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Sample records for al plomo relationship

  1. Exposición al plomo y su relación con el tiempo requerido para embarazo

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    Guerra-Tamayo Juan Luis

    2003-01-01

    Full Text Available OBJETIVO: Determinar los efectos de la exposición al plomo relacionados con el tiempo requerido para embarazo. MATERIAL Y MÉTODOS: Entre 1997 y 2001 se realizó un estudio en 142 mujeres residentes en la Ciudad de México, participantes en un estudio de cohorte para evaluar diversos efectos del plomo sobre la salud reproductiva. Se realizaron mediciones de plomo en sangre y en hueso a cada una de las participantes en el momento de ingresar al estudio, y se obtuvo información relativa a la exposición y otras variables de interés a través de un cuestionario. A cada una de las participantes se les siguió hasta el momento en que se embarazaron, o bien, hasta el tiempo de término del estudio, con el propósito de determinar la asociación entre la exposición al plomo y el tiempo requerido para quedar embarazada. El análisis estadístico se llevó a cabo utilizando curvas de Kaplan-Meier y modelos de riesgos proporcionales de Cox. RESULTADOS: Del total de mujeres que iniciaron el estudio se embarazaron 42, de las cuales 34 lo lograron antes del primer año de seguimiento y ocho posteriormente. Las medias de las concentraciones de plomo en sangre fueron de 9.3 µg/dl; en rótula y tibia fueron de 16.0 y 11.0 µg Pb/g de hueso mineral, respectivamente. No se detectaron diferencias en los niveles de plomo en sangre respecto al tiempo que durante el estudio requirió la mujer para embarazarse en el primer año; no obstante, se encontró que en las mujeres con plomo en sangre por encima de 10 µg/dl el riesgo de no embarazo fue cinco veces mayor [IC 95% (1.9-19.1] después de un año de seguimiento, comparado con aquellas mujeres con plomo en sangre por debajo de 10 µg/dl. CONCLUSIONES: La exposición a concentraciones altas de plomo puede ser un factor de riesgo importante en el tiempo requerido para que una mujer quede embarazada, principalmente en aquellas que siendo fértiles tienen periodos mayores de un año buscando un embarazo.

  2. Exposición al plomo y su relación con el tiempo requerido para embarazo Lead exposure and time to pregnancy

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    Juan Luis Guerra-Tamayo

    2003-01-01

    Full Text Available OBJETIVO: Determinar los efectos de la exposición al plomo relacionados con el tiempo requerido para embarazo. MATERIAL Y MÉTODOS: Entre 1997 y 2001 se realizó un estudio en 142 mujeres residentes en la Ciudad de México, participantes en un estudio de cohorte para evaluar diversos efectos del plomo sobre la salud reproductiva. Se realizaron mediciones de plomo en sangre y en hueso a cada una de las participantes en el momento de ingresar al estudio, y se obtuvo información relativa a la exposición y otras variables de interés a través de un cuestionario. A cada una de las participantes se les siguió hasta el momento en que se embarazaron, o bien, hasta el tiempo de término del estudio, con el propósito de determinar la asociación entre la exposición al plomo y el tiempo requerido para quedar embarazada. El análisis estadístico se llevó a cabo utilizando curvas de Kaplan-Meier y modelos de riesgos proporcionales de Cox. RESULTADOS: Del total de mujeres que iniciaron el estudio se embarazaron 42, de las cuales 34 lo lograron antes del primer año de seguimiento y ocho posteriormente. Las medias de las concentraciones de plomo en sangre fueron de 9.3 µg/dl; en rótula y tibia fueron de 16.0 y 11.0 µg Pb/g de hueso mineral, respectivamente. No se detectaron diferencias en los niveles de plomo en sangre respecto al tiempo que durante el estudio requirió la mujer para embarazarse en el primer año; no obstante, se encontró que en las mujeres con plomo en sangre por encima de 10 µg/dl el riesgo de no embarazo fue cinco veces mayor [IC 95% (1.9-19.1] después de un año de seguimiento, comparado con aquellas mujeres con plomo en sangre por debajo de 10 µg/dl. CONCLUSIONES: La exposición a concentraciones altas de plomo puede ser un factor de riesgo importante en el tiempo requerido para que una mujer quede embarazada, principalmente en aquellas que siendo fértiles tienen periodos mayores de un año buscando un embarazo

