado, sorpresivo. Este artículo establece la importancia de identificar los aspectos biopsicosociales asociados al embarazo adolescente en las embarazadas asistentes al programa de Control Prenatal de una Empresa Social del Estado de nivel 1 en Montería en 2009, para comprender las actitudes y los comportamientos asociados a esta etapa tan temprana. Materiales y Métodos: Es un estudio descriptivo, cuantitativo, de corte transver...

  14. The wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

    Moser, Jakob Maximilian; Bigini, Paolo; Schmitt-John, Thomas

    2013-01-01

    This review article is focused on the research progress made utilizing the wobbler mouse as animal model for human motor neuron diseases, especially the amyotrophic lateral sclerosis (ALS). The wobbler mouse develops progressive degeneration of upper and lower motor neurons and shows striking...... the disease mechanism and testing various therapeutic approaches and discuss the relevance of these advances for human ALS. The identification of the causative mutation linking the wobbler mutation to a vesicle transport factor and the research focussed on the cellular basis and the therapeutic treatment...

  15. Simulations of the premelting of Al(110)

    DEFF Research Database (Denmark)

    Stoltze, Per

    1990-01-01

    The premelting of Al(110) is studied by molecular dynamics simulations using the potential for Al derived from effective medium theory. We find a progressive disordering of the surface region as the bulk melting point is approached. This disorder is mediated by the formation of adatom–vacancy pairs....... Based on the calculated radial distribution function and the analytical expression for the energy, it is demonstrated that the thermodynamics of disorder and melting is reflected in the single particle properties by a decrease in the number of nearest neighbors. The Debye temperature for the surface...

  16. Del Derecho laboral al Derecho del trabajo

    OpenAIRE

    Jaramillo Jassir, Ivan Daniel

    2011-01-01

    El Derecho Laboral hijo de la revolución industrial, calificado como el acontecimiento jurídico del siglo XX, reduce su ámbito de estudio al trabajo subordinado. Los cambios del sistema de producción superan la centralidad del contrato de trabajo subordinado a tiempo indeterminado, situación que demanda ampliación del ámbito de aplicación subjetivo y objetivo de la materia, dando paso al Derecho del Trabajo que se ocupa del trabajo en todas sus modalidades como fuente de ingreso para satisfac...

  17. Nuestra labor de mirar al otro

    OpenAIRE

    Campos Saborío, Natalia

    2016-01-01

    El estudio etnográfico que dio origen al libro que hoy presentamos, se tituló la "Etnografía del cambio educativo en el ámbito de la investigación social". Una de sus misiones fue buscar al otro, entendiéndose el otro, de aquí en adelante como director, directora, docentes, niños y niñas y padres de familia de la escuela #1, como la llamamos en la investigación antes citada.

  18. Magnetic Properties of NdAl2

    DEFF Research Database (Denmark)

    Bak, P.

    1974-01-01

    The magnetic properties of NdAl2 are calculated using a Hamiltonian including crystal-field and isotropic exchange interaction terms. A two-dimensional mean-field theory is evaluated to calculate single-crystal magnetization curves. It is shown that the magnetic properties can be understood using...... the crystal-field parameters derived from the magnetic exciton spectrum measured by Houmann et al. by means of inelastic neutron scattering. The combined lambda -Schottky anomaly in the heat capacity is explained. No additional parameters are introduced....

  19. Vibrations on Al surfaces covered by sodium

    Science.gov (United States)

    Rusina, G. G.; Eremeev, S. V.; Borisova, S. D.; Sklyadneva, I. Yu.; Chulkov, E. V.

    2006-09-01

    In this paper we present the results of a comparative study of vibrational and structural properties of the ordered (√{3}×√{3})R30∘ and c(2 × 2) phases formed by Na adatoms at room temperature on the Al(1 1 1) and Al(1 0 0) surfaces, respectively. The surface relaxation, surface phonon dispersion, and polarization of vibrational modes are calculated using the embedded-atom method. Our calculated structural parameters are in agreement with experimental and ab initio results. The obtained vibrational frequencies compare fairly well with available experimental data.

  20. Metamagnetism in Ce(Ga,Al)2

    Indian Academy of Sciences (India)

    K G Suresh; S Radha; A K Nigam

    2002-05-01

    Effect of Al substitution on the magnetic properties of Ce(Ga1-Al)2 ( = 0, 0.1 and 0.5) system has been studied. The magnetic state of CeGa2 is found to be FM with a C of 8 K, whereas the compounds with =0.1 and 0.5 are AFM and possess N of about 9 K. These two compounds undergo metamagnetic transition and the critical fields are about 1.2 T and 0.5 T, respectively at 2 K. These variations are explained on the basis of helical spin structure in these compounds.

  1. Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The performance of Al-Ti-C master alloy in refining Al-10Mg and A1-5Cu alloys was studied by using electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD) analysis.The results indicate that there are obvious fading phenomena in both Al-10Mg and Al-5Cu alloys with the addition of Al-5Ti-0.4C refiner which contains TiC and TiAl3 compounds.Mg element has no influence on the stability of TiC and TiAl3, while TiC particles in Al-10Mg alloy react with Al to form Al4C3 particles, resulting in the refinement fading.However, TiC particles are relatively stable in Al-5Cu alloy, while TiAl3 phase reacts with Al2Cu to produce a new phase Ti(Al, Cu)2, which is responsible for the refinement fading in Al-5Cu alloy.These indicate that the refinement fading will not occur only when both the TiC particles and TiAl3 compound of Al-Ti-C refiner are stable in Al alloys.

  2. Directional Solidification and Mechanical Properties of NiAl-NiAlTa Alloys

    Science.gov (United States)

    Johnson, D. R.; Chen, X. F.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.

    1995-01-01

    Directional solidification of eutectic alloys is a promising technique for producing in-situ composite materials exhibiting a balance of properties. Consequently, the microstructure, creep strength and fracture toughness of directionally solidified NiAl-NiAlTa alloys were investigated. Directional solidification was performed by containerless processing techniques to minimize alloy contamination. The eutectic composition was found to be NiAl-15.5 at% Ta and well-aligned microstructures were produced at this composition. A near-eutectic alloy of NiAl-14.5Ta was also investigated. Directional solidification of the near-eutectic composition resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The off-eutectic alloy exhibited promising compressive creep strengths compared to other NiAl-based intermetallics, while preliminary testing indicated that the eutectic alloy was competitive with Ni-base single crystal superalloys. The room temperature toughness of these two-phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa.

  3. Electronic states and spin-forbidden cooling transitions of AlH and AlF.

    Science.gov (United States)

    Wells, Nathan; Lane, Ian C

    2011-11-14

    The feasibility of laser cooling AlH and AlF is investigated using ab initio quantum chemistry. All the electronic states corresponding to the ground and lowest two excited states of the Al atom are calculated using multi-reference configuration interaction (MRCI) and the large AV6Z basis set for AlH. The smaller AVQZ basis set is used to calculate the valence electronic states of AlF. Theoretical Franck-Condon factors are determined for the A(1)Π→ X(1)Σ(+) transitions in both radicals and found to agree with the highly diagonal factors found experimentally, suggesting computational chemistry is an effective method for screening suitable laser cooling candidates. AlH does not appear to have a transition quite as diagonal as that in SrF (which has been laser cooled) but the A(1)Π→ X(1)Σ(+) transition transition of AlF is a strong candidate for cooling with just a single laser, though the cooling frequency is deep in the UV. Furthermore, the a(3)Π→ X(1)Σ(+) transitions are also strongly diagonal and in AlF is a practical method for obtaining very low final temperatures around 3 μK.

  4. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    Energy Technology Data Exchange (ETDEWEB)

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  5. Electronic circuits having NiAl and Ni{sub 3}Al substrates

    Energy Technology Data Exchange (ETDEWEB)

    Deevi, S.C.; Sikka, V.K.

    1999-10-12

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni{sub 3}Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  6. Muslih b. `Abd al-Rahman al-Maraqî : Muslikh of Mranggen

    NARCIS (Netherlands)

    Bruinessen, M.M. van

    2007-01-01

    MUSLIH b. `ABD AL-RAHMAN AL-MARAQÎ (KH. Muslikh of Mranggen) [Indonesia; 1917-1981] [Dictionnaire biographique des savants et grandes figures du monde musulman périphérique, du XIXe siècle à nos jours, Fasc. no 2. Paris: CNRS-EHESS, 1998, p. 23-24] One of the most influential Javanese teachers of t

  7. Fabrication and Characterization of AL-AL4C3 Nanocomposite by Mechanical Alloying

    Science.gov (United States)

    Mohammad Sharifi, E.; Enayati, M. H.; Karimzadeh, F.

    Aluminum carbide (Al4C3) seems to be an ideal reinforcement for producing aluminum matrix composites. Al4C3 has high hardness and shear strength as well as a high melting point. The dispersion of Al4C3 particles in the matrix produces a pinning effect that reduces aluminum grain growth, which improves the mechanical properties. In this study, aluminum powders were mixed with 4.5 wt.% graphite and mechanically alloyed using a high-energy ball mill in order to produce Al-Al4C3 nanocomposite. The structural evaluation of powder particles after different milling times was studied by X-ray diffractometry, scanning electron microscopy and microhardness measurements. The aluminum crystallite size estimated with broadening of XRD peaks by Williamson-Hall formula. XRD results suggested that the grain size of aluminum decreased to nanometer range (30 nm) during ball milling. No Al4C3 formed during the mechanical alloying process. Milled powders were then annealed at 300-600 °C for 1 h under argon atmosphere. Annealing at temperatures higher than 300 °C led to formation of Al4C3 phase which increased as annealing temperature increased. Aluminum grain size remained in nanometer range after annealing process. The microhardness of powder particles increased after annealing. Both effects are due to the formation of nanosized Al4C3 particles.

  8. Sintering Behavior of CNT Reinforced Al6061 and Al2124 Nanocomposites

    Directory of Open Access Journals (Sweden)

    Nouari Saheb

    2014-01-01

    Full Text Available Ball milling and spark plasma sintering were successfully used to produce carbon nanotube reinforced Al6061 and Al2124 nanocomposites which have potential applications in the fields of aerospace, automotive, electronics, and high precision instrumentation. Al2124 and Al6061 nanocomposite powders containing 0.5 to 2 wt.% CNTs prepared through sonication and wet ball milling were spark plasma sintered at 400, 450, and 500°C for 20 minutes under a pressure of 35 MPa. CNTs were better dispersed, and less agglomerated and had good adhesion to the matrix in composites containing 1 wt.% CNTs. The increase of CNT content to 2 wt.% led to the formation of CNT clusters which resulted in less uniform and homogenous composite powders. Almost full densification of Al6061 reinforced with CNTs was achieved at 500°C. Also, CNTs reinforced Al2124 nanocomposites reached very high densities at 500°C. Composites reinforced with 1 wt.% CNTs displayed better densification compared to composites containing 2 wt.% CNTs. The increase of CNTs content from 0.5 to 1 wt.% increased the hardness of the Al6061 and Al2124 alloys to maximum values. Further increase of CNTs content to 2 wt.% decreased the hardness to values lower than that of the monolithic alloys.

  9. Thermodynamic Assessments of Al-In-Sb and Al-In-As Systems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The experimental thermodynamic and phase diagram data of the Al-In-Sb and Al-In-As ternary systems were critically assessed.A set of self-consistent thermodynamic model parameters were obtained to describe the phase equilibria and the thermodynamic properties of two systems.In most cases,the calculated values agree very well with the experimental data.

  10. Synthesis of TiAl-Ti2AlN composites by in-situ crystallization

    Institute of Scientific and Technical Information of China (English)

    ZHU Jian-feng; GAO Ji-qiang; WANG Fen

    2006-01-01

    The amorphization process during mechanical alloying (MA) was investigated for the Ti-50%/Al (mole fraction) powder mixtures with no special protection conditions. During the milling process, with the milling time prolonging, the metallic powder Ti and Al were finely mixed, gradually, aluminum completely dissolved into titanium to form an Ti(Al) hcp supersaturated solid solution, and finally, transformed to the amorphous phase after milled for about 39 h. As a result of heat treatment in hot press sintering processing for the mechanically alloyed amorphous powders in vacuum, a submicrostructure intermetallics of TiAl/Ti2AlN composite can be produced by in-situ crystallization. Furthermore, the structure evolution, phase formation and transformation during the heat treatment were also investigated by X-ray diffractometry and differential thermal analysis. The results show that the reaction involves many transitional stages, including formation of TiAl3 and transformation into TiAl and Ti3Al. The examination show that the composite materials fabricated by this in-situ crystallization from amorphization have good mechanical properties due to fine grain size and uniform microstructure.

  11. MgAl2O4–-Al2O3 solid solution interaction: mathematical framework and phase separation of -Al2O3 at high temperature

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2011-07-01

    Although existence of MgAl2O4–-Al2O3 solid solution has been reported in the past, the detailed interactions have not been explored completely. For the first time, we report here a mathematical framework for the detailed solid solution interactions of -Al2O3 in MgAl2O4 (spinel). To investigate the solid solubility of -Al2O3 in MgAl2O4, Mg–Al spinel (MgO–Al2O3; = 1, 1.5, 3, 4.5 and an arbitrary high value 30) precursors have been heat treated at 1000°C. Presence of only non-stoichiometric MgAl2O4 phase up to = 4.5 at 1000°C indicates that alumina (as -Al2O3) present beyond stoichiometry gets completely accommodated in MgAl2O4 in the form of solid solution. → alumina phase transformation and its subsequent separation from MgAl2O4 has been observed in the Mg–Al spinel powders ( > 1) when the 1000°C heat treated materials are calcined at 1200°C. In the mathematical framework, unit cell of MgAl2O4 (Mg8Al16O32) has been considered for the solid solution interactions (substitution of Mg2+ ions by Al3+ ions) with -Al2O3. It is suggested that combination of unit cells of MgAl2O4 takes part in the interactions when > 5 (MgO–Al2O3).

  12. FABRICATION OF Al/Al2O3 FGM ROTATING DISC

    Directory of Open Access Journals (Sweden)

    A. B. Sanuddin

    2012-06-01

    Full Text Available This study presents a method of fabricating a disc made of Al/Al2O3 functionally graded materials (FGM, using a powder metallurgy manufacturing process. The aim is to develop a processing method for a rotating disc made of FGM, by stacking the slurry, layer by layer in a radial direction. A three-layer functionally graded material of Al/Al2O3 is fabricated with compositions of 10, 20, 30 vol.% Al2O3. The ceramic composition increases from the discs inner (centre to the outer. The combination of these materials can offer the ability to withstand high temperature conditions whilst maintaining strength in extreme environments.

