WorldWideScience

Sample records for presion al simulador

  1. The wellbore simulator SIMU1999; El simulador de pozos SIMU1999

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Upton, Pedro [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    into a friendly Windows 95 environment for the user. Up to date, results obtained through the application of SIMU 1999 on multiple wells, covering a broad extent of thermal conditions, have been good enough from the engineering point of view, Nevertheless, updating of the simulator performance, but also looking for extending its application field. [Spanish] En este trabajo se describen brevemente las caracterIticas operacionales y algoritmicas del simulador de pozos SIMU1999. En general, la reproduccion de las condiciones termodinamicas registradas en el interior de los pozos, es su principal objetivo. El simulador utiliza un modelo de flujo homogeneo que incorpora las teorias fundamentales de la mecanica de fluidos y permite el manejo de mezclas bifasicas tricomponentes. Estas mezclas incluyen a los principales constituyentes que aparecen en la produccion de fluidos geotermicos (H{sub 2}O-NaCl-CO{sub 2}). SIMU1999 utiliza un factor de friccion para flujos bifasicos deducido a partir de 64 pruebas de produccion efectuadas en 45 pozos diferentes. Mas de 324 datos de caidas de presion y 648 valores de temperatura se obtuvieron a partir de estas pruebas. Las mediciones se tomaron principalmente con registradores del tipo mecanico (Kuster), sin embargo, algunas de ellas provinieron de registradores de tipo electronico (Hot Hole y Pruett). El factor de friccion se calcula a partir del numero de Reynolds de la presion del fluido y de la calidad del vapor, por lo que es independiente de la identificacion previa del patron de flujo. Los datos de produccion disponibles abarcaron entalpias especificas desde 650 hasta 2 780 kj/kg, presiones que van de los 0.4 a los 14 MPa, y temperaturas entre 110 y 340 grados centigrados. El codigo computacional de SIMU1999 fue escrito en Fortran 90 y genera un archivo ejecutable ligeramente mayor a 1 Mb. El programa actualmente consta de cuatro partes: el simulador de pozos; una salida grafica para analizar por pantalla los resultados de la

  2. Simulador electromagnético basado en FDTD

    OpenAIRE

    Inclan Alonso, Jose Manuel

    2012-01-01

    El presenta trabajo fin de master tiene como objetivo el desarrollo de un simulador electromagnético basado en FDTD. El simulador incluye fronteras abiertas basadas en PML y transformada de campo cercano a lejano en el dominio del tiempo.

  3. Investigación en materiales sometidos a altas presiones

    Directory of Open Access Journals (Sweden)

    Juan Carlos Fallas

    2010-10-01

    Full Text Available El estudio de materiales sometidos a altas presiones es un tema de profundo interés en el campo científico e ingenieril actual. Diferentes análisis experimentales permiten descubrir los efectos que esta condición genera en la estructura molecular de un determinado compuesto.La implementación de la celda de diamante para altas presiones ha revolucionado este tema en las últimas décadas, al ser una herramienta vital en el desarrollo de estas pruebas. Presiones superiores, inclusive a los 20 Gpa, pueden ser generadas con este artefacto.Adicionalmente, la posibilidad de caracterizar muestras bajo estos parámetros y la inclusión de otras variables, como altas temperaturas, ofrecen un ambiente propicio para la evaluación de materiales bajo condiciones extremas.Este artículo explica los fundamentos básicos de la ciencia de materiales a altas presiones. Aspectos relevantes acerca de la celda de diamante y de la ejecución de experimentos son tratados en diferentes apartados. Se quiere compartir los alcances que esta disciplina posee, así como diferentes resultados que se han logrado en varias aplicaciones.Investigaciones en materiales para el almacenamiento de hidrógeno y energía, así como la simulación de condiciones presentes a muy altas profundidades en la Tierra, son casos que se tomaron en cuenta para ejemplificar áreas donde existen aplicaciones sustanciales.

  4. Simulador gráfico de Movimiento Armónico como instrumento para integrar conocimientos

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    Bongianino, Ruben

    2012-01-01

    Full Text Available La incorporación y uso adecuado de las TIC‟s durante el proceso de enseñanza-aprendizaje puede convertirse en un instrumento que ayuda a lograr aprendizajes significativos por un lado al construir el código fuente de un simulador, y por otro cuando se lo utiliza realizando experiencias virtuales. El trabajo presenta el desarrollo de un instrumento virtual de aprendizaje para ser utilizado como un simulador de un sistema mecánico aplicado en este caso sobre una masa, un resorte y un amortiguador (Simulador_MRA, con el objetivo de facilitar la incorporación de temas conceptuales del área mediante la realización de distintas experiencias. Durante las mismas se visualizan en la pantalla en tiempo real el movimiento de la masa y del resorte conjuntamente con las gráficas asociadas a la posición, velocidad, aceleración, y energías del sistema en función del tiempo. Las simulaciones se realizan en lenguaje Java, a través de un software para tal fin (Easy Java Simulations. A su vez se analizan las ventajas en la realización y utilización del Simulador_MRA frente a otros similares que se encuentran disponibles en la red.

  5. DESARROLLO DE UN SIMULADOR DE EDIFICIO CON PARÁMETROS VARIABLES

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    Andrés Enrique Rosso Mateus

    2009-01-01

    Full Text Available Este artículo expone la metodología de implementación de un simulador de edifi cio teniendo en cuenta factores de desarrollo como la escalabilidad del software, su ciclo de desarrollo y los detalles matemáticos usados para el modelamiento del sistema.Muestra además una metodología sencilla y efi caz para la simulación de cualquier tipo de sistema, en la cual se exponen las librerías de programación que se encontraron más útiles para este tipo de desarrollo. Este simulador representa un edifi cio real con todas las características y variables que interesan para el caso y se pretende usar para probar algoritmos de control para grupos de elevadores [10]. La arquitectura del simulador permite acoplar cualquier algoritmo de control que siga el estándar propio del simulador, se muestran como ejemplo dos algoritmos de control los cuales son ingresados en el simulador para probar su desempeño [10]. El simulador permite generar reportes estadísticos del desempeño de los controladores usados, estos reportes son útiles a la hora de comprobar la efi ciencia de estos y de comparar cuantitativamente el funcionamiento entre ellos.

  6. Simuladores para el aprendizaje y entrenamiento en vela

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    Jordi Renom Pinsach

    2006-06-01

    Full Text Available El objetivo de este artículo es revisar y proporcionar una clasificación general de los simuladores empleados para la enseñanza y entrenamiento en Vela. Los simuladores de navegación son una manera útil e interactiva para solucionar muchos problemas en el proceso de enseñanza y aprendizaje de la Vela. Ayudan a comprender los principios de la navegación empleando diferentes materiales y maneras de reproducir los efectos técnicos a bordo de un velero o una tabla a Vela. Diversos países y organizaciones de Vela acostumbran a aplicar estos recursos como un importante medio didáctico en actividades de interior. No obstante, este tipo de dispositivos son menos frecuentes en las escuelas de vela españolas. Desde los artefactos simples en tierra hasta los modernos simuladores virtuales de navegación este trabajo revisa una muestra representativa de los principales tipos de simuladores a fin de destacar sus utilidades en entornos de enseñanza aplicados.

  7. Simulator of a geotermoelectric unit for the training of operators; Simulador de una unidad geotermoelectrica para entrenamiento de operadores

    Energy Technology Data Exchange (ETDEWEB)

    Tavira Mondragon, Jose Antonio; Lopez Aguilera, Diana Monica; Roldan Villasana, Edgardo Javier; Rodriguez Lozano, Saul [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    The use of simulators replica in real time for operators training has demonstrated to be one of the best forms to enable the personnel of the Comision Federal de Electricidad (CFE). This article shows the basic characteristics of a simulator replica of the Cerro Prieto geotermoelectric power station of Baja California. It is expected that with this simulator 400 people between operators, shift superintendents and operation and maintenance auxiliary personnel become qualified. [Spanish] El uso de simuladores replica en tiempo real para entrenamiento de operadores de centrales generadoras ha demostrado ser una de las mejores formas de capacitar al personal de la Comision Federal de Electricidad (CFE). Este articulo muestra las caracteristicas principales de un simulador replica de la central geotermoelectrica de Cerro Prieto Baja California. Se espera que con este simulador se capaciten 400 personas entre operadores, superintendentes de turno y auxiliares de operacion y mantenimiento.

  8. Presiones medidas en la base de una losa de fondo con juntas paralelas al flujo en un canal

    Directory of Open Access Journals (Sweden)

    Edwin Hurtado Orobio

    2009-01-01

    Full Text Available Se estudió si las aristas traseras de las juntas longitudinales de una losa de piso, fija al fondo de un canal con flujo supercrítico, convierten energía cinética en energía de presión en el rango de números de Froude de 2,84 a 10,12. En cada prueba, se midió la presión en 16 puntos de su cara inferior, con transductores piezoresistivos en tres líneas longitudinales: una central con 8 sensores y dos laterales, a lado y lado de la primera, con cuatro sensores cada una. De esta forma, se determinó la distribución de las presiones medias debajo de la losa ensayada, similar a las usadas en obras civiles para evitar la acción erosiva de la turbulencia de un flujo supercrítico. El análisis de las presiones medidas muestra que, aún cuando las caras superiores del piso del canal y del bloque protector estén en el mismo plano horizontal, las aristas traseras de las juntas longitudinales transforman energía de velocidad en energía de presión. Así, se ha detectado un factor que interviene en la generación de la fuerza hidrodinámica que levanta revestimientos de diverso tipos de estructuras, hasta ahora ignorado en el estudio de este problema.

  9. Simulador de manejo forestal de la Selva Pedemontana de Yungas

    OpenAIRE

    Humano, C.; León Ruíz, S.; Solís, J.

    2016-01-01

    El objetivo de este trabajo fue desarrollar un software que permita simular la evolución, en un periodo de 25 años, de un rodal nativo sujeto a distintos sistemas de manejo forestal. Este simulador se generó con una base de datos obtenidas de 8 parcelas de medición permanentes de árboles de un tamaño de 1ha, medidas en dos instancias en el año 2003 y 2008. El total de individuos remedidos fue de 4750, en cada uno ellos se determinaron los datos de especie, diámetro altura al pecho (Dap), altu...

  10. Conocimientos previos acerca de métodos anticonceptivos y su relación con conocimientos adquiridos después de una intervención educativa con simulador

    Directory of Open Access Journals (Sweden)

    María Neyfeth Posada Morales

    2015-01-01

    Full Text Available Introducción. El objetivo de este trabajo es relacionar conocimientos previos (pre-saberes acerca de métodos anticonceptivos con los conocimientos adquiridos (saberes, después una intervención educativa con simulador.Método. Es un estudio realizado con 295 adolescentes escolarizados que cursan noveno, décimo y undécimo en una institución educativa pública. Es de tipo descriptivo. El proceso estuvo compuesto por tres fases; en la primera se midió conocimientos o saberes previos acerca de métodos anticonceptivos, mediante un cuestionario auto-informado; en la segunda se definió los contenidos y actividades de intervención para mejorar los conocimientos previos, y en la tercera fase de post-intervención educativa, se reevaluó los saberes adquiridos con el simulador. Resultados. Se detectó que los pre-saberes en métodos anticonceptivos son deficientes independientemente de la edad y la escolaridad, lo cual requiere planeación, desarrollo y evaluación de la estrategia de aprendizaje colectivo y cooperativo mediante talleres. En cuanto a los post-saberes, se obtuvo una calificación de deficientes a regulares, en el caso del condón masculino, mientras que el reconocimiento de métodos modernos como parche, anillo vaginal, dispositivo intrauterino, entre otros, se dio gracias al contacto directo con el simulador.Conclusiones. Se recalca que a pesar de las  diferencias de edad y escolaridad, no hubo hallazgos relevantes que demostraran diferencias de conocimiento. En los pre-saberes, se encontró niveles de conocimiento deficientes sobre métodos anticonceptivos. El uso de simuladores como herramienta de aprendizaje demostró eficacia en los talleres; en cuanto a los simuladores posibilitan la ruptura de la barrera cognitiva, dado que el adolescente, en este caso, puede explorar y adquirir conocimiento al interaccionar con el objeto de aprendizaje.

  11. Simulador de radar meteorológico basado en modelo de Reflectividades en el espacio; Weather radar simulator based on space Reflectivity distribution

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    Vladímir Rodríguez Diez

    2012-07-01

    Full Text Available Los radares meteorológicos son potentes instrumentos de medición de potencia eléctrica. Los simuladores de radar permiten estudiar la influencia de todos sus parámetros en las mediciones que realiza. Su aplicación en laactualidad comprende el estudio de la influencia de las propiedades físicas de los hidrometeoros y la configuración del radar en la observación; y el estudio del desempeño de los modelos climáticos a partir de la confrontación de lasalida del simulador con la observación real. En este trabajo se utiliza como entrada al simulador una distribución de Reflectividades (parámetro proporcional a la potencia retornada en la atmósfera; obviando la compleja relación que existe entre esta última y las propiedades físicas del blanco meteorológico. El resultado es un simulador que posibilita el estudio de los efectos de patrón de escaneo de la atmósfera y el esquema de adquisición yprocesamientos de los datos, sobre la percepción de un blanco meteorológico. Weather radar are powerful measurement instruments for electric power. Radar simulators allows to investigate the influence of its parameter on measurements.Its application comprehend the study of influence of hydrometeor's physical properties and radar configurations in observation; and the study of climate model performance upon the confrontation of simulator output versus actual observations. In this work simulator input is given as a spacial reflectivity (proportional to returned power distribution in atmosphere, obviating the complex relation between this and physical properties of meteorological target. The result is a simulator for the study of volume scan pattern and acquisition and processing scheme effects on weather target observation.

  12. Enseñanza de técnicas quirúrgicas básicas en simuladores biológicos: Experiencia pedagógica en el pregrado

    Directory of Open Access Journals (Sweden)

    Ricardo Alberto Torres

    Full Text Available Introducción: las maniobras quirúrgicas básicas que un médico generalista debería aprender en el cursado de la Carrera de Medicina, implican la adquisición de destrezas y habilidades manuales de tipo cruentas. Estos procedimientos, por su carácter de invasivos, representan una dificultad en el proceso de enseñanza-aprendizaje tradicional realizada sobre el paciente. Se propone una alternativa pedagógica para la adquisición de habilidades quirúrgicas básicas en simuladores biológicos en el pregrado. Material y Métodos: durante el año 2002 se desarrollaron en la Facultad de Medicina de la Universidad Nacional del Nordeste dos cursos teórico-prácticos de Técnicas Quirúrgicas Básicas destinados a alumnos de los dos últimos años de la carrera. Los simuladores fueron trozos de carne, intestino delgado, corazón y pulmón de vaca, alas de pollo, cerdos vivos y cadáveres de los mismos. Los alumnos practicaron diferentes procedimientos quirúrgicos guiados por un tutor. La práctica estuvo precedida por una clase teórica de la técnica, aplicada al paciente. Las condiciones para aprobar el curso fueron: asistir al 80% de las jornadas y un examen final práctico sobre simuladores, de las destrezas adquiridas. Al finalizar debieron contestar una encuesta. Resultados: el cupo de 50 alumnos por curso fue cubierto completamente. El 100% de los alumnos aprobó el examen final práctico. La encuesta catalogó la modalidad pedagógica como excelente en un 96% y muy buena en el 4%. Conclusiones: en la búsqueda de una solución pedagógica de cómo adquirir habilidades y destrezas en maniobras quirúrgicas básicas, esta metodología resultó ser una excelente alternativa en el pregrado.

  13. Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle Cardenas, B.; Lugo Leyte, R. [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G. [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

    1998-12-31

    This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

  14. Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle Cardenas, B; Lugo Leyte, R [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

    1999-12-31

    This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

  15. Training simulators for power plant operation based in multimedia, intelligent tutorials and virtual reality; Simuladores para entrenamiento en la operacion de centrales basados en multimedia, tutores inteligentes y realidad virtual

    Energy Technology Data Exchange (ETDEWEB)

    Rossano Roman, Miguel; Tavira Mondragon, Jose A.; Romero Jimenez, Guillermo; Buenabad Arias, Maria de los Angeles [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The possibility of utilizing simulators to support the fossil fuel power plants operation personnel training, is analyzed. These simulators can be based in multimedia, intelligent tutorials and virtual reality. The software and hardware advances of these technologies are analyzed and it is concluded that the simulators development for operators training supported in the fore mentioned technologies represents a new alternative for the instruction of personnel of this type of power stations that has to be analyzed and evaluated, since one of the disadvantages of this type of technologies is the equipment and software investment cost [Espanol] Se analiza la posibilidad de utilizar simuladores para ayudar al entrenamiento del personal en la operacion de centrales termoelectricas, dichos simuladores pueden estar basados en multimedia, tutores inteligentes y realidad virtual. Se describen los avances en software y hardware de estas tecnologias y se concluye en que el desarrollo de simuladores para el entrenamiento de operadores apoyados con las tecnologias antes mencionadas representa una nueva alternativa para la instruccion del personal de este tipo de centrales, que hay que analizar y evaluar, ya que una de las desventajas de este tipo de tecnologias es el costo de inversion en equipo y software

  16. Training simulators for power plant operation based in multimedia, intelligent tutorials and virtual reality; Simuladores para entrenamiento en la operacion de centrales basados en multimedia, tutores inteligentes y realidad virtual

    Energy Technology Data Exchange (ETDEWEB)

    Rossano Roman, Miguel; Tavira Mondragon, Jose A; Romero Jimenez, Guillermo; Buenabad Arias, Maria de los Angeles [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The possibility of utilizing simulators to support the fossil fuel power plants operation personnel training, is analyzed. These simulators can be based in multimedia, intelligent tutorials and virtual reality. The software and hardware advances of these technologies are analyzed and it is concluded that the simulators development for operators training supported in the fore mentioned technologies represents a new alternative for the instruction of personnel of this type of power stations that has to be analyzed and evaluated, since one of the disadvantages of this type of technologies is the equipment and software investment cost [Espanol] Se analiza la posibilidad de utilizar simuladores para ayudar al entrenamiento del personal en la operacion de centrales termoelectricas, dichos simuladores pueden estar basados en multimedia, tutores inteligentes y realidad virtual. Se describen los avances en software y hardware de estas tecnologias y se concluye en que el desarrollo de simuladores para el entrenamiento de operadores apoyados con las tecnologias antes mencionadas representa una nueva alternativa para la instruccion del personal de este tipo de centrales, que hay que analizar y evaluar, ya que una de las desventajas de este tipo de tecnologias es el costo de inversion en equipo y software

  17. Um estudo da simulação de serviços da Amazon ec2 utilizando o simulador Cloudsim

    OpenAIRE

    Crespo Guzmán, Alberto

    2011-01-01

    English: In the first part of the project, is made a theoric study of Cloud Computing's technology and Amazon's company. After this, it has a introduction about the simulador CloudSim. The second part is devoted to the adaptation of CloudSim with the Amazon's Company, the extration of estadistics and theirs conclusions Castellano: En la primera parte del proyecto se hace un estudio teórico de la tecnología de la Computación en Nube y de la empresa Amazon. Es seguido por una introducción al...

  18. ANALSIS DEL PATRÓN Y LAS PRESIONES PLANTARES DURANTE LA RECEPCIÓN EN UNA COLCHONETA

    Directory of Open Access Journals (Sweden)

    F. Huertas

    2010-10-01

    Full Text Available
    Dentro de las rutinas de la gimnasia deportiva, un elemento común son las
    recepciones sobre la colchoneta. En este sentido, diversos han sido los estudios cinéticos y cinemáticos realizados sobre la recepción y cuyos resultados pueden han sido útiles para la mejora en la compresión de la recepción y diseño de colchonetas. No obstante, el estudio de las presiones plantares durante la recepción no ha sido desarrollado por ninguna
    investigación a pesar de que el pie transmite al cuerpo las cargas de reacción generadas en el contacto con la colchoneta y dependiendo de su magnitud, frecuencia y punto de aplicación se pueden producir diferentes lesiones. El conocimiento de dichas cargas es importante no solo para la prevención de lesiones o criterios en el diseño de colchonetas, sino también para la mejora del rendimiento deportivo, mejorando la estabilidad durante la recepción. El presente trabajo muestra cuales son las zonas del pie a analizar, el patrón y las magnitudes de las presiones plantares durante una recepción tras un salto.

  19. Simulador de chuva tipo empuxo com braços movidos hidraulicamente: fabricação e calibração

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2012-12-01

    Full Text Available O uso de simuladores de chuva é fundamental em estudos de erosão hídrica pluvial. Com eles é possível controlar as condições experimentais, principalmente as características da chuva, e compreender melhor o processo erosivo do solo. Vários tipos de simulador de chuva foram desenvolvidos desde 1930 no mundo. Atualmente, o tipo Swanson é o mais utilizado. No entanto, um pequeno número desses simuladores está em pleno funcionamento no Brasil, devido ao alto grau de desgaste e às dificuldades de manutenção. O objetivo deste trabalho foi desenvolver um novo modelo de simulador de chuva, construído predominantemente em alumínio, desprovido de motor para rotação dos braços e movido hidraulicamente por empuxo. O simulador de chuva movido hidraulicamente por empuxo mantém em geral as características do modelo Swanson, sobretudo aquelas relacionadas às características de chuva produzida, tendo sido minimizados seu excesso de peso e a necessidade de uso de um motor a gasolina para movimento dos braços, denominado "Tipo Empuxo". Essas características tornaram o novo modelo mais leve, econômico, silencioso e de fácil manejo na área experimental do que o modelo Swanson, sendo possível deslocá-lo com apenas quatro pessoas. A intensidade da chuva correlacionou-se linear e positivamente com a pressão da água no manômetro.

  20. Os Usos de Simuladores Durante a Formação Profissional para a Condução de Transportes Rodoviários

    Directory of Open Access Journals (Sweden)

    Thiago Drumond Moraes

    Full Text Available Resumo Este estudo teórico pretende contribuir com o debate sobre o uso de simuladores nos processos de formação para os profissionais de transporte terrestre rodoviário. Nesse tipo de transporte no Brasil ocorrem muitos acidentes, configurando-se em um problema de saúde pública. Procurou-se analisar criticamente, a partir da produção acadêmica sobre uso de simuladores, suas potencialidades em situações de formação para condutores profissionais. A partir de uma perspectiva ergológica, que permite a articulação com outras clínicas do trabalho, também utilizadas, o artigo tem como objetivos: discutir as características que conformam a atividade de condução, fazer uma análise dos pressupostos epistemológicos subjacentes às pesquisas e treinamentos que usam simuladores e articular criticamente tais pontos para avaliar a pertinência do uso de simuladores em processos de formação profissional. Evidenciou-se que os processos de formação profissional mediado pelo uso de simuladores podem ser pertinentes para a grave situação do trânsito brasileiro, embora se reconheça ausência de pesquisas nacionais sobre a temática, bem como alguns possíveis limites da perspectiva epistemológica utilizadas nas pesquisas internacionais, afetando a eficácia deste uso.

  1. El simulador en línea como herramienta de formación para personas con pérdida auditiva

    OpenAIRE

    Quintana, Nelba; González, Alejandro Héctor; Madoz, María Cristina

    2017-01-01

    Este trabajo consiste en la presentación de la mejora de un simulador educativo en línea, para aprender el uso de herramientas digitales como medio para optimizar sus estrategias comunicacionales en una entrevista laboral; dicho simulador se denominará ELH (entrevistas laborales para personas con hipoacusia) y será utilizado en un curso de capacitación a personas con pérdida auditiva que utilizan dispositivos auditivos (audífonos o implantes cocleares). Se basa en el trabajo final presentado ...

  2. Desenvolvimento de um simulador com interface amigável de um módulo didático de transferência de calor em aletas

    Directory of Open Access Journals (Sweden)

    Welington Pereira Santos

    2001-05-01

    Full Text Available Neste trabalho, foi implementado um simulador com interface amigável de um módulo didático clássico de transferência de calor em aletas, utilizado em várias instituições de ensino superior. O simulador foi desenvolvido em linguagem orientada a objetos DELPHI e apresenta um formulário de entrada de dados interativo em uma janela, enquanto o resultado da simulação é visualizado na forma gráfica. O simulador possui um banco de correlações de literatura para a estimação das propriedades físicas e dos parâmetros térmicos do modelo

  3. Inactivación de microorganismos por altas presiones en la industria vinícola

    Directory of Open Access Journals (Sweden)

    Jaime Nelson Montaña B.

    2000-01-01

    Full Text Available Con el fin de evaluar experimentalmente la capacidad de los gases C02 y N2 bajo presión para inactivar levaduras salvajes, mostos de uva del Viñedo y Cava de Puntalarga (Nobsa, Boyacá, estos se sometieron a tratamientos hiperbáricos con los mencionados gases. El C02 a 15°C y presiones entre 1 y 5 MPa alcanzó altos porcentajes de inactivación de células de levadura (>90% al final del proceso de pascalización (después de 2 horas. Contrario al tratamiento con C02, el uso de N2 a 15°C falló para ejercer un efecto microbicida a 4 y 10 MPa durante un tiempo igual de proceso. Mientras el C02 de alta solubilidad en H20 tiene el potencial para reducir cargas microbianas en mostos; el N2de baja solubilidad en H20, no tiene efecto significativo sobre la supervivencia de microorganismos patógenos en dicho jugo.

  4. PROSPECÇÃO EM SIMULADOR DE ENERGIA ELÉTRICA

    OpenAIRE

    Ribeiro, Elisalvo Alves; Universidade Federal de Sergipe; Nunes, Maria Augusta Silveira Netto; Universidade Federal de Sergipe

    2014-01-01

    O processo de educar a população, em relação ao hábito de consumo consciente, é uma árdua tarefa, visto que as pessoas vivem em torno de aparatos tecnológicos que evoluem com uma velocidade nunca antes vivida pela humanidade, os quais oferecem mais comodidade, porém, em contrapartida incita-se a consumir mais energia. Assim, um dos meios de auxiliar as pessoas a terem um consumo consciente, é possibilitando-lhes mensurar seus consumos diários, através de um simulador de consumo, onde este pos...

  5. Simulador y diseñador de redes informáticas

    OpenAIRE

    Salmerón Díaz, Juan Transito

    2008-01-01

    El proyecto desarrollo de un diseñador y simulador de redes informáticas, para su implementación como herramienta didáctica en la materia de redes informáticas, tuvo sus inicios por la necesidad de dotar a los docentes de la Regional San Miguel, de una herramienta didáctica adicional, para simular pruebas sobre aspectos básicos de networking y a los alumnos, permitir desarrollar análisis de estructuras y costeos de redes, sin necesidad de implementar una red físicamente.

  6. Experimentación virtual con el simulador dosis-respuesta como herramienta docente en biología

    Directory of Open Access Journals (Sweden)

    Arturo Reyes Lazalde

    2016-10-01

    Full Text Available Presentamos una estrategia de innovación educativa consistente en la implementación de un proyecto de investigación virtual en biología. En la educación universitaria presencial, algunas prácticas de laboratorio son prohibitivas por sus altos costos. En la educación a distancia existen pocos materiales virtuales que las sustituyan. En este trabajo compartimos la experiencia del uso del simulador dosis-respuesta 1.0 desarrollado en nuestro laboratorio con el objetivo de explorar su usabilidad y niveles de aprendizajes alcanzados. La investigación fue exploratoria con un grupo de alumnos del curso Métodos de investigación I de la carrera de Biología. El trabajo corresponde a una investigación virtual, estructurada, de tipo semicerrado y guiada por supervisión docente especializada, y evaluó dos niveles de conocimiento: el manejo del programa y la comprensión de los conocimientos teóricos. El 69.2% de los alumnos indicaron que el uso del simulador fue fácil. De acuerdo con la taxonomía de Bloom, de 100 a 92.3% realizaron bien actividades en los niveles aplicar y analizar, y de 76.9 a 61.5, en el nivel sintetizar; 7.7% no se adaptaron. Los resultados señalan que los alumnos alcanzan altos niveles de aprendizaje. Los simuladores son una alternativa para la enseñanza cuando las prácticas de laboratorio son costosas.

  7. Variáveis microeconômicas em simuladores para jogos de empresas: um estudo comparativo Microeconomic variables in business games: a comparative study

    Directory of Open Access Journals (Sweden)

    André Rosenfeld Rosas

    2006-09-01

    Full Text Available Esta pesquisa visa categorizar as variáveis microeconômicas presentes em cinco simuladores brasileiros para Jogos de Empresas, com o intuito de identificar de que forma tais simuladores podem preparar os gestores para atuar em diferentes cenários econômicos. Foi realizada análise descritiva dos manuais dos participantes, em busca das seguintes categorias de variáveis microeconômicas: exame das estruturas de mercado, previsão da demanda, análise da oferta e análise de custos econômicos. Encontrou-se um total de 35 variáveis microeconômicas, categorizadas em distintos graus de importância nos modelos. Constatou-se que tais simuladores permitem aos estudantes gerenciar todas as categorias de variáveis estudadas. Também foi possível verificar que os simuladores se diferenciam, principalmente, quanto a: estruturas de mercado, análise de oferta e previsão de demanda. Caberá ao facilitador identificar, por meio dessas categorias, o simulador mais adequado ao objetivo da disciplina e ao perfil da turma. Duas contribuições destacam-se: 1 o esforço de ampliar a utilização de Jogos de Empresas para a prática de conceitos de Microeconomia, incentivando a interdisciplinaridade; e 2 a proposição de uma estrutura comparativa de simuladores para apoiar a escolha do facilitador.Microeconomic variables found in five Brazilian business games were grouped into categories in order to identify the way in which these games provide managerial experience for different economic scenarios. A descriptive analysis of players' manuals searched for microeconomic variables in the four categories of examination of market models, demand forecast, supply analysis and economic cost analysis. A total of 35 microeconomic variables were found and grouped into categories of graduated importance in the models. All the games allowed students to manage all the categories of variables studied and they differed, mainly with regard to the categories of aspects of

  8. ADAPTABILIDAD DE LAS FAMILIAS AGRÍCOLAS ANTE PRESIONES ECONÓMICAS Y ECOLÓGICAS: UN CASO DE CAFÉ DE ALTURA EN LEÓN CORTÉS, COSTA RICA

    OpenAIRE

    Valenciano Salazar, Jorge Andrey

    2012-01-01

    Resumen Los medios de vida de las familias productoras de café de altura están ligados a la finca. Esta relación tan marcada (familia – finca) los hace vulnerables a presiones externas que alteran el funcionamiento cotidiano interno de la unidad productiva. Dentro de estas presiones externas se encuentran los bajos precios, efectos climáticos y plagas en el cafetal. El artículo busca identificar los impactos que ejercen dichas presiones sobre los medios de vida de las familias cafetaleras ...

  9. SIMULINVE – Um simulador de inventário para um centro de distribuição de peças

    Directory of Open Access Journals (Sweden)

    Heráclito Lopes Jaguaribe Pontes

    2008-10-01

    Full Text Available No mercado globalizado atual, as empresas buscam garantir disponibilidade de produto ao cliente final, com o menor nível de inventário possível. As ferramentas de simulação disponibilizam aos gestores melhores visões do negócio e melhores condições para a tomada de decisão. Em um Centro de Distribuição de Peças (CDP, para se alcançar um melhor desempenho no gerenciamento do inventário é importante poder contar com uma ferramenta capacitada para realizações de simulações de possíveis cenários. Este trabalho teve como objetivo desenvolver um processo para gerenciamento de inventario que resultou em um simulador de inventário para CDP. O simulador realiza projeções visando obter como resultados a previsão de demanda, a política de reposição das peças, o percentual de atendimento dos pedidos, os meses de inventário, a quantidade de Scrap e a quantidade de peças. O simulador foi submetido a experimentos com três cenários diferentes e os resultados confirmaram a qualidade do sistema de simulação proposto.

  10. Desarrollo de un simulador de bajo costo para la adquisición de destrezas básicas en cirugía artroscópica. [Development of a low-cost simulator to acquire basic arthroscopic skills.

    Directory of Open Access Journals (Sweden)

    Gabriel O. Alonso Cuéllar

    2014-06-01

    Full Text Available In­tro­duc­ción: El propósito del estudio fue desarrollar, bajo parámetros de expertos y evaluación de idoneidad por el usuario final, un simulador mecánico de bajo costo, que permita desarrollar destrezas básicas, pero fundamentales, en el aprendizaje de la artroscopia. Materiales ­y ­Métodos: El trabajo se dividió en tres fases; en la primera, se encuestaron expertos y se establecieron criterios para el desarrollo del simulador artroscópico. Luego, se desarrolló el prototipo del simulador usando, además de los criterios mencionados, las características del instrumental y los objetivos de cada ejercicio planteado. Por último, se llevaron a cabo pruebas, usando el simulador final, con ortopedistas que realizaron el entrenamiento. Resultados: Se obtuvieron algunos criterios de importancia para el desarrollo del simulador, que se emplearon en el desarrollo del modelo final, cuyo costo estuvo por debajo de los 300 dólares estadounidenses. En cuanto a la aplicación práctica, se obtuvo una satisfacción del 100% y una idoneidad del 97,4% por parte de los ortopedistas que realizaron el entrenamiento. Conclusiones: Desarrollar procesos de entrenamiento es una labor fundamental de los centros de aprendizaje quirúrgico. El simulador ArtroCLEMI II probó ser una herramienta útil en el desarrollo de destrezas básicas de artroscopia, con costos mínimos y alta versatilidad. Es necesario fortalecer los procesos curriculares aplicados a las curvas de aprendizaje quirúrgico.

  11. A Rainfall Simulator for the in situ Study of Superficial Runoff and Soil Erosion Un simulador de lluvia para el estudio in situ de la escorrentía superficial y la erosión de suelos

    Directory of Open Access Journals (Sweden)

    Claudia Sangüesa

    2010-03-01

    diferentes pendientes, donde se cuantificó la escorrentía superficial y la erosión del suelo. En total se realizaron 20 simulaciones en laboratorio y 16 en terreno con pendientes de 11, 21 y 39%. Los cuatro aspersores en línea generaron una lluvia con una uniformidad cercana al 90%. El simulador construido fue una herramienta de fácil uso y bajo costo, que facilitó la realización de las repeticiones experimentales necesarias para lograr una adecuada representatividad espacial de la escorrentía superficial y pérdida de suelo en laderas.

  12. Método estadístico factorial a dos niveles aplicado en los experimentos de explotación de los Simuladores. // Two levels factorial statistical method applied in experiments of Simulators operation.

    OpenAIRE

    P. Moreno Quintana; J. Villar Cociña

    2002-01-01

    La introducción de los simuladores en el proceso de instrucción en el país cuenta con una dificultad al no conocerse el realimpacto de este tipo de equipamiento en la adquisición de las habilidades dentro del proceso de entrenamiento a que vadirigido.El empleo del método estadístico factorial a dos niveles permite la obtención de un modelo lineal de respuesta de laeficiencia, o calificación, en función de la forma cuantitativa de empleo de los diversos medios de entrenamiento y suscombinacion...

  13. Aten-pre. Simulador de atención prenatal A simulator of prenatal care

    Directory of Open Access Journals (Sweden)

    Hipólito Breijo Madera

    2007-06-01

    Full Text Available Se realizó una investigación del tipo innovación tecnológica en el Policlínico Universitario Pedro Borrás Astorga de Pinar del Río, de septiembre de 2005 a junio del 2006, decidiéndose confeccionar un software para mostrar rápidamente los principales parámetros de la consulta de Atención Prenatal, según el tiempo de gestación de la embarazada. El universo estuvo constituido por todos los estudiantes de Ciencias Médicas que asistieron en este período a la Biblioteca del Policlínico mencionado. La muestra fueron aquellos estudiantes (214 que utilizaron el simulador por algún motivo y decidieron voluntariamente responder la encuesta aplicada. En la realización de este medio se utilizó una microcomputadora Celerón a 600Mhz con el sistema operativo Windows XP y el Software Macro media Flash 5, utilizando el español como lenguaje y creando un simulador de consultas de Atención Prenatal (ATENPRE con secuencias multimedia, que a través de una serie de enlaces llevan al usuario a reconocer la consulta buscada. Dentro de los principales resultados se encuentra más de 90% de aceptabilidad, eficiencia y utilidad, llegando a la conclusión de que el software educativo (ATEN-PRE es una herramienta más a utilizar por los estudiantes de pregrado en la búsqueda activa de información.A research on technological innovation at "Pedro Borrás Astorga" Outpatient Clinic in Pinar del Río was carried out from September 2005 to July 2006, where a software to show the main parameters in the consult of Prenatal Care considering time of pregnancy was created. The sample was constituted by all the medical students attending the library of the outpatient clinic during the period mentioned. In the final sample, 214 students using the simulator by any reasons decided voluntarily to answer the survey applied .To create this teaching aid a Celeron (600Mhz microcomputer with Windows XP operative system and the Software Flash 5 Macromedia (in Spanish

  14. Control Desacoplado de Plataforma Neumática de 3-GDL utilizada como Simulador de Movimiento

    Directory of Open Access Journals (Sweden)

    Eduardo Izaguirre

    2011-10-01

    Full Text Available Resumen: En el presente artículo se realiza el análisis cinemático y esquema de control articular desacoplado para un robot paralelo de tres grados de libertad, accionado por actuadores neumáticos, que se emplea como simulador de movimiento. Luego de efectuar una breve descripción del robot, se obtiene el sistema de ecuaciones que describe el comportamiento cinemático inverso del mismo, empleándose la formulación vectorial. Las relaciones cinemáticas analíticas son debidamente validadas mediante simulación conjunta entre el Matlab y el paquete de software Adams. Se propone un esquema de control desacoplado para cada articulación, donde mediante la cinemática inversa se calculan los valores deseados de las variables articulares. Los lazos de control se implementan en un robot paralelo de tres grados de libertad en una aplicación de control de posición. Finalmente se muestran los resultados experimentales obtenidos que demuestran la efectividad del esquema de control cinemático articular en términos de desempeño del sistema. Palabras clave: Control desacoplado, Cinemática inversa, Simulador de movimiento, Robot paralelo

  15. Validación del modelo expo-lineal precipitación-escurrimiento en un simulador de lluvia

    Directory of Open Access Journals (Sweden)

    Fernando Paz

    2017-10-01

    Full Text Available La necesidad de desarrollar métodos simplificados, operativos y coherentes para modelar la relación precipitación-escurrimiento a escala de eventos, permanece como uno de los grandes retos en el campo de la hidrología. Si bien existen propuestas simples de modelación como el método del Número de Curva o NC, sus bases teóricas no tienen fundamentos hidrológicos. La ventaja del método del NC es que solo requiere de un parámetro, lo cual lo hace muy atractivo en las aplicaciones. En este trabajo se analizan las bases del método del NC. Los resultados muestran que estos intentos simplificados de modelación están limitados. Por otro lado, el modelo expo-lineal de Paz (2013 es flexible en términos empíricos. Las bases teóricas de este modelo son discutidas en términos de la hidrología de área variable, en un formato suficientemente general para hacer solido su uso. El modelo se aplicó a un experimento en un simulador de lluvias con lotes de escurrimiento con diferentes tipos de suelo y coberturas aéreas de pastos. Los resultados mostraron un buen ajuste experimental a los datos, particularmente en términos de parametrizar el modelo expo-lineal en forma similar al método del NC. De estos desarrollos, se presenta un esquema de estimación de los parámetros del modelo expo-lineal que se puede usar en forma equivalente, por su simplicidad al tener un solo parámetro libre, al método del NC.

  16. Una experiencia docente en el empleo de los simuladores gráficos en el desarrollo de prácticas de laboratorios de Sistemas Integrados de Manufactura. // An educational experience with graphical simulators in course of Computer Integrated Manufacturing.

    Directory of Open Access Journals (Sweden)

    G. González Rey

    2004-05-01

    Full Text Available En el trabajo se presentan algunos ejemplos de simuladores gráficos con empleo en el desarrollo de las practicas de laboratoriode Sistemas Integrados de Manufactura, a partir de experiencia de los autores en una Celda de Manufactura con integración demáquinas de control numérico, robots manipuladores y ensambladores, líneas flexibles de transportación, sistemas deinspección y un software de simulador de procesos.Palabras claves: Sistema Integrado de Manufactura, SIM, CIM, simuladores gráficos, AMNET, MasterCAM,inspección por visión.______________________________________________________________________________Abstract .In the work some examples of graphical simulators are presented as important tools in the development of an educationalactivity in a Cell of Manufacturing during a course of Computer Integrated Manufacturing. In this experience, was developedan integration of CNC machines, robots, conveyor flexible lines, inspection systems and software for direction of allprocesses.Key words: Computer Integrated Manufacturing, CIM, CAD, graphical simulators, AMNET, MasterCAM, visualinspection.

  17. Incorporation of the pressure control system to the classroom simulator; Incorporacion del sistema de control de presion al simulador de aula

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez J, J. [UNAM, Laboratorio de Analisis de Ingenieria de Reactores Nucleares, DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: shaqaul@hotmail.com

    2004-07-01

    In the nucleo electric centrals, the information systems, support for the decisions making and training are every day more complex and important. The present work is a contribution in this sense, specifically, it is part of a tool of training and analysis developed by the Laboratory of Analysis in Engineering of Nuclear Reactors (LAIRN) of the Faculty of Engineering of the UNAM that consists essentially of a simulator of the Laguna Verde Nucleo electric plant; the classroom simulator, understands the physical systems that compose to the power station and graphic interfaces for its operation and the analysis of results. The project of the classroom simulator is carried out in independent modules that are integrated to the total system as these they are developed and proven. The central objective of this work consists on the development, implementation and it proves of a model of the pressure control system according to the characteristics of the Nucleo electric plant of Laguna Verde, as well as the development of the mimic ones and unfolding necessary graphics to make its interactive operation from sensitive monitors to the tact. The pattern of the control system was developed using as tool the nuclear code of simulation RELAP/SCDAP, designed for the analysis of the types of nuclear reactors more common in occident, and it allows the typical maneuvers in the ways of start up, heating and operation to power, showing an appropriate behavior during the more common operational transitoriness. (Author)

  18. Simulador interativo de estabilidade de usinas termelÃtricas de ciclo combinado para projetos, pesquisa e treinamento

    OpenAIRE

    Gabriel Josà Alves dos Santos

    2012-01-01

    Neste trabalho foi desenvolvido o estudo e as aplicaÃÃes das condiÃÃes de estabilidade na operaÃÃo do sistema elÃtrico de potÃncia incorporado em um simulador interativo de usinas termelÃtricas de ciclo combinado, que permita melhorar os processos de treinamento e, consequentemente, o nÃvel de qualidade dos futuros operadores e mantenedores de usinas termelÃtricas, bem como manter atualizados os atuais operadores. Um pequeno conjunto de definiÃÃes e conceitos das Ãreas de âestabilidade, confi...

  19. Análisis comparativo de la aplicación de protocolos de evaluación de conductores con discapacidades severas que conducen con Joysticks de 4 vías entre los simuladores de conducción SERCO y UPV-DGT

    OpenAIRE

    ALAGARDA CONTRERAS, RAIMON

    2016-01-01

    [ES] El presente TFG tiene por objeto el análisis inter-comparativo entre los procedimientos de evaluación de conductores con discapacidades severas que conducen con la ayuda de adaptaciones del tipo Joystick de 4 vías, y que se implementan en los simuladores de conducción SERCO y UPV-DGT. Ambos simuladores se encuentran ubicados actualmente en las instalaciones del Instituto de Diseño y Fabricación (IDF). Se ha estudiado el comportamiento de diferentes tipos de conductores (co...

  20. Thermodynamic performance of gas turbine; Comportamiento termodinamico de las turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Lugo Leyte, Raul [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico); Velazquez Toledo, Miguel; Hernandez Fernandez, Angel [Escuela Superior de Ingenieria Mecananica y Electrica, Academia Mecanica, Instituto Politecnico Nacional, Mexico D.F. (Mexico); Torres Aldaco, Alejandro [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico)

    2003-01-15

    This work presents a computer code developed to simulate thermodynamic performance of a gas turbine cycle. The predicted performance is determined by measurements, in terms of various thermodynamics performance parameters which are defined and discussed in this paper. These parameters include the output, efficiency, fuel flow rate and air flow rate in relation to variations in the ambient temperature, pressure ratio, turbine entry temperature, compressor isentropic efficiency and turbine isentropic efficiency. [Spanish] Se presenta el comportamiento termodinamico de las centrales termicas que operan con turbinas de gas al variar los siguientes parametros: condiciones ambientales, relacion de presiones, temperatura de los gases a la entrada de la turbina de gas y las eficiencias isentropicas de compresion y expansion. Los resultados obtenidos son la eficiencia termica, el trabajo motor generado, el exceso de aire y los flujos de combustible en funcion de los parametros citados anteriormente. El analisis parametrico se realizo con el simulador TURBOGAS disenado en el laboratorio de ingenieria termica e hidraulica aplicada de la seccion de estudios de posgrado e investigacion de la escuela superior de Ingenieria Mecanica y Electrica del Instituto Politecnico Nacional.

  1. Validation of Hiriart equation to compute steam production by the lip pressure method; Validacion de la ecuacion de Hiriart para calculo de gasto de vapor por el metodo de presion de labio

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-09-01

    Mainly in new geothermal wells, it is necessary to evaluate the production in a very fast, simple and not expensive way, to know the convenience to install surface equipment, such as silencers and separators, to drive the steam to the commercial gathering system. In practice, one of the most known methods is the lip pressure one, which requires a simple set of installations. The objective of this paper is to validate the steam flow rate calculated by the lip pressure method, with respect to the ASME method. The ASME method is known for its accuracy, and is done by measuring the steam and liquid after a high pressure separator, by an orifice plate of known diameter and a triangular weir. Results of the validation show up the feasibility of application of the lip pressure method by using a simple adjustment equation. Percentage of mistake results less than 1%, without any notable influence of the production enthalpy. That equation to be applied in a general case, is as follows: Q{nu} =(20642)(F*P*D{sup 2}/{radical}h-2000). For the particular case of the Los Azufres geothermal field, the equation is: Q{nu}= 810*P*D{sup 2} [Espanol] En los pozos geotermicos, principalmente en los nuevos, es necesario evaluar su produccion de manera rapida, sencilla y economica, para determinar la conveniencia de instalar equipo superficial, como separadores, silenciadores, etc., que permita la integracion del vapor al sistema comercial de generacion electrica. Para fines practicos uno de los metodos mas conocidos es el de presion de labio, que solo requiere un arreglo sencillo de instalaciones superficiales. En este documento se validan y ajustan los calculos de produccion de vapor por ese metodo de presion de labio, con respecto a las mediciones exactas efectuadas con el metodo ASME. Este ultimo es reconocido internacionalmente por su precision, y se lleva a cabo separando la mezcla obtenida en superficie en un recipiente a presion para medir el vapor a traves de una placa de orificio

  2. Modeling automation of hydraulic networks with application in training simulators; Automatizacion del modelado de redes hidraulicas con aplicacion en simuladores para entrenamiento

    Energy Technology Data Exchange (ETDEWEB)

    Roldan, Edgardo; Tavira, Jose [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The modeling of hydraulic networks is a fundamental task in the development of simulators for operator`s training. Having an automatic tool that eases the implementation of this models in a simulator, without the need that the user has to formulate and program his specific problem, represents a great saving of time and effort. In this paper the generalities of a computer program that allows the characterization and testing of models of hydraulic networks, are presented. A graphical interface is described; the principles on which the six types of models that the user can choose, are summarized and the results obtained, are presented. [Espanol] El modelado de redes hidraulicas es una tarea primordial dentro del desarrollo de simuladores para el entrenamiento de operadores. El contar con una herramienta automatica que facilite la implantacion de estos modelos en un simulador, sin que el usuario tenga que formular y programar su problema especifico, representa un gran ahorro en tiempo y esfuerzo. En este articulo se presentan las generalidades de un programa computacional que permite caracterizar y probar modelos de redes hidraulicas. Se describe su interfaz grafica; se resumen los principios en que se basan los seis tipos de modelos que el usuario puede elegir, y se presentan los resultados obtenidos.

  3. Modeling automation of hydraulic networks with application in training simulators; Automatizacion del modelado de redes hidraulicas con aplicacion en simuladores para entrenamiento

    Energy Technology Data Exchange (ETDEWEB)

    Roldan, Edgardo; Tavira, Jose [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The modeling of hydraulic networks is a fundamental task in the development of simulators for operator`s training. Having an automatic tool that eases the implementation of this models in a simulator, without the need that the user has to formulate and program his specific problem, represents a great saving of time and effort. In this paper the generalities of a computer program that allows the characterization and testing of models of hydraulic networks, are presented. A graphical interface is described; the principles on which the six types of models that the user can choose, are summarized and the results obtained, are presented. [Espanol] El modelado de redes hidraulicas es una tarea primordial dentro del desarrollo de simuladores para el entrenamiento de operadores. El contar con una herramienta automatica que facilite la implantacion de estos modelos en un simulador, sin que el usuario tenga que formular y programar su problema especifico, representa un gran ahorro en tiempo y esfuerzo. En este articulo se presentan las generalidades de un programa computacional que permite caracterizar y probar modelos de redes hidraulicas. Se describe su interfaz grafica; se resumen los principios en que se basan los seis tipos de modelos que el usuario puede elegir, y se presentan los resultados obtenidos.

  4. Estimation of production characteristic curves of geothermal wells and of the permeability of rocky formations through one single mass flow-pressure-enthalpy (W-P-h) measurement at the wellhead; Estimacion de curvas caracteristicas de produccion de pozos geotermicos y de permeabilidades de formaciones rocosas a partir de una sola medicion flujo masico-presion- entalpia (W-P-h) a boca de pozo

    Energy Technology Data Exchange (ETDEWEB)

    L Moya, Sara; Aragon, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The proposed methodology described ahead (Moya et al.,1996; Moya et al.,1997a, 1997b and 1997c) simplifies the construction of production characteristic curves of geothermal wells and of its associated thermal productivity, in requiring one single measurement of mass flow-pressure-enthalpy (W-P-h) at the wellhead. Therefore it is an ecological option, technically and economically more feasible. On the other hand, the methodology also allows to diagnose the rocky formation absolute permeability in the well feeding zone. This permeability is usually determined through well bottom pressure tests, than in some cases are difficult to interpret. The permeability inferred by means of the proposed technology represents a complementary tool for these field tests and for the laboratory measurements on drilling cores. [Espanol] La metodologia propuesta que se describe a continuacion [Moya et al., 1995d; Moya et al., 1996; Moya et al., 1997a, 1997b y 1997c] simplifica la construccion de curvas caracteristicas de produccion de pozos geotermicos y de su productividad termica asociada al requerir solo una medicion de flujo masico-presion-entalpia (W-P-h) a boca de pozo. Es por tanto una alternativa ecologica, tecnica y economicamente mas factible. Por otra parte, la metodologia tambien permite diagnosticar el valor de la permeabilidad absoluta de la formacion rocosa en la zona de alimentacion al pozo. Esta permeabilidad se determina usualmente a partir de pruebas de presion a fondo de pozo que en algunos casos son dificiles de interpretar. La permeabilidad inferida mediante la metodologia propuesta representa una herramienta complementaria a estas pruebas de campo y a las mediciones de laboratorio sobre nucleos de perforacion.

  5. Estimation of production characteristic curves of geothermal wells and of the permeability of rocky formations through one single mass flow-pressure-enthalpy (W-P-h) measurement at the wellhead; Estimacion de curvas caracteristicas de produccion de pozos geotermicos y de permeabilidades de formaciones rocosas a partir de una sola medicion flujo masico-presion- entalpia (W-P-h) a boca de pozo

    Energy Technology Data Exchange (ETDEWEB)

    L Moya, Sara; Aragon, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The proposed methodology described ahead (Moya et al.,1996; Moya et al.,1997a, 1997b and 1997c) simplifies the construction of production characteristic curves of geothermal wells and of its associated thermal productivity, in requiring one single measurement of mass flow-pressure-enthalpy (W-P-h) at the wellhead. Therefore it is an ecological option, technically and economically more feasible. On the other hand, the methodology also allows to diagnose the rocky formation absolute permeability in the well feeding zone. This permeability is usually determined through well bottom pressure tests, than in some cases are difficult to interpret. The permeability inferred by means of the proposed technology represents a complementary tool for these field tests and for the laboratory measurements on drilling cores. [Espanol] La metodologia propuesta que se describe a continuacion [Moya et al., 1995d; Moya et al., 1996; Moya et al., 1997a, 1997b y 1997c] simplifica la construccion de curvas caracteristicas de produccion de pozos geotermicos y de su productividad termica asociada al requerir solo una medicion de flujo masico-presion-entalpia (W-P-h) a boca de pozo. Es por tanto una alternativa ecologica, tecnica y economicamente mas factible. Por otra parte, la metodologia tambien permite diagnosticar el valor de la permeabilidad absoluta de la formacion rocosa en la zona de alimentacion al pozo. Esta permeabilidad se determina usualmente a partir de pruebas de presion a fondo de pozo que en algunos casos son dificiles de interpretar. La permeabilidad inferida mediante la metodologia propuesta representa una herramienta complementaria a estas pruebas de campo y a las mediciones de laboratorio sobre nucleos de perforacion.

  6. Simulador de chuva tipo empuxo com braços movidos hidraulicamente: fabricação e calibração Rainfall simulator thrust type with hydraulically moved arms: fabrication and calibration

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2012-12-01

    Full Text Available O uso de simuladores de chuva é fundamental em estudos de erosão hídrica pluvial. Com eles é possível controlar as condições experimentais, principalmente as características da chuva, e compreender melhor o processo erosivo do solo. Vários tipos de simulador de chuva foram desenvolvidos desde 1930 no mundo. Atualmente, o tipo Swanson é o mais utilizado. No entanto, um pequeno número desses simuladores está em pleno funcionamento no Brasil, devido ao alto grau de desgaste e às dificuldades de manutenção. O objetivo deste trabalho foi desenvolver um novo modelo de simulador de chuva, construído predominantemente em alumínio, desprovido de motor para rotação dos braços e movido hidraulicamente por empuxo. O simulador de chuva movido hidraulicamente por empuxo mantém em geral as características do modelo Swanson, sobretudo aquelas relacionadas às características de chuva produzida, tendo sido minimizados seu excesso de peso e a necessidade de uso de um motor a gasolina para movimento dos braços, denominado "Tipo Empuxo". Essas características tornaram o novo modelo mais leve, econômico, silencioso e de fácil manejo na área experimental do que o modelo Swanson, sendo possível deslocá-lo com apenas quatro pessoas. A intensidade da chuva correlacionou-se linear e positivamente com a pressão da água no manômetro.The use of rain simulators is fundamental to study rainfall erosion. They are used to monitor the experimental conditions, particularly the rain characteristics and to understand the soil erosion process better. Several types of rainfall simulators have been developed since 1930 around the world. Currently, the Swanson model is the most commonly used. However, a small number of these simulators is fully operational in Brazil, due to the high degree of wear and difficulties of maintenance. The purpose of this study was to develop a new rainfall simulator model, made mostly of aluminum, with no motor to rotate the

  7. Simulador cardiaco digital

    OpenAIRE

    Plaza Guingla, Vicente; Santin Loayza, Manuel; Yapur Auad, Miguel Eduardo

    2009-01-01

    presente trabajo ha sido diseñado con la finalidad de proporcionar al estudiante un dispositivo que permita simular un patrón de onda cardíaca normal y además que permita variar la frecuencia cardíaca, de manera que se ponga en práctica los conocimientos adquiridos al estudiar esta señal, y las alteraciones que se pueden presentar. Este dispositivo podrá ser utilizado para diagnóstico, ya que permite determinar si la señal cardíaca simulada de la persona, tiene un ritmo cardíaco norm...

  8. Importância do treinamento de residentes em eventos adversos durante anestesia: experiência com o uso do simulador computadorizado Importancia del entrenamiento de los practicantes (médicos en ejercicio en eventos adversos durante la anestesia: experiencia con el uso del simulador computadorizado Importance of critical events training for anesthesiology residents: experience with computer simulator

    Directory of Open Access Journals (Sweden)

    Domingos Dias Cicarelli

    2005-04-01

    durante los procedimientos anestésicos. Sin embargo, continua importante el entrenamiento de los médicos practicantes para este tipo de ocurrencia. El objetivo de este estudio fue evaluar el desempeño práctico de los médicos practicantes de Anestesiología en eventos adversos durante una anestesia simulada. MÉTODO: Fueron evaluados 17 médicos en especialización de primero y segundo años de Anestesiología (ME1 y ME2 y 5 instructores del Centro de Enseñanza y Entrenamiento (CEE del HCFMUSP (Título Superior en Anestesiología - TSA. Fue utilizado el simulador computadorizado Anesthesia Simulator Consultant (ASC versión 2.0 - 1995/Anesoft para realización de las simulaciones de los eventos. Los incidentes críticos escogidos fueron fibrilación ventricular (FV y choque anafiláctico. Después de la realización de la simulación, fueron impresos los resultados de cada participante, evaluados y puntuados las conductas adoptadas para resolver los incidentes críticos pre-determinados. Los participantes evaluaron el simulador a través de un cuestionario para ser respondido. RESULTADOS: No hubo diferencia estadística entre las medias obtenidas por los grupos, sin embargo, se notó una tendencia de un desempeño mejor de los grupos TSA y ME2 en la simulación de FV. En relación al choque anafiláctico, hubo una tendencia de desempeño mejor del grupo TSA. CONCLUSIONES: El entrenamiento para el diagnóstico y conductas en eventos adversos debe ser un foco de atención durante el entrenamiento de médicos practicantes y en la actualización de anestesiologistas. El uso del simulador puede ser una de las formas de realizar el entrenamiento en estas situaciones.BACKGROUND AND OBJECTIVES: Because of monitoring and drugs evolution, there has been a decrease in the incidence of critical events during anesthetic procedures. Despite this low frequency, critical event training for Anesthesiology residents remains important. This study aimed at evaluating Anesthesiology

  9. Método estadístico factorial a dos niveles aplicado en los experimentos de explotación de los Simuladores. // Two levels factorial statistical method applied in experiments of Simulators operation.

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    P. Moreno Quintana

    2002-05-01

    Full Text Available La introducción de los simuladores en el proceso de instrucción en el país cuenta con una dificultad al no conocerse el realimpacto de este tipo de equipamiento en la adquisición de las habilidades dentro del proceso de entrenamiento a que vadirigido.El empleo del método estadístico factorial a dos niveles permite la obtención de un modelo lineal de respuesta de laeficiencia, o calificación, en función de la forma cuantitativa de empleo de los diversos medios de entrenamiento y suscombinaciones.Este modelo es validado con un nivel de confianza calculado y puede ser optimizado por los métodos matemáticoscorrespondientes. Para esto se realiza un grupo de recomendaciones en la organización de los experimentos que han sidoobtenidos durante la aplicación de este método en diversas ocasiones.Palabras claves: Simuladores, modelación matemática, diseño de experimentos._____________________________________________________________________________Abstract.The introduction of simulators in the country´s instruction process deals with the difficulty of not knowing the real impactof this equipment in the acquisition of abilities within the training process. The use of the factorial statistical method at twolevels allows the obtaining of a linear model with answer about efficiency or qualification based on the quantitative form ofuse of diverse means of training and its combinations. This model is validated with a calculated level of confidence and canbe optimized by the corresponding mathematical methods. For this a group of recommendations is made in the organizationof experiments that have been obtained during the application of this method in diverse combnations.Key words: Simulators, mathematical modelation, experiment design.

  10. Simuladores para entrenamientos en la Fuerza Aérea Colombiana

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    José Fernando Sizza Moreno

    2014-01-01

    Full Text Available La simulación es una técnica que compromete ingeniería de software, ingeniería mecánica e ingeniería electrónica, además de emulación, que definen los modelos matemáticos para dotar a una máquina especificaciones funcionales, para la apariencia en tiempo real de comportamientos idénticos a los de su contraparte a imitar. Asimismo, emular es una reproducción de las operaciones de otro, intentando igualarlas e incluso excederlas. De esta manera, una máquina se dota con la simulación y la emulación en tiempo real, diseñando máquinas capaces de imitar y remedar otras, sin los riesgos, humanos o de infraestructura que involucra en la realidad, con la emulación acorde con la máquina a igualar. El entrenamiento puede ejecutarse en este tipo de máquinas, para proporcionar y evaluar las habilidades necesarias a desarrollarse en la vida real, con el fin de disminuir los costos y los tiempos que implican. Es así que el objetivo de este artículo es proporcionar una visión sobre simuladores aeronáuticos puestos en práctica en la Fuerza Aérea Colombiana.

  11. Initial Pressure Distribution in the Geothermal Field of Los Humeros, Puebla, Mexico; Distribucion de presion inicial en el campo geotermico de Los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, Victor M.; Izquierdo, Georgina; Aragon, Alfonso; Barragan, Rosa Maria; Garcia, Alfonso [Instituto de Investigaciones Electricas (Mexico); Pizano, Arturo [Comision Federal de Electricidad (Mexico)

    2001-09-01

    To obtain the undisturbed distribution of pressures of a field flow, a significant amount of data concerning geological, geochemical, geophysical, and field drilling and engineering aspects, from 42 wells located at the geothermal field of Los Humeros, was analysed. Based on the studied data, models of the field pressure distribution in its initial state were developed. The models reveal the existence of at least two deposits. One of them, the most superficial, is located between 1025 and 1600 meters over the sea level, and from its excellent congruence with the pressure profile of a boiling water column, it may be considered as a predominantly liquid field. The pressure profile of this field is that of a boiling water column, at a temperature of about 300-330 Celsius degrees. The second field is below 850 meters over the sea level and from the known data it reaches at least 100 meters over the sea level. It is considered a low-liquid saturated field. The temperatures of the wells supplied by this field were estimated to be about 300-40 Celsius degrees. [Spanish] Para inferir las distribuciones de presion no perturbadas del fluido del yacimiento, se analizo una considerable cantidad de informacion relacionada con los aspectos geologicos, geoquimicos, geofisicos, de perforacion e ingenieria de yacimientos, correspondiente a 42 pozos del camo geotermico de Los Humeros, Puebla. Sobre la base de los datos analizados se desarrollaron modelos de distribucion de la presion del yacimiento en su estado inicial. Dichos modelos revelan la existencia de, cuando menos, dos yacimientos. El primero y mas superficial se encuentra localizado entre 1,600 y 1,025 metros sobre el nivel del mar (msnm), y dada su excelente concordancia con el perfil de presion correspondiente a una columna de agua en ebullicion, puede afirmarse que se trata de un yacimiento de liquido dominante. El perfil de presion de este yacimiento corresponde a una columna de agua en ebullicion de 300 a 330

  12. Uso de simuladores en ginecología y obstetricia: Experiencia en la enseñanza de pregrado Use of medical simulators in obstetrics and gynaecology: Experience in undergraduate education

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    Grazzia Rey

    2006-12-01

    Full Text Available Introducción: Los cursos de Ginecología y Obstetricia se dictan en el penúltimo año de la carrera de Doctor en Medicina y representan el primer contacto curricular de los estudiantes con la disciplina. El perfil del egresado del plan de estudios vigente se orienta a la formación de medico generalista, por lo que el egresado debe ser competente en un numero básico de destrezas en el área ginecobstétrica. Objetivos: El objetivo del presente trabajo es introducir el uso de simuladores en la enseñanza del pregrado de ginecología y obstetricia. Metodología: En el transcurso del curso de ginecología del año 2003 los estudiantes fueron divididos en forma aleatorizada en dos grupos, uno de los cuales realizó su entrenamiento con simuladores. Se realizó un seguimiento del aprendizaje por medio de planillas de verificación. Resultados: De los resultados surge que los estudiantes del grupo que realizó su entrenamiento con simuladores tuvieron mas oportunidades de realizar las maniobras sobre todo aquellas que implican mayor dificultad como ser la colocación del especulo y el examen vaginal. Conclusiones: De acuerdo a esto se podría afirmar que la utilización de simuladores constituye una buena herramienta para la adquisición de destrezas en el área gineco obstétrica, y pueden ser una alternativa para la enseñanza a nivel del pregrado.Introduction: The courses in gynaecology and obstetrics are given during the seventh year of the medicine career and represent the students’ first contact with the discipline. Most graduates from our medical school eventually become GPs, so they must be trained in a number of basic skills in obstetrics and gynaecology. Aims: To introduce the use of medical simulators in undergraduate courses of obstetrics and gynaecology. Methodology: During the gynaecology course in the 2003 academic year, students were randomly divided into two groups. The experimental group did their training with medical

  13. Desarrollo de simuladores para procesos industriales. Parte I. (Colada continua

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    Ramírez, A.

    2006-06-01

    Full Text Available This work was written for illustrating the development of computer simulators for production process. As an example a simulator for continuous casting process was made, this is the most popular method to produce some steel products like billets and slabs. The simulator (SSCC was programmed by the present authors in C++; but mathematical procedures, algorithms and flow charts shown here can be used as a base in any other programming language. This is the first part of the work; it is focused to the development of some computational tools to describe the real continuous casting process

    Este trabajo se realiza con el objeto de ilustrar el desarrollo de simuladores para procesos industriales; como ejemplo se realizó un sistema de simulación para representar el proceso de colada continua que es el proceso más común para la producción de perfiles de acero. El sistema de simulación para colada continua (SSCC fue programado por los presentes autores en lenguaje C++; sin embargo, los procedimientos matemáticos, algoritmos y diagramas de flujo ilustrados en este trabajo pueden ser programados en cualquier lenguaje de programación. Esta primera parte del trabajo se enfoca a desarrollar herramientas de cálculo para representar lo que sucede físicamente durante el proceso de colada continua.

  14. SIMULADOR INTERACTIVO DE REDES INALÁMBRICAS BASADAS EN IEEE802.11a

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    Arturo Infante Riello

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Este artículo presenta los fundamentos y características básicas del diseño de un simulador de redes inalámbricas basadas en el estándar IEEE802.11a, mostrando aspectos de la capa física, canal de radio, programación e interfaz de usuario.

  15. Propuesta de adecuación para optimización del sistema de seguridad industrial y salud ocupacional en el área operativa del simulador de vuelo

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Acero Gómez

    2006-01-01

    Full Text Available La norma OHSAS 18001, expone los elementos estructurales de un Sistema de Gestión de Prevención de Riesgos Laborales para revisar, gestionar y mejorar el control de los riesgos laborales; y se toma como referencia para los procesos y procedimientos que se llevan a cabo en el simulador de vuelo, para conocer si éste se encuentra en las condiciones óptimas de ser certificado.