  3. Exposición infantil al plomo en sitios contaminados Children exposure to lead in contaminated sites

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    Rogelio Flores-Ramírez

    2012-08-01

    Full Text Available OBJETIVO: Determinar el grado de la exposición infantil al plomo en diversos tipos de sitios contaminados. MATERIAL Y MÉTODOS: El estudio se realizó de junio 2008 a diciembre 2009 en cuatro sitios de México: metalúrgica de Ávalos, Chihuahua.; metalúrgica de Morales, San Luis Potosí (SLP; zona alfarera en La Trinidad, Tlaxcala, y sitio minero en Cedral, SLP. Se cuantificó plomo en polvo y se realizó un biomonitoreo humano en niños de la comunidad. RESULTADOS: Los valores obtenidos de plomo en polvo exterior superaron el límite establecido de 400 mg/kg para suelos residenciales en un intervalo de valores para los cuatro sitios de 62 a 5 187 mg/kg. En cuanto al monitoreo biológico, todas las poblaciones presentaron valores extremos, desde los 22 µg/dL en Cedral, 31 µg/dL en Morales, y 32 µg/dL en Ávalos, hasta los 52 µg/dL en La Trinidad. Es importante señalar que encontramos una correlación positiva y significativa entre los valores de plomo en polvo y plomo en sangre en todos los sitios de estudio (pOBJECTIVE: To assess the exposure to lead in children living in various types of contaminated sites. MATERIALS AND METHODS: The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP; Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. RESULTS: Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead

  4. Contribución al estudio de la evolución y fuentes del plomo en la atmósfera del núcleo urbano de Oviedo

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    Fernández García, Bernardo

    1981-01-01

    Se han determinado por a.a. las concentraciones atmosféricas de plomo en el núcleo urbano de Oviedo. A partir de las relaciones encontradas entre dichas concentraciones y las correspondientes de los iones+ se ha calculado la intensidad media anual de la fuente de plomo utilizando un modelo de difusión. Así mismo, se ha procedido a realizar el balance del plomo emitido a la atmósfera de la ciudad de Oviedo por el tráfico de automóvil, estimándose dicho valor en unos 140 Kg. de plomo al día. ...

  5. Experiencias de la instauración de normas relativas al contenido de plomo en aire y el agua, en los Estados Unidos de América

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    Davis J Michael

    2003-01-01

    Full Text Available En los Estados Unidos de América se ha logrado una disminución de la exposición a plomo de la población en general, gracias al establecimiento de diversas normas. En este artículo se destaca parte de los conocimientos adquiridos a través de la experiencia obtenida en este país en materia de plomo, en particular respecto al aire y al agua. Uno de los aspectos fundamentales es la posibilidad de contar con una base científica sólidamente establecida y claramente entendida, a partir de la cual se tomarán las medidas correspondientes. Los efectos secundarios de ciertas normas concernientes al aire ponen de manifiesto de qué manera los esfuerzos orientados a solucionar un problema pueden aportar beneficios en otras áreas, si bien pueden surgir consecuencias no deseadas, debido a la falta de previsión y de evaluación. Asimismo, en este documento se discuten las diferencias entre los enfoques centralizados y los descentralizados para el manejo de la exposición a plomo.

  6. Eliminación del plomo por curado casero

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    Torres-Sánchez Luisa; López-Carrillo Lizbeth; Ríos Camilo

    1999-01-01

    Objetivo. Evaluar el curado ácido como medida preventiva para reducir el contenido de plomo en vasijas de barro vidriadas. Material y métodos. En 27 vasijas de barro procedentes de cuatro estados de México se determinó, mediante espectrofotometría de absorción atómica, el nivel de plomo residual, después de cuatro lavados con ácido acético al 3%. Resultados. El contenido de plomo en el ácido acético utilizado para lavar las vasijas disminuyó proporcionalmente con el número de lavados, aunque ...

  7. Niveles de plomo en sangre en niños de 8 a 10 años y su relación con la alteración en el sistema visomotor y del equilibrio Relationship of blood lead levels with visual-motor and equilibrium disturbances in children aged 8 to 10 years

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    María Isabel Azcona-Cruz

    2000-08-01

    equilibrio. CONCLUSIONES: La relación negativa entre el plomo y la habilidad visomotora concuerda con los resultados encontrados en niños en otros países. Al parecer las concentraciones de plomo en sangre, que son comunes en los niños de Oaxaca, son suficientes para ocasionar una limitación visomotora de naturaleza sutil. Los resultados de este estudio señalan la necesidad de reforzar la iniciativa de reducir la exposición de los niños a las fuentes de exposición conocidas, en especial barro vidriado y, por lo tanto, reducir los niveles poblacionales de plomo en sangre.OBJECTIVE: To assess the association betwen blood lead concentrations and visual-motor coordination and equilibrium in school age children. MATERIAL AND METHODS: In November-December 1998, a cross-sectional study was conducted among 255 children aged 8-10, who attended public schools in Sector 1 of the Oaxaca State Public Education Institute. Data were collected using the Frostig Evaluation of Visual Perception test and the equilibrium subscale of the Frostig Movement Skills Test Battery. A blood sample was taken to measure lead levels by atomic absorption spectrometry. Socioeconomic data and health histories were collected for use as control variables. Statistical analysis consisted of multiple regression models to test the relationship between blood lead level and the visual-motor and equilibrium tests. We assessed the efect of lead within the model using 1 000 Montecarlo simulations. RESULTS: The geometric mean of blood lead concentrations was 11.5 µg/dl (geometric standard deviation +6.3, -5.2. After adjusting for control variables, the visual-motor integration subscale was significantly related to blood lead concentration (p> 0.042. The visual-motor integration value decreased 1.78 (95% CI -3.51, -0.06 points for each 10 µg/dl increase in blood lead concentration. Among the four sub-tests comprising the visual-motor integration subscale, only eye-hand coordination (p=0.045 and spatial relations