  13. The anodic and cathodic dissolution of Al and Al-Cu-Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mokaddem, M.; Volovitch, P. [Laboratoire de physicochimie des surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11, rue Pierre et Marie Curie, Paris (France); Rechou, F.; Oltra, R. [Institut CARNOT de Bourgogne, Electrochimie Interfaciale-Corrosion, UMR5209, Universite de Bourgogne, Dijon (France); Ogle, K., E-mail: kevin-ogle@enscp.f [Laboratoire de physicochimie des surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11, rue Pierre et Marie Curie, Paris (France)

    2010-04-15

    Atomic emission spectroelectrochemistry (AESEC) was used to monitor the release of Al from 99.99% aluminum (1199 alloy) and Al, Mg, and Cu from 2024 Al alloy in 30 g/l NaCl electrolyte as a function of pH. The cathodic dissolution of Al was demonstrated and attributed to an increase in the pH at the interface due to the water reduction reaction. The dissolution of Mg was also observed but was a more complex function of current probably depending on the interfacial pH and the Al dissolution rate. The detachment of copper-rich particles was observed as very rapid spectroscopic emission transients (peak width < 10 ms).

  14. Hydrogenation properties of Mg-Al alloys

    DEFF Research Database (Denmark)

    Andreasen, Anders

    2008-01-01

    to disproportionation with the formation of magnesium hydride and metallic aluminum as the final product. Experimental evidence renders this process reversible. It is observed that the enthalpy of hydride formation of magnesium is lowered upon alloying with Al due to a slightly endothermic disproportionation reaction...

  15. The Science of al-Biruni

    CERN Document Server

    Sparavigna, Amelia Carolina

    2013-01-01

    Al-Biruni (973-1048) was one of the greatest scientists of all times. He was an astronomer, mathematician and philosopher, and studied physics and natural sciences. In this paper, we will discuss some of his experimental methods and some instruments he used.

  16. Control al doping Compromiso de Colombia

    Directory of Open Access Journals (Sweden)

    Claudia Prieto

    2015-06-01

    Full Text Available Este documento da a conocer la importante noticia de la aprobación, por parte del Comité Olímpico Internacional (COl, de un laboratorio colombiano, para el control al doping, a la vez que aprovecha la oportunidad para ampliar alguna información sobre este tema.

  17. Niedermolekulare Verbindungen aus Spinnen als chemische Sensoren

    DEFF Research Database (Denmark)

    Olsen, Christian Adam; Kristensen, Anders S.; Strømgaard, Kristian

    2011-01-01

    sie als Leitstrukturen für die Entwicklung, Synthese und biologische Untersuchung synthetischer Analoga verwendet. Weit weniger erforscht sind hingegen Verbindungen, die der Kommunikation von Spinnen dienen. Vor kurzem wurden jedoch auf dem Gebiet der Pheromone und Allomone aus Spinnen neue...

  18. CALCULUL CINETOSTATIC AL MECANISMELOR PLANETARE CILINDRICE

    Directory of Open Access Journals (Sweden)

    Păun ANTONESCU

    2012-05-01

    Full Text Available În lucrare se prezintă o metodă analitică pentru calculul cinetostatic al mecanismului planetarmonomobil cu două roţi dinţate centrale. Se consideră mai întâi cazul general al schemelor cinematice cu douăroţi dinţate solidare tip satelit, în două variante practice (multiplicator şi reductor de turaţie. Este menţionatcazul particular al mecanismelor planetare cu o singură roată satelit cu angrenare dublă (exterioară şiinterioară. Pe baza modelului de analiză cinetostatică a mecanismului planetar monomobil cu două roţi dinţatecentrale, în finalul lucrării se abordează o problemă practică de calcul cinetostatic al unui mecanism planetarcilindric simplu folosit la capul de frezat pentru prelucrarea roţilor dinţate cilindrice cu dinţi curbi înhipocicloidă.

  19. Management of respiratory symptoms in ALS.

    LENUS (Irish Health Repository)

    Hardiman, Orla

    2011-03-01

    Respiratory insufficiency is a frequent feature of ALS and is present in almost all cases at some stage of the illness. It is the commonest cause of death in ALS. FVC is used as important endpoint in many clinical trials, and in decision-making events for patients with ALS, although there are limitations to its predictive utility. There are multiple causes of respiratory muscle failure, all of which act to produce a progressive decline in pulmonary function. Diaphragmatic fatigue and weakness, coupled with respiratory muscle weakness, lead to reduced lung compliance and atelectasis. Increased secretions increase the risk of aspiration pneumonia, which further compromises respiratory function. Bulbar dysfunction can lead to nutritional deficiency, which in turn increases the fatigue of respiratory muscles. Early recognition of respiratory decline and symptomatic intervention, including non-invasive ventilation can significantly enhance both quality of life and life expectancy in ALS. Patients with respiratory failure should be advised to consider an advance directive to avoid emergency mechanical ventilation.

  20. Management of respiratory symptoms in ALS.

    LENUS (Irish Health Repository)

    Hardiman, Orla

    2012-02-01

    Respiratory insufficiency is a frequent feature of ALS and is present in almost all cases at some stage of the illness. It is the commonest cause of death in ALS. FVC is used as important endpoint in many clinical trials, and in decision-making events for patients with ALS, although there are limitations to its predictive utility. There are multiple causes of respiratory muscle failure, all of which act to produce a progressive decline in pulmonary function. Diaphragmatic fatigue and weakness, coupled with respiratory muscle weakness, lead to reduced lung compliance and atelectasis. Increased secretions increase the risk of aspiration pneumonia, which further compromises respiratory function. Bulbar dysfunction can lead to nutritional deficiency, which in turn increases the fatigue of respiratory muscles. Early recognition of respiratory decline and symptomatic intervention, including non-invasive ventilation can significantly enhance both quality of life and life expectancy in ALS. Patients with respiratory failure should be advised to consider an advance directive to avoid emergency mechanical ventilation.

  1. Quantum Criticality in YFe2Al10

    Science.gov (United States)

    Gannon, William; Wu, Liusuo; Zaliznyak, Igor; Qiu, Yiming; Rodriguez-Rivera, Jose; Aronson, Meigan

    Quantum criticality has been studied in many systems, but there are few systems where observed scaling can be unified with a critical free energy F, or where the critical exponents form the basis for QC universality classes. We have identified a new layered material YFe2Al10 that shows remarkably strong QC behavior, where the scaling properties of the magnetic susceptibility and specific heat are consistent with the same F. Recent neutron scattering results paint a remarkable picture of the QC fluctuations in YFe2Al10. In contrast to classical transitions, where fluctuations are relatively long ranged and inelastic scattering is observed at a magnetic zone center, in YFe2Al10 the scattering is independent of wave vector in the critical plane, indicating that the fluctuations are spatially localized, while out of plane scattering indicates that the interplaner interactions are restricted to nearest neighbors. The dynamical susceptibility χ'' ~=E-2 , and is wholly temperature independent, indicating that E/T scaling is present, the signature of QC fluctuations. These results hint that the the criticality in YFe2Al10 is local, which until now has only been found in a few f-electron based compounds.

  2. Colombia frente al manejo del Presupuesto Nacional

    Directory of Open Access Journals (Sweden)

    Germán Enrique Reyes Forero

    2009-07-01

    Colombia pasa de 38 puntos en el 2007 a 46 puntos en el 2009, mejoría que no se corresponde con los múltiples escándalos de corrupción; ésta mejoría responde al manejo de tecnicismos como se intentará aclarar en el presente articulo.

  3. Creative Commons : Erfgoedinstelling als digitaal curator.

    NARCIS (Netherlands)

    Hoorn, Esther

    2008-01-01

    Zijn Creative Commons-licenties een ver-van-mijn-bed-show voor erfgoedinstellingen? Integendeel, betoogt Esther Hoorn. De instellingen kunnen ze gebruiken als ze rechthebbende zijn. Maar belangrijker nog: door het gebruik van deze licenties te stimuleren kunnen ze een spin in het web van netwerken r

  4. Silicon Strengthened CrAlVN Coatings

    Institute of Scientific and Technical Information of China (English)

    Qiang LI; Yue-xiu QIU; Bo LI; Dong-liang ZHAO; De-en SUN; De-hui LI

    2015-01-01

    CrAlVN coatings are of good intrinsic mechanical and tribological properties but lack of strength.Silicon can provide nitride coating high strength and excellent oxidation resistance.Logically,the combination of CrAlVN and Si should provide a good candidate for dry machining.The effect of silicon content on CrAlSiVN coating′s me-chanical,tribological properties and oxidation resistance was investigated.The coatings were deposited on cemented tungsten carbide and Si wafer (100)substrates in an in-line magnetron sputtering system.Grazing incidence X-ray diffractometer,scanning electron microscopy,atomic force microscopy,transmission electron microscopy,electron probe micro-analyzer,X-ray photoelectron spectroscopy and Auger electron spectroscopy were employed to charac-terize the microstructure and chemistry.Nanoindentation and ball-on-disc tribo-tester were used in characterization of the mechanical and tribological properties.Incorporating with silicon,the CrAlVN coating was strengthened (hard-ness:21.2 GPa up to 38.7 GPa);even after 2 h exposure to 700 ℃ in air,the hardness still maintains at 11.0 GPa.

  5. U-ALS: A Ubiquitous Learning Environment

    Science.gov (United States)

    Piovesan, Sandra Dutra; Passerino, Liliana Maria; Medina, Roseclea Duarte

    2012-01-01

    The diffusion of the use of the learning virtual environments presents a great potential for the development of an application which meet the necessities in the education area. In view of the importance of a more dynamic application and that can adapt itself continuously to the students' necessities, the "U-ALS" (Ubiquitous Adapted Learning…

  6. Bulk nanocrystalline Al prepared by cryomilling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bulk nanocrystalline Al was fabricated by mechanically milling at cryogenic temperature (cryomilling) and then by hot pressing in vacuum. By using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), the microstructure evolution of the material during cryomilling and consolidation was investigated. With increasing the milling time, the grain size decreased sharply and reduced to 42 nm when cryomilled for 12 h. The grains had grown up, and the columnar grain was formed under the hot pressing and extrusion compared with the cryomilled powders. The grain size of as-extruded specimen was approximately 300-500 nm. The reason of high thermal stability of this bulk was attributed primarily to the Zener pinning from the grain boundary of the AlN arising from cryomilling and the solute drag of the impurity. Tensile tests show that the strength of nanocrystalline Al is enhanced with decreasing grain size. The ultimate tensile strength and tensile elongation were 173 MPa and 17.5%, respectively. It appears that the measured high strength in the cryomilled Al is related to a grain-size effect, dispersion strengthening, and dislocation strengthening.

  7. Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al{sub 4}C{sub 3} and nano-Al{sub 2}O{sub 3} particles using wet milling in toluene

    Energy Technology Data Exchange (ETDEWEB)

    Razavi-Tousi, S.S., E-mail: ser105@mail.usask.ca [Islamic Azad University, Shahrood Branch, Shahrood (Iran, Islamic Republic of); Yazdani-Rad, R. [Materials and Energy Research Center, P.O. Box 31787/316, Karaj (Iran, Islamic Republic of); Manafi, S.A. [Islamic Azad University, Shahrood Branch, Shahrood (Iran, Islamic Republic of)

    2011-06-02

    Highlights: > Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al{sub 4}C{sub 3} and nano-Al{sub 2}O{sub 3} particles using wet milling in toluene. > Production of Al{sub 4}C{sub 3} particles from mechanochemical reaction of Al with PCA. > Effect of second phase particles on sintering. - Abstract: Al matrix nanocomposites were produced by wet milling of Al and nano-alumina powders in a toluene media. X-ray diffraction patterns, inductively coupled plasma, carbon measurement analysis and scanning electron microscopy show that impurities introduced by decomposition of toluene and abrasion of balls and vials are uniformly dispersed in the Al matrix as Al{sub 4}C{sub 3} and Fe-Al intermetallic particles. Though producing homogenous nanocomposites, these second phase particles seem to have a retarding effect on densification of nanocomposite powders.

  8. The origin of Al(OH)(3)-rich and Al(13)-aggregate flocs composition in PACl coagulation.

    Science.gov (United States)

    Lin, Jr-Lin; Huang, Chihpin; Chin, Ching-Ju M; Pan, Jill R

    2009-09-01

    The composition of hydrolyzed Al species is essential for the understanding of coagulation with Al-based coagulants. Surface characteristics of flocs formed by coagulation with two distinct polyaluminum chloride (PACl) coagulants were identified. One commercial coagulant (PACl-C) with voluminous monomeric Al and colloidal Al(OH)(3) and a custom-made PACl (PACl-Al(13)) containing high Al(13) content were applied to destabilize kaolin particles. The flocs formed by PACl-C and PACl-Al(13) at neutral and alkaline pH ranges, respectively, were observed by FE-SEM and HR-TEM. In addition, the Al composition of these flocs was characterized by XPS and HR-XRD, and the imaging of Al(OH)(3) precipitates and Al(13) aggregates were conducted by SEM as well as tapping mode AFM in liquid system. The observations of flocs indicate that the morphology of Al(OH)(3)-rich flocs are fluffy and porous around the edge of flocs, while the Al(13)-aggregate flocs have a glossy contour and irregular structure. Both Al(OH)(3)-rich and Al(13)-aggregate flocs do not possess well-formed crystalline structure except for the Al(13)-like crystal exists in the Al(13)-aggregate flocs. Among Al(OH)(3) precipitates, colloidal Al(OH)(3) is micro-scale in size, while amorphous Al(OH)(3) is nano-scale. During the formation of Al(13) aggregates, some coiled and clustered Al(13) aggregates with smoother surface were observed. The XPS study on floc surface showed that tetrahedral (Al(IV)) /octahedral (Al(VI)) Al ratio on the surfaces of PACl-C and PACl-Al(13) flocs is 1:1.6 and 1:9.9, respectively. Of the in situ formed Al(13), almost half of Al-hydroxide precipitates on the surface of Al(OH)(3)-rich flocs possess the Al(IV) center. It also found that the irregularly aggregated Al(13) with a similar Al(13) crystalline structure subsists on the surface of Al(13)-aggregate flocs.

  9. Microscopic phase field study of the antisite defect of Ni3 Al in binary Ni-Al alloys

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The temporal evolution feature of a microscopic phase field model is utilized to study the antisite defects of L1 2-Ni 3 Al;this is quite different from other physicist’ interests.There are mainly two points in brief.Firstly,antisite defects Ni Al and Al Ni ,which are caused by the deviation from the stoichiometric Ni 3 Al,coexist in the Ni 3 Al phase.The surplus Ni atom in the Ni-rich side is prone to substitute Al thus producing the antisite defect Ni Al that maintains the stability of the L1 2 structure.In other case,the surplus Al atom in the Al-rich side is accommodated by a Ni sublattice consequently giving rise to antisite defect Al Ni .The calculated equilibrium occupancy probability of Ni Al is much higher than that of Al Ni .This point is generally in line with other theoretical and experimental works.Additionally,both Ni Al and Al Ni have a strong negative correlation to time step during the disorder-order transformation.Since the initial value of Ni Al and Al Ni on each site of the matrix is right at the concentration that we set,we can observe the decrease process of Ni Al and Al Ni from the initial disordered high anti-structure state to their respective equilibrium state,i.e.to the result of the ordering process further coarsening.