  16. DISEÑO DE UN SIMULADOR DE PROCESOS QUÍMICOS PARA USO COLABORATIVO Y DIDÁCTICO

    Directory of Open Access Journals (Sweden)

    Susana Martínez Riachi

    2014-04-01

    Full Text Available En muchas carreras de ingeniería química, los estudiantes aprenden a utilizar simuladores comerciales, por lo tanto el futuro ingeniero depende de ellos. En vez de usar un "paquete cerrado" sin conocer su principio de funcionamiento, es necesario realizar esfuerzos para diseñar un software de código abierto capaz de conectar operaciones unitarias, con módulos estándar para resolver las operaciones básicas de ingeniería química y lo suficientemente versátil para la incorporación de nuevos módulos de terceros (plugin, con un complemento opcional y educativo, definido por el desarrollador. El objetivo es crear una plataforma para fines académicos o industriales con documentación colaborativa a través de un Wiki, con mención de los créditos para los participantes, dada por un Comité científico tecnológico nombrado ad hoc. Habrá foros de ayuda y discusión. Lazarus se propone como herramienta de desarrollo, debido a su alta velocidad de cálculo y por ser multiplataforma. El análisis se realizará usando UML.PALABRAS CLAVE: simuladores; abierto; operaciones unitarias; versátil; LazarusDESIGN OF A SIMULATOR OF CHEMICAL PROCESSES FOR COLLABORATIVE AND DIDACTIC USEABSTRACTIn many chemical engineering careers, students learn to use commercial simulators; therefore the future engineer depends on them. Instead of using a "closed package" without knowing its principle of operation, it is necessary to make efforts to design an open source software able to connect unit operations, with standard modules for solving chemical engineering basic operations and versatile enough for the incorporation of new third party modules (plugin, with an optional and educational complement, defined by the developer. The goal is to create a platform for either academic or industrial purposes with collaborative documentation through a Wiki, with mention of credits for the participants, given by a technological Scientific Committee appointed ad hoc. There

  17. Distribution electric system simulator to support decision-making for CFE (Federal Electric Commission) Distribution Control Centers; Simulador del Sistema Electrico de Distribucion para apoyo en la toma de decisiones en Centros de Control de Distribucion de la CFE

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa Reza, Alfredo; Quintero Reyes, Agustin; Garcia Mendoza, Raul; Calleros Torres, Tito Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Borjas Diaz, Jesus Fidel; Sierra Rodriguez, Benjamin; Torres Abrego, Rafael [Comision Federal de Electricidad (Mexico)

    2011-07-01

    This article presents the physical, logical and functional architecture designed to integrate the Electric Distribution System (EDS) simulator developed for the CFE and the electric energy Distribution Control Centers in Mexico. The objective of the EDS simulator is to integrate engineering distribution functions (power flow, short circuit, optimal reconfiguration and reliability, among others) and an expert system (Case-based Reasoning) to aid the process of information analysis, decision-making and the capacity-building of the CFE's Regional and Zonal Distribution Control Centers. The EDS simulator has been installed, updated and is operational in the Tampico Zone and the Gulf Division Distribution Center, as an established product that continually evolves along with the actual operating dynamics. [Spanish] Se presenta la arquitectura fisica, logica y funcional disenada para integrar el simulador del Sistema Electrico de Distribucion (SED) desarrollado para la Comision Federal de Electricidad (CFE) y los Centros de Control de Distribucion de energia electrica en Mexico. El objetivo del simulador del SED es integrar funciones de ingenieria de distribucion (flujo de potencia, corto circuito, reconfiguracion optima, confiabilidad, entre otras) y un sistema experto (Razonamiento Basado en Casos) para apoyar el proceso de analisis de informacion, la toma de decisiones y la capacitacion en los Centros de Control de Distribucion Zonales y Regionales de CFE. El Simulador del SED se encuentra instalado, actualizado y en operacion en la Zona Tampico y en la Division de Distribucion Golfo Centro como un producto consolidado y en constante evolucion a la par de la dinamica operativa real.

  18. Toma de decisiones en las Pymes Mexicanas: El valor de la estratégico de un simulador presupuestario de tipo Industrial (Decision making on mexican SME’S: The strategic value of an industrial type budget simulator

    Directory of Open Access Journals (Sweden)

    Rafael Espinosa Mosqueda

    2014-09-01

    Full Text Available En la Grecia clásica, la excelencia del ciudadano consistía en el cultivo de tres virtudes específicas: forta- leza, templanza y la dicaiosine o justicia. Estas virtudes formaban un ciudadano relevante, útil y espléndido. Platón añadió una cuarta virtud, la prudencia, el hábito cualidad del hegemone, el conductor, el guía y también el comandante del ejército, el líder. A estos se instruía para saber juzgar sobre un problema o un caso concreto, así como para dirigir estratégicamente. Extrapolado al mundo empresarial actual, se convierte en la destreza o capacidad para la toma de decisiones. En concordancia, aquí se presenta un instrumento de apoyo en la toma de decisiones, diseñado para los directivos de las PYMES industriales mexicanas, el cual está fundado en el modelo Costo-Volumen-Utilidad (CVU. El“Simulador Presupuestario para PYMES del Sector Industrial”, aplicado en veintitrés giros indus- triales de la zona Laja-Bajío, en el Estado de Guanajua- to, demostró ampliamente su confiabilidad al permitir al directivo, emprendedor o desarrollador de empresas visualizar de una forma documentada su actuar en los negocios. El simulador puede ser adaptado y adoptado para otros ramos y latitudes, con lo cual el empresario PYME tendrá una ventaja competitiva.   Abstract In classic Greece, a citizen’s excellence was measured by his fostering of three specific virtues: fortitude, temperance and dicaiosine or justice. These virtues formed a relevant, utile and splendid citizen. Plato added a fourth virtue, prudence, a quality attributed to the hegemone, the driver, the guide, the military commander, the leader. They were taught to judge quickly on a concrete problem or case, as well as to strategically lead. Extrapolating this concept to the current world, it becomes the ability or capacity to make decisions.Accordingly, a support instrument for decision making is presented here, designed for managers of Mexican industrial

  19. Biomechanical analysis of the support in race walking. Relationship between footprint, subtalar joint angles, and plantar pressures Análisis biomecánico del apoyo plantar en la marcha atlética. Relación entre la huella plantar, ángulos de la articulación subastragalina y presiones plantares

    Directory of Open Access Journals (Sweden)

    M. Meana

    2010-09-01

    mientras marchaban a velocidad individual de competición. Se calcularon las presiones máximas en cada región del pie y los valores máximos y mínimos de los tres ángulos que describen la articulación subastragalina. La máxima pronación ha mostrado ser mayor que la descrita en la marcha común y similar a la de la carrera (-13.6±3.90. Al inicio del apoyo, la articulación subastragalina se encuentra entre la marcha y la carrera, sugiriendo un ajuste en su mecanismo amortiguador según el tipo de locomoción. La zona que registra mayores presiones es el retropié externo (21.02 kPa/kg yseguida lu ego del antepié interno (13.12 kPa/kg, a diferencia de la carrera, que presenta presiones máximas similares. Los sujetos con pies más planos tienden a apoyar con la cara interna del pie (r=-0.713 y con la pierna inclinada medialmente (r=0.874. Asimismo, los marchadores con pies más cavos registran mayores presiones en la parte externa del retropié y, mientras que los más planos lo hacen en la parte interna del mediopié.
    Palabras Clave: Biomecánica, marcha atlética, huella plantar, articulación subastragalina, presiones plantares.

  20. Entrenamientos de automovilismo: ¿simulación o realidad? Un análisis de los costos y beneficios sociales

    OpenAIRE

    Marechal, Melisa

    2014-01-01

    La contaminación ambiental y el riesgo de accidentes graves, son dos de los costos sociales de mayor consideración causados por el uso de automóviles. La presente investigación tiene como propósito analizar la conveniencia de realizar entrenamientos de automovilismo sustituyendo al auto real por entrenamientos en simulador, centrando el estudio en el "Turismo Carretera" una categoría de automovilismo popular en Argentina. Para evaluar los costos y beneficios del entrenamiento en simulador, la...

  1. Somnolencia y fatiga materna en los primeros años de crianza y ejecución en la conducción evaluada en simulador

    OpenAIRE

    Sánchez García, M. Mar

    2017-01-01

    RESUMEN DE LA TESIS DOCTORAL Somnolencia y fatiga materna en los primeros años de crianza y ejecución en la conducción evaluada en simulador El nacimiento de un bebé y la crianza posterior durante la primera infancia supone un considerable esfuerzo para madres y padres, que provoca cambios profundos en la familia, tanto si se trata del primer hijo/a como de la incorporación de un nuevo miembro más a la familia. Un bebé recién nacido necesita atención constante por parte de sus cuidador...

  2. Study of thermal behavior of the adobe with the simulator DOE 2.1E; Estudio de comportamiento termico del adobe con el simulador DOE 2.1E

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Anibal; Gallegos, Ricardo; Bojorquez, Gonzalo [Universidad Autonoma de Baja California, Mexicali, Baja California (Mexico)

    2000-07-01

    bibliografia especializada. A partir de la informacion proporcionada al simulador se determino que la vivienda con muros de adobe, tiene ventajas termicas respecto a las viviendas construidas con bloque de concreto y ladrillo de barro. La vivienda de adobe presenta una disminucion de carga termica del 13% con respecto a la de bloque de concreto y del 3.44% con respecto a la de ladrillo de barro.

  3. Prototipo de simulador de tornado para el combate Aéreo No. 3 (CACOM 3 de la Fuerza Aérea Colombiana (FAC

    Directory of Open Access Journals (Sweden)

    Jorge Mario Cárdenas Cabrera

    2012-09-01

    El comando CACOM 3 de la Fuerza Aérea Colombiana (FAC ha tomado la iniciativa en este aspecto y se ha dado a la tarea de estudiar este fenómeno, trabajando en el diseño de un simulador de tornados a escala, con base en el ya existente, desarrollado por el phD. Harald Eddens, introdujo modificaciones que permitan, además de generar el fenómeno, medir y controlar a través de dispositivos electrónicos algunas variables ambientales. Estos dispositivos permitirán iniciar estudios desde el comando y servir de apoyo para labores de educación de la población vulnerable en cuanto a entender cómo se forma un tornado.

  4. Pressure surge generated by start up of pumping equipment in pipes to pressure. Application to a real case; Transitorios hidraulicos generados por arranque de equipo de bombeo en conducciones a presion. Aplicacion a un caso real

    Energy Technology Data Exchange (ETDEWEB)

    Carmona Paredes, L.G.; Carmona Paredes, R.B. [Instituto de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2000-12-01

    Water closed conduits are commonly designed with special attention paid to pressure surges due to pumping failures. In some particular cases, such at the Rio Yaqui-Guaymas water pipeline system, pressure surges due to pumping start ups are as high and dangerous as those produced by pumping failures. New subroutines were thus developed and included in the Closed Conduit Flow Transient Model developed by the Instituto de Ingenieria of the Universidad Nacional Autonoma de Mexico. This paper presents the mathematical model and its numerical solution using the Method of Characteristics and the Newton-Raphson Method. With the new modeling system it is possible to evaluate the pressure fluctuation time series due to start up at any pumping system. Using this new system a reliable explanation of bursts at the Rio Yaqui-Guaymas system could be set forth. [Spanish] Al disenar conducciones a presion, es comun que se preste especial atencion a los transitorios hidraulicos generados por paros de emergencia de los equipos de bombeo. En el acueducto rio Yaqui-Guaymas, Sonora, Mexico, los transitorios generados al poner en marcha los equipos de bombeo son tan importantes como los producidos por disparo de bombas. En el Instituto de Ingenieria de la UNAM, se desarrollo e implanto en su programa de simulacion de transitorios hidraulicos en tuberias a presion una subrutina para simular el arranque de equipos de bombeo. El modelo matematico esta formado por el conjunto de ecuaciones dinamica y de continuidad, asi como la condicion de frontera que describe el arranque de las bombas. Se reescriben las ecuaciones dinamica y de continuidad, con el metodo de las caracteristicas y se plantea un sistema de ecuaciones no lineales, el cual se resuelve con el metodo de las caracteristicas y se plantea un sistema de ecuaciones no lineales, el cual se resuelve con el metodo de newton-raphson. La simulacion del arranque de las bombas del acueducto en estudio, arroja valores de las cargas

  5. Modelo simulador para entrenamiento en neuroendoscopia y neuroanatomía Simulating model for training in neuroendoscopy and neuroanatomy

    Directory of Open Access Journals (Sweden)

    Enrique Jongh Cobo

    2005-03-01

    Full Text Available Se presenta un modelo simulador auxiliar, para finalidades docentes, idóneo para el adiestramiento en el laboratorio en las técnicas de neuroendoscopía (en el caso de residentes y especialistas jóvenes en Neurocirugía y también para el estudio de la anatomía del sistema ventrículo-cisternal encefálico (para estudiantes de Medicina y otras áreas de la salud. Se confecciona con cerebros de cadáveres previamente preparados en formol y envueltos en bolsas de nylon, que simulan la duramadre. Luego se instalan en los cráneos, cortados aproximadamente 3 cm sobre el nasión y hasta 3 cm sobre la protuberancia occipital externa. El endoscopio se introduce por las vías habituales y se pueden realizar observaciones anatómicas o simular operaciones. Los modelos pueden ser preparados por los propios usuarios y presentan un ambiente muy similar al de las operaciones realesAn auxiliary simulating model for teaching ends is presented. It is ideal for the training of neuroendoscopic techniques in the laboratory (in the case of residents and young specialists in Neurosurgery and also for studying the anatomy of the ventriculocisternal encephalic system (for medical students and other health areas. It is made of brains from corpses previously prepared with formol and wrapped up in nylon bags that simulate the dura mater. Then, they are installed in the crania, cut approximately 3 cm over the nasion and up to 3 cm above the external occipital protuberance. The endoscopy is introduced by the habitual routes and anatomical observations can be made, or operations can be simulated. The models may be prepared by the own users and they present an environment very similar to that of the real operations

  6. Pressure surges generated by the polling out of pumping equipment in conduction by pressure. Application of a real case; Transitorios hidraulicos generados por arranque de equipos de bombeo en conducciones a presion. Aplicacion a un caso real

    Energy Technology Data Exchange (ETDEWEB)

    Carmona-Perales, L. G.; Carmona-Perales, R. B. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-12-01

    Water closed conduits are commonly designed with special attention paid to pressure surges due to pumping failures. In some particular cases, such at the Rio Yaque-Guaymas water pipeline system, pressure surges due to pumping start up are as high and dangerous as those produced by pumping failures. New subroutines were thus developed and included in the Closed Conduit Flow Transient Model developed by the Instituto de Ingenieria of the Universidad Nacional Autonoma de Mexico. This paper presents the mathematical model and its numerical solution using the Method of Characteristics and the Newton-Raphson Method. With the new modelling system it is possible to evaluate the pressure fluctuation time series due to start up at any pumping system. Using this new system a reliable explanation of bursts at the Rio Yaqui-Guaymas pipeline system could be set forth. [Spanish] Al disenar conducciones a presion, es comun que se presente especial atencion a los transitorios hidraulicos generados por paros de emergencia de los equipos de bombeo. En el acueducto rio Yaqui-Guaymas, Sonora, Mexico, los transitorios generados al poner en marcha los equipos de bombeo son tan importantes como los productos por disparo de bombas. En el Instituto de Ingenieria de la UNAM, se desarrollo e implanto en un programa de simulacion de transitorios hidraulicos en tuberias a presion una subrutina para simular el arranque de equipos de bombeo. El modelo matematico esta formado por el conjunto de ecuaciones dinamica y de continuidad, asi como la condicion de frontera que describe el arranque de las bombas. Se rescriben las ecuaciones dinamicas y de continuidad, con el metodo de las caracteristicas y se plantea un sistema de ecuaciones no lineales, el cual se resuelve con el metodo de Newton-Raphson. La simulacion del arranque de las bombas del acueducto en estudio, arroja valores de las cargas piezom ricas maximas y minimas mayores que la resistencia de la tuberia y menores que la topografia del

  7. Implementación de un sistema de telemetría de bajo costo para medición de presiones plantares

    Directory of Open Access Journals (Sweden)

    Jorge Humberto Torres

    2006-11-01

    Full Text Available Se implementó un prototipo de comunicación inalámbrica para medición de presiones plantares, empleando un protocolo de comunicación unidireccional y utilizando un microcontrolador y módulos de transmisión y recepción de radiofrecuencia (RF de bajo costo fabricados por la empresa Linx Technologies (Merlín, Oregon, USA. Se presenta la forma utilizada para detección de errores, codificación y sincronización. La transmisión de datos se realizó a 5 Kbps en las frecuencias disponibles de 315 y 433 MHz. Las frecuencias empleadas para la transmisión y recepción de la señal RF no presentaron niveles de interferencia superiores al umbral de ruido. La transmisión inalámbrica evita el uso de cables y proporciona más comodidad de uso del sistema de medición por un paciente. Detalles de la caracterización de los sensores y del diseño y la implementación del sistema de medición se han reportado previamente./ A prototype of wireless communication for the measurement of plantar pressures was implemented by employing a one-way communications protocol and by using a microcontroller and low cost modules for RF transmission and reception from the company Linx Technologies (Merlín, Oregon, USA. The method for error detection, codification and synchronization is presented. Data transmission was carried out at 5 Kbps in the available frequencies of 315 and 433 MHz. The employed frequencies for the transmission and reception of the RF signal did not present significant interference above noise level. The wireless communication avoids the use of cables and provides more comfort in the use of the measurement system by a patient. Details of sensor characterization and the design and implementation of the measurement system have been reported previously.

  8. ADAPTABILIDAD DE LAS FAMILIAS AGRÍCOLAS ANTE PRESIONES ECONÓMICAS Y ECOLÓGICAS: UN CASO DE CAFÉ DE ALTURA EN LEÓN CORTÉS, COSTA RICA

    Directory of Open Access Journals (Sweden)

    Jorge Andrey Valenciano Salazar

    2012-05-01

    Full Text Available Resumen Los medios de vida de las familias productoras de café de altura están ligados a la finca. Esta relación tan marcada (familia – finca los hace vulnerables a presiones externas que alteran el funcionamiento cotidiano interno de la unidad productiva. Dentro de estas presiones externas se encuentran los bajos precios, efectos climáticos y plagas en el cafetal. El artículo busca identificar los impactos que ejercen dichas presiones sobre los medios de vida de las familias cafetaleras del cantón de León Cortés, además se intenta mostrar las estrategias que han seguido estas unidades familiares para poder soportar y reponerse a los impactos generados por el clima, las plagas y la inestabilidad de precios del café. Las familias han generado diversas “estrategias de adaptación” en relación con los precios bajos, las organizaciones de productores han buscado nuevas alternativas de comercialización del café, tales como mercado justo y denominación de origen; además, han buscado la generación de un mayor valor agregado mediante la diversificación del producto final enfocado al café de calidad y a la presentación de café molido. Por su parte, las unidades familiares han buscado alternativas de diversificación como la siembra de aguacate. Para combatir las plagas los productores se han enfocado en la introducción de prácticas de conservación de suelos, mejorar sistemas de recolección e introducir sombra en los cultivos; el combate químico también ha sido una estrategia. Por último, la presión del clima no había sido muy tomada en cuenta por los caficultores de la zona, sin embargo, la Tormenta Alma sufrida en el año 2008 hizo que los caficultores comenzaran a pensar en un manejo adecuado y sostenible de la finca que minimice el riesgo climático. Abstract Livelihoods of family coffee growers are strongly determined by their farm. This makes families vulnerable to external shocks that affect the operations in the

  9. Development of a simulator for personnel training on nuclear power plants. The authors` experience in the Federal Republic of Germany; Desarrollo de un simulador para entrenamiento de personal de centrales nucleares. Experiencia de los autores en la Republica Federal de Alemania

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, P; Kogan, A; Garzon, D

    1991-12-31

    This work describes the stages necessary to carry out the development of a full scope simulator for personnel training on nuclear power plants operation. (Author). [Espanol] Este trabajo describe los pasos o etapas necesarios para llevar adelante el desarrollo de un simulador de amplio alcance (full scope simulator) para entrenamiento de personal de operacion de centrales nucleares. (Autor).

  10. MACRO simulator (version 5.0 for predicting atrazine herbicide behavior in brazilian latosols Simulador MACRO (versão 5.0 na predição do comportamento do herbicida atrazina em latossolos brasileiros

    Directory of Open Access Journals (Sweden)

    Fernanda Carla Wasner Vasconcelos

    2013-06-01

    Full Text Available The knowledge of pesticides behavior is fundamental for understanding the environmental impact caused by these products. However, related field experiments are time consuming and expensive. The MACRO® simulator allows to predicting the leaching of pesticides through the soil profile and the possible environmental contamination. The objective of this work was to study the percolate behavior and the atrazine leaching in two contrasting Latosols using the MACRO® simulator. The MACRO® simulator was adequate to predict atrazine behavior under the studied conditions and it can be used for the risk evaluation of atrazine contamination in surface and underground waters.O conhecimento do comportamento de pesticidas é fundamental para a compreensão do impacto ambiental causado por esses produtos. No entanto, os experimentos de campo consomem tempo e investimento. O simulador MACRO® permite prever a lixiviação de pesticidas ao longo do perfil do solo e a possível contaminação ambiental. Objetivou-se, neste trabalho, estudar o comportamento do percolado e a lixiviação do herbicida atrazina em dois Latossolos contrastantes, usando o simulador MACRO® . A simulação pelo MACRO® foi adequada para prever o comportamento da atrazina sob as condições estudadas e pode ser utilizada para a avaliação dos riscos de contaminação por esse herbicida em águas superficiais e profundas.

  11. Análisis experimental del simulador de conducción UPV-DGT para la evaluación de conductores con discapacidades severas que conducen con Joysticks de 4 vías

    OpenAIRE

    BRUNA REMIRO, FRANCISCO JAVIER

    2016-01-01

    [ES] El objetivo de este TFG es el análisis experimental del simulador de conducción FIATDGT para la evaluación de conductores con discapacidades severas. Para poder determinar si es válido, se ha realizado un análisis estadístico entre un grupo de control ( personas sin discapacidad ) y un grupo de experimental ( personas con discapacidades) de los datos obtenidos de una batería de pruebas seleccionadas previamente, las cuáles serán comunes para ambos grupos, par...

  12. Control y presión al comer en madres de preescolares costarricenses, y su relación con la clase social, la escolaridad, las prácticas de alimentación temprana y el índice de masa corporal de sus hijos e hijas

    OpenAIRE

    Alejandro Chacón-Villalobos

    2011-01-01

    El objetivo planteado en este trabajo fue el de caracterizar la presion y el control al comer que ejercen madres de preescolares costarricenses de clase alta y baja, evaluando relaciones con el IMC de sus hijos, el tipo de lactancia, la ablactacion, la escolaridad de la madre y su dedicacion al hogar. Para ello se solicito a 102 madres de clase alta y 121 de clase baja completar una encuesta validada (alpha de Cronbach de 0,7) basada en escalas de Likert, para cuantificar, ademas de la inform...

  13. Development and implementation of an interface control-process and of additional models in the simulator of combined cycle units; Desarrollo e implantacion de una interfaz control-proceso y de modelos adicionales en el simulador de unidades de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez R, Rogelio E; Ramirez G, Miguel; Melgar G, Jose L; Codero C, Juan C; Romero J, Guillermo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this article are described the design and implementation of an interface control-process and the formulation of the process models for the simulation of the vibration amplitudes of the steam and gas turbines and of the monitoring system of gas discharges, which comprise a simulator of total reach of combined cycle units. These three systems had to be developed and implemented in the simulator of combined cycle units, that the Instituto de Investigaciones Electricas (IIE) developed for the Comision Federal de Electricidad (CFE), with the purpose of solving different problematic caused by the use of a platform of commercial software for the construction of simulators. The problematic presented by the platform of software is briefly described, as well as the solutions contributed with respect to the interconnection of signals control-process, and to the lack of models of the mechanical part of the steam and gas turbines, and of the monitoring system of polluting emissions. [Spanish] En este articulo se describen el diseno e implantacion de una interfaz control-proceso y la formulacion de los modelos de proceso para la simulacion de las amplitudes de vibracion de las turbinas de gas y de vapor y del sistema de monitoreo de emisiones de gases, los cuales forman parte de un simulador de alcance total de unidades de ciclo combinado. Estos tres sistemas tuvieron que ser desarrollados e implementados en el simulador de unidades de ciclo combinado, que el Instituto de Investigaciones electricas (IIE) desarrollo para la Comision Federal de Electricidad (CFE), con el fin de resolver diferentes problematicas ocasionadas por la utilizacion de una plataforma de software comercial para la construccion de simuladores. Se describen brevemente las problematicas presentadas por la plataforma de software, asi como las soluciones aportadas en lo relativo a la interconexion de senales control-proceso, y a la falta de modelos de la parte mecanica de las turbinas de gas y de vapor, y

  14. Response to exploitation (1982-2002) of the Los Azufres, Michoacan (Mexico) geothermal field. Part I: North Zone; Respuesta a la explotacion (1982-2003) del yacimiento geotermico de Los Azufres, Michoacan (Mexico). Parte I: Zona Norte

    Energy Technology Data Exchange (ETDEWEB)

    Arellano G, Victor Manuel; Barragan R, Rosa Maria [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Torres R, Marco Antonio; Sandoval M, Fernando [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    2004-12-01

    This work studies the thermodynamic evolution of the Los Azufres northern zone reservoir fluids as a response of exploitation since 1982 to 2002 is presented. Thermodynamic conditions for reservoir fluids were estimated using the WELFLO heat-and flow-well simulator, using production data as the input. The initial thermodynamic conditions of the north zone wells indicated the presence of compressed liquid; also it was noticed that the first response to exploitation was a pressure drop and an enthalpy increase, while the long term response indicated a very small pressure change but a high enthalpy increment. The analysis of production, chemical and isotopic (d18O, dD) data in this zone showed interference effects of fluids reinjected in well Az-52 on well Az-5; and in well Az-15 on wells Az-13, Az-28 and Az-43. At the present time due to the low injection flow rates, this effect is minimal. [Spanish] En este trabajo se presenta un estudio sobre la evolucion termodinamica de los fluidos de la zona norte del yacimiento de Los Azufres desde el inicio de su explotacion en 1982 hasta el ano 2002, considerando las condiciones de fondo de pozos del campo, como respuesta a la extraccion e inyeccion de fluidos. Las condiciones termodinamicas de los fluidos del yacimiento se estimaron mediante el simulador del flujo de fluidos y calor en pozos {sup W}ELFLO{sup ,} a partir de datos de produccion. Las condiciones termodinamicas iniciales de los fluidos de la zona norte de campo se encontraron en la region de liquido comprimido; la primera respuesta a la explotacion consistio en una disminucion de presion y un incremento en la entalpia. A largo plazo, se observaron cambios muy pequenos en la presion y grandes incrementos en la entalpia. El analisis de datos quimicos, isotopicos (d18O, dD) y de produccion de pozos en la zona norte evidencio la ocurrencia de interferencia de fluidos de reinyeccion del pozo Az-52 con el pozo Az-5 y del pozo Az-15 con los pozos Az-13, Az-28 y Az 43

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

    Directory of Open Access Journals (Sweden)

    Aldemar Garduño Hernández

    2012-02-01

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

  16. Sensibility analysis of the pearl model for pesticide leaching in the State of Mato Grosso do Sul, Brazil Análise de sensibilidade do simulador pearl para lixiviação de pesticidas no estado de Mato Grosso do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Rômulo P. Scorza Júnior

    2011-10-01

    Full Text Available For an accurate use of pesticide leaching models it is necessary to assess the sensitivity of input parameters. The aim of this work was to carry out sensitivity analysis of the pesticide leaching model PEARL for contrasting soil types of Dourados river watershed in the state of Mato Grosso do Sul, Brazil. Sensitivity analysis was done by carrying out many simulations with different input parameters and calculating their influence on the output values. The approach used was called one-at-a-time sensitivity analysis, which consists in varying independently input parameters one at a time and keeping all others constant with the standard scenario. Sensitivity analysis was automated using SESAN tool that was linked to the PEARL model. Results have shown that only soil characteristics influenced the simulated water flux resulting in none variation of this variable for scenarios with different pesticides and same soil. All input parameters that showed the greatest sensitivity with regard to leached pesticide are related to soil and pesticide properties. Sensitivity of all input parameters was scenario dependent, confirming the need of using more than one standard scenario for sensitivity analysis of pesticide leaching models.Para o uso confiável de simuladores da lixiviação de pesticidas, é necessária a avaliação da sensibilidade dos dados de entrada. O objetivo deste trabalho foi realizar a análise de sensibilidade do simulador da lixiviação de pesticidas PEARL para tipos de solos contrastantes da Bacia Hidrográfica do Rio Dourados, no Estado de Mato Grosso do Sul, Brasil. A análise de sensibilidade foi feita através da execução de várias simulações com dados de entrada diferentes e calculando suas influências nos resultados obtidos. O método usado foi o denominado de análise de sensibilidade "individual", onde se varia cada dado de entrada de forma independente enquanto se mantêm constantes, os outros dados de entrada, conforme

  17. Análisis de las presiones plantares y su relación con la velocidad de la pelota durante el golpeo paralelo de derecha en tenis

    Directory of Open Access Journals (Sweden)

    Buscar hemeroteca Índice · 93 Apuntes para el siglo XXI Los Juegos Olímpicos de Pekín 2008: ¿avance o retroceso? Ciencias aplicadas a la actividad física y el deporte El movimiento gimnástico del Este (1.ª parte El movimiento gimnástico del Este (2.ª parte Actividad física y salud Prueba de campo específica de valoración de la resistencia... Educación física Revisión de los distintos aspectos de la influencia de los padres... Pedagogía deportiva Incidencia del número de atacantes en la defensa de primera... La motivación para la práctica en la iniciación al fútbol:... Entrenamiento deportivo Biomecánica aplicada al diseño de una Herramienta de Evaluación... Gestión deportiva, ocio activo y turismo Metodología para el análisis y evaluación de la seguridad... Mujer y deporte Evolución de las jugadoras en las selecciones españolas de... Arte y deporte NUESTRA PORTADA Juegos infantiles Tesis doctorales Deporte y democratización en un periodo de cambio. Evolución... Las fundaciones deportivas españolas La formación del Animador Deportivo en el marco de la Asociación... Análisis de las presiones plantares y su relación con la velocidad... Hemeroteca > Número 93 > Análisis de las presiones plantares y su relación con la velocidad de la pelota durante el golpeo paralelo de derecha en tenis Análisis de las presiones plantares y su relación con la velocidad de la pelota durante el golpeo paralelo de derecha en tenis Descargar Francesc Corbi Soler

    2008-09-01

    Full Text Available En el presente trabajo, a través de una visión funcional y estructural, nos adentramos en el estudio de la biomecánica del pie. Para ello, se realiza un profundo análisis de sus características, de los diferentes factores que influyen en la aparición de las lesiones, de los diversos tipos de patrones de presión plantar y de la relación existente entre el pie y la optimización del rendimiento. Por otro lado, el tenis es uno del los deportes en el que, dadas sus particulares características, el pie adquiere un especial protagonismo, tanto desde un punto de vista lesional como de rendimiento, especialmente durante la realización de los distintos tipos de golpeos y desplazamientos. Conscientes de su importancia, en la primera parte de este estudio se analizaron cuales fueron las variables, relacionadas con la cinemática del pie, que mejor contribuían a explicar la variabilidad en la velocidad máxima de la bola, tras la realización del golpeo paralelo de derecha (GPD. A continuación, se compararon los patrones de presión plantar registrados durante la realización del GPD con los patrones registrados durante marcha. La muestra analizada estuvo formada por 31 tenistas de nivel nacional e internacional. De los diversos instrumentos utilizados, debemos destacar la utilización del sistema de análisis “Tenis Sincro”. Diseñado y fabricado especialmente para este estudio, nos permitió sincronizar los diversos instrumentos utilizados en la realización de este estudio: tres células fotoeléctricas, una máquina lanzapelotas, unas plantillas instrumentadas para el registro de las presiones plantares, un micrófono, dos videocámaras y un radar. Para el posterior análisis estadístico, se utilizó el paquete estadístico R. Mediante la aplicación de modelos de análisis mixto, se constató que la interacción que mejor contribuyó a explicar la velocidad máxima de la bola tras el golpeo fue la que interrelacionaba a la velocidad de

  18. Control y presión al comer en madres de preescolares costarricenses, y su relación con la clase social, la escolaridad, las prácticas de alimentación temprana y el índice de masa corporal de sus hijos e hijas

    Directory of Open Access Journals (Sweden)

    Alejandro Chacón-Villalobos

    2011-01-01

    Full Text Available El objetivo planteado en este trabajo fue el de caracterizar la presion y el control al comer que ejercen madres de preescolares costarricenses de clase alta y baja, evaluando relaciones con el IMC de sus hijos, el tipo de lactancia, la ablactacion, la escolaridad de la madre y su dedicacion al hogar. Para ello se solicito a 102 madres de clase alta y 121 de clase baja completar una encuesta validada (alpha de Cronbach de 0,7 basada en escalas de Likert, para cuantificar, ademas de la informacion general requerida, los niveles de control y presion. Adicionalmente, se determino el IMC segun genero de sus hijos preescolares (102 ninos de clase alta y 103 de clase baja. Para el estudio de los datos se utilizaron pruebas de t-Student y analisis de varianza, asi como correlaciones y evaluaciones de chi cuadrado. Se establecio una tendencia al sobrepeso en ambos sexos en la clase alta, la cual contrasta con las ninas pobres quienes tienden al bajo peso. Se evidencio una mayor frecuencia de trabajo fuera del hogar en la clase baja (p=0,008, siendo la introduccion de alimentos solidos mas temprana (p=0,04. La leche materna fue la opcion mas empleada en ambas clases sociales para el neonato. Ambas clases mostraron "control" y "presión" altas, especialmente entre las madres de clase social baja que trabajan fuera del hogar (p=0,0001. Ambos parametros correlacionan de manera positiva moderada (r=0,44; alpha=0,05. La correlación es mas fuerte entre la clase alta (r=0,54, sobre todo en las niñas (r=0,6.

  19. Desenvolvimento de um simulador numérico empregando o método Smoothed Particle Hydrodynamics para a resolução de escoamentos incompressíveis. Implementação computacional em paralelo (CUDA)

    OpenAIRE

    Marciana Lima Góes

    2012-01-01

    Neste trabalho, foi desenvolvido um simulador numérico baseado no método livre de malhas Smoothed Particle Hydrodynamics (SPH) para a resolução de escoamentos de fluidos newtonianos incompressíveis. Diferentemente da maioria das versões existentes deste método, o código numérico faz uso de uma técnica iterativa na determinação do campo de pressões. Este procedimento emprega a forma diferencial de uma equação de estado para um fluido compressível e a equação da continuidade a ...

  20. La política monetaria de la reserva federal y del Banco de la República: entre la ortodoxia y las presiones inflacionarias. Asimetrías en la transmisión de la política monetaria

    Directory of Open Access Journals (Sweden)

    Romel Rodríguez Hernández

    2008-07-01

    Full Text Available En el presente trabajo se compara la política monetaria del Banco Central en Colombia (BR que sigue una política de inflación objetivo y la efectuada por la Reserva Federal de Estados Unidos (FED, analizando sus efectos a partir de choques generados por variaciones en la tasa de interés, principal instrumento de política, sobre la inflación, el crédito y los mercados financieros, a partir de un VAR Estructural. De los resultados se concluye que la transmisión de política monetaria es más rápida en el caso de Estados Unidos con relación al caso colombiano donde el efecto de política monetaria opera con mayor rezago y produciendo una mayor volatilidad sobre la demanda de crédito y las tasas de los títulos de deuda del Gobierno, principal instrumento de renta fija. Por tanto, el control de las presiones inflacionarias de demanda es más complejo en el caso colombiano, requiriendo del BR una postura menos acomodaticia respecto a la FED para conseguir una estabilidad de precios a largo plazo, la cual, en el largo plazo, en una economía abierta, está sujeta al desarrollo del mercado de crédito y de capitales, no obstante, el esquema de política adoptado por el Banco Central.

  1. Central catheter dressing in a simulator: the effects of tutor's assistance or self-learning tutorial Parche de catéter central en simulador: efecto de la presencia del tutor o del aprendizaje auto-instruccional Curativo de cateter central em simulador: efeito da presença do tutor ou da aprendizagem autoinstrucional

    Directory of Open Access Journals (Sweden)

    Milene Thaís Marmol

    2012-12-01

    Full Text Available AIMS: to compare the performance of undergraduate students concerning semi-implanted central venous catheter dressing in a simulator, with the assistance of a tutor or of a self-learning tutorial. METHOD: Randomized controlled trial. The sample consisted of 35 undergraduate nursing students, who were divided into two groups after attending an open dialogue presentation class and watching a video. One group undertook the procedure practice with a tutor and the other with the assistance of a self-learning tutorial. RESULTS: in relation to cognitive knowledge, the two groups had lower performance in the pre-test than in the post-test. The group that received assistance from a tutor performed better in the practical assessment. CONCLUSION: the simulation undertaken with the assistance of a tutor showed to be the most effective learning strategy when compared to the simulation using a self-learning tutorial. Advances in nursing simulation technology are of upmost importance and the role of the tutor in the learning process should be highlighted, taking into consideration the role this professional plays in knowledge acquisition and in the development of critical-reflexive thoughts and attitudes. (ClinicalTrials.gov Identifier: NCT 01614314.OBJETIVO: comparar el desempeño de graduandos en la realización del parche del catéter venoso central semi-implantado, en simulador, con el auxilio del tutor o de un guía auto-instruccional. MÉTODO: estudio experimental controlado hecho aleatorio. La muestra fue compuesta por 35 alumnos de Graduación en Enfermería que fueron asignados en dos grupos después de asistir a una clase expositiva dialogada y a un vídeo. Un grupo realizó el entrenamiento del procedimiento con el tutor y el otro con el auxilio de un guía auto- instruccional. RESULTADOS: con relación al conocimiento cognoscitivo, los dos grupos presentaron desempeño menor en la pre-prueba comparada al pos-prueba. El grupo con presencia del tutor

  2. Analysis of production data and fluid thermodynamic conditions in wells of Los Humeros, Pue; Analisis de datos de produccion y condiciones termodinamicas del fluido de alimentacion de pozos de Los Humeros, Pue.

    Energy Technology Data Exchange (ETDEWEB)

    Arellano Gomez, Victor Manuel; Aragon Aguilar, Alfonso; Barragan Reyes, Rosa Maria [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico); Flores Armenta, Magaly; Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico); Tovar Aguado, Rigoberto [Comision Federal de Electricidad (Mexico)]. E-mail: vag@iie.org.mx

    2008-07-15

    Production data from 22 wells of the Los Humeros geothermal field in Puebla, Mexico, were analyzed to estimate the thermodynamic conditions (pressure and enthalpy) of the bottom-hole fluids entering the wells and the changes to the fluids after exploitation. The bottom-well conditions were obtained by simulating the production histories of the wells, using the WELLSIM numerical simulator. The reservoir temperature was estimated by the FT-HSH2 gas-equilibrium method, which provided values matching very well the measured-well temperatures under static conditions. To estimate the rates of change of the well-bottom thermodynamic variables-pressure and enthalpy-the linear and the harmonic methods were used. According to these models, overall results indicated pressure-decline rates of between 0.92 (linear method) and 1.03 bar/year (harmonic method), average enthalpy increases of between 9.4 (linear) and 10.3 (harmonic) kJ/kg/year, and a temperature increase of about 1.2 degrees Celsius/year (linear method). These rates of parameter change were considered moderate, likely due to recharge from the deeper reservoir. The wells showing higher-pressure declines were H-35, H-1, and H-1D; and the wells showing higher-enthalpy increases were H-1D, H-3D, and H-19D. Most wells showed temperature increases, although a temperature decrease was noticed in wells H-16R and H-36, probably due to mechanical damage in the wells or weak communication with the deeper reservoir. [Spanish] Se realizo un analisis de los datos de produccion de 22 pozos del campo geotermico de Los Humeros, Pue., Mexico, con objeto de estimar las condiciones termodinamicas (presion y entalpia) de sus fluidos de alimentacion y su evolucion en el tiempo como respuesta a la explotacion. Las condiciones a fondo de pozo se obtuvieron al simular las historias de produccion de los pozos mediante el simulador numerico WELLSIM. La temperatura de fondo se estimo mediante el metodo de equilibrio gaseoso FT-HSH2 ya que fue

  3. Experiences in the use of an electronic tool to measure pressure, temperature and spinner logs in the Mexican geothermal fields; Experiencias en el uso de sondas electronicas de presion, temperatura y flujo en campos geotermicos de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly; Jaimes Maldonado, Guillermo [Gerencia de Proyectos Geotermoelectricos, Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    1999-08-01

    In this article are exposed the results of an electronic tool to measure pressure-temperature and spinner profiles in the geothermal wells of Mexico, utilized in order to identify unobservable phenomena with traditional Kuster type pressure and temperature logs. Some examples of the applications are the identifications of production zones, interaction from between two or more zones of contribution under several conditions of operation, casing damages and apparition of sink flow intervals into the formation in producer wells. It is also presented the quantitative method utilized to calculate the masic contribution of the intervals of interest. [Spanish] En este articulo se exponen los resultados obtenidos mediante el uso de una sonda electronica para la medicion de presion-temperatura y flujo en los pozos geotermicos de Mexico, utilizada para identificar fenomenos que no son observables con las mediciones tradicionales tipo Kuster de presion y temperatura. Se ejemplifican algunas de las aplicaciones hechas, tales como la identificacion de zonas de produccion, forma de interaccion entre dos o mas zonas de aporte bajo diferentes condiciones de operacion, roturas en tuberias y aparicion de zonas ladronas en pozos. Se presenta brevemente el metodo cuantitativo utilizado para calcular el aporte masico de las intervalos de interes.

  4. Pressure fluctuations on the bed of surge tank at the H.P. Zimapan, Hgo., with different arrangements studied on hydraulic model, with the lowest operation conditions; Fluctuaciones de presion en la base del pozo de oscilacion del P.H. Zimapan Hgo., con diferentes arreglos estudiados en modelo hidraulico ante las condiciones minimas de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Marengo Mogollon, H. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: humberto.marengo@cfe.gob.mx; Ochoa Alvarez, F.J.; Cortes Cortes, C. [Comision Federal de Electricidad (Mexico)]. E-mail: federico.ochoa@cfe.gob.mx; carlos.cortes01@cfe.gob.mx

    2009-10-15

    In this paper, the pressure fluctuations of the surge tank in the Zimapan Hydroelectric Project are compared in a hydraulic model. The shaft is located lateral, over the conduction tunnel and in the simple form (permitting the tunnel entering the shaft); with and without orifice plates taking into account the demand and supply condition of energy with the minimum level of water of the conduction. It was determined the hydraulic efficiency and it was found that it was the best constructive option. [Spanish] En este articulo se comparan las fluctuaciones de presion en el pozo de oscilacion del P.H. Zimapan, Hgo., Mexico las cuales fueron estudiadas en modelo hidraulico al considerar dicho pozo ubicado en diferentes posiciones; lateralmente y sobre el eje de la conduccion; pozo simple y con tuberia de conexion; con y sin placa de orificio, para maniobras de rechazo y demanda de carga de las turbinas de generacion con el nivel del agua correspondiente al NAMINO. Se determino la eficiencia hidraulica comparandola con las otras opciones encontrandose que la mejor opcion para el funcionamiento hidraulico es el pozo lateral, que ademas permite optimizar el procedimiento constructivo.

  5. Solar still with ejector: Experimental phase; Destilador solar con eyector: Fase experimental

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Juan R; Lopez, Raymundo; Diaz, Alen; Lara, Araceli; Lizardi, Arturo [Universidad Autonoma Metropolitana Azcapotzalco, Mexico, D.F. (Mexico)

    2000-07-01

    temperatura adecuada se doto al simulador de una resistencia de 500 W. El tirante se selecciono de 5 cm. Para que la resistencia de calefaccion pudiera estar completamente sumergida. La caseta se construyo con paredes de acrilico y la parte superior por dos paneles de vidrio de 3 mm de espesor formando un angulo de 20 grados respecto de la horizontal de modo que se ajuste a la latitud del lugar del ensayo, la Ciudad de Mexico. El eyector tiene una longitud de 25 cm y una seccion transversal de 19 mm; y se monta a lo largo de la caseta cuidando que se posicion quede ligeramente por encima del tirante. El fluido motor, en este caso agua, se hace circular por el eyector por medio de un deposito presurizado con aire. El gasto se regula con una valvula de aguja y cada carga del tanque permite una operacion de 60 min. La presion en el tanque externo al eyector (deposito presurizado) permite desarrollar una carga de 40 m columna de agua. El agua en el colector se lleva a una temperatura uniforme y constante de 40 grados Celsius, se espera que todo el medio del eyector alcance la temperatura senalada y se hace circular agua a 20 grados Celsius por el eyector. La operacion del simulador es intermitente. Los resultados se presentan en una tabla y muestran que el funcionamiento del destilador asistido por el eyector puede ser mejorado en forma notable.

  6. Acero de alto silicio producido por inmersión en Al-Si y recocido de difusión

    Directory of Open Access Journals (Sweden)

    Ros-Yáñez, Tanya

    2000-10-01

    Full Text Available It is difficult to process steel sheet with a high Si content (>3.5%Si, mainly because of its brittleness and the appearance of cracks during rolling and oxidation. However, there is a market for this steel in electrical applications because of the favourable influence of Si on magnetostriction and electrical resistivity. As an alternative process, 3% Si-steel substrates were coated with hypereutectic Al-Si-alloys in a "hot-dip simulator" using different preheating and dipping times. The obtained layers were characterised by SEM and EDS analysis. Diffusion annealing experiments were performed to obtain sufficient amount of Si in the steel. It was observed that:

    • intermetallic phases appear in the coating layers as according to the ternary Fe-Si-Al diagram
    • with a double dipping primary silicon crystals are formed in the surface layer
    • the ordered DO3 structure is present if the dipping and/or diffusion time is long enough
    • homogeneous silicon gradients in the whole substrate thickness have not yet been achieved
    • theoretic calculations show that Si-gradient, also have beneficial effects on magnetic behaviour


    Es difícil procesar aceros eléctricos de alto contenido en silicio (>3,5 % Si. Esto se debe principalmente, a problemas de fragilidad, aparición de grietas durante la laminación y oxidación. Sin embargo, existe un importante mercado para este tipo de acero en aplicaciones eléctricas debido a la favorable influencia que ejerce el Si sobre la magnetoestricción, las pérdidas eléctricas y la resistividad eléctrica. Como proceso alternativo, se sumergieron substratos de acero con 3 % de silicio en una aleación hipereutéctica Al-25 % Si, en un simulador de recubrimiento por inmersión en caliente. En los ensayos se utilizaron diferentes tiempos de precalentamiento y de inmersión. En la segunda fase de la investigación se llevaron a cabo recocidos de difusión en el

  7. Detection of the high vibration origin in the body of an electrical generator driven by steam turbine applying diagnostic techniques; Deteccion del origen de alta vibracion en el cuerpo de un generador electrico accionado por turbinas de vapor aplicando tecnicas de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Bravo, Fernando (Mexico)

    2007-11-15

    One of the problems that electric generators present is the high vibration due to causes that can go from simple mechanical unbalance, misalignment, mechanical relaxation, resonance or some other interaction that can influence in the system. In this document is presented the vibration analysis of an electric generator with a capacity of 350 MW, driven by a steam turbine composed of three stages (high pressure, intermediate pressure and low pressure) connected to the electric generator through a rigid connection. [Spanish] Uno de los problemas que se presentan en los generadores electricos es la alta vibracion debida a causas que pueden ir desde un simple desbalance mecanico, desalineamiento, aflojamiento mecanico, resonancia o alguna otra interaccion que pueda influir en el sistema. Se presenta en este documento el analisis de vibracion de un generador electrico con una capacidad de 350 MW, impulsado por una turbina de vapor compuesta de tres etapas (alta presion, presion intermedia y baja presion) acopladas al generador electrico a traves de un acoplamiento rigido.

  8. Influência de cultivares de arroz e épocas da adubação nitrogenada nas relações de interferência da cultura com cultivar simulador de infestação de arroz-vermelho Influence of rice cultivars and nitrogen fertilizer timing on the interference relationships between the crop and cultivar simulating red rice infestation

    Directory of Open Access Journals (Sweden)

    D. Agostinetto

    2004-06-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de cultivares de arroz irrigado e de épocas de adubação nitrogenada durante o ciclo da cultura sobre a habilidade competitiva do cereal em relação ao cultivar EEA 406, usado como simulador da planta daninha arrozvermelho. Para isso, conduziu-se experimento em campo, na estação de crescimento 2001/02. Os tratamentos, dispostos em esquema fatorial, constaram de cultivares de arroz (BRS-38 Ligeirinho, IRGA 417 e BR-IRGA 409, épocas de aplicação do nitrogênio (N (100% do N na semeadura, 50% do N na semeadura mais 50% no início da diferenciação da panícula (IDP, 100% no IDP e testemunha sem o adubo e populações do cultivar simulador do arroz-vermelho. Para relacionar as perdas de produtividade de grãos de arroz com populações do cultivar simulador, utilizou-se o modelo de regressão da hipérbole retangular, ajustado de modo independente para os fatores estudados. Verificou-se que a época de aplicação do N influenciou na habilidade competitiva dos cultivares de arroz. Cultivares de ciclo muito curto e curto apresentaram maior habilidade competitiva com o cultivar simulador, quando a adubação foi realizada na semeadura, enquanto o cultivar de ciclo médio se beneficiou do fracionamento da adubação na semeadura e no IDP.The objective of this study was to evaluate the effects of flooded rice cultivars and timings of nitrogen fertilizer application during the crop cycle on the competitive ability of this cereal in relation to EEA 406 cultivar, used as a mimicker of red rice. Thus, a field experiment was carried out during the 2001/02 growing season. The treatments were arranged in a factorial design,comprising the rice cultivars (BRS-38 Ligeirinho, IRGA 417, and BR-IRGA 409, nitrogen (N application timings (100% at sowing, 50% at sowing plus 50% at the beginning of panicle differentiation (BPD, 100% at BPD, and check without fertilizer, and densities of the mimicker cultivar. In

  9. Análisis Cinemático y Control Articular Aplicado a Simulador de Movimiento de Estructura Paralela

    Directory of Open Access Journals (Sweden)

    Orlando Urquijo Pascual

    2011-11-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} En este artículo se realiza el modelado cinemático, y control articular de un robot de estructura paralela de 3 grados de libertad que se utiliza como simulador de movimiento. Dicho robot es accionado por cilindros neumáticos. El modelo basado en relaciones cinemáticas se valida mediante técnicas de simulación y posteriormente se emplea para generar los valores deseados de las variables articulares, implementándose con ello un esquema de control de posición en el espacio articular. Se muestran los resultados obtenidos de la simulación y se comprueban los mismos con las pruebas experimentales efectuadas, demostrándose la validez de las ecuaciones del modelo y el comportamiento adecuado del sistema robótico bajo el esquema de control de posición propuesto.

  10. Structural integrity assessment of a pressure container component. Design and service code implementation. Case studies; Evaluacion de la integridad estructural de un componente contenedor de presion. Aplicacion de los codigos para el disenio y servicio. Estudio de casos

    Energy Technology Data Exchange (ETDEWEB)

    Sanzi, H C [Universidad Tecnologica Nacional, Buenos Aires (Argentina)

    2006-07-01

    In the present work, the most important results of the local stresses occurred in the cracked pipes with a axial through-wall crack (outer), produced during operation of a Petrochemical Plant, using finite elements method, are presented. As requested, the component has been verified based 3D FE plastic analysis, under the postulated failure loading, assuring with this method a high degree of accuracy in the results. Codes used by Design and Service, as ASME Section VIII Div. 2 and API 579, have been used in the analysis. (author) [Spanish] La correcta evaluacion de la integridad estructural de componentes contenedores de presion y canierias requiere del conocimiento y la participacion de especialistas en 'Stress Analysis' y materiales e inspectores. En la actualidad, las tecnicas avanzadas de analisis, que incluyen un detallado 'Stress Analysis', a partir de la utilizacion del metodo de elementos finitos y la mecanica de Fractura, junto con el conocimiento del comportamiento de los materiales y la capacidad para detectar fisuras o discontinuidades - tales como los ensayos no destructivos y la emision acustica - permiten garantizar la seguridad de los componentes a lo largo de su vida util. En este camino los codigos de aplicacion, tanto en el disenio como en el servicio, son utilizados para llevar a cabo un estudio de integridad. En este trabajo se presenta un procedimiento de calculo para evaluar la integridad estructural de un componte contenedor de presion que posee una falla superficial no pasante, en donde se aplica el Codigo API 579, utilizando el metodo de elementos finitos y la mecanica de fractura. (autor)

  11. Response to exploitation (1982-2002) of the Los Azufres, Michoacan (Mexico) geothermal field. Part II: South Zone; Respuesta a la explotacion (1982-2003) del yacimiento geotermico de Los Azufres, Michoacan (Mexico). Parte II: Zona Sur

    Energy Technology Data Exchange (ETDEWEB)

    Arellano G, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico); Torres R, Marco Antonio [Comision Federal de Electricidad, Morelia, Michoacan (Mexico); Barragan R, Rosa Maria [Instituto de Investigaciones Electricas, Cuernavaca, Morelos, (Mexico); Sandoval M, Fernando [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    2005-06-01

    The paper describes the thermodynamic evolution of fluids in the Los Azufres geothermal field's southern zone reservoir, as a response to exploitation from 1982 to 2002. Thermodynamic conditions for the reservoir fluids were estimated with production data using the WELFLO heat-and-flow well simulator. In the southern zone, initial fluid thermodynamic conditions indicated that compressed liquid, two-phase fluids and vapor occurred in the reservoir, depending on the well depths. The fist response to exploitation consisted in a pressure drop an enthalpy increase. For the long term, the following patterns have been identified: pressure and mass flow-rate drop, boiling, cooling, vapor production and in some wells affected by injection an increase in both pressure and mass flow rate. The isotopic results of well fluids in the southern zone showed the occurrence of two processes. The first, with a positive slope, indicates a mixing of reservoir and injection fluids and mainly affects wells Az-2, Az-16, Az-33, Az-36 and Az-46. The second, with a negative slope, results from the original processes of reservoir steam separation and partial condensation. [Spanish] En este trabajo se presenta un estudio sobre la evolucion termodinamica de los fluidos de la zona sur del yacimiento de Los Azufres, como respuesta a la extraccion e inyeccion de fluidos, desde el inicio de su explotacion en 1982 hasta el ano 2002. Las condiciones termodinamicas de los fluidos del yacimiento se estimaron mediante el simulador de flujo de fluidos y calor en pozos WELFLO, a partir de datos de produccion. Las condiciones termodinamicas iniciales de los fluidos de la zona sur, indicaron la existencia de liquido comprimido, dos fases con liquido dominante y dos fases con vapor dominante, dependiendo de la profundidad de los pozos. La respuesta inicial de la zona sur a la explotacion consistio en una disminucion de la presion y un aumento en la entalpia mientras que a mas largo plazo se han observado

  12. Modelo Biomecánico de una Prótesis de Pierna

    Directory of Open Access Journals (Sweden)

    A.M. Diego Bravo

    2014-10-01

    Full Text Available Resumen: En este trabajo se presenta el modelo biomecánico de una prótesis de pierna. Con el objetivo de estudiar el cambio de velocidad en la unión prótesis-muñón al momento del impacto del pie con el suelo, está se modeló como un sistema resorte-amortiguador, per- mitiendo evidenciar la necesidad de construir la unión muñón-prótesis con dispositivos de impedancia mecánica variable. Adema's se desarrolló un simulador con el objetivo de hacer representaciones virtuales de un paciente con prótesis. Para ello se modeló al paciente como un robot b́ıpedo planar, el simulador permite estudiar el efecto de las fuerzas de impacto con el suelo de la unión prótesis-muñón como una etapa anterior a la implementación real de la misma. Palabras clave: Marcha humana, Modelo biomecánico, prótesis, simulación.

  13. Immunohistochemical detection of the latent nuclear antigen-1 of the human herpesvirus type 8 to differentiate cutaneous epidemic Kaposi sarcoma and its histological simulators Detecção imuno-histoquímica do antígeno nuclear latente-1 do herpesvirus tipo 8 para diferenciar o sarcoma de Kaposi epidêmico cutâneo de seus simuladores histológicos

    Directory of Open Access Journals (Sweden)

    Patricia Fonseca Pereira

    2013-04-01

    Full Text Available Kaposi's sarcoma is the most common neoplasia diagnosed in AIDS patients and the expression of the human herpesvirus-8 (HHV-8 latent nuclear antigen-1 has been useful for its histological diagnosis. The aim of this study is to confirm that immunohistochemistry is a valuable tool for differentiating KS from its simulators in skin biopsies of HIV patients. Immunohistochemical and histological analyses were performed in 49 Kaposi's sarcoma skin biopsies and 60 of its histological simulators. Positivity was present in the 49 Kaposi's sarcoma skin biopsies and no staining was observed in the 60 simulators analyzed, resulting in sensibility and specificity of 100%. HHV-8 immunohistochemical detection is an effective tool for diagnosing Kaposi's sarcoma, especially in early lesions in which neoplastic features are not evident. It also contributes to its histological differential diagnosis.O sarcoma de Kaposi é a neoplasia mais diagnosticada em pacientes com SIDA e a expressão do antígeno nuclear latente-1 do herpesvírus humano tipo-8 (HHV-8 tem se mostrado útil no seu diagnóstico histológico. O objetivo deste estudo é confirmar que o método imuno-histoquímico é uma ferramenta útil para diferenciar o sarcoma de Kaposi cutâneo de seus simuladores histológicos em pacientes HIV positivos. Análise histológica e imuno-histoquímica foram realizadas em 49 casos de sarcoma de Kaposi cutâneo e 60 casos de seus simuladores histológicos. Positividade à imuno-histoquímica para o antígeno nuclear latente 1 do HHV-8 foi observada nos 49 casos de sarcoma de Kaposi e nenhuma reação foi detectada nos 60 simuladores analisados, resultando em 100% de sensibilidade e especificidade. A detecção do HHV-8 por imuno-histoquímica é uma ferramenta útil para o diagnóstico de sarcoma de Kaposi, especialmente na lesão inicial cujo caráter neoplásico não é evidente, e contribui para seu diagnóstico diferencial histológico.

  14. Seismic pressure effect on retaining walls; Presiones generadas por sismo en muros de retencion

    Energy Technology Data Exchange (ETDEWEB)

    Bonola, Isaac; Aviles, Javier [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

    2006-04-15

    Retaining walls are auxiliary works used in different hydraulic structures. In seismically active areas, the dynamic pressures generated by the backfill must be appropriately evaluated at the design stage. Currently, a number of methods for estimating the seismic response of this type of works are available; however, most of them are simplified and not all the parameters involved have been examined. In this paper, a hybrid boundary and finite element method is presented for gravity walls in which the backfill can be represented by a horizontally layered medium. The effect of lateral extension of the backfill can be included in the model by introducing a vertical boundary coupling the movement of the backfill with that of the surrounding soil. The wave propagation analysis in the layered medium is carried out for both horizontal and vertical harmonic excitation; the latter excitation may cause important responses under certain situations. To illustrate the applicability of the proposed method, results for two numerical examples are presented: one for dry backfill and other for saturated backfill, considering in both cases the variations of dynamic properties of the soil with the depth. [Spanish] Los muros de retencion son estructuras auxiliares utilizadas en distintas obras hidraulicas. En zonas sismicas, las presiones dinamicas generadas por el relleno deben evaluarse adecuadamente en la etapa de diseno. Actualmente existen numerosos metodos para estimar la respuesta sismica de este tipo de estructuras; sin embargo, la mayoria de ellos son simplificados y no todos los parametros involucrados han sido examinados. En este trabajo se presenta un metodo hibrido de frontera y elemento finito para muros de gravedad en el que el relleno puede representarse por un medio estratificado horizontalmente. En el modelo puede incluirse el efecto de la extension lateral del relleno, introduciendo una frontera vertical que acopla el movimiento del relleno con el del suelo

  15. Dynamic analysis of the condensate and of the feed water in the Laguna Verde nuclear power station; Analisis dinamico del sistema de condensado y agua de alimentacion de la nucleoelectrica de Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Muth, Javier; Sandoval Pena, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This article shows a non-lineal mathematical model for the condensate, and feed water systems and for feed water heater drains at the Laguna Verde Nuclear Power Station for its simulation in real time. The model allows the calculation of flows and pressures in all the piping system and equipment that integrate the systems. It was obtained by using the force unbalance in the fluid concept and is capable of reproducing its dynamic behavior through variations induced by the different operation modes and more common failures. The final model objective is to form part of the Laguna Verde simulator that will be used for operator training of this Nuclear Power Plant. [Espanol] En este articulo se muestra un modelo matematico no lineal de los sistemas de condensado, agua de alimentacion y drenes de calentadores de la central nuclear de Laguna Verde para su simulacion en tiempo real. El modelo permite calcular los flujos y las presiones en toda la red de tuberias y equipos que integran los sistemas. Se obtuvo utilizando el concepto de desbalance de fuerzas en el fluido, y es capaz de reproducir su comportamiento dinamico ante variaciones inducidas por los diversos modos de operacion y fallas mas comunes. El objetivo final del modelo es formar parte del simulador de Laguna Verde que se empleara para el adiestramiento de los operadores de dicha central nuclear.

  16. Non-Destructive Testing in Reactor Pressure-Vessel Fabrication; Essais non Destructifs dans la Fabrication des Caissons Etanches de Reacteurs; Nedestruktivnoe ispytanie pri izgotovlenii reaktornykh bakov vysokogo davleniya; Ensayo no Destructivo Durante la Fabricacion de Recipientes de Presion para Reactores

    Energy Technology Data Exchange (ETDEWEB)

    McGonnagle, W. J. [Fluids Dynamics Research, Iit Research Institute, Chicago, IL (United States)

    1965-09-15

    las tecnicas especializadas propias del ensayo no destructivo de recipientes de presion y sus componentes. Se da una idea general de las normas y especificaciones pertinentes, tales como el Codigo de Calderas y Recipientes de Presion, de la American Society for Mechanical Engineers, y de otras organizaciones de supervision. Se analiza la manera en que el ensayo no destructivo puede contribuir a satisfacer las especificaciones y requerimientos de esas diversas organizaciones, y tambien la conveniencia y posibilidad de aplicar las normas usadas en tales casos. Se sugieren criterios realistas, pero apropiados, de aceptacion y rechazo. Se esboza un procedimiento que permitira y ayudara al personal dedicado a estos ensayos, a cumplir adecuadamente sus funciones en el momento apropiado del ciclo de fabricacion. Se discute la relacion existente entre el grupo de ensayos no destructivos y los demas grupos que intervienen en la fabricacion de los recipientes de presion. (author) [Russian] Cel' raboty zakljuchaetsja v tom, chtoby dat' kratkoe opisanie programmy kontrolja kachestva konstrukcii i izgotovlenija reaktornogo baka vysokogo davlenija, kotoryj udovletvorjaet vsem trebovanijam s tochki zrenija jadernogo processa i bezopasnosti jekspluatacii, a takzhe pokazat' znachenie nedestruktivnogo ispytanija v dostizhenii jetoj celi. Defekty materialov, komponentov i sborki pokazali, chto nashi nyneshnie metody izgotovlenija javljajutsja nedostatochnymi dlja obespechenija mnogokratnoj nadezhnosti kriticheskih komponentov. Treshhiny i neodnorodnost' v strukture materiala byvajut dazhe togda, kogda ispol'zujutsja nailuchshie processy i dolzhnym obrazom kontroliruemye metody i procedury. Neobhodima bolee sovershennaja kompleksnaja programma nedestruktivnyh ispytanij dlja togo, chtoby obespechit' takoj uroven' kachestva, kotoryj trebuetsja dlja reaktornogo baka vysokogo davlenija. Izgotoviteli takih bakov ispol'zujut sledujushhie metody nedestruktivnyh ispytanij: vizual

  17. Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

  18. Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

  19. Resistencia al desgaste de recubrimientos de bronce al aluminio producidos con técnica de proyección térmica//Wear resistance of aluminum bronze coatings produced by thermal spray

    Directory of Open Access Journals (Sweden)

    Dayan Carolina Cárdenas-Feria

    2015-09-01

    Full Text Available Se estudió la resistencia al desgaste adhesivo de recubrimientos de bronce al aluminio depositados con la técnica de proyección térmica por llama sobre bronce fosforado SAE 62. Los recubrimientos fueron fabricados variando las presiones parciales de los gases de combustión, oxígeno y acetileno. El material utilizado fue caracterizado estructuralmente mediante difracción de rayosX (X-ray diffraction, XRD y el estudio morfológico mediante microscopía electrónica de barrido (Scanning electron microscopy, SEM. La resistencia al desgaste adhesivo de los recubrimientos se determinó por medio del ensayo de bola sobre disco, utilizando como bola una esférica de acero 100Cr6. Los resultados obtenidos permiten establecer que los recubrimientos proyectados con una presión de oxigeno de 78 psi y una presión de acetileno de 8 psi presentan la mejor resistencia al desgaste en comparación a los tratamientos producidos. El modo de falla de desgaste en los recubrimientos producidos es discutido en esta investigación.Palabras clave: desgaste abrasivo y adhesivo,  proyección térmica,  recubrimientos.______________________________________________________________________________AbstractWe studied the adhesive wear resistance of aluminum bronze coatings deposited by thermal spray on phosphor bronze SAE 62 substrates. The coatings were deposited by varying the partial pressures of the combustion gases: oxygen and acetylene. The structural characterization was made through X-ray diffraction (XRD and the morphological analysis was performed by scanning electron microscopy (SEM. The adhesive wear resistance of the coatings was determined by the bole on disc test using a spherical ball made of steel 100Cr6 and with a diameter of 6 mm. The results obtained show that the coating projected with an oxygen pressure of 78 psi and an acetylene pressure of 8 psi have the better wear resistance compared with the substrate and the others treatments deposited

  20. ¿Conoce usted de la barodontología?

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo González García

    2002-01-01

    Full Text Available Con el fin de conocer de cerca una situacion fisiologica producida por los cambios en Ia presion atmosferica que ha sido poco desarrollada por Ia medicina de aviacion, debido a su baja incidencia de casos, queremos llegar a usted para que conozca basicamente el proceso de la BARODONTALGIA, cuando le puede suceder y que debe hacer en caso de manifestarla; al igual que informar al personal profesional en salud oral sobre esta sintomatologfa y sus manifestaciones en cavidad oral.

  1. ANÁLISIS DE SENSIBILIDAD POR SIMULACIÓN DEL PROCESO DE DESHIDRATACIÓN DE UNA PLANTA DE ACONDICIONAMIENTO DE GAS NATURAL

    Directory of Open Access Journals (Sweden)

    Eleonora Erdmann

    2012-01-01

    Full Text Available Este trabajo describe el desarrollo de un simulador estacionario para los sectores de deshidratación y estabilización de una planta de tratamiento de gas natural. El simulador fue implementado empleando el simulador comercial ASPEN HYSYS®. El gas considerado en la simulación es un gas típico proveniente de yacimientos de la provincia de Salta (Argentina. La configuración de la planta y las condiciones de operación adoptadas para la simulación son las generalmente empleadas en el tratamiento de gas natural en Salta. Con el simulador desarrollado, se llevó a cabo un estudio de sensibilidad paramétrica de las principales variables operativas del proceso. La simulación realizada permite visualizar el proceso de deshidratación, y realizar un análisis de su comportamiento en función de las variables operativas críticas: concentración de la solución de TEG (70% p – 99% p y temperatura del rehervidor (200 – 375 oF.