  8. Eliminación del plomo por curado casero

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    Torres-Sánchez Luisa

    1999-01-01

    Full Text Available Objetivo. Evaluar el curado ácido como medida preventiva para reducir el contenido de plomo en vasijas de barro vidriadas. Material y métodos. En 27 vasijas de barro procedentes de cuatro estados de México se determinó, mediante espectrofotometría de absorción atómica, el nivel de plomo residual, después de cuatro lavados con ácido acético al 3%. Resultados. El contenido de plomo en el ácido acético utilizado para lavar las vasijas disminuyó proporcionalmente con el número de lavados, aunque se conservó por arriba de los niveles permisibles (2.5-7.0 p.p.m.. Conclusiones. El curado ácido de piezas de barro no es una medida preventiva útil para reducir la exposición a plomo.

  9. El plomo como contaminante alimentario

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    C. Rubio

    2004-01-01

    Full Text Available El plomo es un metal pesado caracterizado por ocasionar efectos tóxicos sobre el tracto gastrointestinal, sobre el sistema renal y sobre el SNC y periférico, así como interferencias con sistemas enzimáticos implicados en la síntesis del grupo hemo. A pesar de que en los últimos diez años, los contenidos de plomo de los productos alimenticios se han reducido sensiblemente gracias a los esfuerzos realizados para reducir la emisión de plomo en su origen y por los progresos en la garantía de calidad de los análisis químicos, la dieta sigue siendo una fuente importante de exposición de plomo. Es por ello que, el objetivo a largo plazo de las autoridades sanitarias es el de continuar reduciendo los contenidos medios de plomo en los productos alimenticios con el fin de que las ingestas medias dietéticas de Pb de las poblaciones cumplan con la PTWI (Provisional Tolerable Weekly Intake de 25 µg Pb/Kg/semana establecida por el Comité Mixto FAO/OMS

  10. Niveles de plomo elevados en sangre de niños que vivían en casas antiguas de Evansville, Indiana: asociación entre año de construcción de la casa, niveles de plomo en suelo y niveles de plomo en sangre de niños de 1-5 años, entre 1998-2006

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    Diane Jackson

    2012-08-01

    Full Text Available En este estudio se evaluaron los niveles de plomo en 18.218 muestras de sangre. Las muestras de 11.719 niños de Evansville, Indiana, de edades comprendidas entre 1 y 5 años se obtuvieron de manera voluntaria entre los años 1998 y 2006. Se evaluaron además los niveles de plomo en el suelo de 35 jardines residenciales correspondientes al domicilio de 81 niños.Durante el periodo de estudio, tanto los niveles de plomo en sangre como el porcentaje de valores elevados para dichos niveles fueron descendiendo. A pesar de ello, los valores de plomo en sangre en Evansville siguieron estando por encima de los nacionales (mediana de niveles de plomo en sangre 3,0 frente a 1,5 μg/dL, respectivamente. Nuestro análisis dio como resultado que vivir en casas antiguas (presumiblemente con pintura que contiene plomo estaba asociado con niveles más elevados de plomo en sangre en los niños. No se encontró una asociación clara de los niveles elevados de plomo en sangre ni con el género ni con los niveles de plomo en el suelo de los jardines.

  11. Experiencias de la instauración de normas relativas al contenido de plomo en aire y el agua, en los Estados Unidos de América Establishing lead in air and water standards in the United States of America

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    J Michael Davis

    2003-01-01

    Full Text Available En los Estados Unidos de América se ha logrado una disminución de la exposición a plomo de la población en general, gracias al establecimiento de diversas normas. En este artículo se destaca parte de los conocimientos adquiridos a través de la experiencia obtenida en este país en materia de plomo, en particular respecto al aire y al agua. Uno de los aspectos fundamentales es la posibilidad de contar con una base científica sólidamente establecida y claramente entendida, a partir de la cual se tomarán las medidas correspondientes. Los efectos secundarios de ciertas normas concernientes al aire ponen de manifiesto de qué manera los esfuerzos orientados a solucionar un problema pueden aportar beneficios en otras áreas, si bien pueden surgir consecuencias no deseadas, debido a la falta de previsión y de evaluación. Asimismo, en este documento se discuten las diferencias entre los enfoques centralizados y los descentralizados para el manejo de la exposición a plomo.Lead regulations and standards have resulted in a lower exposure to lead in the general population of the United States of America. This paper highlights some of the know-how developed through lead-containing experiences, particularly regarding lead content in air and water. The availability of a solid and clear scientific knowledge is central to the success of these policies. Collateral effects of some air-related standards show the extent to which problem-oriented efforts may be beneficial in other areas, inasmuch as they may have untoward consequences if careful planning and evaluation are not considered. Finally, this paper presents a discussion of the differences between centralized and decentralized approaches to lead exposure control.