  10. Wallada Bint al Mustakfi entre dos culturas

    Directory of Open Access Journals (Sweden)

    shreen Mahmoud Al Refai

    2013-10-01

    Full Text Available La princesa cordobesa Wallada Bint al Mustakfi bil-lah, hija del califa al Mustakfi Muhammad Ibn Abdel Rahman Ibn Obaidil-lah Ibn Al Nasir lidin Al-lah era una poetisa estimable, a quien los grandes poetas no podían superar. Era una mujer única, guapa y decente. Mantenía una relación sentimental con el  poeta y visir Ibn Zaydún. Dicha pasión, narrada por los poemas escritos por ambos amantes, se terminó por la separación debida a los celos, también de ambos;  al poeta le gustó la voz de una esclava de la princesa. Eso dio rabia a la última. Movido también por los celos, Ibn Zaydún dedicó una epístola satírica al visir Ibn Abdús, que estaba enamorado de Wallada. Tal hecho también irritó a la princesa. A pesar de tener amantes y admiradores, Wallada murió sin casarse al  día 2 de safar de 480 (o 484 de la Híjira pasando los ochenta años Me han llamado la atención el carácter tan culto, independiente y liberal de aquella mujer, su relación amorosa con Ibn Zaydún que no acabó felizmente y los muchos años que vivió sin casasre. Parece que la vida de la princesa hispano-musulmana llamó también la atención de muchos escritores árabes y españoles. Prueba de ello son varias obras literarias escritas en árabe y en español sobre Wallada e Ibn Zaydún. Por consiguiente, me resulta muy interesante realizar un estudio comparativo sobre este tema averiguando si, o no, la diferencia de culturas influiría en las opiniones  de los autores sobre la vida sentimental de aquella poetisa cordobesa.

  11. Una ventana al mundo de Kafka.

    Directory of Open Access Journals (Sweden)

    Guillermo Sánchez Medina

    2003-03-01

    Full Text Available

    COMENTARIO AL LIBRO " EL MUNDO PSICOLÓGICO DE KAFKA" POR EL ACADÉMICO ADOLFO DE FRANCISCO ZEA.

     

    Fui invitado en forma comedida, por el doctor Adolfo De Francisco, para comentar su obra: "El Mundo Psicológico de Kafka". Respondí que no era literato y menos crítico de Kafka. Sin embargo, acepté
    hacerlo siendo consciente de las limitaciones que me acompañan y para las que pido de todos ustedes su consideración. Tenía sí el deseo al reto de lo incógnito.
    Además sus argumentos fueron contundentes, pues se referían al compromiso con la Academia y, sin decírmelo, era también con él en nuestra historia compartida. Mis motivaciones y expectativas personales conscientes eran múltiples para sumergirme en sus ideas que mueven el espíritu desde la piel a lo trascendente, de lo interno a lo externo y viceversa, y en que cada palabra puede ser objeto de análisis profundo, pues esa es su esencia. Por ejemplo cuando el doctor De Francisco se refiere a la sublimación y a la estética, a la política, a la religiosidad, a la burguesía, al campesinado, a la nobleza, al absolutismo, al arte o a la historia, a la cosmovisión sociológica y literaria, al psicoanálisis para afrontar la realidad interna y externa, entonces el autor penetra en el mundo de la fantasía y del psiquismo, para entender el simbolismo implícito de Kafka.
    Las motivaciones personales inconscientes, pertenecen a las tendencias irracionales de hundirme en espacios complejos para luego intentar'ordenarlos; en medio está
    la contratransferencia que me une con el autor Adolfo De Francisco y otra la que se refiere a la temática kafkiana...

  12. ELECTROLYSIS OF SWINE MANURE EFFLUENTS USING THREE DIFFERENT ELECTRODES Fe-Fe, Al-Al AND Fe-Al

    Directory of Open Access Journals (Sweden)

    S. Rahman

    2014-01-01

    Full Text Available Swine effluent with high organic strength need to be treated to make it suitable for applying to crop/pasture fields, or discharging to any waterways. Electrocoagulation is a relatively simpler and cheaper technique over biological and chemical treatment methods currently used to treat high-strength industrial and municipal wastewater. The performance of an electrocoagulation system mainly depends on the pH, Electrical Conductivity (EC of the medium, Chemical Oxygen Demand (COD loading rates and catalytic activity of the electrodes used. In this research, a study was conducted to compare the pollutant removal efficiencies of three electrodes (Fe-Fe, Al-Al and Fe-Al with three electric current levels (500, 1000 and 2000 mA while treating swine manure effluents. The electrochemical cell consisted of two parallel rectangular plates (90×25×1.5 mm of Iron (Fe-Fe, Aluminum (Al-Al and Iron-Aluminum (Fe-Al, later on described as hybrid electrodes; immersed in a beaker with 550 mL swine effluents and powered by a Direct Current (DC supply. All studies were conducted in batches at room temperature. In general, removal efficiencies were increased with increasing current densities and electrolysis times for electrodes evaluated. Aluminum electrodes outperformed iron and hybrid (iron-aluminum electrodes in removing Total Phosphorus (TP at all current density levels tested. Overall, use of hybrid electrodes resulted in better COD removal. For the same treatment times (1200 s at higher current density (21 mA cm-2, hybrid electrodes removed about 100% COD, which are about 1.9 and 1.3 times higher than those of aluminum and iron electrodes, respectively. Iron electrodes showed the highest removal efficiency (85% for Total Organic Carbon (TOC at 21 mA cm-2 current density and 1200 s treatment time. Overall, lower Specific Electrical Energy Consumptions (SEECs per kg of Pollutants (TP, COD and TOC were estimated for the aluminum

  13. Medien als Lernform und die Trimediale Redaktion

    Directory of Open Access Journals (Sweden)

    Wolf Hilzensauer

    2015-01-01

    Full Text Available Der vorliegende Artikel beschreibt ein Konzept für eine handlungsorientierte Medienpädagogik im Bildungsbereich. Im Mittelpunkt steht dabei die SO!-Campusredaktion, die als Methode für expansives Lernen die Möglichkeit bietet, unabhängig von Thema oder Medium die Verantwortung für den Lernprozess in die Hände der Lernenden zu legen. Der Dokumentation von Reflexion über den Lernprozess wird dabei eine besondere Bedeutung zugesprochen. Gleichzeitig werden unterschiedliche mediale Gestaltungsmöglichkeiten (Audio/Radio, Video/Fernsehen und Zeitung – sowohl als Print- als auch als Onlinemedium vorgestellt, die durch das Konzept BYOD – bring your own device – auch einfach und niederschwellig im Bildungskontext umsetzbar sind. Dadurch ergeben sich innovative Möglichkeiten, einen Lernprozess sichtbar zu machen und gleichzeitig eine Grundlage für eine alternative Leistungsbeurteilung anzubieten. Die SO!-Campusredaktion wird derzeit an der Pädagogischen Hochschule Salzburg in Kooperation mit dem Communitysender FS1 und der Radiofabrik entwickelt und erprobt. Community Medien nehmen als MedienpartnerInnen eine bedeutende Stellung ein: Durch ihren offenen Zugang zu Know How und Equipment sowie durch die Möglichkeit, Medienproduktionen über die verfügbaren Distibutionskanäle (Radiofrequenz oder Sendeplatz einer breiten Bevölkerung zugänglich zu machen, gewinnt die Medienpädagogik einen wichtigen Mehrwert in ihrer schulischen und außerschulischen Arbeit. (Dieser Artikel knüpft an den Artikel "BYOD, Smartphonefilme und webbasierte Videoschnittprogramme" der Medienimpulse, Ausgabe 2/2014, an.

  14. Some TEM observations of Al2O3 scales formed on NiCrAl alloys

    Science.gov (United States)

    Smialek, J.; Gibala, R.

    1979-01-01

    The microstructural development of Al2O3 scales on NiCrAl alloys has been examined by transmission electron microscopy. Voids have been observed within grains in scales formed on a pure NiCrAl alloy. Both voids and oxide grains grew measurably with oxidation time at 1100 C. The size and amount of porosity decreased towards the oxide-metal growth interface. It was postulated that the voids resulted from an excess number of oxygen vacancies near the oxide-metal interface. Short-circuit diffusion paths were discussed in reference to current growth stress models for oxide scales. Transient oxidations of pure, Y-doped, and Zr-doped NiCrAl was also examined. Oriented alpha-(Al,Cr)2O3 and Ni(Al,Cr)2O4 scales often coexisted in layered structures on all three alloys. Close-packed oxygen planes and directions in the corundum and spinel layers were parallel. The close relationships between oxide layers provided a gradual transition from initial transient scales to steady state Al2O3 growth.

  15. PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

    Institute of Scientific and Technical Information of China (English)

    W.H. Tian; K. Ohishi; M. Nemoto

    2001-01-01

    Microstructural variations and correlated hardness changes in B2-ordered NiAl containing fine precipitation of Ni2AlTi have been investigated by means of transmission electron microscopy (TEM) and hardness tests. The amount of age hardening is not large as compared to the large microstructural variations during aging. TEM observations have revealed that the L21-type Ni2AlTi precipitates keep a lattice coherency with the NiAl matrix at the beginning of aging. By longer periods of aging Ni2AlTi precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. The temperature dependence of the yield strength of precipitate-containing B2-ordered NiAl was investigated by compression tests over the temperature range of 873-1273K. The fine precipitation of Ni2AlTi was found to enhance greatly the yield strength and the high-temperature strength is comparison with that of superalloy Mar-M200.``

  16. Wetting of polycrystalline SiC by molten Al and Al-Si alloys

    Science.gov (United States)

    Cong, Xiao-Shuang; Shen, Ping; Wang, Yi; Jiang, Qichuan

    2014-10-01

    The wetting of α-SiC by molten Al and Al-Si alloys was investigated using a dispensed sessile drop method in a high vacuum. In the Al-SiC system, representative wetting stages were identified. The liquid spreading was initially controlled by the deoxidation of the SiC surface and then by the formation of Al4C3 at the interface. The intrinsic contact angle for molten Al on the polycrystalline α-SiC surface was suggested to be lower than 90̊ provided that the oxide films covering the Al and SiC surfaces were removed, i.e., the system is partial wetting in nature. An increase in the Si concentration in liquid Al weakened the interfacial reaction but improved the final wettability. The role of the Si addition on the wetting was presumably attributed to its segregation at the interface and the formation of strong chemical bonds with the SiC surface.

  17. Formation and stability of Al-Nd and Al-Nd-Fe metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Battezzati, Livio (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy)); Baricco, Marcello (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy)); Antonione, Carlo (Dipartimento di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Universita di Torino, Via Pietro Giuria 9, 10125 Turin (Italy))

    1994-07-01

    Partially amorphous Al[sub 91]Nd[sub 9] and Al[sub 86]Nd[sub 9]Fe[sub 5] ribbons were prepared by melt spinning. Metastable crystalline phases were found in both alloys. Complete amorphization of Al[sub 86]Nd[sub 9]Fe[sub 5] was also achieved. Crystallization was monitored by differential scanning calorimetry (DSC). It occurs in two stages at 440 and 510 K for Al[sub 91]Nd[sub 9]. Al[sub 86]Nd[sub 9]Fe[sub 5] presented a eutectic crystallization at 550 K. Microscopy observations, combined with Johnson-Mehl-Avrami (JMA) analyses performed in isothermal DSC traces, showed that Al[sub 91]Nd[sub 9] transforms via growth on pre-existing crystals. Al[sub 86]Nd[sub 9]Fe[sub 5] transformed via heterogeneous nucleation on sites unevenly distributed through the ribbon. The fitting of isothermal peaks by means of the JMA equation was less satisfactory. The limits of this approach are discussed. ((orig.))

  18. Two medieval Maghreb chronicles: Al-Ḏajira Al-Saniyya y el Rawd al-Qirtas

    Directory of Open Access Journals (Sweden)

    Lidia Fernández Fonfría

    2010-03-01

    Full Text Available In the present communication I intend to expose my conclusions on asmall comparative study between two of the earliest Maghreb chronicles throwing information about the North African tribe of Banu Mar÷n arrival to the throne in the thirteenth century Maghreb. With these common features, allowing a more complete picture of anera, which is undoubtedly the least known of the merinid period, their beginning. The similarities and influences between them are such that there are different theories about a possiblecommon authorship. After concluding the study and subsequent analysis of these works, can be extracted that there are substantial differences on a structural and stylistic level that hinder the possible absolute identification of author of the Dhakh÷ra al-Saniyyawith the author of RawÅ al-QirÐās.

  19. Investigation Of Water Assisted Phase Transformation Process From AlPO4-5 to AlPO4-tridymite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Suochang; Zhao, Zhenchao; Hu, Mary Y.; Han, Xiuwen; Hu, Jian Z.; Bao, Xinhe

    2016-03-15

    Water assisted phase transformation process from crystalized AlPO4-5 to AlPO4-tridymite was studied by the combination of X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and in situ multinuclear MAS NMR. It is found that water first activates the residue amorphous aluminophosphate in crystalized AlPO4-5 sample through hydrolysis and condensation reactions. Then the activated aluminophosphate species reassemble into AlPO4-tridymite crystalline. Meanwhile, AlPO4-5 transforms into orthorhombic phase during heating process. With further crystallization of AlPO4-tridymite, the amorphous phase is gradually consumed, and mass transportation between AlPO4-5 and AlPO4-tridymite is established through gradually amorphization of AlPO4-5. Finally, most of the AlPO4-5 transforms into the thermodynamically stable dense phase AlPO4-tridymite.

  20. An epidemiological study of cutaneous leishmaniasis in Al-jabal Al-gharbi, Libya.

    Science.gov (United States)

    Abdellatif, Manal Z M; El-Mabrouk, Khamis; Ewis, Ashraf A

    2013-02-01

    Cutaneous leishmaniasis (CL) is an endemic parasitic infection in the Mediterranean region, including Libya and its Al-jabal Al-gharbi province. We aimed at studying the occupational relevance as well as other epidemiological aspects of CL. We investigated 140 CL cases who attended at Gharyan outpatient polyclinic during a period of 6 months in 2009. CL infection was clinically diagnosed and confirmed by demonstration of Leishmania parasites on smears from lesions. Our findings showed that males were more affected than females (P=0.04), and people above 10-years were more affected than younger ones (P=0.0001). A significant percent of CL cases belonged to Al-Kawasem subprovince (P=0.0001). Farm-related activities were the most frequent occupations among CL cases (P=0.04). In addition to farm workers, housewives and students are at risk groups since they are engaged at farm activities. Moreover, those who have occupations that require staying outdoors for a part of night, e.g., policemen, are also at risk. Compared to children, adult CL patients had multiple lesions (P=0.001) that were more prevalent in their upper and lower extremities than the face (P=0.0001). We conclude that CL is a major health problem in Al-jabal Al-gharbi province of Libya. The presence of rodents and sandflies makes it a suitable environment for Leishmania to spread in an endemic epidemiological pattern. Being engaged in farming activities or outdoor occupations increases the risk of infection. Various clinical patterns of CL suggest the presence of more than 1 species of Leishmania at Al-jabal Al-gharbi province. We propose that the 2 species responsible for CL in this area are L. major and L. tropica. Further investigations to identify the leishmanial species responsible for CL at Al-jabal Al-gharbi together with adoption of preventive and control programs are needed.