  2. Control system design for the deethanizer absorber tower pressure in the light end unit of the Nico Lopez refinery; Diseno del sistema de control para la presion en la torre absorvedora deetanizadora de la unidad de finales ligeros de la refineria Nico Lopez

    Energy Technology Data Exchange (ETDEWEB)

    Morales Corral, Camilo [Refineria Nico Lopez, Ciudad Habana (Cuba)]. E-mail: Camilo.morales@refhab.cupet.cu; Pedre Mendoza, Isabel [DAISA, Ciudad Habana (Cuba)]. E-mail: Isabel@daisa.copextel.com.cu; Garcini Leal, Hector J. [Instituto Superior Politecnico Jose A. Echeverria, La Habana (Cuba)]. E-mail: garcini,novi@electrica.cujae.edu.cu; Fernandez, Luis M. [Instituto de Cibernetica, Matematica y Fisica, La Habana (Cuba)]. E-mail: luis@icmf.inf.cu; Benitez Gonzalez, Ivon Oristela [Instituto Superior Politecnico Jose A. Echeverria, La Habana (Cuba)

    2010-11-15

    This paper is about pressure feed forward control. It is for an absorber tower of the Light End Unit. This one is in the Havana Oil Refinery. Control loop was designed using identification technic and simulation software. Moreover the design control loop has been validated and his quality has been determined. [Spanish] En el presente trabajo se aborda un control anticipatorio de presion. Fue desarrollado para la torre absorvedora de la Unidad de Finales Ligeros. La cual pertenece a la refineria de La Habana. Fue disenado un lazo de control empleando tecnicas de identificacion y programas de simulacion. Ademas el lazo disenado es validado y se determina su calidad.

  3. Sistema de Alerta al Conductor Basado en Realimentación Vibro-Táctil

    Directory of Open Access Journals (Sweden)

    Emanuel Slawiñski

    2015-01-01

    Full Text Available Resumen: Este trabajo propone el diseño y desarrollo de un sistema de alerta al conductor basado en la realimentación de estimulos vibro- táctiles de fuerza con el objetivo de prevenir accidentes de tránsito. El sistema posee dos agarres vibro-tactiles, los cuales se pueden montar facilmente sobre cualquier tipo de vehículo, y un sistema electrónico basado en un sistema de localización y comunicación inalámbrica entre vehículos, que permite calcular en línea una señal de alerta vibro-táctil para avisar al conductor de una posible situación de peligro en los proximos segundos. Un modelo focalizado en factores humanos es propuesto y utilizado para justificar el uso adecuado de estímulos artificiales. Además se describen, el hardware, la comunicación entre vehículos y software embebido. Finalmente, el sistema es probado en un simulador 3D de carrera de código abierto y también utilizando dos vehículos comunes. Abstract: This paper proposes the design and build of a driver warning system, based on vibro-tactile feedback for preventing accidents through the generation of tactile stimuli. The system has two vibro-tactile grips devices which are easily mounted on the steering wheel of any vehicle and an electronic system based on location sensing as well as inter-vehicles communication, from which a risk level is computed on line in order to warn the driver about dangerous situations and risk zones. A model focalized on human factors is proposed and it is employed to justify the advantages of using artificial stimuli. Besides, the hardware, communication between vehicles and embedded software, are described too. Finally, experiences using the device in a racing car simulator and tests using two ordinary cars are shown. Palabras clave: seguridad, sensores e instrumentos virtuales, automoción, estímulos táctiles de fuerza, prevención de accidentes, Keywords: Safety, sensors and virtual instrument, automotive, vibro

  4. Código de ética para la vida artificial

    OpenAIRE

    Proto Gutierrez, Fernando; Martigani, María Dolores

    2015-01-01

    La enseñanza de las Ciencias de la Salud tienen un componente empírico ineludible: el aprendizaje de habilidades propias de atención y cuidado. Históricamente, y de acuerdo al modelo biomédico, se utilizaron pacientes humanos vivos conforme a la secuencia: ver una vez, hacer una vez y enseñar una vez (Ziv & Berkenstadt, 2008). Con la introducción de simuladores y situaciones simuladas como estrategias, ha cambiado la forma de enseñanza. La uti...

  5. Caminata del robot humanoide RH-2 en la plataforma de simulación OpenHRP

    OpenAIRE

    Torre Doblas, Carlos de

    2010-01-01

    En primer lugar, en este proyecto se trabajará con el simulador OpenHRP3, intentando comprender su funcionamiento interno (carga de archivos, lenguajes, funcionalidades, etc.). También se adaptará el modelo del robot humanoide Rh-2 al entorno del mismo, pudiendo así realizar simulaciones. La verdadera finalidad de este proyecto, y en lo que se ha hecho especial incapié, es simular el robot sosteniendo una caja, validando así las fuerzas que sienten las distintas partes del cuerpo en los momen...

  6. Transfer function modeling of the monthly accumulated rainfall series over the Iberian Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, Vidal L.; Garcia, Jose A.; Serrano, Antonio; De la Cruz Gallego, Maria [Departamento de Fisica, Universidad de Extremadura, Badajoz (Spain)

    2002-10-01

    por los modelos que emplean la presion a nivel del mar, siendo los modelos que emplean la temperatura del agua del mar los que peores resultados proporcionan. Con referencia a la situacion geografica, los modelos ajustados a los observatorios localizados al oeste de la Peninsula dan mejores resultados que los ajustados a los observatorios situados al norte y este de la misma. Asimismo se ha encontrado que existe una region en el Atlantico Norte situada entre los paralelos 0 y 20 N donde la temperatura del agua parece tener alguna influencia sobre las precipitaciones peninsulares. Esta region se traslada hacia el norte cuando se emplean presiones a nivel del mar, a la vez que se intensifica su influencia.

  7. Índice basado en presiones atmosféricas para la detección de efectos de El Niño y la Oscilación del Sur frente a la costa peruana

    Directory of Open Access Journals (Sweden)

    Carlos Quispe

    2008-12-01

    Full Text Available Se analizó el comportamiento de un índice basado en la diferencia de anomalías de presiones atmosféricas entre Darwin y Paita (IDP, como un indicador de los efectos de El Niño y La Niña frente a la costa peruana, en el Norte del Ecosistema de la Corriente de Humboldt (NECH. La variación temporal a escala mensual del IDP tuvo buena correlación (r = 0,68; p<0,01 con el Índice de Oscilación Sur (IOS. Se encontró la máxima correlación cruzada (r = 0,59; p < 0,01 entre el IDP y la AN3.4 con un retraso de -3, lo que permitiría usar el IDP para simular la AN3.4. El comportamiento del IDP obedece a una compleja interacción entre el sistema atmosférico de la región y del Pacifico ecuatorial central.

  8. Simulation of the electric systems of the Laguna Verde nuclear power station; Simulacion de los sistemas electricos de la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Lozano, Saul; Ruiz Ponce, Gerardo E [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-03-01

    In this article, the electric system models of the Laguna Verde Nuclear Power Station (CNLV) simulator, are presented. These models permit the functioning simulation, in the different operation modes of the main generator (Ruiz and Rodriguez 1991a), of the auxiliaries system and of the substation (Ruiz and Rodriguez 1991b), and of the emergency diesel generators system (Ruiz and Rodriguez 1991c). The general characteristics of such systems, considered as the basis to obtain the representative models, which were developed as modules in an independent way to be integrated in the simulator, are also described. [Espanol] En este articulo, se presenta los modelos de los sistemas electricos del simulador de la Central Laguna Verde (CLV). Estos modelos permiten simular el funcionamiento, en los diferentes modos de operacion del generador principal (Ruiz y Rodriguez, 1991a), del sistema de auxiliares y de la subestacion (Ruiz y Rodriguez, 1991b) y del sistema de generadores diesel de emergencia (Ruiz y Rodriguez, 1991c). Asimismo, se describen las caracteristicas generales de tales sistemas, consideradas como la base para obtener los modelos representativos, los cuales fueron desarrollados como modulos en forma independiente para integrarse al simulador.

  9. Initial distribution of pressure and temperature in the geothermal field of Los Humeros, Puebla; Distribucion inicial de presion y temperatura del campo geotermico de Los Humeros, Puebla

    Energy Technology Data Exchange (ETDEWEB)

    Arellano Gomez, Victor M.; Garcia Gutierrez, Alfonso; Barragan Reyes, Rosa Maria; Aragon Aguilar, Alfonso; Pizano, Arturo [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    In order to infer the distributions of non disturbed pressure and temperature of the reservoir fluid, a considerable amount of information originating from several disciplines was analyzed, corresponding to 42 wells of the geothermal field of Los Humeros. On the base of the analyzed data models were developed, in one and two dimensions, of the reservoir in an initial state. The models reveal the existence of at least two reservoirs. The first one and most superficial is located between 1600 and 1025 m.a.s.l. and it is a reservoir of dominant liquid. The pressure profile of this reservoir corresponds to a boiling water column approximately between 300 and 339 Celsius degrees. The second reservoir is located underneath the 850 m.a.s.l. and as far as the collected data, it can be said that it extends at least until the 100 m.a.s.l and it is estimated that it is a reservoir of low liquid saturation. For the wells that are fed from this zone of the field temperatures between 300 and 400 Celsius degrees were estimated. A table of the geology of the subsoil of the region of the Los Humeros is shown and a table where the chemical composition of the separated water is indicated and the enthalpy of some of the wells of Los Humeros, Puebla, Mexico. [Spanish] Para inferir las distribuciones de presion y temperatura no perturbadas del fluido del yacimiento, se analizo una considerable cantidad de informacion proveniente de varias disciplinas, correspondiente a 42 pozos del campo geotermico de Los Humeros. Sobre la base de los datos analizados se desarrollaron modelos, en una y dos dimensiones, del yacimiento en un estado inicial. Los modelos revelan la existencia de cuando menos dos yacimientos. El primero y mas superficial se encuentra localizado entre 1600 y 1025 m.s.n.m. y es un yacimiento de liquido dominante. El perfil de presion de este yacimiento corresponde a una columna de agua en ebullicion aproximadamente entre 300 y 339 grados centigrados. El segundo yacimiento se

  10. Modernización del sistema de aire de alta presión de las corbetas misileras de la armada del Ecuador

    OpenAIRE

    Espinoza Estrella, Bryan; Orces, Eduardo

    2009-01-01

    El estudio se lo hace al sistema de aire de alta presión en las corbetas misileras de la Armada del Ecuador. Este sistema de aire trabaja con presiones elevadas de 206 bar, el cual sirve para suministrar aire comprimido al sistema de armamento y a los sistemas contraincendios: Por razón del excesivo tiempo que tardaba el sistema en presurizarse cuando se requería usarlo, se optó en el año 95 por suministrar aire directamente del compresor a las diferentes unidades de servicio, evitando ac...

  11. Diseño y predicción del funcionamiento de inyectores Venturi en riego localizado

    Directory of Open Access Journals (Sweden)

    Juan Manzano

    2014-12-01

    Full Text Available En la Universitat Politècnica de València, Valencia, España, se ha estudiado el diseño y funcionamiento de cuatro prototipos del inyector Venturi con técnicas de Dinámica de Fluidos Computacional (CFD, comparándo las con ensayos en laboratorio. Para cada prototipo, las geometrías definidas y analizadas han permitido simular el funcionamiento sin (G1 y con inyección (G2 para quimigación. En el caso G1, se presentan los gráficos del perfil de presiones en el eje del inyector para diversas velocidades, así como la distribución del campo de presiones y de la evolución de las diferencias de presión y pérdidas de carga frente al caudal principal. Para comparar los resultados obtenidos con CFD frente al resultado experimental, se calculó el error relativo. En el caso G2, se obtuvo la representación gráfica del el caudal de inyección frente al caudal principal. Las técnicas CFD exigen un buen ajuste del modelo para dar un resultado aceptable. Son interesantes para comparar geometrías, analizar sus variantes, realizar prediseños y aproximar ordenes de magnitud, pero es recomendable su ensayo en laboratorio para validar los resultados.

  12. LA FORMACIÓN PRÁCTICA DEL INGENIERO ELÉCTRICO EN LA UNIVERSIDAD LAICA ELOY ALFARO DE MANABÍ. EXPERIENCIAS CON EL USO DE UN SIMULADOR DE ENERGÍA EÓLICA

    Directory of Open Access Journals (Sweden)

    Miguel Escalona Reyes

    2016-01-01

    Full Text Available El presente trabajo se enmarca en el camino hacia la mejora en la formación experimental en la carrera de Ingeniería Eléctrica de la Universidad Laica Eloy Alfaro de Manabí (ULEAM, y se ha desarrollado con la intención de formar parte del material didáctico en el cual los estudiantes apoyen su aprendizaje práctico, considerando el desarrollo del mismo, no sólo el proceso de estudio que conlleva adquirir nuevos conocimientos, sino que además proporciona información respecto al uso de equipos para el aprovechamiento de energías renovables como lo es la energía eólica. En él se describe el proceso de conformación del equipo simulador para la generación de electricidad por medio de la energía eólica, y los requerimientos para su implementación efectiva; además, se presenta un manual para el desarrollo de las prácticas de laboratorio, utilizando el equipo elaborado, que contiene las actividades elegidas como una forma de acercar al alumno a las aplicaciones que pueden ofrecer la energía eólica como fuente de generación eléctrica. Lo anterior contribuye al mejoramiento del proceso de enseñanza-aprendizaje de los estudiantes en el eje de Práctica y Laboratorio, específicamente, en el área de la tecnología de generación energética con la utilización de energía eólica.PALABRAS CLAVE: Energías Renovables; Energía Eólica; Formación Práctica; Ingeniería Eléctrica; Proceso de Enseñanza Aprendizaje.THE PRACTICAL TRAINING OF THE ELECTRICAL ENGINEER IN THE LAY UNIVERSITY ELOY ALFARO FROM MANABÍ. EXPERIENCES IN THE USE OF A WIND´S ENERGY SIMULATORABSTRACTThis research work is based on improving the experimental training in Electrical Engineering course of study, in the “Eloy Alfaro” Lay University of Manabí (ULEAM and it has been developed with the aim to take part of teaching didactic material of the students as a support for their practical learning, taking into account for its development, not only the

  13. Desarrollo de un entorno de programación para un robot simulado Turtlebot-2 con brazo manipulador WIDOWX mediante la conexión V-REP y MATLAB

    OpenAIRE

    Fernández-Vega, Iván

    2016-01-01

    El objetivo principal de este Trabajo de Fin de Grado ha sido el de implementar un entorno de programación para un robot móvil Turtlebot-2 dotado de un brazo articulado WidowX. Para ello, se ha modelado este conjunto robótico en el simulador V-REP a partir de las descripciones físicas de los mismos, y se han ajustado diversos parámetros para que el comportamiento del robot simulado sea lo más parecido al del robot real. Para implementar las aplicaciones que controlen nuestro co...

  14. Análisis de eficiencia de algoritmos

    Directory of Open Access Journals (Sweden)

    Lovos, Edith

    2012-01-01

    Full Text Available La resolución de un problema usando una computadora puede ser modelada por diferentes algoritmos. De aquí la importancia de contar con herramientas que nos permitan seleccionar el algoritmo que sea más eficiente, es decir, el que insuma menos recursos del ordenador: tiempo y memoria necesarios para su ejecución. Existen dos formas de medir la complejidad de un algoritmo: análisis teórico y análisis empírico. En este trabajo se presenta la descripción del simulador, “SIMULA-ALGO”, junto con la propuesta de uso y detalles del diseño de la interfaz. Se presenta además una fundamentación teórica sobre las ventajas del uso de la simulación como recurso pedagógico-didáctico. El simulador se propone como recurso para la enseñanza aprendizaje del análisis teórico de eficiencia de algoritmos. El mismo está destinado a alumnos de los primeros años de carreras universitarias de licenciatura en sistemas. Los contenidos considerados en el simulador, requieren, para su comprensión, del uso de procesos cognitivos analíticos. El simulador pretende optimizar estos procesos en el alumno que lo usa. Así, por ejemplo, el simulador podrá realizar procesos rutinarios en forma rápida y efectiva, permitiendo que el alumno se concentre en los procesos analíticos que requiere la tarea.

  15. Design and Task Analysis for a Game-Based Shiphandling Simulator Using an Open Source Game Engine (DELTA3D)

    Science.gov (United States)

    2011-09-01

    Rodrigues, F. L. D. (2010).Sistema de realidade virtual para simulador visual de passadiço ( Virtual reality system for visual bridge simulator...products/shipsimulatorextremes Souza, I. (2007). Simulador de Realidade Virtual para o Treinamento de Biópsia por Agulha de Nódulos da Glândula de...Games, Shiphandling Simulator, Training, Virtual Environments, Simulation, Open Source, Brazilian Navy 16. PRICE CODE 17. SECURITY CLASSIFICATION OF

  16. Effects of Temperature and Pressure on Hot-Atom Reactions in Bromoethane; Effets de la Temperature et de la Pression sur les Reactions des Atomes Chauds dans le Bromoethane; Vliyanie temperatury i davleniya na reaktsii goryachikh atomov v bromehtane; Efectos de la Temperatura y de la Presion en las Reacciones de Atomos Calientes en el Bromoetano

    Energy Technology Data Exchange (ETDEWEB)

    Cole, A. J.; Mia, M. D.; Miller, G. E.; Shaw, P. F.D. [Nuclear Physics Laboratory, Oxford University, Oxford (United Kingdom)

    1965-04-15

    -Sign C y a la presion atmosferica, asi como a 18 Degree-Sign C y presiones de hasta 10{sup 4} atm. Ademas de los compuestos ya conocidos en este sistema, se han hallado pequeflas cantidades de bromoetano, 1,2-dibromoetano, mono y dibromo- propanos y mono, di, tri y tetra bromobutanos; tambien hay pruebas indirectas de produccion debromobutenos. Las reacciones dependientes de la difusion son complejas, y se pueden explicar suponiendo que en las proximidades del atomo caliente se produce una pirolisis del liquido por la que se forman radicales bromo- etilo y etileno. La adicion de radicales a este ultimo determina la formacion de bromuros que contienen mas de dos atomos de carbono, asi como sus rendimientos dependientes de la difusion. La disminucion de la temperatura o el aumento de la presion se traduce por lo general en un incremento del rendimiento atribuible a una menor velocidad de difusion. El. efecto es mas acusado en el rendimiento de 1, 2-dibromoetano producido principalmente por la reaccion difusiva de radicales bromoetilo, que se cuadruplica al aplicar una presion de 10{sup 4} atm debido a la supresion de la disociacion CH{sub 2}-CH{sub 2}Br Rightwards-Arrow-Over-Leftwards-Arrow CH{sub 2} = CH{sub 2} + Br bajo la influencia de la ''punta termica''. En cambio, la disociacion del radical (CH{sub 3} -CHBr) en bromoetano y un atomo de hidrogeno no es energeticamente viable, y el rendimiento de 1,1-dibromoetano es casi independiente de la presion. La variacion del rendimiento de bromoetano para grandes concentraciones de bromo en funcion de la temperatura y de la presion se aproxima al valor que se habia previsto. (author) [Russian] Izuchalis' vyhody soedinenij, soderzhashhih Br{sup 80m} kotoryj byl poluchen oblucheniem smesej bromjetan-bromina nejtronami 14 Mjev pri temperaturah 18 Degree-Sign C, -80 Degree-Sign C i -115 Degree-Sign C pri atmosfernom davlenii, a takzhe pri 18 Degree-Sign C i davlenijah do 10{sup 4} atmosfer. Pomimo soedinenij jetoj sistemy

  17. Optimización operacional de redes de distribución de agua potable con el fin de maximizar la uniformidad de presiones en los nodos de consumo

    Directory of Open Access Journals (Sweden)

    Diego Alejandro Araque Fuentes

    2005-11-01

    Full Text Available En el presente trabajo se muestra que con el desarrollo de un algoritmo determinístico se logra uniformizar el estado de presiones de servicio en una red de distribución de agua potable. Para lograr esto de forma óptima, se debe maximizar un Índice que relaciona la potencia por unidad de peso disipada por la red y disponible para disipar por la misma (Índice de Resiliencia [2], lo cual mejora la habilidad del sistema de distribución para enfrentar eventuales fallas en el mismo, retarda los procesos de renovación de tuberías y minimiza el nivel de fugas en la red. / The present paper will show that throughout the development of a deterministic algorithm the uniformity of the pressure service level in the Water Distribution Network (WDN can be maximized. To obtain this in an optimal way, one must maximize an Index that relates the power by unit of weight dissipated by the network and the power by unit of weight available to dissipate by the same one (Resilience Index [2], it improves the ability of the WDN to cope with possible failures in the system, slows down the pipes renovation processes and diminishes the level of leaks in the network.

  18. Geochemical evidences of the boiling phenomena in Los Humeros geothermal field; Evidencias geoquimicas del fenomeno de ebullicion en el campo de Los Humeros

    Energy Technology Data Exchange (ETDEWEB)

    Munguia Bracamontes, Fernando; Lopez Mendiola, Juan Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    The geochemical behavior of the fluids in the geothermal field Los Humeros suggests the existence of a reservoir of relatively low permeability, with hydrostatic pressure gradients and thermodynamic conditions of pressure-temperature close to the boiling point in stationary conditions, that is, non-disturbed. Nevertheless, the fluid geochemistry also indicates the presence of steam under stationary conditions, mainly in the fault, fracture, fissure, etc. zones. The steam diminishes progressively as the extraction time increases, being replaced by boiling fluid. [Espanol] El comportamiento geoquimico de los fluidos en el campo geotermico de Los Humeros sugiere la existencia de un yacimiento de relativa baja permeabilidad, con gradientes de presion hidrostatica y condiciones termodinamicas de presion-temperatura cercanas al punto de ebullicion a condiciones estables; es decir, no perturbadas. Sin embargo, la geoquimica de los fluidos tambien indica la existencia de vapor bajo condiciones estables, principalmente en las zonas de fallas, fracturas, fisuras, etc. El vapor disminuye progresivamente conforme aumenta el tiempo de extraccion, siendo reemplazado por fluido en ebullicion.

  19. Geochemical evidences of the boiling phenomena in Los Humeros geothermal field; Evidencias geoquimicas del fenomeno de ebullicion en el campo de Los Humeros

    Energy Technology Data Exchange (ETDEWEB)

    Munguia Bracamontes, Fernando; Lopez Mendiola, Juan Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    The geochemical behavior of the fluids in the geothermal field Los Humeros suggests the existence of a reservoir of relatively low permeability, with hydrostatic pressure gradients and thermodynamic conditions of pressure-temperature close to the boiling point in stationary conditions, that is, non-disturbed. Nevertheless, the fluid geochemistry also indicates the presence of steam under stationary conditions, mainly in the fault, fracture, fissure, etc. zones. The steam diminishes progressively as the extraction time increases, being replaced by boiling fluid. [Espanol] El comportamiento geoquimico de los fluidos en el campo geotermico de Los Humeros sugiere la existencia de un yacimiento de relativa baja permeabilidad, con gradientes de presion hidrostatica y condiciones termodinamicas de presion-temperatura cercanas al punto de ebullicion a condiciones estables; es decir, no perturbadas. Sin embargo, la geoquimica de los fluidos tambien indica la existencia de vapor bajo condiciones estables, principalmente en las zonas de fallas, fracturas, fisuras, etc. El vapor disminuye progresivamente conforme aumenta el tiempo de extraccion, siendo reemplazado por fluido en ebullicion.

  20. Contribuciones de la neurociencia cognitiva al diseño de políticas científicas y sociales para niños en situación de pobreza

    Directory of Open Access Journals (Sweden)

    Sebastián Javier Lipina

    2011-01-01

    Full Text Available Los procesos de globalización y sus demandas de competitividad incrementan en forma continua las presiones educativas y laborales, así como las demandas familiares en el cuidado de niños y ancianos. En países con mayor incidencia de pobreza, ello incrementa la probabilidad de que diferentes factores de riesgo a nivel de la salud física y del desarrollo social, cognitivo y afectivo, impacten sobre el capital mental de sus poblaciones. Un aspecto crítico para las políticas sociales y científicas es que dado que la pobreza tiende a replicarse de forma intergeneracional, parte de lo que se transmite de padres a hijos son carencias en la estimulación cognitiva y emocional. Durante la última década, la neurociencia cognitiva generó un cuerpo de información que propone contribuir al desarrollo de estrategias de intervención, orientadas a mejorar las oportunidades de desarrollo del capital mental de aquellas poblaciones en condiciones de riesgo social.

  1. Diseño de un Sistema para la Mejora de la metrología de productos industriales basada en visión artificial

    OpenAIRE

    CAZORLA GARCIA, CRISTIAN

    2015-01-01

    [ES] El objeto del presente TFG es proponer una nueva solución basada en visión artificial para abordar el problema de la medición de objetos en entornos industriales. El alumno tendrá que implementar en un simulador del entorno así como algoritmos de visión con objeto de proporcionar una solución al problema. Por último, tendrá que realizar un estudio de las mejoras que se obtienen con respecto a las utilizadas en industria en la actualidad. Cazorla Garcia, C. (2015). Diseño de un Sistema...

  2. Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

    2007-07-15

    -tiempo o de Gibson. Este metodo esta basado en el fenomeno del golpe de ariete y es aplicado al caso de una tuberia de presion de tuberia hidraulica. La version del metodo usado en el presente trabajo consiste en la medicion, durante el rechazo total de carga, del historial de tiempo y del cambio de presion en una seccion de la tuberia de presion y relaciona este cambio de presion con el nivel del embalse de la central hidroelectrica. El flujo volumetrico se determina mediante la integracion del incremento de la diferencia de presion medida con respecto al tiempo. La medicion del flujo fue posible gracias a la poca influencia de la entrada del flujo a la tuberia de presion, de 300 m longitud, evitando asi introducir un error considerable en la medicion. Se aplicaron y adoptaron para la medicion los criterios de la norma IEC-41-1991 y experiencias previas. Se utilizo un sistema de adquisicion de datos rapido y eficiente, el cual incluye una tarjeta de 16 bit. El flujo fue calculado usando un programa de computo desarrollado y probado en varios casos anteriores. Los resultados obtenidos con el metodo Gibson fueron utilizados para la calibracion de un sistema de medicion en linea basado en el metodo relativo de Winter-Kennedy. Este ultimo se usa comunmente para el monitoreo continuo del flujo de turbinas hidraulicas, siempre y cuando la calibracion en sitio haya sido realizada usando los resultados de las mediciones de un metodo absoluto. Una vez medido el flujo y la potencia de salida, se calculo la eficiencia para diferentes condiciones de operacion. Se discuten y presentan los resultados obtenidos en una curva, la cual muestra las mejores condiciones de operacion basadas en la mayor eficiencia. Los detalles de la instrumentacion, su instalacion y otros resultados obtenidos se discuten tambien en el presente articulo.

  3. DESCRIPCIÓN DE UN SISTEMA PARA LA MEDICIÓN DE LAS PRESIONES PLANTARES POR MEDIO DEL PROCESAMIENTO DE IMÁGENES: FASE I

    Directory of Open Access Journals (Sweden)

    Christian Andrés Díaz

    Full Text Available La medida de la presión plantar es fundamental para conocer la distribución de las fuerzas en la planta del pie. Estos valores son importantes para el diagnóstico y tratamiento de diferentes patologías como úlceras diabéticas en la planta del pie y presencia de deformidades en extremidades inferiores, entre otras. En el presente artículo se describe el desarrollo de un podobarógrafo para el análisis de la huella plantar, cuyo desarrollo incluyó la fabricación de un podoscopio, la selección de un material transductor adecuado y el desarrollo del software para el procesamiento de las imágenes capturadas por una cámara de video. El dispositivo propuesto PodoMED permite realizar un análisis dinámico y estático de la huella, pues aparte de mostrar cómo es la distribución de presiones en la planta del pie durante la marcha, por medio de imágenes en seudocolor, tiene la opción de emitir una valoración de la huella, donde se muestran medidas como el índice de valgo, el ángulo de Clarke, el índice de Hernández Corvo, entre otros. Para el desarrollo de este proyecto se realizaron ensayos experimentales para minimizar el ruido de la imagen, lo cual se logró con la utilización de un filtro físico y otro para la imagen por medio de software. Para una etapa futura, se planea la calibración y validación del sistema, con lo cual se pretende brindar mayor confiabilidad y repetibilidad.

  4. Factores determinantes del nivel de compromiso medioambiental voluntario adquirido por los hoteles cotizados europeos

    OpenAIRE

    Patricia Milanés Montero; Esteban Pérez Calderón; Francisco Javier Ortega Rossell

    2012-01-01

    Ante las importantes presiones que la actividad hotelera ejerce sobre el medioambiente, la ausencia de regulación de las actuaciones responsables y la escasez de investigaciones al respecto aparece la imperiosa necesidad de aportar luz en este sentido. Por ello, en este trabajo se analiza el compromiso medioambiental corporativo de los hoteles cotizados europeos; se utiliza como metodología el análisis de contenidos y se detectan los factores determinantes de las actuaciones responsables con ...

  5. ¿Cuáles son las Razones Subyacentes al Éxito Educativo de Corea del Sur?

    OpenAIRE

    García Ruiz, María José; Arechavaleta Pintó, Carmen

    2011-01-01

    El éxito educativo de los alumnos de Corea del Sur debe gran parte de su mérito a toda una serie de estructuras, presiones, valores y objetivos que están presentes en la cultura escolar y en la sociedad coreana, más que sólo a virtudes intrínsecas de las escuelas de este país. Las altas puntuaciones de los alumnos coreanos en las diversas evaluaciones internacionales de la educación pueden ser atribuidas, de modo especial, a dos aspectos que constituyen un legado de la ética confuciana en est...

  6. Fission gas pressure build-up and fast-breeder economy; Accumulation de la pression des gaz de fission et economie des reacteurs surgenerateurs a neutrons rapides; Nakoplenie davleniya gazov produktov deleniya i ehkonomika reaktorov-razmnozhitelej na bystrykh nejtronakh; Aumento de la presion de los gases de fision y economia de los reactores reproductores rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, P [Kernforschungszentrum, Karlsruhe (Germany)

    1962-03-15

    exercee sur la gaine, il a utilise trois modeles ou le gaz etait contenu dans des interstices relies entre eux, dans des interstices separes ou dans un orifice central. Le memoire traite de la variation de la pression en fonction du volume libre (densite du combustible) et de la temperature. Des gaines en materiaux tres resistants, comme l'Inconel-X et le molybdene, ont pu supporter la pression des gaz de fission aux temperatures de fonctionnement . Malheureusement, les sections efficaces d'absorption de ces materiaux sont plus elevees que celle de l'aluminium. Les resultats de calculs multigroupes sont presentes, pour montrer comment ces materiaux de gainage et la diminution de la densite du combustible influent sur la masse critique et le rapport de surgeneration dans les reacteurs surgenerateurs de petites ou moyennes dimensions. (author) [Spanish] El costo del ciclo de combustible y el periodo de duplicacion en los reactores reproductores de neutrones rapidos dependen en gran medida del grado de combustion que pueda alcanzarse. La utilizacion de combustible en forma de oxido o de carburo permite obtener un grado de combustion de 100 000 MWd/t. Cuando se emplean elementos combustibles con revestimiento, el aumento de presion de los gases de fision constituye un factor limitativo. En el caso del elevado grado de combustion previsto, una fraccion considerable de los gases de fision penetra en los peros del material, contribuyendo asi a aumentar la presion en el interior de la envoltura. Sobre la base de los rendimientos de fision y de las cadenas de desintegracion conocidas, el autor ha evaluado la produccion de gas y el aumento de presion. Para calcular la presion ejercida sobre la envoltura, ha empleado tres modelos fisicos en que el gas estaba contenido en poros conectados entre si, en poros separados, o en un orificio central. El autor analiza la variacion de la presion, en funcion del volumen libre (densidad del combustible) y de la temperatura. Las envolturas de

  7. INFLUENCIA DE LA PRESIÓN ATMOSFÉRICA EN LAS TRANSMISIONES A FRECUENCIA 2.4 GHz

    OpenAIRE

    González Romero, Pedro Vicente; Espina Ávila, Luis Gerardo

    2012-01-01

    La presente investigación se planteó como propósito fundamental determinar la influencia de la presión atmosférica sobre una señal transmitida en una frecuencia de 2.4 GHz. La investigación es de tipo explicativa, con diseño metodológico experimental. Mediante ella se obtiene la atenuación de una señal de 2.4GHz a diferentes presiones atmosféricas y se determinan las gráficas que muestran el comportamiento observado. Como resultado de esta investigación se observó que sí existe una influencia...

  8. Proposta e simulação de uma arquitetura RISC

    OpenAIRE

    Fredy Joao Valente

    1991-01-01

    RISC - Uma nova tendência em arquitetura de computadores. Este trabalho apresenta um estudo de como surgiu esta nova arquitetura, e suas características básicas, que a diferencia das arquiteturas convencionais. Uma proposta de microprocessador RISC é apresentada, com sua rota de dados completamente detalhada. Um simulador para arquitetura RISC foi então construído, para se testar este microprocessador. Para validar o simulador, que é a idéia principal deste trabalho, e para se avaliar a arqui...

  9. Planificación de la producción en una industria de consumo masivo utilizando la Teoría de las Restricciones

    OpenAIRE

    Cabrera Ojeda, Daniel Alejandro

    2014-01-01

    102 páginas : ilustraciones,29 x 21 cm + CD-ROM 5335 Se realizaron parametrizaciones en un simulador, para representar la realidad actual de una compañía manufacturera, y de cómo se debe manejar, la planificación de la producción y la cadena de distribución con base en la teoría de las restricciones. Lo que conllevó que se tenga una disminución de 15 800 000 USA dólares en los niveles de inventario a lo largo del período analizado; es decir, al correr la simulación antes de la implementaci...

  10. Un modelo de eventos discretos para la simulación de sistemas de tiempo real

    OpenAIRE

    Páez, Francisco E.; Urriza, José M.; Orozco, Javier D.; Buckle, Carlos

    2011-01-01

    En este trabajo se presenta un modelo de eventos discretos para el diseño de simuladores de Sistemas de Tiempo Real. Los simuladores sirven para realizar comprobaciones de algoritmos, modelos, técnicas y para evaluar métricas de rendimiento. El modelo de eventos discretos se ajusta perfectamente a los sistemas dinámicos discretos como lo son los Sistemas de Tiempo Real. El modelo se desarrolla empleando la técnica de grafo de eventos, debido a su sencillez y facilidad de implementación.

  11. Aproximación matemática al proceso de galvanorrecocido en productos siderúrgicos planos

    Directory of Open Access Journals (Sweden)

    Pérez, A.

    1998-05-01

    Full Text Available A short review of the kinetics models for the formation of Fe-Zn alloy phases in the galvannealing process is presented. It will focus on the continuous process which is often used by the automotive industry. A first mathematical approach of the kinetics growth of the δ phase has been done, using a continuous hot-diping process simulator which resembles the conditions of the galvannealing process in production lines. Hold time and the galvannealing temperature as well as the weight of the coating were varied. The preliminary results of the iron content and proportion of δ phase in the coating are in agreement with the results obtained by other authors.

    Se revisan brevemente los modelos cinéticos descritos para la formación de las fases de aleación Zn-Fe durante el proceso de galvanorrecocido de chapa, con especial énfasis en el proceso continuo, con destino a la industria del automóvil. Se ha realizado una primera aproximación matemática al crecimiento cinético de la fase delta utilizando un simulador de recubrimiento en continuo por inmersión en caliente produciéndose el galvanorrecocido por calentamiento de la chapa galvanizada exactamente después de su salida del baño de zinc con objeto de aproximarse a las condiciones reales imperantes en las líneas de producción. Los parámetro variables han sido: el tiempo y la temperatura de galvanorrecocido y el peso de recubrimiento. Los resultados iniciales del contenido de hierro del recubrimiento y de contenido de fase delta están de acuerdo con los resultados obtenidos por otros autores.

  12. The Use of Prestressed Concrete Vessels in the French Power Reactor Programme; Les caissons en beton precontraint dans le programme francais des reacteurs de puissance; Korpusy iz predvaritel'no napryazhennogo betona vo frantsuzskoj programme ehnergeticheskikh reaktorov; Empleo de recipientes de presion de hormigon pretensado en el programa frances de reactores de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Conte, F. [Centre d' Etudes Nucleaires de Marcoule (France); Dambrine, C. [Centre d' Etudes Nucleaires de Fontenay-aux-Roses (France); Gaussot, D. [Electricite de France, Clamart (France)

    1963-10-15

    de la pression de service et de toutes manieres, une augmentation notable des dimensions, ce qui permet d'envisager des solutions du type integre. (author) [Spanish] G3 de Marcoule y en el reactor EDF3, en construccion en Chinon. Los reactores se encuentran en servicio desde 1959 y 1960, respectivamente; el Comissariat a l'energie atomique indica los problemas que ha planteado la construccion de los recipientes de presion y las observaciones efectuadas durante el funcionamiento de los reactores, que ponen de manifiesto la gran seguridad de los mencionados recipientes. La construccion del recipiente de presion del reactor EDF3, que comenzo en Chinon en el segundo semestre de 1961, prosigue actualmente y quedara terminada a fines de 1963. L'Electricite de France expone los motivos de la eleccion de este tipo de recipiente, los resultados de los calculos y de los ensayos efectuados con maquetas, asi como los problemas planteados por sir construccion. Se han llevado a cabo varios estudios sobre las perspectivas del empleo del hormigon pretensado en los reactores. Al parecer, este material permite obtener un aumento de la presion de trabajo y de todas maneras, un incremento notable de las dimensiones, lo que a su vez permite tomar en consideracion soluciones de tipo integrado. (author) [Russian] Izlagaetsya vopros o primenenii predvaritel'no napryazhennogo betona dlya reaktorov G.2 i G.3 v Markule i dlya stroyashchegosya v Shinone reaktora EDF.3. Reaktory dostigli mosnosti sootvetstvenno v 1959 i 1960 godakh; KAEH otmechaet problemy, kotorye voznikli v protsesse stroitel'stva korpusa reaktora, i izlagaet filosofiyu nablyudenij, kotorye prodemonstrirovali vysokuyu bezopasnost' ehtikh ustanovok. K stroitel'stvu korpusa reaktora EDF.3 v SHinone pristupili vo vtoroj polovine 1961 goda; stroitel'stvo budet zaversheno k kontsu 1963 goda. ''Ehlektrisite de Frans'' ob{sup y}asnyaet prichiny vybora takogo korpusa, privodit rezul'taty raschetov i provedennykh na makete ispytanij, a

  13. Plataforma virtual para el análisis del rendimiento y la seguridad en redes de sensores inalámbricos

    OpenAIRE

    Díaz Suárez, Álvaro

    2014-01-01

    En este trabajo se propone una plataforma virtual (Simulador de redes de sensores inalámbricas mediante software ejecutado en un PC) la cual integra simulación funcional de redes de sensores inalámbricas, integración de RTOS (Real-Time Operating System) y estimación de prestaciones (tiempo de ejecución y consumo), junto con la capacidad de simular de ataques. Además, el simulador ejecuta exactamente el mismo código que se ejecutará en el nodo físico y se generará exactamente el mismo tráfico ...

  14. Simulación de Tareas Aperiódicas y Esporádicas de Tiempo Real mediante un Modelo de Eventos Discretos

    OpenAIRE

    Paez, Francisco Ezequiel; Urriza, José M.; Orozco, Javier Dario

    2015-01-01

    Este trabajo presenta una extensión a un modelo de eventos discretos para el diseño de simuladores de Sistemas de Tiempo Real con tareas periódicas, incorporando tareas de tipo esporádico y aperiódico. Además, se estudia el soporte para jitter y offset. El modelo es diseñado empleando la técnica de grafo de eventos, y se ajusta a los sistemas dinámicos discretos como lo son los Sistemas de Tiempo Real. En la actualidad, el uso de simuladores para realizar comprobaciones de algoritmos, modelos...

  15. Project of energy saving in compressed air; Proyecto de ahorro de energia en aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Automatizacion, Productividad y Calidad S.A. de C.V. Puebla, (Mexico)

    2005-07-01

    The objective of this project is to reduce the operation costs by means of the energy saving through the use of the compressed air system. For this purpose the solenoid valves controlled per time and the manually acted valves of sphere must be replaced by pneumatic purges that remove from the system the condensed humidity without discharging air and which act automatically when the water reaches the level of unloading in its deposit. The pressure level is the reduction of the operation rank of pressure in the compressors, satisfying the operation requirements of the process equipment. [Spanish] El objetivo de este proyecto es reducir el costo de operacion mediante el ahorro de energia en la utilizacion del sistema de aire comprimido. Para ello se tienen que remplazar las valvulas solenoides controladas por tiempo y valvulas de esfera actuadas manualmente por purgas neumaticas que remueven del sistema la humedad condensada sin descargar aire y que actuan en forma automatica al alcanzar el agua el nivel de descarga en su deposito. El nivel de presion es la reduccion del rango de operacion de presion de los compresores, satisfaciendo los requerimientos de operacion de los equipos de proceso.

  16. El radiorenograma en la hipertensión arterial nefrógena

    OpenAIRE

    Cárcamo Brado de La Rueda, Víctor

    2014-01-01

    Han sido estudiados 43 pacientes hipertensos, todos ellos con presiones arteriales sobre 150 la sistólica y 90 la diastólica. 14 de estos pacientes ignoraban tener hipertensión arterial, la cual fue encontrada al hacer el examen físico del paciente. Se han practicado pruebas de función renal (Depuración de creatinina, excreción de fenolsulfotaleína, depuración uréica, dosaje de úrea y creatinina sanguínea, prueba de Addis), urografía excretoria, aortografías, electrocardiograma, examen de fo...

  17. Manejo costero integrado y desarrollo sostenible en zonas costeras. El caso del programa de manejo de recursos costeros del Ecuador en el Golfo de Guayaquil

    OpenAIRE

    Soria Freire, Vladimir

    2005-01-01

    La investigación se asienta en el debate académico del desarrollo sostenible, con énfasis en el análisis de la importancia de los ecosistemas costeros en la reproducción de ciclos ecológicos y de servicios ambientales, así como, en las presiones que sufren debido al desarrollo de actividades que surgen de la propia explotación de los recursos naturales, como la pesca, acuicultura y turismo; y de otro tipo de actividades que tienen su afectación en los manglares, aguas de los estuarios, golfos...

  18. Compactadoras de placas

    Directory of Open Access Journals (Sweden)

    Chinchilla, M.

    1962-12-01

    Full Text Available Los rendimientos logrados mediante el empleo de la vibración en la compactación de suelos, han inducido a los fabricantes de maquinaria auxiliar (ver la compactación de suelos en el número 138 al estudio, experimentación y fabricación de nuevos tipos de máquinas compactadoras por vibración, de rendimientos óptimos, con las que se consigan ángulos de influencia menores de las presiones transmitidas y en las que la relación compactación/potencia empleada sea mayor.

  19. Mejoras del Método Pilates en el equilibrio

    OpenAIRE

    Sobrín-Valbuena, C.V.; Montil Jiménez, Marta Matilde; García López, Óscar

    2013-01-01

    Pilates es un método de acondicionamiento físico cuyos beneficios se han extendido al mundo sanitario. Diferentes estudios muestran que, entre otros beneficios, Pilates ayuda a mejorar la postura. Una evaluación objetiva de la misma puede ser obtenida por el análisis del equilibrio. El propósito del estudio fue evaluar, mediante plataforma de presiones, el equilibrio en dos grupos, los que realizan Pilates y los que no lo realizan. Se evaluaron a 124 personas divididos en dos grupos: 59 perso...

  20. La actividad cafetalera en Los Santos: diagnóstico para un análisis de los medios de vida en la agrocadena. (SDT 002_2009)

    OpenAIRE

    Valenciano Salazar, Jorge Andrey

    2008-01-01

    El presente documento pretende presentar una visión general sobre la Región de Los Santos (específicamente los cantones de Tarrazú, Dota y León Cortes) desde el punto de vista económico, institucional y ambiental; todos estos aspectos en relación al cultivo del café, el cual es el cultivo predominante en la región. El objetivo de este cuaderno de trabajo es presentar un diagnostico general sobre las presiones sufridas por las familias cafetaleras de la región, específicamente: plagas, ...

  1. Contribución al conocimiento de la reproducción de Podocnemis Lewyana Dumeril (Reptilia: Quelonia: Pelomedusidae

    Directory of Open Access Journals (Sweden)

    Castaño Mora Olga Victoria

    1986-12-01

    Full Text Available En Colombia se encuentran 5 especies del Género Podocnemis : P. expansa, P. lewyana, P. sextuberculata , P. unifilis y P. vogli. De estas P. lewyana es la única que se encuentra en la zona Norte de nuestro país y es endémica para la región que abarca las hoyas del Magdalena y del Sinú.La presion human a la que esta sometida Podocnemis lewyana es muy fuerte, esto sumado a su endemismo, hace que su esperanza de supervivencia se reduzca aceleradamente ; los pescadores de la zona son unánimes en manifestar que su número disminuye notablemente, año tras año

  2. Analysis of response patterns on the MMPI-2 in psychiatric prison inmates

    Directory of Open Access Journals (Sweden)

    Eduardo Osuna

    2015-01-01

    Full Text Available Se ha realizado un estudio ex post facto en una población de 102 penados psiquiátricos que respondieron bajo instrucciones estándar a la adaptación española del MMPI-2, con el objetivo de conocer el estado mental informado en el MMPI-2, así como el comportamiento de los indicadores de simulación y de disimulación. En los protocolos de respuesta no se observaron casos de outliers, patrones de respuestas totalmente azarosos o extremadamente aquiescentes, al tiempo que eran consistentes. Todos los penados psiquiátricos fueron clasificados, en consonancia con el diagnóstico psiquiátrico, en las escalas clínicas básicas como casos clínicos en la díada psicótica (i.e., esquizofrenia e ideación paranoide. Las escalas e índices de simulación utilizados (i.e., F, K, Fb, F-K, Fp, Ds y FBS los clasificaron como simuladores, en tanto las escalas de medida de la disimulación L, Wsd y Od los clasificaron como disimuladores. Estas escalas, que forman parte del manejo de la impresión, esto es, de la manipulación favorable y consciente de la imagen, no informan de casos en poblaciones de simuladores. Así, estas escalas serían indicadores robustos de no simulación. Finalmente, se discuten las implicaciones de estos resultados para la práctica forense.

  3. El Desastre del 96: Una forma educativa de explicar las reacciones fisiológicas producidas como consecuencia de la exposición a la baja presión de oxígeno a gran altitud usando la película Everest (2015

    Directory of Open Access Journals (Sweden)

    Germán DOMÍNGUEZ VÍAS

    2018-01-01

    Full Text Available El Desastre del 96 del Monte Everest se refiere a los eventos ocurrido del 10 al 11 de mayo de 1996, cuando ocho personas atrapadas en un temporal perdieron la vida, algunos durante el ascenso y, aquellos que ya habían hecho cumbre, mientras descendían. La película Everest (2015 refleja fielmente los síntomas previos ocurridos durante la ascensión, razón importante para comprender los efectos de la altura y de las bajas presiones de gases sobre el cuerpo humano. En este trabajo se aborda ambos problemas, Everest puede ayudar al alumnado a entender y reflexionar sobre los desafíos para la homeostasis corporal que tienen lugar a grandes alturas.

  4. Noise reduction in steam-vent points at the Cerro Prieto geothermal field, BC; Reduccion del ruido en puntos de desfogue en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2008-01-15

    Steam silencers have been placed on the power units regulation system of the Cerro Prieto geothermal field, but not where the steam-pipes vent high-pressure steam (rupture disks). Moreover, the power-unit silencers are large and their abilities to reduce noise depend on an external, uncontrollable factor: pores sizes in the volcanic rocks they are made of. Thus a compact, economic and relatively easy to construct metallic silencer was designed to be used at several points of dry-steam venting to minimize the noise. The design was based on orifice-plate equations and a prototype was constructed and tested. It proved capable of reducing noise by 30 decibels for atmospheric discharges of primary steam at operating pressures. The size of the silencer can be adjusted to the particular needs of each vent case. [Spanish] En el campo geotermico de Cerro Prieto solo existen silenciadores de vapor en el sistema de regulacion de las plantas generadoras, pero no en los sitios de desfogue de vapor a alta presion en los vaporductos (discos de ruptura). Ademas, los silenciadores de las plantas son muy robustos y su capacidad de reduccion del ruido depende de un factor externo no controlable, como es el tamano del poro de la roca volcanica con el que estan construidos. Por lo tanto, se diseno un silenciador metalico compacto, economico y relativamente facil de fabricar, para utilizarse en diversos puntos de descarga de vapor seco a fin de minimizar el ruido. El diseno se realizo con base en las ecuaciones de la placa de orificio. Se construyo un prototipo cuyas pruebas demostraron que es capaz de reducir el ruido hasta en 30 decibeles, al descargar desde la presion de operacion de vapor primario hacia la presion atmosferica. Las dimensiones del silenciador pueden ajustarse a las necesidades particulares de cada caso de desfogue.

  5. Protocolo para evaluar y comparar la respuesta al contacto por indentación esférica de un sistema integrado por un recubrimiento cerámico depositado sobre un acero de herramienta

    OpenAIRE

    Cordier, Delphine

    2009-01-01

    En aplicaciones como el conformado en frío donde las herramientas están sometidas a diversas cargas, se usan materiales para herramientas como aceros rápidos y metales duros recubiertos. En estas aplicaciones, los impactos sucesivos inducen presiones que pueden ocasionar el fallo por fatiga. Por ello, es necesario establecer las condiciones límite de trabajo de los materiales para optimizar la vida útil de las herramientas. En este trabajo, el sistema sustrato/recubrimiento ana...

  6. High intensity Discharge lighting; Alumbrado de alta intensidad de descarga

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza E, Ernesto J [Manufacturera de Reactores, S. A., Mexico, D. F. (Mexico)

    1994-12-31

    This paper gets into contact with some fundamentals in the operation of high discharge intensity lamps. There are useful definitions, as well as the study of the operation of high pressure sodium lamps and of metallic additives operating at less than nominal power. [Espanol] Este trabajo pone al lector en contacto con algunos fundamentos de la operacion de las lamparas de alta intensidad de descarga (HID). Se encuentra con definiciones utiles, asi como el estudio de la operacion de las lamparas de sodio en alta presion y de aditivos metalicos operando a una potencia menor que la nominal.

  7. High intensity Discharge lighting; Alumbrado de alta intensidad de descarga

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza E, Ernesto J. [Manufacturera de Reactores, S. A., Mexico, D. F. (Mexico)

    1993-12-31

    This paper gets into contact with some fundamentals in the operation of high discharge intensity lamps. There are useful definitions, as well as the study of the operation of high pressure sodium lamps and of metallic additives operating at less than nominal power. [Espanol] Este trabajo pone al lector en contacto con algunos fundamentos de la operacion de las lamparas de alta intensidad de descarga (HID). Se encuentra con definiciones utiles, asi como el estudio de la operacion de las lamparas de sodio en alta presion y de aditivos metalicos operando a una potencia menor que la nominal.

  8. Gasto no obligatorio de los municipios. Una muestra de ayuntamientos valencianos

    OpenAIRE

    Margareto Layunta, Leonardo

    2015-01-01

    El Ayuntamiento es la institución de Gobierno que mayores presiones recibe, al ser la más accesible para los ciudadanos, como instancia de poder más próxima y los municipios, por su parte, intentan responder a esa presión financiando una serie de gastos que no recogen como obligatorios ni la Ley Reguladora de las Bases del Régimen Local (LBRL), aprobada en 2005 , ni el resto de leyes que abordan esta cuestión. La legislación vigente establece cuáles son las obligaciones que deben atende...

  9. La semilla de Campsiandra angustifolia (Fabaceae:Caesalpiniodeaecomo un reflejo de las presiones selectivas sobre su dispersión y establecimiento

    Directory of Open Access Journals (Sweden)

    Alejandro G Farji-Brener

    2005-06-01

    Full Text Available Evaluamos indirectamente las presiones selectivas sobre la dispersión y el establecimiento en Campsiandra angustifolia, un árbol de la Amazonía Peruana dispersado por agua, analizando variaciones de la relación entre el volumen ocupado por las estructuras de dispersión y de establecimiento en sus semillas. Medimos un total de 535 semillas de 13 árboles ubicados en tres hábitats diferentes, las cuales presentaron una gran variación en su volumen total. Independientemente del tamaño de la semilla y de la ubicación del árbol de origen, la relación entre el volumen asignado a estructuras de establecimiento y a estructuras de dispersión fue relativamente constante (~1 y presentó una distribución normal con baja asimetría, indicando selección estabilizante. Este resultado sugiere que los procesos de dispersión y establecimiento poseen una importancia relativa similar para C.angustifolia en los hábitats estudiados. En especies con semillas empaquetadas, el volumen relativo ocupado por estructuras relacionadas con la dispersión o el establecimiento podría ser una medida más adecuada de la solución de compromiso entre estos dos procesos que la variación del tamaño de la semillaThe seeds of Campsiandra angustifolia (Fabaceae:Caesalpiniodeae as a reflex of selective pressures on dispersal and establishment. We indirectly evaluated the selective pressures on dispersal and establishment of Campsiandra angustifolia, a common water-dispersed tree from the Peruvian Amazon, analyzing the variation in the relationship between the volume occupied by dispersal and establishment structures in a total of 535 seeds from 13 trees located at three different habitats. The seeds differed one order of magnitude in their total volume. However, independently of their size and the location of the maternal tree, the relationship between the volume occupied by dispersal and establishment structures was relatively constant (~1 and showed a normal

  10. Virtual test bench as a complement to study thermal area: application in vapor compression systems

    Directory of Open Access Journals (Sweden)

    Juan Manuel Belman-Flores

    2015-01-01

    Full Text Available Este artículo describe un simulador educativo desarrollado en el software Engineering Equation Solver para representar el comportamiento de un sistema de compresión de vapor. La aplicación está enfocada con propósitos educativos, particularmente para que estudiantes de ingeniería adquieran habilidades en el manejo de instalaciones de refrigeración. Mediante el uso de este simulador, los estudiantes tendrán la capacidad de analizar fácilmente la infl uencia que tienen parámetros medidos experimentalmente (como la velocidad de rotación del compresor, el fl ujo volumétrico y la temperatura de fl uidos secundarios sobre la efi ciencia energética del sistema y sus componentes principales. El banco virtual consta de una pantalla principal que muestra un esquema general del sistema de compresión de vapor con parámetros de entrada y de salida. Desde la pantalla principal, el desempeño de los componentes principales puede ser analizado. Finalmente, este banco de pruebas virtual ha sido probado por estudiantes de ingeniería, concluyendo que el simulador es una herramienta de apoyo que permite mejorar el aprendizaje de las diferentes áreas del conocimiento.

  11. EFECTO DE LA PRESIÓN SOBRE LAS FUGAS DE AGUA EN UN SISTEMA DE TUBERÍA SIMPLE EFFECT OF PRESSURE OVER LEAKS IN A SIMPLE PIPELINE SYSTEM

    Directory of Open Access Journals (Sweden)

    Luis Javier Montoya

    2012-06-01

    Full Text Available Este artículo es un resultado del proyecto de investigación ''Estudio del efecto de la presión en una red de distribución sobre las fugas de agua, utilizando una red de experimentación en laboratorio'' y en él se analizan las relaciones entre la sobrepresión generada por el transiente hidráulico originado por el cierre rápido de una válvula y las fugas inducidas mediante orificios en un sistema experimental de tuberías. El presente artículo se concentra en describir las alteraciones en la onda de presión cuando se presentan fugas de agua en un sistema de tuberías simple. Para ello, se analizan los resultados obtenidos en un montaje experimental y se comparan las ondas obtenidas con y sin fuga, en condiciones similares de caudal. Se observó que existe un decaimiento en las presiones máximas en el sistema al comparar las presiones en los sistemas con fuga y sin fuga. Comparando los resultados obtenidos para el ensayo con fugas y sin fugas se observa una mayor atenuación de la onda ante la presencia de fugas.

  12. Entomología: Biodiversidad, Teorías Poblacionales y Biología del Altruismo

    Directory of Open Access Journals (Sweden)

    Juan A. SCHNACK

    2005-01-01

    Full Text Available Se analizan algunos aportes de la entomología al desarrollo y estado del arte de tres temas relevantes de la ecología y de la biología evolutiva. Para tal fin se discuten cuestiones relativas a la diversidad biológica en contextos inter e intra-específico, al crecimiento y a la regulación de las poblaciones animales, considerándose enfoques particulares de las genéricamente denominadas "teorías poblacionales", y a las bases biológicas del comportamientode los insectos sociales. Esto último como base para la interpretación de la eventual manifestación de presiones de selección y extinciones diferenciales a nivelesbiológicos por encima del individual (selección familiar o de parentela, "kin selection".

  13. Al-Qurû’ fi Al-Qur’an ‘Inda Al-Anbary fi Al-Adhdâd

    Directory of Open Access Journals (Sweden)

    Raushani Azza

    2018-03-01

    Full Text Available This study examines about the term al-Qurû in the Qur’an. Al-Qurû is one of the most popular discussions among muslim scholars and mufasir, both in terms of language and fiqh. However, there is a bate among muslim scholar and mufasir about the meaning of al-Qurû. It’s because al-Qurû is one of the sentence of al-Adhdâd wich has two meaning, especially in the Qur’an, namely haid (menstruation and thahr. One of the most popular muslim scholar who concern in Qur’an and Arabic is al-Anbari with his book al-Adhdâd. Al-Anbari explains that Qurû has two meanings, First, al-Qurû in etymology is the form of Jama’ from aqra and qurû. Second, al-Qurû has a meaning of menstruation, thahr, or the period of iddah as a sign of being allowed to remarry after certain period of time.

  14. Los simuladores como medios de enseñanza en la docencia médica

    Directory of Open Access Journals (Sweden)

    Yanetsi Contreras Olive

    2018-04-01

    Full Text Available La simulación en la educación médica ha presentado un desarrollo importante a nivel mundial. Se ha convertido en un medio de enseñanza-aprendizaje mediante el cual se favorece el desarrollo de competencias, especialmente la adquisición de habilidades clínicas, previo al contacto real con el paciente y fomenta la seguridad para este, mediante la adquisición de destrezas para disminuir la posibilidad de errores o complicaciones en la ejecución de procedimientos. Las aplicaciones de la simulación son múltiples y cuentan con un potencial ilimitado, la mayoría de las experiencias involucran el entrenamiento de habilidades y la adquisición del conocimiento. Este trabajo expone algunos de los fundamentos de la simulación médica como medio de enseñanza y ofrece un panorama conceptual respecto a la simulación y se describen las características del público al que va destinado el medio.

  15. Al-Âyah al-Mutasyâbihât al-Lafzhiyyah fi Sûrah al-An’âm ‘Inda al-Kirmâny

    Directory of Open Access Journals (Sweden)

    Hikmatiar Pasya

    2017-07-01

    Full Text Available This paper discusses about the verses of mutasyâbihât in the Quran. The debate of this verses caused various opinions. The meaning of the mutasyâbihât in this paper is the similarity and difference of the words in the Qur'an. Mufasir have different opinion about the meaning of the verse of mutasyâbihât al-lafdzi. In addition, many Hufadz of the Quran who are confused from one verse to another, or one chapter to another. It’s because similarity of verses in the Qur'an with other verses. So the writer wants to explain the verses mutasyâbihât al-lafdzi in the perspective of Hamzh al-Karmani in Surah al-An'âm. In this discussion the author discovers some passages in mutasyâbihât al-lafdzi, namely Asrâru al-balaghah fi mutasyabih al-lafdzi, Asrar al-balaghah fi mutasyabih al-hurf, and murâ'ah al-ikhtilâfmurâd bi al-lafdzi al-mukarrar.

  16. La responsabilidad social de las empresas

    DEFF Research Database (Denmark)

    Damgaard, Bodil

    El Instituto Nacional Danés de Investigación Social tiene actualmente un programa de investigación sobre la responsabilidad social de las empresas del cual el presente trabajo forma parte. Ante el cambio en los modelos económicos y las presiones que enfrentan los estados de bienestar, un...... crecimiento económico sostenible y equilibrado parece requerir, respecto a su modelo social, de alguna forma de bienestar polipartita (“welfare mix”). Empíricamente, se observan alteraciones en los sistemas de seguridad social en este sentido tanto en América Latina como en Europa Occidental durante las...... décadas más recientes. En el caso de América Latina, la tendencia ha sido transferir más responsabilidades a la sociedad civil, mientras que en Europa Occidental se ha buscado involucrar al sector civil y al sector empresarial. En este artículo se abordan los motivos de la Unión Europea para involucrar al...

  17. Desarrollo de un simulador de turbinas de gas fuera de diseño

    OpenAIRE

    Saiz Boned, Mercedes

    2016-01-01

    Este Trabajo Fin de Grado está englobado dentro de un conjunto de proyectos relacionados con la simulación y el estudio teórico de los ciclos de Turbina de Gas. Estos proyectos están siendo desarrollados dentro de la Unidad Docente de Motores Térmicos, perteneciente al Departamento de Ingeniería Energética de la Escuela Superior de Ingenieros Industriales de Madrid. Manuel Valdés del Fresno, tutor de este proyecto, ha sido la persona que ha guiado y seguido el desarrollo del proyecto desde...

  18. Diffusion-induced quadrupole relaxation of 27Al nuclei in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at high temperatures

    International Nuclear Information System (INIS)

    Bottyan, L.; Beke, D.L.; Tompa, K.

    1983-01-01

    The temperature dependence of the laboratory frame spin-lattice relaxation time of 27 Al nuclei is measured in 5N Al and in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at 5.7 and 9.7 MHz resonance frequencies. The relaxation in pure aluminium is found to be purely due to the conduction electrons. An excess T 1 -relaxation contribution is detected in all Al-3d alloys investigated above 670 K. The excess relaxation rate is proportional to the impurity content and the temperature dependence of the excess contribution is of Arrhenius-type with an activation energy of (1.3 +- 0.3) eV for all of the investigated alloys. The relaxation contribution is found to be quadrupolar in origin and is caused by the relative diffusional jumps of solute atoms and Al atoms relatively far from the impurity. (author)

  19. Interfacial phenomena in the reactions of Al-B, Al-Ti-B, and Al-Zr-B alloys with KF-AlF3 and NaF-AlF3 melts

    International Nuclear Information System (INIS)

    Lee, M.S.; Terry, B.S.; Grieveson, P.

    1993-01-01

    The interfacial phenomena occurring during the contacting of liquid Al-B, Al-Ti-B, and Al-Zr-B melts with KF-AlF 3 liquid fluxes have been investigated by optical examination of quenched metal drops previously immersed in the liquid fluxes. Reactions in the Al-B/KF-AlF 3 system involve the formation of metastable AlB 12 at the metal/flux interface. At high KBF 4 levels in the flux, the AlB 12 is dispersed in the flux and also at low KBF 4 levels in the metal. Reactions in the Al-Ti-B/KF-AlF 3 system involve the formation of TiB 2 , which may be dispersed in either the metal or the flux depending upon the composition of the flux. The results obtained for the Al-Ti-B/NaF-AlF 3 and Al-Zr-B/KF-AlF 3 systems were similar to those observed for the Al-Ti-B/KF-AlF 3 system

  20. Propuesta de comunicación entre unidades ganaderas

    Directory of Open Access Journals (Sweden)

    Raúl Erick Mederos Fundora

    2003-07-01

    Full Text Available Se estudiaron los protocolos que componen el estándar WAP, para mediante ellos resolver los problemas de información relacionados con los simuladores o browsers y con el servidor de servicios de Internet.  Como resultado se obtuvo un sitio Wap en el que se le brinda al productor la posibilidad de interactuar con datos del control técnico individual del ganado vacuno, almacenados en una base de datos remota.  Para el desarrollo de la aplicación se utilizó como lenguaje de programación el WML y para brindarle mayor potencialidad, se empleó el ASP.  Con la fusión de estos elementos se creó una interfaz que resultara lo más amigable posible para el usuario.

  1. Synthesizing (ZrAl3 + AlN)/Mg-Al composites by a 'matrix exchange' method

    Science.gov (United States)

    Gao, Tong; Li, Zengqiang; Hu, Kaiqi; Han, Mengxia; Liu, Xiangfa

    2018-06-01

    A method named 'matrix exchange' to synthesize ZrAl3 and AlN reinforced Mg-Al composite was developed in this paper. By inserting Al-10ZrN master alloy into Mg matrix and reheating the cooled ingot to 550 °C, Al and Mg atoms diffuse to the opposite side. As a result, liquid melt occurs once the interface areas reach to proper compositions. Then dissolved Al atoms react with ZrN, leading to the in-situ formation of ZrAl3 and AlN particles, while the Al matrix is finally replaced by Mg. This study provides a new insight for preparing Mg composites.

  2. Coupled growth of Al-Al2Cu eutectics in Al-Cu-Ag alloys

    International Nuclear Information System (INIS)

    Hecht, U; Witusiewicz, V; Drevermann, A

    2012-01-01

    Coupled eutectic growth of Al and Al 2 Cu was investigated in univariant Al-Cu-Ag alloys during solidification with planar and cellular morphology. Experiments reveal the dynamic selection of small spacings, below the minimum undercooling spacing and show that distinct morphological features pertain to nearly isotropic or anisotropic Al-Al 2 Cu interfaces.