  12. Neurotoxicidad de los metales pesados: plomo, mercurio, aluminio

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    Tostado Martín, Elena

    2014-01-01

    Este trabajo muestra las consecuencias para la salud en la población que sufre una exposición aguda o crónica a metales pesados. Más concretamente, se centra en la afectación del sistema nervioso central y su desarrollo tras la exposición al plomo, el mercurio y el aluminio. Esta revisión comienza con una breve introducción en la que se explica detalladamente las propiedades de cada metal pesado enunciado anteriormente, seguido de un breve repaso epidemiológico acerca de los pa...

  13. Evaluación de plomo en sangre de trabajadores de industrias de baterías

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    John J. Valbuena P.

    2011-03-01

    Full Text Available Se determinó el nivel de plomo y de protoporfirina de zinc en la sangre de trabajadores de tres pequeñas industrias dereciclaje y fabricación de baterías, ubicadas en Bogotá, Colombia, con el fin de establecer la existencia de riesgo ocupacional por la exposición a este elemento. También se realizó esta evaluación en personas no expuestas ocupacionalmente al plomo, para contribuir con el establecimiento de los valores base de plomo en la población colombiana no expuesta. Las muestras de sangre venosa fueron recolectadas en tubos de vidrio, libres de metales, con heparina. Se analizó el contenido de plomo por absorción atómica con horno de grafito y la protoporfirina de zinc por fluorescencia. be acuerdo con la legislación colombiana,los resultados indican que alrededor de un 31 % de los trabajadores de esestas industrias se encuentran en nivel deexposición peligrosa y de intoxicación; sin embargo, cuando los resultados se comparan con el valor de 30 ug Pb/dL desangre establecido por la American Conference Governmental Industrial Hygienists (ACGIH, el 91% de estos trabajadoressupera ese nivel, que es el valor de referencia adoptado por muchos países para la evaluación de riesgo ocupacionalpor exposición a plomo.

  14. Toxicidad y bioacumulación del plomo en Macrobrachium americanum

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    Reyes Chávez, Joaquín

    2014-01-01

    La evolución tecnológica ha hecho que el plomo (Pb) sea uno de los contaminantes antropogénicos más importante a nivel mundial al incorporarse fácilmente a los ciclos biogeoquímicos, resultando tóxicos para la biota y la salud humana. El plomo se considera un elemento no esencial y tóxico para las células, teniendo la capacidad para unirse al azufre de los aminoácidos y desplazar al Calcio (Ca+2). En este trabajo se propuso analizar y entender el proceso de acumulación y desintoxicación de pl...

  15. Cesión de plomo y otros metales desde las tuberías al agua de consumo en la Comunidad Autónoma del País Vasco Release of lead and other metals from piping into drinking water in the Basque Country (Spain

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    Itziar Zaldua Etxabe

    2010-12-01

    Full Text Available Objetivos: Valorar la exposición a plomo y otros metales relacionados con los materiales de las tuberías, a través del agua de consumo de las zonas de abastecimiento de la Comunidad Autónoma del País Vasco. Métodos: Muestreo aleatorio de viviendas en las zonas de abastecimiento. Se tomaron 3.295 muestras en 154 zonas que abastecían al 87% de las viviendas de los abastecimientos de nuestra comunidad. Se utilizó el método de muestreo conocido como random day time. En todas las muestras se determinó el plomo, y en las zonas de mayor población también el níquel, el cobre y el cromo. La determinación del hierro fue opcional. Resultados: El 1,75% (0,85-2,64 de las viviendas de las zonas de abastecimiento superaba el valor de referencia establecido para el plomo (10µg/l, el 2,21% (0,97-3,46 el del hierro (200µg/l y el 0,33% (0,11-0,55 el del níquel (20µg/l. Ninguna muestra superó los valores de referencia del cobre y el cromo (2mg/l y 50µg/l, respectivamente. Conclusiones: El problema de la cesión de metales desde las tuberías en las viviendas de la zonas estudiadas es residual. Las concentraciones de metales en el agua se encuentran, en la gran mayoría de las viviendas, por debajo de los valores de referencia, y no se considera necesario tomar medidas de carácter general. Los abastecedores deberán identificar la presencia de tuberías de plomo y su riesgo derivado en el programa de control y gestión de cada abastecimiento en particular, especialmente en aquellas zonas que no se han incluido o no han sido lo suficiente caracterizadas en este trabajo.Objectives: To evaluate exposure to lead and other metals from drinking water as a result of the materials used for pipes in the supply areas of the Basque Country (Spain. Method: Random sampling of properties in the supply areas was carried out. A total of 3,295 samples were taken in 154 areas, which together represented 87% of the properties supplied in our region. A method known