  1. Pemikiran Politik al-Shawkânî dalam Fath al-Qadîr

    Directory of Open Access Journals (Sweden)

    Yusuf Hanafi

    2015-09-01

    Full Text Available Muhammad b. ‘Alî Muhammad b. ‘Abd Allâh al-Shawkânî al-San‘ânî. He was born in the Hijrah in Shawkân village, Yemen on Monday 28 Dhû al-Qa‘dah 1172 H and died on Tuesday, 27 Jumâd al-Akhîr 1250 H at the age about 78 years. Al-Shawkânî grew up in the San‘a city, it is the capital of the republic of Yemen now. He study first time about religion from his father, then from renowed scholars in San‘a and its surrounding, he was known as a scolar who mastered the various branches of religious sciences. Such as tafsîr, h}adîth, fiqh, us}ûl al-fiqh, history, science of kalâm, philosophy, balâghah, mant}iq etc. the main issue in this article is how political thought in the book of tafsir Fath al-Qadîr is the work of Shawkânî. At the end of article, the authors found that the intended political thinking in the study of Fath al-Qadîr is about constitutional ideas. These ideas about the constitution is limited to the concept of leadership and deliberation, the concept of the right of citizen to obtain justice, and the concept pf the right of citizens to live association and assembly

  2. Al-C/Al-N/Al涂层膜基结合强度工艺试验研究%Study on Bond Strength of Al-C/Al-N/Al Coating Film

    Institute of Scientific and Technical Information of China (English)

    陈梅; 王刚

    2012-01-01

    通过对Al-C/Al-N/Al太阳能选择性吸收涂层沉积工艺的研究,分析了该涂层膜基结合强度较差的原因,进行了不同沉积工艺条件下的涂层膜基结合强度、吸收率和热损试验,对试验结果进行了仔细的分析,优化确认在Al-C/Al-N/Al太阳能选择性吸收涂层沉积工艺基础上实施第N层充N2气体工艺,可以较好的提高涂层的膜基结合强度,同时保证涂层的吸收率和集热管的热损不发生明显的下降.%Through the study of sedimentary technology on the Al-C/Al-N/Al solar energy selective absorption coating,the authors analyzed the reason why the film-basis bond strength is weak,and took experiments on film-basis bond strength of coating,absorptivity and thermal loss under different sedimentary conditions.After analyzing the trial results,it is confirmed that practicing the N layer and N2 air technology based on sedimentary technology on the Al-C/Al-N/Al solar energy selective absorption coating can improve the film-basis bond strength of coating,and ensure the nonoccurrence of apparent decline in coating absorptivity and thermal loss of heat collecting cubes.

  3. Spectroscopic analysis of the open 3d subshell transition metal aluminides: AlV, AlCr, and AlCo

    Science.gov (United States)

    Behm, Jane M.; Brugh, Dale J.; Morse, Michael D.

    1994-10-01

    Three open 3d subshell transition metal aluminides, AlV, AlCr, and AlCo, have been investigated by resonant two-photon ionization spectroscopy to elucidate the chemical bonding in these diatomic molecules. The open nature of the 3d subshell results in a vast number of excited electronic states in these species, allowing bond strengths to be measured by the observation of abrupt predissociation thresholds in a congested optical spectrum, giving D00(AlV)=1.489±0.010 eV, D00(AlCr)=2.272±0.009 eV, and D00(AlCo)=1.844±0.002 eV. At lower excitation energies the presence of discrete transitions has permitted determinations of the ground state symmetries and bond lengths of AlV and AlCo through rotationally resolved studies, giving r0` (AlV, Ω`=0)=2.620±0.004 Å and r0` (AlCo, Ω`=3)=2.3833±0.0005 Å. Ionization energies were also measured for all three species, yielding IE(AlV)=6.01±0.10 eV, IE(AlCr)=5.96±0.04 eV, and IE(AlCo)=6.99±0.17 eV. A discussion of these results is presented in the context of previous work on AlCu, AlNi, AlCa, and AlZn.

  4. In-situ synthesized (Al3Zr+Al2O3)p/A356 composites by direct melt reaction in Al-Zr-O system

    Institute of Scientific and Technical Information of China (English)

    赵玉涛; 李忠华; 程晓农; 戴起勋; 蔡兰

    2003-01-01

    A novel in-situ reaction system Al-Zr-O was developed. In situ Al3Zr and Al2O3 particulate reinforced A356 alloy matrix composites have been fabricated by direct melt reaction method. The results show that the maximum sizes of Al3Zr and Al2O3 particulates synthesized in the system ZrOCl2-A356 are 1 μm and 3 μm respectively, and they are well distributed in the matrix. The investigation shows that the Al3Zr crystal is in the shape of polyhedron and rectangle. There is a faceted growth phenomenon on Al3Zr crystal surface. It is firstly found that the Al3Zr crystal grows in the mechanism of twinning. The twinning plane is (1 1 4), and the twinning direction is [2 2 1]. The crystal morphology of in-situ α-Al2O3 particulate is rectangle or sphere. Furthermore, (Al3Zr+Al2O3)p/A356 composites have not only higher tensile strength at room temperature (376.2 MPa) but also higher yield strength (319.4 MPa) and higher tensile strength at elevated temperature (200 ℃) than those of the A356 alloy. The dry sliding wear test shows that the wear resistance of the (Al3Zr+Al2O3)p/A356 composites is greatly enhanced with increasing particulate volume fraction.

  5. APOYO PÚBLICO A LA ENERGÍA EÓLICA EN ESPAÑA

    Directory of Open Access Journals (Sweden)

    Masao Javier López Sako

    2009-01-01

    Full Text Available El presente trabajo pretende describir y valorar brevemente el régimen jurídico-económico de la energía eólica en España. Nos referimos en concreto al sistema de apoyo público a la producción de electricidad a partir de las energías renovables mediante el sistema denominado "de primas". El fijarnos en la energía eólica en particular se justifica por la sencilla razón de que España ocupa el tercer puesto a nivel mundial en potencia eólica instalada, después de Alemania y EE. UU, hecho que va unido a la circunstancia de la importancia a todos los niveles que ha cobrado este sector en España. Por otra parte, conviene recordar que el uso de energía (su producción y consumo es el principal factor de emisiones de gases de efecto invernadero y las energías renovables suponen una pieza clave en la lucha contra el cambio climático. Y también que España se encuentra entre los países más alejados del cumplimiento del Protocolo de Kyoto. Desde esta perspectiva, el protagonismo de la energía eólica es también patente: en nuestro país, dentro de las energías renovables, la energía eólica en particular es la que más está aportando al mix de generación eléctrica, convirtiéndose en la contribución más segura a dicha lucha ambiental de carácter global. En este sentido, la proporción de energía eléctrica aportada por la eólica se encuentra -con más del 11% en 2008- en la segunda posición mundial; aquí España solo es superada por Dinamarca. Es importante, por tanto, mantener una buena política de fomento de esta tecnología renovable.

  6. 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.

  7. Hardness Measurement of (TiB2-TiAl)/TiAl Symmetrically Function Gradient Materials

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    (TiB2-TiAl)/TiAl symmetrically function gradient materials (FGM) were prepared by spark plasma sintering (SPS). Owing to the difference of the thermal expansion coefficients between TiB2 and TiAl, a compressive surface stress was introduced to the FGM by the thermal expansion mismatch. The hardness values of the uniform materials and the FGM were tested, respectively. For the FGM with a compressive surface stress, hardness is obviously superior to that of the uniform material.When the FGM was subjected to heat treatment,the hardness decreased due to a partial relaxation of the compressive surface stress.

  8. Structure of 26Al studied by one - nucleon transfer reaction 27Al(d,t

    Directory of Open Access Journals (Sweden)

    Srivastava Vishal

    2015-01-01

    Full Text Available The excited states of 26Al have been produced and studied using 27Al(d,t reaction with 25 MeV deuteron as projectile. Optical model potential parameters were extracted from the measured elastic scattering angular distribution. Zero range distorted wave Born approximation analysis for the ground and 0.223 MeV states of 26Al have been done. The spectroscopic factors calculated for these states are found to be in good agreement with the previously reported values.

  9. Adherent Al2O3 scales formed on undoped NiCrAl alloys

    Science.gov (United States)

    Smialek, James L.

    1987-01-01

    Changes in the spalling behavior of Al2O3 scales formed on an undoped NiCrAl alloy are described. Two samples of Ni-15Cr-13Al (wt pct), one a control and the other sanded, were subjected to 25 oxidation cycles. It is observed that adherent scales formed on the sanded sample; however, the control sample had speckled, spalled scales. The data reveal that the adherent scales are caused by repeated removal of surface layers after each oxidation cycle. It is determined that interfacial segregation of sulfur influences spallation and sulfur removal increases bonding. The effect of moisture on scale adhesions is investigated.

  10. Punishment on Stage: Application of Islamic Criminal Law by Harakat al-Shabaab al-Mujahideen

    OpenAIRE

    Skjelderup, Michael

    2011-01-01

    Harakat al-Shabaab al-Mujahideen, usually referred to as al-Shabaab (“the youth”), is mostly known as a Somali terrorist group. But since the end of 2008 it has functioned as a state power in large parts of Southern and Central Somalia. In this study I sketch out the structure and function of the legal system of the group. Over the last three years they have developed an administrative structure and a legal system which is unprecedented in the Somali conflict, which has lasted for more than 2...

  11. InAlGaAs/AlGaAs quantum wells: line widths, transition energies and segregation

    DEFF Research Database (Denmark)

    Jensen, Jacob Riis; Hvam, Jørn Märcher; Langbein, Wolfgang

    2000-01-01

    We investigate the optical properties of InAlCaAs/AlGaAs quantum wells pseudomorphically grown on GaAs using molecular beam epitaxy (MBE). The transition energies, measured with photoluminescence (PL), are modelled solving the Schrodinger equation, and taking into account segregation in the group...... III sublattice. From a fit to the transition energies, an empirical band gap relation for InAlGaAs is found, in the composition range relevant for growth on GaAs. The PL lines at low temperature (T = 10 K) are broadened due to random alloy fluctuations and an interface roughness of 1.1 monolayers...

  12. Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

    Science.gov (United States)

    Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

    2017-03-01

    The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating steel with Al-Si coating steel without any coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

  13. Mechanical properties and electronic structures of Fe-Al intermetallic

    Science.gov (United States)

    Liu, YaHui; Chong, XiaoYu; Jiang, YeHua; Zhou, Rong; Feng, Jing

    2017-02-01

    Using the first-principles calculations, the elastic properties, anisotropy properties, electronic structures, Debye temperature and stability of Fe-Al (Fe3Al, FeAl, FeAl2, Fe2Al5 and FeAl3) binary compounds were calculated. The formation enthalpy and cohesive energy of these Fe-Al compounds are negative, and show they are thermodynamically stable structures. Fe2Al5 has the lowest formation enthalpy, which shows the Fe2Al5 is the most stable of Fe-Al binary compounds. These Fe-Al compounds display disparate anisotropy due to the calculated different shape of the 3D curved surface of the Young's modulus and anisotropic index. Fe3Al has the biggest bulk modulus with the value 233.2 GPa. FeAl has the biggest Yong's modulus and shear modulus with the value 296.2 GPa and 119.8 GPa, respectively. The partial density of states, total density of states and electron density distribution maps of the binary Fe-Al binary compounds are analyzed. The bonding characteristics of these Fe-Al binary compounds are mainly combination by covalent bond and metallic bonds. Meanwhile, also exist anti-bond effect. Moreover, the Debye temperatures and sound velocity of these Fe-Al compounds are explored.

  14. Microstructure of Ni-Al powder and Ni-Al composite coatings prepared by twin-wire arc spraying

    Institute of Scientific and Technical Information of China (English)

    Ji-xiao Wang; Gui-xian Wang; Jing-shun Liu; Lun-yong Zhang; Wei Wang; Ze Li; Qi-xiang Wang; Jian-fei Sun

    2016-01-01

    Ni–Al powder and Ni–Al composite coatings were fabricated by twin-wire arc spraying (TWAS). The microstructures of Ni-5wt%Al powder and Ni-20wt%Al powder were characterized by scanning electronic microscopy (SEM) and energy dispersive spec-troscopy (EDS). The results showed that the obtained particle size ranged from 5 to 50μm. The morphology of the Ni–Al powder showed that molten particles were composed of Ni solid solution, NiAl, Ni3Al, Al2O3, and NiO. The Ni–Al phase and a small amount of Al2O3 parti-cles changed the composition of the coating. The microstructures of the twin-wire-arc-sprayed Ni–Al composite coatings were characterized by SEM, EDS, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results showed that the main phase of the Ni-5wt%Al coating consisted of Ni solid solution and NiAl in addition to a small amount of Al2O3. The main phase of the Ni-20wt%Al coating mainly consisted of Ni solid solution, NiAl, and Ni3Al in addition to a small amount of Al and Al2O3, and NiAl and Ni3Al intermet-allic compounds effectively further improved the final wear property of the coatings. TEM analysis indicated that fine spherical NiAl3 pre-cipitates and a Ni–Al–O amorphous phase formed in the matrix of the Ni solid solution in the original state.

  15. Gate length scaling effect on high-electron mobility transistors devices using AlGaN/GaN and AlInN/AlN/GaN heterostructures.

    Science.gov (United States)

    Liao, S Y; Lu, C C; Chang, T; Huang, C F; Cheng, C H; Chang, L B

    2014-08-01

    Compared to AlGaN/GaN HEMT with 0.15 μm T-gate length, the AlInN/AlN/GaN one exhibits much higher current density and transconductance of 1558 mA/mm at Vd = 2 V and 330 mS/mm, respectively. The high extrinsic ft and fmax of 82 GHz and 70 GHz are extracted from AlInN/AlN/GaN HEMT. Besides, we find that the transconductance roll-off is significant in AlGaN/GaN, but largely improved in AlInN/AlN/GaN HEMT, suggesting that the high carrier density and lattice-matched epitaxial heterostructure is important to reach both large RF output power and high operation frequency, especially for an aggressively gate length scaling.