  3. AL ITTIJAHAT AL MUNHARIFAH FI AT TAFSIR LI BADLI ASHAB AL MADZAHIB AL NAHWIYYAH WA BADL MAN YAJHALUNA QAWAID AL LUGHAH AL ARABIYYAH FI NADHAR MUHAMMAD HUSAIN AL DZAHABIY

    Directory of Open Access Journals (Sweden)

    Misbakhudin Misbakhudin

    2017-06-01

    Full Text Available One of the most precious achievement in qur’anic studies was the book of Al-Ittijâhât al-Munharifah fî al-Tafsîr: Dawâfi’uha wa Daf’uha written by A great Islamic scholar, Muhammad Husein al-Dzahabî. He was succeeded in discussing several issues of corruptions of the exegesis of the holy Qur’an. This article is aimed to explain and to describe his analysis toward several corrupted linguist interpretations in their originations and such corrupted linguistic interpretations of the holy Qur’an which are ignoring Arabic structures and grammers

  4. El proceso de inclusión laboral de los desmovilizados en la ciudad de Medellín y su Área Metropolitana

    Directory of Open Access Journals (Sweden)

    Jair Eduardo Restrepo Pineda

    2017-10-01

    Full Text Available Se realiza un análisis sobre los procesos de inclusión laboral de las personas desmovilizadas en la ciudad de Medellín y su Área Metropolitana, la cual concentra el mayor número de desmovilizados del país, con cerca de 5433 que se han reintegrado a la sociedad entre los años 2006 a 2016, según datos de la Agencia Colombiana para la Reintegración (ACR. Se evidenció que existen diversas barreras sociales, culturales y económicas que limitan el acceso al empleo por parte de los desmovilizados, entre ellas la estigmatización social, la baja oferta laboral, el desconocimiento de las habilidades del desmovilizado y las presiones de grupos al margen de la ley que pueden ocasionar el retorno de estas personas a los grupos armados ilegales

  5. ADVANTAGES AND THERMODYNAMIC LIMITATIONS OF THE EXPERIMENTAL SORPTION ISOSTERIC METHOD

    Directory of Open Access Journals (Sweden)

    FARID B. CORTÉS

    2013-01-01

    Full Text Available Una revisión de las ventajas y las limitaciones termodinámicas presentes en el método experimental sorción isostérica (SIM muestra que el SIM no garantiza una cantidad adsorbida constante. Las isósteras calculadas que consideran comportamiento de gas ideal muestran que en el SIM la masa de gas en el volumen muerto del sistema al incrementar la presión de equilibrio debido a los materiales desorbidos. El SIM es útil y efectivo para obtener datos termodinámicos de alta precisión para la sorción de gases en materiales micro y nanoporosos a bajas presiones y temperaturas. Por el contrario, cuando la presión y la temperatura son altas la desorción no es despreciable, por lo tanto el SIM no es aplicable. Los errores en los cálculos del calor isostérico usando SIM pueden ser reducidos usando procedimientos experimentales tradicionales como las isobaras e isotermas de adsorción para generar las isósteras a altas presiones y temperaturas. Como alternativa, correcciones por presión y temperatura, o un experimento que, después de cada incremento de temperatura permita a la dosis de gas compensar la masa desorbida, garantizaría una cantidad adsorbida constante y, por consiguiente, un comportamiento isostérico mediante medidas directas.

  6. Efecto de las altas presiones hidrostáticas respecto a la pasteurización térmica en los aspectos microbiológicos, sensoriales y estabilidad oxidativa de un paté de aceituna

    Directory of Open Access Journals (Sweden)

    Sánchez, J.

    2012-03-01

    Full Text Available The present study examines the effect of high hydrostatic pressure processing (HHP as an alternative to thermal pasteurization treatments for the conservation of olive pate and its stability during refrigerated storage, through the characterization of microbiological, physico-chemical and sensory aspects. The olive pate was made with green, pitted table olives packed in brine. Orange juice, olive oil, spices and potassium sorbate were added to the olives after being washed in water. To evaluate the effects of processing, four treatments of APH (450 and 600MPa for 5 and 10 min and a thermal pasteurization (80 °C for 20 min were applied to compare them with the unprocessed product. APH-treated samples showed a further reduction in the presence of microorganisms, an increase in oxidative stability, a higher sensory acceptance, greater clarity and less browning regarding the colorimetric coordinates, in comparison with those treated by thermal pasteurization. The study of the shelf life of the product in refrigeration would indicate the feasibility to implement APH technology in order to obtain food with a similar shelf life to foods obtained through the traditional thermal pasteurization treatment, but with better sensory quality.

    En el presente trabajo se valoró el efecto del procesado por altas presiones hidrostáticas (APH como método alternativo al tratamiento térmico de pasteurización para la conservación del paté de aceituna y su estabilidad durante el almacenamiento en refrigeración, mediante la caracterización de los aspectos microbiológicos, físico-químicos y sensoriales. El paté de aceituna fue elaborado partiendo de aceituna de mesa verde deshuesada y envasada en salmuera, a la cual, previo lavado con agua, se le adiciona zumo de naranja natural, aceite de oliva virgen, especias y sorbato potásico. Para evaluar el efecto del procesado, se aplicaron cuatro tratamientos de APH (450 y 600MPa durante 5 y 10min y otro de

  7. La hipertensión

    OpenAIRE

    Sainz, Jesús

    2016-01-01

    La hipertensión, también conocida como presión arterial alta o hipertensión arterial, es una condición médica crónica en la que se eleva la presión sanguínea en las arterias. La presión arterial se expresa mediante dos mediciones, las presiones sistólica y diastólica, que son las presiones máximas y mínimas, respectivamente, en el sistema arterial.

  8. Familial ALS

    Science.gov (United States)

    Boylan, Kevin

    2015-01-01

    Synopsis Genes linked to ALS susceptibility are being identified at an increasing rate owing to advances in molecular genetic technology. Genetic mechanisms in ALS pathogenesis appear to exert major effects in ~10% of patients, but genetic factors at some level may be important components of disease risk in most ALS patients. Identification of gene variants associated with ALS has informed concepts of the pathogenesis of ALS, aided the identification of therapeutic targets, facilitated research to develop new ALS biomarkers, and supported the establishment of clinical diagnostic tests for ALS-linked genes. Translation of this knowledge to ALS therapy development is ongoing. PMID:26515623

  9. 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.

  10. Transient oxidation of Al-deposited Fe-Cr-Al alloy foil

    International Nuclear Information System (INIS)

    Andoh, A.

    1997-01-01

    The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (θ-Al 2 O 3 , γ-Al 2 O 3 ). Scales consisting of θ-Al 2 O 3 and a small amount of α-Al 2 O 3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of θ-Al 2 O 3 and α-Al 2 O 3 grow rapidly on the Al-deposited foil. The transformation from θ-Al 2 O 3 to α-Al 2 O 3 is very fast, and the scales result in only α-Al 2 O 3 . In contrast, α-Al 2 O 3 scales containing a minor amount of FeAl 2 O 4 develop on the alloy foil. The growth rate of α-Al 2 O 3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

  11. Differences in the pressures of canal anal and rectal sensitivity in patients with fecal incontinence, chronic constipation and healthy subjects Diferencias en las presiones del canal anal y la sensibilidad rectal en pacientes con incontinencia anal, estreñimiento crónico y sujetos sanos

    Directory of Open Access Journals (Sweden)

    C. Ciriza de los Ríos

    2010-12-01

    Full Text Available Introduction: There exist a great variability in the manometric findings between patients with anal incontinence (AI and healthy subjects. The correlation between the pressures of the anal canal and the AI is not exact by the wide rank of normal values. Objectives: Prospective study to evaluate differences in the pressures of the anal canal and in rectal sensitivity in patients with AI, chronic constipation (CC and healthy subjects. Material and methods: Ninety four patients with AI, 36 patients with CC and 15 healthy subjects were included. The following data were obtained: age, sex, resting pressure, anal canal length (ACL, squeeze maximum pressure (SMP, squeeze pressure duration (SPD, first sensation, urge and maximum tolerated volume (MTV. Statistical study: test of Kruskal-Wallis, test of Mann-Whitney, and multinomial logistic regression test. Results: There were significant differences in the resting pressure (p Introducción: Existe gran variabilidad en los hallazgos manométricos entre pacientes con incontinencia anal (IA y sujetos sanos. La correlación entre las presiones del canal anal y la IA no es exacta por el amplio rango de valores normales. Objetivos: Estudio prospectivo para evaluar diferencias en las presiones del canal anal y en la sensibilidad rectal en pacientes con IA, estreñimiento crónico (EC y sujetos sanos. Material y métodos: Noventa y cuatro pacientes con IA, 36 pacientes con EC y 15 sujetos sanos. Se obtuvieron: edad, sexo, presión de reposo, longitud del canal anal (LCA, presión de máxima contracción voluntaria (PMCV, duración de la contracción voluntaria, primera sensación, sensación de urgencia y máximo volumen tolerado (MVT. Estudio estadístico: test de Kruskal-Wallis, test de Mann-Whitney, regresión logística multinomial. Resultados: Se encontraron diferencias significativas en la edad (p < 0,001, la presión de reposo (p < 0,001, la LCA (p < 0,001 y la PMCV (p < 0,01 en el grupo de IA con

  12. Proton irradiation studies on Al and Al5083 alloy

    Science.gov (United States)

    Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

    2017-10-01

    The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

  13. ENERGÍA DE ENLACE DE EXCITONES EN POZOS CUÁNTICOS DE GaAs/Ga1-xAl xAs

    Directory of Open Access Journals (Sweden)

    Parménides Aristizábal

    2007-06-01

    Full Text Available El uso de las estructuras de baja dimensionalidad es un elemento tecnológico clave en la creación de nuevos dispositivos cuánticos funcionales de la siguiente generación de circuitos integrados electrónicos, fotónicos y espintrónicos y muchos otros dispositivos nanotecnológicos que son necesarios para la sociedad de la información del siglo XXI. Una de las propiedades ópticas más importante es la fotoluminiscencia producida por agentes tales como impurezas y excitones en pozos, hilos y puntos cuánticos de arseniuro de galio GaAs con dimensiones nanométricas bajo la influencia de campos eléctricos y magnéticos y presiones externas. Se presenta la energía de enlace para los tres primeros estados excitónicos en pozos cuánticos de GaAs/Ga1-xAl xAs describiendo el sistema por medio de la teoría cuántica, en la aproximación de masa efectiva y usando el método variacional.The use of low dimensional structures is a key technological element in the creation of new quantum functional devices in the development of the next generation of the electronic, photonic, and spintronic integrated circuits and many other nanoscaled devices that are necessary for the information society of 21st century. One of the most important optical properties is the photoluminescence produced by agents as impurities and excitons in GaAs quantum wells, wires, and dots with nanometric dimensions under the influence of electric and magnetic fields and external pressures. The binding energy for the first three excitonic states in GaAs/Ga1-xA1xAs quantum wells describing the system through quantum theory in the effective mass approximation and using the variational method is presented.

  14. PEMBARUAN MASLAḤAH DALAM MAQĀṢID AL- SHARĪ‘AH: TELAAH HUMANISTIS TENTANG AL-KULLIYYĀT AL-KHAMSAH

    Directory of Open Access Journals (Sweden)

    Zaenuddin Mansyur

    2012-06-01

    Full Text Available Abstract:   In order to answer a variety of issues faced by human being in the current era, such as human rights abuses, social disintegration, and terrorism, the renewal of Islamic law in the level of theoretical and practical aspects is very urgent. This paper aims to examine one of the Islamic legal reform efforts, namely to build a more technical understanding of the concept of maṣlaḥah contained in the maqāṣīd sharī‘ah, called the al-kulliyat al-khamsah. Therefore, the concept of maṣlaḥah in ḥifẓ al-dīn is technically defined as al-ḥurriyah al-i‘tiqād (freedom of religion and schools; in ḥifẓ al-nafs as al-karamat al-insān (human being breeding; in ḥifẓ al-nasl as ḥifẓ al-usrah (wholeness and harmony of the family; in ḥifẓ al-māl as al-taḍammun al-insān (social solidarity , and in ḥifẓ al-‘aql as al-ḥuqūq as al-tarbiyāt (increasing human resources quality.Abstrak: Demi menjawab aneka persoalan zaman yang dihadapi manusia era sekarang, seperti penyelewengan terhadap HAM, disintegrasi sosial, dan terorisme, maka pembaharuan hukum Islam dalam tataran teoretis dan praktis urgen dilakukan. Tulisan ini bertujuan untuk mengkaji salah satu upaya pembaruan hukum Islam, yaitu membangun pemahaman yang lebih teknis terhadap konsep maṣlaḥah yang terkandung dalam maqāṣīd sharī‘ah, yang disebut dengan al-kulliyāt al-khamsah. Oleh karena itu, konsep maṣlaḥah dalam ḥifẓu al-dīn secara teknis dimaknai sebagai ḥurriyah al-i‘tiqād (kebebasan untuk beragama dan beraliran; dalam ḥifẓu al-nafs sebagai al-karāmāt al-insān (pemuliaan kemanusiaan; dalam ḥifẓu al-nasl sebagai ḥifẓu al-usrah (keutuhan dan keharmonisan keluarga; dalam ḥifẓu al-māl sebagai al-taḍammun al-insān (solidaritas sosial; dan dalam ḥifẓu al-‘aql sebagai al-ḥuqūq al-tarbiyāt (peningkatan sumber daya manusia.

  15. Combustion synthesis of AlB2-Al2O3 composite powders with AlB2 nanowire structures

    Science.gov (United States)

    Yang, Pan; Xiao, Guoqing; Ding, Donghai; Ren, Yun; Yang, Shoulei; Lv, Lihua; Hou, Xing

    2018-05-01

    Using of Al and B2O3 powders as starting materials, and Mg-Al alloy as additives, AlB2-Al2O3 composite powders with AlB2 nanowire structures were successfully fabricated via combustion synthesis method in Ar atmosphere at a pressure of 1.5 MPa. The effect of different amount of Mg-Al alloy on the phase compositions and morphology of the combustion products was investigated. The results revealed that AlB2 and Al2O3 increased, whereas Al decreased with the content of Mg-Al alloy increasing. The impurities MgAl2O4 and AlB12 would exist in the sample with adding of 18 wt% Mg-Al alloy. Interestingly, FESEM/TEM/EDS results showed that AlB2 nanowires were observed in the products when the content of Mg-Al alloy is 6 wt% and 12 wt%. The more AlB2 nanowires can be found as the content of Mg-Al alloy increased. And the yield of AlB2 nanowires with the diameter of about 200 nanometers (nm) and the length up to several tens of micrometers (μm) in the combustion product is highest when the content of Mg-Al alloy is 12 wt%. The vapor, such as Mg-Al (g), B2O2 (g), AlO (g) and Al2O (g), produced during the process of combustion synthesis, reacted with each other to yield AlB2 nanowires by vapor-solid (VS) mechanism and the corresponding model was also proposed.

  16. The effects of boron in TiAl/Ti3Al

    International Nuclear Information System (INIS)

    Feng, C.R.; Michel, D.J.; Crowe, C.R.

    1989-01-01

    The authors discuss the TiAl/Ti 3 Al interfacial misfit dislocations structures investigated by TEM in Ti-45Al alloy and Ti-45Al/TiB 2 composite. For TiAl with c/a = 1.02, only a single set of misfit dislocation arrays are crystallographically possible; these were observed in Ti-45Al alloy. However, the observation of three sets of misfit dislocation arrays in the Ti-45Al/TiB 2 composite suggests that the occupation of octahedral sites in the TiAl structure by excess boron was responsible for a decrease in the c/a ratio leading to an increased fcc character of the TiAl at the TiAl/Ti 3 Al interface

  17. 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

  18. 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.

  19. PEMAHAMAN HADITS TARBAWI BURHAN AL ISLAM AL ZARNUJI DALAM KITAB TA’LIM AL MUTA’ALLIM

    Directory of Open Access Journals (Sweden)

    Benny Afwadzi

    2017-01-01

    Full Text Available This paper explores the understanding of tarbawi (education hadith from one of the major influential clerics in the Islamic educational system, especially in pesantren. He is Burhan al Islam al Zarnuji with his landmark book Ta’lim al Muta’allim. The conclusion that can be drawn is that al Zarnuji has shades of sufistical view in understanding tarbawi hadith. This can be seen in his understanding of hadith on obligation to seek knowledge (thalab al ilmi faridhatun ‘ala kulli muslimin wa muslimatin, which is interpreted as ilm al hal, the science concerning the condition of the human religious or simplistically said as the religious sciences; and the hadith of intention of studying (innama al a’malu bi al niyyat with the intention for the sake of the hereafter and religion, not mundane. Such an understanding is not something taken for granted, but it can be reinterpreted and perfected in accordance with the spirit of the times of context.

  20. Situación didáctica del concepto de derivada

    OpenAIRE

    Camacho, Alberto; Sánchez, Bertha Ivonne

    2004-01-01

    Proponemos introducir el concepto de derivada mediante una aplicación de la velocidad media, utilizando un simulador y el desarrollo en serie de funciones, a partir de lo cual los estudiantes proporcionen una definición de la derivada.

  1. Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model

    International Nuclear Information System (INIS)

    Li, H.Q.; Yang, Y.S.; Tong, W.H.; Wang, Z.Y.

    2007-01-01

    With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni . To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

  2. Nuevas relaciones laborales en la industria automotriz colombiana

    OpenAIRE

    Edgar Augusto Valero

    2004-01-01

    Los sectores de ensamble de autos y fabricación de autopartes en Colombia describen las presiones que ejerce el entorno competitivo internacional sobre la eficiencia y la calidad. Estas presiones han incidido en la adopción de nuevas formas de organización del trabajo y en el cambio casi generalizado de políticas de personal durante los últimos quince años. En este artículo se analiza e ilustra un conjunto de transformaciones significativas en las relaciones laborales en esta rama industrial,...

  3. Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

    International Nuclear Information System (INIS)

    Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

    2013-01-01

    Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

  4. The code of light: al-ghazali and al-suhrawardi

    OpenAIRE

    Gediminaitė, Barbora

    2017-01-01

    The Code of Light: Al-Ghazali and Al-Suhrawardi The Bachelor’s thesis The Code of Light in Islam: al-Ghazali and al-Suhrawardi presents a comparative study of light. The study analyses the philosophical systems of al-Ghazali and al-Suhrawardi through the reconstruction of the image of light and its operation principles. The main subject of the thesis are the attributes of light. The main problem of the research is the semantics and contextuality of light in Islamic theology and philosophy. Th...

  5. Pemikiran Filosofis Sadra Dalam Tafsir Al-Qur’an Al-Karim : Surah Al-’A‘la

    Directory of Open Access Journals (Sweden)

    Kerwanto Kerwanto

    2014-12-01

    Full Text Available Abstrak : Dalam tafsir atas Surah al-’A‘lā, Mulla Sadra, melalui karyanya Tafsīr al Qur’ān al-Karīm, mengajak jiwa kita berpetualang menuju lapisan makna terdalam untuk mengenali realitas ketauhidan (al- mabdā’, kenabian (shirāth atau nubuwwah dan kebangkitan (ma‘ād dan mengulasnya secara filosofis. Penelitian ini merupakan suatu upaya untuk menggali manfaat dari aspek-aspek penting dari sumber-sumber keagamaan yang tergali dari petunjuk al Qur’an yang berpadu dengan prinsip- prinsip rasional filosofis dan pengalaman mistik (intuitif Sadra. Setiap bab pada tafsir ini diberikan judul dengan tasbīḥ (pernyataan pemujian dan pensucian, dengan tetap memaparkan beragam pokok persoalan terkait metafisika al-Qur’an. Prinsip-prinsip filosofis yang digunakan dalam risalah tafsir ini bisa menjadi salah satu bukti ketidakberjarakan antara filsafat dengan teks-teks keagamaan. Sadra menggunakan metode tafsir yang tetap menerima sisi lahiriah al-Qur’an, dan selanjutnya mencari misteri-misteri, rahasia-rahasia, dan dengan bantuan intelek (akal, intuisi dan iluminasi Tuhan untuk memperoleh realitas-realitas dan makna- makna dibalik selaput ekternalnya (aspek literalnyaKata kunci : Ḥikmah Muta’āliyah, irfan, al-mabdā’, kebangkitan setelah mati, nubuwwah, takwīl, gerak substansial (ḥarakah jawhariyyah, denotasi utama (al-maqshūd al-ashlī, penyempurnaan diri (takammul, tasbīḥ.  Abstract : In his commentary on Surah al-’ A‘lā, Mulla Sadra, through his Tafsīr al-Qur’ān al-Karīm invites our souls to ventureinto the deepest layers of meaning to recognize the reality of Divinity (al- mabdā’, prophethood (Ṣirāṭ or nubuwwah and resurrection (ma‘ād and discusses it in a more philosophical manner. This study is an attempt to explore the benefits of these important aspects of religious sources unearthed from Qur’anic injunctions combined with rational principles of philosophical and mystical experiences

  6. A united refinement technology for commercial pure Al by Al-10Ti and Al-Ti-C master alloys

    International Nuclear Information System (INIS)

    Ma Xiaoguang; Liu Xiangfa; Ding Haimin

    2009-01-01

    Because flake-like TiAl 3 particles in Al-Ti-C master alloys prepared in a melt reaction method dissolve slowly when they are added into Al melt at 720 deg. C, Ti atoms cannot be released rapidly to play the assistant role of grain refinement, leading to a poor refinement efficiency of Al-Ti-C master alloys. A united refinement technology by Al-10Ti and Al-Ti-C master alloys was put forward in this paper. The rational combination of fine blocky TiAl 3 particles in Al-10Ti and TiC particles in Al-Ti-C can improve the nucleation rate of α-Al. It not only improves the grain refinement efficiency of Al-Ti-C master alloys, but also reduces the consumption

  7. Liquidus projection of the Nb-Cr-Al system near the Al3(Nb,Cr) + Cr(Al,Nb) eutectic region

    International Nuclear Information System (INIS)

    Souza, S.A.; Ferrandini, P.L.; Nunes, C.A.; Coelho, A.A.; Caram, R.

    2006-01-01

    The system Nb-Cr-Al was investigated in the region near the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic and the liquidus projection of that region was determined based on the microstructural characterization of arc melted alloys. The characterization utilized scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results allowed one to determine three primary solidification liquidus surfaces ((Cr,Al) 2 Nb, Cr(Al,Nb) and Al 3 (Nb,Cr)), that are originated from the binary systems Cr-Nb, Cr-Al and Al-Nb. It is proposed the occurrence of the invariant reaction L + (Cr,Al) 2 Nb ↔ Al 3 (Nb,Cr) + Cr(Al,Nb) and of a point of minimum, which involves a three phase reaction, L ↔ Al 3 (Nb,Cr) + Cr(Al,Nb). All alloys studied showed formation of the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic as the last solidification step with Al(Nb)Cr 2 precipitating from Cr(Al,Nb)

  8. A united refinement technology for commercial pure Al by Al-10Ti and Al-Ti-C master alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ma Xiaoguang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)], E-mail: xfliu@sdu.edu.cn; Ding Haimin [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China)

    2009-03-05

    Because flake-like TiAl{sub 3} particles in Al-Ti-C master alloys prepared in a melt reaction method dissolve slowly when they are added into Al melt at 720 deg. C, Ti atoms cannot be released rapidly to play the assistant role of grain refinement, leading to a poor refinement efficiency of Al-Ti-C master alloys. A united refinement technology by Al-10Ti and Al-Ti-C master alloys was put forward in this paper. The rational combination of fine blocky TiAl{sub 3} particles in Al-10Ti and TiC particles in Al-Ti-C can improve the nucleation rate of {alpha}-Al. It not only improves the grain refinement efficiency of Al-Ti-C master alloys, but also reduces the consumption.

  9. Simulación de Plataformas Robóticas de Movimiento para Aplicaciones de Realidad Virtual Mediante Filtros Digitales

    Directory of Open Access Journals (Sweden)

    Sergio Casas

    2017-10-01

    Full Text Available Resumen: El uso de plataformas robóticas de movimiento en simuladores de vehículos y aplicaciones de Realidad Virtual es relativamente habitual. Sin embargo, el ajuste de los algoritmos que controlan su funcionamiento, denominados algoritmos de washout, no es sencillo y requiere de numerosas pruebas hasta obtener una apropiada fidelidad de movimiento. Disponer de herramientas que permitan simular plataformas de movimiento puede permitir simplificar esta tarea. Es por ello que este trabajo presenta un método para la caracterización y simulación de manipuladores robóticos mediante filtros digitales de segundo orden, sencillo de implementar y ajustar a partir de una caracterización previa. El simulador se construye con el objetivo de permitir la simulación rápida de manipuladores robóticos y se ejemplifica con una plataforma de dos grados de libertad, aunque el método propuesto podría emplearse en otros dispositivos. En las pruebas realizadas se valida la precisión y velocidad de la simulación, concluyéndose que se obtiene una fidelidad satisfactoria y una velocidad de simulación elevada que permite emplear el simulador como sustituto del hardware real con algoritmos de washout. Abstract: Robotic motion platforms are used in many vehicle simulators and Virtual Reality applications. However, the set-up of the so-called washout algorithms that control the generation of self-motion is a hard process, since a great deal of tests need to be performed before reaching a proper motion fidelity. The availability of simulation tools eases this tuning task. Therefore, a motion platform characterization and simulation method is proposed in this paper. The method relies on second order digital filters and provides a reliable, yet very fast simulation system, which is assessed by means of a two degree-of-freedom motion platform, although the method might be applied to simulate other motion mechanisms. Palabras clave: Plataformas de movimiento

  10. 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.

  11. Nanoporous Al sandwich foils using size effect of Al layer thickness during Cu/Al/Cu laminate rolling

    Science.gov (United States)

    Yu, Hailiang; Lu, Cheng; Tieu, A. Kiet; Li, Huijun; Godbole, Ajit; Kong, Charlie

    2018-06-01

    The roll bonding technique is one of the most widely used methods to produce metal laminate sheets. Such sheets offer interesting research opportunities for both scientists and engineers. In this paper, we report on an experimental investigation of the 'thickness effect' during laminate rolling for the first time. Using a four-high multifunction rolling mill, Cu/Al/Cu laminate sheets were fabricated with a range of thicknesses (16, 40, 70 and 130 μm) of the Al layer. The thickness of the Cu sheets was a constant 300 μm. After rolling, TEM images show good bonding quality between the Cu and Al layers. However, there are many nanoscale pores in the Al layer. The fraction of nanoscale pores in the Al layer increases with a reduction in the Al layer thickness. The finite element method was used to simulate the Cu/Al/Cu rolling process. The simulation results reveal the effect of the Al layer thickness on the deformation characteristics of the Cu/Al/Cu laminate. Finally, we propose that the size effect of the Al layer thickness during Cu/Al/Cu laminate rolling may offer a method to fabricate 'nanoporous' Al sandwich laminate foils. Such foils can be used in electromagnetic shielding of electrical devices and noisy shielding of building.

  12. Structural stability and electronic properties of AlCu3, AlCu2Zr in AlZr3: Stabilnost strukture in elektronske lastnosti AlCu3, AlCu2Zr in AlZr3:

    OpenAIRE

    Cheng, Rong; Wu, Xiao-Yu

    2013-01-01

    First-principles calculations were performed to study the alloying stability and electronic structure of the Al-based intermetallic compounds AlCusub3, AlCusub{2}Zr and AlZrsub3. The results show that the lattice parameters obtained after the full relaxation of the crystalline cells are consistent with the experimental data, and these intermetallics have a strong alloying ability and structural stability due to their negative formation energies and their cohesive energies. A further analysis ...

  13. Superplastic forming of the Cd-17.4Zn alloy; Conformado superplastico de la aleacion Cd-17.4Zn

    Energy Technology Data Exchange (ETDEWEB)

    Llanes-Briceno, J. A.; Torres-Villasenor, G. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-06-01

    In the present work the necessary steps to carry on the superplastic forming of the Cd-17.4Zn alloy are defined. The use of either atmospheric pressure or gas pressure as forming tools is analyzed. The optimum values of the variable involved (temperature, maximum strain and sensitivity index) are determined while a method for the characterization of futures superplastic alloys is set forth. The experimental characterization of the superplastic forming is achieved with free bulging of circular membranes of 12, 16, 24, 32 and 40 mm in diameter and with three different membrane thicknesses (0.4, 0.6, 0.8 mm). [Spanish] Se definen los pasos necesarios para el conformado superplastico de la aleacion Cd-17.4 Zn. Se comparan la presion atmosferica y el gas a presion como herramientas de conformado. Se determinan los valores optimos de la variables involucradas (temperatura, deformacion maxima e indice de sensibilidad) y se plantea una metodologia para la caracterizacion de futuras aleaciones superplasticas. El conformado superplastico se caracteriza experimentalmente mediante el inflado libre de membranas circulares de 12, 16, 24, 32 y 40 mm de diametro y tres diferentes espesores (0.4, 0.6 y 0.8 mm). Se muestra la estructura perlitica (enfuiada al aive Cd-17.4Zn) y la estructura grano fino. Se muestra la profundidad de deformacion en tres espesores (0.4, 0.6, 0.8 mm) a P=200 Kpa y T = 200 y a T = 230.

  14. SIMULACIÓN ESTACIONARIA DE UN EVAPORADOR DE DOBLE EFECTO PARA JUGO DE TOMATE

    Directory of Open Access Journals (Sweden)

    Álvaro Núñez

    2012-01-01

    Full Text Available En este trabajo se desarrolló un modelo estacionario para simular un sistema evaporador de doble efecto destinado a la concentración de jugo de tomate. Debido a que el licopeno muestra capacidad antioxidante, es deseable que su concentración sea máxima en la pasta de tomate. Ello se logra optimizando tanto el diseño como las condiciones de operación del equipo concentrador de jugo. Para alcanzar ese objetivo, se incorporó al modelo la cinética de degradación del licopeno, y se realizó un estudio de sensibilidad para determinar las relaciones que vinculan las variables de proceso. El estudio determinó que el contenido de licopeno en el producto es altamente sensible al tiempo de residencia; mientras que el consumo de vapor está determinado por la presión del vapor de servicio y las presiones de los efectos.

  15. /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.

  16. Metodologi Kitab Ma‘alim al-Tanzil Karya Al-Bagawiy

    Directory of Open Access Journals (Sweden)

    M. Rusydi Khalid

    2017-12-01

    This study aims to describe the metodology of Ma'a> lim al-tanzi>l book by al-Bagawi. The book is one of the books of exegesis written on the basis of hadith, which by the commentary scholars recognized avoided from heresy and weak hadith. The author of this book is Imam Abu Humaid Hussein bin Mas‘u>d al-Farra>’ Al-Bagawi al-Syafi‘i>, died in the year 510 H. This exegesis book combines the interpretation of the companions, tabi‘i>n, and tabi‘i> tabi‘i>n. Interpretation is broken down with easy, simple, and concise diction choices. The stoning of the interpretation of the salaf scholars without mentioning the sanad as already mentioned in the introduction to his book. This book was first printed in one edition with the exegesis book of Ibn Kas}i>r and al-kha>zin. This book interprets the Qur'an analytically from the beginning to the end of the surah by using the method of interpretation based on the hadith, namely by mentioning the arguments of the hadith sahih, the fatwa of the companions and the tabi‘i>n. The characteristic or purpose of this book is fiqh oriented, which tends to the Shafi‘i fiqh.   Abstrak Tulisan ini mendeskripsikan metode penafsiran dalam kitab Ma’a>lim al-tanzi>l karya al-bagawi. Kitab tafsir ini merupakan salah satu di antara kitab-kitab tafsir yang ditulis berdasarkan riwayat, yang oleh para ulama tafsir diakui terhindar dari bid’ah dan hadis dhaif (lemah. Penulis buku ini adalah Imam Abu Muhammad Husain bin Mas‘u>d al-Farra>‘ al-Bagawi al-Syafi‘i>, wafat pada tahun 510 H. Kitab ini adalah kitab pertengahan yang mengutip penafsiran para Sahabat, ta>bi‘i>n, dan tabi‘i ta>bi‘i>n. Penafsiran diuraikan dengan pilihan diksi yang mudah, sederhana, dan ringkas. Penukilan dari interpretasi ulama salaf tanpa menyebutkan sanad karena telah disebutkan dalam pendahuluan bukunya. Buku ini pertama kali dicetak dalam satu edisi dengan tafsir Ibn Kas\\i>r dan tafsir al-Kha>zin. Kitab ini menafsirkan al-Qur’an secara

  17. ALS Association

    Science.gov (United States)

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  18. Implementació d'un Tesselador de DirectX 11 per una targeta gràfica

    OpenAIRE

    Ramírez Guerrero, Daniel

    2012-01-01

    El objetivo del proyecto es efectuar un estudio sobre la etapa de teselación de DirectX 11 y ofrecer una implementación de una versión muy básica en el simulador de tarjetas gráficas del proyecto ATTILA.

  19. AlN nanoparticle-reinforced nanocrystalline Al matrix composites: Fabrication and mechanical properties

    International Nuclear Information System (INIS)

    Liu, Y.Q.; Cong, H.T.; Wang, W.; Sun, C.H.; Cheng, H.M.

    2009-01-01

    To improve the specific strength and stiffness of Al-based composites, AlN/Al nanoparticles were in-situ synthesized by arc plasma evaporation of Al in nitrogen atmosphere and consolidated by hot-pressing to fabricate AlN nanoparticle-reinforced nanocrystalline Al composites (0-39 vol.% AlN). Microstructure characterization shows that AlN nanoparticles homogeneously distribute in the matrix of Al nanocrystalline, which forms atomically bonded interfaces of AlN/Al. The hardness and the elastic modulus of the nanocomposite have been improved dramatically, up to 3.48 GPa and 142 GPa, respectively. Such improvement is believed to result from the grain refinement strengthening and the interface strengthening (load transfer) between the Al matrix and AlN nanoparticles

  20. Comparison of one and two-neutron transfer near the Coulomb barrier for the 27Al(18O, 16O)29Al, 27Al(18O, 17O)28Al and 27Al(13C, 12C)28Al reactions

    International Nuclear Information System (INIS)

    Schiller, S.A.; Eck, J.S.

    1975-01-01

    Total reaction cross sections for the transfer reactions 27 Al( 18 O, 16 O) 29 Al, 27 Al( 18 O, 17 O) 28 Al and 27 Al( 13 C, 12 C) 28 Al are reported for center-of-mass energies between 13 and 20 MeV for 18 O projectiles and between 11 and 17.5 MeV for 13 C projectiles. The reaction products, 29 Al, and 28 Al, beta decay to 29 Si and 28 Si, respectively, and the subsequent γ decays of 29 Si and 28 Si were measured. Due to the relatively long beta decay half lives, data were taken in a beam-off mode, resulting in very clean spectra. Total cross sections were calculated and compared with a theoretical model for barrier penetration proposed by C.Y. Wong. Differences between 18 O induced one and two-neutron total transfer reaction cross sections are discussed. (orig.) [de

  1. Análisis de puntos de rocío y contenidos de humedad de mezclas gaseosas N2-H2O y CH4-H2O

    OpenAIRE

    D. Bogoya M.; C. Müller, I. Q.; L. R. Oellrich

    1995-01-01

    EI conocimiento actual del contenido de humedad de mezclas gaseosas saturadas es aún incompleto, especialmente en la región de altas presiones y bajas temperaturas. Por tanto se realizaron medidas experimentales de punta de rocío con los sistemas nitrógeno-agua y metano-agua, a presiones de 3 y 6 MPa y a temperaturas de 258 K a 288 K. Los puntos de rocío se determinaron con el método del espejo de punta de rocío y los contenidos de humedad por medio de la titulación de Karl-Fischer. Los valor...

  2. Al-matrix composite materials reinforced by Al-Cu-Fe particles

    International Nuclear Information System (INIS)

    Bonneville, J; Laplanche, G; Joulain, A; Gauthier-Brunet, V; Dubois, S

    2010-01-01

    Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ω-Al0 0.70 Cu 0.20 Fe 0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/ω, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particular in yield stress values. In the low temperature regime (T ≤ 570K), the yield stress of the Al/ω composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

  3. Piezo-tunnel effect in Al/Al2O3/Al junctions elaborated by atomic layer deposition

    Science.gov (United States)

    Rafael, R.; Puyoo, E.; Malhaire, C.

    2017-11-01

    In this work, the electrical transport in Al/Al2O3/Al junctions under mechanical stress is investigated in the perspective to use them as strain sensors. The metal/insulator/metal junctions are elaborated with a low temperature process (≤200 °C) fully compatible with CMOS back-end-of-line. The conduction mechanism in the structure is found to be Fowler-Nordheim tunneling, and efforts are made to extract the relevant physical parameters. Gauge factors up to -32.5 were found in the fabricated devices under tensile stress. Finally, theoretical mechanical considerations give strong evidence that strain sensitivity in Al/Al2O3/Al structures originates not only from geometrical deformations but also from the variation of interface barrier height and/or effective electronic mass in the tunneling oxide layer.

  4. 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.

  5. Convergencia de Los Mapas Conceptuales, las TIC y el e-learning en el proceso de enseñanza-aprendizaje.

    Directory of Open Access Journals (Sweden)

    Lydia Rosa Ríos Rodríguez

    2006-10-01

    Full Text Available Este artículo trata sobre los beneficios que aportan las tecnologías de la Informática, las comunicaciones, los mapas conceptuales y el e-learning al proceso de enseñanza – aprendizaje. Destaca al desarrollo de los sistemas de enseñanza asistidas por computadoras, desde los programas lineales hasta los actuales software educativos de enseñanza a distancia, el aporte que las técnicas de inteligencia artificial, internet, los foros de especialistas (como espacio abierto para la difusión de trabajos de investigación sobre temas específicos, las video conferencias interactivas, el uso de entrenadores, tutoriales inteligentes, simuladores, videos y otros medios que hacen más fácil la adquisición del conocimiento. Por ultimo se propone una herramienta: Software educativo de enseñanza a distancia “Mapa Conceptual del tema Programación Lógica”, que se está confeccionando por el grupo de desarrollo del software para la enseñanza, el cual ayudará a suplir las carencias (intelectuales y materiales que surjan en el país.

  6. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Radiation detection with Nb/Al-AlOx/Al/Nb superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Matsumura, Atsuki; Takahashi, Toru; Kurakado, Masahiko

    1992-01-01

    Superconductor radiation detectors have the possibility of 20-30 times better energy resolution than that of a high resolution Si detector. We fabricated Nb/Al-AlOx/Al/Nb superconducting tunnel junctions with low leakage current. X rays were detected with large area junctions of 178x178 μm 2 . High energy resolution of 160 eV for 5.9 keV was obtained. We also fabricated series connected junctions which covers a rather large area of 4x4 mm 2 . α particles injected into the rear substrate were detected using nonthermal phonons induced by the radiations in the substrate. (author)

  8. 18. Síndrome compartimental en una niña de 8 años secundario a canulación femoral para bypass cardiopulmonar

    Directory of Open Access Journals (Sweden)

    R. Maseda Uriza

    2010-01-01

    La isquemia de las extremidades inferiores secundaria a canulación de vasos femorales es poco frecuente, pocos casos en la literatura publicados. Se produce secundario al edema producido por la isquemia. Debe ser sospechada y tratada de forma precoz pues puede provocar contractura isquémica, pérdida de funcionalidad, rabdomiólisis y daño cerebral secundario. El diagnóstico precoz es difícil en un paciente sedado e intubado, la pérdida de pulsos es un signo tardío, precede a la pérdida irreversible de la extremidad, se debe sospechar en cualquier paciente sometido a canulación femoral y medir presiones tisulares para confirmar diagnóstico y actuar en consecuencia.

  9. Aprendizajes y encrucijadas del periodismo. Entre la Paz de Pastrana y la seguridad democrática de Uribe

    Directory of Open Access Journals (Sweden)

    Fabio López de la Roche

    2005-01-01

    Full Text Available El autor hace un profundo análisis sobre los aciertos y errores de los medios de comunicación al informar sobre el conflicto armado y los procesos de paz que se han llevado a cabo en Colombia. Presenta, en una primera parte, una visión sintética del periodismo en el proceso de paz con las FARC entre 1999 y 2002, poniendo especial atención a la relación con las fuentes de información acerca de la guerra. Una segunda parte analiza los problemas y riesgos del cubrimiento periodístico del conflicto en el contexto de la seguridad democrática del presidente Uribe y de sus presiones por redefinirlo semánticamente.

  10. Acción colectiva y conflicto de intereses: el caso de la comunidad campesina de Catac

    Directory of Open Access Journals (Sweden)

    Serafín Osorio Bautista

    2013-12-01

    Full Text Available Este artículo se propone la comprensión de los cambios en la comunidad de Catac como resultado de la acción colectiva ante los desafíos del contexto que se configuran como oportunidades y restricciones, y frente a las exigencias internas que se expresan como demandas de los grupos de interés o facciones que conforman la comunidad. En una comunidad heterogénea como Catac, la acción colectiva no es algo que se da por supuesto sino una acción deliberada; sin embargo, tiende a ser frágil y generalmente se rompe ante las presiones externas y las relaciones de poder definidas en términos de facciones al interior de la comunidad.

  11. ALS-Plus Syndrome: Non-Pyramidal Features in a Large ALS Cohort

    Science.gov (United States)

    McCluskey, Leo; Vandriel, Shannon; Elman, Lauren; Van Deerlin, Vivianna M.; Powers, John; Boller, Ashley; Wood, Elisabeth McCarty; Woo, John; McMillan, Corey T.; Rascovsky, Katya; Grossman, Murray

    2014-01-01

    Objective Autopsy studies show widespread pathology in amyotrophic lateral sclerosis (ALS), but clinical surveys of multisystem disease in ALS are rare. We investigated ALS-Plus syndrome, an understudied group of patients with clinical features extending beyond pyramidal and neuromuscular systems with or without cognitive/behavioral deficits. Methods In a large, consecutively-ascertained cohort of 550 patients with ALS, we documented atypical clinical manifestations. Genetic screening for C9orf72 hexanucleotide expansions was performed in 343 patients, and SOD1, TARDBP, and VCP were tested in the subgroup of patients with a family history of ALS. Gray matter and white matter imaging was available in a subgroup of 30 patients. Results Seventy-five (13.6%) patients were identified with ALS-Plus syndrome. We found disorders of ocular motility, cerebellar, extrapyramidal and autonomic functioning. Relative to those without ALS-Plus, cognitive impairment (8.0% vs 2.9%, p=0.029), bulbar-onset (49.3% vs 23.2%, pALS-Plus. Survival was significantly shorter in ALS-Plus (29.66 months vs 42.50 months, p=0.02), regardless of bulbar-onset or mutation status. Imaging revealed significantly greater cerebellar and cerebral disease in ALS-Plus compared to those without ALS-Plus. Conclusions ALS-Plus syndrome is not uncommon, and the presence of these atypical features is consistent with neuropathological observations that ALS is a multisystem disorder. ALS-Plus syndrome is associated with increased risk for poor survival and the presence of a pathogenic mutation. PMID:25086858

  12. Tailoring ultrafine grained and dispersion-strengthened Ti 2 AlC/TiAl ...

    Indian Academy of Sciences (India)

    In situ Ti 2 AlC/TiAl composite was fabricated by hot-pressing method via the reaction system of Ti 3 AlC 2 and Ti-Al pre-alloyed powders at low temperature of 1150 ∘ C. The composite mainly consisted of TiAl, Ti 3 Al and Ti 2 AlC phases. Fine Ti 2 AlC particles were homogeneously distributed and dispersed in the matrix.

  13. Assessing behavioural changes in ALS: cross-validation of ALS-specific measures.

    Science.gov (United States)

    Pinto-Grau, Marta; Costello, Emmet; O'Connor, Sarah; Elamin, Marwa; Burke, Tom; Heverin, Mark; Pender, Niall; Hardiman, Orla

    2017-07-01

    The Beaumont Behavioural Inventory (BBI) is a behavioural proxy report for the assessment of behavioural changes in ALS. This tool has been validated against the FrSBe, a non-ALS-specific behavioural assessment, and further comparison of the BBI against a disease-specific tool was considered. This study cross-validates the BBI against the ALS-FTD-Q. Sixty ALS patients, 8% also meeting criteria for FTD, were recruited. All patients were evaluated using the BBI and the ALS-FTD-Q, completed by a carer. Correlational analysis was performed to assess construct validity. Precision, sensitivity, specificity, and overall accuracy of the BBI when compared to the ALS-FTD-Q, were obtained. The mean score of the whole sample on the BBI was 11.45 ± 13.06. ALS-FTD patients scored significantly higher than non-demented ALS patients (31.6 ± 14.64, 9.62 ± 11.38; p ALS-FTD-Q was observed (r = 0.807, p ALS-FTD-Q. Good construct validity has been further confirmed when the BBI is compared to an ALS-specific tool. Furthermore, the BBI is a more comprehensive behavioural assessment for ALS, as it measures the whole behavioural spectrum in this condition.

  14. Plastic deformation of Al13Fe4 particles in Al-Al13Fe4 by high-speed compression

    International Nuclear Information System (INIS)

    Yoneyama, N.; Mizoguchi, K.; Kumai, S.; Sato, A.; Kiritani, M.

    2003-01-01

    Spray-formed Al-Fe alloys having undergone high-speed deformation were examined under a high-voltage electron microscope. Two types of specimens were examined; one containing fine Al 13 Fe 4 particles, and the other containing large particles. In the former specimen, deformation is found to proceed in three patterns, depending on specimen thickness and strain rate: (1) without deformation of the Al 13 Fe 4 ; (2) breaking of the Al 13 Fe 4 ; or (3) melting of the Al 13 Fe 4 . Local melting is found to alter some of the Al 13 Fe 4 particles, to impart five-fold symmetry in diffraction or an amorphous structure. In the latter specimen, introduction of glide dislocations enabled us to determine a shear system in the mc102 monoclinic c2/m crystal of Al 13 Fe 4 . On the bases of these observations, the mechanism of high-speed deformation is discussed while taking into account the highly stressed and/or heated states of Al 13 Fe 4 embedded in Al matrix

  15. Synthesis and characterization of pillared bentonite with Al, AL/Fe and impregnated with Pd; Sintese e caracterizacao de bentonitas pilarizadas com Al, AL/Fe e impregnadas com Pd

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcus Vinicius Costa; Pizarro, Alejandro Herrero; Molina, Carmen Belen, E-mail: marcus.ufpa@yahoo.com.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Instituto de Tecnologia. Faculdade de Engenharia Quimica; Seccion de Ingenieria Quimica, Facultad de Ciencias, Universidad Autonoma de Madri (Spain)

    2017-10-01

    In this work, a north american bentonite was pillared with Al and Al/Fe, creating the Al-PILC and Al-Fe-PILC, respectively. Then the Pd was impregnated in the materials, generating Pd-Al-PILC and Pd-Al-Fe-PILC, respectively. The samples were characterized by X-ray diffraction, differential thermal analysis and thermogravimetric and N{sub 2} adsorption at 77 K to determine the specific surface area by BET method (Brunauer - Emmett - Teller). There was an increase in the basal spacing of bentonite from 12.4Å in the original sample to 17.81Å in the Al-Fe-PILC, 17.20Å in Pd-Al-PILC and 17.05Å in the Pd-Al-Fe-PILC. The specific surface area increased from 19.05m{sup 2}/g in the original sample to 173.49m{sup 2}/g in Al-Fe-PILC, 101.31m{sup 2}/g to Pd-Al-PILC and 92m{sup 2}/g in Pd-Al-Fe-PILC. The pillaring process was successful and the synthesized materials have great potential for use as catalysts. (author)

  16. 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.

  17. Orientation of Al3Ti platelets in Al-Al3Ti functionally graded material manufactured by centrifugal method

    International Nuclear Information System (INIS)

    Watanabe, Y.; Fukui, Y.

    1997-01-01

    Al-Al 3 Ti functionally graded materials (FGMs) were manufactured by the centrifugal method with a commercial ingot of Al-5 mass% Ti master alloy. The alloy was melted at a liquid/solid coexisting temperature, at which Al 3 Ti remains as a solid, and then it was cast into a thick-walled ring. It was found that the Al-Al 3 Ti functionally graded material can be successfully fabricated by the centrifugal method. It was also found that the volume fraction of the Al 3 Ti can be increased by repetition of the centrifugal method. Since the shape of Al 3 Ti particles in a commercial alloy ingot is that of a platelet, the Al 3 Ti particles are arranged with their platelet planes nearly perpendicular to the radial direction. The orientation effects become stronger when the G number becomes larger. Although the final centrifugal casting was conducted under a very large centrifugal force for the specimen cast three times, the orientation effects were weaker than those in the specimen cast one time. From these observations, it is concluded that the origin of orientation of Al 3 Ti platelets can be attributed to the angular velocity gradient of the melt along the radial direction produced by the difference in the viscosity. (orig.)

  18. In situ synthesis of Ti{sub 2}AlC–Al{sub 2}O{sub 3}/TiAl composite by vacuum sintering mechanically alloyed TiAl powder coated with CNTs

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian [Department of Materials Science and Engineering of Tianjin University, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Zhao, Naiqin, E-mail: nqzhao@tju.edu.cn [State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin (China); Department of Materials Science and Engineering of Tianjin University, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Nash, Philip [Thermal Processing Technology Center, Illinois Institute of Technology, IL (United States); Liu, Enzuo; He, Chunnian; Shi, Chunsheng; Li, Jiajun [Department of Materials Science and Engineering of Tianjin University, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China)

    2013-11-25

    Highlights: •Using zwitterionic surfactant to enhance the dispersion of the CNTs on the powder surface. •CNTs as carbon source decreased the formation temperature of Ti{sub 2}AlC. •Al{sub 2}O{sub 3} was generated in situ from the oxygen atoms introduced in the drying procedure. •Nanosized Ti{sub 3}Al was precipitated at 1250 °C and distribute in the TiAl matrix homogeneously. •Ti{sub 2}AlC–Al{sub 2}O{sub 3}/TiAl composite was synthesized in situ by sintering pre-alloy Ti–Al coated with CNTs. -- Abstract: Bulk Ti{sub 2}AlC–Al{sub 2}O{sub 3}/TiAl composites were in situ synthesized by vacuum sintering mechanically alloyed Ti–50 at.% Al powders coated with carbon nanotubes (CNTs). The pre-alloyed Ti–50 at.% Al powder was obtained by ball milling Ti and Al powders. The multi-walled carbon nanotubes as the carbon resource were covered on the surface of the pre-alloyed powders by immersing them into a water solution containing the CNTs. A zwitterionic surfactant was used to enhance the dispersion of the CNTs on the powder surface. The samples were cold pressed and sintered in vacuum at temperatures from 950 to 1250 °C, respectively. The results show that the reaction of forming Ti{sub 2}AlC can be achieved below 950 °C, which is 150 °C lower than in the Ti–Al–TiC system and 250 °C lower than for the Ti–Al–C system due to the addition of CNTs. Additionally, the reinforcement of Al{sub 2}O{sub 3} particles was introduced in situ in Ti{sub 2}AlC/TiAl by the drying process and subsequent sintering of the composite powders. Dense Ti{sub 2}AlC–Al{sub 2}O{sub 3}/TiAl composites were obtained by sintering at 1250 °C and exhibited a homogeneous distribution of Ti{sub 2}AlC, Al{sub 2}O{sub 3} and precipitated Ti{sub 3}Al particles and a resulting high hardness.

  19. 27Al NMR studies of NpPd5Al2

    International Nuclear Information System (INIS)

    Chudo, H.; Sakai, H.; Tokunaga, Y.; Kambe, S.; Aoki, D.; Homma, Y.; Shiokawa, Y.; Haga, Y.; Ikeda, S.; Matsuda, T.D.; Onuki, Y.; Yasuoka, H.

    2009-01-01

    We present 27 Al NMR studies for a single crystal of the Np-based superconductor NpPd 5 Al 2 (T c =4.9K). We have observed a five-line 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 c . The temperature dependence of the 27 Al nuclear spin-lattice relaxation rate shows no coherence peak below T c , indicating that NpPd 5 Al 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 5 Al 2 .

  20. Magnetic tunnel junctions with AlN and AlNxOy barriers

    International Nuclear Information System (INIS)

    Schwickert, M. M.; Childress, J. R.; Fontana, R. E.; Kellock, A. J.; Rice, P. M.; Ho, M. K.; Thompson, T. J.; Gurney, B. A.

    2001-01-01

    Nonoxide tunnel barriers such as AlN are of interest for magnetic tunnel junctions to avoid the oxidation of the magnetic electrodes. We have investigated the fabrication and properties of thin AlN-based barriers for use in low resistance magnetic tunnel junctions. Electronic, magnetic and structural data of tunnel valves of the form Ta (100 Aa)/PtMn (300 Aa)/CoFe 20 (20 Aa - 25 Aa)/barrier/CoFe 20 (10 - 20 Aa)/NiFe 16 (35 - 40 Aa)/Ta (100 Aa) are presented, where the barrier consists of AlN, AlN x O y or AlN/AlO x with total thicknesses between 8 and 15 Aa. The tunnel junctions were sputter deposited and then lithographically patterned down to 2 x 2μm 2 devices. AlN was deposited by reactive sputtering from an Al target with 20% - 35% N 2 in the Ar sputter gas at room temperature, resulting in stoichiometric growth of AlN x (x=0.50±0.05), as determined by RBS. TEM analysis shows that the as-deposited AlN barrier is crystalline. For AlN barriers and AlN followed by natural O 2 oxidation, we obtain tunnel magnetoresistance >10% with specific junction resistance R j down to 60Ωμm 2 . [copyright] 2001 American Institute of Physics

  1. A study of the Al-rich part of the Al-Re alloy system

    International Nuclear Information System (INIS)

    Balanetskyy, S.; Grushko, B.

    2008-01-01

    The Al-rich part of the Al-Re phase diagram was reinvestigated by scanning and transmission electron microscopy, powder X-ray diffraction and differential thermal analysis. The earlier reported Al 12 Re, Al 6 Re, and Al 11 Re 4 phases were confirmed. Close to the Al 4 Re composition a high-temperature h-Al 4 Re and a low-temperature l-Al 4 Re phase were found to be formed at slightly different compositions. Both exhibited compositional ranges. A new phase was revealed close to the Al 3 Re composition. The Al 11 Re 4 phase is formed congruently at 1650 deg. C, Al 3 Re peritectically at 1610 deg. C, h-Al 4 Re peritectically at 1410 deg. C, l-Al 4 Re peritectically at ∼1000 deg. C, Al 6 Re peritectically at 813 deg. C and Al 12 Re peritectically at 746 deg. C. Finally, the Al 12 Re-(Al) eutectic is formed at 658 deg. C. The Al 3 Re and h-Al 4 Re are decomposed by eutectoid reactions at ∼946 and 833 deg., respectively. The structure of the h-Al 4 Re phase has not yet been clarified, but it is distinctly different from the Al 4 W phase suggested earlier. The structure of l-Al 4 Re was confirmed. The Al 3 Re phase was found to have a monoclinic structure with a = 0.5180(4) nm, b = 3.97641(9) nm, c = 0.4955(3) nm and β = 99.55(7) o

  2. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    success. As an Arab participant acknowledged very early on, “the situation was really harsh. All the brothers were tired,” as they lacked food and... glorious battles that occurred during the early Islamic period.133 He stressed the importance of the battlefield as the path to achieve honor and dignity...diaspora in Waziristan. In the words of Walid Othmani, a French jihadi trained by al-Qa`ida in Waziristan in 2008, “[Al-Libi] was someone well-known and

  3. SAP-like ultrafine-grained Al composites dispersion strengthened with nanometric AlN

    International Nuclear Information System (INIS)

    Balog, M.; Krizik, P.; Yan, M.; Simancik, F.; Schaffer, G.B.; Qian, M.

    2013-01-01

    This paper reports the development of novel Sinter-Aluminum-Pulver (SAP)-like Al–AlN nanocomposites via replacing the native Al 2 O 3 thin films on fine Al powder with a large volume fraction of in situ formed nanometric AlN dispersoids. Fine gas-atomized Al powder (d 50 =1.3 µm) compacts were first partially nitrided at 590 °C in flowing nitrogen, controlled by a small addition of Sn (0.3–0.4 wt%), and subsequently consolidated by hot direct extrusion. The resulting Al–AlN composites consisted of submicrometric Al grains reinforced with nanometric AlN dispersoids together with some nanometric Al 2 O 3 dispersoids. An Al–13 vol% AlN nanocomposite fabricated this way achieved exceptional ultimate tensile strength of 227 MPa, yield strength of 195 MPa and Young's modulus of 66 GPa at 300 °C, superior to typical SAP materials and coarse grained Al–AlN composites. In addition, the Al–13 vol% AlN nanocomposite exhibited good thermal stability up to 500 °C. The strengthening mechanism is discussed

  4. Analisis Kecenderungan Manhaj Akidah Shaykh Shams al-Din al-Sumatera’i

    Directory of Open Access Journals (Sweden)

    MOHD HAIDHAR KAMARZAMAN

    2016-12-01

    Full Text Available Shaykh Shams al-Din al-Sumatera'i is a very great and respected scholar during 16th and 17th century of Acheh. His knowledge in various fields recognized by local and international scholars. He had been a Qadi Malik al-’Adil, a religious leader, who became a referred by communities and country during the reign of the three Sultans of Aceh. He has authored nearly 40 pieces of books related to the theology and sufism. This study focuses on the methods used by Shaykh Shams al-Din al-Sumatera'i in his theological writings. This study found that Shaykh Shams al-Din al-Sumatera'i had used six methods in the such writings.

  5. Ultrasonic spot welding of Al/Mg/Al tri-layered clad sheets

    International Nuclear Information System (INIS)

    Macwan, A.; Patel, V.K.; Jiang, X.Q.; Li, C.; Bhole, S.D.; Chen, D.L.

    2014-01-01

    Highlights: • The optimal welding condition is achieved at 100 J and 0.1 s. • Failure load first increases and then decreases with increasing welding energy. • The highest failure load after welding is close to that of the clad sheets. • At low energy levels failure occurs in the mode of interfacial failure. • At high energy levels failure takes place at the edge of nugget region. - Abstract: Solid-state ultrasonic spot welding (USW) was used to join Al/Mg/Al tri-layered clad sheets, aiming at exploring weldability and identifying failure mode in relation to the welding energy. It was observed that the application of a low welding energy of 100 J was able to achieve the optimal welding condition during USW at a very short welding time of 0.1 s for the tri-layered clad sheets. The optimal lap shear failure load obtained was equivalent to that of the as-received Al/Mg/Al tri-layered clad sheets. With increasing welding energy, the lap shear failure load initially increased and then decreased after reaching a maximum value. At a welding energy of 25 J, failure occurred in the mode of interfacial failure along the center Al/Al weld interface due to insufficient bonding. At a welding energy of 50 J, 75 J and 100 J, failure was also characterized by the interfacial failure mode, but it occurred along the Al/Mg clad interface rather than the center Al/Al weld interface, suggesting stronger bonding of the Al/Al weld interface than that of the Al/Mg clad interface. The overall weld strength of the Al/Mg/Al tri-layered clad sheets was thus governed by the Al/Mg clad interface strength. At a welding energy of 125 J and 150 J, thinning of weld nugget and extensive deformation at the edge of welding tip caused failure at the edge of nugget region, leading to a lower lap shear failure load

  6. High-pressure high-temperature experiments: Windows to the Universe; Experimentos a alta presion y alta temperatura: Ventanas al universo

    Energy Technology Data Exchange (ETDEWEB)

    Santaria-Perez, D.

    2011-07-01

    From Earth compositional arguments suggested by indirect methods, such as the propagation of seismic waves, is possible to generate in the laboratory pressure and temperature conditions similar to those of the Earth or other planet interiors and to study how these conditions affect to a certain metal or mineral. These experiments are, therefore, windows to the Universe. The aim of this chapter is to illustrate the huge power of the experimental high-pressure high-temperature techniques and give a global overview of their application to different geophysical fields. Finally, we will introduce the MALTA Consolider Team, which gather most of the Spanish high-pressure community, and present their available high-pressure facilities. (Author) 28 refs.

  7. KITAB AL-SANĪ AL-MAṬĀLIB: INTERKONEKSI NAHWU DAN TASAWUF

    Directory of Open Access Journals (Sweden)

    Zakiyah Zakiyah

    2012-12-01

    Tulisan ini mereview buku yang berjudul al-Sanī al-Maṭālib yang ditulis oleh Kiai Nur Iman Mlangi Yogyakarta. Buku ini ditulis dalam bahasa Arab yang me­ngandung interkoneksi antara ilmu Nahwu (tata bahasa Arab dengan mis­tisis­me. Buku ini sangat menarik karena kenyataan bahwa kedua pengetahuan tersebut memiliki aturan sendiri-sendiri. Selain itu, sangat sedikit penulis yang menulis dengan gaya seperti itu. Salah satunya adalah Syaikh Abdul Qadir bin Ahmad al-Kuhany dengan karyanya yang berjudul Manniyat al-Fāqir al-Munjarid wa Sayrat al-Murīd al-Mutafarrid. Buku al-Saniy al-Muthalib diduga telah ditulis pada akhir abad ke-18 atau awal abad ke-19, menurut periode kehidupan Kiai Nur Iman yaitu sekitar pertengahan abad ke-18. Aturan Nahwu dalam buku ini dijelaskan secara teosofi yang dimulai dengan penjelasan mengenai tauhid (keesaan Tuhan sebagai kajian dasar bagi orang Islam, yang diikuti dengan makna dari masing-masing aturan bahasa Arab dalam aspek mistiknya.

  8. Rekonstruksi Konsep Ijtihad: Studi Pemikiran Ben’umar tentang al-Ijtihad fi al-Waqi’

    Directory of Open Access Journals (Sweden)

    Duski Ibrahim

    2015-10-01

    Full Text Available This paper is the result of a research that evaluating the reconstruction the concept of ijtihad, by discuss the idea of al-Ijtihad Ben'umar fi al-waqi’. This paper concludes that Al-Ijtihad fi al-waqi’ is actually a form of collective ijtihad (al ijtihad al-jama'i, by gathering the experts of shari'ah law (fuqaha` ash-shar'i and experts Researchers and scientists (khubara` al-'ashr. Because experts know the nash purposes, while researchers and scientists (al-khubara` know the reality (al-waqi’, the effects in the future (ma'alat = future effect and challenges (tahaddiyat. The idea of formulating the concept of al-ijtihad fi al-waqi’ emerged based on a premise that ijtihad is a creation of experts to implement Islamic law in society. Therefore, the concept of ijtihad experienced a significant development, start from using the nash from the language aspects, continue to the using of logic. At the moment when the situation people are increasingly develop, then the creation of ijtihad become a necessary to developed, for example in the form of al-ijtihad fi al-waqi’ . About the source of the formation of the concept of al -ijtihad fi al-waqi’ comes from theory about the functions of nash, al-manath theory in Islamic law, and supported by the theory of al-mashlalah al-mursalah.

  9. Colangio-debitomanometría por sonda en T en control posoperatorio

    Directory of Open Access Journals (Sweden)

    Osvaldo Olivera Sandoval

    1995-12-01

    Full Text Available Se realiza un estudio prospectivo en 30 enfermos en los hospitales Clinicoquirúrgico Docente "Miguel Enríquez" y Oued-Rhiou de Argelia durante 1986 a 1990, a quienes se les realizó coledocostomía. Al no disponer de equipos de circuito cerrado de televisión para el estudio dinámico del esfínter de Oddi, se midieron las presiones y el débito biliar al realizárseles la colangiografía de control, lo que permitió conocer no sólo la morfología de las vías biliares, sino también la dinámica del esfínter, alteradas en ocasiones por edema, esclerosis o cálculos pequeños que actúan como válvula. El resultado de esta prueba posibilitó la extracción de cálculos residuales por papilo-esfinterotomía transduodenal endoscópica. Los resultados fueron satisfactorios al lograrse realizar un estudio más completo de la función biliar en su status posoperatorio mediato y poder solucionar complicaciones biliares en 5 pacientes

  10. Study of the 26Al(n,p)26Mg and 26Al(n,α)23Na reactions using the 27Al(p,p')27Al inelastic scattering reaction

    International Nuclear Information System (INIS)

    Benamara, S; De Séréville, N; Hammache, F; Stefan, I; Roussel, P; Ancelin, S; Assié, M; Guillot, J; Le Crom, B; Lefebvre, L; Adsley, P; Laird, A M; Barton, C; Diget, C; Fox, S; Coc, A; Deloncle, I; Hamadache, C; Kiener, J; Lefebfre-Schuhl, A

    2016-01-01

    26 Al was the first cosmic radioactivity ever detected in the galaxy as well as one of the first extinct radioactivity observed in refractory phases of meteorites. Its nucleosynthesis in massive stars is still uncertain mainly due to the lack of nuclear information concerning the 26 Al(n,p) 26 Mg and 26 Al(n,α) 23 Na reactions. We report on a single and coincidence measurement of the 27 Al(p,p') 27 Al(p) 26 Mg and 27 Al(p,p') 27 Al(α) 23 Na reactions performed at the Orsay TANDEM facility aiming at the spectroscopy study of 27 Al above the neutron threshold. Fourteen states are observed for the first time within 350 keV above the 26 Al+n threshold. (paper)

  11. AlN/Al dual protective coatings on NdFeB by DC magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Li Jinlong; Mao Shoudong; Sun Kefei [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Li Xiaomin [Shanghai Institute of Ceramics Chinese Academy of Sciences, Shanghai 200050 (China); Song Zhenlun [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)], E-mail: songzhenlun@nimte.ac.cn

    2009-11-15

    AlN/Al dual protective coatings were prepared on NdFeB by DC magnetron sputtering in a home-made industrial apparatus. Comparing with Al coating, AlN/Al coatings have a denser structure of an outmost AlN amorphous layer following an inner Al columnar crystal layer. The coatings and NdFeB substrate combine well, and moreover, there is occurrence of metallurgy bonding in the interface layer. Both Al and AlN/Al coatings have a good protective ability to NdFeB. Especially, the corrosion resistance of AlN/Al coated NdFeB is improved largely. AlN/Al and Al protective coatings not only do not deteriorate the magnetic properties of NdFeB, but contribute to their slight increase.

  12. AlN/Al dual protective coatings on NdFeB by DC magnetron sputtering

    International Nuclear Information System (INIS)

    Li Jinlong; Mao Shoudong; Sun Kefei; Li Xiaomin; Song Zhenlun

    2009-01-01

    AlN/Al dual protective coatings were prepared on NdFeB by DC magnetron sputtering in a home-made industrial apparatus. Comparing with Al coating, AlN/Al coatings have a denser structure of an outmost AlN amorphous layer following an inner Al columnar crystal layer. The coatings and NdFeB substrate combine well, and moreover, there is occurrence of metallurgy bonding in the interface layer. Both Al and AlN/Al coatings have a good protective ability to NdFeB. Especially, the corrosion resistance of AlN/Al coated NdFeB is improved largely. AlN/Al and Al protective coatings not only do not deteriorate the magnetic properties of NdFeB, but contribute to their slight increase.

  13. 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.

  14. 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.)

  15. SIMULACIÓN DEL PROCESO FERMENTATIVO PARA LA OBTENCIÓN DE BIOETANOL A PARTIR DE RESIDUOS DE ARROZ

    Directory of Open Access Journals (Sweden)

    Verónica Capdevila

    2015-01-01

    Full Text Available En este trabajo se desarrolla un modelo de simulación del proceso fermentación/separación de bioetanol a partir de cascarilla de arroz pretratada e hidrolizada, aplicando el simulador Aspen HYSYS. Estudios de sensibilidad realizados sobre el modelo desarrollado permitieron obtener niveles para las variables seleccionadas de 1:2,89 relación biomasa:agua; 50 t/h caudal de biomasa y 30°C temperatura de entrada al separador, que conducen a maximizar el rendimiento de bioetanol. A partir de estas variables se obtiene una producción de bioetanol de 8,81 t/h con una pureza del 65,51% p/p equivalentes a un caudal de biomasa tratada hidrolizada de 50 t/h. Este trabajo representa un avance del desarrollo del modelado del proceso completo de obtención de bioetanol de segunda generación a partir de residuos de la industria arrocera.