  16. Eliminación del plomo por curado casero Lead elimination by traditional acidic curing

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    Luisa Torres-Sánchez

    1999-11-01

    Full Text Available Objetivo. Evaluar el curado ácido como medida preventiva para reducir el contenido de plomo en vasijas de barro vidriadas. Material y métodos. En 27 vasijas de barro procedentes de cuatro estados de México se determinó, mediante espectrofotometría de absorción atómica, el nivel de plomo residual, después de cuatro lavados con ácido acético al 3%. Resultados. El contenido de plomo en el ácido acético utilizado para lavar las vasijas disminuyó proporcionalmente con el número de lavados, aunque se conservó por arriba de los niveles permisibles (2.5-7.0 p.p.m.. Conclusiones. El curado ácido de piezas de barro no es una medida preventiva útil para reducir la exposición a plomo.Objective. To evaluate traditional acidic curing as a preventive method for reducing lead content of glazed ceramic ware. Material and methods. In 27 ceramic ware pieces from four states in Mexico, the level of residual lead was determined through atomic absorption spectrophotometry after four washings with acetic acid 3%. Results. The lead content of the vinegar washing diminished proportionally with the number of washings, although it remained highly above the permissible levels of this metal (2.5-7.0 p.p.m.. Conclusions. Traditional acidic curing of glazed ceramic ware is not a useful preventive measure for reducing lead exposure.

  17. Intoxicación por munición de plomo en aves silvestres en España y medidas para reducir el riesgo

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    Mateo Soria, Rafael; Vallverdú Coll, Núria; Ortiz Santaliestra, Manuel Eloy

    2013-01-01

    La intoxicación por ingestión de munición de plomo en aves silvestres es conocida en España desde finales del siglo pasado. Elevadas densidades de perdigones de plomo en diversos humedales de importancia internacional producen tasas de ingestión de perdigones cercanas al 70% en especies como el ánade rabudo (Anas acuta) y el plumbismo llega a ser una de las principales causas de mortalidad de la amenazada malvasía cabeciblanca (Oxyura leucocephala). El plumbismo también ha sido descrito en di...

  18. Niveles de plomo en sangre y factores de exposición en niños del estado de Morelos, México

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    Meneses-González Fernando

    2003-01-01

    Full Text Available OBJETIVO: Evaluar los niveles de plomo en sangre de niños morelenses y sus factores de exposición. MATERIAL Y MÉTODOS: Estudio transversal para analizar, por voltametría anódica, los niveles de plomo en sangre de 232 niños de 1 a 12 años de edad, que acudieron de junio a octubre de 1996 al Hospital del Niño Morelense de Cuernavaca, Morelos, México. Los factores de exposición se indagaron por cuestionario. El valor de concentración de plomo se transformó al logaritmo natural; se estimó la razón de momios para algunos factores de exposición que se incorporaron a un modelo de ANOVA. RESULTADOS: Se reclutaron 232 niños (50% mujeres; 73% residentes en Cuernavaca. La media geométrica de plomo en sangre fue 6.7 µg/dl; 29.7% rebasaron los 10 µg/dl; 66% tenían antecedente de cocinar alimentos en barro vidriado; 36% de almacenar alimentos, y 19%, consumo de líquidos en ese material. CONCLUSIONES: Los niveles encontrados son similares a los reportados en otras poblaciones pediátricas mexicanas en los últimos años. Entre los principales factores de exposición destacan el uso de barro vidriado para consumo de alimentos o líquidos y la intensidad del tráfico donde viven. Este es el primer estudio que documenta los niveles de plomo en sangre en población infantil de Morelos, México, y sus resultados son punto de partida para acciones futuras de control y prevención.

  19. Exposición ocupacional a plomo inorgánico en una imprenta de la Ciudad de México

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    Aguilar-Madrid Guadalupe

    1999-01-01

    mbito de la exposición ocupacional al plomo no existen estudios publicados que permitan establecer niveles máximos permisibles tanto ambientales como biológicos. Por medio de este estudio se intenta contribuir al establecimiento de una normatividad de plomo en sangre, que actualmente está en discusión en México.