  16. The Formation of γ—AlON Spinel in the Reaction of Al2O3—AlN—MgO System

    Institute of Scientific and Technical Information of China (English)

    LIYawei; YUANRunzhang; 等

    1997-01-01

    The stabilization of γ-aluminium oxyni-tride spinel(γ-AlON) has been investigated by addition of MgO,MgAl2O4,etc.,in reaction process.The results indicated that there are wider solid solution areas near ,Al2O3-rich side in AlN-Al2O3-MgO ternary systems,The content of stabilized AlON phase in samples is related to heating temperatures,additives,etc.The lattice parameters of their AlON phases could be well describedby the equation: a0=0.7900+0.0375[MgO]+0.015[AlN](nm)

  17. Oxidation Behaviour of Sputtered Ni-3Cr-20Al Alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxidation behavior of sputtered Ni-3Cr-20Al coating at 900°C in air was investigated. A dense Al2O3 layer was formed on the sputtered Ni-3Cr-20Al coating after 200 h oxidation.However, owing to the segregation of Ni3Al during oxidation Focess at high temperature, the spinel NiAl2O4 was also formed in the Al2O3 layer. It was found that the formation of NiAl2O4had no detrimental effect on the oxidation resistance of the sputtered Ni-3Cr-20Al coating due to the excellent adhesion shown by the Al2O3 and NiAl2O4 complex oxide scale.

  18. Environmental embrittlement of intermetallic compounds in Fe-Al alloys

    Institute of Scientific and Technical Information of China (English)

    张建民; 张瑞林; S.H.YU; 余瑞璜

    1996-01-01

    First,it is proposed that hydrogen atoms occupy the interstitial sites in Fe3Al and FeAl.Then the environmental embrittlement of intermetallic compounds in Fe-Al alloys is studied in the light of calculated valence electron structures and bond energy of Fe3Al and FeAl containing hydrogen atoms.From the analyses it is found that the states of metal atoms will change,in which more lattice electrons will become covalent electrons to bond with hydrogen atoms when the atomic hydrogen diffuses into the intermetallic compounds in Fe-Al alloys,which will result in the decrease of local metallicity in Fe3Al and FeAl.Meanwhile,it is found that the crystal will easily cleave since solute hydrogen bonds with metal atoms and severely anisotropic bonds form.As a conclusion,these factors result in the environmental embrittlement of Fe3Al and FeAl.

  19. Electrochemical corrosion behavior of arc sprayed Zn-Al coatings

    Institute of Scientific and Technical Information of China (English)

    LIU Yan; ZHU Zi-xin; CHEN Yong-xiong; XU Bin-shi; MA Shi-ning; LI Zhuo-xin

    2004-01-01

    Cored wires and high velocity arc spraying (HVAS) technique were applied to produce high Al content Zn-Al alloy coatings on low carbon steel substrates. The electrochemical corrosion behaviors of Zn, Al and Zn-Al coatings were studied with potentiodynamic measurement in 5 % NaCl solution. Compared with pure Zn, pure Al and Zn-15Al coatings, Zn-26Al coatings show a higher corrosion resistance in salt solution. The potentiodynamic polarization tests show that the corrosion resistance of Zn-Al coatings increases as Al content is raised. Pure Al coating exhibits different electrochemical behaviors with other coatings. The corrosion initiated at the micro-pores of the coating and the underlying corrosion mechanism is very similar to that of the pitting corrosion.

  20. Properties of porous FeAlO/FeAl ceramic matrix composite influenced by mechanical activation of FeAl powder

    Indian Academy of Sciences (India)

    V Usoltsev; S Tikhov; A Salanov; V Sadykov; G Golubkova; O Lomovskii

    2013-12-01

    Porous ceramic matrix composites FeAlO/FeAl with incorporated metal inclusions (cermets) were synthesized by pressureless method, which includes hydrothermal treatment of mechanically alloyed FeAl powder followed by calcination. Their main structural, textural and mechanical features are described. Variation of FeAl powder alloying time results in non-monotonous changes of the porosity and mechanical strength. Details of the cermet microstructure and its relation to the mechanical properties are discussed.

  1. Observable Proxies For 26 Al Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Christopher L [Los Alamos National Laboratory; Young, Patrick A [Los Alamos National Laboratory; Ellinger, Carola I [ASU; Arnett, William D [UNIV ARIZONA

    2008-01-01

    We consider the cospatial production of elements in supernova explosions to find observationally detectable proxies for enhancement of {sup 26}Al in supernova ejecta and stellar systems. Using four progenitors we explore a range of 1D explosions at different energies and an asymmetric 3D explosion. We find that the most reliable indicator of the presence of {sup 26}Al in unmixed ejecta is a very low S/Si ratio ({approx} 0.05). Production of N in O/S/Si-rich regions is also indicative. The biologically important element P is produced at its highest abundance in the same regions. Proxies should be detectable in supernova ejecta with high spatial resolution multi wavelength observations, but the small absolute abundance of material injected into a proto-planetary disk makes detection unlikely in existing or forming stellar/planetary systems.

  2. Forging of FeAl intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Flores, O.; Juarez, J.; Campillo, B.; Martinez, L. [UNAM, Cuernavaca (Mexico). Lab. de Cuernavaca; Schneibel, J.H. [Oak Ridge National Lab., TN (United States)

    1994-09-01

    Much activity has been concentrated on the development of intermetallic compounds with the aim of improving tensile ductility, fracture toughness and high notch sensitivity in order to develop an attractive combination of properties for high and low temperature applications. This paper reports experience in processing and forging of FeAl intermetallic of B2 type. During the experiments two different temperatures were employed, and the specimens were forged after annealing in air, 10{sup {minus}2} torr vacuum and argon. From the results it was learned that annealing FeAl in argon atmosphere prior to forging resulted in better deformation behavior than for the other two environments. For the higher forging temperature used in the experiments (700C), the as-cast microstructure becomes partially recrystallized.

  3. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Santella, M.L.; Alexander, D.J. [Oak Ridge National Laboratory, TN (United States)] [and others

    1995-05-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for (1)high-strength castable composition for turbochargers, furnace furniture, and hot-die applications; (2) castability (fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) hot fabricability of cast ingots. All of the issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes work completed to address some of these issues during the fourth quarter of FY 1994.

  4. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Viswanathan, S.; Santella, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  5. Communication Support for People with ALS

    Directory of Open Access Journals (Sweden)

    David Beukelman

    2011-01-01

    Full Text Available Almost all people with amyotrophic lateral sclerosis (ALS experience a motor speech disorder, such as dysarthria, as the disease progresses. At some point, 80 to 95% of people with ALS are unable to meet their daily communication needs using natural speech. Unfortunately, once intelligibility begins to decrease, speech performance often deteriorates so rapidly that there is little time to implement an appropriate augmentative and alternative communication (AAC intervention; therefore, appropriate timing of referral for AAC assessment and intervention continues to be a most important clinical decision-making issue. AAC acceptance and use have increased considerably during the past decade. Many people use AAC until within a few weeks of their deaths.

  6. Hydrogen diffusion in Al-Li alloys

    Science.gov (United States)

    Anyalebechi, P. N.

    1990-08-01

    The diffusion coefficients of hydrogen in binary Al-Li alloys containing 1,2, and 3 wt pct Li have been determined from desorption curves of samples saturated with hydrogen at 473 to 873 K. Within this temperature range, the diffusivity of hydrogen in the binary Al-Li alloys investigated has an Arrhenius-type temperature dependence and follows the equation of the general form D = DT) where D 0exp(-Q/R is the diffusion coefficient (m2/s), D 0 is the preexponential or frequency factor (m2/s), R is the gas constant (J/K mol), Q is the activation energy (J/mol), and T is absolute temperature (K). The rate of diffusion of hydrogen in aluminum decreases with increase in lithium additions. This is provisionally attributed to the stronger local binding energy between hydrogen and lithium atoms in the aluminum metal lattice.

  7. Spherical foam growth in Al alloy melt

    Institute of Scientific and Technical Information of China (English)

    SHANG; Jintang; HE; Deping

    2005-01-01

    Due to the demand of high-tech Al alloy foam with spherical pores, high strength and high energy-absorption capacity has become one of the research foci. The aim of this study is to ascertain the growth regularity of spherical foam in Al alloy melt. Three-dimensional packing model such as face-centered cubic is established to study the spherical foam growth. Theoretical results are compared with experimental ones, and the face-centered cubic model corresponds well with the experiment. It is reasonable to assume that the pores have the same radius, the total pore number keeps unchanged and spherical foam grows with face-centered cubic packing mode. This study presents a useful help to control the average pore radius and film thickness.

  8. [Communication with ALS patients: neurosurgical approach].

    Science.gov (United States)

    Yoshimine, Toshiki; Yanagisawa, Takufumi; Sawada, Jin-Ichi; Hazama, Takanori; Mochizuki, Hideki; Hirata, Masayuki

    2013-01-01

    By progression of the disease, motor neurons degenerate in patients with amyotrophic lateral sclerosis (ALS) eventually lose nearly all voluntary muscles in the body. They are awake and aware but cannot move or communicate (locked-in state). Since the function of the brain is preserved, one possible measure to support their communication is to interpret their motor intention by decoding (deciphering) brain signals and present it with external devices. This technology called "brain-machine interface (BMI)" is now close to clinical use in Japan and USA.In our system, we record electrocorticogram (ECoG) obtained with subudural electrodes during their motor imagery, decode it and determine the movement they intended. So far, one patient of ALS with severe paralysis, implanted with this electrodes, successfully operated the PC communication tool only by thinking.

  9. Status of the AlCap experiment

    CERN Document Server

    Litchfield, R Phillip

    2015-01-01

    The AlCap experiment is a joint project between the COMET and Mu2e collaborations. Both experiments intend to look for the lepton-flavour violating conversion $\\mu + A \\rightarrow e + A$, using tertiary muons from high-power pulsed proton beams. In these experiments the products of ordinary muon capture in the muon stopping target are an important concern, both in terms of hit rates in tracking detectors and radiation damage to equipment. The goal of the AlCap experiment is to provide precision measurements of the products of nuclear capture on Aluminium, which is the favoured target material for both COMET and Mu2e. The results will be used for optimising the design of both conversion experiments, and as input to their simulations. Data was taken in December 2013 and is currently being analysed.

  10. The Byzantines in Medieval Arabic Poetry: Abu Firas’ "Al-Rumiyyat" and the Poetic Responses of al-Qaffal and Ibn Hazm to Nicephore Phocas’ "Al-Qasida al-Arminiyya al-Malʿuna" (The Armenian Cursed Ode

    Directory of Open Access Journals (Sweden)

    Nizar F. HERMES

    2009-10-01

    Full Text Available Up until the Crusades, it was al-Rūm who were universally seen by Arab writers and Arab poets in particular as the Other par excellence. Nowhere is this more conspicuous than in the sub-genre of Al-Rūmiyyat (poems about the Byzantines, namely as found in the Rūmiyyat of Abu Firas al-Hamdani(d.968, and in the poetic responses of al-Qaffal(d. 946 and Ibn Hazm(d. 1064 to what was described by several medieval Muslim chronicles as Al-Qasida al-Arminiyya al-Malʿuna (The Armenian Cursed Ode. By exploring the forgotten views of the Byzantines in medieval Arabic poetry, this article purports to demonstrate that contrary to the impression left after reading Edward Said’s groundbreaking Orientalism: Western Conceptions of the Orient (1978 and other postcolonial studies, Orientals have not existed solely to be ‘orientalized’. Perhaps even before this came to be so, they too had ‘occidentalized’ their Euro-Christian Other(s in a way that mirrored in reverse the subject/object relationship described as Orientalism.

  11. KISAH DZULQARNAIN DALAM AL-QUR’AN SURAT AL-KAHFI: 83-101 (Pendekatan Hermeneutik

    Directory of Open Access Journals (Sweden)

    Rukimin Rukimin

    2016-06-01

    ingkar hendaknya diajak bertobat dan kembali kepada keimanan dengan diperingatkan akan kekufurannya bahwa Allah akan mengazab orang-orang yang ingkar. Kata Kunci: Dzhulqarnai; al-Qu’an; hermeneutika

  12. Fabrication and properties of functionally graded NiAl/Al2O3 composites

    Science.gov (United States)

    Miller, D. P.; Lannutti, J. J.; Noebe, R. D.

    1993-01-01

    A modified sedimentation process was used in the production of a functionally gradient material (FGM), NiAl/Al2O3. A simple finite element model was used to guide our design and fabrication efforts by estimating residual stress states as a function of composite structure. This approach could lead to tailored designs that enhance or avoid specific residual stress states. Thermal cycling tests were factored into the model to predict time dependent or steady-state internal temperature and stress profiles. Four-point bend tests were conducted to establish the mechanical load-displacement behavior of a single interlayer FGM at room temperature, 800 and 1000 K. Room temperature bend strength of the FGM was 3-4 times that of the base NiAl. At elevated temperatures, composite fracture occurred in a gradual, noncatastrophic mode involving NiAl retardation of a succession of cracks originating in the alumina face.

  13. Fabrication of high-quality submicron Nb/Al-AlOx/Nb tunnel junctions

    Institute of Scientific and Technical Information of China (English)

    Yu Hai-Feng; Cao Wen-Hui; Zhu Xiao-Bo; Yang Hai-Fang; Yu Hong-Wei; Ren Yu-Feng; Gu Chang-Zhi; Chen Geng-Hua; Zhao Shi-Ping

    2008-01-01

    Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and supercon-ducting qubit applications of the Josepheon devices. In this work, we describe a convenient and reliable process using electron beam lithography for the fabrication of high-quality, submicron-sized Nb/Al-AlOx/Nb Josephson junctions.The technique follows the well-known selective Nb etching process and produces high-quality junctions with Vm=100 mV at 2.3 K for the typical critical current density of 2.2 kA/cm2, which can be adjusted by controlling the oxygen pressure and oxidation time during the formation of the tunnelling barrier. We present the results of the temperature depen-dence of the sub-gap current and in-plane magnetic-field dependence of the critical current, and compare them with the theoretical predictions.

  14. Effect of partial melting on superplasticity ofAlNp/6061Al composite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AlN particulate reinforced 6061 aluminum alloy composite was fabricated by powder metallurgy method and hot-rolled after extrusion. Tensile strength and elongation at elevated temperature were measured by tensile test at initial strain rates between 10-2 s-1 and 100 s-1. The AlNp/6061Al composite exhibits an m-value of 0.42 and a maximum elongation of 450% at 863?K. Differential scanning calorimeter was used to ascertain the possibility of any partial melting in the vicinity of optimum superplastic temperature. Partial melting resulting from solute segregation at interfaces has much influence on superplasticity of the composite. It is postulated that AlNp/matrix interface sliding occurs along with grain boundary in superplastic deformation.

  15. Adherent Al2O3 scales produced on undoped NiCrAl alloys

    Science.gov (United States)

    Smialek, James L.

    1986-01-01

    Repeated oxidation and polishing of high purity Ni-15Cr-13Al has dramatically changed its cyclic oxidation behavior from nonadherent to adherent. No apparent change in scale phase, morphology or interface structure occurred during this transition, dismissing any mechanism based on pegging, vacancy sink, or growth stress. The principle change that did occur was a reduction in the sulfur content from 10 ppmw to 3 ppmw after 25 cycles at 1120 C. These observations are used to support the model of Al2O3 scale adherence put forth by Smeggil et al. which claims that Al2O3 scale spallation occurs due to sulfur segregation and bond deterioration at the oxide-metal interface.