  16. Overview of the Lambda-* Performance Reasoning Frameworks

    Science.gov (United States)

    2009-02-01

    portion of our Web site (http://www.sei.cmu.edu/publications/pubweb.html). i | CMU/SEI-2008-TR-020 Table of Contents Acknowledgments vii Abstract ix...Julio Luis; & Drake, Jose M. “Sim-MAST: Simulador de Sis- temas Distribuidos de Tiempo Real.” XII Jornadas de Concurrencia y Sistemas Distribuidos, 2004

  17. ANÁLISIS DE LA SOLUBILIDAD DE LA MEZCLA GASOLINA-ETANOL-AGUA A DIFERENTES PRESIONES Y TEMPERATURAS

    Directory of Open Access Journals (Sweden)

    Michael Fernando Rondón

    2015-01-01

    Full Text Available En este artículo se presenta el efecto de pruebas de solubilidad hechas a mezclas gasolina-etanol-agua mediante ensayos de tolerancia al agua (temperatura de separación de fase paramuestras de E10, E15, E20, E25 y E30. Adicionalmente, se estudia el efecto de la presión de vacíosobre la separación de la mezcla. Los resultados muestran que las temperaturas de separacióndependen inversamente de la cantidad de etanol en la mezcla combustible y directamente de lacantidad de agua en la misma. Así mismo, se encontró que la influencia de la presión de vacío esmínima cuando la mezcla combustible se encuentra en estado líquido.

  18. KONSEPSI AL-QURAN DAN AL-HADITS TENTANG OPERASIONAL BANK SYARIAH

    Directory of Open Access Journals (Sweden)

    Muhammad Ardy Zaini

    2015-01-01

    Full Text Available Islam hadir dengan beberapa tujuan, diantaranya adalah terciptanya khoirul ummah dan rahmatan lil’alamin dengan al-Qur’an dan al-Hadits sebagai penuntun umat Islam demi tercapainya tujuan tersebut. Sebagai pedoman hidup, al-Qur’an dan al-Hadits memberikan berbagai petunjuk tentang keteraturan dan permasalahan hidup, termasuk didalamnya mengenai perbankan yang telah memenuhi hampir separuh sisi-sisi kehidupan manusia. Untuk memaksimal ajaran syariah secara kaffah, maka nilai-nilai yang terdapat dalam al-Quran harus mampu diturunkan pada tataran praktis. Salah satu usaha dan langkah dalam rangka menemukan formula perbankan masa depan, al-Quran dan Hadits memiliki konsepsi dalam kegiatan operasional Bank Syariah. Hal ini dilakukan untuk membentuk sikap mental atau watak yang terjabarkan dalam pola berpikir, cara berbicara, dan etika bertingkah laku, sebagai ekspresi jiwa dari manusia yang beriman dan bertakwa kepada Allah Swt. Agar umat Islam mampu menjadi umat yang unggul (khayr ummah.

  19. 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.

  20. The formation of AlB2 in an Al-B master alloy

    International Nuclear Information System (INIS)

    Wang Xiaoming

    2005-01-01

    The formation of borides in an Al-3 wt.%B master alloy, produced via chemical reactions of KBF 4 and aluminium has been investigated. The chemical reactions produce boron, which dissolves into molten aluminium and subsequently forms aluminium borides. Backscattered electron imaging (BEI) of the Al-3 wt.%B master alloy under a scanning electron microscope (SEM) revealed the presence of two types of phases that contain different levels of boron. Combined with X-ray diffraction (XRD) results, the two types of phases are identified as AlB 2 on AlB 12 . This gives a direct evidence for a peritectic reaction of AlB 12 and aluminium, which produces AlB 2 . The thermodynamic properties of the reactions that may be involved are examined, and the presence of AlB 12 phase in the master alloy explained. The observed microstructure is explained according to the peritectic reaction in an Al-B phase diagram. The stability of AlB 2 and AlB 12 at lower temperature than 975 deg. C is clarified

  1. Construction and evaluation of multi-component Zn-Al based bearing alloys (Zn-Al-Si, Zn-Al-Cu)

    International Nuclear Information System (INIS)

    Shahmiri, M.; Shahin, K.

    2001-01-01

    Zn-Al based alloys, with excellent mechanical properties, are finding increasing applications in various industries, especially bearing and bushing fields. Observed dimensional instabilities, in their multicomponent systems, (e. g. Zn-Al-Si and, Zn-Al Si-Cu), is believed to be as the result of some kinds of phase transformation, due to the temperature variations, while in service. Profound understanding of the phase transformations due to the temperature variation, requires detailed evaluations of the isothermal sections of the multi-components phase diagrams of Zn-Al-Si and, Zn-Al-Si-Cu alloy systems. In the present article, the isothermal sections of the aforementioned ternary and quaternary systems in the solid state regions have been investigated and observed phase transitions have been critically evaluated

  2. The Existence of a Designer Al=Al Double Bond in the LiAl2 H4- Cluster Formed by Electronic Transmutation.

    Science.gov (United States)

    Lundell, Katie A; Zhang, Xinxing; Boldyrev, Alexander I; Bowen, Kit H

    2017-12-22

    The Al=Al double bond is elusive in chemistry. Herein we report the results obtained via combined photoelectron spectroscopy and ab initio studies of the LiAl 2 H 4 - cluster that confirm the formation of a conventional Al=Al double bond. Comprehensive searches for the most stable structures of the LiAl 2 H 4 - cluster have shown that the global minimum isomer I possesses a geometric structure which resembles that of Si 2 H 4 , demonstrating a successful example of the transmutation of Al atoms into Si atoms by electron donation. Theoretical simulations of the photoelectron spectrum discovered the coexistence of two isomers in the ion beam, including the one with the Al=Al double bond. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Characterization of N-polar AlN in GaN/AlN/(Al,Ga)N heterostructures grown by metal-organic chemical vapor deposition

    Science.gov (United States)

    Li, Haoran; Mazumder, Baishakhi; Bonef, Bastien; Keller, Stacia; Wienecke, Steven; Speck, James S.; Denbaars, Steven P.; Mishra, Umesh K.

    2017-11-01

    In GaN/(Al,Ga)N high-electron-mobility transistors (HEMT), AlN interlayer between GaN channel and AlGaN barrier suppresses alloy scattering and significantly improves the electron mobility of the two-dimensional electron gas. While high concentrations of gallium were previously observed in Al-polar AlN interlayers grown by metal-organic chemical vapor deposition, the N-polar AlN (Al x Ga1-x N) films examined by atom probe tomography in this study exhibited aluminum compositions (x) equal to or higher than 95% over a wide range of growth conditions. The also investigated AlN interlayer in a N-polar GaN/AlN/AlGaN/ S.I. GaN HEMT structure possessed a similarly high x content.

  4. KRITIK ATAS KRITIK EPISTEMOLOGI TAFSIR M. ABIED AL JABIRI: Studi Kritis atas Madkhal ila al Quran al Karim

    Directory of Open Access Journals (Sweden)

    Ahmad Fawaid

    2015-12-01

    Full Text Available This paper critically views the epistemology of Muhammad Abid al Jabiri’s interpretation in his book, Madkhal ila al Quran al Karim. His latest work is projected to make the Quran relevant to mankind today and with certainly critiquing classical Quranic studies that have been constructed by previous scholars. Starting from Arab criticism, which is expected to synergize the gap between Turath and modernity, al Jabiri tried out his theory in the realm of Quranic studies oriented to maintain its originality and interpretation from sectarian influence. Focusing on al Jabiri’s review on the Quran, this paper examines and associates some of the problems with the epistemology of critique in Arab reasoning. Finally, it is inferred that the epistemologic offer of al Jabiri used in Turath is not fully applicable in Quranic studies for several reasons. First, the Quranic studies existed within the chain of sanad in its formation. Secondly, at the application stage, al Jabri often overlooked the sanad and narrations from the companions.

  5. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    International Nuclear Information System (INIS)

    Li, Shuo; Bhushan, Bharat

    2016-01-01

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  6. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuo [School of Materials Science and Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian Distract, Beijing 100083 (China); Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States); Bhushan, Bharat, E-mail: bhushan.2@osu.edu [Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States)

    2016-08-15

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  7. 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.

  8. Optical phonon scattering on electronic mobility in Al2O3/AlGaN/AlN/GaN heterostructures

    Science.gov (United States)

    Zhou, X. J.; Qu, Y.; Ban, S. L.; Wang, Z. P.

    2017-12-01

    Considering the built-in electric fields and the two-mode property of transverse optical phonons in AlGaN material, the electronic eigen-energies and wave functions are obtained by solving Schrödinger equation with the finite difference method. The dispersion relations and potentials of the optical phonons are given by the transfer matrix method. The mobility of the two dimensional electron gas influenced by the optical phonons in Al2O3/AlGaN/AlN/GaN heterostructures is investigated based on the theory of Lei-Ting force balance equation. It is found that the scattering from the half-space phonons is the main factor affecting the electronic mobility, and the influence of the other phonons can be ignored. The results show that the mobility decreases with increasing the thicknesses of Al2O3 and AlN layers, but there is no definite relationship between the mobility and the thickness of AlGaN barrier. The mobility is obviously reduced by increasing Al component in AlGaN crystal to show that the effect of ternary mixed crystals is important. It is also found that the mobility increases first and then decreases as the increment of the fixed charges, but decreases always with increasing temperature. The heterostructures constructed here can be good candidates as metal-oxide-semiconductor high-electron-mobility-transistors since they have higher electronic mobility due to the influence from interface phonons weakened by the AlN interlayer.

  9. Al2O3 adherence on CoCrAl alloys

    International Nuclear Information System (INIS)

    Kingsley, L.M.

    1980-04-01

    Adherence of protective oxides on NiCrAl and CoCrAl superalloys has been promoted by a dispersion of a highly oxygen reactive element or its oxide being produced within the protection system. Two aspects of this subject are investigated here: the use of Al 2 O 3 as both the dispersion and protective oxide; and the production of an HfO 2 dispersion while simultaneously aluminizing the alloy. It was found that an Al 2 O 3 dispersion will act to promote the adherence of an external scale of Al 2 O 3 to a degree comparable to previously tested dispersions and an HfO 2 dispersion comparable to that produced by a Rhines pack treatment is produced during aluminization

  10. 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.' ' '

  11. All About ALS

    Science.gov (United States)

    ... Subscribe August 2015 Print this issue All About ALS Understanding a Devastating Disorder En español Send us ... Sports Concussions Wise Choices How Can I Help ALS Research? If you have ALS, join the National ...

  12. Atomistic simulations of diffusion mechanisms in off-stoichiometric Al-rich Ni3Al

    International Nuclear Information System (INIS)

    Duan, Jinsong

    2007-01-01

    This paper presents dynamics simulation results of diffusion in off-stoichiometric Al-rich Ni 3 Al (Ni 73 Al 27 ) at temperature ranging from 1300 to 1550 K. The interatomic forces are described by the Finnis-Sinclair type N-body potentials. Particular attention is devoted to the effect of the extra 2% of Al atoms sitting on the Ni sublattice as antisite point defects (Al Ni ) on diffusion. Simulation results show that Ni atoms mainly diffuse through the Ni sublattice at the temperatures investigated. Al atoms diffuse via both the intrasublattice and antistructure bridge (ASB) mechanisms. The contribution to Al diffusion from the ASB mechanism decreases at the lower temperature (T Ni ) enhances both Al and Ni diffusion in Ni 73 Al 27 . The Ni-Al coupled diffusion effect is observed and understood at the atomic level for the first time

  13. Methodology and Characteristics of Zad al-masir fi ‘ilm al-tafsirby AllamaIbn al-Jawzī (Urdu

    Directory of Open Access Journals (Sweden)

    Dr. Muhammad Riaz al Azhari

    2017-01-01

    Full Text Available This article describes the methodology and characteristics of Zad al-masir fi ‘ilm al-tafsir. This is one the finest work of AllamaIbn al-Jawzī, a 6th century prominent Interpreter. Several editions of this Tafsir have been published. However, the edition of dar al-kitab al-‘arbi, Beirut published in four volumes is selected for this study. This exegesis is based on conventional narrations, authentic quotations from the Islamic Scholars and lingual & grammatical discussions. As a witness, causes of verses (asbabal-Nuz┴l,Makki and MadaniSurah’s (chapters, the abrogating and abrogated verses (al-nasikhwal-mans┴kh and Islamic jurisprudence have been discussed in it where needed. The quality of this translation which is admirable is that mostly authentic Ahadith from original sources, and references to well known basic books in relevant discussions have been described. `

  14. Phenotypic and genotypic studies of ALS cases in ALS-SMA families.

    Science.gov (United States)

    Corcia, Philippe; Vourc'h, Patrick; Blasco, Helene; Couratier, Philippe; Dangoumau, Audrey; Bellance, Remi; Desnuelle, Claude; Viader, Fausto; Pautot, Vivien; Millecamps, Stephanie; Bakkouche, Salah; Salachas, FranÇois; Andres, Christian R; Meininger, Vincent; Camu, William

    2018-03-01

    Amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) are the most frequent motor neuron disorders in adulthood and infancy, respectively. There is a growing literature supporting common pathophysiological patterns between those disorders. One important clinical issue for that is the co-occurrence of both diseases within a family. To collect families in which ALS and SMA patients co-exist and describe the phenotype and the genotype of ALS patients. Nine families with co-occurrence of SMA and ALS have been gathered over the last 15 years. Epidemiological, phenotype and genetic status were collected. Out of the nine families, six corresponded to the criteria of familial ALS (FALS). Clinical data were available for 11 patients out of the 15 ALS cases. Mean age of onset was 58.5 years, site of onset was lower limbs in nine cases (81.8%), median duration was 22 months. Four ALS patients carried a mutation: three mutations in SOD1 gene (G147N in two cases and one with E121G) and one repeat expansion in the C9ORF72 gene. Three patients had abnormal SMN1 copy numbers. While the high proportion of familial history of ALS cases in these ALS-SMA pedigrees could have suggested that these familial clusters of the two most frequent MND rely on a genetic background, we failed to exclude that this occurred by chance.

  15. Eutectic microstructures of Al-ThA13 and Al-UA14 alloys

    International Nuclear Information System (INIS)

    Vieira, R.R.; Ambrozio Filho, F.

    1990-01-01

    This paper deals on the microstructures of systems Al-ThAl3 and Al-UAL4, which are composed by a non faceted phase (aluminium) and an intermetallic phase (ThAl3 or UAL4) which is normally faceted phase. (C.M.)

  16. Interface reactions in the Al-Si-SiC and Mg-Al-Al{sub 2}O{sub 3} composite systems

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.K. [Commission of the European Communities, Petten (Netherlands). Inst. for Advanced Materials; Fazal-Ur-Rehman [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; Fox, S. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; Flower, H.M. [Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials; West, D.R.F.

    1995-12-31

    Structural and compositional observations are reported on the influence of the interfaces on the mechanisms and kinetics of liquid metal-ceramic reactions in Al-SiC, Al-Si-SiC, Mg-Al{sub 2}O{sub 3} and Mg-Al-Al{sub 2}O{sub 3} composites. The aluminium based materials contained up to 20 vol% SiC in particulate form, and were produced by a spray casting process; subsequently the interface reactions were studied in samples heated to temperatures up to 1100 C. The reaction product was Al{sub 4}C{sub 3} in both Al-SiC and Al-Si-SiC composites. The influence of the crystallography and topology of the SiC particle surfaces on the nucleation of the Al{sub 4}C{sub 3} has been demonstrated; surface asperities play an important role. Growth of nuclei proceeds to form continuous reaction product layers which control the subsequent kinetics. The magnesium based composites contained 5 vol% Al{sub 2}O{sub 3} fibres (3 {mu}m in diameter), and were produced by a liquid infiltration process. SD Safimax fibres with relatively low and high porosity, and also RF Saffil fibres, with a silica binder, were investigated. Fibre porosity plays a major role in accelerating the penetration of Mg into the fibres with reaction to form MgO. Silica binder on the fibre surface transforms to MgO. The reaction rate was reduced by the presence of aluminium in the matrix. The factors controlling the reactions in the aluminium and magnesium based composites are compared. (orig.)

  17. KONSTRUKSI FIQH BUKHARI DALAM KITAB AL-JAMI’ AL-SHAHIH

    Directory of Open Access Journals (Sweden)

    Abdul Sattar

    2011-06-01

    Popularitas Imam Bukhari sebagai penyusun kitab Hadits memiliki posisi yang tinggi di kalangan masyarakat muslim. Kitab Al-Jami ‘al-Shahih karya Imam  Bukhari dianggap sebagai koleksi hadits terbaik setelah Quran. Namun, tidak ada banyak informasi tentang kemampuannya di bidang Hukum Islam (fiqh. Ada beberapa pertanyaan yang dapat diajukan dalam hal tersebut;  pertama, apakah pemikiran Imam Bukhari dipengaruh salah satu dari empat fuqaha Sunni saat menulis al-Jami ‘al-Shahih?. Kedua, apa yang diupayakan Imam Bukhari untuk mengartikulasikan pemikirannya tentang hukum Islam? Dengan menggunakan pendekatan eksploratif, verifikatif dan hermenetical, artikel ini akan mengungkapkan bahwa Imam Bukhari tidak berada di bawah pengaruh madhab tertentu dalam mengartikulasikan pemikirannya tentang hukum Islam. Dia mengartikulasikan pandangannya dengan cara yang unik dan execelent berdasarkan kapasitasnya sebagai muhaddits.

  18. La "historia de los omeyas de al-Andalus" en los Masalik al-Absar

    OpenAIRE

    Molina, Luis

    2005-01-01

    [ES]Los Masalik al-absar de Ibn Fadl Allah al-`Umari incluyen un breve resumen de la Historia de los omeyas de al-Andalus. En este trabajo se analizan las relaciones textuales entre ese pasaje y el Muqtabis de Ibn Hayyan, crónica que resulta ser la fuente casi única utilizada por al-`Umari para redactar ese capítulo. [EN]The Masalik al-absar by Ibn Fadl Allah al-`Umari contains a brief summary of the Umayyad history in al-Andalus. In this article, the textual relationship between this p...

  19. 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

  20. From Kitāb al-ḥadā’iq to Kitāb al-dawā’ir: Reconsidering Ibn al-Sīd al-Batalyawsī’s Philosophical Treatise

    Directory of Open Access Journals (Sweden)

    Eliyahu, Ayala

    2015-06-01

    Full Text Available The philosophical treatise known as Kitāb al-ḥadā’iq is generally ascribed to the 12th century Andalusian author Ibn al-Sīd al-Batalyawsī, although this attribution is sometimes contested. This paper offers a new interpretation of the title, textual history, authorship, sources, and literary genre of this treatise, on the basis of new textual evidence, a reexamination of known evidence, and a comparison between the treatise and Batalyawsī’s works. The conclusions of this study are first, that Kitāb al-ḥadā’iq was not the treatise’s original title, and therefore it should be renamed Kitāb al-dawā’ir; second, that Kitāb al-dawā’ir was originally part of (one of the versions of Batalyawsī’s Kitāb al-masā’il; and third, that the textual and stylistic similarities between this treatise and Batalyawsī’s other works prove the authenticity of the treatise’s attribution to Batalyawsī. In addition, new findings regarding Batalyawsī’s use of formulas from the Rasā’il Ikhwān al-Safā, in Kitāb al-dawā’ir and Kitāb al-masā’il provide further evidence for the deep impact of the Ikhwān on Batalyawsī’s thought, as well as for the close connection between Kitāb al-dawā’ir and Kitāb al-masā’il. This connection is further highlighted according to the attribution of both treatises to the genre of questions and answers in Arabic literature. The evidence gathered in this paper supports the claim that Batalyawsī’s Kitāb al-dawā’ir should be seen as an integral part of his literary oeuvre, as well as of Andalusian philosophical literature in general.Generalmente el tratado filosófico conocido como Kitāb al-ḥadā’iq se asocia al autor andalusí del siglo XII Ibn al-Sid al-Batalyawsī, aunque esta atribución ha sido discutida en ocasiones. Este artículo ofrece una nueva interpretación del título, la historia del texto, la autoría, las fuentes e incluso del género literario al que se

  1. Theory and X-ray Absorption Spectroscopy for Aluminum Coordination Complexes – Al K-Edge Studies of Charge and Bonding in (BDI)Al, (BDI)AlR2, and (BDI)AlX2 Complexes.

    Science.gov (United States)

    Altman, Alison B; Pemmaraju, C D; Camp, Clément; Arnold, John; Minasian, Stefan G; Prendergast, David; Shuh, David K; Tyliszczak, Tolek

    2015-08-19

    Polarized aluminum K-edge X-ray absorption near edge structure (XANES) spectroscopy and first-principles calculations were used to probe electronic structure in a series of (BDI)Al, (BDI)AlX2, and (BDI)AlR2 coordination compounds (X = F, Cl, I; R = H, Me; BDI = 2,6-diisopropylphenyl-β-diketiminate). Spectral interpretations were guided by examination of the calculated transition energies and polarization-dependent oscillator strengths, which agreed well with the XANES spectroscopy measurements. Pre-edge features were assigned to transitions associated with the Al 3p orbitals involved in metal-ligand bonding. Qualitative trends in Al 1s core energy and valence orbital occupation were established through a systematic comparison of excited states derived from Al 3p orbitals with similar symmetries in a molecular orbital framework. These trends suggested that the higher transition energies observed for (BDI)AlX2 systems with more electronegative X(1-) ligands could be ascribed to a decrease in electron density around the aluminum atom, which causes an increase in the attractive potential of the Al nucleus and concomitant increase in the binding energy of the Al 1s core orbitals. For (BDI)Al and (BDI)AlH2 the experimental Al K-edge XANES spectra and spectra calculated using the eXcited electron and Core-Hole (XCH) approach had nearly identical energies for transitions to final state orbitals of similar composition and symmetry. These results implied that the charge distributions about the aluminum atoms in (BDI)Al and (BDI)AlH2 are similar relative to the (BDI)AlX2 and (BDI)AlMe2 compounds, despite having different formal oxidation states of +1 and +3, respectively. However, (BDI)Al was unique in that it exhibited a low-energy feature that was attributed to transitions into a low-lying p-orbital of b1 symmetry that is localized on Al and orthogonal to the (BDI)Al plane. The presence of this low-energy unoccupied molecular orbital on electron-rich (BDI)Al distinguishes

  2. Análisis de la distribución de presiones estáticas en silos cilíndricos con tolva excéntrica mediante el M. E. F. Influencia de la excentricidad y comparación con el Eurocódigo 1

    Directory of Open Access Journals (Sweden)

    Vidal López, Pablo

    2001-04-01

    Full Text Available At the European level, silos are considered under the European Standards (Eurocode 1, Part 4. Actions in si/os and tanks, with no proposed method of calculation in the case of an eccentric outlet. The guidelines include a brief mention that eccentricity should not exceed 25% of the silo diameter and that in the future, attempts will be made to cover large eccentricities. We have developed an analysis of static pressure distributions in grain silos with eccentric outlets. To this end, silos were modelled using ANSYS 5.5. According to the F.E.M. maximum normal pressures on the silo wall correspond to the si/o-hopper junction. on the opposite side to the displacement of the outlet for any eccentricity, increasing at this point as hopper eccentricity rises. Compared to the Eurocode, static pressures are proposed when the hopper is centered and considered to be valid up to an eccentricity limit of 0.25 times the diameter , their redistribution at the hopper wall when this is eccentric may be observed by means of the FE.M. increasing on the opposite side to the outlet and decreasing on the same side with respect to the central hopper. This leads us to conclude that a more conservative method of calculation should be used in the Eurocode for normal pressures on the hopper wall when centered, and coefficients drawn up to include the variations produced in the static state when it is off-center.En Europa las acciones en silos se recogen en la Norma Europea (ENV 1991-4. Eurocode l. Part 4: Actions on silos and tanks., sin proponer método alguno de cálculo cuando la boca de salida es excéntrica, limitándose a mencionar que la excentricidad de ésta no debe de ser mayor del 25% del diámetro y mencionando que en un futuro se intentará que cubra las grandes excentricidades. En este artículo realizamos un análisis de la distribución de presiones estáticas en silos cilíndricos con tolva excéntrica. Para ello hemos usado el programa ANSYS 5.5. con

  3. Thermodynamic properties of Al-Mn, Al-Cu, and Al-Fe-Cu melts and their relations to liquid and quasicrystal structure

    International Nuclear Information System (INIS)

    Zaitsev, A I; Zaitseva, N E; Shimko, R Yu; Arutyunyan, N A; Dunaev, S F; Kraposhin, V S; Lam, Ha Thanh

    2008-01-01

    Thermodynamic properties of molten Al-Mn, Al-Cu and Al-Fe-Cu alloys in a wide temperature range of 1123-1878 K and the whole range of concentrations have been studied using the integral effusion method and Knudsen mass spectrometry. Thermodynamic functions of melts were described by the associated solution model. The possibility of icosahedral quasicrystal (i-QC) precipitation from liquid Al-Mn and Al-Cu-Fe alloys was found to be a consequence of the existence in liquid associates (clusters). A geometric model is suggested for the structure of associates in liquid

  4. Ecotest mamario: una nueva herramienta para la elección del plano de ubicación de los implantes

    Directory of Open Access Journals (Sweden)

    Guillermo Siemienczuk

    2016-03-01

    Full Text Available Antecedentes y Objetivos. Para obtener los mejores resultados en mastoplastia de aumento con implantes, independientemente del volumen y la forma de los mismos, es necesaria la correcta elección del bolsillo de colocación. Para definir el plano apropiado, hasta ahora, nosotros usábamos el clásico test del pellizco (pinch test siguiendo la corriente bibliográfica mundial. Material y Método. El hecho de que esta medición puede resultar subjetiva y variable debido a las diferentes presiones ejercidas al ser realizado por distintos cirujanos, sumado a que no permite ver lo que realmente estamos pinzando, nos ha llevado a desarrollar la idea de medirlo fiel y objetivamente por medio de un estudio ecográfico preoperatorio al que denominamos ecotest del polo superior. Resultados. Con ésta nueva herramienta diagnóstica hemos evaluado a 95 pacientes, con un seguimiento mínimo de 6 meses de postoperatorio. Conclusiones. De este modo comprobamos la mejoría en nuestros resultados estéticos.

  5. 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.

  6. Tetragonal phase in Al-rich region of U-Fe-Al system

    International Nuclear Information System (INIS)

    Meshi, L.; Zenou, V.; Ezersky, V.; Munitz, A.; Talianker, M.

    2005-01-01

    A new ternary aluminide U 2 FeAl 20 with the approximate composition Al-4.2at% Fe-8.5at% U was observed in the Al-rich corner of the U-Al-Fe system. Transmission electron microscopy and electron microdiffraction technique were used for characterization of the structure of this phase. It has a tetragonal unit cell with the parameters a=12.4A and c=10.3A and can be described by the space group I4-bar 2m

  7. Ilhaq al-Masa'il bi Nazairiha dan Penerapannya dalam Bahth al-Masa'il

    Directory of Open Access Journals (Sweden)

    Luthfi Hadi Aminuddin

    2013-11-01

    Full Text Available Abstract: Ilh}a>q al-Masa>’il bi Naz}a>iriha is one of the methods used by Nahdlatul Ulama in resisting the opinion based on (manhaji analytical concept of Islamic jurisprudence (the solution for complex social problems as the main purpose of Islamic shari’ah. As known that, up to now, ilh}a>q has been understood as a process of answering a new case by the way of equating to the old one which is written in the book called al-mu’tabarah. Such ilh}a>q has got many criticisms both from the definitions, procedures and its epistemogical footing. This paper is about to reveal how the NU clerics of Islam understand the concept of Ilh}a>q}, what its epistemological footing was and how the concept was applied in discussing many cases (bah}th al-masa>’il. Based on the writer’s study to several documents of decision results of NU that Ilh}a>q did not only simplify to equate the new cases with the old ones that have been freely discussed in the books of al-mu’tabarah, but both cases should have similar legal substance, that is, both should be under the decrees of laws of al-qawa> ‘id al-fiqhi>yah. Thus, Ilh}a>q is actually answering the problem by applying al-qawa>‘id al-fiqhi>yah, whereas the formulation al-qawa>‘id al-fiqhi>yah itself was set off from the examination of a number of furu>’ generated by qiya> s. This paper also found three variations of the implementation of Ilh}a>q in bah}th al-masa>’il. First, the application of Ilh}a>q was without mentioning al-qawa> ‘id al-fiqhi>yah which covered new cases (mulh}aq and the old case law that has been known in the books of fiqh (mulh}aq bih/attached to. Second, the application of Ilh}a>q was accompanied by mentioning mulh}aq bih and al-qawa> ‘id al-fiqhi>yah. Third, the application of Ilh}a>q, was only by the mentioning al-qawa> ‘id al-fiqhi>yah.

  8. Pressure gradient of a two-region solid-liquid flow in horizontal wells; Gradiente de presion de un flujo bifasico solido-liquido de dos regiones en pozos horizontales

    Energy Technology Data Exchange (ETDEWEB)

    Salazar Mendoza, R.; Garcia Gutierrez, A. [Centro Nacional de Investigacion y Desarrollo Tecnologico (CENIDET), Cuernavaca, Morelos (Mexico); Espinosa Paredes, G. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico)

    2005-12-01

    A theoretical analysis is presented for the problem of cutting transport in a two-region, slurry-flow system in horizontal pipes, with a stationary bed of drill cuttings as a porous medium (w-region) below a two-phase dispersed flow (n-region). Volume averaging was applied to derive a rigorous mathematical model where each variable is precisely defined. The model includes volume-averaged transport equations for both the two-phase dispersed flow and the porous-medium regions, and terms from a macroscopic forces balance. The solution of the two-region model allowed evaluation of the behavior of the pressure gradient as a function of velocity, total volume fraction of cuttings, and the relationship between the height of the stationary bed and pipe diameter. It is based on a backward, finite-difference explicit scheme. The simulated physical system is a pipe diameter. It is based on a backward, finite-difference explicit scheme. The simulated physical system is a pipe of 4.135 m in horizontal length and 0.0508 m in diameter. A one dimensional, mesh-centered grid is used, consisting of 10 nodes. The numerical results were compared with experimental data on slurry flows and a good agreement was found. [Spanish] Se presenta un analisis teorico del problema de transporte de recortes de perforacion en pozos horizontales. Se estudia el flujo bifasico solido-liquido en dos regiones donde la region inferior es un lecho estacionario de recortes, considerado como medio poroso, mientras que la region superior es un flujo bifasico disperso solido-liquido. Se aplica el metodo de promediado en volumen para derivar de manera matematicamente rigurosa el modelo de dos regiones. El modelo incluye las ecuaciones de transporte promediadas en volumen para cada region y terminos que resultan de un balance de fuerzas macroscopico. La solucion del modelo permite evaluar el comportamiento del gradiente de presion como funcion de la velocidad, la fraccion de volumen de recortes total y la

  9. Nanoindentation studies of ex situ AlN/Al metal matrix nanocomposites

    International Nuclear Information System (INIS)

    Fale, Sandeep; Likhite, Ajay; Bhatt, Jatin

    2014-01-01

    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

  10. Simulación de la precipitación de inclusiones en diferentes etapas del procesamiento del acero líquido

    Directory of Open Access Journals (Sweden)

    Carreño, V.

    1998-05-01

    Full Text Available Steelmaking processes are continuously improved in order to attend the increasing requirements of the cleanness of the liquid metal. At the refining stages, as deoxidation and desulphuration, the formation of inclusions of oxides and sulphides is promoted, which on the other hand, are the most frequent inclusions. In this work a mathematical simulator of the precipitation and chemical composition of non-metallic inclusions at different steps of the steelmaking process is presented. To this purpose, it is assumed that inclusions formed by reoxidation can be simulated by increasing arbitrarily the oxygen levels consumed by the residual elements (aluminium, calcium, etc. and starting the chemical reaction with less powerful deoxidants (silicium and manganese. Accordingly, different operative conditions can be simulated. Numerical predictions are compared with experimental results of industrial trials, as well as results included in the bibliography.

    Los procesos de fabricación de acero se mejoran constantemente en respuesta a las demandas del consumidor que exige un mayor control de limpieza del metal líquido en las diversas etapas de su elaboración. En las etapas de refinación, como son desoxidación y desulfuración, se promueve la formación de inclusiones de óxidos y sulfuros, que por otra parte son las más frecuentes en el acero líquido. En este trabajo se presenta un simulador matemático que predice la precipitación y composición de las inclusiones no metálicas que se encuentran en el acero líquido en diferentes etapas de su procesamiento, asumiendo que las inclusiones formadas por reoxidación también se pueden simular al incrementar arbitrariamente los niveles de oxígeno que deberán consumir los elementos residuales altamente oxidables (Al, Ca, y empezar la reacción con los desoxidantes menores (Si y Mn. De esta manera se simulan diferentes condiciones de operación. Las predicciones numéricas se comparan con los

  11. Isothermal cross-sections of Sr-Al-Ge and Ba-Al-Ge systems at 673 K

    International Nuclear Information System (INIS)

    Kutsenok, N.L.; Yanson, T.I.

    1987-01-01

    X-ray and microstructural analyses are used to study phase equilibria in Sr-Al-Ge and Ba-Al-Ge systems. Existence of SrAl 2 Ge 2 , Sr(Al, Ge) 2 Ba(Al, Ge) 2 , Sr 3 Al 2 Ge 2 , Ba 3 Al 2 Ge 2 ternary compounds is confirmed, a new BaGe 4 binary compound and also new ternary compounds of approximate composition Sr 57 Al 30 Ge 13 and Ba 20 Al 40 Ge 40 , which crystal structure is unknown, are detected. Aluminium solubility in SrAl 4 and BaAl 4 binary compounds (0.05 atomic fraction) is determined. Ba(Al, Ge) 2 compound homogeneity region is defined more exactly (aluminium content varies from 0.27 to 0.51 at. fractions)

  12. Production of 26Al by spallation of Fe, Si, Al nuclei

    International Nuclear Information System (INIS)

    Paillard, P.

    1977-01-01

    Cross sections for 7 Be, 10 Be and 26 Al formation in Al, Si and Fe targets bombarded with 0.6 and 24GeV protons have been measured by using highly selective chemical separation and low level background counters. Results for 26 Al at 0.6GeV are in mb: 17.9 + or - 2.7 in Al, 12.5 + or - 2.5 in Si and 0.45 + or - 0.14 in Fe; at 24GeV 2.6 + or - 0.5mb in Fe. Results for 10 Be are not valid on account of experimental difficulties. It is deduced from these values of aluminium in cosmic ray propagation that 26 Al is not yet cosmic ray chronometer [fr

  13. 143 - 148_Makeri et al.

    African Journals Online (AJOL)

    USER

    2015-06-01

    Jun 1, 2015 ... Yuan et al., 2003), antimicrobial activity (Sundarrao et al., 1993; Betancur-Galvis et al., 1999; Takashi et al., 2006), anti-parasitic, anti-malarial activities (Alali et al., 1998; Jaramillo et al., 2000; Luna et al.,. 2005). This study evaluates the antibacterial activity of extract of stem –bark and leaf extracts of Annona.

  14. Phase relationships in the Al-rich region of the Al-Cu-Er system

    International Nuclear Information System (INIS)

    Zhang Ligang; Masset, Patrick J.; Cao Fuyong; Meng Fangui; Liu Libin; Jin Zhanpeng

    2011-01-01

    Research highlights: → One ternary phase τ 1 -Al 8 Cu 4 Er in Al-rich region with a composition of 59.4-60.4 at.% Al, 32.2-33.8 at.% Cu, and 6.4-7.7 at.% Er is observed in both as-cast and annealed alloys. At 673 K, the binary Al 3 Er phase dissolves about 3.51 at.% Cu. → The calculated solidification paths (based on the CALPHAD method) of as-cast alloys are in agreement with the experimental results. → It can be found that the resultant thermodynamic database can be applied to case studies of as-cast alloys, showing that the literature thermodynamic description of the Al-Cu-Er system is reliable as a working basis for computer-assisted alloy design. - Abstract: The Al-rich region of the ternary Al-Cu-Er system is investigated using the method of X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy. Phase equilibria in the Al-rich region of the Al-Cu-Er system at 673 K have been obtained, and the microstructures of as-cast alloys in the Al-rich region are also investigated. One ternary phase τ 1 -Al 8 Cu 4 Er with a composition of 59.4-60.4 at.% Al, 32.2-33.8 at.% Cu, and 6.4-7.7 at.% Er is observed in both as-cast and annealed alloys. At 673 K, the binary Al 3 Er phase dissolves about 3.51 at.% Cu. The calculated solidification paths (based on the CALPHAD method) of as-cast alloys are in agreement with the experimental results.

  15. Mechanical properties and deformation behavior of Al/Al7075, two-phase material

    International Nuclear Information System (INIS)

    Sherafat, Z.; Paydar, M.H.; Ebrahimi, R.; Sohrabi, S.

    2010-01-01

    In the present study, mechanical properties and deformation behavior of Al/Al7075, two-phase material were investigated. The two-phase materials were fabricated by mixing commercially pure Al powder with Al7075 chips and consolidating the mixture through hot extrusion process at 500 o C. Mechanical properties and deformation behavior of the fabricated samples were evaluated using tensile and compression tests. A scanning electron microscope was used to study the fracture surface of the samples including different amount of Al powder, after they were fractured in tensile test. The results of the tensile and compression tests showed that with decreasing the amount of Al powder, the strength increases and ductility decreases. Calculation of work hardening exponent (n) indicated that deformation behavior does not follow a regular trend. In a way that the n value was approved to be variable and a strong function of strain and Al powder wt% of the sample. The results of the fractography studies indicate that the type of fracture happened changes from completely ductile to nearly brittle by decreasing the wt% of Al powder from 90% to 40%.

  16. A Scholar from Saray: Mawlana Zada al-Sarayi (754/1353–791/1389 in the Biographical Dictionary of Taqi al-Din al-Maqrizi (766/1365–845/1441 “Kitab al-Muqaffa al-Kabir” (The Great Rhymed Book

    Directory of Open Access Journals (Sweden)

    D.R. Zaynuddinov

    2017-03-01

    Full Text Available Research objective: to introduce into academic circulation previously unknown source on the Golden Horde history. Research materials: biographical dictionary of Taqi al-Din al-Maqrizi (766/1365 – 845/1441 “Kitab al-Muqaffa al-Kabir” (The Great Rhymed Book. Results and novelty of the research: This article contains materials from the works of historians engaged in the narrative biography, which V.G. Tiesenhausen did not include in his “Collection of Materials on the Golden Horde history (extract from Arab writings”, although their writings contain very valuable information about the Golden Horde History. Research novelty consists in the fact that the author of this article presents one paragraph from biographical dictionary of Taqi al-Din al-Maqrizi, whose article number 421 provides information about a scholar from Saray – Mawlana Zada al-Sarayi. The author provides its translation and commentary referring to the more than ten medieval Arab sources. After receiving basic education at home, Mawlana Zada al-Sarayi traveled to many Eastern countries in search of knowledge and after having received high recognition he settled in Cairo as a teacher of Sharia Sciences. Despite the fact that his life was interrupted at an early age (36 years, he left a deep mark in science. His son Muhibbu al-Din (Cairo, 791/1389 – Mecca, Friday, the 3rd of Dhu al-Hijjah 859/13 November 1455 also became a great scholar as well as an imam of Sultan al-Ashraf Barsbay himself and other sultans after him. Nisba al-Sarayi sounded on the lips of the Ulema of the East as a symbol of learnedness and high temper. As a result of research it must be said that the study of life of Mawlana Zada al-Sarayi (754/1353 – 791/1389 and the number of migrants from Desht-i Kipchak in Egypt will help researchers in a deeper and more detailed study of the Golden Horde history.

  17. Improved AlGaN/GaN HEMTs Grown on Si Substrates Using Stacked AlGaN/AlN Interlayer by MOCVD

    International Nuclear Information System (INIS)

    Wang Yong; Yu Nai-Sen; Li Ming; Lau Kei-May

    2011-01-01

    AlGaN/GaN high electron mobility transistors (HEMTs) are grown on 2-inch Si (111) substrates by MOCVD. The stacked AlGaN/AlN interlayer with different AlGaN thickness and indium surfactant doped is designed and optimized to relieve the tensile stress during GaN epitaxial growth. The top 1.0μm GaN buffer layer grown on the optimized AlGaN/AlN interlayer shows a crack-free and shining surface. The XRD results show that GaN(002) FWHM is 480 arcsec and GaN(102) FWHM is 900 arcsec. The AGaN/GaN HEMTs with optimized and non-optimized AlGaN/AlN interlayer are grown and processed for comparison and the dc and rf characteristics are characterized. For the dc characteristics of the device with optimized AlGaN/AlN interlayer, maximum drain current density I dss of 737mA/mm, peak transconductance G m of 185mS/mm, drain leakage current density I ds of 1.7μA/mm, gate leakage current density I gs of 24.8 μA/mm and off-state breakdown voltage V BR of 67 V are achieved with L g /W g /L gs /L gd = 1/10/1/1 μm. For the small signal rf characteristics of the device with optimized AlGaN/AlN interlayer, current gain cutoff frequency f T of 8.3 GHz and power gain cutoff frequency f max of 19.9 GHz are achieved with L g /W g /L gs /L gd = 1/100/1/1 μm. Furthermore, the best rf performance with f T of 14.5 GHz and f max of 37.3 GHz is achieved with a reduced gate length of 0.7μm. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  18. Simulador de un optimizador físico de consultas relacionales basado en costes que considere predicados complejos

    OpenAIRE

    Fernández Rodríguez, Sergio

    2012-01-01

    Una de las fases del proceso de tratamiento de una consulta que lleva a cabo el tipo de lenguaje utilizado por los SGBD (lenguajes declarativos) y, más concretamente en la fase de optimización, es la que da sentido al software sobre el cual se trabajará a lo largo de este proyecto. Hay tres tipos de optimización (semántica, sintáctica, física); dicho programa simula sólo uno de los tres tipos de optimizaciones que se realizan: la optimización física.

  19. 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.

  20. Predicting glass-forming compositions in the Al-La and Al-La-Ni systems

    International Nuclear Information System (INIS)

    Gargarella, P.; de Oliveira, M.F.; Kiminami, C.S.; Pauly, S.; Kuehn, U.; Bolfarini, C.; Botta, W.J.; Eckert, J.

    2011-01-01

    Research highlights: → The glass-forming ability of the Al-La and Al-La-Ni systems was studied using the λ* and the λ.Δe criteria. → Both criteria predicted with just 1% at. of error the best glass-former verified so far in the Al-La system. → Four new glass-former compositions could be predicted in the Al-La-Ni system using the λ.Δe criterion. → The best glass-former reported so far in the Al-La-Ni system was found. - Abstract: In this work, a criterion considering the topological instability (λ) and the differences in the electronegativity of the constituent elements (Δe) was applied to the Al-La and Al-Ni-La systems in order to predict the best glass-forming compositions. The results were compared with literature data and with our own experimental data for the Al-La-Ni system. The alloy described in the literature as the best glass former in the Al-La system is located near the point with local maximum for the λ.Δe criterion. A good agreement was found between the predictions of the λ.Δe criterion and literature data in the Al-La-Ni system, with the region of the best glass-forming ability (GFA) and largest supercooled liquid region (ΔT x ) coinciding with the best compositional region for amorphization indicated by the λ.Δe criterion. Four new glassy compositions were found in the Al-La-Ni system, with the best predicted composition presenting the best glass-forming ability observed so far for this system. Although the λ.Δe criterion needs further refinements for completely describe the glass-forming ability in the Al-La and Al-La-Ni systems, the results demonstrated that this criterion is a good tool to predict new glass-forming compositions.

  1. Electric quadrupole moments of neutron-rich nuclei {sup 32}Al and {sup 31}Al

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, D., E-mail: kameda@ribf.riken.jp; Ueno, H. [RIKEN Nishina Center (Japan); Asahi, K.; Nagae, D.; Takemura, M.; Shimada, K. [Tokyo Institute of Technology, Department of Physics (Japan); Yoshimi, A.; Nagatomo, T.; Sugimoto, T. [RIKEN Nishina Center (Japan); Uchida, M.; Arai, T.; Takase, K.; Suda, S.; Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Murata, J.; Kawamura, H. [Rikkyo University, Department of Physics (Japan); Watanabe, H. [Australian National University, Department of Nuclear Physics (Australia); Kobayashi, Y.; Ishihara, M. [RIKEN Nishina Center (Japan)

    2007-11-15

    The electric quadrupole moments for the ground states of {sup 32}Al and {sup 31}Al have been measured by the {beta} ray-detected nuclear quadrupole resonance method. Spin-polarized {sup 32}Al and {sup 31}Al nuclei were obtained from the fragmentation of {sup 40}Ar projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal {alpha}-Al{sub 2}O{sub 3} stopper. The measured Q moment of {sup 32}Al, |Q({sup 32}Al)| = 24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of {sup 31}Al is considerably smaller than the sd calculations.

  2. The constitution of alloys in the Al-rich corner of the Al-Si-Sm ternary system

    International Nuclear Information System (INIS)

    Markoli, B.; Spaic, S.; Zupanic, F.

    2001-01-01

    The constitution of alloys and the liquidus surface in the Al-rich corner of the Al-Si-Sm ternary system were determined by the examination of controlled heated and cooled specimens, as well as heat-treated specimens by means of optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal analysis and X-ray diffraction. The Al-rich corner of the Al-Si-Sm ternary system comprises five regions of primary crystallisation (α Al , β Si , Al 3 Sm, Al 2 Si 2 Sm and AlSiSm) with following characteristic invariant reaction sequences: ternary eutectic reaction L → α Al + β Si + Al 2 Si 2 Sm, and two liquidus transition reactions, i. e., L + Al 3 Sm → α Al + AlSiSm, and L + AlSiSm → α Al + Al 2 Si 2 Sm. Along with the position of ternary eutectic and both interstitial points in the Al-rich corner of the Al-Si-Sm ternary system, the temperatures for each reaction were determined. (orig.)

  3. Disordered crystal structure of 20H-AlON, Al10O3N8

    International Nuclear Information System (INIS)

    Banno, Hiroki; Funahashi, Shiro; Asaka, Toru; Hirosaki, Naoto; Fukuda, Koichiro

    2015-01-01

    The disordered crystal structure of 20H-AlON (Al 10 O 3 N 8 ) was determined by combined use of X-ray powder diffraction and transmission electron microscopy. The title compound is hexagonal with space group P6 3 /mmc (Z=2) and the unit-cell dimensions are a=0.307082(5) nm, c=5.29447(8) nm and V=0.432376(12) nm 3 . The structural model showed the positional disordering of three of the six Al sites in the unit cell. The reliability indices calculated from the Rietveld method were R wp =6.97%, S (=R wp /R e )=1.68, R p =5.45%, R B =5.13% and R F =4.56%. We interpreted the disordered structure of 20H-AlON as a statistical average of six different types of ordered structural configurations, which are composed of an octahedral [Al(O, N) 6 ] layer and tetrahedral [Al(O, N) 4 ] layers. We demonstrated the high correlations between the hexagonal unit-cell dimensions and the octahedral layer concentrations for AlON and SiAlON polytypoids. - Graphical abstract: Variations of a and c/(n O +n T ) with n O /(n O +n T ). The a and c are the hexagonal unit-cell dimensions of AlON, SiAlON and AlN. The n O and n T are, respectively, the numbers of octahedral and tetrahedral layers in the unit cells. The unit-cell dimensions in literature are plotted in black plus for AlON and black cross for SiAlON. The unit-cell dimensions of AlN are a=0.3110 nm and c=0.4980 nm. - Highlights: • Crystal structure of Al10O3N8 is determined by laboratory X-ray powder diffraction. • The atom arrangements are represented by the split-atom model. • Six types of ordered atom arrangements are derived from the disordered structure. • Hexagonal unit-cell dimensions changed systematically for AlON and SiAlON compounds

  4. 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

  5. FRACTIONAL RECRYSTALLIZATION KINETICS IN DIRECTLY COLD ROLLED Al-Mg, Al-Mg-Sc AND Al-Mg-Sc-Zr ALLOY

    Directory of Open Access Journals (Sweden)

    M. S. Kaiser

    2014-12-01

    Full Text Available The evaluation of texture as a function of recrystallization has been characterized for directly cold rolled Al-6Mg, Al-6Mg-0.4Sc and Al-6Mg-0.4Sc-0.2Zr alloys. Samples were annealed isothermally at 400 °C for 1 to 240 minutes to allow recrystallization. Recrystallization kinetics of the alloys is analyzed from the micro-hardness variation. Isothermally annealed samples of aluminum alloys were also studied using JMAK type analysis to see if there exists any correlation between the methods. Recrystallization fraction behavior between two methods the scandium added alloys show the higher variation due to precipitation hardening and higher recrystallization behavior. The scandium and zirconium as a combined shows the more variation due to formation of Al3(Sc, Zr precipitate. From the microstructure it is also observed that the base Al-Mg alloy attained almost fully re-crystallized state after annealing at 400 °C for 60 minutes

  6. Chemical failure modes of AlQ3-based OLEDs: AlQ3 hydrolysis.

    Science.gov (United States)

    Knox, John E; Halls, Mathew D; Hratchian, Hrant P; Schlegel, H Bernhard

    2006-03-28

    Tris(8-hydroxyquinoline)aluminum(III), AlQ3, is used in organic light-emitting diodes (OLEDs) as an electron-transport material and emitting layer. The reaction of AlQ3 with trace H2O has been implicated as a major failure pathway for AlQ3-based OLEDs. Hybrid density functional calculations have been carried out to characterize the hydrolysis of AlQ3. The thermochemical and atomistic details for this important reaction are reported for both the neutral and oxidized AlQ3/AlQ3+ systems. In support of experimental conclusions, the neutral hydrolysis reaction pathway is found to be a thermally activated process, having a classical barrier height of 24.2 kcal mol(-1). First-principles infrared and electronic absorption spectra are compared to further characterize AlQ3 and the hydrolysis pathway product, AlQ2OH. The activation energy for the cationic AlQ3 hydrolysis pathway is found to be 8.5 kcal mol(-1) lower than for the neutral reaction, which is significant since it suggests a role for charge imbalance in promoting chemical failure modes in OLED devices.

  7. 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.

  8. Optical, structural, and nuclear scientific studies of AlGaN with high Al composition

    Science.gov (United States)

    Lin, Tse Yang; Chung, Yee Ling; Li, Lin; Yao, Shude; Lee, Y. C.; Feng, Zhe Chuan; Ferguson, Ian T.; Lu, Weijie

    2010-08-01

    AlGaN epilayers with higher Al-compositions were grown by Metalorganic Chemical Vapor Deposition (MOCVD) on (0001) sapphire. Trimethylgallium (TMGa), trimethylaluminium (TMAl) and NH3 were used as the source precursors for Ga, Al, and N, respectively. A 25 nm AlN nucleation layer was first grown at low-temperature of 590 °C at 300 Torr. Followed, AlxGa1-xN layers were grown at 1080 °C on low-temperature AlN nucleation layers. The heterostructures were characterized by a series of techniques, including x-ray diffraction (XRD), Rutherford backscattering (RBS), photoluminescence (PL), scanning electron microscopy (SEM) and Raman scattering. Precise Al compositions were determined through XRD, RBS, and SEM combined measurements. Room Temperature Raman Scattering spectra shows three major bands from AlGaN alloys, which are AlN-like, A1 longitudinal optical (LO) phonon modes, and E2 transverse optical (TO) band, respectively, plus several peak comes from the substrate. Raman spectral line shape analysis lead to an optical determination of the electrical property free carrier concentration of AlGaN. The optical properties of AlGaN with high Al composition were presented here.

  9. Ion-beam mixing and thermal annealing of Al--Nb and Al--Ta thin films

    International Nuclear Information System (INIS)

    Rai, A.K.; Bhattacharya, R.S.; Mendiratta, M.G.; Subramanian, P.R.; Dimiduk, D.M.

    1988-01-01

    Ion-beam mixing and thermal annealing of thin, alternating layers of Al and Nb, as well as Al and Ta, were investigated by selected area diffraction and Rutherford backscattering. The individual layer thicknesses were adjusted to obtain the overall compositions as Al 3 Nb and Al 3 Ta. The films were ion mixed with 1 MeV Au + ions at a dose of 1 x 10 16 ions cm/sup -2/ . Uniform mixing and amorphization were achieved for both Al--Nb and Al--Ta systems. Equilibrium crystalline Al 3 Nb and Al 3 Ta phases were formed after annealing of ion mixed amorphous films at 400 0 C for 6 h. Unmixed films, however, remained unreacted at 400 0 C for 1 h. Partial reaction was observed in the unmixed film of Al--Nb at 400 0 C for 6 h. After annealing at 500 0 C for 1 h, a complete reaction and formation of Al 3 Nb and Al 3 Ta phases in the respective films were observed. The influence of thermodynamics on the phase formation by ion mixing and thermal annealing is discussed

  10. Effect of elevated Al and pH on the growth and root morphology of Al-tolerant and Al-sensitive wheat seedlings in an acid soil

    Directory of Open Access Journals (Sweden)

    Md. Toufiq Iqbal

    2014-03-01

    Full Text Available Aluminium ion (Al3+ toxicity and hydrogen ion (H+ activity are the major constraints for plant growth in acid soil. This study was undertaken to determine the effect of pH and Al on the growth response and changes in root morphology of Al-tolerant (ET8 and Al-sensitive (ES8 wheat seedlings. Different levels of AlCl3 and CaCO3 were added to the soils to manipulate soil pH and extractable Al. The results showed that the bulk soil pH remained constant at pH 4.1 with further applications of AlCl3, and that the seedlings died at the 200 mg AlCl3/kg treatments. The ET8 seedlings responded better than the ES8 seedlings in both low and high Al and pH. The ET8 seedlings had higher root surface areas and root tip numbers than the ES8 seedlings in the Al treatment. In contrast, the ES8 had higher root diameters than the ET8 seedlings due to the elevated Al supply. Apoplast Al increased with the increase of soil available extractable Al, and declined with the decrease of soil extractable Al. The ET8 seedlings accumulated more Al in their apoplast than the ES8 seedlings. This study concluded that accumulation of Al in the apoplast is also involved in Al tolerance mechanism with the addition of organic acid exudation.

  11. Information of “Nukhbat al-dahr fi ‘aja’ib al-barr wa-al-bahr” by ad-Dimashqi about the Turkic Tribes of Dasht-i Kipchak »

    Directory of Open Access Journals (Sweden)

    Z.S. Ilyasova

    2016-12-01

    Full Text Available This article introduced into academic circulation information of such a historical source as “Nukhbat al-dahr fi ‘aja’ib al-barr wa-al-bahr” (Excerpts of Time on the Marvels of the Land and Sea on Kipchak clans and Turkic tribes of Dasht-i Kipchak. The material of the study is drawn from this source. Main scientific result of this work was the source’s translation into Russian accompanied by scientific comments. Sheikh Shams al-Din Abu Abdallah Muhammad Abu Talib al-Ansari al-Sufi al-Dimashqi was the author of this work. Some scholars have mistakenly confuse him with another chronicler named Shihab al-Din Ahmad ibn Yahya Ibn Fadlallah al-Omari al-Dimashqi. There is a widespread misconception that while writing on Kipchak clans and Turkic tribes al-Dimashqi used the data of such an author as Muhammad ibn Ibrahim ibn Yahya al-Ansari al-Qutub al-Warraq al-Vatvat, also known as Ahmad al-Tini. After had studying the manuscripts of al-Tini and al-Dimashqi, we did not notice the connection between these two authors regarding their information about Kipchak clans and Turkic tribes of Dasht-i Kipchak. After had studying the information about Kipchak clans and Turkic tribes of Dasht-i Kipchak, we put forward the theory that 16 ethnonyms previously identified as Kipchak clans, are actually the etnonyms of eight Kipchak clans and eight Turkic tribes. The article also contains the extraction from “Nukhbat al-dahr fi ‘aja’ib al-barr wa-al-bahr” regarding the geography of Dasht-i Kipchak and the countries inhabited by the Turks. The following data are unique in this source: 1. The text describes such rivers as Ceyhun (Amu Darya, Seyhun (Syr Darya, Itil (Volga, as well as Khorezm and Khazar Seas (Aral and Caspian Seas. 2. Additionally, this text lists the following Turkic peoples: al-Kharlukhiya (Karluks, al-Khirgaziya (Kyrgyz, al-Kaymakiya (Kimaks, al-Guzziya (Oguz, al-Bazhanakiya (Pechenegs, al-Tuguzguziya (Uighurs, al-Khulkhiya (?, al

  12. Studies on SiC(p) reinforced Al-Al sub 3 Ni eutectic matrix composites

    International Nuclear Information System (INIS)

    Masrom, A.K.; Foo, L.C.; Ismail, A.B.

    1996-01-01

    An investigation on processing of Al-5.69wt% Ni eutectic with SiC particulate composites is reported. The intermetallic composites are prepared by elemental powder metallurgy route and sintered at two different temperatures, i.e., 600 degree C and 620 degree C. Results show that the metal matrix was Al-Al sub 3 Ni eutectic. The phase analysis by XRD identified the presence of Al sub 3 Ni and Al as dominant phases together with silicon and Al sub 4 C sub 3 phase as minor phases. The Al sub 4 C sub 3 and Si phases are formed during sintering due to SiC-Al interface reaction. SEM micrographs also reveal the formation of microvoid surrounding the SiC particle

  13. The constitution of alloys in the Al-rich corner of the Al-Si-Sm ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Markoli, B.; Spaic, S. [Ljubljana Univ. (Slovenia). Faculty of Natural Science and Engineering; Zupanic, F. [Maribor Univ. (Slovenia). Faculty of Mechanical Engineering

    2001-09-01

    The constitution of alloys and the liquidus surface in the Al-rich corner of the Al-Si-Sm ternary system were determined by the examination of controlled heated and cooled specimens, as well as heat-treated specimens by means of optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal analysis and X-ray diffraction. The Al-rich corner of the Al-Si-Sm ternary system comprises five regions of primary crystallisation ({alpha}{sub Al}, {beta}{sub Si}, Al{sub 3}Sm, Al{sub 2}Si{sub 2}Sm and AlSiSm) with following characteristic invariant reaction sequences: ternary eutectic reaction L {yields} {alpha}{sub Al} + {beta}{sub Si} + Al{sub 2}Si{sub 2}Sm, and two liquidus transition reactions, i. e., L + Al{sub 3}Sm {yields} {alpha}{sub Al} + AlSiSm, and L + AlSiSm {yields} {alpha}{sub Al} + Al{sub 2}Si{sub 2}Sm. Along with the position of ternary eutectic and both interstitial points in the Al-rich corner of the Al-Si-Sm ternary system, the temperatures for each reaction were determined. (orig.)

  14. Electronic Structures and Bonding Properties of Ti2AlC and Ti3AlC2

    Institute of Scientific and Technical Information of China (English)

    MIN Xinmin; REN Yi

    2007-01-01

    The relation among electronic structure, chemical bond and property of Ti2AlC, Ti3AlC2 and doping Si into Ti2AlC was studied by density function and the discrete variation (DFT-DVM) method. After adding Si into Ti2AlC, the interaction between Si and Ti is weaker than that between Al and Ti, and the strengths of ionic and covalent bonds decrease both. The ionic and covalent bonds in Ti3AlC2, especially in Ti-Al, are stronger than those in Ti2AlC. Therefore, in synthesis of Ti2AlC, the addition of Si enhances the Ti3AlC2 content instead of Ti2AlC. The density of state (DOS) shows that there is mixed conductor characteristic in Ti2AlC and Ti3AlC2. The DOS of Ti3AlC2 is much like that of Ti2AlC. Ti2SixAl1-x C has more obvious tendency to form a semiconductor than Ti2AlC, which is seen from the obvious difference of partial DOS between Si and Al3p.

  15. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-02-01

    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.

  16. Deletion of ALS5, ALS6 or ALS7 increases adhesion of Candida albicans to human vascular endothelial and buccal epithelial cells

    OpenAIRE

    ZHAO, XIAOMIN; OH, SOON-HWAN; HOYER, LOIS L.

    2007-01-01

    C. albicans yeast forms deleted for ALS5, ALS6 or ALS7 are more adherent than a relevant control strain to human vascular endothelial cell monolayers and buccal epithelial cells. In the buccal and vaginal reconstituted human epithelium (RHE) disease models, however, mutant and control strains caused a similar degree of tissue destruction. Deletion of ALS5 or ALS6 significantly slowed growth of the mutant strain; this phenotype was not affected by addition of excess uridine to the culture medi...

  17. Alpha and beta stabilizer character of Al in Zr-Nb-Al alloys

    International Nuclear Information System (INIS)

    Peruzzi Bardella, A.; Bolcich, J.C.

    1987-01-01

    The T β/α+β of Zr5Nb and Zr5Nb2Al (weight %) were determined in order to observe the alpha-stabilizer character of Al in ternary Zr-Nb-Al alloys. Techniques employed were change of resistivity with temperature in dynamic experiences, and metallography of samples quenched to room temperature after isothermal annealings. The T β/α+β of the ternary resulted 17 ± 8 deg C higher than that of the binary alloy. In addition, taking into account the results of previous investigations of the transformation of beta on quenching Zr-Nb-Al alloys from the beta field to room temperature, it is concluded that the beta-stabilizer character of Nb is stronger than the alpha-stabilizer character of Al in these Zr alloys, and that the Al can have important influence on the mechanical properties by the appearance of TRIP effect. (Author) [es

  18. Insulator-semiconductor interface fixed charges in AlGaN/GaN metal-insulator-semiconductor devices with Al2O3 or AlTiO gate dielectrics

    Science.gov (United States)

    Le, Son Phuong; Nguyen, Duong Dai; Suzuki, Toshi-kazu

    2018-01-01

    We have investigated insulator-semiconductor interface fixed charges in AlGaN/GaN metal-insulator-semiconductor (MIS) devices with Al2O3 or AlTiO (an alloy of Al2O3 and TiO2) gate dielectrics obtained by atomic layer deposition on AlGaN. Analyzing insulator-thickness dependences of threshold voltages for the MIS devices, we evaluated positive interface fixed charges, whose density at the AlTiO/AlGaN interface is significantly lower than that at the Al2O3/AlGaN interface. This and a higher dielectric constant of AlTiO lead to rather shallower threshold voltages for the AlTiO gate dielectric than for Al2O3. The lower interface fixed charge density also leads to the fact that the two-dimensional electron concentration is a decreasing function of the insulator thickness for AlTiO, whereas being an increasing function for Al2O3. Moreover, we discuss the relationship between the interface fixed charges and interface states. From the conductance method, it is shown that the interface state densities are very similar at the Al2O3/AlGaN and AlTiO/AlGaN interfaces. Therefore, we consider that the lower AlTiO/AlGaN interface fixed charge density is not owing to electrons trapped at deep interface states compensating the positive fixed charges and can be attributed to a lower density of oxygen-related interface donors.

  19. 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.

  20. 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.

  1. Fracture toughness of Ti-Al3Ti-Al-Al3Ti laminate composites under static and cyclic loading conditions

    Science.gov (United States)

    Patselov, A. M.; Gladkovskii, S. V.; Lavrikov, R. D.; Kamantsev, I. S.

    2015-10-01

    The static and cyclic fracture toughnesses of a Ti-Al3Ti-Al-Al3Ti laminate composite material containing at most 15 vol % intermetallic compound are studied. Composite specimens are prepared by terminating reaction sintering of titanium and aluminum foils under pressure. The fracture of the titanium layers is quasi-cleavage during cyclic crack growth and is ductile during subsequent static loading.

  2. Minimal thermodynamic conditions in the reservoir to produce steam at the Cerro Prieto geothermal field, BC; Condiciones termodinamicas minimas del yacimiento para producir vapor en el campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2009-01-15

    Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.

  3. 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...

  4. Ti, Al

    Indian Academy of Sciences (India)

    In the present study, authors report on the effect that substrate bias voltage has on the microstructure and mechanical properties of (Ti, Al)N hard coatings deposited with cathodic arc evaporation (CAE) technique. The coatings were deposited from a Ti0.5Al0.5 powder metallurgical target in a reactive nitrogen atmosphere at ...

  5. Recubrimientos de (ti,aln sobre acero aisi 4140 por sputtering reactivo

    Directory of Open Access Journals (Sweden)

    DANNA GARCIA

    2007-01-01

    Full Text Available Empleando la técnica de Pulverización catódica con radiofrecuencia y magnetrón (Magnetron Sputtering RF, se prepararon películas de (Ti,AlN sobre sustratos de acero AISI 4140. Se utilizó un blanco formado con polvos metálicos de Ti y Al, con composición nominal 60% Ti y 40% Al (porcentaje en átomos y una razón de presiones parciales de nitrógeno - argón, PN2/PAr de 0,1 aproximadamente; la temperatura del sustrato se varió entre 260 y 330 ºC y el tiempo de deposición entre 2 y 4,5 horas para obtener películas con diferentes espesores. La composición química de las películas se determinó mediante la técnica de energía dispersada de rayos X (EDX, y su topografía mediante microscopía de fuerza atómica (AFM. Igualmente se midió micro dureza, y se determinó su comportamiento electroquímico mediante espectroscopia de impedancia electroquímica EIS y ensayos TAFEL. Las películas obtenidas presentaron granos globulares, uniformes y de pequeño diámetro, con características electroquímicas de protección al sustrato frente a procesos de corrosión.

  6. 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)

  7. First-principles study of L10 Ti-Al and V-Al alloys

    International Nuclear Information System (INIS)

    Chubb, S.R.; Papaconstantopoulos, D.A.; Klein, B.M.

    1988-01-01

    As a first step towards understanding the reduced embrittlement of L1 0 Ti-Al alloys which accompanies the introduction of small concentrations of V, we have determined from first principles, using full-potential linearized--augmented-plane-wave calculations, the equilibrium values of the structural parameters and the associated electronic structure for the stoichiometric (L1 0 ) Ti-Al (tetragonal) compound. Our calculated values of c/a and a are in good agreement with experiment. Using the same method of calculation, we have also studied the electronic structure associated with the (hypothetical) L1 0 V-Al alloy that would form when V is substituted for Ti. We find that (1) the electronic structures of these V-Al alloys are relatively insensitive to variations of c/a and a; (2) near the Ti-Al equilibrium geometry, the electronic structures of the V-Al and Ti-Al alloys are very similar; and (3) that a rigid-band model involving substitution of V for Ti can be used to gain a qualitative understanding of the reduction in c/a which accompanies the introduction of small concentrations of V. We relate the reduction in c/a to important changes in the bonding that accompany the occupation of bands immediately above the Fermi level of the stoichiometric Ti-Al compound

  8. Kinetic studies of oxidation of MgAlON and a comparison of the oxidation behaviour of AlON, MgAlON, O'SiAlON-ZrO{sub 2}, and BN-ZCM ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xidong; Seetharaman, S. [Div. of Metallurgy, Royal Inst. of Tech., Stockholm (Sweden); Li Wenchao [Dept. of Physical Chemistry, Univ. of Science and Technology Beijing (USTB), Beijing, BJ (China)

    2002-06-01

    The kinetics and morphology of the oxidation process of magnesium-aluminium oxynitride (MgAlON), aluminium oxynitride (AlON), O'SiAlON-ZrO{sub 2}, and BN-ZCM have been studied in the temperature range 1373-1773 K (ZCM=30 wt% ZrO{sub 2}, 52 wt% Al{sub 2}O{sub 3} and 18 wt% 3 Al{sub 2}O{sub 3}.2 SiO{sub 2}). Oxidation experiments with powder and plate samples of the above materials have been carried out in air. MgAlON shows the best resistance to oxidation at lower temperatures (< 1473 K), whereas at higher temperatures ({proportional_to} 773 K), AlON shows the best resistance. O'SiAlON-ZrO{sub 2} shows very good oxidation resistance up to 1673 K. But its oxidation rate increases strongly above 1673 K, presumably due to the formation of liquid phase. BN-ZCM has the poorest oxidation resistance due to the evaporation of B{sub 2}O{sub 3}. The activation energies for the chemical oxidation reaction of AlON, MgAlON, and O'SiAlON-ZrO{sub 2} are 214, 330 and 260 kJ/mol, respectively. The overall diffusion activation energies for AlON, MgAlON, O'SiAlON-ZrO{sub 2} and BN-ZCM are 227, 573, 367 and 289 kJ/mol, respectively. (orig.)