  20. Efectos del plomo en la salud de la niñez Effects of lead exposure on children's health

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    Thomas D Matte

    2003-01-01

    Full Text Available El plomo es un elemento que no tiene ninguna función fisiológica conocida en los seres humanos, pero cuyos efectos adversos inciden sobre una diversidad de procesos bioquímicos esenciales. Existe evidencia considerable acerca de los efectos adversos sobre la salud de los niños del plomo en niveles que son comunes a distintas poblaciones en todo el mundo. La intoxicación aguda por plomo, que ocasiona encefalopatía, a pesar de no ser frecuente, sí pone en riesgo la vida y requiere de un tratamiento agresivo y oportuno. Es necesario tenerla presente en el diagnóstico diferencial de toda enfermedad no explicada que incluya anemia, convulsiones, letargo, dolor abdominal, o vómito recurrente. Existe una gran cantidad de niños que padecen los efectos subclínicos crónicos debidos a la exposición de bajo nivel al plomo, y que incluyen un desarrollo cognitivo deficiente, trastornos en la conducta, ligera deficiencia en la agudeza auditiva, y talla reducida. La evidencia disponible indica que las únicas intervenciones efectivas para evitar la intoxicación de bajo nivel por plomo son aquellas que se aplican para controlar la exposición a este metal.Lead is an element that has no known physiologic function in humans but adversely affects a variety of fundamental biochemical processes. A large body of evidence shows adverse health effects of lead in children at levels common in populations around the world. Acute lead poisoning with encephalopathy, though infrequent, is life-threatening, requiring timely and aggressive treatment. It should be considered in the differential diagnosis of any unexplained illness that includes anemia, seizures, lethargy, abdominal pain, or recurrent vomiting. Many more children are harmed by chronic, subclinical effects of low-level lead exposure that include impaired cognitive development, adverse effects on behavior, subtle impairment of hearing acuity, and reduced height. Available evidence indicates that the

  1. Lake Chapala, Mexico: lead distribution in water, sediment and bacteria; Escenarios de la distribucion de plomo en agua, sedimentos y bacterias del lago de Chapala, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Anne M. [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico); Villa-Navia, Adriana [Interventor Ambiental de Occidental de Colombia, Inc. (Colombia); Afferden, Manfred van [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

    2006-04-15

    To evaluate the distribution of lead in the natural resources of lake Chapala, the adsorption of this metal in bacteria was analyzed and, through published data and the application of a chemical equilibrium model, the risk associated with the consumption of fish and water was estimated. Adsorption experiments of lead in three bacterial strains and simulations of the distribution of lead in the water-sediment-bacteria system indicate that the distribution of lead in the lake depends on variations of water quality such as suspended solids, lead and biomass concentrations. Considering only the lead contained in the bottom sediments, the simulations suggest that concentrations do not exceed the limits nor the criteria for use and protection of water, sediments, and biota. Considering an additional source of lead that locally increases the concentration by a factor of ten, the amount of lead in water and sediments may exceed these limits. The bioaccumulation of lead in lake Chapala was evaluated through calculation of bioconcentration and biomagnification factors, using simulated and published data on lead in fish (Ayla Jay y Ford, 2001). The results indicate that lead may be concentrated 721 and 6,195 times in bacteria and fish, respectively. Furthermore, bioaccumulation of lead in the lake may occur mainly as bioconcentration in fish rather than biomagnification in the food chain. [Spanish] Para evaluar la distribucion de plomo en los recursos naturales en el lago de Chapala se analizo la adsorcion de este metal en bacterias y, mediante datos publicados en la literatura y modelacion numerica, se estimo el riesgo asociado al consumo de peces y agua. Experimentos de adsorcion en tres cepas de bacterias y simulaciones de la distribucion en un sistema agua-sedimentos-bacterias indican que la distribucion del plomo en el lago depende de variaciones en calidad del agua tales como solidos suspendidos totales, plomo total y biomasa. Considerando unicamente el plomo contenido

  2. Efecto del fotoperiodo en la remoción de plomo por Lemna gibba L. (Lemnaceae

    Directory of Open Access Journals (Sweden)

    Guadalupe Miranda

    2015-08-01

    Full Text Available El plomo llega a las aguas provenientes de las industrias de baterías, soldaduras, pinturas, etc. causando daños a los seres vivos, por lo que es necesario promover el desarrollo de tecnologías que ayuden a mejorar la calidad de los efluentes y que al mismo tiempo sean adecuadas al contexto socioeconómico del país. En este trabajo se plantea el uso de una angiosperma acuática, la especieLemna gibbade la familia Lemnaceae que tiene un crecimiento exponencial y su cultivo es fácil en laboratorio. Para absorber el plomo (PbNO32 se prepararon cinco concentraciones, a nivel de bioensayo en el laboratorio y bajo el efecto de dos diferentes condiciones de fotoperiodo (luz continua y 12 h luz/12 h oscuridad durante cuatro días, ya que a partir de este día libera el Pb al medio. Los resultados indican que en las dos concentraciones de Pb más bajas (30 y 50 mgl-1, el fotoperiodo 12/12 es más favorable para su absorción (9405 µgl-1más y 18,895 µgl-1 más respectivamente mientras que en las tres restantes (100, 200 y 300 mgl-1 lo fue la condición de luz continua. (6600 µgl-1, 1949 µgl-1, 5587 µgl-1 más respectivamente. Los conocimientos que se derivan de este estudio, permiten optimizar el uso deL. gibbaen el tratamiento terciario de aguas residuales.