  16. Fabrication Of Al 2024/SiC Nanocomposite with Al and Cu Pure Coatings

    Directory of Open Access Journals (Sweden)

    P. Melali

    2015-06-01

    Full Text Available Composites find an important place as new advanced materials in last decades; those especially produced with nanoparticles reinforcements, attracts researchers and a number of researches were executed on this topic. In this study, Al-base 2024 alloy composites reinforced with SiC nanoparticles were fabricated and the effects of two different coating materials were investigated. Coatings were pure Al and Cu powder with constant grain particle size. The results show that the Al coating has impacts on grain size and the interface layer between reinforcement and matrix. The mechanism of formation of interface layer between SiC nanoparticles and the Al-base 2024 matrix with reinforced with Cu coated SiC particles is quite different.

  17. Die Welt als Puppenhaus. Die verzauberten Filme des Wes Anderson als Retrospektive im Kino Xenix

    OpenAIRE

    Binotto, Johannes

    2012-01-01

    Nur gerade sieben Filme hat der Regisseur und Autor Wes Anderson bisher gemacht, damit aber ein einzigartiges Œuvre geschaffen. Das Xenix zeigt diese melancholischen und verspielten Kunstwerke, zusammen mit Filmen, die als Inspiration dienten.

  18. 77 FR 73732 - In the Matter of the Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa...

    Science.gov (United States)

    2012-12-11

    ... Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al-Jihad, aka The Monotheism and Jihad Group, aka The al-Zarqawi Network, aka al-Tawhid, aka Tanzim Qa`idat al-Jihad fi Bilad al-Rafidayn, aka The Organization of al-Jihad's Base of Operations in Iraq, aka al-Qaida of Jihad in Iraq, aka al-Qaida in Iraq,...

  19. 77 FR 4083 - Amendment of the Designation of al-Qa'ida in Iraq, et al. as a Specially Designated Global...

    Science.gov (United States)

    2012-01-26

    ..., aka Jam'at al Tawhid wa'al-Jihad, aka The Monotheism and Jihad Group, aka The al-Zarqawi Network, aka al-Tawhid, aka Tanzim Qa`idat al-Jihad fi Bilad al-Rafidayn, aka The Organization of al- Jihad's Base of Operations in Iraq, aka al-Qaida of Jihad in Iraq, aka al-Qaida in Iraq, aka al-Qaida...

  20. Entspannung als Wirkfaktor in der manuellen Stimmbehandlung

    OpenAIRE

    Lehnert, B.; Schlasze, H; Siebertz, S; Neuschaefer-Rube, C

    2010-01-01

    Hintergrund: Verschiedene Studien sprechen für eine Wirksamkeit der Manuellen Therapien (z. B. Osteopathie) nicht nur bei der sog. "Zervikogenen Dysphonie", sondern auch bei hyperfunktionellen Dysphonien. Unsere klinische Erfahrung zeigt, dass Patienten eine manuelle Behandlung der HWS als sehr entspannend empfinden. Uns sind keine Arbeiten bekannt, die den Anteil dieser allgemeinen Entspannung am Behandlungserfolg der Manuellen Therapien untersuchen. Wir stellen eine erste Studie zum Vergle...

  1. Psychosocial adjustment to ALS: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Tamara eMatuz

    2015-09-01

    Full Text Available For the current study the Lazarian stress-coping theory and the appendant model of psychosocial adjustment to chronic illness and disabilities (Pakenham 1999 has shaped the foundation for identifying determinants of adjustment to ALS. We aimed to investigate the evolution of psychosocial adjustment to ALS and to determine its long-term predictors. A longitudinal study design with four measurement time points was therefore, used to assess patients’ quality of life, depression, and stress-coping model related aspects, such as illness characteristics, social support, cognitive appraisals and coping strategies during a period of two years. Regression analyses revealed that 55% of the variance of severity of depressive symptoms and 47% of the variance in quality of life at T2 was accounted for by all the T1 predictor variables taken together. On the level of individual contributions, protective buffering and appraisal of own coping potential accounted for a significant percentage in the variance in severity of depressive symptoms, whereas problem management coping strategies explained variance in quality of life scores. Illness characteristics at T2 did not explain any variance of both adjustment outcomes. Overall, the pattern of the longitudinal results indicated stable depressive symptoms and quality of life indices reflecting a successful adjustment to the disease across four measurement time points during a period of about two years.Empirical evidence is provided for the predictive value of social support, cognitive appraisals, and coping strategies, but not illness parameters such as severity and duration for adaptation to ALS. The current study contributes to a better conceptualization of adjustment, allowing us to provide evidence-based support beyond medical and physical intervention for people with ALS.

  2. The beta-decay of Al-22

    NARCIS (Netherlands)

    Achouri, NL; Santos, FDO; Lewitowicz, M; Blank, B; Aysto, J; Canchel, G; Czajkowski, S; Dendooven, P; Emsallem, A; Giovinazzo, J; Guillet, N; Jokinen, A; Larid, AM; Longour, C; Perajarvi, K; Smirnova, N; Stanoiu, M

    2006-01-01

    In an experiment performed at the LISE3 facility of GANIL, we studied the decay of Al-22 produced by the fragmentation of a Ar-36 primary beam. A beta-decay half-life of T-1/2 = 91.1 +/- 0.5ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma-de

  3. Response to de la Iglesia et al.

    Science.gov (United States)

    Yetish, Gandhi; Kaplan, Hillard; Gurven, Michael; Wood, Brian; Pontzer, Herman; Manger, Paul R; Wilson, Charles; McGregor, Ronald; Siegel, Jerome M

    2016-04-01

    We wish to respond to the commentary of de la Iglesia et al. [1]. Studies comparing sleep in different communities have different goals. One frequent goal has been to determine how sleep is affected by manipulating specific 'modern' conditions. Many studies have investigated the effect of artificial light and electronic entertainment. Such studies have clearly shown that light, particularly blue light, delays sleep onset [2]. Studying the effect of artificial light on sleep was not a goal of our study.

  4. Thermodynamic characterization of NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, C.A. [Battelle, 505 King Avenue, Columbus, OH 43201 (United States)], E-mail: alexandc@Battelle.org; Ogden, J.S.; Risser, S.M.; Wood, Van E. [Battelle, 505 King Avenue, Columbus, OH 43201 (United States)

    2009-05-15

    Thermodynamic properties of the high-stability intermetallic compound nickel aluminide, NiAl, have been determined from mass-spectrometric, weight-loss effusion, and calorimetric measurements, using samples from a single preparation with a composition determined to be Ni{sub 0.986}Al{sub 1.014}. Per mole of NiAl molecules, the specific heat capacity at room temperature of 298 K is 48.54 J . K{sup -1} . mol{sup -1}, with a linear temperature dependence of +0.0104 J . K{sup -2} . mol{sup -1}. At the same temperature, the enthalpy of formation is -133.7 kJ . mol{sup -1}, the entropy is about 53.8 J . K{sup -1} . mol{sup -1} and the enthalpy difference between room temperature and absolute zero is 7.97 kJ . mol{sup -1}. The Gibbs free-energy is -130.2 kJ . mol{sup -1} at T = 298 K, with a linear temperature dependence of +5.04 J . K{sup -1} . mol{sup -1}. The Debye temperature is 452 K, while the electronic density-of-states at the Fermi-level is about 0.29 states per eV-atom. The NiAl{sup +} ions were observed in the high-temperature mass spectra. Pressures for the gas at these temperatures were estimated and used with the results of quantum-mechanical calculations of total energy, specific heat, and entropy to calculate free-energy functions for the gas. These and additional results are compared with other measurements and discussed in terms of current theories of the electronic and structural properties of the compound.

  5. Crítica al funcionalismo normativista

    OpenAIRE

    2010-01-01

    El artículo gira en torno al modelo de pensamiento del funcionalismo «normativista» formulado por Günther Jakobs y de las bases metodológicas que han hecho desembocar su teoría de la pena en el ambiguo concepto del llamado «derecho penal del enemigo» como teoría de la excepción penal.

  6. Globale Entwikclung als Lernbereich in den Naturwissenschaften

    OpenAIRE

    Härtig, Hendrik; Bernholt, Sascha; Schroeter, Burkhard

    2014-01-01

    Mit dem Orientierungsrahmen für den Lernbereich Globale Entwicklung wurden Anregungen gegeben, die Themen nachhaltige Entwicklung und globale Entwicklung im Unterricht in allen Schulfächern aufzugreifen. Die drei naturwissenschaftlichen Schulfächer Biologie, Chemie und Physik haben sich bislang sehr unterschiedlich auf das Thema eingelassen. In der Biologiedidaktik finden sich sowohl Forschungsarbeiten als auch Unterrichtsvorschläge; für Chemie und insbesondere Physik existieren hingegen nur ...

  7. Influence of AlF3 and hydrothermal conditions on morphologies of α-Al2O3

    Institute of Scientific and Technical Information of China (English)

    FU Gao-feng; WANG Jing; KANG Jian

    2008-01-01

    Homogeneous α-Al2O3 platelets were synthesized by introducing AlF3 to alumina precursor.The effects of AlF3 additive on the phase transformation and morphology of the prepared α-Al2O3 platelets were investigated.The results show that a single phase of α-Al2O3 with an average particle size of 8μm can be obtained at 900℃ with 2% AlF3 additive.The transformation temperature decreasing IS attributed to introduction of Al3+ vacancy and to the formation of intermediate compound of AlOF,which is considered to accelerate the mass transportation from transitional Al2O3 to α-Al2O3.AlF3 concentration and hydrothermal temperature can also affect the morphology of α-Al2O3.When hydrothermal temperature is 120℃,the morphology of α-Al2O3 transforms from irregular to flat hexangular platelet with increasing AlF3 concentration.As hydrothermal temperature increases,the morphology of α-Al2O3 with 2% AlF3 additive changes from polyhedron to hexangular platelet and then to vermicular.

  8. ALS1 and ALS3 gene expression and biofilm formation in Candida albicans isolated from vulvovaginal candidiasis

    Directory of Open Access Journals (Sweden)

    Shahla Roudbarmohammadi

    2016-01-01

    Conclusion: The results attained indicated that there is an association between the expression of ALS1 and ALS3 genes and fluconazole resistance in C. albicans. A considerable percent of the isolates expressing the ALS1 and ALS3 genes may have contributed to their adherence to vagina and biofilm formation.

  9. Fracture toughness of Al-4%Mg/Al{sub 2}O{sub 3}p composites

    Energy Technology Data Exchange (ETDEWEB)

    Pestes, R.H. [Hewlett-Packard, Camus, WA 98607 (United States); Kamat, S.V. [Mechanical and Materials Engineering Department, Washington State University, Pullman, WA 99164-2920 (United States); Hirth, J.P. [Mechanical and Materials Engineering Department, Washington State University, Pullman, WA 99164-2920 (United States)

    1994-12-20

    Fracture toughness tests were carried out on Al-4%Mg/Al{sub 2}O{sub 3}p composites containing different sizes and volume fractions of alumina particulates. The results indicated that the fracture toughness was dependent on the interparticle spacing provided the particulate size was below a critical size. The critical particle size corresponds to the situation wherein the energy release rate on particulate cracking is sufficient to trigger dynamic unstable crack extension. ((orig.))

  10. „Der Islam begann als Fremder, und als Fremder wird er wiederkehren“

    DEFF Research Database (Denmark)

    Riexinger, Martin Thomas

    2015-01-01

    Muḥammad b. ʿAbd al-Wahhāb embeds in his Mukhtaṣar sīrat al-rasūl the biography of Muḥammad in an overarching vision of history that begins with Adam and ends in the Mongol period. In this cyclical concept the promulgation of Islam is followed by a relapse into shirk due to misdirected piety...

  11. Magnetism of UPtAl and UIrAl; LDA+U calculations

    Energy Technology Data Exchange (ETDEWEB)

    Rusz, Jan [Department of Electronic Structures, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic)]. E-mail: rusz@mag.mff.cuni.cz; Divis, Martin [Department of Electronic Structures, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic)

    2005-04-15

    We report on electronic structure calculations of UPtAl and UIrAl ternary uranium based intermetallic compounds. Calculations were performed in the framework of density functional theory using LDA+U exchange correlation potential. Full relaxation of U and J parameters was performed with the aim of obtaining correct total magnetic moments on uranium site. These parameters are then used in subsequent analysis of magnetic moments (including spin and orbital components) and hybridization effects.

  12. Liquidus Temperatures of System Na3AlF6-K3AlF6-AlF3 for Aluminum Electrolysis at Lower Temperature

    Institute of Scientific and Technical Information of China (English)

    WEI Chen-juan; LAI Yan-qing; LI Jie; TIAN Zhong-liang; WANG Jia-wei; ZOU Zhong; LIU Ye-xiang

    2011-01-01

    Liquidus temperatures in the molten salt system Na3AlF6-K3AlF6-AlF3 of interest for aluminum electrolysis were determined by thermal analysis method.The results were presented and an empirical equation describing liquidus temperatures for primary crystallization was derived t=1003.5-0.081 ×A2.3159-5.87×B0.657-0.024×A2.22×B1.14+0.035×A2.17×B1.084,where t is the liquidus temperature in degree Celsius,A denotes the mass fraction of AlF3 in system Na3AlF6-K3AlF6-AlF3,and B denotes K3A1F6/(Na3AlF6+K3AlF6)in mass(%,the value was defined as KR in this paper).The composition limitations are 0<w(AlF3)<30%,and 0<KR<50%.The isothermal diagram of molten salt system Na3AlF6-K3A1F6-AlF3 was obtained in this composition limitation.

  13. In-situ Synthesis of Ti3AlC2/TiC-Al2O3 Composite from TiO2-Al-C System

    Institute of Scientific and Technical Information of China (English)

    Jixin CHEN; Jialin LI; Yanchun ZHOU

    2006-01-01

    Ti3AlC2/TiC-Al2O3 composite was synthesized by a combustion reaction in TiO2-Al-C system. The effect of the compositions in raw materials on the products was investigated. Ti3AlC2/TiC-Al2O3 composite was obtained at the molar ratio of TiO2:Al:C=3.0:5.0~5.1:1.8~2.0. The reaction path for the 3TiO2-5Al-2C system was proposed. Al3Ti, Ti2O3, TiO, and δ-Al2O3 are found to be transitional phases. Finally,Ti3AlC2/TiC-Al2O3 composite forms at ~900℃ of furnace temperature. The measured Vickers hardness,fracture toughness, and flexural strength of the nearly dense sample from 3TiO2-5Al-2C are 13.3±1.1 GPa,5.8±0.3 MPa.m1/2, and 466±39 MPa, respectively.