  9. Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

    International Nuclear Information System (INIS)

    Qin, Gaowu W.; Ren Yuping; Huang Wei; Li Song; Pei Wenli

    2010-01-01

    Graphical abstract: Display Omitted Research highlights: The ε-AlMn phase acts as the heterogeneous nucleus of α-Mg phase during the solidification of the AZ31 Mg alloy, not the γ-Al 8 Mn 5 phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure ε-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 o C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure ε-AlMn, γ 2 -Al 8 Mn 5 or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the ε-AlMn phase in the Mn-Al alloys, not the γ 2 -Al 8 Mn 5 phase. The grain size of AZ31 Mg alloy is about 91 μm without any addition of Mn-Al alloys, but remarkably decreases to ∼55 μm with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to ∼53 μm, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 o C.

  10. Ibn Qutayba en al-Andalus. La préface à I 'Adab al-Kātib dans le commentaire d'Ibn al-Sīd al-Baṭalyawsī

    Directory of Open Access Journals (Sweden)

    Soravia, Bruna

    2004-12-01

    Full Text Available Ibn Qutayba's preface to his Adab al-kātib has been considered for centuries the most important section of this work and it has been the object of many commentaries, both in the Muslim East and West. This paper deals with Ibn al-Sīd al-Baṭalyawsī´s commentary al-Iqtiḍāb, trying to show the peculiar way in which Ibn al-Sīd develops his own critique of Ibn Qutayba's controversial thesis on the relation between orthodoxy, falsafa and kalām. At the same time, the Andalusi author works out his own conception of adab, deeply influenced by his biographical experience. Finally a full translation of Ibn Qutayba's preface is proposed, half a century after G. Lecomte's partial one.

    El prefacio de Ibn Qutayba a su Adab al-Kātib ha sido considerado durante siglos como el fragmento más importante de su obra, y ha sido objeto de muchos comentarios, tanto orientales como occidentales. Este artículo trata del comentario que Ibn al-Sīd al-Baṭalyawsī hizo de ese texto de Ibn Qutayba, e intenta mostrar la forma peculiar en que Ibn al-Sīd desarrolla su propia crítica a la polémica tesis de Ibn Qutayba sobre la relación entre ortodoxia, falsafa y kalām. Al mismo tiempo, el autor andalusí elabora su propia concepción del adab, profundamente influida por su experiencia biográfica. Para concluir, se presenta una traducción completa del prefacio de Ibn Qutayba, medio siglo después de la parcial realizada por G. Lecomte.

  11. Interview als Text vs. Interview als Interaktion

    Directory of Open Access Journals (Sweden)

    Arnulf Deppermann

    2013-09-01

    Full Text Available Das Interview ist nach wie vor das beliebteste sozialwissenschaftliche Verfahren des Datengewinns. Ökonomie der Erhebung, Vergleichbarkeit und die Möglichkeit, Einsicht in Praxisbereiche und historisch-biografische Dimensionen zu erhalten, die der direkten Beobachtung kaum zugänglich sind, machen seine Attraktivität aus. Zugleich mehren sich Kritiken, die seine Leistungsfähigkeit problematisieren, indem sie auf die begrenzte Reichweite der Explikationsfähigkeiten der Befragten, die Reaktivität der Erhebung oder die Differenz zwischen Handeln und dem Bericht über Handeln verweisen. Im Beitrag wird zwischen Ansätzen, die das Interview als Text, und solchen, die es als Interaktion verstehen, unterschieden. Nach dem Text-Verständnis werden Interviews unter inhaltlichen Gesichtspunkten analysiert und als Zugang zu einer vorgängigen sozialen oder psychischen Wirklichkeit angesehen. Das Interaktions-Verständnis versteht Interviews dagegen als situierte Praxis, in welcher im Hier und Jetzt von InterviewerInnen und Befragten gemeinsam soziale Sinnstrukturen hergestellt werden. Anhand ubiquitärer Phänomene der Interviewinteraktion – Fragen, Antworten und die Selbstpositionierung von InterviewerInnen und Befragten – werden Praktiken des interaktiv-performativen Handelns im Interview dargestellt. Ihre Relevanz für die Interviewkonstitution und ihre Erkenntnispotenziale für die Interviewauswertung werden aufgezeigt. Es wird dafür plädiert, die interaktive Konstitutionsweise von Interviews empirisch zu erforschen und methodisch konsequent zu berücksichtigen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1303131

  12. Consideraciones sobre el hidrocefalo de baja presion

    Directory of Open Access Journals (Sweden)

    E. Herskovits

    1976-12-01

    Full Text Available Se analizan las condiciones fisiopatológicas del sindrome de hidrocéfalo de presión normal. De un grupo de 21 pacientes con sintomatologia clínica correspondiente a esta entidad, se seleccionan 10 que presentan un diagnóstico clínico, radiológico y cisternográfico indudable de la entidad en estudio. Se observó que, a pesar de esta selección solamente un 50% de ellos se vió beneficiado con la colocación de una válvula de baja presión. Surge entonces la hipotésis de que este cuadro es un sindrome multicausal; que por un proceso fisiopatogenico común produce un cuadro clínico, radiológico y cisternográfico similar y que serían beneficiados únicamente aquellos enfermos en los que se soluciona el problema mecánico.

  13. Structure and phase composition of Al-Ce-Cu system alloys in range of quasi-binary Al-Al8CeCu4 section

    International Nuclear Information System (INIS)

    Belov, N.A.; Khvan, A.V.

    2007-01-01

    The phase diagram of the Al-Cu-Ce system in the quasibinary section area of Al-Al 8 CeCu 4 has been investigated by metallographic, thermal, micro-X-ray spectral and X-ray structural analyses. The parameters of the eutectic reaction L→(Al)+CeCu 4 Al 8 : T=610 Deg C were found out; the composition was 14% Cu and 7% Ce. This eutectics is of a disperse structure and the ternary compound contained is capable of fragmentation and spheroidizing in the heating process (starting from 540 Deg C). It was demonstrated that the area of optimal (Al)+CeCu 4 Al 8 eutectics-based alloy compositions was within the narrow limits. That is related to the fact that at a comparatively little variation of the Cu:Ce=2 ratio solidus sharply decreases and, as a result, the crystallization interval considerably extends [ru

  14. Structural and electrical characterization of AuPtAlTi ohmic contacts to AlGaN/GaN with varying annealing temperature and Al content

    OpenAIRE

    Fay, Mike W.; Han, Y.; Brown, Paul D.; Harrison, Ian; Hilton, K.P.; Munday, A.; Wallis, D.; Balmer, R.S.; Uren, M.J.; Martin, T.

    2008-01-01

    The effect of varying annealing temperature and Al layer thickness on the structural and electrical characteristics of AuPtAlTi/AlGaN/GaN ohmic contact structures has been systematically investigated. The relationship between annealing temperature, Al content, interfacial microstructure, surface planarity and contact resistance is\\ud examined. In particular, the presence of a detrimental low temperature Pt-Al reaction is identified. This is implicated in both the requirement for a higher Al:T...

  15. Grain refining mechanism of Al-containing Mg alloys with the addition of Mn-Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Gaowu W., E-mail: qingw@smm.neu.edu.c [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China); Ren Yuping; Huang Wei; Li Song; Pei Wenli [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Wenhu Road 3-11, Heping District, Shenyang 110004, Liaoning Province (China)

    2010-10-08

    Graphical abstract: Display Omitted Research highlights: The {epsilon}-AlMn phase acts as the heterogeneous nucleus of {alpha}-Mg phase during the solidification of the AZ31 Mg alloy, not the {gamma}-Al{sub 8}Mn{sub 5} phase. The grain refinement effect is very clear with the addition of only 0.5 wt% Mn-28Al alloy (pure {epsilon}-AlMn). The grain refinement does not deteriorate up to the holding time of 60 min at 740 {sup o}C. - Abstract: The effect of manganese on grain refinement of Al-containing AZ31 Mg alloy has been investigated by designing a series of Mn-Al alloys composed of either pure {epsilon}-AlMn, {gamma}{sub 2}-Al{sub 8}Mn{sub 5} or both of them using optical microscopy and X-ray diffraction. It is experimentally clarified that the grain refinement of the AZ31 Mg alloy is due to the existence of the {epsilon}-AlMn phase in the Mn-Al alloys, not the {gamma}{sub 2}-Al{sub 8}Mn{sub 5} phase. The grain size of AZ31 Mg alloy is about 91 {mu}m without any addition of Mn-Al alloys, but remarkably decreases to {approx}55 {mu}m with the addition of either Mn-34 wt% Al or Mn-28 wt% Al. With a minor addition of 0.5 wt% Mn-28Al alloy, the grain size of AZ31 alloy decreases to {approx}53 {mu}m, and the Mn-28Al alloy can be active as grain refiner for holding time up to 60 min for the melt AZ31 alloy at 750 {sup o}C.

  16. Presentación

    Directory of Open Access Journals (Sweden)

    HC Presentación

    2010-02-01

    Full Text Available Los volúmenes de Studia Histórica (Historia Contemporánea reciben al lector con un comentario del Consejo de Redacción sobre su contenido. Reiterarlo en este número sería tanto como «mirar hacia otro lado» cuando el Estado de Derecho está amenazado en el País Vasco. Lo ha dicho el rector de su Universidad y profesor de Historia Contemporánea, Manu Montero: «la barbarie, la coacción terrorista, las presiones fascistas están amenazando a la democracia en el País Vasco. La democracia, nuestra democracia, está en peligro, en grave peligro. Como sucediera en los períodos más negros de nuestra historia». Nuestra mirada hoy se dirige a vosotros, a los profesores de Historia Contemporánea que hacéis del cotidiano quehacer profesional en el País Vasco un ejercicio de libertad, que mantenéis en condiciones muy difíciles la dignidad intelectual, que nos estáis dando un ejemplo impagable: hacer historia de la mejor calidad —esta entrega de Studia Histórica (Historia Contemporánea lo acredita— sin ceder al oportunismo o al miedo. Con nuestra solidaridad, nuestro agradecimiento.

  17. La depresión y su relación con el intento autolítico

    Directory of Open Access Journals (Sweden)

    José Fabián Hidrobo Guzmán

    2017-05-01

    Full Text Available El presente artículo apunta a la relación subjetiva que implica la depresión entorno al intento autolítico, con un enfoque sociológico basado en el método científico, que demuestra que la terapia emocional y conductiva cambia el sentimiento y actitudes cotidianas del individuo. Los hechos sociales, aunque son externos al individuo determinan su conducta, por lo tanto, la sociedad forma al individuo, quien tiende a comportarse según las circunstancias y el contexto en el que se encuentre presente. El termino depresión toma significaciones radicalmente diferentes en función de la cultura en que se da y está relacionada con las presiones emocionales propias de su edad, principalmente en los períodos críticos de la infancia. La prevención del intento autolítico si bien es posible, abarca un proceso de actividades socio afectivas conjuntas con las condiciones familiares y educacionales de los adolescentes con el tratamiento eficaz de los trastornos mentales, además de un control medioambiental de los factores de riesgo con información apropiada del problema, constituyen elementos esenciales de los programas de prevención.

  18. Natural Mexican zeolite, potential material for hydrogen storage; Zeolita natural mexicana, material para su posible uso en el almacenamiento de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe-Garcia, J. L.; Lopez Munoz, B. E. [Instituto Nacional de Investigaciones Nucleares (Mexico)]. E-mail: joseluis.iturbe@inin.gob.mx

    2009-09-15

    seguida, se disminuyo la temperatura a 10 grados Celsios y se puso en contacto con hidrogeno de ultra alta pureza a una presion de 10 bares durante 10 minutos. El analisis de hidrogeno atrapado en la zeolita se realizo mediante cromatografia de gases. Los resultados por medio de los cromatogramas indican que la zeolita adsorbio y libero al hidrogeno en condiciones totalmente distintas a lo reportado en la literatura, es decir, que en nuestras condiciones experimentales a baja presion y temperatura, el hidrogeno queda sorbido en este tipo de material.

  19. AYAT-AYAT WAH}DAT AL-WUJUd dalam Kitab Tanbi>h al-Ma>shi Karya ‘Abdurrauf al-Sinkili

    Directory of Open Access Journals (Sweden)

    Asep Nahrul Musadad

    2015-08-01

    Full Text Available Abstract: One of the key moments in discussing the history of Indonesian Islam is a polemic related to the negotiation on the doctrine of wahdat al-wujud that occured in Aceh in 17th century between the followers of Hamzah al-Fansuri and Nuruddin al-Raniri. This article focuses on analyzing several Qur’anic verses used by ‘Abdurrauf as the confirmation of his argument. In the polemical context, Abdurrauf al-Sinkili appeared to be an actor of reconciliation between two opposite sides. He tried to respond to the disputed issues through his book called “Tanbi>h al-Mashi”. As an exponent of the so-called moderate sufism (mysticism, he built the argument concerning wah}dat al-wujud based on the Quranic text. After making a thematic classification chronologically, his interpretation on these verses is analyzed by using Hussain al-Dhahaby’s theory of sufistic exegesis. In conclusion, it shows that ‘Abdurrauf’s commentary is “sufi-nazari type”, featured by his exegeses pattern. This, of course, represents his attitude as a reconciler who then needs to seek confirmation to the Qur’anic verses in evaluating wah}dat al-wujud doctrine, through which such a polemical issues occurred at that time. الملخص: إن من المرحلة الأساسية التي مرّ بها تاريخ الإسلام في اندونيسيا الجدل و النزاع حول عقيدة وحدة الوجود فى أتشيه (Aceh حول قرن السابع عشر بين أتباع حمزة الفنسوري و نور الدين الرانيري. ففي ذلك الخطاب النزاعي جاء عبد الرؤوف السنكيلي مصلحا بين الجانبين المعاكسين. وعلى مقتضى الظروف، كتب كتاب " تنبيه الماشي" الذي تطرّق فيه طريق التوسّط، ممثّلا للتصوّف المعتدل. اعتمد عبد الرؤوف على النصوص القرآنية فى تحقيق آراءه حول ت

  20. Reviewing Medical Education in KamelAl-Senaat Al-Tebieh

    Directory of Open Access Journals (Sweden)

    Shahla Moradi

    2017-06-01

    Full Text Available Background and Objective: Among the human sciences, medicine is superior to all other sciences. One of the effective factors in education, especially in medical education is using appropriate textbooks. This study aims to consider a classic book of medical education and find its relevance to modern medicine. Materials and Methods: Reviewing and analyzing parts of Kamel Al-Senaat Al-Tebieh medical textbook. Results: This book has about four hundred thousand words and it was divided into twenty articles, each consisting of several chapters, first ten topics of which are about theoretical medicine, and others are information related to practical medicine. Conclusion: One of the most important obligations of every nation is to protect and preserve written and unwritten cultural and scientific resources Kamel Al-Senaat Al-Tebieh was written in one of the glorious periods of Iranian Medical History by Ali Ibn Abbas. It has a dignified position because of its recording method. This method is one of the best methods that is used after Ahvazi. Even today it is a valuable source of medical education.

  1. Density and atomic volume in liquid Al-Fe and Al-Ni binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Plevachuk, Yu. [Ivan Franko National Univ., Lviv (Ukraine). Dept. of Metal Physics; Egry, I.; Brillo, J.; Holland-Moritz, D. [Deutsches Zentrum fuer Luft- und Raumfahrt, Koeln (Germany). Inst. fuer Raumsimulation; Kaban, I. [Chemnitz Univ. of Technolgy (Germany). Inst. of Physics

    2007-02-15

    The density of liquid Al-Fe and Al-Ni binary alloys have been determined over a wide temperature range by a noncontact technique combining electromagnetic levitation and optical dilatometry. The temperature and composition dependences of the density are analysed. A negative excess volume correlates with the negative enthalpy of mixing, compound forming ability and chemical short-range ordering in liquid Al-Fe and Al-Ni alloys. (orig.)

  2. TEM characterization of Al-C-Cu-Al2O3 composites produced by mechanical milling

    International Nuclear Information System (INIS)

    Santos-Beltran, A.; Gallegos-Orozco, V.; Estrada-Guel, I.; Bejar-Gomez, L.; Espinosa-Magana, F.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2007-01-01

    Novel Al-based composites (Al-C-Cu-Al 2 O 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 2 O 3 nanofibers were found in as-sintered products, as determined by EELS. C and Cu react with Al to crystallize in Al 3 C 4 and Al 2 Cu structures, respectively

  3. Formation of AlFeSi phase in AlSi12 alloy with Ce addition

    Directory of Open Access Journals (Sweden)

    S. Kores

    2012-04-01

    Full Text Available The influence of cerium addition on the solidification sequence and microstructure constituents of the Al-Si alloys with 12,6 mass % Si was examined. The solidification was analyzed by a simple thermal analysis. The microstructures were examined with conventional light and scanning electron microscopy. Ternary AlSiCe phase was formed in the Al-Si alloys with added cerium during the solidification process. AlSiCe and β-AlFeSi phases solidified together in the region that solidified the last. Cerium addition influenced on the morphology of the α-AlFeSi phase solidification.

  4. Compressive performance and crack propagation in Al alloy/Ti{sub 2}AlC composites

    Energy Technology Data Exchange (ETDEWEB)

    Hanaor, D.A.H., E-mail: dorian.hanaor@sydney.edu.au [School of Civil Engineering, University of Sydney, Sydney, NSW 2006 (Australia); Hu, L. [Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011 (United States); Kan, W.H.; Proust, G. [School of Civil Engineering, University of Sydney, Sydney, NSW 2006 (Australia); Foley, M. [Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW 2006 (Australia); Karaman, I.; Radovic, M. [Department of Materials Science and Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2016-08-30

    Composite materials comprising a porous Ti{sub 2}AlC matrix and Al 6061 alloy were fabricated by a current-activated pressure assisted melt infiltration process. Coarse, medium and fine meso-structures were prepared with Al alloy filled pores of differing sizes. Materials were subjected to uniaxial compressive loading up to stresses of 668 MPa, leading to the failure of specimens through crack propagation in both phases. As-fabricated and post-failure specimens were analysed by X-ray microscopy and electron microscopy. Quasi-static mechanical testing results revealed that compressive strength was the highest in the fine structured composite materials. While the coarse structured specimens exhibited a compressive strength of 80% relative to this. Reconstructed micro-scale X-ray tomography data revealed different crack propagation mechanisms. Large planar shear cracks propagated throughout the fine structured materials while the coarser specimens exhibited networks of branching cracks propagating preferentially along Al alloy-Ti{sub 2}AlC phase interfaces and through shrinkage pores in the Al alloy phase. Results suggest that control of porosity, compensation for Al alloy shrinkage and enhancement of the Al alloy-Ti{sub 2}AlC phase interfaces are key considerations in the design of high performance metal/Ti{sub 2}AlC phase composites.

  5. Phase equilibria and crystalline structure of compounds in the Lu-Al and Lu-Cu-Al systems

    International Nuclear Information System (INIS)

    Kuz'ma, Yu.B.; Stel'makhovich, B.M.; Galamushka, L.I.

    1992-01-01

    Phase equilibria and crystal structure of compounds in Lu-Al and Lu-Cu-Al systems were studied. Existence of Lu 2 Al compound having the structure of the PbCl 2 type is ascertained. Diagram of phase equilibria of Lu-Cu-Al system at 870 K is plotted. Compounds Lu 2 (Cu,Al) 17 (the Th 2 Zn 17 type structure), Lu(Cu,Al) 5 (CaCu 5 type structure), Lu 6 (Cu,Al) 23 (Th 6 Mn 23 type structure) and ∼ LuCuAl 2 have been prepared for the first time. Investigation of component interaction in Lu-Cu-Al system shows that the system is similar to previously studied systems Dy-Cu-Al and Er-Cu-Al. The main difference consists in the absence of LuCuAl 3 compound with rhombic structure of the CeNi 2+x Sb 2-x type in the system investigated

  6. Al Qaeda in the Arabian Peninsula (AQAP): An Al Qaeda Affiliate Case Study

    Science.gov (United States)

    2017-10-01

    Villarosa, Al-Qaeda in Yemen, Carnegie Endowment, July 7, 2009, http://carnegieendowment.org/2009/07/07/Al-Qaeda-in-yemen- event-1372. 53 Brian Whitaker...73 Khaled Fattah, “Yemen’s Insecurity Dilemma,” Yemen Times, February 11, 2014, http:// carnegie -mec.org/2014/02...Johnsen, and Shari Villarosa, “Al-Qaeda in Yemen.” Carnegie Endowment. July 7, 2009. http://carnegieendowment.org/2009/07/07/Al-Qaeda-in- yemen-event

  7. Determination of forces induced by steam flow in turbines; Determinacion de fuerzas inducidas por flujo de vapor en turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Castrejon, Juan Carlos

    2008-09-15

    que usan geometrias simplificadas en 2D y caracteristicas de flujo promedio, y no toman en cuenta la geometria real de las turbinas ni consideran que el flujo sea no homogeneo. Ademas con el MCDF se obtiene que las fuerzas inducidas son ondulatorias (cambian en su magnitud con respecto al tiempo), otros metodos de calculo solo muestran una fuerza constante en el tiempo. Finalmente el estudio de la presion en el claro axial tobera-rotor mostro que cuando los alabes estan en movimiento, el campo de flujo para una region dada del claro es completamente ondulatorio con sus picos o valles en fase. Cambiando solo la amplitud de las ondas. Pero instantaneamente el campo de presion tienen una forma diferente alturas, asi como tambien el numero de picos y valles en cada perfil cambia en el sentido del claro.

  8. Formation of epitaxial Al 2O 3/NiAl(1 1 0) films: aluminium deposition

    Science.gov (United States)

    Lykhach, Y.; Moroz, V.; Yoshitake, M.

    2005-02-01

    Structure of epitaxial Al 2O 3 layers formed on NiAl(1 1 0) substrates has been studied by means of reflection high-energy electron diffraction (RHEED). The elucidated structure was compared to the model suggested for 0.5 nm-thick Al 2O 3 layers [K. Müller, H. Lindner, D.M. Zehner, G. Ownby, Verh. Dtsch. Phys. Ges. 25 (1990) 1130; R.M. Jaeger, H. Kuhlenbeck, H.J. Freund, Surf. Sci. 259 (1991) 235]. The stepwise growth of Al 2O 3 film, involving deposition and subsequent oxidation of aluminium onto epitaxial 0.5 nm-thick Al 2O 3 layers, has been investigated. Aluminium was deposited at room temperature, whereas its oxidation took place during annealing at 1070 K. The Al 2O 3 thickness was monitored by means of Auger electron spectroscopy (AES). It was found that Al 2O 3 layer follows the structure of 0.5 nm thick Al 2O 3 film, although a tilting of Al 2O 3(1 1 1) surface plane with respect to NiAl(1 1 0) surface appeared after Al deposition.

  9. Amyotrophic lateral sclerosis (ALS)

    Science.gov (United States)

    Lou Gehrig disease; ALS; Upper and lower motor neuron disease; Motor neuron disease ... One out of 10 cases of ALS is due to a genetic defect. The cause is unknown in most other cases. In ALS, motor nerve cells (neurons) waste away ...

  10. 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

  11. Oxidation behavior of Al/Cr coating on Ti2AlNb alloy at 900 °C

    Science.gov (United States)

    Yang, Zhengang; Liang, Wenping; Miao, Qiang; Chen, Bowen; Ding, Zheng; Roy, Nipon

    2018-04-01

    In this paper, the Al/Cr coating was fabricated on the surface of Ti2AlNb alloy via rf magnetron sputtering and double glow treatment to enhance oxidation resistance. The protective coating with an outer layer of Al and inner layer of Cr has great bonding strength due to the in-diffusion of Cr and the inter-diffusion between Al and Cr to form Al-Cr alloyed layer which has great hardness. Acoustic emission curve which was detected via WS-2005 scratch tester indicates the bonding strength between Al/Cr coating and substrate is great. Morphology of Ti2AlNb alloy with Al/Cr coating after scratch test shows that the scratch is smooth without disbanding, and the depth and breadth of scratch are changed uniformly. The mass change was reduced after oxidation test due to the Al/Cr protective coating. Isothermal oxidation test at 900 °C was researched. Results indicate that Al/Cr coating provided oxidation resistance of Ti2AlNb alloy with prolonged air exposure at 900 °C. Al2O3 was detected by XRD patterns and SEM images, and was formed on the surface of Ti2AlNb alloy to protect substrate during oxidation test. A certain content of Cr is beneficial for the formation of Al2O3. Besides, Cr2O3 was produced under Al2O3 by outward diffusion of Cr to protect substrate sequentially, no cracks were discovered on Al/Cr protective coating. The process of Ti outward diffusion into surface was suppressive due to integration of Cr-Ti and Al-Ti intermetallics. A steady, adherent and continuous coated layer of Al/Cr on Ti2AlNb alloy increases oxidation resistance.

  12. ¿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.

  13. Investigation of annealing treatment on the interfacial properties of explosive-welded Al/Cu/Al multilayer

    International Nuclear Information System (INIS)

    Honarpisheh, M.; Asemabadi, M.; Sedighi, M.

    2012-01-01

    Highlights: ► We studied explosive-welded Al/Cu/Al multilayer. ► We investigated heat treatment influence on the bond properties of Al/Cu/Al. ► Intermetallic compounds were studied using the SEM, OM and EDS analysis. ► Variations of hardness in the thickness were investigated using micro-hardness. ► Intermetallic phases such as AlCu 3 and Al 2 C create at the interface of Al/Cu/Al. -- Abstract: In this study, an Al/Cu/Al multilayer sheet was fabricated by explosive welding process and the effects of annealing temperature on the interfacial properties of explosively bonded Al/Cu bimetal have been investigated. For this purpose, hardness changes along the thickness of the samples have been measured, and the thickness and type of intermetallic compounds formed at the joining interface have been explored by means of optical microscopy (OM), scanning electron microscopy (SEM) and also energy dispersive spectroscopy (EDS). The obtained results indicate that, with the increase of the annealing temperature, the thickness of intermetallic compounds has increased and the amount of hardness along the thickness of the joining interface has diminished. In the annealed sample at 400 °C for 30 min, it was observed that intermetallic layers have formed at the interface of Al/Cu bimetals. These layers consist of the intermetallic compounds AlCu 3 , Al 2 Cu and AlCu, and their thickness gets to about 5 μm at some points. The examinations performed by the SEM, following the Vickers micro-hardness test, indicated the existence of a number of microcracks at the top and bottom interface of the sample annealed at 400 °C. This shows the formation of brittle intermetallic compounds at the joining interface, and also indicates the low ductility of these compounds.

  14. NMR evidence for Co-Al-Co molecular groups trapped in cages of Co4Al13

    International Nuclear Information System (INIS)

    Jeglic, P.; Heggen, M.; Feuerbacher, M.; Bauer, B.; Gille, P.; Haarmann, F.

    2009-01-01

    We present the results of 27 Al nuclear magnetic resonance (NMR) experiments on the phase Co 4 Al 13 . These results are compared to a recent structure model [1], which demonstrates a unique bonding for Al atoms in the Co-Al-Co molecular groups. In our measurement, two 27 Al signals were identified. The first one originates from Al atoms forming cages. The second signal corresponds to Al sites with exceptionally large almost axially symmetric quadrupole coupling. This finding is in perfect agreement with isolated Co-Al-Co molecular groups in accordance to Ref. [1].

  15. The Y-Cu-Al system

    International Nuclear Information System (INIS)

    Krachan, T.; Stel'makhovych, B.; Kuz'ma, Yu.

    2003-01-01

    The phase diagram of the Y-Cu-Al system at 820 K has been constructed using X-ray powder diffraction. The existence of earlier known ternary aluminides has been confirmed and their homogeneity regions and atomic distributions in the structures have been determined: YCu 4.6-4.0 Al 7.4-8.0 (ThMn 12 -type R I =0.049), Y 2 Cu 12.0-10.5 Al 5.0-6.5 (Th 2 Zn 17 -type R I =0.092), YCu 1.0-1.1 Al 1.0-0.9 (Fe 2 P-type R I =0.068). It has been shown that the structure of Y(Cu,Al) 3 is characterized by an ordered distribution of the Cu and Al atoms and it should be referred as Ca 3 Cu 2 Al 7 structure type (R I =0.060) besides the PuNi 3 structure type with statistical occupancies of the smaller atoms. At the investigated temperature the compound YCu 1.0-0.25 Al 3.0-3.75 (BaAl 4 -type) was not observed. However, we found the ternary aluminide with composition Y 3 Cu 2.7-2.0 Al 8.3-9.0 and related La 3 Al 11 -type (space group Immm, a=0.4192-0.4228, b=1.2423-1.2557, c=0.9812-0.9895 nm, R I =0.069). The compounds YCu 6.8 Al 4.2 (space group Fddd, Tb(Cu 0.58 Al 0.42 ) 11 -type, a=1.42755, b=1.48587, c=0.65654 nm, R I =0.062) and YCu 6.5 Al 4.5 (space group I4 1 /amd, BaCd 11 -type, a=1.02774, c=0.65838 nm, R I =0.071) have been found and structurally refined for the first time

  16. Preparation, deformation, and failure of functional Al-Sn and Al-Sn-Pb nanocrystalline alloys

    Science.gov (United States)

    Noskova, N. I.; Vil'Danova, N. F.; Filippov, Yu. I.; Churbaev, R. V.; Pereturina, I. A.; Korshunov, L. G.; Korznikov, A. V.

    2006-12-01

    Changes in the structure, hardness, mechanical properties, and friction coefficient of Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb (wt %) alloys subjected to severe plastic deformation by equal-channel angular pressing (with a force of 40 tonne) and by shear at a pressure of 5 GPa have been studied. The transition into the nanocrystalline state was shown to occur at different degrees of plastic deformation. The hardness exhibits nonmonotonic variations, namely, first it increases and subsequently decreases. The friction coefficient of the Al-30% Sn, Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys quenched from the melt was found to be 0.33; the friction coefficients of these alloys in the submicrocrystalline state (after equal-channel angular pressing) equal 0.24, 0.32, and 0.35, respectively. The effect of disintegration into nano-sized powders was found to occur in the Al-15% Sn-25% Pb, and Al-5% Sn-35% Pb alloys after severe plastic deformation to ɛ = 6.4 and subsequent short-time holding.

  17. Characterization of Al/Ni multilayers and their application in diffusion bonding of TiAl to TiC cermet

    International Nuclear Information System (INIS)

    Cao, J.; Song, X.G.; Wu, L.Z.; Qi, J.L.; Feng, J.C.

    2012-01-01

    The Al/Ni multilayers were characterized and diffusion bonding of TiAl intermetallics to TiC cermets was carried out using the multilayers. The microstructure of Al/Ni multilayers and TiAl/TiC cermet joint was investigated. The layered structures consisting of a Ni 3 (AlTi) layer, a Ni 2 AlTi layer, a (Ni,Al,Ti) layer and a Ni diffusion layer were observed from the interlayer to the TiAl substrate. Only one AlNi 3 layer formed at the multilayer/TiC cermet interface. The reaction behaviour of Al/Ni multilayers was characterized by means of differential scanning calorimeter (DSC) and X-ray diffraction. The initial exothermic peak of the DSC curve was formed due to the formation of Al 3 Ni and Al 3 Ni 2 phases. The reaction sequence of the Al/Ni multilayers was Al 3 Ni → Al 3 Ni 2 → AlNi → AlNi 3 and the final products were AlNi and AlNi 3 phases. The shear strength of the joint was tested and the experimental results suggested that the application of Al/Ni multilayers improved the joining quality. - Highlights: ► Diffusion bonding of TiAl to TiC cermet was realized using Al/Ni multilayer. ► The reaction sequence of the Al/Ni multilayers was Al 3 Ni → Al 3 Ni 2 → AlNi → AlNi 3 . ► The interfacial microstructure of the joint was clarified. ► The application of Al/Ni multilayers improved the joining quality.

  18. 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 coating 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.

  19. 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.

  20. Some aspects of anelastic and microplastic creep of pure Al and two Al-alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sgobba, S. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland)); Kuenzi, H.U. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland)); Ilschner, B. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland))

    1993-11-01

    Anelastic creep of pure Al, commercial Al-Cu and a binary Al-Cu alloy has been measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was also quantified from measurements of the anelastic creep recovery. The dependence of the deformation-time curves on thermal treatment and cold work is analyzed. The mechanisms responsible for the room temperature anelastic creep are discussed. Materials loaded below their elastic limit can present either a pure anelastic behavior (commercial Al-Cu) or additional viscoelastic creep (pure Al, high purity Al-Cu). For commercial Al-Cu, the presence of an irreversible deformation appears to be mainly related to the state of the surface. A viscoelastic after effect has been measured for this alloy after a Cu-electroplating treatment. As a typical result for room temperature creep, the irreversible deformation depends logarithmically on load time. (orig.).

  1. Some aspects of anelastic and microplastic creep of pure Al and two Al-alloys

    International Nuclear Information System (INIS)

    Sgobba, S.; Kuenzi, H.U.; Ilschner, B.

    1993-01-01

    Anelastic creep of pure Al, commercial Al-Cu and a binary Al-Cu alloy has been measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was also quantified from measurements of the anelastic creep recovery. The dependence of the deformation-time curves on thermal treatment and cold work is analyzed. The mechanisms responsible for the room temperature anelastic creep are discussed. Materials loaded below their elastic limit can present either a pure anelastic behavior (commercial Al-Cu) or additional viscoelastic creep (pure Al, high purity Al-Cu). For commercial Al-Cu, the presence of an irreversible deformation appears to be mainly related to the state of the surface. A viscoelastic after effect has been measured for this alloy after a Cu-electroplating treatment. As a typical result for room temperature creep, the irreversible deformation depends logarithmically on load time. (orig.)

  2. A study of ion damage in Al, Al/Cu and Al/Ag

    International Nuclear Information System (INIS)

    Marikar, P.

    1979-06-01

    Specimens of pure aluminium, aluminium-copper and aluminium-silver have been irradiated with 20 keV helium ions and/or 100 keV aluminium ions and the nature of the damage assessed using transmission electron microscopy. Irradiation with 20 keV helium ions to a dose of 2.7 x 10 15 ions cm -2 results in the formation of interstitial loops and helium gas bubbles. The helium bubbles were detectable only after annealing at a high temperature following irradiation. When the helium preinjected aluminium specimens were irradiated with 100 keV Al + ions to a dose of 84 dpa at temperatures above 150 0 C, voids were observed to form. At a lower dose of 64 dpa, only a high density of dislocation loops was observed. Al-1 wt% Cu alloy containing partially coherent theta' precipitates resists void formation to a considerable extent, and Al-10 wt% Ag alloy containing coherent G.P. zones offers complete resistance to both dislocation loop nucleation and void formation. The experimental results are discussed in the light of the current theories of irradiation induced damage in metals. The importance of the dislocation-sink efficiency for point defects, the gaseous impurity and the alloying elements in determining void formation is highlighted. (author)

  3. Interdiffusion between U(Mo,Pt) or U(Mo,Zr) and Al or Al A356 alloy

    International Nuclear Information System (INIS)

    Komar Varela, C.; Mirandou, M.; Arico, S.; Balart, S.; Gribaudo, L.

    2009-01-01

    Solid state reactions in chemical diffusion couples U-7 wt.%Mo-0.9 wt.%Pt/Al at 580 deg. C and U-7 wt.%Mo-0.9 wt.%Pt/Al A356 alloy, U-7 wt.%Mo-1 wt.%Zr/Al and U-7 wt.%Mo-1 wt.%Zr/Al A356 alloy at 550 deg. C were characterized. Results were obtained from optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The UAl 3, UAl 4 and Al 20 Mo 2 U phases were identified in the interaction layers of γU(Mo,Pt)/Al and γU(Mo,Zr)/Al diffusion couples. Al 43 Mo 4 U 6 ternary compound was also identified in γU(Mo,Zr)/Al due to the decomposition of γU(Mo,Zr) phase. The U(Al,Si) 3 and U 3 Si 5 phases were identified in the interaction layers of γU(Mo,Pt)/Al A356 and γU(Mo,Zr)/Al A356 diffusion couples. These phases are formed due to the migration of Si to the interaction layer. In the diffusion couple U(Mo,Zr)/Al A356, Zr 5 Al 3 phase was also identified in the interaction layer. The use of synchrotron radiation at Brazilian Synchrotron Light Laboratory (LNLS, CNPq, Campinas, Brazil) was necessary to achieve a complete crystallographic characterization.

  4. CuAlO2 and CuAl2O4 thin films obtained by stacking Cu and Al films using physical vapor deposition

    Science.gov (United States)

    Castillo-Hernández, G.; Mayén-Hernández, S.; Castaño-Tostado, E.; DeMoure-Flores, F.; Campos-González, E.; Martínez-Alonso, C.; Santos-Cruz, J.

    2018-06-01

    CuAlO2 and CuAl2O4 thin films were synthesized by the deposition of the precursor metals using the physical vapor deposition technique and subsequent annealing. Annealing was carried out for 4-6 h in open and nitrogen atmospheres respectively at temperatures of 900-1000 °C with control of heating and cooling ramps. The band gap measurements ranged from 3.3 to 4.5 eV. Electrical properties were measured using the van der Pauw technique. The preferred orientations of CuAlO2 and CuAl2O4 were found to be along the (1 1 2) and (3 1 1) planes, respectively. The phase percentages were quantified using a Rietveld refinement simulation and the energy dispersive X-ray spectroscopy indicated that the composition is very close to the stoichiometry of CuAlO2 samples and with excess of aluminum and deficiency of copper for CuAl2O4 respectively. High resolution transmission electron microscopy identified the principal planes in CuAlO2 and in CuAl2O4. Higher purities were achieved in nitrogen atmosphere with the control of the cooling ramps.

  5. Three-Dimensional FIB/EBSD Characterization of Irradiated HfAl3-Al Composite

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Zilong; Guillen, Donna Post; Harris, William; Ban, Heng

    2016-09-01

    A thermal neutron absorbing material, comprised of 28.4 vol% HfAl3 in an Al matrix, was developed to serve as a conductively cooled thermal neutron filter to enable fast flux materials and fuels testing in a pressurized water reactor. In order to observe the microstructural change of the HfAl3-Al composite due to neutron irradiation, an EBSD-FIB characterization approach is developed and presented in this paper. Using the focused ion beam (FIB), the sample was fabricated to 25µm × 25µm × 20 µm and mounted on the grid. A series of operations were carried out repetitively on the sample top surface to prepare it for scanning electron microscopy (SEM). First, a ~100-nm layer was removed by high voltage FIB milling. Then, several cleaning passes were performed on the newly exposed surface using low voltage FIB milling to improve the SEM image quality. Last, the surface was scanned by Electron Backscattering Diffraction (EBSD) to obtain the two-dimensional image. After 50 to 100 two-dimensional images were collected, the images were stacked to reconstruct a three-dimensional model using DREAM.3D software. Two such reconstructed three-dimensional models were obtained from samples of the original and post-irradiation HfAl3-Al composite respectively, from which the most significant microstructural change caused by neutron irradiation apparently is the size reduction of both HfAl3 and Al grains. The possible reason is the thermal expansion and related thermal strain from the thermal neutron absorption. This technique can be applied to three-dimensional microstructure characterization of irradiated materials.

  6. The Genyornis Egg: Response to Miller et al.'s commentary on Grellet-Tinner et al., 2016

    Science.gov (United States)

    Grellet-Tinner, Gerald; Spooner, Nigel A.; Handley, Warren D.; Worthy, Trevor H.

    2017-04-01

    Williams (1981) and Williams and Rich (1991) attributed Australian Quaternary fossil eggshell that differed from that of emu Dromaius novaehollandiae to the extinct bird Genyornis newtoni without any osteological or embryonic support. Such association by proximity or abundance mirrors the case of the mistaken association of oviraptor eggs to Protoceratops in the 1920's by Andrews (Grellet-Tinner and Makovicky, 2006). No other candidate species was considered, and this attribution has been unchallenged and followed by everyone thereafter. Much research has been done on this Australian eggshell, with one result being that the extinction of the parent of this eggshell is the most well documented for a taxon in Australia (e.g., Miller et al., 1999, 2005). Grellet-Tinner et al. (2016) raised several problems with the identity of the eggshell Williams (1981) attributed to Genyornis newtoni and suggested that extinct megapodes of the genus Progura were the more likely layer of this eggshell type, therein referred to as ;putative Genyornis oological material; (PGOM). Miller et al. (2017) challenged our hypothesis stating that ;Based on the dimensions of the reconstructed Spooner Egg,Grellet-Tinner et al. (2016)argue that PGOM is too small for a bird with the body mass estimated for Genyornis (168-275 kg) … …[and] …. None of the additional PGOM observations reported byGrellet-Tinner et al. (2016)are inconsistent with a Genyornis parent;. Here we take the opportunity to respond to their critique, the basis of which resolves into a few points, which we address in turn.

  7. Characterization of Al/Ni multilayers and their application in diffusion bonding of TiAl to TiC cermet

    Energy Technology Data Exchange (ETDEWEB)

    Cao, J., E-mail: cao_jian@hit.edu.cn [State Key Lab of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin, 150001 (China); Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin, 150001 (China); Song, X.G. [State Key Lab of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin, 150001 (China); Wu, L.Z. [Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin, 150001 (China); Qi, J.L.; Feng, J.C. [State Key Lab of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin, 150001 (China)

    2012-02-29

    The Al/Ni multilayers were characterized and diffusion bonding of TiAl intermetallics to TiC cermets was carried out using the multilayers. The microstructure of Al/Ni multilayers and TiAl/TiC cermet joint was investigated. The layered structures consisting of a Ni{sub 3}(AlTi) layer, a Ni{sub 2}AlTi layer, a (Ni,Al,Ti) layer and a Ni diffusion layer were observed from the interlayer to the TiAl substrate. Only one AlNi{sub 3} layer formed at the multilayer/TiC cermet interface. The reaction behaviour of Al/Ni multilayers was characterized by means of differential scanning calorimeter (DSC) and X-ray diffraction. The initial exothermic peak of the DSC curve was formed due to the formation of Al{sub 3}Ni and Al{sub 3}Ni{sub 2} phases. The reaction sequence of the Al/Ni multilayers was Al{sub 3}Ni {yields} Al{sub 3}Ni{sub 2} {yields} AlNi {yields} AlNi{sub 3} and the final products were AlNi and AlNi{sub 3} phases. The shear strength of the joint was tested and the experimental results suggested that the application of Al/Ni multilayers improved the joining quality. - Highlights: Black-Right-Pointing-Pointer Diffusion bonding of TiAl to TiC cermet was realized using Al/Ni multilayer. Black-Right-Pointing-Pointer The reaction sequence of the Al/Ni multilayers was Al{sub 3}Ni {yields} Al{sub 3}Ni{sub 2} {yields} AlNi {yields} AlNi{sub 3}. Black-Right-Pointing-Pointer The interfacial microstructure of the joint was clarified. Black-Right-Pointing-Pointer The application of Al/Ni multilayers improved the joining quality.

  8. UNDERSTANDING THE MULTIDIMENSIONAL ISLAMIC FAITH THROUGH ‘ABD AL-GHANI AL-NABULUSI’S MYSTICAL PHILOSOPHY

    Directory of Open Access Journals (Sweden)

    Naoki Yamamoto

    2013-12-01

    Full Text Available This paper tries to present a new perspective on Islamic faith and Muslim identity to Muslim minorities who are challenged in practicing or following Islamic law in non-Islamic countries or non-Muslims in the contemporary world. It will uncover the multidimensional perspective of the concept of faith based on sin (dhanb and repentance (tawbah through the mystical philosophy of a Syrian scholar, Abd al-Ghani al-Nabulusi (d. 1143/1741 of the 18th century Ottoman Damascus who contributed to the field of Sufism particularly based on Ibn ‘Arabi’s thought of wahdat al-wujud (oneness of being and insan kamil (the perfect man. Nabulusi believes that anyone who lived during the inexistence of prophet’s revelation, inhabited an isolated place cut off from information about Islam, or lived in dar al-harb and did not make a hijra to dar al-islam could not be regarded as sinful in their deeds. However, faith in Allah is essential and infidelity is not forgiven regardless whether or not they live in dar al-islam or dar al-harb. Further, Nabulusi insists that true faith can be achieved by understanding the sin of existence; the ignorance of the difference of existence between Allah and men.  [Artikel ini menjelaskan identitas keberagamaan umat Islam minoritas yang dituntut untuk menerapkan syariat, namun harus hidup di negara non-muslim, dengan mendiskusikan perspektif multidimensional terhadap konsep dosa dan tobat seperti dikembangkan oleh Abd al-Ghanī al-Nabulusī (1143/1741, seorang sufi pemikir Syria, khususnya  wahdat al-wujūd dan insan kamil, yang hidup di masa kesultanan Usmani di Damaskus. Nabulusī berkeyakinan bahwa siapa saja yang hidup sebelum turunnya wahyu di masa Nabi, hidup di daerah terpencil yang tidak mengenal Islam, atau hidup di dar al-harb dan tidak hijrah ke dar al-islam, tidaklah dibebani dosa atas perbuatannya. Namun demikian, iman kepada Allah amatlah penting dan kekufuran tidaklah dimaafkan, baik seseorang tersebut hidup

  9. 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.``

  10. DISEÑO DE UN SISTEMA GONIOMÉTRICO CON TRES GRADOS DE LIBERTAD PARA MEDIR REFLECTANCIAS Y TEMPERATURAS RADIATIVAS EN EL SISTEMA SUELO-VEGETACIÓN

    Directory of Open Access Journals (Sweden)

    Alejandro Cano González

    2014-01-01

    Full Text Available La medición espectral multi-angular de la vegetación requiere de sistemas goniométricos costosos y pesados, difíciles de operar en condiciones de campo y laboratorio. Para facilitar este tipo de mediciones, se diseñó un sistema goniométrico (SIGO-CP simple de operar y de bajo costo, lo suficientemente flexible para ser usado en campo y laboratorio. El SIGO-CP, a diferencia de los sistemas actuales, tiene tres grados de libertad en vez de dos: acimutal, cenital y radial, permitiendo cambiar el área asociada al efecto de escala de las observaciones. El SIGO-CP fue ejemplificado en su implementación bajo condiciones de laboratorio, incluida la aplicación de eventos de precipitación con un simulador de lluvias, para experimentos de arreglos geométricos de especies vegetales en bolsas de plástico sobre las que se utiliza un fondo de suelo a la altura de los inicios de los tallos de las plantas.

  11. Rupture of Al matrix in U-Mo/Al dispersion fuel by fission induced creep

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gwan Yoon; Sohn, Dong Seong [UNIST, Daejeon (Korea, Republic of); Kim, Yeon Soo [Argonne National Laboratory, Argonnge (United States); Lee, Kyu Hong [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This phenomenon was found specifically in the dispersion fuel plate with Si addition in the Al matrix to suppress interaction layer (IL) formation between UMo and Al. It is known that the stresses induced by fission induced swelling in U-Mo fuel particles are relieved by creep deformation of the IL, surrounding the fuel particles, that has a much higher creep rate than the Al matrix. Thus, when IL growth is suppressed, the stress is instead exerted on the Al matrix. The observed rupture in the Al matrix is believed to be caused when the stress exceeded the rupture strength of the Al matrix. In this study, the possibility of creep rupture of the Al matrix between the neighboring U-Mo fuel particles was examined using the ABAQUS finite element analysis (FEA) tool. The predicted rupture time for a plate was much shorter than its irradiation life indicating a rupture during the irradiation. The higher stress leads Al matrix to early creep rupture in this plate for which the Al matrix with lower creep strain rate does not effectively relieve the stress caused by the swelling of the U-Mo fuel particles. For the other plate, no rupture was predicted for the given irradiation condition. The effect of creeping of the continuous phase on the state of stress is significant.

  12. Effect of Al and AlP on the microstructure of Mn-30 wt.%Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yuying [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jing Shi Road 73, Jinan 250061 (China); Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jing Shi Road 73, Jinan 250061 (China)], E-mail: xfliu@sdu.edu.cn

    2008-04-15

    Effect of Al and AlP particles on the microstructure of near eutectic Mn-Si alloy (Mn-30 wt.%Si) was studied by Electron Probe Micro-analyzer (EPMA) and Differential Scanning Calorimeter (DSC). Crystal lattice correspondence analyses show that both Al and AlP have good lattice matching coherence relationships with MnSi phase, and the addition of Al and AlP particles results in an abnormal eutectic structure, i.e. the eutectic constitution MnSi and Mn{sub 5}Si{sub 3} precipitate separately: MnSi precipitates firstly, and then the Mn{sub 5}Si{sub 3} phase.

  13. Elastocaloric effect in CuAlZn and CuAlMn shape memory alloys under compression

    OpenAIRE

    Qian, Suxin; Geng, Yunlong; Wang, Yi; Pillsbury, Thomas E.; Hada, Yoshiharu; Yamaguchi, Yuki; Fujimoto, Kenjiro; Hwang, Yunho; Radermacher, Reinhard; Cui, Jun; Yuki, Yoji; Toyotake, Koutaro; Takeuchi, Ichiro

    2016-01-01

    This paper reports the elastocaloric effect of two Cu-based shape memory alloys: Cu68Al16Zn16 (CuAlZn) and Cu73Al15Mn12 (CuAlMn), under compression at ambient temperature. The compression tests were conducted at two different rates to approach isothermal and adiabatic conditions. Upon unloading at a strain rate of 0.1 s−1 (adiabatic condition) from 4% strain, the highest adiabatic temperature changes (ΔTad) of 4.0 K for CuAlZn and 3.9 K for CuAlMn were obtained. The maximum stress and hystere...

  14. Formation of Al3Ti/Mg composite by powder metallurgy of Mg-Al-Ti system.

    Science.gov (United States)

    Yang, Zi R; Qi Wang, Shu; Cui, Xiang H; Zhao, Yu T; Gao, Ming J; Wei, Min X

    2008-07-01

    An in situ titanium trialuminide (Al 3 Ti)-particle-reinforced magnesium matrix composite has been successfully fabricated by the powder metallurgy of a Mg-Al-Ti system. The reaction processes and formation mechanism for synthesizing the composite were studied by differential scanning calorimetry (DSC), x-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Al 3 Ti particles are found to be synthesized in situ in the Mg alloy matrix. During the reaction sintering of the Mg-Al-Ti system, Al 3 Ti particles are formed through the reaction of liquid Al with as-dissolved Ti around the Ti particles. The formed intermetallic particles accumulate at the original sites of the Ti particles. As sintering time increases, the accumulated intermetallic particles disperse and reach a relatively homogeneous distribution in the matrix. It is found that the reaction process of the Mg-Al-Ti system is almost the same as that of the Al-Ti system. Mg also acts as a catalytic agent and a diluent in the reactions and shifts the reactions of Al and Ti to lower temperatures. An additional amount of Al is required for eliminating residual Ti and solid-solution strengthening of the Mg matrix.

  15. Al-‘Alāqah baina Ushūl al-Fiqh wa Maqāshidi al-Sharīah wa al-Da’wah ilā Ta’sīsi ‘Ilmi al-Maqāshid

    Directory of Open Access Journals (Sweden)

    Anggraini Binti Ramli

    2016-12-01

    Full Text Available The study of Maqāshid sharīa is an important point in the discussion of Islamic legal theory (ushūl al-fiqh. Serious debates began to emerge in the 19th century among Islamic jurists concerning the position of maqāshid sharīa. At least, there are three important debates in the history; first, whether maqāshid is part of the discussion ushūl al-fiqh; second, is maqāshid sharīa built upon a foundation of classical Islamic jurisprudence (fiqh; and third, whether the maqāshid sharīa study is able to become an independent science that is separated from the study of classical Islamic jurisprudence. This article tries to present a discussion of the three paradigms by employing a descriptive-analytic method. The results of this study uncover that the study of maqāshid sharīa is like two sides of one coin; theoretically it is a distinctive study from ushūl al-fiqh, but it cannot be separated from one another. Ushūl al-fiqh has become the foundation to find out more details about the study of maqashid sharia. The separation between classical Islamic jurisprudence (fiqh and maqāshid sharīa study conducted by Islamic jurists is a relative separation.

  16. Solutional Landforms of Gabal Al-Qaraha, the Oasis of Al-Hasa, Saudi Arabia

    OpenAIRE

    Embabi, Nabil S.

    1981-01-01

    Jabal Al-Qarah is one of the small outlier hills at the Oasis of Al-Hasa, lying at about lOkm ENE of Al-Hafuf Town. The solutional forms of Al-Qarah hill discussed in this paper are as follows : 1. A calcareous duricrust which covers the top and some of the slopes of the hill. 2. Rock Pillars which are long columns of white lime-stone. 3. Huge crevasses which are wide erosional openings along vertical joints. 4. Narrow, sinuous caves inside the hill. 5. Pedestal rocks with mushroo...

  17. Comparison on the interaction of Al3+/nano-Al13 with calf thymus DNA /salmon sperm DNA

    Science.gov (United States)

    Ma, Fei; Ma, Yue; Du, Changwen; Yang, Xiaodi; Shen, Renfang

    2015-11-01

    The conformation change, binding mode and binding site between Al3+/nano-Al13 and calf thymus DNA/salmon sperm DNA were investigated by UV-vis absorption, FTIR spectra, Raman spectroscopy and CD spectra, as well as melting curves measurement. The UV-vis spectra and circular dichroism spectra results suggested that the phosphate group structure was changed when Al3+ interacted with DNA, while the double-helix was distorted when nano-Al13 interacted with DNA. The FTIR and Raman spectroscopy revealed that the binding sites were Al3+ … PO2, Al3+ … N7/guanine PO2 … Al13 … N7-C8/guanine with calf thymus DNA, and Al3+ … N3-O2/cytosine, Al3+ … N7-C8/guanine, PO2 … Al13 … N7-C8/guanine, PO2 … Al13 … N1/adenine with salmon sperm DNA, respectively. The electrostatic binding was existed between Al3+ and DNA, and the electrostatic binding and complexing were found between nano-Al13 and DNA.

  18. Bukti Kebenaran Al-quran

    OpenAIRE

    Aliyah, Sri

    2015-01-01

    Al Quran is the greatest miracles of Muhammad SAW as the direction of humankind in order to reach eternal happiness. Scientific evidences show that Al Quran has the truth massages, although it was released far before the finding of modern sciences. The researches continue to study the truth of Al Quran an it revealed the historical fact.

  19. Sintering of (Ni,Mg)(Al,Fe)2O4 Materials and their Corrosion Process in Na3AlF6-AlF3-K3AlF6 Electrolyte

    Science.gov (United States)

    Xu, Yibiao; Li, Yawei; Yang, Jianhong; Sang, Shaobai; Wang, Qinghu

    2017-06-01

    The application of ledge-free sidewalls in the Hall-Héroult cells can potentially reduce the energy requirement of aluminum production by about 30 pct (Nightingale et al. in J Eur Ceram, 33:2761-2765, 2013). However, this approach poses great material challenges since such sidewalls are in direct contact with corrosive electrolyte. In the present paper, (Ni,Mg)(Al,Fe)2O4 materials were prepared using fused magnesia, reactive alumina, nickel oxide, and iron oxide powders as the starting materials. The sintering behaviors of specimens as well as their corrosion resistance to molten electrolyte have been investigated by means of X-ray diffraction and scanning electron microscope. The results show that after firing at temperature ranging from 1673 K (1400 °C) up to 1873 K (1600 °C), all the specimens prepared are composed of single-phase (Ni,Mg)(Al,Fe)2O4 composite spinel, the lattice parameter of which increases with increasing Fe3+ ion concentration. Increasing the iron oxide content enhances densification of the specimens, which is accompanied by the formation of homogeneously distributed smaller pores in the matrix. The corrosion tests show that corrosion layers consist of fluoride and Ni(Al,Fe)2O4 composite spinel grains are produced in specimens with Fe/Al mole ratio no more than 1, whereas dense Ni(Al,Fe)2O4 composite spinel layers are formed on the surface of the specimens with Fe/Al mole ratio more than 1. The dense Ni(Al,Fe)2O4 composite spinel layers formed improve the corrosion resistance of the specimens by inhibiting the infiltration of electrolyte and hindering the chemical reaction between the specimen and electrolyte.

  20. Synthesis of Al(OH3 Nanostructures from Al(OH3 Microagglomerates via Dissolution-Precipitation Route

    Directory of Open Access Journals (Sweden)

    Bo Yu

    2013-01-01

    Full Text Available A facile method was developed to synthesize Al(OH3 nanostructures from Al(OH3 microagglomerates by dissolution in 9.0 mol·L−1 NaOH at 115°C followed by dilution and aging of the solution at room temperature. The influence of Al(OH3 nanoseed and surfactants as sodium dodecyl sulfate (SDS, polyethylene glycol 6000 (PEG6000, and cetyltrimethylammonium bromide (CTAB on the formation of the Al(OH3 nano-structures was investigated. The experimental results indicated that the Al(OH3 microspheres composed of nanoparticles were prepared in the blank experiment, while dispersive Al(OH3 nano-particles with a diameter of 80–100 nm were produced in the presence of Al(OH3 nano-seed and CTAB.

  1. Effects of Al content on structure and mechanical properties of hot-rolled ZrTiAlV alloys

    International Nuclear Information System (INIS)

    Liang, S.X.; Yin, L.X.; Che, H.W.; Jing, R.; Zhou, Y.K.; Ma, M.Z.; Liu, R.P.

    2013-01-01

    Highlights: • Phase structure is greatly dependent on the Al content. • Intermetallic compound will precipitates while Al content is over 6.9 wt%. • Equiaxed α-phase grains present in the hot-rolled alloy with 6.9 wt% Al. • Alloys with Al content from 3.3 wt% to 5.6 wt% have good mechanical properties. - Abstract: Zirconium alloys show attractive properties for astronautic applications where the most important factors are anti-irradiation, corrosion resistance, anti-oxidant, very good strength-to-weight ratio. The effects of Al content (2.2–6.9 wt%) on structure and mechanical properties of the hot-rolled ZrTiAlV alloy samples were investigated in this study. Each sample of the hot-rolled ZrTiAlV alloys with Al contents from 2.2 wt% to 5.6 wt% is composed of the α phase and β phase, meanwhile, the relative content of the α phase increased with the Al content. However, the (ZrTi) 3 Al intermetallic compound was observed as the Al content increased to 6.9 wt%. Changes of phase compositions and structure with Al content distinctly affected mechanical properties of ZrTiAlV alloys. Yield strength of the alloy with 2.2 wt% Al is below 200 MPa. As Al content increased to 5.6 wt%, the yield strength, tensile strength and elongation of the examined alloy are 1088 MPa, 1256 MPa and 8%, respectively. As Al content further increased to 6.9 wt%, a rapid decrease in ductility was observed as soon as the (ZrTi) 3 Al intermetallic compound precipitated. Results show that the ZrTiAlV alloys with Al contents between 3.3 wt% and 5.6 wt% have excellent mechanical properties

  2. Relationship between Al content and substitution mechanism of Al-bearing anhydrous bridgmanites

    Science.gov (United States)

    Noda, M.; Inoue, T.; Kakizawa, S.

    2017-12-01

    It is considered that two substitution mechanisms, Tschermak substitution and oxygen vacancy substitution, exist in MgSiO3 bridgmanite for the incorporation of Al in anhydrous condition. Kubo and Akaogi (2000) has conducted the phase equilibrium experiment in the system MgSiO3-Al2O3, and established the phase diagram up to 28 GPa. However the careful observation in the bridgmanite shows that the chemical compositions are slightly deviated from Tschermak substitution join. The same tendency can be also observed in the run products by Irifune et al. (1996). This result indicates that pure Tschermak substitution bridgmanite cannot be stable even in the MgSiO3-Al2O3 join experiment. However, the previous studies used powder samples as the starting materials, so the absorbed water may affect the results. Therefore, we tried to conduct the experiment in the join MgSiO3-Al2O3 in extremely anhydrous condition to clarify whether the pure Tschermak substitution bridgmanite can be stable or not. In addition, we also examined the stability of oxygen vacancy bridgmanite in the extremely anhydrous condition for the comparison. The high pressure synthesis experiments were conducted at 28 GPa and 1600-1700° for 1hour using a Kawai-type multi-anvil apparatus. Four different Al content samples were prepared as the starting materials along the ideal substitution line of Tschermak (Al=0.025, 0.05, 0.1, 0.15 mol) and oxygen-vacancy (Al=0.025, 0.05, 0.075, 0.1 mol) substitutions, respectively (when total cation of 2). The glass rods were used as the starting materials to eliminate the absorbed water on the sample surface. The chemical compositions of the synthesized bridgmanite could not be measured by EPMA because of small grain size less than submicron. Therefore the chemical compositions were estimated from the result of the XRD pattern by subtracting the amount of the other phases. The estimated chemical compositions of Tschermak substitution bridgmanites were consistent with the

  3. Burden of rare variants in ALS genes influences survival in familial and sporadic ALS.

    Science.gov (United States)

    Pang, Shirley Yin-Yu; Hsu, Jacob Shujui; Teo, Kay-Cheong; Li, Yan; Kung, Michelle H W; Cheah, Kathryn S E; Chan, Danny; Cheung, Kenneth M C; Li, Miaoxin; Sham, Pak-Chung; Ho, Shu-Leong

    2017-10-01

    Genetic variants are implicated in the development of amyotrophic lateral sclerosis (ALS), but it is unclear whether the burden of rare variants in ALS genes has an effect on survival. We performed whole genome sequencing on 8 familial ALS (FALS) patients with superoxide dismutase 1 (SOD1) mutation and whole exome sequencing on 46 sporadic ALS (SALS) patients living in Hong Kong and found that 67% had at least 1 rare variant in the exons of 40 ALS genes; 22% had 2 or more. Patients with 2 or more rare variants had lower probability of survival than patients with 0 or 1 variant (p = 0.001). After adjusting for other factors, each additional rare variant increased the risk of respiratory failure or death by 60% (p = 0.0098). The presence of the rare variant was associated with the risk of ALS (Odds ratio 1.91, 95% confidence interval 1.03-3.61, p = 0.03), and ALS patients had higher rare variant burden than controls (MB, p = 0.004). Our findings support an oligogenic basis with the burden of rare variants affecting the development and survival of ALS. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Factores que afectan a la estructura de los recubrimientos de cinc obtenidos por inmersión

    Directory of Open Access Journals (Sweden)

    Seré, P. R.

    1997-12-01

    Full Text Available Coating solidification during hot-dip galvanizing is a very complex process due to Al-Fe, Al-Fe-Zn and Fe-Zn intermetallic compounds development. Fe-Zn intermetallic are brittle and detrimental for the coating ductility, while the diffusion towards the surface of a segregated insoluble alloying such as antimonium causes the sheet darkness. Steel sheets of different roughness were hot-dip galvanized under different operation conditions using a laboratory scale simulator. The effect of steel roughness and process parameters upon coating characteristics were analyzed. Experimental results showed that the steel roughness affects the coating thickness, zinc grain size and texture as well as the out-bursts development, while the process parameters affects the Fe2Al5 morphology and antimonium segregation.

    En el proceso de galvanizado por inmersión, la solidificación del recubrimiento constituye una etapa compleja en la que, además de formarse compuestos intermetálicos de Al-Fe, Al-Fe-Zn y Fe-Zn, tiene lugar la segregación de elementos aleantes insolubles como el antimonio. Ambos fenómenos son, al menos parcialmente, indeseables ya que la fragilidad de los intermetálicos de Fe-Zn afecta a la ductilidad del recubrimiento y la difusión del antimonio hacia la superficie causa su ennegrecimiento. Con un simulador diseñado a escala de laboratorio se galvanizaron chapas de diferente rugosidad sujetas a condiciones operativas también diferentes, analizándose el efecto de la rugosidad del acero y de los parámetros del proceso sobre las características del recubrimiento. Los resultados obtenidos demostraron que la rugosidad afecta tanto al espesor del recubrimiento, tamaño de grano y textura del cinc como a la formación de out-bursts, mientras que los parámetros del proceso lo hacen sobre la morfología del intermetálico Fe2Al5 y la segregación de antimonio.

  5. Influence of Al grain boundaries segregations and La-doping on embrittlement of intermetallic NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Kovalev, Anatoly I., E-mail: a_kovalev@sprg.ru; Wainstein, Dmitry L.; Rashkovskiy, Alexander Yu.

    2015-11-01

    Highlights: • We investigated Al grain boundaries segregations in ordered pure and La-doped NiAl. • Structural segregation of Al decreases critical strain for brittle cracks nucleation. • La alloying sharply improves plasticity of NiAl intermetallic. • Metallicity of interatomic bonds on grain boundaries increases at La alloying. • We have experimentally measured by EELFS that La atoms are located in Al sublattice. - Abstract: The microscopic nature of intergranular fracture of NiAl was experimentally investigated by the set of electron spectroscopy techniques. The paper demonstrates that embrittlement of NiAl intermetallic compound is caused by ordering of atomic structure that leads to formation of structural aluminum segregations at grain boundaries (GB). Such segregations contain high number of brittle covalent interatomic bonds. The alloying by La increases the ductility of material avoiding Al GB enrichment and disordering GB atomic structure. The influence of La alloying on NiAl mechanical properties was investigated. GB chemical composition, atomic and electronic structure transformations after La doping were investigated by AES, XPS and EELFS techniques. To qualify the interatomic bonds metallicity the Fermi level (E{sub F}) position and electrons density (n{sub eff}) in conduction band were determined in both undoped and doped NiAl. Basing on experimental results the physical model of GB brittleness formation was proposed.

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

    KAUST Repository

    Wang, Junsheng; Horsfield, Andrew; Lee, Peter D.; Brommer, Peter

    2010-01-01

    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.

  7. 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.

  8. Strength of Al and Al-Mg/alumina bonds prepared using ultrahigh vacuum diffusion bonding

    International Nuclear Information System (INIS)

    King, W.E.; Campbell, G.H.; Wien, W.L.; Stoner, S.L.