  3. Evaluación de los niveles de contaminación por plomo en el aire, a partir de las muestras obtenidas en las estaciones de monitoreo de la calidad del aire en la ciudad de Bogotá

    Directory of Open Access Journals (Sweden)

    Eduardo O. Ojeda B.

    2011-06-01

    Full Text Available La presente investigación es requisito parcial para optar al título de Magister Scientiae en Ambiental. El propósito es la determinación del contenido de plomo en las muestras de material en forma de partículas, obtenidas en las trece estaciones que conforman la Red-Bogotá.

  4. Orientation relationship of eutectoid FeAl and FeAl2

    Science.gov (United States)

    Scherf, A.; Kauffmann, A.; Kauffmann-Weiss, S.; Scherer, T.; Li, X.; Stein, F.; Heilmaier, M.

    2016-01-01

    Fe–Al alloys in the aluminium range of 55–65 at.% exhibit a lamellar microstructure of B2-ordered FeAl and triclinic FeAl2, which is caused by a eutectoid decomposition of the high-temperature Fe5Al8 phase, the so-called ∊ phase. The orientation relationship of FeAl and FeAl2 has previously been studied by Bastin et al. [J. Cryst. Growth (1978 ▸), 43, 745] and Hirata et al. [Philos. Mag. Lett. (2008 ▸), 88, 491]. Since both results are based on different crystallographic data regarding FeAl2, the data are re-evaluated with respect to a recent re-determination of the FeAl2 phase provided by Chumak et al. [Acta Cryst. (2010 ▸), C66, i87]. It is found that both orientation relationships match subsequent to a rotation operation of 180° about a 〈112〉 crystallographic axis of FeAl or by applying the inversion symmetry of the FeAl2 crystal structure as suggested by the Chumak data set. Experimental evidence for the validity of the previously determined orientation relationships was found in as-cast fully lamellar material (random texture) as well as directionally solidified material (∼〈110〉FeAl || solidification direction) by means of orientation imaging microscopy and global texture measurements. In addition, a preferential interface between FeAl and FeAl2 was identified by means of trace analyses using cross sectioning with a focused ion beam. On the basis of these habit planes the orientation relationship between the two phases can be described by (01)FeAl || (114) and [111]FeAl || [10]. There is no evidence for twinning within FeAl lamellae or alternating orientations of FeAl lamellae. Based on the determined orientation and interface data, an atomistic model of the structure relationship of Fe5Al8, FeAl and FeAl2 in the vicinity of the eutectoid decomposition is derived. This model is analysed with respect to the strain which has to be accommodated at the interface of FeAl and FeAl2. PMID:27047304

  5. Determining lead sources in Mexico using the lead isotope ratio La identificación de fuentes de exposición a plomo en México a través de la determinación de la razón de isótopos de plomo

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    Madhu Chaudhary-Webb

    2003-01-01

    plasma inductivamente acoplado (ICP-MS Perkin Elmer 5000, en interfase con un sistema de vaporización electrotérmica (ETV Perkin Elmer HGA-600MS. RESULTADOS: Las razones de isótopos (206Pb/204Pb, 207Pb/204Pb, y 208Pb/204Pb, tanto de los especímenes de sangre, como de los de cerámica se correlacionaron fuertemente, con valores de r² de 0.9958, 0.9915, y 0.9890, para las tres razones de isótopos, respectivamente, sugiriendo que la exposición a plomo probablemente se debió al uso de la cerámica. Las mediciones de las razones de isótopos de plomo de la gasolina con plomo, que todavía se usaba al momento de la toma de muestras de sangre, fueron distintas de las encontradas en sangre y en cerámica. CONCLUSIONES: La determinación de las razones de isótopos de plomo puede ser una herramienta eficiente para la identificación de las fuentes principales de exposición a plomo y para apoyar la implantación de medidas de salud pública para prevención y control.