  14. L'Hemisferic: Una ventana al mundo

    Directory of Open Access Journals (Sweden)

    Calatrava Valls, Santiago

    2000-12-01

    Full Text Available The "Hemisféric-Planetario" building is located in the center line East-West of the "Ciudad de las Artes y las Ciencias" complex, flanked by two rectangular lakes, in the north and in the south, respectively. In the East side we can find a promenade between the Museum and its south lake. Nevertheless its West side is virtual. and located in the area of the "Hermanos Marista 's" viaducto The building is visited, daily, by about 3.000 people, distributed between its 8 duties. The showing room holds 321 seats, four of those for wheel-chairs. The building has a possible room of 999 people (at the same time.El edificio Hemisféric-Planetarío está situado sobre el eje Este-Oeste del complejo de la Ciudad de las Artes y las Ciencias; está flanqueado por dos estanques rectangulares, al Norte y al Sur, respectivamente. Por el Este, un paseo limita la parcela con el Museo y su estanque Sur. El limite Oeste, sin embargo. es virtual y se encuentra en la proyección del viaducto de Hermanos Maristas. Este edificio es visitado diariamente por unos 3.000 personas, distribuyéndose en 8 funciones. La sala de proyección dispone de 321 butacas, con posibilidad de alojar 4 sillas de ruedas. La capacidad de acogida del edificio (al mismo tiempo es de 999 personas.

  15. Diet and dietetics in al-Andalus.

    Science.gov (United States)

    Salas-Salvadó, Jordi; Huetos-Solano, Maria D; García-Lorda, Pilar; Bulló, Mònica

    2006-08-01

    Al-Andalus society (711-1492) based its idea of health on the wisdom of Classical Greece, the Hippocratic-Galenic theories, as well as the Persian and Hindu cultures. The twelfth century in al-Andalus is considered to be the most prolific period for works of a scientific and technical nature. At the time, the main treatises on dietetics were written and this science reached its widest expression with such leading figures as Ibn Wāfīd, Avenzoar, Averroes and Maimonides, whose works revealed the first scientific knowledge on the nutritional processes of the human body. Diet was regarded as being essential for health and the prevention of disease. Dietary guidelines were written for different age groups, different body types and different seasons of the year. The amount of food to be ingested, the number of meals recommended and the order in which the food should be consumed were all issues that were discussed. A variety of foods were thought to have medicinal properties, some of which are known today. The diet in al-Andalus was varied and very probably made a substantial contribution to the origin of the present-day Mediterranean diet, rich in olive oil, wholemeal cereals, fruit and vegetables, fish, lamb, poultry, nuts and spices. We also find that many of the terms in current use in diet and agriculture are a living testimony to the Arabic influence, as are many of the dishes of our varied Mediterranean gastronomy.

  16. Keanekaragaman dalam al-Qur’an

    Directory of Open Access Journals (Sweden)

    Muhammad Chirzin

    2011-04-01

    Full Text Available The diversity of race, language, class, and culture is a wealth; basically, it is a beautiful gift in this life. However, the reality is precesely the social conflict among the society. This article explores the issue of diversity contained in al Qur’an. Some of the key themes included: diversity as sunnatullah, diversity in unity, religious and ethnic diversity, and diversity of professions. Al Qur’an has mentioned several groups of religious believers and provided guidance association order among religious believers. Religious diversity certainly makes Muslim necessitates acknowledging and respecting other religion save Islam. Al Qur’an has mentioned also a variety of occupations based on interests, talents, expertise, and particular skills. The fragmentation and understanding diversity have caused by egoism and truth claiming of each group and individual, but no one has knowledge covering everything from different sides or corners. Above all knowledge is the Almighty owner off all knowledge. With feeling most true someone or group tends to feel the best and have the right to insult any others. That is the base of the dispute and spiritual decline. Mukmin has to preserve the noble character in association, and keep away from bad manner. Among mukmin must love each other and maintain good manners. Finally, this study is intended to promote the establishment of harmony, peace and happiness of living together.

  17. Resistencia al esfuerzo cortante en rellenos sanitarios

    Directory of Open Access Journals (Sweden)

    Eimar Andrés Sandoval-Vallejo

    2015-01-01

    Full Text Available Los rellenos sanitarios son obras ingenieriles conformadas con un material específico, cuyas propiedades de resistencia al cor te pueden determinarse de manera similar a la de un material geotécnico. Este artículo presenta resultado s de un programa experimental r ealizado con el fin de obtener los paráme tros de resistencia al corte de l relleno sanitario Presidente en el Valle del Cauca (Colombia . El programa experimental involucró ensayos d e corte directo no consolidado no drenado (UU sobre muestras reconstituidas en laboratorio. L a variación del ángulo de fricción interna y de la cohesión, como una funci ón del peso específico, profundidad, y tiempo de descomposición del relleno fue evaluada. También se compararon los resu ltados con valores internacionales usados para diseñ o. Los resultados mostraron un a marcada influencia del tiempo de descom posición en la resistencia al co rte. También se encontró ciert a dependencia con la profundidad. Los parámetros de resistencia obtenidos se encuentran dentro de ran gos internacionales recomendados para diseño.

  18. Thermodynamic properties and mixing thermodynamic parameters of Ba-Al, Mg-Al, Sr-Al and Cu-Al metallic melts

    Institute of Scientific and Technical Information of China (English)

    张鉴

    2004-01-01

    Application of equations of mixing thermodynamic parameters formulated on the basis of the coexistence theory of metallic melts in Ba-Al, Mg-Al, Sr-A1 and Cu-Al melts leads to fruitful results that not only the evaluated mass action concentrations agree well with the measured activities, but also the calculated mixing thermodynamic parameters are quite coincident with the experimental values. Moreover, the calculated mass action concentrations strictly obey the mass action law. The evaluated mixing thermodynamic parameters have very fine regularity: the mixing free energy is composed of standard free formation energies of all compounds and chemical potentials of all structural units at equilibrium; the mixing enthalpy consists of standard formation enthalpies of all compounds; the mixing entropy is composed of standard entropies of all compounds and configuration entropies of all structural units at equilibrium. As the equations of mixing thermodynamic parameters formulated are widely applicable to metallic melts involving compound formation, they can be used as the second practical criterion to determine whether thermodynamic models of metallic melts are correctly formulated.

  19. Studies on Al Kidirate and Kapoeta meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, A.M. [Sudan Atomic Energy Commission, Khartoum (Sudan); Khangi, F. [Sudan Atomic Energy Commission, Khartoum (Sudan); Ibrahim, A. [Sudan Atomic Energy Commission, Khartoum (Sudan); Yousif, A.A. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman); Worthing, M.A. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman); Rais, A. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman); Elzain, M.E. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman); Brooks, C.K. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman); Sutherland, H.H. [Coll. of Science, Sultan Qaboos Univ., Alkhoud (Oman)

    1994-11-01

    Moessbauer spectroscopy (20-300 K), magnetic susceptibility measurements (77-350 K), scanning electron microscopy and X-ray diffraction experiments have been performed on two meteorite samples: one from an old fall (Kapoeta) and another from a very recent fall (Al Kidirate). The two specimens differ in their mineralogy. Chondrules appear to be absent in Kapoeta and it is probably a pyroxene-plagioclase achondrite with ferrohypersthene as the most abundant mineral. On the other hand, the Al Kidirate meteorite is an ordinary chondrite and the specimen consists of olivine, orthopyroxene, troilite and kamacite. The Moessbauer measurements confirm the above characterization, showing a paramagnetic doublet for the Kapoeta sample and at least two paramagnetic doublets and magnetic sextets for the Al Kidirate specimens. The former were assigned to Fe in pyroxene sites, while the latter was assigned to Fe in pyroxene, olivine, Fe-S and Fe-Ni alloys. The difference in the mineralogy of the two meteorites has also been reflected in the temperature-dependent magnetic susceptibility. The magnetization and the hyperfine interaction parameters will be discussed in relation to the mineralogy. (orig.)

  20. De la vigilancia convencional al monitoreo participativo

    Directory of Open Access Journals (Sweden)

    Jaime Breilh

    Full Text Available La necesidad de transformar el monitoreo de la salud de un instrumento funcional al sistema dominante de poder en una herramienta del poder colectivo, y de negociación del desarrollo de la salud laboral y el bienestar, implica la urgente transformación de la vieja vigilancia epidemiológica en un monitoreo participativo. Debe superarse el sistema convencional de información en salud, que observa fundamentalmente los "factores de enfermedad" y sus efectos mórbidos aislados, invisibilizando los procesos de determinación integrales. Este trabajo analiza el proceso de derrota de los derechos sociales y laborales, lo cual sitúa el desafío planteado en un escenario de profundo retroceso social y asalto a los derechos conquistados por los/as trabajadores/as en años de lucha. Con el propósito de esclarecer dicho argumento, al autor comienza contrastando los modelos de vigilancia clásicos, algunas propuestas transicionales, hasta arribar al monitoreo participativo. La aplicación de la categoría "perfil epidemiológico" permite sistematizar los dominios y dimensiones del monitoreo y establecer los sujetos sociales de esa mirada crítica e intercultural del pueblo sobre su salud, mediante la construcción de una matriz de procesos críticos.

  1. Evaluation of aerial microbial pollutants in Al-Haram Al-Nabawi during pilgrimage of 2013.

    Science.gov (United States)

    Alananbeh, Kholoud M; Boquellah, Nahla; Kaff, Nadia Al; Ahmadi, Majid Al

    2017-01-01

    Al-Madinah Al-Munawwarah is the second holiest site in Islam. The possibility of new emerging microbes is valid due to the increased number of pilgrims. The objectives of the current study were to estimate the numbers of fungi and bacteria inside and outside Al-Haram Al-Nabawi and to find whether new bacterial and fungal species have emerged compared to previous studies. Air samples were collected twice a day from 12 spots and four directions during the pilgrim year of 2013 for four consecutive weeks by using the sedimentation method. Thirty five genera and fifty eight species were identified. The most recovered bacterial genera were Staphylococcus, Micrococcus, Bacillus, and Dermacoccus with 32.47%, 18.18%, 12.85%, and 11.23%, respectively. Fifty nine isolates of fungi were molecularly identified. Aspergillus species had the highest percentage (78%). The other fungal genera identified (Alternaria triticina, Emericella nidulans, Emericella striata, Mucor circinelloides, Penicillium chrysogenum, Penicillium minioluteum, Rhizopus arrhizus, Rhizopus oryzae, and Syncephalastrum racemosum) had less than 5% frequency. In places such as Al-Haram Al-Nabawi, a large and crowded public (millions) exist especially during pilgrimages and Ramadan, thus, exposure to microorganisms is high. On the other hand, microorganism infectivity depends on many factors including their virulence, landing site, and person's immunity. For those reasons, many aspects should be considered to avoid aerosol contaminants.

  2. Fabrication and Characterization of Al/p-CuInAlSe2 Thin Film Schottky Diodes

    Directory of Open Access Journals (Sweden)

    Usha Parihar

    2013-05-01

    Full Text Available Al/p-CuInAlSe2 polycrystalline schottky diodes fabricated by flash evaporation method were undertaken for their electrical analysis at room temperature. Diode parameters of the undertaken diodes were then derived from the current-voltage (I-V as well as capacitance-voltage (C-V characteristics. It has been observed that the schottky barrier height deduced from the room temperature I-V is lower to that obtained from the C-V characteristics and is attributed to the fact that I-V analysis includes both the image force and dipole lowering effects and is also reduced by the tunneling and leakage currents. The slope variation of the frequency dependent C – 2-V characteristics for the Al/p-CuInAlSe2 Schottky diode at varying frequency values from 50 kHz to 1 MHz suggests a large density of slow traps or interface states at the M-S junction. As emerging from the parameters values energy band diagram of Al and P-CuInAlSe2 has been reconstructed.

  3. Preparation of Al- AlN Bonded Corundum Based Refractories by in-situ Reaction

    Institute of Scientific and Technical Information of China (English)

    ZHU Boquan; FANG Binxiang; ZHANG Wenjie

    2008-01-01

    The Al-AlN bonded corundum based refractories was synthesized with the starting materials of fused alu-mina and metallic aluminium in nitrogen atmosphere through in-situ reaction. The study indicated that with the addition of 14% metallic aluminium (13% of Al powder and 1% of Al fiber) , the material nitridized at 1 100 ℃ for 3 h has excellent physical properties. It is found that a massive quantity of AlN in the forms of both whiskers" and hexagon pellet particles is formed, and a large quantity of Al remained in the matrix. This multiple bonding system resulted in the excellent me-chanical properties of the material. It is also found that the hydration tendency of the prepared material is inhib-ited, and the material exhibited excellent thermal shock resistance. The nature of protective oxidation of the bonding system is characterized. Thus, this material may become a new candidate of carbon-free sliding plate material for continuous casting.

  4. A comparative wear study on Al-Li and Al-Li/SiC composite

    Science.gov (United States)

    Okumus, S. Cem; Karslioglu, Ramazan; Akbulut, Hatem

    2013-12-01

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms-1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  5. Nanoindentation studies of ex situ AlN/Al metal matrix nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Fale, Sandeep; Likhite, Ajay; Bhatt, Jatin, E-mail: jatinbhatt@mme.vnit.ac.in

    2014-12-05

    Highlights: • Formation of in-situ phases nucleated on AlN particles strengthens the matrix. • Formation of in-situ phases increases with AlN content in nanocomposites. • Stronger in-situ phases results in increased hardness and modulus of elasticity. - Abstract: Nanocrystalline Aluminium nitride (AlN) powder is dispersed in different weight ratio in Aluminum matrix to fabricate metal matrix nanocomposite (MMNC) using ex situ melt metallurgy process. The synthesized Al–AlN nanocomposites are studied for phase analysis using high resolution scanning electron microscopy (FEG-SEM) and for hardness behavior using microindentation and nanoindentation tests. Quantitative analysis of the oxide phases is calculated from thermodynamic data and mass balance equation using elemental data obtained from energy dispersive spectroscopy (EDS) results. Role of oxide phases in association with AlN particles is investigated to understand the mechanical behavior of composites using nanoindentation tester. Load–displacement profile obtained from nanoindentation test reveals distribution of oxide phases along with AlN particle and their effect on indent penetration.

  6. Evaluation of aerial microbial pollutants in Al-Haram Al-Nabawi during pilgrimage of 2013

    Directory of Open Access Journals (Sweden)

    Kholoud M. Alananbeh

    2017-01-01

    Full Text Available Al-Madinah Al-Munawwarah is the second holiest site in Islam. The possibility of new emerging microbes is valid due to the increased number of pilgrims. The objectives of the current study were to estimate the numbers of fungi and bacteria inside and outside Al-Haram Al-Nabawi and to find whether new bacterial and fungal species have emerged compared to previous studies. Air samples were collected twice a day from 12 spots and four directions during the pilgrim year of 2013 for four consecutive weeks by using the sedimentation method. Thirty five genera and fifty eight species were identified. The most recovered bacterial genera were Staphylococcus, Micrococcus, Bacillus, and Dermacoccus with 32.47%, 18.18%, 12.85%, and 11.23%, respectively. Fifty nine isolates of fungi were molecularly identified. Aspergillus species had the highest percentage (78%. The other fungal genera identified (Alternaria triticina, Emericella nidulans, Emericella striata, Mucor circinelloides, Penicillium chrysogenum, Penicillium minioluteum, Rhizopus arrhizus, Rhizopus oryzae, and Syncephalastrum racemosum had less than 5% frequency. In places such as Al-Haram Al-Nabawi, a large and crowded public (millions exist especially during pilgrimages and Ramadan, thus, exposure to microorganisms is high. On the other hand, microorganism infectivity depends on many factors including their virulence, landing site, and person’s immunity. For those reasons, many aspects should be considered to avoid aerosol contaminants.