    1994-01-01

    The authors have measured the cross-breaking strength of Al and Al-Mg alloys bonded with alumina. Diffusion bonding of Al and Al-Mg alloys requires significantly more bonding time than previously thought to obtain complete bonding. In contrast to previous diffusion bonding studies, fracture morphologies are similar to those obtained in bonds formed by liquid phase reaction; i.e., bonds are as strong or stronger than the ceramic; and fracture tends to propagate in the metal for pure Al and near the interface in the ceramic for the alloys. There are indications that the fracture morphology depends on Mg content and therefore on plasticity in the metal

  9. Política, ethos social e identidad en la cuba contemporánea Politics, social ethos and identity in contemporary Cuba

    Directory of Open Access Journals (Sweden)

    Luis RONIGER

    2010-07-01

    Full Text Available La persistencia del modelo político cubano es paradójica al analizarla sobre e! transfondo de extrema penuria económica, pérdida de apoyo internacional y presiones en aumento de parte de los Estados Unidos y la oposición anticastrista fuera de Cuba. No obstante las circunstancias internacionales adversas que debió enfrentar Cuba tras la caída de la Unión Soviética -su principal fuente de apoyo económico- el gobierno revolucionario logró mantenerse en e! poder. Los autores analizan las condiciones que posibilitaron la proyección del compromiso revolucionario, las medidas económicas y los mecanismos políticos adoptados en la última década a fin de adaptarse a la cambiante situación global al tiempo que mantuvieron la estabilidad interna, pese a los serios desafíos internacionales y las presiones internas. Se sugiere que un factor clave en la persistencia del modelo deriva de su conexión con las identidades colectivas y el ethos social de la nación cubana en el período postrevolucionario. Este factor instrumental en asegurar la continuidad de! modelo cubano, ha limitado empero su proyección actual en las otras naciones latinoamericanas, a pesar de los alcances destacados en ámbitos de desarrollo humano, como son la salud y la educación.The resilience of the Cuban political model appears paradoxical against the backdrop of extreme economic hardship, loss o foreign support and increasing pressure by the United States and the anti-Castro opposition. Notwithstanding adverse global circumstances following the demise of the Soviet Union -its main source of economic support- the Cuban revolutionary government has managed to hold onto power. In this paper the authors analyze the conditions under which Cuba has remained committee to its revolutionary path and the economic measures and political mechanisms it has adopted to maintain internal stability, despite serious international challenges and internal pressures. They suggest that

  10. Wear protection in cutting tool applications by PACVD (Ti,Al)N and Al2O3 coatings

    International Nuclear Information System (INIS)

    Kathrein, M.; Heiss, M.; Rofner, R.; Schleinkofer, U.; Schintlmeister, W.; Schatte, J.; Mitterer, C.

    2001-01-01

    Various (Ti,Al)N-, Al 2 O 3 -, and (Ti,Al)N/Al 2 O 3 multilayer coatings were deposited onto cemented carbide cutting tool inserts by a plasma assisted chemical vapor deposition (PACVD) technique. Al 2 O 3 coatings were deposited using the gaseous mixture AlCl 3 , Ar, H 2 , and O 2 . (Ti,Al)N intermediate layers were deposited in the same device using the process mentioned and the gases AICl 3 , Ar, H 2 , TiCl 4 and N 2 . The unique properties of (Ti,Al)N/Al 2 O 3 multilayer coatings result in superior wear protection for cutting inserts applied in severe multifunction cutting processes. The influence of different deposition temperatures an structure and properties of the coatings like crystallographic phases, chemical composition, mechanical and technological properties is shown. PACVD (Ti,Al)N/Al 2 O 3 coated cutting inserts with fine grained crystalline α/κ-Al 2 O 3 offer performance advantages which are superior with respect to coatings deposited by chemical vapor deposition (CVD) due to the low deposition temperature applied. (author)

  11. Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

    Science.gov (United States)

    Pandit, Bhishma; Seo, Tae Hoon; Ryu, Beo Deul; Cho, Jaehee

    2016-06-01

    The current transport mechanism of graphene formed on AlxGa1-xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40) is investigated. The current-voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

  12. Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

    Directory of Open Access Journals (Sweden)

    Bhishma Pandit

    2016-06-01

    Full Text Available The current transport mechanism of graphene formed on AlxGa1−xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40 is investigated. The current–voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

  13. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    International Nuclear Information System (INIS)

    Wolf, W.; Bolfarini, C.; Kiminami, C.S.; Botta, W.J.

    2016-01-01

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al 71 Co 13 Fe 8 Cr 8 , Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al 71 Co 13 Fe 8 Cr 8 alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al 71 Co 13 Fe 8 Cr 8 . The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al 5 Co 2 and Al 13 Co 4 and are quasicrystalline approximants. Although the Al 5 Co 2 phase has already been reported in the Al 71 Co 13 Fe 8 Cr 8 alloy, the presence of the monoclinic Al 13 Co 4 is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al 13 Co 4 phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al 71 Co 13 Fe 8 Cr 8 alloy, the compositions Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were chosen to be within the region of formation of the quaternary extension of the Al 13 Co 4 phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system, around the compositions studied, is composed of quaternary extensions of Al-Co intermetallic phases, which present solubility of Fe and Cr at Co atomic sites. - Highlights: •The Al rich region of the Al

  14. Comparison of ALS functionality and plant growth in ALS-inhibitor susceptible and resistant Myosoton aquaticum L.

    Science.gov (United States)

    Liu, Weitang; Bai, Shuang; Jia, Sisi; Guo, Wenlei; Zhang, Lele; Li, Wei; Wang, Jinxin

    2017-10-01

    Herbicide target-site resistance mutations may cause pleiotropic effects on plant ecology and physiology. The effect of several known (Pro197Ser, Pro197Leu Pro197Ala, and Pro197Glu) target-site resistance mutations of the ALS gene on both ALS functionality and plant vegetative growth of weed Myosoton aquaticum L. (water chickweed) have been investigated here. The enzyme kinetics of ALS from four purified water chickweed populations that each homozygous for the specific target-site resistance-endowing mutations were characterized and the effect of these mutations on plant growth was assessed via relative growth rate (RGR) analysis. Plants homozygous for Pro197Ser and Pro197Leu exhibited higher extractable ALS activity than susceptible (S) plants, while all ALS mutations with no negative change in ALS kinetics. The Pro197Leu mutation increased ALS sensitivity to isoleucine and valine, and Pro197Glu mutation slightly increased ALS sensitivity to isoleucine. RGR results indicated that none of these ALS resistance mutations impose negative pleiotropic effects on relative growth rate. However, resistant (R) seeds had a lowed germination rate than S seeds. This study provides baseline information on ALS functionality and plant growth characteristics associated with ALS inhibitor resistance-endowing mutations in water chickweed. Copyright © 2017. Published by Elsevier Inc.

  15. AL FIKR AL BALAGHI FI AL MA’ĂNI ‘INDA AS SAKĂKI FI KITABIHI MIFTAHUL ULUM DIRĂSAH BALAGHIYYAH

    Directory of Open Access Journals (Sweden)

    Talqis Nurdianto

    2018-02-01

    Full Text Available Miftāhul ‘Ulūm, written by al-Sakākī, especially the third part, was the beginning of a new phase in the development of Arabic rhetoric. Al-Sakākī divided the rhetoric into three fields of study, which are  (1 Ma’ānī, (2 Bayān, (3 Badī’. However, his style is influenced by philosophers, theologians and their verbal lexicon, which are difficult to take, especially for the ordinary recipient. Al-Sakākī described that his book containing several types of literature, namely, ‘ilm ṣarf in complete version and its conclusion, derivation science, and the grammatical study in the completeness of Ma’ānī and Bayān. The meaning of Makna is the study of completeness and conclusion. Therefore, books and prose, and poem require al-‘Arūḍ and al-Qawāfī include Ṣarf, Grammar, Ma’ānī, Bayān, limitation, reasoning, al’Arūḍ, and al-Qawāfī. He argued that the fields of study were influential in delivering knowledge to the student in order to reach the goal of the author towards his book.This research was an analytical descriptive study of al-Sakākī rhetoric that focused on the normative aspect represented by rhetorical rule and aesthetic aspects. Those aspects were shown by the feeling. Al-Sakākī rhetoric thought is a method based on mental division and has conducted in the construction of many factors, which the most important of them are philosophy and logic. Keywords: thought, rhetoric, meanings, sakkaki, study

  16. A study on wear resistance and microcrack of the Ti3Al/TiAl + TiC ceramic layer deposited by laser cladding on Ti-6Al-4V alloy

    International Nuclear Information System (INIS)

    Li Jianing; Chen Chuanzhong; Squartini, Tiziano; He Qingshan

    2010-01-01

    Laser cladding of the Al + TiC alloy powder on Ti-6Al-4V alloy can form the Ti 3 Al/TiAl + TiC ceramic layer. In this study, TiC particle-dispersed Ti 3 Al/TiAl matrix ceramic layer on the Ti-6Al-4V alloy by laser cladding has been researched by means of X-ray diffraction, scanning electron microscope, electron probe micro-analyzer, energy dispersive spectrometer. The main difference from the earlier reports is that Ti 3 Al/TiAl has been chosen as the matrix of the composite coating. The wear resistance of the Al + 30 wt.% TiC and the Al + 40 wt.% TiC cladding layer was approximately 2 times greater than that of the Ti-6Al-4V substrate due to the reinforcement of the Ti 3 Al/TiAl + TiC hard phases. However, when the TiC mass percent was above 40 wt.%, the thermal stress value was greater than the materials yield strength limit in the ceramic layer, the microcrack was present and its wear resistance decreased.

  17. Study of the 27Al(n,2,)26Al reaction via accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Wallner, A.

    2000-06-01

    The excitation function for the 27 Al(n,2n) 26 Al reaction is expected to show a strongly non-linear behavior in the neutron-energy region around 14 MeV, the neutron energy in D-T plasmas; thus the production rate of 26 Al (t 1/2 =7.2*10 5 a) in D-T fusion environments can in principle be used to measure the temperature of such plasmas. Existing measurements, however, are strongly discordant. Therefore, a new accurate measurement of the 27 Al(n,2n) 26 Al cross sections in the near threshold region (E n =13.5-14.8 MeV) was performed with the goal to achieve relative cross sections with the highest accuracy possible. In addition, the measurements were also designed to provide good absolute cross-section values, as absolute cross sections are important for radioactive waste predictions. Samples of Al metal were irradiated with neutrons in the energy range near threshold (E th =13.55 MeV) at the Radiuminstitutes of both Vienna and St. Petersburg, and in Tokai-mura, Japan. In Tuebingen irradiations with neutrons of higher energies (17 and 19 MeV) were performed. The amount of 26 Al produced during the irradiations was measured via accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA). This work represents the first 26 Al measurements for this new facility. With this system, a background as low as 3*10 -15 for 26 Al/ 27 Al isotope ratios was obtained, corresponding to a (n,2n) cross section of 0.04 mb. Utilizing AMS, cross sections with much higher precision and considerably closer to the threshold than in previous investigations could be measured. The prerequisite for its application as a temperature monitor, namely a very well known shape of the excitation function was met. A quantitative prediction of the sensitivity of this method for monitoring the temperature in a D-T fusion plasma was therefore possible. For thermal plasmas temperature changes in the order of 5 to 15 % should be detectable. An even higher sensitivity was found

  18. Magnetostrictive properties of FeAl/polyester and FeAl/silicone composites

    Energy Technology Data Exchange (ETDEWEB)

    Riesgo, G. [Dpto. de Ciencias y Técnicas de la Navegación, Universidad de Oviedo, Campus universitario de Gijón, 33203 Gijón (Spain); Carrizo, J. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Elbaile, L., E-mail: elbaile@uniovi.es [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Crespo, R.D. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Sepúlveda, R. [Dpto. de Ingeniería Mecánica y de los Materiales, Universidad de Sevilla, Isla Cartuja, 41092 Sevilla (Spain); García, J.A. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2017-01-15

    Highlights: • Nanocrystalline powders of FeAl have been obtained from the Fe{sub 81}Al{sub 19} ribbon produced by melt spinning. • The method allows the obtainment of a FeAl solid solution from the starting process. • The microstructure and magnetic properties of the powders were investigated. • Composites with a magnetostriction of 45 ppm have been obtained. - Abstract: Ribbons of composition Fe{sub 81}Al{sub 19} obtained by the melt spinning method have been used to yield powder by mechanical milling. Using this method, a rapid nanocrystallization and a FeAl solid solution phase was obtained from the start of the process. The microstructural and magnetic properties as well as the XRD patterns of the powders were studied in function of the milling time. Grain refinement and an increase of the coercive field were the main transformations resulting from increasing the milling time. Two sets of magnetostrictive composites were produced from the 100 h-milled powder. In one of them polyester was used as matrix and in the other one silicone. In the case of the silicone composites cured in a magnetic field of 140 mT in the longitudinal direction a saturation magnetostriction as high as 45 ppm was obtained.

  19. Thermodynamic calculation of Al-Gd and Al-Gd-Mg phase equilibria checked by key experiments

    International Nuclear Information System (INIS)

    Groebner, J.; Kevorkov, D.; Schmid-Fetzer, R.

    2001-01-01

    The binary Al-Gd and the ternary Al-Gd-Mg systems were calculated using the Calphad method. It is demonstrated that previous interpretation of ternary liquidus temperatures below 700 C must be related to other phase equilibria. The actual ternary liquidus temperatures are much higher, up to some 600 C above the previous interpretation in literature. They are widely governed by the high-melting compounds Al 2 Gd and Al 3 Gd with liquidus surfaces stretching far into the ternary system. A small number of key experiments in this work confirmed the calculated liquidus temperature and the phase relations. The available experimental data in literature fit excellently with the calculation in the binary Al-Gd system. In the ternary Al-Gd-Mg system, which is shown in several sections of the phase diagram, a good agreement can be observed too, considering the necessary reinterpretation of the liquidus temperatures suggested by Rokhlin et al. Ternary solubilities were not found experimentally. The ternary compound Al 4 GdMg (τ) forms in a ternary peritectic reaction at 761 C. (orig.)

  20. Forged HITEMAL: Al-based MMCs strengthened with nanometric thick Al{sub 2}O{sub 3} skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Balog, Martin, E-mail: ummsbama@savba.sk [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Krizik, Peter; Nosko, Martin; Hajovska, Zuzana [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Victoria Castro Riglos, Maria [Centro Atómico Bariloche, Av. Bustillo 9.500, 8400 Bariloche, Río Negro (Argentina); Rajner, Walter [New Materials Development GmbH, Römerstrasse 28, 83410 Laufen, Leobendorf (Germany); Liu, De-Shin [National Chung Cheng University, 168 University Rd., Min-Hsiung, 62102 Chia-Yi, Taiwan (China); Simancik, Frantisek [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia)

    2014-09-08

    Bulk Al–Al{sub 2}O{sub 3} metal matrix composites (MMCs) named HITEMAL (high temperature aluminum) were fabricated in situ by forging compaction of five different types of gas-atomized commercial purity Al powders with a mean particle size in the range of 1–9 µm. As-forged HITEMAL consisted of (sub)micrometric Al grains (matrix) decorated with nanometric thick amorphous Al{sub 2}O{sub 3} (a-Al{sub 2}O{sub 3}) skeleton. Low-angle grain boundaries (LAGBs) free of Al{sub 2}O{sub 3} were located in the Al grain interior. The Al grain size and the portion of LAGBs increased with the increase in the relative powder surface area. As-forged HITEMAL shows excellent thermal stability up to 400 °C for 24 h. Annealing at temperatures ≥450 °C led to crystallization and morphological transformation from a-Al{sub 2}O{sub 3} skeleton to nanometric γ-Al{sub 2}O{sub 3} particles. Owing to the pinning effect of Al{sub 2}O{sub 3} phase, no Al grain growth took place during annealing up to 500 °C. HITEMAL showed attractive mechanical properties especially when tested at 300 °C (yield strength up to 220 MPa, Young's modulus up to 58 GPa). Despite the presence of a nearly continuous a-Al{sub 2}O{sub 3} skeleton along adjacent Al grains, forged HITEMAL materials had reasonable room temperature elongation of 7–26%. HITEMAL's elongation decreased as the Al grain size decreased and with increased testing temperature. The loss in elongation (uniform and total) was attributed to the inhomogeneous flow, which occurred due to high densities of high angle grain boundaries (dislocation sinks) and small content of LAGBs. The strength of HITEMAL stemmed from grain boundary mediated strengthening mechanisms. The results showed a positive deviation from the Hall–Petch plot, which is typical behavior of ultrafine-grained metals. Transformation of a-Al{sub 2}O{sub 3} skeleton to γ-Al{sub 2}O{sub 3} particles led to deterioration of the HITEMAL strength and Young's modulus.

  1. Determination of Al concentration in Al doped ZnO using Auger spectra excited by Mo X-rays

    International Nuclear Information System (INIS)

    Toth, J.; Koever, L.; Cserny, I.; Varga, D.

    2006-01-01

    Complete text of publication follows. A good conductor with excellent transparency is of crucial importance for the window layer of CIGS solar cells. Al doped ZnO is a good candidate for this purpose, its conductivity depends on the concentration and chemical state of the Al dopant atoms. It was demonstrated that the non-conventional XPS using Mo X-rays for excitation is a very sensitive tool for the detection of Al, P, Si [1, 2, 3]. The present paper compares the experimental ratios for Zn/Al photoinduced peak intensity ratios obtained using both Al and Mo X-ray excitations. The Mo excited Zn/Al intensity ratios can be determined with higher selectivity and sensitivity than the Zn/Al intensity ratios excited by Al X-rays. The experiments were performed with a hemispherical deflector electron spectrometer [4]. The chemical state of the Al was identified to be close to that in Al 2 O 3 . The atomic concentrations were determined using a calibration curve based on ZnO/Al samples with known composition of Al. The energy dependent efficiency of the electron spectrometer was determined comparing REELS spectra of Cu specimen to standard spectra measured by K. Goto (Nagoya Institute of Technology, Japan). For evaluation of the Al atomic concentrations from the measured photoelectron intensities the photoionisation cross-sections of Band et al [5] and the IMFP data of S. Tanuma et al [6] and C.J. Powell and A. Jablonski [7] were used. (author)

  2. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    Science.gov (United States)

    Wang, Xiao; Wang, Wei; Wang, Jingli; Wu, Hao; Liu, Chang

    2017-03-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgGa δ doped AlGaN SLs. Mg acceptor activation energy was significantly reduced from 0.378 to 0.331 eV by using MgGa δ doping in SLs instead of traditional doping in alloys. This new process was confirmed to be able to realize high p-type doping in high Al-content AlGaN.

  3. Al-Shebab: An Al-Qaeda Affiliate Case Study (2Rev)

    Science.gov (United States)

    2017-10-01

    deputies responsible for finance , administration, and security. Coordination among regional groups is common.10 The deputy leader of al-Shebab, Mukhtar...Maaliya (Ministry of Finance ) controlled taxation. A complex court system also emerged. Multiple training camps were built that focused on hand-to-hand...Nathan Chandler, Counterterrorism and Counterinsurgency in Somalia: Assessing the Campaign Against Al Shabaab, Rand Corporation , 2016, accessed 6/5

  4. Swellable packers in fracturing and stimulation

    Directory of Open Access Journals (Sweden)

    Jorge Ordóñez

    2017-12-01

    Full Text Available En el presente trabajo se presenta la idea del uso de swellable packers como herramienta adicional, enfocado principalmente en el uso alternativo de cemento. Los swellable packers contienen elastómeros que absorben cierto tipo de fluido, existiendo dos grandes grupos que son: elastómeros con tendencia a fluido con base agua y elastómeros con tendencia a fluido con base aceite. Estos packers fueron creados con el objetivo de usarse como aisladores de zonas, ya que son packers que gracias a sus elastómeros se hinchan al contacto con el fluido al que son a fin, logrando un sello completo en diferentes zonas. Con el pasar de los años se los enfocó en usos diferentes para el que netamente fueron creados, usos como: estimulación de pozos, incluyendo fracturamientos (resistencia a altas presiones, completacion de pozos, trabajos de cementación, etc.  Luego del análisis de varios casos y de presentar las ventajas del uso de esta herramienta se propone el empleo de los swellable packers en reemplazo del cemento, esto ayudará a reducir costos de operaciones, tiempo de rig y NPTs.

  5. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    OpenAIRE

    Xiao Wang; Wei Wang; Jingli Wang; Hao Wu; Chang Liu

    2017-01-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgG...

  6. Tadris Al Mufradat Li Tathbiq Maharah Al Kalam Fi Madrasah Al Muallimin Al Islamiyyah Li Mahad Bait Al Arqam Balong Jember

    Directory of Open Access Journals (Sweden)

    Muhammad Ardy Zaini

    2017-06-01

    Full Text Available There are four  skills in teaching Arabic. Ie listening, speaking, reading, and writing. Among these four, speaking considered one of the most important objectives of learning foreign language. In order to speak properly, one must know the vocabulary and apply it in a sentence. The aims of this research is to describe the teaching of vocabulary to apply the speaking skill in the school of Islamic teachers in the Institute of Bait al Arqom Balong Jember. This study used qualitative approach. The data collection was taken trough observation, personal interview, history and documentation. The teaching of vocabulary to apply the speaking skill at the Islamic Teachers' School at the Institute of Bait Al Arqam Balong Jember has gone well in terms of planning (general objectives and specific objectives, implementation (materials, use of the teaching method and teaching aids, and evaluation (assessment and evaluation. This teaching is to apply the speaking skill in terms of conversation or dialogue and lecture.

  7. NEK1 genetic variability in a Belgian cohort of ALS and ALS-FTD patients.

    Science.gov (United States)

    Nguyen, Hung Phuoc; Van Mossevelde, Sara; Dillen, Lubina; De Bleecker, Jan L; Moisse, Matthieu; Van Damme, Philip; Van Broeckhoven, Christine; van der Zee, Julie

    2018-01-01

    We evaluated the genetic impact of the amyotrophic lateral sclerosis (ALS) risk gene never in mitosis gene a-related kinase 1 (NEK1) in a Belgian cohort of 278 patients with ALS (n = 245) or ALS with frontotemporal dementia (ALS-FTD, n = 33) and 609 control individuals. We identified 2 ALS patients carrying a loss-of-function (LOF) mutation, p.Leu854Tyrfs*2 and p.Tyr871Valfs*17, that was absent in the control group. A third LOF variant p.Ser1036* was present in 2 sibs with familial ALS but also in an unrelated control person. Missense variants were common in both patients (3.6%) and controls (3.0%). The missense variant, p.Arg261His, which was previously associated with ALS risk, was detected with a minor allele frequency of 0.90% in patients compared to 0.33% in controls. Taken together, NEK1 LOF variants accounted for 1.1% of patients, although interpretation of pathogenicity and penetrance is complicated by the observation of occasional LOF variants in unaffected individuals (0.16%). Furthermore, enrichment of additional ALS gene mutations was observed in NEK1 carriers, suggestive of a "second hit" model were NEK1 variants may modify disease presentation of driving mutations. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. The effect of ammonia flow in the AlN spacer on the electrical properties of InAlN/AlN/GaN HEMT structures

    International Nuclear Information System (INIS)

    Gamarra, Piero; Lacam, Cedric; Magis, Michelle; Tordjman, Maurice; Di Forte Poisson, Marie-Antoinette

    2012-01-01

    During the past few years it has been reported that a thin AlN spacer of few nanometers needs to be inserted in InAlN/GaN high electron mobility transistors (HEMTs) to obtain high 2DEG carrier mobility. This work presents a systematic study of the effects of varying the ammonia flow in the AlN spacer of InAlN/AlN/GaN HEMTs grown by low pressure metalorganic vapour phase epitaxy (LP-MOVPE). The strain state, the surface roughness and the growth rate of AlN were found to be dependent on the V/III ratio. In addition the ammonia flow in the interlayer has a strong impact on the structural properties of the subsequent InAlN barrier layer and on the electrical properties of the structure. A sheet resistance as low as 327 Ω/□ with a sheet carrier density of 1.5 x 10 13 cm -2 has been obtained at room temperature. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. The effect of ammonia flow in the AlN spacer on the electrical properties of InAlN/AlN/GaN HEMT structures

    Energy Technology Data Exchange (ETDEWEB)

    Gamarra, Piero; Lacam, Cedric; Magis, Michelle; Tordjman, Maurice; Di Forte Poisson, Marie-Antoinette [III-V Lab., Marcussis (France)

    2012-01-15

    During the past few years it has been reported that a thin AlN spacer of few nanometers needs to be inserted in InAlN/GaN high electron mobility transistors (HEMTs) to obtain high 2DEG carrier mobility. This work presents a systematic study of the effects of varying the ammonia flow in the AlN spacer of InAlN/AlN/GaN HEMTs grown by low pressure metalorganic vapour phase epitaxy (LP-MOVPE). The strain state, the surface roughness and the growth rate of AlN were found to be dependent on the V/III ratio. In addition the ammonia flow in the interlayer has a strong impact on the structural properties of the subsequent InAlN barrier layer and on the electrical properties of the structure.istance as low as 327 {omega}/{open_square} with a sheet carrier density of 1.5 x 10{sup 13} cm{sup -2} has been obtained at room temperature. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, W., E-mail: witorw@gmail.com [Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Bolfarini, C., E-mail: cbolfa@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Kiminami, C.S., E-mail: kiminami@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Botta, W.J., E-mail: wjbotta@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil)

    2016-12-15

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}, Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}. The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al{sub 5}Co{sub 2} and Al{sub 13}Co{sub 4} and are quasicrystalline approximants. Although the Al{sub 5}Co{sub 2} phase has already been reported in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the presence of the monoclinic Al{sub 13}Co{sub 4} is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al{sub 13}Co{sub 4} phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the compositions Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were chosen to be within the region of formation of the quaternary extension of the Al{sub 13}Co{sub 4} phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system

  11. Corrosion analysis of AlMg2 and AlMgSi using electrochemical method

    International Nuclear Information System (INIS)

    Dian A; Maman Kartaman; Rosika K; Yanlinastuti

    2014-01-01

    Corrosion test of cladding materials and structures of research reactor fuel, AlMgSi and AlMg2 have been performed in demineralized water of pH 2 and 6.7 using an electrochemical method. Corrosion phenomenon is affected by several factor such as composition and condition of solution. The purpose of this activity is to investigate the corrosion phenomena through the determination of the parameters of corrosion and polarization curve. The materials used are AlMg2 and AlMgSi alloy in circular dish shape with an area of 1 Cm"2. Preparation of the test sample is performed through several stages polishing, cleaning and drying procedures followed ASTM G3. The electrochemical method is done by measuring the open circuit potential (OCP), polarization resistance and potentiodynamic in demineralized water of pH 2 and pH 6.7 at temperature of 25°C. The results of the OCP is the corrosion potential (Ecorr) of AlMg2 and AlMgSi each of -906.1 mV and -619.8 mV at pH 2 and -868.6 and -756.7 mV at pH 6.7 mV. The results of measurements by polarization resistance technique showed that the corrosion rate of AlMg2 and AlMgSi in safe category (<2 mpy) at pH 6.7 and at pH 2 corrosion rate increased significantly, but still in the lightweight category (<20 mpy). Potentiodynamic curves showed that the passivation at pH 6.7 is very low while the passivation at pH 2 occurs within a relatively short range potential and followed events corroded. (author)

  12. Probabilistic fracture mechanics in the integrity evaluation of components; Mecanica de fractura probabilista en la evaluacion de la integridad de componentes

    Energy Technology Data Exchange (ETDEWEB)

    Franco Nava, Jose Manuel; Torres Toledano, Jose Gerardo; Sanchez Sanchez, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    Because of the importance of fracture mechanics in applications to pressure vessels, piping and other components used in thermal power plants, the Mechanical Engineering Unit of the Instituto de Investigaciones Electricas (IIE) has been developing activities in this field since some years ago. In this paper, the process for the analysis of probabilistic fracture mechanics is described. As an example, an application to the calculation of fault probability in piping systems, is presented. [Espanol] Dada la importancia de la mecanica de fractura en aplicaciones de recipientes a presion, tuberias y otros componentes utilizados en centrales termicas, la Unidad de Ingenieria Mecanica del Instituto de Investigaciones Electricas (IIE) ha venido desarrollando actividades en este campo desde hace algunos anos. En el presente trabajo, se describe el proceso para el analisis de mecanica de fractura probabilista. Como ejemplo se presenta una aplicacion al calculo de probabilidad de falla en tuberias.

  13. Probabilistic fracture mechanics in the integrity evaluation of components; Mecanica de fractura probabilista en la evaluacion de la integridad de componentes

    Energy Technology Data Exchange (ETDEWEB)

    Franco Nava, Jose Manuel; Torres Toledano, Jose Gerardo; Sanchez Sanchez, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    Because of the importance of fracture mechanics in applications to pressure vessels, piping and other components used in thermal power plants, the Mechanical Engineering Unit of the Instituto de Investigaciones Electricas (IIE) has been developing activities in this field since some years ago. In this paper, the process for the analysis of probabilistic fracture mechanics is described. As an example, an application to the calculation of fault probability in piping systems, is presented. [Espanol] Dada la importancia de la mecanica de fractura en aplicaciones de recipientes a presion, tuberias y otros componentes utilizados en centrales termicas, la Unidad de Ingenieria Mecanica del Instituto de Investigaciones Electricas (IIE) ha venido desarrollando actividades en este campo desde hace algunos anos. En el presente trabajo, se describe el proceso para el analisis de mecanica de fractura probabilista. Como ejemplo se presenta una aplicacion al calculo de probabilidad de falla en tuberias.

  14. Desenvolvimento de um ambiente de aprendizagem para o ensino de controle de processos

    Directory of Open Access Journals (Sweden)

    André Pereira da Costa

    2014-12-01

    Full Text Available Esta pesquisa teve como objetivo construir um ambiente de aprendizagem para o ensino de Controle deProcessos, tornando-se um importante recurso didático que favorece o aprendizado dos graduandos do CursoSuperior de Tecnologia em Automação Industrial, no IFPB Campus Cajazeiras. Então, em nosso percursometodológico, utilizamos o software MATLAB, bem como sua linguagem de programação característica, paratornar viável a construção do ambiente. Tal software é bastante utilizado na área de Controle de Processos emdiversas pesquisas, contribuindo tanto para o desenvolvimento prático, pois possibilita que novos métodos decontrole sejam avaliados e empregados nas mais distintas situações, como também no campo educacional.Além disso, utilizamos os pêndulos simples e invertido como modelos mecânicos do simulador. Dentre osresultados obtidos, podemos mencionar a simplicidade de utilização e manipulação do ambiente, pois suainterface gráfica facilita a execução das simulações, de modo dinâmico, na qual o estudante de graduaçãopoderá configurar o sistema e o controlador, além de visualizar o resultado da simulação em um gráfico.

  15. Catalytic effect of Al and AlN interlayer on the growth and properties of containing carbon films

    International Nuclear Information System (INIS)

    Zhou, Bing; Liu, Zhubo; Tang, Bin; Rogachev, A.V.

    2015-01-01

    Highlights: • DLC and CN x bilayers with Al (AlN) interlayer were fabricated by cathode arc technique. • Complete diffusion of Al and C atoms occurs at the interface of Al/DLC (CN x ) bilayer. • Al/CN x bilayer presents a higher content of Csp 3 /Csp 2 bonds. • The hardness of Al/DLC bilayer decreases but increases for the other bilayers. • Morphology of the bilayers was explained by growth mechanism of DLC and surface state of substrate. - Abstract: Diamond-like carbon (DLC) and carbon nitride (CN x ) bilayer films with Al and AlN interlayer were fabricated by pulse cathode arc technique. The structure, composition, morphology and mechanical properties of the films were investigated by Raman, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Knoop sclerometer and surface profilometer. The results indicated that the complete diffusion between C and Al atoms occurs in the Al/DLC and Al/CN x bilayer. Al interlayer induces the increase of the size and ordering of Csp 2 clusters in the films but AlN interlayer increases the disordering degree of Csp 2 clusters. XPS results showed that a higher content of Csp 3 /Csp 2 bonds presents in the Al/CN x bilayer, and Al and AlN interlayer decreases the atomic ratio of N/C. AFM with phase contrast mode illustrated the morphologic characteristics of the bilayer films. All the bilayers show a nano-structural surface. The morphology changes of the bilayer were well explained by the surface state of the substrate and the growth mechanism of DLC films. The hardness of Al/DLC bilayer decreases but it increases for the other bilayers compared to the corresponding DLC (CN x ) monolayer. The internal stress of the bilayer is significantly lower than that of the monolayer except for the AlN/CN x bilayer. These studies could make the difference at the time of choosing a suitable functional film for certain application

  16. Characteristics in AlN/AlGaN/GaN Multilayer-Structured High-Electron-Mobility Transistors

    International Nuclear Information System (INIS)

    Gui-Zhou, Hu; Ling, Yang; Li-Yuan, Yang; Si, Quan; Shou-Gao, Jiang; Ji-Gang, Ma; Xiao-Hua, Ma; Yue, Hao

    2010-01-01

    A new multilayer-structured AlN/AlGaN/GaN heterostructure high-electron-mobility transistor (HEMT) is demonstrated. The AlN/AlGaN/GaN HEMT exhibits the maximum drain current density of 800 mA/mm and the maximum extrinsic transconductance of 170 mS/mm. Due to the increase of the distance between the gate and the two-dimensional electron-gas channel, the threshold voltage shifts slightly to the negative. The reduced drain current collapse and higher breakdown voltage are observed on this AlN/AlGaN/GaN HEMT. The current gain cut-off frequency and the maximum frequency of oscillation are 18.5 GHz and 29.0 GHz, respectively. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  17. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    International Nuclear Information System (INIS)

    Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

    2013-01-01

    The testing techniques and experimental methods of the 60 Co 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. (authors)

  18. Cu-segregation at the Q'/α-Al interface in Al-Mg-Si-Cu alloy

    International Nuclear Information System (INIS)

    Matsuda, Kenji; Teguri, Daisuke; Uetani, Yasuhiro; Sato, Tatsuo; Ikeno, Susumu

    2002-01-01

    Cu segregation was detected at the Q ' /α-Al interface in an Al-Mg-Si-Cu alloy by energy-filtered transmission electron microscopy. By contrast, in a Cu-free Al-Mg-Si alloy no segregation was observed at the interface between the matrix and Type-C precipitate

  19. Aplicación del modelo polinomial en la evaluación de la uniformidad de riego del aspersor autocompensado Nelson R10

    Directory of Open Access Journals (Sweden)

    Fanny del Rocío Rodríguez-Jarama

    2015-01-01

    Full Text Available Los métodos de evaluación de la uniformidad de riego estiman las condiciones hidráulicas de funcionamiento del sistema de riego y su influencia en la aplicación de láminas de agua, con base en las necesidades hídricas de un cultivo. El modelo de evaluación utilizado en la presente investigación fue el polinomial. El ensayo evaluó el funcionamiento del sistema de riego con 4 presiones de operación distintas, medidas a la salida de la válvula del módulo de riego, y por cada presión de operación se tomaron 16 datos de caudales, en 5 módulos de riego instalado con el aspersor autocompensado Nelson R10. Como resultado se obtuvo el coeficiente de uniformidad, el coeficiente de distribución, el área adecuadamente irrigada y el factor de adecuación del riego. Uno de los principales resultados fue la no existencia de diferencia significativa entre las presiones mientras esta se mantengan en el rango de autocompensación; por otro lado, en el coeficiente de distribución sí existen diferencias significativas entre los tratamientos, a pesar de que todos dan valores mayores al 90%, en contraste con los porcentajes del área relativa adecuadamente regada, que no superan el 50% en ninguno de los tratamientos. Con lo anterior se pudo validar y verificar que el aspersor Nelson R10 autocompensado, una vez instalado en campo, cumple con las características técnicas de operación expuestas en el catálogo del fabricante, sin embargo, sí se debe manejar y controlar la lámina de riego aplicada.

  20. Effect of Al-5Ti-0.62C-0.2Ce Master Alloy on the Microstructure and Tensile Properties of Commercial Pure Al and Hypoeutectic Al-8Si Alloy

    Directory of Open Access Journals (Sweden)

    Wanwu Ding

    2017-06-01

    Full Text Available Al-5Ti-0.62C-0.2Ce master alloy was synthesized by a method of thermal explosion reaction in pure molten aluminum and used to modify commercial pure Al and hypoeutectic Al-8Si alloy. The microstructure and tensile properties of commercial pure Al and hypoeutectic Al-8Si alloy with different additions of Al-5Ti-0.62C-0.2Ce master alloy were investigated. The results show that the Al-5Ti-0.62C-0.2Ce alloy was composed of α-Al, granular TiC, lump-like TiAl3 and block-like Ti2Al20Ce. Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min can significantly refine macro grains of commercial pure Al into tiny equiaxed grains. The Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 30 min still has a good refinement effect. The tensile strength and elongation of commercial pure Al modified by the Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min increased by roughly 19.26% and 61.83%, respectively. Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min can significantly refine both α-Al grains and eutectic Si of hypoeutectic Al-8Si alloy. The dendritic α-Al grains were significantly refined to tiny equiaxed grains. The morphology of the eutectic Si crystals was significantly refined from coarse needle-shape or lath-shape to short rod-like or grain-like eutectic Si. The tensile strength and elongation of hypoeutectic Al-8Si alloy modified by the Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min increased by roughly 20.53% and 50%, respectively. The change in mechanical properties corresponds to evolution of the microstructure.

  1. Tailoring ultrafine grained and dispersion-strengthened Ti2AlC/TiAl ...

    Indian Academy of Sciences (India)

    and Ti-Al pre-alloyed powders at low temperature of 1150◦C. The composite mainly consisted ... Metal–matrix composites; mechanical properties; microstructures; sintering. 1. Introduction γ-TiAl-based intermetallic alloys have been extensively.

  2. Stagnation of the exploitation of Al ores and the depression of world prices of Al

    Directory of Open Access Journals (Sweden)

    Slavkovský Jozef

    1999-03-01

    Full Text Available In the contribution, data on Al – a metal of the 20th century are compiled together with the problems of genesis of the Al mineral raw ma-terials as well as types of bauxite and Al-laterite deposits. Furthermore, an overview of the world exploitation of bauxite during 1935-1980 is given along with the prognoses to 2000 and present situation (1992-1996. Overviews of the production of Al follows, providing its rela-tion to the bauxite exploitation. Contrary to the prognoses, a stabilization or stagnation has been observed in the exploitation of bauxite and production of Al during nineties, which a tendency is directly reflected in the world price of this commodity. When analyzing the Al prices for a longer period, some serious deviations can be noticed, that however presently represent a long-term minimum. We hope the stagnation of the production and the price decline are only temporary and new possibilities of the utilization of Al will be found soon.

  3. A study on preparation and hydriding of β-Mg2Al3 and γ-Mg17Al12

    International Nuclear Information System (INIS)

    Hadi Suwarno

    2009-01-01

    The mechanism of the synthetic formation of β-Mg 2 Al 3 and γ-Mg 17 Al 12 has been studied. Mechanical alloying of Mg and Al powders with the atomic ratio of Mg:Al = 2:3 in toluene solution yields β-Mg 2 Al 3 compound after milling for 30 h. The γ-Mg 17 Al 12 can be formed by heating the β-Mg 2 Al 3 at 430°C under high vacuum. The measured hydrogen capacities of β-Mg 2 Al 3 and γ-Mg 17 Al 12 as hydride at 300°C are 3.2 and 4.9 wt%, respectively. Microstructure of the Mg-Al specimen shows that on hydriding at 300°C the polygonal shape of the γ-Mg 17 Al 12 changes into irregular shapes which are composed of γ-MgH 2 and Al. (author)

  4. Marinbiologisk optegnelse i NUḪBAT AL-DAHR FĪ ʿAǦ ʾIB AL-BARR WA-AL-BAḤR

    OpenAIRE

    Provencal, Philippe

    2014-01-01

    I det arabiske geografiske værk NUḪBAT AL-DAHR FĪ ʿAǦ ʾIB AL-BARR WA-AL-BAḤR (færdigskrevet mellem 1324 og 1327) fra omtales seks dyr fra Adenbugten. Det dreje sig om savrokke, kuglefisk, pilrokke, pindsvinefisk og hvalhaj. Det sidste dyr har ikke kunnet bestemmes. Artiklen bringer en oversættelse af optegnelsen til engelsk samt både en filologisk som en biologisk kommentar. The aim of this article is to present a medieval Arabic report regarding sixanimals from the Gulf of Aden, to provid...

  5. 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

  6. Adhesive and tribocorrosive behavior of TiAlPtN/TiAlN/TiAl multilayers sputtered coatings over CoCrMo

    Science.gov (United States)

    Canto, C. E.; Andrade, E.; Rocha, M. F.; Alemón, B.; Flores, M.

    2017-09-01

    The tribocorrosion resistance and adherence of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by PVD reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt in order to enhance the tribocorrosion resistance of a biomedical alloy of CoCrMo. Tribocorrosion tests were performed using Simulated Body Fluid (SBF) at typical body temperature with a tribometer in a pin on disk test. The elemental composition and thickness of the coating which behave better at the tribocorrosion tests were evaluated by means of RBS (Rutherford Backscattering Spectroscopy) IBA (Ion Beam Analysis) technique, using an alpha particles beam of 1.8 MeV, before and after the reciprocating motion in the tribocorrosion test. In order to simulate the elemental profile of the samples, the SIMNRA simulation computer code was used. Measurements of the adhesion of the coatings to the substrate were carried on by means of a scratch test using a tribometer. By taking micrographs of the produced tracks, the critical loads at which the coatings are fully separated from the substrate were determined. From these tests it was observed that a coating with 10 min of TiAlPtN in a TiAlPtN/TiAl period of 30 min in multilayers of 10 periods and with an average thickness of 145 nm for the TiAlPtN nanolayers had the best tribocorrosion resistance behavior, compared to that of the CoCrMo alloy. The RBS experiments showed a reduction of the thickness of the films along with some loss of the multilayer structure after the reciprocating motion. The adhesion tests indicated that the multilayer with the average TiAlPtN thickness of 145 nm displayed the highest critical load. These results indicate a high correlation between the adherence and the tribocorrosion behavior.

  7. Microstructure of Reaction Zone Formed During Diffusion Bonding of TiAl with Ni/Al Multilayer

    Science.gov (United States)

    Simões, Sónia; Viana, Filomena; Koçak, Mustafa; Ramos, A. Sofia; Vieira, M. Teresa; Vieira, Manuel F.

    2012-05-01

    In this article, the characterization of the interfacial structure of diffusion bonding a TiAl alloy is presented. The joining surfaces were modified by Ni/Al reactive multilayer deposition as an alternative approach to conventional diffusion bonding. TiAl substrates were coated with alternated Ni and Al nanolayers. The nanolayers were deposited by dc magnetron sputtering with 14 nm of period (bilayer thickness). Joining experiments were performed at 900 °C for 30 and 60 min with a pressure of 5 MPa. Cross sections of the joints were prepared for characterization of their interfaces by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), high resolution TEM (HRTEM), energy dispersive x-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). Several intermetallic compounds form at the interface, assuring the bonding of the TiAl. The interface can be divided into three distinct zones: zone 1 exhibits elongated nanograins, very small equiaxed grains are observed in zone 2, while zone 3 has larger equiaxed grains. EBSD analysis reveals that zone 1 corresponds to the intermetallic Al2NiTi and AlNiTi, and zones 2 and 3 to NiAl.

  8. Al-quran dalam Perspektif Budaya

    OpenAIRE

    Sudrajat, Ajat

    2009-01-01

    Al-Quran merupakan kitab suci terakhir yang diturunkan kepada manusia. Tujuan utama diturunkannya al-Quran adalah sebagai kitab petunjuk yang meliputi bidang akidah, syariah, dan akhlak. Akan tetapi di luar ketiga petunjuk tersebut, al-Quran telah memberikan motivasi dan inspirasi kepada umat Islam dalam berbagai bidang kehidupan sehingga melahirkan jenis budaya tertentu. Dialog intelektual yang dilakukan secara kreatif oleh umat Islam terhadap al-Quran ternyata telah menghasilkan lahirnya ge...

  9. ITIJAHAT KAUN AL-NABI WA AL-RASUL FI SYAKHSIYAH MUHAMMAD FI NATSR MAULID AL-BARZANJI

    Directory of Open Access Journals (Sweden)

    Himmah Istomah

    2017-08-01

    Full Text Available One of human personalities is humanist. Based on the understanding of Maslow’s theory of motivation, researcher seeks to uncover kinds of motivational needs of Muhammad Saw contained in Maulid Al-Barzanjiy (the work of Ja 'far bin Hasan al-Barzanji (d. 1763 M. The goal is realized through a descriptive qualitative approach with  text analysis  about Psycholiterature of Endraswara. The results of this study indicate that in Maulid Al-Barzanji there are Muhammad Saw’s five needs and how their satisfying perfectly,  namely: physiological needs, safety, social, esteem, and self-actualization. Thus, it can be interpreted that Muhammad SAW as an ordinary human having motivational needs. His prophetic and apostleship honor is not a direct blessing from Allah, but he had been through some complicated processes in life. This can be applied by his followers, so they can complete their motivational needs to reach the satiation as a caliph and to be useful person in this world.

  10. Microstructure and bonding mechanism of Al/Ti bonded joint using Al-10Si-1Mg filler metal

    International Nuclear Information System (INIS)

    Sohn, Woong H.; Bong, Ha H.; Hong, Soon H.

    2003-01-01

    The microstructures and liquid state diffusion bonding mechanism of cp-Ti to 1050 Al using an Al-10.0wt.%Si-1.0wt.%Mg filler metal with 100 μm in thickness have been investigated at 620 deg. C under 1x10 -4 Torr. The effects of bonding process parameters on microstructure of bonded joint have been analyzed by using an optical microscope, AES, scanning electron microscopy and EDS. The interfacial bond strength of Al/Ti bonded joints was measured by the single lap shear test. The results show that the bonding at the interface between Al and filler metal proceeds by wetting the Al with molten filler metal, and followed by removal of oxide layer on surface of Al. The interface between Al and filler metal moved during the isothermal solidification of filler metal by the diffusion of Si from filler metal into Al layer. The interface between Al and filler metal became curved in shape with increasing bonding time due to capillary force at grain boundaries. The bonding at the interface between Ti and filler metal proceeds by the formation of two different intermetallic compound layers, identified as Al 5 Si 12 Ti 7 and Al 12 Si 3 Ti 5 , followed by the growth of the intermetallic compound layers. The interfacial bond strength at Al/Ti joint increased with increasing bonding time up to 25 min at 620 deg. C. However, the interfacial bond strength of Al/Ti joint decreased after bonding time of 25 min at 620 deg. C due to formation of cavities in Al near Al/intermetallic interfaces

  11. Micromechanisms of fracture and fatigue in Ti3Al based and TiAl based intermetallics

    International Nuclear Information System (INIS)

    James, A.W.; Chave, R.A.; Hippsley, C.A.; Bowen, P.

    1993-01-01

    Micromechanisms of fracture and fatigue crack growth resistance in specific Ti 3 Al based and TiAl based intermetallics are reviewed. Effects of test temperature, environment and microstructure on crack growth resistance are considered in detail for several Ti 3 Al and Ti'Al based intermetallic systems under development. The implications of these studies for the structural reliability of these materials is also addressed briefly. (orig.)

  12. Core electron binding energy shifts of AlBr3 and Al2Br6 vapor

    International Nuclear Information System (INIS)

    Mueller, Astrid M.; Plenge, Juergen; Leone, Stephen R.; Canton, Sophie E.; Rude, Bruce S.; Bozek, John D.

    2006-01-01

    The Al 2p and Br 3d inner-shell photoelectron spectra of aluminum tribromide monomer and dimer vapor were measured at 90 and 95 eV photon energy, respectively, to determine the core electron binding energies of the atoms in the two molecular species. While AlBr 3 has three identical Br atoms, Al 2 Br 6 exhibits four terminal and two bridging Br atoms. The species are identified by their distinct valence photoelectron spectra. Comparison of the observed Al 2p 1/2 and Al 2p 3/2 electron binding energies of AlBr 3 with those of Al 2 Br 6 shows that there is a chemical shift of (0.15 ± 0.03) eV to lower energy in the dimer. In Al 2 Br 6 , an assignment is proposed in which the Br 3d 3/2 and Br 3d 5/2 binding energies of terminal Br atoms are (1.18 ± 0.03) eV lower than those of bridging Br atoms. This assignment assumes that both types of Br atoms have similar cross-sections for ionization. With this result, the Br 3d 3/2 and Br 3d 5/2 binding energies of Br atoms in AlBr 3 are (0.81 ± 0.03) eV lower than those of bridging Br atoms of the dimer but (0.37 ± 0.03) eV higher than those of terminal Br atoms of the dimer. The obtained chemical shifts are considered in terms of the binding relations and electron density distributions in both molecules. Chemical shifts that are larger than a few hundred millielectron volts, as observed in the Al 2 Br 6 /AlBr 3 system, offer potential to study the dissociation dynamics of the dimer in a femtosecond visible or ultraviolet-pump/XUV-probe experiment

  13. PENDEKATAN HERMENEUTIK DALAM PEMAHAMAN HADIS (Kajian Kitab Fath al-Bari Karya Ibn Hajar Al-‘Asqalani

    Directory of Open Access Journals (Sweden)

    Agusni Yahya

    2014-12-01

    Full Text Available The hadith explanation book of Sahih al-Bukhari written by Ibn Hajar Al-‘Asqalani, Fath al-Bari, is one of the most pupular books in Moslem ummah. Is widely used by Moslem scholars to meet the meanings of hadiths compiled by the imam al-Bukhari in his Sahih al-Bukhari. Fath al-Bari is considered significant to do the research on it in order to develop the science of hadith, mainly through the hermeneutic method. By using this method, the research questions are: 1. How does Ibn Hajar Al-‘Asqalani explain the matans (hadith texts of Sahih al Bukhari in connection with hermeneutic method? 2. What are the hermeneutic principles used by Ibn Hajar Al-‘Asqalani in his explanations of hadith? This research is expected to respond the research questions above so that it can be implimented the field of hadith in relation to develop hadith methodology. Finally, the research uncover that in his explanations of hadiths,  Ibn Hajar Al-‘Asqalani is oriented his world views to the classical Islam, the era of Prophet’s companions and their successors, the Salaf al-Salih. He does not express the Islamic world issues available in his time in his explanations of the hadiths. He is considered a normative ‘ulama since he is not influenced by the emerging cases situated his time in Egypt, Mecca and Madina. He tends to be textual to explain the matans of hadiths although to some extent he uncovers the historical contexts of the hadiths he explains. This is common for a muhadith  whose main jobs is to collect and narrate the whole data on Prophet's sayings, acts and permissions either on sanads (narrators or matans (texts.Keywords:  Fath al-Bari; sharh al-hadith; hermeneutik.

  14. Thermophysical properties of αAl2O3, MgAl2O4 and AlN at low tempertures

    International Nuclear Information System (INIS)

    Burghartz, S.

    1995-12-01

    A possibility for producing energy in future might be the nuclear fusion. The process of nuclear fusion is characterized by melting nuclei of hydrogen atoms (deuterium and tritium) which yield to the production of helium atom nuclei. For this process extremely high temperatures of the deuterium-tritium-gas plasma are necessary. The additional heating of the plasma by microwaves requires materials with low diaelectric losses and high thermal conductivity. The thermal conductivity can be increased by cooling the windows which lead to the plasma chambre. Experimental investigations with the aim to check the influence of liquid nitrogen (T=70 K) on the cooling of the windows were performed in the temperature region 70 K 2 O 3 , MgAl 2 O 4 and AlN were measured. The thermal conductivity can be calculated using the equation λ=αc p ρ λ=thermal conductivity α=thermal diffusivity c p =specific heat (at constant pressure) ρ=density. Furthermore a theoretical method to calculate the thermal conductivity at low temperatures is presented; this is done by using a model modification of heat transport in electric insulators. As result the influence of intrinsic parameters (crystal structure, interatomar binding, anharmonicity) and extrinsic parameters (point defects, dislocations, boundary areas) upon thermal conductivity of α-Al 2 O 3 , MgAl 2 O 4 and AlN are achieved. (orig.)

  15. Grain refinement of Al wrought alloys with newly developed AlTiC master alloys; Kornfeinung von Al-Knetlegierungen mit neu entwickelten AlTiC-Vorlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, W. [Vereinigte Aluminium-Werke AG, Bonn (Germany). Forschung und Entwicklung

    2000-10-01

    AlTiC master alloys are a new grain refiner type to produce an equiaxed grain structure of cast extrusion and rolling ingots. These master alloys contain Ti carbides which act as nucleants of the {alpha} solid solution during solidification. The TiC content is lower than the TiB{sub 2} content of the industrial proved AlTiB master alloys. Benefits of the AlTiC master alloys are the low agglomeration tendency of the Ti carbides in the melt and that no Zr poisoning takes place. Despite of the low Ti carbide content the grain refinement performance can be very efficient, if low melt temperatures during casting will be used and as result of this a sufficient constitutional supercooling at the solidification front is achieved. (orig.)

  16. Advanced life support (ALS) instructors experience of ALS education in Western Australia: a qualitative exploratory research study.

    Science.gov (United States)

    Taplin, John; McConigley, Ruth

    2015-04-01

    When cardiac arrest occurs, timely competent advanced life support (ALS) interventions by nursing staff can influence patient outcomes. Ongoing ALS education influences maintenance of competency and avoids skill decay. To explore the methods of ALS education delivery for nurses in the workplace; describe the issues relating to maintaining ALS competency; explore ALS competency decay for nurses and develop recommendations for the provision of continuing ALS education. A qualitative exploratory design was used to study ALS education provision in the workplace. Data were collected from ALS nurse experts in Western Australia by face-to-face and phone interviews. Semi-structured interviews were conducted and organised around a set of predetermined questions. Two major themes were identified; the first theme Demand and Supply describes the increasing demand for ALS education for nurses and the challenges with providing timely cost effective traditional face-to-face ALS education. The second theme, Choosing The Best Education Options describes new ways to provide ALS education using emerging technologies. The study suggested that using e-learning methods would assist with educating the maximum amount of nurses in a timely manner and e-learning and teleconferencing offer opportunities to reach nurses in distant locations. Delivering ALS education more frequently than annually would increase skills maintenance and lessen skill decay. Further research is required to explore which blended e-learning model is best suited to ALS education. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Al-Qaeda-Syria (AQS): An Al-Qaeda Affiliate Case Study

    Science.gov (United States)

    2017-10-01

    Special Operations/Low Intensity Conflict CT Counterterrorism FF Foreign Fighter FSA Free Syrian Army GEC Global Engagement Center HTS Hay’at...war as an opportunity for the global jihadist movement, an opportunity that paralleled the one Iraq had offered a decade earlier.11 He was initially...Zawahiri’s vision of Al-Qaeda franchises oriented toward winning popular support. When al-Zawahiri published his “General Guidelines for Jihad” in

  18. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    International Nuclear Information System (INIS)

    Qu, Jun; He, Xiaoman; Chen, Min; Hu, Huimin; Zhang, Qiwu; Liu, Xinzhong

    2017-01-01

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu_2(OH)_2CO_3) and aluminum hydroxide (Al(OH)_3) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  19. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun, E-mail: forsjun@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); He, Xiaoman; Chen, Min; Hu, Huimin [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Zhang, Qiwu, E-mail: zhangqw@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Liu, Xinzhong [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118 China (China)

    2017-04-15

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu{sub 2}(OH){sub 2}CO{sub 3}) and aluminum hydroxide (Al(OH){sub 3}) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  20. Superstructure formation in PrNi_2Al_3 and ErPd_2Al_3

    International Nuclear Information System (INIS)

    Eustermann, Fabian; Hoffmann, Rolf-Dieter; Janka, Oliver; Oldenburg Univ.

    2017-01-01

    The intermetallic phase ErPd_2Al_3 was obtained by arc-melting of the elements and subsequent annealing for crystal growth. The sample was studied by X-ray diffraction on powders and single crystals. The structure of ErPd_2Al_3 was refined from X-ray diffraction data and revealed a superstructure of PrNi_2Al_3 - a CaCu_5 derivative (P6/m, a=1414.3(1), c=418.87(3) pm wR=0.0820, 1060 F"2 values, 48 variables). The same superstructure was subsequently found for PrNi_2Al_3 (P6/m, a=1407.87(4), c=406.19(2) pm, wR=0.0499, 904 F"2 values, 47 variables). In the crystal structure, the aluminium and transition metal atoms form a polyanionic network according to [T_2Al_3]"δ"-, while rare earth atoms fill cavities within the networks. They are coordinated by six transition metal and twelve aluminum atoms. In contrast to the PrNi_2Al_3 type structure reported so far, two crystallographic independent rare-earth sites are found of which one (1b) is shifted by 1/2 z, causing a distortion in the structure along with a recoloring of the T and Al atoms in the network.

  1. Derecho humano al agua y al saneamiento: derechos estrechamente vinculados al derecho a la vida

    OpenAIRE

    Fernández Aller, Maria Celia; Luis Romero, Elena de; Guzmán Acha, Cristina

    2013-01-01

    Los derechos humanos al agua y al saneamiento están íntimamente relacionados con otros derechos esenciales para la vida, como la alimentación o la salud. Su reconocimiento como derechos humanos en 2010 marca un hito importante en el respeto, protección y realización de estos derechos, que se encuentran seriamente vulnerados para una mayoría de población más vulnerable y empobrecida, sobre todo en el ámbito rural. Mucho camino queda aún para conseguir no sólo la disponibilidad de agua y saneam...

  2. Deformation mechanisms of nanotwinned Al

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinghang [Texas A & M Univ., College Station, TX (United States)

    2016-11-10

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  3. Deformation mechanisms of nanotwinned Al

    International Nuclear Information System (INIS)

    Zhang, Xinghang

    2016-01-01

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  4. Study on Microstructure and Mechanical Properties of Hypereutectic Al-18Si Alloy Modified with Al-3B.

    Science.gov (United States)

    Gong, Chunjie; Tu, Hao; Wu, Changjun; Wang, Jianhua; Su, Xuping

    2018-03-20

    An hypereutectic Al-18Si alloy was modified via an Al-3B master alloy. The effect of the added Al-3B and the modification temperature on the microstructure, tensile fracture morphologies, and mechanical properties of the alloy were investigated using an optical microscope, Image-Pro Plus 6.0, a scanning electron microscope, and a universal testing machine. The results show that the size of the primary Si and its fraction decreased at first, and then increased as an additional amount of Al-3B was added. When the added Al-3B reached 0.2 wt %, the fraction of the primary Si in the Al-18Si alloy decreased with an increase in temperature. Compared with the unmodified Al-18Si alloy, the tensile strength and elongation of the alloy modified at 850 °C with 0.2 wt % Al-3B increased by 25% and 81%, respectively. The tensile fracture of the modified Al-18Si alloy exhibited partial ductile fracture characteristics, but there were more areas with ductile characteristics compared with that of the unmodified Al-18Si alloy.

  5. 26Mg(p,n)26Al and 23Na(α,n)26Al reactions

    International Nuclear Information System (INIS)

    Skelton, R.T.

    1985-01-01

    Cross sections for the 26 Mg(p,n) 26 Al reaction were measured from threshold at 4.988 MeV to 5.820 MeV. Cross sections for the 23 Na(α,n) 26 Al reaction were measured from threshold at 3.483 MeV to 4.597 MeV. In each case, separate measurements were to the ground state and to the first and second excited states of 26 Al. Cross sections for the inverse reactions were calculated and reaction rate factors relating to the destruction of 26 Al in a supernova environment were determined. Astrophysical implications relating to the observation of live and extinct 26 Al are discussed. Excitation functions for several additional exit channels for the 26 Mg + rho and 23 Na + α reactions are reported

  6. effect of the parameters of AlN/GaN/AlGaN and AlN/GaN/InAlN heterostructures with a two-dimensional electron gas on their electrical properties and the characteristics of transistors on their basis

    Energy Technology Data Exchange (ETDEWEB)

    Tsatsulnikov, A. F., E-mail: andrew@beam.ioffe.ru [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation); Lundin, V. W.; Zavarin, E. E.; Yagovkina, M. A.; Sakharov, A. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation); Usov, S. O. [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation); Zemlyakov, V. E.; Egorkin, V. I. [National Research University of Electronic Technology (MIET) (Russian Federation); Bulashevich, K. A.; Karpov, S. Yu. [“Soft-Impact” Ltd. (Russian Federation); Ustinov, V. M. [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation)

    2016-10-15

    The effect of the layer thickness and composition in AlGaN/AlN/GaN and InAlN/AlN/GaN transistor heterostructures with a two-dimensional electron gas on their electrical and the static parameters of test transistors fabricated from such heterostructures are experimentally and theoretically studied. It is shown that the use of an InAlN barrier layer instead of AlGaN results in a more than twofold increase in the carrier concentration in the channel, which leads to a corresponding increase in the saturation current. In situ dielectric-coating deposition on the InAlN/AlN/GaN heterostructure surface during growth process allows an increase in the maximum saturation current and breakdown voltages while retaining high transconductance.

  7. Fabrication and thermal characterization of amorphous and nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti compound

    Energy Technology Data Exchange (ETDEWEB)

    Tavoosi, Majid, E-mail: ma.tavoosi@gmail.com

    2017-01-15

    In this study, the fabrication and structural characterization of amorphous/nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti phase has been performed. In this regards, milling and annealing processes were applied on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} (at. %) powder mixture for different periods of time. The prepared samples were characterized using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM) and differential scanning calorimetery (DSC). According to the results, supersaturated solid solution, nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti (with average crystallite size of about 7 nm) and amorphous phases indicated three different microstructures which can be formed in Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} system during milling process. The formed supersaturated solid solution and amorphous phases were unstable and transformed to Al{sub 9}FeNi/Al{sub 3}Ti intermetallic compound during annealing process. It is shown that, Al{sub 9}FeNi phase in Al{sub 9}FeNi/Al{sub 3}Ti intermetallic compound can decompose into Al{sub 3}Ni, Al{sub 13}Fe{sub 4} and liquid phases during a reversible peritectic reaction at 809 °C. - Highlights: • We study the effect of milling process on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} alloy. • We study the effect of annealing on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} supersaturated solid solution phase. • We study the effect of annealing on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} amorphous phase. • We study the thermal behaviour of Al{sub 9}FeNi/Al{sub 3}Ti compound.

  8. Computer aided cooling curve analysis for Al-5Si and Al-11Si alloys ...

    African Journals Online (AJOL)

    The effect of grain refiner, modifier, and combination of grain refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both grain refiner and modifier.

  9. 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...

  10. Gd3+-ESR and magnetic susceptibility of GdCu4Al8 and GdMn4Al8

    International Nuclear Information System (INIS)

    Coldea, R.; Coldea, M.; Pop, I.

    1994-01-01

    Gd ESR of GdCu 4 Al 8 and GdMn 4 Al 8 and magnetic susceptibility of GdCu 4 Al 8 , GdMn 4 Al 8 , and YMn 4 Al 8 were measured in the temperature range of 290K--460K and 90K--1050K, respectively. The occurrence of the Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 is strongly correlated with the critical value of d∼2.6 angstrom of the Mn-Mn distance below which the Mn moment is not stable. The experimental data for GdMn 4 Al 8 , compared with the data for the isostructural compounds GdCu 4 Al 8 and YMn 4 Al 8 , show that near the critical value of d, the existence of Mn moment depends not only on the value of d, but also on the local magnetic surroundings. It has been revealed that the magnetic character of Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 changes from an itinerant electron type to a local-moment type with increasing temperature

  11. Effect of AlB2-Mg interaction on the mechanical properties of Al-based composites

    International Nuclear Information System (INIS)

    Calderon, Hermes E.; Hidalgo, Ruth G.I.; Melgarejo, Z. Humberto; Suarez, O. Marcelo

    2010-01-01

    A series of Al-based composites with a matrix containing 2.5 wt.%Cu and 1 wt.%Mg, and reinforced with Al diborides was manufactured and characterized via microscopy and mechanical testing. The impact resistance of the composites revealed interaction between AlB 2 dispersoids and Mg originally present in the Al matrix. An unexpected increase in the absorbed impact energy of composites with diborides prompted complementary experiments leading to this finding. Hardness tests were correlated to those results and provided further evidence of the interaction between Mg and the dispersoids. Additional energy dispersive spectroscopy (EDS) analysis and X-ray diffraction tests supported with crystal modeling demonstrated that Mg effectively diffused into the AlB 2 crystal producing a doped structure with an Al 1-x Mg x B 2 formula where x lies between 0.08 and 0.15.

  12. Potential skin involvement in ALS: revisiting Charcot's observation - a review of skin abnormalities in ALS.

    Science.gov (United States)

    Paré, Bastien; Gros-Louis, François

    2017-07-26

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons of the brain and spinal cord, leading to progressive paralysis and death. Interestingly, many skin changes have been reported in ALS patients, but never as yet fully explained. These observations could be due to the common embryonic origin of the skin and neural tissue known as the ectodermal germ layer. Following the first observation in ALS patients' skin by Dr Charcot in the 19th century, in the absence of bedsores unlike other bedridden patients, other morphological and molecular changes have been observed. Thus, the skin could be of interest in the study of ALS and other neurodegenerative diseases. This review summarizes skin changes reported in the literature over the years and discusses about a novel in vitro ALS tissue-engineered skin model, derived from patients, for the study of ALS.

  13. Effects of O in a binary-phase TiAl-Ti3Al alloy: from site occupancy to interfacial energetics

    International Nuclear Information System (INIS)

    Wei Ye; Xu Huibin; Zhou Hongbo; Zhang Ying; Lu Guanghong

    2011-01-01

    We have investigated site occupancy and interfacial energetics of a TiAl-Ti 3 Al binary-phase system with O using a first-principles method. Oxygen is shown to energetically occupy the Ti-rich octahedral interstitial site, because O prefers to bond with Ti rather than Al. The occupancy tendency of O in TiAl alloy from high to low is α 2 -Ti 3 Al to the γ-α 2 interface and γ-TiAl. We demonstrate that O can largely affect the mechanical properties of the TiAl-Ti 3 Al system. Oxygen at the TiAl-Ti 3 Al interface reduces both the cleavage energy and the interface energy, and thus weakens the interface strength but strongly stabilizes the TiAl/Ti 3 Al interface with the O 2 molecule as a reference. Consequently, the mechanical property variation of TiAl alloy due to the presence of O not only depends on the number of TiAl/Ti 3 Al interfaces but also is related to the O concentration in the alloy.

  14. A study on wear resistance and microcrack of the Ti{sub 3}Al/TiAl + TiC ceramic layer deposited by laser cladding on Ti-6Al-4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li Jianing, E-mail: ljnljn1022@163.com [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China); Chen Chuanzhong [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China); Squartini, Tiziano [INFM-Department of Physics, Siena University, Siena 53100 (Italy); He Qingshan [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China)

    2010-12-15

    Laser cladding of the Al + TiC alloy powder on Ti-6Al-4V alloy can form the Ti{sub 3}Al/TiAl + TiC ceramic layer. In this study, TiC particle-dispersed Ti{sub 3}Al/TiAl matrix ceramic layer on the Ti-6Al-4V alloy by laser cladding has been researched by means of X-ray diffraction, scanning electron microscope, electron probe micro-analyzer, energy dispersive spectrometer. The main difference from the earlier reports is that Ti{sub 3}Al/TiAl has been chosen as the matrix of the composite coating. The wear resistance of the Al + 30 wt.% TiC and the Al + 40 wt.% TiC cladding layer was approximately 2 times greater than that of the Ti-6Al-4V substrate due to the reinforcement of the Ti{sub 3}Al/TiAl + TiC hard phases. However, when the TiC mass percent was above 40 wt.%, the thermal stress value was greater than the materials yield strength limit in the ceramic layer, the microcrack was present and its wear resistance decreased.