  7. TEM characterization of Al-C-Cu-Al{sub 2}O{sub 3} composites produced by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Beltran, A. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico); Gallegos-Orozco, V. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico); Estrada-Guel, I. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico); Bejar-Gomez, L. [Universidad Mich. de San Nicolas de Hidalgo, Edif. ' W' , C.U., C.P. 58000, Morelia, Mich. (Mexico); Espinosa-Magana, F. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico); Miki-Yoshida, M. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico); Martinez-Sanchez, R. [Centro de Investigacion en Materiales Avanzados (CIMAV), Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih. (Mexico)]. E-mail: roberto.martinez@cimav.edu.mx

    2007-05-31

    Novel Al-based composites (Al-C-Cu-Al{sub 2}O{sub 3}) obtained by mechanical milling (MM), were characterized by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). Analyses of composites were carried out in both, the as-milled and the as-sintered conditions. C nanoparticles were found in the as-milled condition and Al{sub 2}O{sub 3} nanofibers were found in as-sintered products, as determined by EELS. C and Cu react with Al to crystallize in Al{sub 3}C{sub 4} and Al{sub 2}Cu structures, respectively.

  8. Aspectos biopsicosociales asociados al embarazo adolescente

    Directory of Open Access Journals (Sweden)

    Regina Cogollo Jiménez

    2012-12-01

    Full Text Available Introducción: El embarazo en la adolescencia, es un evento inesperado, sorpresivo. Este artículo establece la importancia de identificar los aspectos biopsicosociales asociados al embarazo adolescente en las embarazadas asistentes al programa de Control Prenatal de una Empresa Social del Estado de nivel 1 en Montería en 2009, para comprender las actitudes y los comportamientos asociados a esta etapa tan temprana. Materiales y Métodos: Es un estudio descriptivo, cuantitativo, de corte transversal. Población y muestra: 30 adolescentes embarazadas asistentes al Programa, el muestreo por conveniencia. Se utilizó la encuesta y la observación directa, previa autorización del Director de la empresa. Resultados: Caracterización de la población: predominó la edad de 15 a 19 años (adolescencia tardía, uniones libres, baja escolaridad debido a la deserción escolar, ingreso económico menor al salario mínimo legal vigente. Aspectos Biológicos: la menarquía a temprana edad (9 a 14 años, y en ella la mitad de los embarazos. La mayoría de los segundos embarazos terminaron en parto, la minoría en cesárea y aborto. La captación para los controles prenatales fue tardía, algunas no cumplieron con las citas programadas. Aspectos Psicológicos: inestabilidad con la pareja al enterarse del embarazo, tuvieron soporte familiar moral y económico, abandonaron sus estudios y presentaron malestares como estrés, depresión y tristeza. Aspectos Sociales: predominó la convivencia con la familia extensa. Hubo aceptación en el colegio y en los amigos. Discusión y Conclusiones: Se plantean estrategias para disminuir estos aspectos: elaboración de una cartilla sobre “Cuidado de la adolescente embarazada”, creación de espacios de reflexión, jornadas lúdicas educativas, entre otros. (Rev Cuid 2012; 3(3:385-93.Palabras clave: Embarazo en Adolescencia, Bienestar Materno, Atención Prenatal. (Fuente: De

  9. Study on Interface between Sub-micron Particles and Matrix n Al2O3p/Al Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The microstructural characteristic of 1070Al matrix composites reinforced by 0.15 μm Al2O3 particles whose volume fraction was 40% was investigated by TEM and HREM. The results showed that the interface between the matrix and reinforcements was clean and bonded well, without any interfacial reaction products. There were some preferential crystallographic orientation relationships between Al matrix and Al2O3 particle because of the lattice imperfection on the surface of Al2O3 particles.

  10. Motivasi Berpikir Menurut al-Qur’an

    Directory of Open Access Journals (Sweden)

    Dwi Andriyani

    2016-07-01

    Full Text Available Kitab Suci Al-Qur’an merupakan kitab Allah yang diturunkan kepada umat manusia sebagai petunjuk bagi kita semua, yang mana diturunkan kepada umat Nabi Muhammad Saw mulai dari berabad-abad yang lalu, hingga sampai sekarang ini. Al-Qur’an di dalamnya banyak sekali mengandung isyarat ilmiah yang berguna bagi umat manusia. Oleh karena itu, sebagai makhluk Allah yang dikarunia akal pikiran, sudah seharusnya menjadi tugas kita untuk mengungkap apa yang ada di dalam al-Qur’an yang menjadi isyarat ilmiah bagi kemajuan ilmu pengetahuan. Al-Qur’an banyak memberikan motivasi bagi umat manusia, terutama motivasi berpikir. Berpikir adalah olah kerja otak yang yang berfungsi mencari hakekat dari sesuatu. Namun, dalam al-Qur’an berpikir juga tidak semuanya dilakukan oleh akal pikiran, melainkan juga dapat dilakukan dengan hati. Ketika mengkaji lebih dalam mengenai berpikir, maka akan didapatkan beberapa lafadz yang mempunyai pengertian yang sama, yaitu berpikir. Seperti lafadz nazara, tadabbara atau tadabbur, tafakkara atau tafakkur, faqiha atau fiqh atau tafaqquh, tazakkara, dan faham. Semua yang disebutkan di atas adalah mempunyai pengertian yang hampir sama. Membangkitkan motivasi berpikir dalam mengkaji ayat-ayat al-Qur’an sangatlah bermanfaat dalam menambah wawasan, dan juga dapat menambah keimanan kita kepada Allah Swt. Beberapa penemuan yang ada pada saat sekarang ini merupakan bukti dari kebenaran al-Qur’an, isyarat ilmiahnya dapat dibuktikan dengan beberapa penemuan di bidang ilmu pengetahuan.   The Holy Qur'an is a book of God revealed to mankind as a guide for all of us, which was revealed to the Prophet Muhammad's people from many centuries ago until now. The Qur'an contains a lot of useful scientific cue for mankind. Therefore, as a creature of Allah endowed with a mind, it should be our duty to reveal what is in the Qur’an becomes the scientific cue to the advancement of knowledge. The Holy Qur'an has provided motivation for

  11. Deutsch als "leicht zu erlernende Fremdsprache"

    Directory of Open Access Journals (Sweden)

    Kurtz, Gunde

    2005-01-01

    Full Text Available The goal of this paper is to encourage the search for accessible language features and teaching and learning facilitators which can ease the way into German as a Foreign Language (DaF.The paper begins with a terminological discussion, followed by a first model of the most important factors concerning the initial entry into FL territory. After a short review on previous work in this area, I consider methods for utilising knowledge of accessible language features and teaching and learning facilitators. Finally, suspected facilitating features - which have come to light through research as well as classroom observations – are exemplified. These, however, are to be understood as working hypotheses and thus still 'under construction'.Through this paper, I would like to invite other researchers to consider a new perspective on DaF with the intention of changing the status quo:"Applied linguistics is not simply a matter of matching up findings about language with pre-existing problems but of using findings to explore how the perception of problems might be changed. It may be that when problems are reformulated from a different point of view they become more amenable to solution. This changed perception may then, in turn, have implications for linguistics." (Cook : 2003: 10My goal will have been achieved when the focus of this paper becomes a motivation for improving DaF teaching ("problems [...] become more amenable to solution" - and, should it lead to "implications for linguistics", so much the better.Ziel dieses Beitrages ist, eine umfassende Suche nach leichten Stellen und Erleichterungen beim Zugang zum Deutschen als fremder Sprache anzuregen.Nach Begriffsklärung und einem ersten Vorschlag zu den für die Zugänglichkeit einer Sprache ausschlaggebenden Faktoren (1 sowie einem kurzen Überblick über Fundstücke zum Thema (2 steht die Rolle der praktischen Umsetzung von Erkenntnissen als Hauptinstrument für den Bereich der Erleichterungen und

  12. Studies of Al metabolism in animal by accelerator mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    WangNa-Xiu; ZhuHan-Min; 等

    1997-01-01

    The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with 26Al,killed after 5,10,15,25,and 35d and 26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of 26Al,and the existed Al content and dementia was studied.

  13. Effect of the composition of Al-Li alloys on the quantitative relation between the δ'(Al3Li), S1(Al2MgLi), and T1(Al2CuLi) phases

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Grushin, I. A.; Knyazev, M. I.; Khokhlatova, L. B.; Alekseev, A. A.

    2015-01-01

    Al-Li alloys are considered. A quantitative approach to the determination of the ratio of the fractions of the binary and ternary intermetallic phases in Al-Mg(Cu)-Li alloys is developed on the basis of chemical and phase composition balance equations and the experimentally measured lattice parameter of the α solid solution. The ratio of the fractions of the δ'(Al3Li) and S1(T1) phases in Al-Mg(Cu)-Li alloys is shown to be determined by the ratio of the mole fractions of Li and Mg(Cu). Equations are proposed for calculating the weight fractions of the S1(Al2MgLi), T1(Al2CuLi) and δ'(Al3Li) phases in domestic and foreign Al-Mg-Li alloys 1420, 1424, 5090 and Al-Cu-Li alloys 1440, 1460, 1461, 1441, 1469, 2090, 2095, 8090, and Weldalite 049.

  14. High-efficiency of AlInGaN/Al(In)GaN-delta AlGaN quantum wells for deep-ultraviolet emission

    Science.gov (United States)

    Saidi, Hosni; Ridene, Said

    2016-10-01

    Band structure and optical gain properties of AlInGaN/AlInGaN-delta-AlGaN quantum wells for deep-ultraviolet light emitting and lasers diodes with wavelength λ ∼229 nm and TE-polarized optical gain peak intensity ∼1.7 times larger than the conventional AlInN-delta-GaN was proposed and investigated in this work. The active region is made up of 20 Å staggered Al0.89In0.03Ga0.08N/Al0.8In 0.01Ga0.19N layers with a 3 Å Al0.46Ga0.54N delta layer. The use of the quaternary AlInGaN well layer permits the independent control of the band gap and the lattice parameter, so that the internal electric field induced by polarizations can be reduced and interband transition energy increases. Therefore, we can predict that the optical performance of the AlInGaN-delta-AlGaN is more convenient for an emission in the deep-ultraviolet than that of the conventional AlInN-delta-GaN-based quantum wells.

  15. Gaussian density-functional study for small neutral (Al n ), positive (Al{/n +}) and negative (Al{/n -}) aluminium clusters ( n=2 5)

    Science.gov (United States)

    Calaminici, Patrizia; Russo, Nino; Toscano, Marirosa

    1995-12-01

    The structures and properties of Al n , Al{/n +}, Al{/n -} ( n=1,5) clusters have been investigated by using the Linear Combination of Gaussian Type Orbitals (LCGTO) method, considering Local (LSD) and Non Local (NLSD) Spin Density Approximations and employing a Model Core Potential (MCP) that allows the explicit treatment of 3 s 2 3 p 1 valence electrons. For each system different geometrical structures and electronic states have been considered. For Al3, Al{3/+}, Al{3/-} the most stable geometry proved to be the equilateral triangle ( D 3 h ). Al4 and Al{4/+} prefer the rhombus ( D 2 h ) structure, while the corresponding anion prefers the square ( D 4 h ) one. The trapezoidal form ( C 2 v ) is the most stable isomer for Al5, Al{5/+} and Al{5/-} clusters. The analysis of vibrational frequencies shows that these structures are minima in the potential energy surface. The binding energies ( D e), the adiabatic ionization potentials (IP) and electron affinities (EA), the chemical potentials or absolute hardnesses (η) and electronegativities (χ) have been computed. Results are in good agreement with the available experimental data and the previous high level theoretical computations.

  16. Effect of nitrogen incorporation into Al-based gate insulators in AlON/AlGaN/GaN metal-oxide-semiconductor structures

    Science.gov (United States)

    Asahara, Ryohei; Nozaki, Mikito; Yamada, Takahiro; Ito, Joyo; Nakazawa, Satoshi; Ishida, Masahiro; Ueda, Tetsuzo; Yoshigoe, Akitaka; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

    2016-10-01

    The superior physical and electrical properties of aluminum oxynitride (AlON) gate dielectrics on AlGaN/GaN substrates in terms of thermal stability, reliability, and interface quality were demonstrated by direct AlON deposition and subsequent annealing. Nitrogen incorporation into alumina was proven to be beneficial both for suppressing intermixing at the insulator/AlGaN interface and reducing the number of electrical defects in Al2O3 films. Consequently, we achieved high-quality AlON/AlGaN/GaN metal-oxide-semiconductor capacitors with improved stability against charge injection and a reduced interface state density as low as 1.2 × 1011 cm-2 eV-1. The impact of nitrogen incorporation into the insulator will be discussed on the basis of experimental findings.

  17. AlGaN nanocolumns and AlGaN/GaN/AlGaN nanostructures grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, J.; Sanchez-Garcia, M.A.; Ulloa, J.M.; Calleja, E. [Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Sanchez-Paramo, J.; Calleja, J.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Jahn, U.; Trampert, A.; Ploog, K.H. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2002-12-01

    This work reports on the characterization of hexagonal, single crystal AlGaN nanocolumns with diameters in the range of 30 to 100 nm grown by molecular beam epitaxy on Si(111) substrates. The change of the flux ratio between the Al and the total III-element controls the alloy composition. The Al composition trend versus the Al flux is consistent both with the E{sub 2} phonon energy values measured by inelastic light scattering and the luminescence emission peaks position. High quality low dimensional AlGaN/GaN/AlGaN heterostructures with five GaN quantum discs, 2 and 4 nm thick, embedded into the AlGaN columns, were designed in order to study the quantum confinement effects. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  18. Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyong June [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule of mixtures. A quantitative relationship between UTS and deformation true strain was determined. X-ray diffraction data on transformation of Al + Ca microstructures to Al + various Al-Ca intermetallic compounds were obtained at the Advanced Photon Source at Argonne National Laboratory. Electrical conductivity was measured over a range of true strains and post-deformation heat treatment schedules.

  19. RESEARCH ON ELECTROCHROMIC PROPERTIES OF Al2O3/ B-Al-NiO-BASED FILM%Al2O3/B-Al-Nio薄膜电致变色性能的研究

    Institute of Scientific and Technical Information of China (English)

    楼贤春; 周学东; 曾涛

    2009-01-01

    采用溶胶-凝胶法制备了B-Al-Nio和Al2O3/B-Al-NiO复合薄膜.采用扫描电镜,电化学测试和透过率测试分析Al2O3薄膜并对B-Al-NiO的变色性能和稳定性进行分析和表征.结果表明Al2O3薄膜对NiO基薄膜的变色效果影响不大,同时有效提高NiO基薄膜的稳定性.

  20. 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.