  15. Synthesis behavior of nanocrystalline Al-Al2O3 composite during low time mechanical milling process

    International Nuclear Information System (INIS)

    Alizadeh, Mostafa; Aliabadi, Morteza Mirzaei

    2011-01-01

    Research highlights: → In the low time milling the effect of Al 2 O 3 amount is investigated → Al 2 O 3 particles are distributed uniformly in the Al matrix → In the low time milling it is possible to produce nanostructured composite powder → Median size and bulk density measurements demonstrate reaching the steady state. - Abstract: In this work, four different volume fractions of Al 2 O 3 (10, 20, 30 and 40 vol.%) were mixed with the fine Al powder and the powder blends were milled for 5 h. Scanning electron microscopy analysis, particle size analysis and bulk density measurements were used to investigate the morphological changes and achieving the steady state conditions. The results showed that increasing the Al 2 O 3 content can provide the steady state particle size in 5 h milling process. It was found that increasing the volume fraction of Al 2 O 3 leads to increasing the uniformity of Al 2 O 3 . Standard deviations of microhardness measurements confirmed this result. The XRD pattern and XRF investigations depicted that increasing the Al 2 O 3 content causes an increase in the crystal defects, micro-strain and Fe contamination during 5 h milling process of nanocrystalline composite powders while the grain size is decreased. To investigate the effect of milling time, Al-30 vol.% Al 2 O 3 (which achieved steady state during 5 h milling process) was milled for 1-4 h. The results depicted that the milling time lower than 5 h, do not achieve to steady state conditions.

  16. Study of the ternary alloy systems Al-Ni-Fe and Al-Cu-Ru with special regard to quasicrystalline phases

    International Nuclear Information System (INIS)

    Lemmerz, U.

    1996-07-01

    Two ternary alloy-systems, the Al-Ni-Fe system and the Al-Cu-Ru system were studied with special regard to quasicrystalline phases. Isothermal sections were established in both systems in the stoichiometric area of the quasicrystalline phase. In the Al-Ni-Fe system a new stable decagonal phase was found. Its stoichiometric range is very small around Al 71.6 Ni 23.0 Fe 5.4 . The temperature range in which it is stable lies between 847 and 930 C. The decagonal phase undergoes a eutectoid reaction to the three crystalline phases Al 3 Ni 2 , Al 3 Ni and Al 13 Fe 4 at 847 C. It melts peritectically at 930 C forming Al 13 Fe 4 , Al 3 Ni 2 and a liquid. The investigations in the Al-Cu-Ru system concentrated on the phase equilibria between the icosahedral phase and its neighbouring phases in a temperature range between 600 and 1000 C. The icosahedral phase was observed in the whole temperature range. The investigated stoichiometric area extends down to Al contents of 45%, which allows the fields of existence to be determined for the ternary phases α-AlCuRu, the icosahedral phase and Al 7 Cu 2 Ru. Binary phases were determined down to the upper (high Al content) border of AlRu. No hitherto unknown phase was observed in the investigated area. Rietveld analyses were carried out on α-AlCuRu and Al 7 Cu 2 Ru showing some discrepancies from the α-AlMnSi structure taken as a base for α-AlCuRu and confirming the Al 7 Cu 2 Fe structure for Al 7 Cu 2 Ru. (orig.)

  17. Al-Cu-Li and Al-Mg-Li alloys: Phase composition, texture, and anisotropy of mechanical properties (Review)

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Knyazev, M. I.

    2016-04-01

    The results of studying the phase transformations, the texture formation, and the anisotropy of the mechanical properties in Al-Cu-Li and Al-Mg-Li alloys are generalized. A technique and equations are developed to calculate the amounts of the S1 (Al2MgLi), T1 (Al2CuLi), and δ' (Al3Li) phases. The fraction of the δ' phase in Al-Cu-Li alloys is shown to be significantly higher than in Al-Mg-Li alloys. Therefore, the role of the T1 phase in the hardening of Al-Cu-Li alloys is thought to be overestimated, especially in alloys with more than 1.5% Li. A new model is proposed to describe the hardening of Al-Cu-Li alloys upon aging, and the results obtained with this model agree well with the experimental data. A texture, which is analogous to that in aluminum alloys, is shown to form in sheets semiproducts made of Al-Cu-Li and Al-Mg-Li alloys. The more pronounced anisotropy of the properties of lithium-containing aluminum alloys is caused by a significant fraction of the ordered coherent δ' phase, the deformation mechanism in which differs radically from that in the solid solution.

  18. 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.

  19. Strain Balanced AlGaN/GaN/AlGaN nanomembrane HEMTs.

    Science.gov (United States)

    Chang, Tzu-Hsuan; Xiong, Kanglin; Park, Sung Hyun; Yuan, Ge; Ma, Zhenqiang; Han, Jung

    2017-07-25

    Single crystal semiconductor nanomembranes (NM) are important in various applications such as heterogeneous integration and flexible devices. This paper reports the fabrication of AlGaN/GaN NMs and NM high electron mobility transistors (HEMT). Electrochemical etching is used to slice off single-crystalline AlGaN/GaN layers while preserving their microstructural quality. A double heterostructure design with a symmetric strain profile is employed to ensure minimal residual strain in freestanding NMs after release. The mobility of the two-dimensional electron gas (2DEG), formed by the AlGaN/GaN heterostructure, is noticeably superior to previously reported values of many other NMs. AlGaN/GaN nanomembrane HEMTs are fabricated on SiO 2 and flexible polymeric substrates. Excellent electrical characteristics, including a high ON/OFF ratio and transconductance, suggest that III-Nitrides nanomembranes are capable of supporting high performance applications.

  20. Validated thermodynamic prediction of AlP and eutectic (Si) solidification sequence in Al-Si cast alloys

    International Nuclear Information System (INIS)

    Liang, S M; Schmid-Fetzer, R

    2016-01-01

    The eutectic microstructure in hypoeutectic Al-Si cast alloys is strongly influenced by AlP particles which are potent nuclei for the eutectic (Si) phase. The solidification sequence of AlP and (Si) phases is, thus, crucial for the nucleation of eutectic silicon with marked impact on its morphology. This study presents this interdependence between Si- and P-compositions, relevant for Al-Si cast alloys, on the solidification sequence of AlP and (Si). These data are predicted from a series of thermodynamic calculations. The predictions are based on a self-consistent thermodynamic description of the Al-Si-P ternary alloy system developed recently. They are validated by independent experimental studies on microstructure and undercooling in hypoeutectic Al-Si alloys. A constrained Scheil solidification simulation technique is applied to predict the undercooling under clean heterogeneous nucleation conditions, validated by dedicated experimental observations on entrained droplets. These specific undercooling values may be very large and their quantitative dependence on Si and P content of the Al alloy is presented. (paper)

  1. Phase diagrams of aluminium alloys of Al-Cu-Mg, Al-Mg-Si-Cu, and Al-Mg-Li system

    International Nuclear Information System (INIS)

    Ber, L.B.; Kaputkin, E.Ya.

    2001-01-01

    Isothermal diagrams of phase transformations (DPT) and temperature-time charts (TTC) of variation of electric conductivity and of mechanical features at tension were plotted following thermal treatment according to the pattern of direct hardening and ageing and according to the pattern of normal aging for D16 commercial alloy, Al-Cu-Mg model alloy of the same system, AD37 commercial alloys of Al-Mg-Si-Cu and 1424 one of Al-Li-Mg system. Phase transformations were studied by means of fluorescence electron microscopy, micro-X-ray spectral analysis, X-ray phase analysis of single crystals and polycrystals and differential scanning calorimetry. For every alloy comparison of TTC and DPT enables to clarity the mechanism of phase composition effect on features and to optimize conditions of hardening cooling and ageing [ru

  2. Superhydrophobic ZnAl double hydroxide nanostructures and ZnO films on Al and glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    De, Debasis, E-mail: debasis.de@bcrec.ac.in [Electronics and Instrumentation Engineering Department, Dr. B C Roy Engineering College, Durgapur, West Bengal 713206 (India); Sarkar, D.K. [Centre Universitaire de Recherche sur l' Aluminium (CURAL), L' Université du Québec à Chicoutimi, 555 Blvd. Université, Chicoutimi, Saguenay, Québec G7H 2B1 (Canada)

    2017-01-01

    Superhydrophobic nanostructured ZnAl: layered double hydroxides (LDHs) and ZnO films have been fabricated on Al and glass substrates, respectively, by a simple and cost effective chemical bath deposition technique. Randomly oriented hexagonal patterned of ZnAl: LDHs thin nanoplates are clearly observed on Al-substrate in the scanning electron microscopic images. The average size of these hexagonal plates is ∼4 μm side and ∼30 nm of thickness. While on the glass substrate, a oriented hexagonal patterned ZnO nanorods (height ∼5 μm and 1 μm diameter) are observed and each rod is further decorated throughout the top few nanometers with several nanosteps. At the top of the nanorod, a perfectly hexagonal patterned ZnO surface with ∼250 nm sides is observed. The tendency to form hexagonal morphological features is due to the hexagonal crystal structure of ZnO confirmed from X-ray diffraction patterns and transmission electron microscopy image. The ZnAl: LDHs and/or ZnO coated substrates have been passivated by using stearic acid (SA) molecules. Infrared spectra of passivated ZnAl: LDHs coated substrates confirm the presence of SA. X-ray diffraction pattern also corroborates the results of infrared spectrum. The contact angle of the as prepared samples is zero. The superhydrophobicity is achieved by observing contact angle of ∼161° with a hysteresis of ∼4° for Al-substrate. On the glass substrate, a higher contact angle of ∼168° with a lower hysteresis of ∼3° is observed. A lower surface roughness of ∼4.93 μm is measured on ZnAl: LDHs surface layer on the Al substrate as compare to a higher surface roughness of 6.87 μm measured on ZnO layer on glass substrate. The superhydrophobicity of passivated nanostructured films on two different substrates is observed due to high surface roughness and low surface energy. - Highlights: • ZnAl: layered double hydroxides (LDHs) nanoplates are fabricated on Al substrate. • ZnO nanorods are fabricated on

  3. Formation of Nb3Al in powder processed Nb-Al superconductors

    International Nuclear Information System (INIS)

    Johnson, P.E.

    1987-05-01

    In high magnetic fields, the critical current density is strongly dependent on the upper critical field, which is determined primarily by the stoichiometry of the Nb 3 Al. The critical temperature (T/sub c/), like the upper critical field, is considered to be a measure of the ''intrinsic'' quality of the superconductor, indicating the stoichiometry, order, and strain. If the A15 phase is stoichiometric and well ordered, a high T/sub c/ (and high H/sub C 2 /) is expected, regardless of the volume fraction of superconductor. On the other hand, if sigma phase is present with the A15, the resultant composition gradient across the sigma-A15 interface(s) requires that some of the A15 be off-stoichiometric, and therefore that the T/sub c/ (and H/sub C 2 /) be low. Thus the extent of the A15 (Nb 3 Al) reaction and the quality of the A15 formed are interdependent. This work focuses on the factors that control the extent of Nb 3 Al formation in Nb/Al powder wires. The morphology and content of the reacted and unreacted wires are studied in optical, SEM, and TEM micrographs. Critical current density data and its dependence on processing are explained in terms of the unreacted microstructure and its effect on the extent of Nb 3 Al formation. As a method of improving the critical current density, a new variation of the conventional powder process for wire manufacturing is developed and tested

  4. Al-Si/B{sub 4}C composite coatings on Al-Si substrate by plasma spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Sarikaya, Ozkan [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Anik, Selahaddin [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Aslanlar, Salim [Sakarya University, Faculty of Technical Education, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Cem Okumus, S. [Sakarya University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Celik, Erdal [Dokuz Eylul University, Engineering Faculty, Department of Metallurgical and Materials Engineering, Buca, Izmir 35160 (Turkey)]. E-mail: erdal.celik@deu.edu.tr

    2007-07-01

    Plasma-sprayed coatings of Al-Si/B{sub 4}C have been prepared on Al-Si piston alloys for diesel engine motors. The Al-Si/B{sub 4}C composite powders including 5-25 wt% B{sub 4}C were prepared by mixing and ball-milling processes. These powders were deposited on Al-Si substrate using an atmospheric plasma spray technique. The coatings have been characterised with respect to phase composition, microstructure, microhardness, bond strength and thermal expansion. It was found that Al, Si, B{sub 4}C and Al{sub 2}O{sub 3} phases were determined in the coatings with approximately 600 {mu}m thick by using X-ray diffraction analysis. Scanning electron microscope observation revealed that boron carbide particles were uniformly distributed in composite coatings and B{sub 4}C particles were fully wetted by Al-Si alloy. Also, no reaction products were observed in Al-Si/B{sub 4}C composite coatings. It was found that surface roughness, porosity, bond strength and thermal expansion coefficient of composite coatings decreased with increasing fraction of the boron carbide particle. It was demonstrated that the higher the B{sub 4}C content, the higher the hardness of coatings because the hardness of B{sub 4}C is higher than that of Al-Si.

  5. Fluctuations of charge variance and interaction time for dissipative processes in 27 Al + 27 Al collision

    International Nuclear Information System (INIS)

    Berceanu, I.; Andronic, A.; Duma, M.

    1999-01-01

    The systematic studies of dissipative processes in light systems were completed with experiments dedicated to the measurement of the excitation functions in 19 F + 27 Al and 27 Al + 27 Al systems in order to obtain deeper insight on DNS configuration and its time evolution. The excitation function for 19 F + 27 Al system evidenced fluctuations larger than the statistical errors. Large Z and angular cross correlation coefficients supported their non-statistical nature. The energy dependence of second order observables, namely the second moment of the charge distribution and the product ω·τ (ω - the angular velocity of the DNS and τ its mean lifetime) extracted from the angular distributions were studied for 19 F + 27 Al case. In this contribution we are reporting the preliminary results of similar studies performed for 27 Al + 27 Al case. The variance of the charge distribution were obtained fitting the experimental charge distribution with a Gaussian centered on Z = 13 and the product ω·τ was extracted from the angular distributions. The results for 19 F + 27 Al case are confirmed by a preliminary analysis of the data for 27 Al + 27 Al system. The charge variance and ω·τ excitation functions for Z = 11 fragment are represented together with the excitation function of the cross section. One has to mention that the data for 27 Al + 27 Al system were not corrected for particle evaporation processes. The effect of the evaporation corrections on the excitation function was studied using a Monte Carlo simulation. The α particle evaporation was also included and the evaluation of the particle separation energies was made using experimental masses of the fragments. The excitation functions for 27 Al + 27 Al system for primary and secondary fragments were simulated. No structure due to particle evaporation was observed. The correlated fluctuations in σ Z and ω·τ excitation functions support a stochastic exchange of nucleons as the main mechanism for

  6. Unprecedented Al supersaturation in single-phase rock salt structure VAlN films by Al+ subplantation

    Science.gov (United States)

    Greczynski, G.; Mráz, S.; Hans, M.; Primetzhofer, D.; Lu, J.; Hultman, L.; Schneider, J. M.

    2017-05-01

    Modern applications of refractory ceramic thin films, predominantly as wear-protective coatings on cutting tools and on components utilized in automotive engines, require a combination of excellent mechanical properties, thermal stability, and oxidation resistance. Conventional design approaches for transition metal nitride coatings with improved thermal and chemical stability are based on alloying with Al. It is well known that the solubility of Al in NaCl-structure transition metal nitrides is limited. Hence, the great challenge is to increase the Al concentration substantially while avoiding precipitation of the thermodynamically favored wurtzite-AlN phase, which is detrimental to mechanical properties. Here, we use VAlN as a model system to illustrate a new concept for the synthesis of metastable single-phase NaCl-structure thin films with the Al content far beyond solubility limits obtained with conventional plasma processes. This supersaturation is achieved by separating the film-forming species in time and energy domains through synchronization of the 70-μs-long pulsed substrate bias with intense periodic fluxes of energetic Al+ metal ions during reactive hybrid high power impulse magnetron sputtering of the Al target and direct current magnetron sputtering of the V target in the Ar/N2 gas mixture. Hereby, Al is subplanted into the cubic VN grains formed by the continuous flux of low-energy V neutrals. We show that Al subplantation enables an unprecedented 42% increase in metastable Al solubility limit in V1-xAlxN, from x = 0.52 obtained with the conventional method to 0.75. The elastic modulus is 325 ± 5 GPa, in excellent agreement with density functional theory calculations, and approximately 50% higher than for corresponding films grown by dc magnetron sputtering. The extension of the presented strategy to other Al-ion-assisted vapor deposition methods or materials systems is straightforward, which opens up the way for producing supersaturated single

  7. Erudición y nostalgia. Al-Hanīn ilà l-awtān en el editor de al-Faraŷ ba,d al-šidda de al-Tanūjī

    Directory of Open Access Journals (Sweden)

    Garulo, Teresa

    2012-06-01

    Full Text Available If you want to read a book, a medieval Arabic book, that talks to you about man and his relation with power (God’s power or any kind of worldly power, or about daily life in 10th century Basra or Baghdad, you will probably choose al-Tanūkhī’s works. His Nishwār al-muhādara wa-l-mudhākara or al-Faraj ba,d al-shidda are so widely and so well provided with stories, anecdotes, historical narratives, etc., that you won’t be able to drop it and probably will forget to read the many comments and marginal notes by, Abbūd al-Shāljī, its editor. But if you are wise enough, you will read everything he writes, because you will find in his remarks not only a sustained scholarliness but a fascinating evocation of his life in Irak, mostly in the thirties, with its cooking, manners and customs, and a pang of nostalgia that deserves, I think, at least a note or a friendly comment. In this paper I try to analyse some of his nostalgic memories of Baghdad and its people and places.Uno de los temas clásicos de la literatura árabe, casi desde sus comienzos, es la nostalgia de la tierra natal (al-hanīn ilà l-awtān. Experiencia dolorosa de extrañamiento, que se nutre de las crisis políticas, la nostalgia ha dado lugar a obras que buscan recrear un pasado o unos lugares amados, que sólo la memoria es capaz de recuperar. En este artículo trato de mostrar cómo se articula la nostalgia de Iraq, y, más concretamente, de Bagdad, dentro del aparato crítico de al-Faraŷ ba,da l-šidda de al-Tanūjī (329-384/941-994 (con el apoyo de Nišwār al-muhādara, también de dicho autor en la edición de, Abbūd al-Šālŷī, publicada en los años setenta. La representación que hace al-Tanūjī de la vida cotidiana de la capital abbasí, expresada a través de un lenguaje claro y natural, en el que tienen cabida expresiones populares, suscita en al-Šālŷī toda una serie de remembranzas, sobre todo de sus años juveniles, que se desbordan en sus notas, e

  8. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... disease. Who Gets ALS? Although this disease can strike anyone, ALS is extremely rare in kids. According ... home to provide care that the family cannot handle alone. Living With Lou Gehrig's Disease Living with ...

  9. Difficulties on study of ISM 26Al and a possible new way to nucleosynthesize 26Al-SNIa

    International Nuclear Information System (INIS)

    Peng Qiuhe

    1995-01-01

    Some observational results of the 1.809 MeV gamma-ray emitted by decay of the interstellar medium (ISM) 26 Al, which are obtained by spacecraft during (1979-1992) are firstly introduced. Secondly, both Mg-Al chain and Ne-Na cycle of nuclear reactions are discussed. Thirdly, some new experiments of nuclear physics, which are related with the question of the ISM 26 Al(e.g. measurements of the cross section of the nuclear reactions in the MgAl chain and in the NeNa cycle) are introduced. Then, comparing some experiments of nuclear physics, some difficulties confronted on various models responsible for the ISM 26 Al are discussed. The conclusions are: 1) all of hydrostatic H-burning models and all current nova models are hard to provide enough ISM 26 Al to be detected; 2) SN II + SN I b models are promising on responsibility for the half of ISM 26 Al, although current SN II + SN I b models should be improved, besides. Proposal of a new way to nucleosynthesizse 26 Al, 14 N + 16 O→ 26 Al + α, is suggested. SNI a as a possible source of the ISM 26 Al is discussed (63 refs.)

  10. Effect of the interface in laminated composites of Al-1100 and Al-2024

    International Nuclear Information System (INIS)

    Godefroid, L.B.

    1983-01-01

    Laminated composites consisting of alternating layers of Al-1100 and Al-2024 were produced by hot rolling, with 45% Al-2024 volume fraction. These composites were subjected to cyclic thermal treatment (various numbers of cycles) and to isothermal treatment (various numbers of cycles) and to isothermal treatment (at peak temperature and for times equivalent to those of the thermal cycles. Microhardness, tensile and fatigue crack arrester modes) were studied in the initial state and after treatments. (E.G.) [pt

  11. La flexibilidad inflexible: estudios de caso de plantas maquiladoras electrónicas en el norte de México

    Directory of Open Access Journals (Sweden)

    Maria Eugenia De la O

    2002-01-01

    Full Text Available Uno de los supuestos más controvertidos sobre la modernización productiva en la década de 1990 fue el aparente surgimiento de un nuevo tipo de relación entre la gerencia y los trabajadores, lo que de ser cierto, significaría un cambio radical en el ámbito del trabajo. Bajo este razonamiento en el presente artículo se planteó dimensionar los efectos de la modernización productiva en la industria maquiladora de exportación de tipo electrónico, como uno de los sectores más propensos al cambio tecnológico y de organización debido a su vínculo con los mercados internacionales y las firmas corporativas de clase mundial. A través de cuatro estudios de caso fue posible identificar la complejidad que puede adquirir la modernización y la flexibilidad del trabajo en las empresas, al convertirse este proceso en una combinación de destreza manual al lado de las nuevas concepciones de uso de la fuerza de trabajo, de intensificación de la jornada laboral junto a nuevas presiones para el trabajador, así como renovadas formas de control y subordinación de los obreros, a la luz de los cambios tecnológicos y de organización en las empresas.

  12. AlGaN-Based Deep-Ultraviolet Light Emitting Diodes Fabricated on AlN/sapphire Template

    International Nuclear Information System (INIS)

    Li-Wen, Sang; Zhi-Xin, Qin; Hao, Fang; Yan-Zhao, Zhang; Tao, Li; Zheng-Yu, Xu; Zhi-Jian, Yang; Bo, Shen; Guo-Yi, Zhang; Shu-Ping, Li; Wei-Huang, Yang; Hang-Yang, Chen; Da-Yi, Liu; Jun-Yong, Kang

    2009-01-01

    We report on the growth and fabrication of deep ultraviolet (DUV) light emitting diodes (LEDs) on an AlN template which was grown on a pulsed atomic-layer epitaxial buffer layer. Threading dislocation densities in the AlN layer are greatly decreased with the introduction of this buffer layer. The crystalline quality of the AlGaN epilayer is further improved by using a low-temperature GaN interlayer between AlGaN and AlN. Electroluminescences of different DUV-LED devices at a wavelength of between 262 and 317 nm are demonstrated. To improve the hole concentration of p-type AlGaN, Mg-doping with trimethylindium assistance approach is performed. It is found that the serial resistance of DUV-LED decreases and the performance of DUV-LED such as EL properties is improved. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  13. Surface study and thickness control of thin Al2O3 film on Cu-9%Al(111) single crystal

    International Nuclear Information System (INIS)

    Yamauchi, Yasuhiro; Yoshitake, Michiko; Song Weijie

    2004-01-01

    We were successful in growing a uniform flat Al 2 O 3 film on the Cu-9%Al(111) surface using the improved cleaning process, low ion energy and short time sputtering. The growth of ultra-thin film of Al 2 O 3 on Cu-9%Al was investigated using Auger electron spectroscopy (AES) and a scanning electron microscope (SEM). The Al 2 O 3 film whose maximum thickness was about 4.0 nm grew uniformly on the Cu-9%Al surface. The Al and O KLL Auger peaks of Al 2 O 3 film shifted toward low kinetic energy, and the shifts were related to Schottky barrier formation and band bending at the Al 2 O 3 /Cu-9%Al interface. The thickness of Al 2 O 3 film on the Cu-9%Al surface was controlled by the oxygen exposure

  14. Microstructural and mechanical properties of Al-Mg/Al{sub 2}O{sub 3} nanocomposite prepared by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Safari, J., E-mail: safari.jam@gmail.com [Department of Material Science and Engineering, Shahid Bahonar University of Kerman, P.O. Box No. 76135-133, Kerman (Iran, Islamic Republic of); Akbari, G.H. [Department of Material Science and Engineering, Shahid Bahonar University of Kerman, P.O. Box No. 76135-133, Kerman (Iran, Islamic Republic of); Research Center for Mineral Industries, Shahid Bahonar University of Kerman, P.O. Box No. 76135-133, Kerman (Iran, Islamic Republic of); Shahbazkhan, A. [Islamic Azad University, Saveh Branch, Saveh (Iran, Islamic Republic of); Delshad Chermahini, M. [Materials and Energy Research Center, Karaj (Iran, Islamic Republic of)

    2011-09-29

    Highlights: > The presence of Mg has remarkable effects on crystallite size and lattice strain. > The solution of Mg in the Al matrix accelerates the mechanical milling stages. > The microhardness increased in the presence of Mg. > The presence of Mg has significant effect on lattice parameter. > Steady-state situation was occurred in presence of Mg. - Abstract: The effect of milling time on the microstructure and mechanical properties of Al and Al-10 wt.% Mg matrix nanocomposites reinforced with 5 wt.% Al{sub 2}O{sub 3} during mechanical alloying was investigated. Steady-state situation was occurred in Al-10Mg/5Al{sub 2}O{sub 3} nanocomposite after 20 h, due to solution of Mg into Al matrix, while the situation was not observed in Al/5Al{sub 2}O{sub 3} nanocomposite at the same time. For the binary Al-Mg matrix, after 10 h, the predominant phase was an Al-Mg solid solution with an average crystallite size 34 nm. Up to 10 h, the lattice strain increased to about 0.4 and 0.66% for Al and Al-Mg matrix, respectively. The increasing of lattice parameter due to dissolution of Mg atom into Al lattice during milling was significant. By milling for 10 h the dramatic increase in microhardness (155 HV) for Al-Mg matrix nanocomposite was caused by grain refinement and solid solution formation. From 10 to 20 h, slower rate of increasing in microhardness may be attributed to the completion of alloying process, and dynamic and static recovery of powders.

  15. Different magnetic behaviour of the Kondo compounds Al3Ce and Al11Ce3

    International Nuclear Information System (INIS)

    Benoit, A.; Flouquet, J.; Palleau, J.; Buevoz, J.L.

    1979-08-01

    Neutron diffraction experiments on the Al 3 Ce and Al 11 Ce 3 compounds have been performed on the multidetector of the I.L.L. high flux reactor. No magnetic structure has been detected on the Al 3 Ce compound down to 20 mK. This confirms the non magnetic ground state of Al 3 Ce. For Al 11 Ce 3 , two magnetic structures have been observed: a ferromagnetic one at 4.2 K and an antiferromagnetic one at 2 K. The antiferromagnetic structure, which corresponds to a propagation vector (0,0,1/3), implies a strong reduction of the magnetic moment of determined sites; this reflects the Kondo character of the compounds

  16. Cast AlSi9Cu4 alloy with hybride strenghtened by Fe{sub x}Al{sub y}-Al{sub 2}O{sub 3} composite powder

    Energy Technology Data Exchange (ETDEWEB)

    Piatkowski, J [Department of Materials Technology, Silesian University of Technology, Krasinskiego 8, 40-019 Katowice (Poland); Formanek, B, E-mail: jaroslaw.piatkowski@polsl.pl, E-mail: boleslaw.formanek@polsl.pl [Department of Materials Science, Silesian University of Technology, Krasinskiego 8, 40-019 Katowice (Poland)

    2011-05-15

    The main objective of the study was to develop a technology of dispersion strenghtened hypoeutectic Al-Si alloy. The article presented the materials and technology conception for producing aluminium matrix composite AlSi9Cu4Fe alloy with hybride reinforcement of Al{sub x}Fe{sub y} intermetallic and aluminium oxide powders. Composite powder obtained in mechanical agllomerisation mixture of elemental powders. Changes in the structure were confirmed by TA and ATD thermal analyses plotting the solidification curves, which showed a decrease in temperature T{sub liq} compared to the unmodified alloy and an exothermic effect originating from the crystallisation of eutectics with alloying elements. The examinations carried out by SEM and BSE as well as the determination of local chemical composition by EDX technique have characterised the structure of the alloy as containing some binary Al-Si-Al-Cu and Al-Fe eutectics and multicomponent eutectics.

  17. Optical microcavities and enhanced electroluminescence from electroformed Al-Al{sub 2}O{sub 3}-Ag diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hickmott, T. W. [Department of Physics, State University of New York at Albany, Albany, New York 12222 (United States)

    2013-12-21

    Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of Al-Al{sub 2}O{sub 3}-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of Al-Al{sub 2}O{sub 3}-Ag diodes with anodic Al{sub 2}O{sub 3} thicknesses between 12 nm and 30 nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0 eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0 eV, have been used to characterize EL. The voltage threshold for EL with the LP filter, V{sub LP}, is ∼1.5 V. V{sub LP} is nearly independent of Al{sub 2}O{sub 3} thickness and of temperature and is 0.3–0.6 V less than the threshold voltage for EL for the SP filter, V{sub SP}. EL intensity is primarily between 1.8 and 3.0 eV when the bias voltage, V{sub S} ≲ 7 V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing V{sub S}, for diodes with the smallest Al{sub 2}O{sub 3} thicknesses, there is a maximum EL intensity, L{sub MX}, at a voltage, V{sub LMX}, followed by a decrease to a plateau. L{sub MX} and EL intensity at 4.0 V in the plateau region depend exponentially on Al{sub 2}O{sub 3} thickness. The ratio of L{sub MX} at 295 K for a diode with 12 nm of Al{sub 2}O{sub 3} to L{sub MX} for a diode with 25 nm of Al{sub 2}O{sub 3} is ∼140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ∼3 and ∼35; it depends on Al{sub 2}O{sub 3} thickness and V{sub S}. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and Al films to create surface plasmon polaritons (SPPs) at the metal-Al{sub 2}O

  18. Microstructure and Properties of Fe3Al-Fe3AlC x Composite Prepared by Reactive Liquid Processing

    Science.gov (United States)

    Verona, Maria Nalu; Setti, Dalmarino; Paredes, Ramón Sigifredo Cortés

    2018-04-01

    A Fe3Al-Fe3AlC x composite was prepared using reactive liquid processing (RLP) through controlled mixture of carbon steel and aluminum in the liquid state. The microstructure and phases of the composite were assessed using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, optical microscopy, and differential scanning calorimetry. In addition, the density, hardness, microhardness, and elastic modulus were evaluated. The Fe3Al-Fe3AlC x composite consisted of 65 vol pct Fe3Al and 35 vol pct Fe3AlC x ( κ). The κ phase contained 10.62 at. pct C, resulting in the stoichiometry Fe3AlC0.475. The elastic modulus of the Fe3Al-Fe3AlC0.475 composite followed the rule of mixtures. The RLP technique was shown to be capable of producing Fe3Al-Fe3AlC0.475 with a microstructure and properties similar to those achieved using other processing techniques reported in the literature.

  19. Appiah-Adjei et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    ing, sale of automobile spare parts, and metal fabrication. Some of these activities generate huge ... Keywords: Groundwater quality, pollution, waste disposal, Suame, Ghana ... of fertilizers (Chen et al., 2007; Parris, 2011;. Shen et al., 2011), ...

  20. KONSEP MᾹQᾹṢID AL-SYᾹRĪAH MENURUT ṬᾹHᾹ JᾹBIR AL-‘ALWᾹNĪ

    Directory of Open Access Journals (Sweden)

    Chasnak Najidah

    2017-03-01

    Full Text Available One discourse which is receiving considerable attention from scholars of Islam is about the objectives of Islamic law (maqasid al-shari'ah. Taha Jabir al-'Alwānī as one reviewer of Maqasid al-shari'ah contemporary formulate the concept of maqasid al-shari'ah different from previous scholars. This article describes the concept of maqasid al-shari'ah by Taha Jabir al-'Alwānī. According to him, there are three levels of hierarchical of Maqasid al-Sharia. The highest value of maqasid al-shari'ah says is what he describes as al-Maqasid al-'ulyā al-Hakimah (intentions of the highest shari'ah and a legal basis, which consists of three main elements, namely al-Tawhid ( Onesess of God, al-Tazkiyah (purification and al-'umrān (prosperity. The position of the second al-shari'ah Maqasid are universal values such as justice, freedom, and equality. While the third position is the formulation of the previous scholars regarding maqasid al-shari'ah consisting of ḍarūriyyat, ḥājiyyāt, and taḥsīniyyāt. In terms of methodological, Taha Jabir al-'Alwānī basing the new system for Maqasid al-syarī'ahnya on the methods of al-jam'u Baina al-qirā'atain, a reading of the two entities: the revelation of God and the universe. With this basis, he argues that the maqasid al-shari'ah formulations are qaṭ'ī, so it can be a reference to the scholars in solving the problems of contemporary law.   [Salah satu diskursus yang mendapat perhatian cukup besar dari para akademisi Islam adalah seputar tujuan-tujuan hukum islam  (maqāṣid al-syarī'ah. Ṭāhā Jābir al-‘Alwānī sebagai salah satu ulama pengkaji maqāṣid asy-syarī’ahkontemporer merumuskan konsep maqāṣid asy-syarī’ahyang berbeda dari ulama sebelumnya. Artikel ini mendeskripsikan konsep maqāṣid asy-syarī’ahmenurut Ṭāhā Jābir al-‘Alwānī. Menurutnya, ada tiga tingkatan hierarkis maqāṣid al-syarī'ah. Nilai tertinggi maqāṣid asy-syarī’ahmenurutnya adalah apa

  1. Measurement of the d({sup 26}Al{sup m},p){sup 27}Al reaction for nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Roeder, B.T.; Trache, L.; Iacob, V.E.; McCleskey, M.; Simmons, E.; Spiridon, A.; Tribble, R.E. [Texas A and M Univ., TX (United States); Davinson, T.; Lotay, G.; Woods, P.J. [University of Edinburgh (United Kingdom); La Cognata, M.; Pizzone, R.G.; Rapisarda, G.G.; Sparta, R.; Spitaleri, C. [Istituto Nazionale di Fisica Nucleare (LNS/INFN), Catania (Italy). Lab. Nazionali del Sud

    2012-07-01

    Full text: The detection of gamma rays from the decay of the {sup 26}Al ground state in the galaxy gives evidence that nucleosynthesis is occurring in present-day stars, but its origin is not yet clear. This implies that reactions involving {sup 26}Al are important for astrophysical processes. In a recent experiment at the Cyclotron Institute at Texas A and M University, reactions with the ground state and isomeric state of {sup 26}Al were investigated with the Texas A and M-Edinburgh-Catania Silicon detector Array (TECSA). TECSA is a collaborative effort to build a high-efficiency detector Si array useful for measuring reactions of interest for nuclear astrophysics and nuclear structure. The array consists of up to 16 Micron Semiconductor YY1 detectors that are each 300 μm thick. Each detector has 16 annular ring sectors to measure the energy and the scattering angle of the detected particles. Using TECSA, we measured d({sup 26}Al{sup g},p){sup 27}Al and d({sup 26}Al{sup m},p){sup 27}Al with a {sup 26}Al secondary beam prepared in-flight with the MARS spectrometer. First, the composition of the {sup 26}Al beam was determined by measuring the ratio of beta-decays to {sup 26}Al ions produced. It was found that at different spectrometer rigidities, beams of 2/3 isomer to ground state ratio or vice-versa could be obtained. Then, in the second part of the experiment, angular distributions were measured for both reactions at backward angles with TECSA. The protons were measured in TECSA in coincidence with timing signals from the beam detected by a scintillator and with the cyclotron radio-frequency. Details of the experiment and preliminary results from the analysis of the d({sup 26}Al{sup m},p){sup 27}Al and d({sup 26}Al{sup g},p){sup 27}Al data will be presented. They will give information about the proton capture reactions {sup 26}Al{sup m}(p,γ){sup 27}Si and {sup 26}Al{sup g}(p,γ){sup 27}Si taking place in stars. (author)

  2. Khajeh Nasir al-Din al-Tusi’s Role in the Interaction of Triple Paradigms of Islamic Philosophy

    Directory of Open Access Journals (Sweden)

    r Mohammadzadeh

    2013-09-01

    Full Text Available Our aim in this article is to investigate Khajeh Nasir`s effective role in emergence, growth and development of triple paradigms of Islamic philosophy, that are, Masha’, Ishraq and al-Hekmah al-Motealiyeh. Thus, first we present a summary of the meaning of “paradigm” and then discuss Tusi`s role in the development of triple paradigms of Islamic philosophy. We believe that, by using an interactive approach, Khajeh Nasir has attained a new approach to understand the paradigms. He is the first thinker in Islamic world who created a constructive and effective interaction between two paradigms of Masha’ and Ishraq, and paved the way for the emergence of al-Hekmah al-Motealiyeh. This can be explained with regard to either the conceptualization of al-Hekmat al-Motealiyeh or epistemological approach. Al-Hekmah Al-Motealiyah was influenced a lot by Tusi.

  3. Characterization of microstructure and mechanical properties of friction stir welded AlMg5- Al_2O_3 nanocomposites

    International Nuclear Information System (INIS)

    Babu, N. Kishore; Kallip, Kaspar; Leparoux, Marc; AlOgab, Khaled A.; Reddy, G.M.; Talari, M.K.

    2016-01-01

    In the present study, powder metallurgy processed unmilled AlMg5, milled AlMg5 and milled AlMg5-0.5 vol% Al_2O_3 nanocomposite have been successfully friction stir welded (FSW). The effect of friction stir welding on the evolution of weld microstructures; hardness and tensile properties were studied and discussed in detail. FSW of unmilled AlMg5 resulted in significant grain refinement and strain hardening in the nugget zone induced by the thermo-mechanical processing, thereby increasing the stir zone hardness and tensile strengths to 100 HV and 324 MPa when compared to 80 HV and 300 MPa of base metal, respectively. In contrast, the FSW of milled AlMg5 and milled AlMg5-0.5 vol% Al_2O_3 samples showed a reduction in UTS values to 375 MPa and 401 MPa in the stir zone compared to 401 MPa and 483 MPa of respective base metal values. Transmission electron microscopic (TEM) investigation of weld stir zones revealed the homogenous distribution of Al_4C_3 nanophases in milled AlMg5 and Al_2O_3 nanoparticles in milled AlMg5-0.5 vol% Al_2O_3 samples throughout the aluminium matrix. It was revealed that the pre-stored energy from the prior ball milling and hot pressing processes, higher deformation energy and grain boundary pinning effect due to the presence of reinforcement particles has resulted in a higher recrystallization tendency and retarded grain growth during FSW of milled samples. The welds prepared with milled AlMg5-0.5 vol% Al_2O_3 exhibited higher hardness and tensile strength in the stir zone when compared to all other conditions which was attributed to Hall Petch effect due to fine grain size and Orowan strengthening effect due to Al_2O_3 reinforcements.

  4. Experimental investigation of the Al-Y phase diagram

    International Nuclear Information System (INIS)

    Liu Shuhong; Du Yong; Xu Honghui; He Cuiyun; Schuster, Julius C.

    2006-01-01

    The Al-Y phase diagram has been reinvestigated with 16 key alloys over its whole composition range by means of differential thermal analysis, X-ray diffraction, optical microscopy, and scanning electron microscopy with energy dispersive X-ray techniques. The existence of five intermetallic phases, Al 3 Y, Al 2 Y, AlY, Al 2 Y 3 , and AlY 2 , has been confirmed. Al 2 Y and Al 2 Y 3 melt congruently at 1490 ± 2 and 1105 ± 2 deg. C, respectively. Al 3 Y, AlY, and AlY 2 are formed via the peritectic reactions L + Al 2 Y ↔ Al 3 Y at 980 ± 2 deg. C, L + Al 2 Y ↔ AlY at 1138 ± 2 deg. C, and L + Al 2 Y 3 ↔ AlY 2 at 977 ± 2 deg. C, respectively. Three eutectic reactions L ↔ (Al) + Al 3 Y at 637 ± 2 deg. C, L ↔ AlY + Al 2 Y 3 at 1081 ± 2 deg. C, and L ↔ AlY 2 + (αY) at 955 ± 2 deg. C , are observed. The previously reported Al 3 Y 5 , AlY 3 compounds were not found. A revised Al-Y phase diagram is presented mainly based on the present experimental results

  5. The corrosion and mechanical behaviour of Al, FeCrAlY, and CoCrAlY coatings in aggressive environments

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Haanappel, V.A.C.; Geerdink, Bert; Fransen, T.; Gellings, P.J.

    1991-01-01

    The mechanical and chemical behaviours of aluminide coatings applied by pack cementation, FeCrAlY coatings applied by plasma spraying and CoCrAlY coatings applied by electrodeposition were studied. The coatings were pretreated for 0.5 h in argon at 1373 K to improve the adhesion and structural

  6. Precipitation and strengthening phenomena in Al-Si-Ge and Al-Cu-Si-Ge alloys

    International Nuclear Information System (INIS)

    Mitlin, D.; Morris, J.W.; Dahmen, U.; Radmilovic, V.

    2000-01-01

    The objective of this work was to determine whether Al rich Al-Si-Ge and 2000 type Al-Cu-Si-Ge alloys have sufficient hardness to be useful for structural applications. It is shown that in Al-Si-Ge it is not possible to achieve satisfactory hardness through a conventional heat treatment. This result is explained in terms of sluggish precipitation of the diamond-cubic Si-Ge phase coupled with particle coarsening. However, Al-Cu-Si-Ge displayed a uniquely fast aging response, a high peak hardness and a good stability during prolonged aging. The high hardness of the Cu containing alloy is due to the dense and uniform distribution of fine θ' precipitates (metastable Al 2 Cu) which are heterogeneously nucleated on the Si-Ge particles. High resolution TEM demonstrated that in both alloys all the Si-Ge precipitates start out, and remain multiply twinned throughout the aging treatment. Since the twinned section of the precipitate does not maintain a low index interface with the matrix, the Si-Ge precipitates are equiaxed in morphology. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  7. Bankole et al (2)

    African Journals Online (AJOL)

    DELL

    Relationships of Clay-filled Channels on the Delta Flanks (Modified after Doust and Omatsola, 1990 and Lawrence et al., 2002). ... and in the Indo-Malaysian area (Germeraad et al.,. 1968). The genus ..... Upper Cretaceous of British Guiana.

  8. 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...

  9. The removal of bisphenol A from aqueous solutions by MIL-53(Al) and mesostructured MIL-53(Al).

    Science.gov (United States)

    Zhou, Meimei; Wu, Yi-Nan; Qiao, Junlian; Zhang, Jing; McDonald, Amanda; Li, Guangtao; Li, Fengting

    2013-09-01

    In this work, metal-organic framework MIL-53(Al){Al(OH)[O2C-C6H4-CO2]} and MIL-53(Al)-F127{Al(OH)[O2C-C6H4-CO2]} were synthesized and used as sorbents to remove bisphenol A (BPA) from aqueous system. The sorption kinetics data of BPA were found to be in agreement with the pseudo-second-order model. The equilibrium sorption amounts of BPA on MIL-53(Al) and MIL-53(Al)-F127 reached 329.2±16.5 and 472.7±23.6 mg g(-1), respectively, far more than that of commercial activated carbons (ranging from 129.6 to 263.1 mg g(-1)). Both MIL-53(Al) and MIL-53(Al)-F127 could remove BPA fast from aqueous solutions, and the required contact time to reach equilibrium was approximately 90 min for MIL-53(Al) and 30 min for MIL-53(Al)-F127, respectively. The optimum pH levels for the removal of BPA using MIL-53 (Al) and MIL-53(Al)-F127 were 4 and 6 separately. The optimum temperature for the sorption behavior of BPA on the two sorbents was 20 °C. The results performed show that the resulting products, as one kind of MOFs, can be regarded as a new class of sorbents for water treatment and could find great applications in the fields of environmental water pollution control and resources reuse. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Hyperfine fields and spin relaxation of Ce in GdAl2 and DyAl2

    International Nuclear Information System (INIS)

    Waeckelgaard, E.; Karlsson, E.; Lindgren, B.; Mayer, A.

    1987-04-01

    We have investigated the ferromagnetic state of the cubic intermetallic compounds GdAl 2 and DyAl 2 with the 140 Ce nuclei using DPAC. The local fields of Ce are for the lowest measured temperatures B eff (30 K) = 54(2) T for GdAl 2 and B eff (12.5 K) = 27(1) T for DyAl 2 which are considerably lower than the hyperfine field measured for a free Ce ion (183 T). By introducing a crystal field, of cubic symmetry, a lower hyperfine field is obtained which is in quantitative agreement with the local field of Ce in GdAl 2 . For DyAl 2 an additional effect, represented by a non-magnetic level below the lowest magnetic level, may explain a further reduction of the hyperfine field. Two models relating to a Kondo non-magnetic state of Ce are discussed. Spin relaxation in the paramagnetic state are also studied and compared with observations of the same systems measured with μSR. (authors)

  11. Experimental evidence of structural transition at the crystal-amorphous interphase boundary between Al and Al2O3

    International Nuclear Information System (INIS)

    Yang, Z.Q.; He, L.L.; Zhao, S.J.; Ye, H.Q.

    2002-01-01

    High-resolution transmission electron microscopy observations on the structure of the interphase boundary between crystalline Al and amorphous Al 2 O 3 coating reveal that an interfacial melting transition of Al occurs at 833 K, which is distinctly lower than the bulk melting point of Al. The crystalline lattice planes of Al near the interface bend or small segments of crystalline Al deviated from the matrix Al grains are formed. Stand-off dislocations formed at the interphase boundary are also observed. The amorphous Al 2 O 3 coating plays an important role in retaining the evidence for structural transition at high temperature to room temperature, which makes it possible to make experimental observations. (author)

  12. Room-Temperature Quantum Ballistic Transport in Monolithic Ultrascaled Al-Ge-Al Nanowire Heterostructures.

    Science.gov (United States)

    Sistani, Masiar; Staudinger, Philipp; Greil, Johannes; Holzbauer, Martin; Detz, Hermann; Bertagnolli, Emmerich; Lugstein, Alois

    2017-08-09

    Conductance quantization at room temperature is a key requirement for the utilizing of ballistic transport for, e.g., high-performance, low-power dissipating transistors operating at the upper limit of "on"-state conductance or multivalued logic gates. So far, studying conductance quantization has been restricted to high-mobility materials at ultralow temperatures and requires sophisticated nanostructure formation techniques and precise lithography for contact formation. Utilizing a thermally induced exchange reaction between single-crystalline Ge nanowires and Al pads, we achieved monolithic Al-Ge-Al NW heterostructures with ultrasmall Ge segments contacted by self-aligned quasi one-dimensional crystalline Al leads. By integration in electrostatically modulated back-gated field-effect transistors, we demonstrate the first experimental observation of room temperature quantum ballistic transport in Ge, favorable for integration in complementary metal-oxide-semiconductor platform technology.

  13. Fabricación y caracterización de aleaciones porosas de Ti y Ti6Al4V producidas mediante sinterización con espaciador

    Directory of Open Access Journals (Sweden)

    Tojal, C.

    2013-02-01

    Full Text Available Titanium is well-known to be a biocompatible material with good corrosion properties and good strength, taking into account their low specific weight. In powder metallurgy field, titanium has been used in order to obtain porosity materials for biomedical applications. Recently, porous materials have been investigated for their use like hips implants. The principal reason is based on a reduction of stiffness implants, minimizing effects of stress shielding. The purpose of the present work is produced porous materials by space holder technique using ammonium bicarbonate like spacer. Scaffolds of titanium have been fabricated by powders of titanium with different grades of particle size and compacting pressure. Before sintering, stability of green parts has been studied by mechanical test. After sintering, porosity has been evaluated besides mechanical properties and elastic modulus by three points bending test. The microstructural characterisation is performed by optical and electron microscopy.

    El titanio es un material biocompatible que, además de presentar buenas propiedades a la corrosión, posee una elevada resistencia mecánica teniendo en cuenta su baja densidad. En el campo de la pulvimetalurgia, entre otras aplicaciones, este material se usa con objeto de obtener materiales porosos para aplicaciones biomédicas. Recientemente se ha investigado la aplicación de los materiales porosos en la fabricación de implantes de cadera. La razón principal está basada en la reducción de la rigidez de los implantes, lo cual minimiza los efectos del “apantallamiento de tensiones”, al aproximarse su módulo elástico al del hueso. El propósito del presente trabajo, es producir materiales porosos mediante la técnica de sinterización con espaciador, usando el bicarbonato de amonio como propulsor de la formación de poros. Para la obtención de los mismos, se ha utilizado polvo de titanio de diferentes tamaños de partícula, usando

  14. The effectiveness of ERC advanced life support (ALS) provider courses for the retention of ALS knowledge.

    Science.gov (United States)

    Fischer, Henrik; Strunk, Guido; Neuhold, Stephanie; Kiblböck, Daniel; Trimmel, Helmut; Baubin, Michael; Domanovits, Hans; Maurer, Claudia; Greif, Robert

    2012-02-01

    Out-of-hospital emergency physicians in Austria need mandatory emergency physician training, followed by biennial refresher courses. Currently, both standardized ERC advanced life support (ALS) provider courses and conventional refresher courses are offered. This study aimed to compare the retention of ALS-knowledge of out-of-hospital emergency physicians depending on whether they had or had not participated in an ERC-ALS provider course since 2005. Participants (n=807) from 19 refresher courses for out-of-hospital emergency physicians answered eight multiple-choice questions (MCQ) about ALS based on the 2005 ERC guidelines. The pass score was 75% correct answers. A multivariate logistic regression analyzed differences in passing scores between those who had previously participated in an ERC-ALS provider course and those who had not. Age, gender, regularity of working as an out-of-hospital emergency physician and the self-reported number of real resuscitation efforts within the last 6months were entered as control variables. Out-of-hospital emergency physicians who had previously attended an ERC-ALS provider course had a significantly higher chance of passing the MCQ test (OR=1.60, p=0.015). Younger age (OR=0.95, pERC-ALS provider course since 2005 had a higher retention of ALS knowledge compared to non-ERC-ALS course participants. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. X-ray study of rapidly cooled ribbons of Al-Cr-Zr and Al-Ni-Y-Cr-Zr alloys

    International Nuclear Information System (INIS)

    Betsofen, S.Ya.; Osintsev, O.E.; Lutsenko, A.N.; Konkevich, V.Yu.

    2002-01-01

    One investigated into phase composition, lattice spacing and structure of rapidly cooled 25-200 μm gauge strips made of Al-4,1Cr-3,2Zr and Al-1,5Cr-1,5Zr-4Ni-3Y alloys, wt. %, produced by melt spinning to a water-cooled copper disk. In Al-4,1Cr-3,2Zr alloy one detected intermetallic phases: Al 3 Zr and two Al 86 Cr 14 composition icosahedral phases apart from aluminium solid solution with 4.040-4.043 A lattice spacing. In Al-1,5Cr-1,5Zr-4Ni-3Y alloy one identified two Al 86 Cr 14 icosahedral phases and two AlNiY and Al 3 Y yttrium-containing ones, lattice spacing of aluminium solid solution was equal to 4.052-4.053 A [ru

  16. The Influence of the Asymmetric Arb Process on the Properties of Al-Mg-Al Multi-Layer Sheets / Wpływ Asymetrii W Procesie Arb Na Właściwości Wielowarstwowych Blach Al-Mg-Al

    Directory of Open Access Journals (Sweden)

    Wierzba A.

    2015-12-01

    Full Text Available The paper presents the results of the experimental study of the three-layer Al-Mg-Al sheets rolling process by the ARB method. The tests carried out were limited to single-pass symmetric and asymmetric rolling processes. An Al-Mg-Al package with an initial thickness of 4 mm (1-2-1 mm was subjected to the process of rolling with a relative reduction of 50%. To activate the shear band in the strip being deformed, an asymmetry factor of av=2 was applied. From the test results, an increase in the tensile strength of the multi-layer Al-Mg-Al sheets obtained from the asymmetric process was observed. Microhardness tests did not show any significant differences in aluminium layer between respective layers of sheets obtained from the symmetric and the asymmetric process. By contrast, for the magnesium layer, an increase in microhardness from 72 HV to 79 HV could be observed for the asymmetric rolling. The analysis of the produced Al-Mg-Al sheets shows that the good bond between individual layers and grain refinement in the magnesium layer contributed to the obtaining of higher mechanical properties in the multi-layer sheets produced in the asymmetric process compared to the sheets obtained from the symmetric process.

  17. The investigation of Al0.29Ga0.71N/GaN/AlN and AlN/GaN/AlN thin films grown on Si (111) by RF plasma-assisted MBE

    Science.gov (United States)

    Yusoff, Mohd Zaki Mohd; Mahyuddin, Azzafeerah; Hassan, Zainuriah; Hassan, Haslan Abu; Abdullah, Mat Johar

    2012-06-01

    Recently, gallium nitride (GaN) and its related compounds involving Al and In have attracted much attention because of their potential to be used as high-efficiency UV light emitting devices, and as high frequency and high power electronic devices. Consequently, the growth and physics of GaN-based materials have attracted remarkable scientific attention. In this work, the growth and characterization of epitaxial Al0.29Ga0.71N and AlN layers grown on Si (111) by RF-plasma assisted molecular beam epitaxy (MBE) are described. The Al mole fraction was derived from the HR-XRD symmetric rocking curve (RC) ω/2θ scans of (0002) plane as x = 0.29. For AlN/GaN/AlN sample, the maximum Raman intensity at 521.53 cm-1 is attributed to crystalline silicon. It was found that the allowed Raman optical phonon mode of GaN, the E1 (high) is clearly visible, which is located at 570.74 cm-1. Photoluminscence (PL) spectrums of both samples have shown sharp and intense band edge emission of GaN without the existence of yellow emission band, showing good crystal quality of the samples have been successfully grown on Si substrate.

  18. Field ion microscopy and 3-D atom probe analysis of Al3Zr particles in 7050 Al alloy

    International Nuclear Information System (INIS)

    Sha, G.; Cerezo, A.

    2004-01-01

    Full text: For high strength 7xxx series Al alloys, Zr is an important trace alloy element which is often added to optimise properties, having effects such as refining grain size, inhibiting recrystallization, and improving stress corrosion cracking resistance and quench sensitivity. In addition, it has been reported recently that Zr addition also has a significant influence on early stage ageing behaviour of a 7xxx series Al alloy. Zr equilibrium solubility in solid Al is extremely low. After solution or ageing treatment, most Zr is present as small spherical Ai 3 Zr dispersoids approximately 20 nm in diameter, distributed at grain boundaries as well as within the Al matrix. The crystallographic nature of intermetallic phase Al 3 Zr has been well studied in the literatures. So far, no direct measurement of the chemistry of the Al 3 Zr particles in 7xxx series Al alloys has been published. It is unclear if there is significant Zn, Mg or Cu included in the particles. In this research, 3DAP has been employed for the first time to investigate ionisation behaviour of Al 3 Zr particles and determine the chemistry of the particles in 7050 Al alloy. Using field ion microscopy, the local evaporation radius of the Al 3 Zr particle has been measured to be equivalent to 36 nm for a 10 kV tip, less than the equivalent tip radius for the Al matrix of ∼68 nm. Using the matrix Al evaporation field (19 V/nm) as a reference, this allows the evaporation field of Al 3 Zr to be calculated as 35 V/nm, the same as the field calculated for evaporation of Al as Al 2+ (35 V/nm), and that of Zr as Zr 3+ (35 V/nm). This result is consistent with Al 2+ and Zr 3+ being the main species observed in the mass spectrum during analysis of Al 3 Zr particles. Using 3DAP, the chemical compositions of Al 3 Zr particles are determined to be 64.8∼67.7 at% Al, 23.6∼24.8 at% Zr, 6.9∼9.1 at% Zn, 0.4∼0.7 at% Cu, 0.5∼1.2 at% Mg, with a (Al+Zn)/Zr ratio close to 3. Choice of specimen temperature of

  19. Synthesis and structural transformations of hydrotalcite-like materials Mg-Al and Zn-Al

    NARCIS (Netherlands)

    Prihod'ko, R.V.; Sychev, M.V.; Astrelin, I.M.; Erdmann, K.; Mangel, A.; Santen, van R.A.

    2001-01-01

    Mg-Al and Zn-Al hydrotalcite-like layered double hydroxides of various compositions were synthesized and characterized. A detailed comparative analysis of the structure and composition of starting and reconstructed layered double hydroxides was made

  20. Natural radioactivity survey in Al-Jabal Al-Gharbi Mountain Region Libya

    International Nuclear Information System (INIS)

    Askouri, N.A.; Hussain, M.O.; Al-Ojaily, A.S.

    2011-01-01

    The measurement of natural radioactivity in a given region or country is essential to provide a reference base-line map to follow up a possible variation in future. In order to perform such measurement, the natural radioactivity was measured in different locations. The locations (50 sites) were distributed over Al-Jabal Al-Gharbi Mountain, starting from the city Al-Azeeziah in the eastern part to Wazen on the Tunisian border in the west. The measurements showed obvious variation from one site to another. The levels were fluctuating from (12.8 counts/minute) in Bir-Ayad to (45.7 counts/minute) in Gherian. In order to investigate the cause for such variation, samples were collected from (27) sites for detailed study. The levels of natural radioactivity were determined in the laboratory, and were ranging from (58.7 Bq/kg) in Bir-Ayad to (102.1 Bq/kg) in Gherian. The variation in measured radioactivity was related to the geological structures taken in six perpendicular sections, namely, Gharian, Yevren, Zintan, Nalut, Wazen and Al-Azeeziah taking the naturally occurred radioisotopes concentration of 4 0K, 232 Th and 238 U present in consideration.

  1. Phase constituents and microstructure of laser cladding Al2O3/Ti3Al reinforced ceramic layer on titanium alloy

    International Nuclear Information System (INIS)

    Li Jianing; Chen Chuanzhong; Lin Zhaoqing; Squartini, Tiziano

    2011-01-01

    Research highlights: → In this study, Fe 3 Al has been chosen as cladding powder due to its excellent properties of wear resistance and high strength, etc. → Laser cladding of Fe 3 Al + TiB 2 /Al 2 O 3 pre-placed alloy powder on Ti-6Al-4V alloy substrate can form the Ti 3 Al/Fe 3 Al + TiB 2 /Al 2 O 3 ceramic layer, which can increase wear resistance of substrate. → In cladding process, Al 2 O 3 can react with TiB 2 leading to formation of Ti 3 Al and B. → This principle can be used to improve the Fe 3 Al + TiB 2 laser-cladded coating. - Abstract: Laser cladding of the Fe 3 Al + TiB 2 /Al 2 O 3 pre-placed alloy powder on Ti-6Al-4V alloy can form the Ti 3 Al/Fe 3 Al + TiB 2 /Al 2 O 3 ceramic layer, which can greatly increase wear resistance of titanium alloy. In this study, the Ti 3 Al/Fe 3 Al + TiB 2 /Al 2 O 3 ceramic layer has been researched by means of electron probe, X-ray diffraction, scanning electron microscope and micro-analyzer. In cladding process, Al 2 O 3 can react with TiB 2 leading to formation of amount of Ti 3 Al and B. This principle can be used to improve the Fe 3 Al + TiB 2 laser cladded coating, it was found that with addition of Al 2 O 3 , the microstructure performance and micro-hardness of the coating was obviously improved due to the action of the Al-Ti-B system and hard phases.

  2. Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy

    KAUST Repository

    Vlach, Martin

    2013-12-01

    The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al3Sc and/or Al3(Sc,Zr) particles precipitated during extrusion at 350 C in the alloys studied. Additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 C. The precipitation of the Al6Mn- and/or Al 6(Mn,Fe) particles of a size ~ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al3Sc particles formation and/or coarsening and that of the Al6Mn and/or Al 6(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al3Sc-phase and the Al 6Mn-phase precipitation. © 2013 Elsevier Inc.

  3. Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy

    KAUST Repository

    Vlach, Martin; Stulí ková , Ivana; Smola, Bohumil; Kekule, Tomá š; Kudrnová , Hana; Daniš, Stanislav; Gemma, Ryota; Očená šek, Vladivoj; Má lek, Jaroslav; Tanprayoon, Dhritti; Neubert, Volkmar

    2013-01-01

    The effects of cold-rolling on thermal, mechanical and electrical properties, microstructure and recrystallization behaviour of the AlScZr and AlMnScZr alloys prepared by powder metallurgy were studied. The powder was produced by atomising in argon with 1% oxygen and then consolidated by hot extrusion at 350 C. The electrical resistometry and microhardness together with differential scanning calorimetry measurements were compared with microstructure development observed by transmission and scanning electron microscopy, X-ray diffraction and electron backscatter diffraction. Fine (sub)grain structure developed and fine coherent Al3Sc and/or Al3(Sc,Zr) particles precipitated during extrusion at 350 C in the alloys studied. Additional precipitation of the Al3Sc and/or Al3(Sc,Zr) particles and/or their coarsening was slightly facilitated by the previous cold rolling. The presence of Sc,Zr-containing particles has a significant antirecrystallization effect that prevents recrystallization at temperatures minimally up to 420 C. The precipitation of the Al6Mn- and/or Al 6(Mn,Fe) particles of a size ~ 1.0 μm at subgrain boundaries has also an essential antirecrystallization effect and totally suppresses recrystallization during 32 h long annealing at 550 C. The texture development of the alloys seems to be affected by high solid solution strengthening by Mn. The precipitation of the Mn-containing alloy is highly enhanced by a cold rolling. The apparent activation energy of the Al3Sc particles formation and/or coarsening and that of the Al6Mn and/or Al 6(Mn,Fe) particle precipitation in the powder and in the compacted alloys were determined. The cold deformation has no effect on the apparent activation energy values of the Al3Sc-phase and the Al 6Mn-phase precipitation. © 2013 Elsevier Inc.

  4. Universitat popular al Cabanyal

    OpenAIRE

    Ribés Granell, Juan Miguel

    2012-01-01

    La intención es dotar al barrio de un gran espacio verde y de un edificio de interés para los vecinos que enriquezca al Cabanyal, ya que actualmente se encuentra en proceso de degradación. Se pretende desarrollar un proyecto que signifique una mejora en la predisposición del visitante, cubriendo sus necesidades. Al mismo tiempo, se busca crear un espacio arquitectónico que mejore la relación entre las actividades que incluye y su entorno. El proyecto está condicionado por cuatro aspectos fund...

  5. Modelling and simulation of the steam line, the high and low pressure turbines and the pressure regulator for the SUN-RAH nucleo electric university simulator; Modelado y simulacion de la linea de vapor, las turbinas de alta y de baja presion y el regulador de presion para el simulador universitario de nucleo electricas SUN RAH

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, A. [DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos, UNAM (Mexico)]. e-mail: andyskamx@yahoo.com.mx

    2003-07-01

    In the following article the development of a simulator that allows to represent the dynamics of the following systems: steam line, nozzle, vapor separator, reheater, high pressure turbine, low pressure turbine, power generator and the pressure regulator of a nucleo electric power station. We start from the supposition that this plant will be modeled from a nuclear reactor type BWR (Boiling Water Reactor), using models of reduced order that represent the more important dynamic variables of the physical processes that happen along the steam line until the one generator. To be able to carry out the simulation in real time the Mat lab mathematical modeling software is used, as well as the specific simulation tool Simulink. It is necessary to point out that the platform on which the one is executed the simulator is the Windows operating system, to allow the intuitive use that only this operating system offers. The above-mentioned obeys to that the objective of the simulator it is to help the user to understand some of the dynamic phenomena that are present in the systems of a nuclear plant, and to provide a tool of analysis and measurement of variables to predict the desirable behavior of the same ones. The model of a pressure controller for the steam lines, the high pressure turbine and the low pressure turbine is also presented that it will be the one in charge of regulating the demand of the system according to the characteristics and critic restrictions of safety and control, assigned according to those wanted parameters of performance of this system inside the nucleo electric plant. This simulator is totally well defined and it is part of the University student nucleo electric simulator with Boiling Water Reactor (SUN-RAH), an integral project and of greater capacity. (Author)

  6. Nonequilibrium synthesis of NbAl3 and Nb-Al-V alloys by laser cladding. II - Oxidation behavior

    Science.gov (United States)

    Haasch, R. T.; Tewari, S. K.; Sircar, S.; Loxton, C. M.; Mazumder, J.

    1992-01-01

    Isothermal oxidation behaviors of NbAl3 alloy synthesized by laser cladding were investigated at temperatures between 800 and 1400 C, and the effect of vanadium microalloying on the oxidation of the laser-clad alloy was examined. The oxidation kinetics of the two alloys were monitored using thermal gravimetric weight gain data, and the bulk and surface chemistries were analyzed using XRD and XPS, respectively. It was found that NbAl3 did not form an exclusive layer of protective Al2O3. The oxidation products at 800 C were found to be a mixture of Nb2O5 and Al2O3. At 1200 C, a mixture of NbAlO4, Nb2O5, and Al2O3 formed; and at 1400 C, a mixture of NbAlO4, Al2O3, NbO2, NbO(2.432), and Nb2O5 formed. The addition of V led to a dramatic increase of the oxidation rate, which may be related to the formation of (Nb, V)2O5 and VO2, which grows in preference to protective Al2O3.

  7. Completing the Heterocubane Family [Cp*AlE]4 (E = O, S, Se, and Te) by Selective Oxygenation and Sulfuration of [Cp*Al]4: Density Functional Theory Calculations of [Cp*AlE]4 and Reactivity of [Cp*AlO]4 toward Hydrolysis.

    Science.gov (United States)

    Stelzer, Adrian C; Hrobárik, Peter; Braun, Thomas; Kaupp, Martin; Braun-Cula, Beatrice

    2016-05-16

    The subvalent aluminum compound [Cp*Al]4 (1) reacts with dioxygen, N2O, or sulfur to yield the heterocubane complexes [Cp*AlX]4 [X = O (2) and S (3)]. Treatment of [Cp*AlO]4 (2) with (tBuO)3SiOH gave [(tBuO)3SiOAlO]4 (6) and Cp*H. The structures and spectroscopic data of the Al clusters are supported by density functional theory (DFT) calculations, which also demonstrate the importance of noncovalent interactions (NCI) in oligomeric Al(I) complexes as well as in [Cp*AlS]4 and the heavier homologues of Se and Te. The computed (27)Al NMR shifts indicate a deshielding at the Al centers with increasing electronegativity of the chalcogen atom as well as significant spin-orbit shielding effects within the heavier heterocubane [Al4E4] cores. Further hydrolysis of 6 with an additional amount of silanol in the presence of water resulted in the formation of [