  6. (phoenicopterus roseus por intoxicación aguda por plomo

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    D Romero

    2007-01-01

    Full Text Available La presencia de plomo en el medio ambiente es un hecho indiscutible. Ello es objeto de gran interés sanitario pues repercute tanto en la salud de los animales como en la del ser humano. El plumbismo es una intoxicación que puede afectar a cualquier especie animal. En el ámbito de la fauna silvestre se asocia principalmente a la actividad cinegética en los humedales y a la ingestión de plomo metálico por parte de las aves que frecuentan estos ecosistemas. En España cada año mueren decenas de miles de aves acuáticas como consecuencia de la ingesta de perdigones de plomo. En los individuos capturados enfermos se pueden observar signos clínicos, mientras que a partir de muestras de cadáveres se obtienen datos sobre niveles tisulares de plomo. Sin embargo la evaluación de lesiones anatomopatológicas en animales de vida silvestre es difícil de realizar por la dificultad de encontrar animales recién muertos o afectados de un cuadro agudo mortal. La reproducción de esta patología en animales de experimentación se suele realizar en cisnes, palomas o patos, pero no en flamencos, por lo que no es usual disponer de datos histológicos en esta especie. En este trabajo presentamos la clínica, analítica y estudio microscópico de diferentes tejidos de un flamenco común (Phoenicopterus roseus muerto por plumbismo.

  7. El entorno de los plomos: historiografía y linaje

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    García-Arenal, Mercedes

    2003-12-01

    Full Text Available The aim of this article is to propose new ideas concerning the authorship of the Lead Tablets from the Sacromonte, locating them, on the one hand, in the political context of the years in which they were forged, and on the other, in connection with the genealogical and historiographic works that were produced in the same period. This study proposes that the Lead Tablets were inserted into these historiographical and genealogical literature in response to their polemical nature, by making use of both History and the Arabic language as a means for ennobling Arab descent, principally by presenting the main Spanish heroes of the moment, the Christian martyrs, as Arabs. This particular use of History favours the noble lineages of the Grenadine new converts, and must have been encouraged or supported by members of those lineages. The thesis of this article is that the most likely involved in the Lead forgeries is the family Granada Venegas. This thesis is supported by showing the connections between the affair of the Lead Tablets with various members of the literary society that used to meet at the home of don Alonso Granada Venegas.

    Este artículo intenta aportar nuevas ideas acerca de la autoría de los Plomos del Sacromonte y de sus objetivos poniéndolos, por un lado, en el contexto político de los años en los que fueron realizados y por otro en conexión con la historiografía y la escritura genealógica que se producen en ese mismo período. Propone que los Plomos, una fabricación morisca, se insertan en esa producción escrita, que tiene un cariz polémico al que intenta dar respuesta por medio de ennoblecer el origen árabe y la lengua árabe, presentando como árabes a los máximos héroes cristianos del momento, es decir, los mártires. Dicha escritura tiene el fin principal de favorecer a los linajes moros de Granada en un momento en que sus privilegios se veían amenazados e incluso arriesgaban ser expulsados. Debió de ser por

  8. Niveles de plomo en sangre en niños de 8 a 10 años y su relación con la alteración en el sistema visomotor y del equilibrio

    Directory of Open Access Journals (Sweden)

    Azcona-Cruz María Isabel

    2000-01-01

    equilibrio. CONCLUSIONES: La relación negativa entre el plomo y la habilidad visomotora concuerda con los resultados encontrados en niños en otros países. Al parecer las concentraciones de plomo en sangre, que son comunes en los niños de Oaxaca, son suficientes para ocasionar una limitación visomotora de naturaleza sutil. Los resultados de este estudio señalan la necesidad de reforzar la iniciativa de reducir la exposición de los niños a las fuentes de exposición conocidas, en especial barro vidriado y, por lo tanto, reducir los niveles poblacionales de plomo en sangre.

  9. Efectos de la exposicion a bajas concentraciones de plomo en ratones sobre diferentes parametros bioquimicos

    Directory of Open Access Journals (Sweden)

    N. Martínez Riera

    2001-01-01

    Full Text Available Las bases moleculares que explicarían los efectos de la exposición crónica a bajos niveles de plomo sobre diferentes procesos bioquímicos, no se encuentran bien esclarecidos aun. Varios estudios sugieren que el plomo (Pb2+ induce alteraciones en diversos parámetros bioquímicos y hematológicos. Este estudio se realizó con el objeto de determinar los efectos de exposición de ratones a bajas concentraciones de Pb2+ sobre las siguientes variables: glucosa plasmática (GP, colesterol total (CT, triglicéridos (TG, hematocrito (Hto y tiempo de transformación de fibrinógeno en fibrina (TF. Se estudiaron 20 ratones adultos de la cepa C3H (40-50g de peso. Los animales fueron mantenidos en ambientes con temperatura (24°C y humedad (50 % constantes, con ciclos de luz/oscuridad de 12 hs. Fueron alimentados con una dieta estándar libre de Pb2+ y agua ad - libitum. A un grupo de ratones (n=10, se les agregó en el agua de bebida, acetato de plomo en una concentración de 1 ppm (grupo expuesto, manteniendo los 10 ratones restantes como grupo control. Luego de un periodo de 6 meses en estas condiciones, se extrajeron muestras de sangre de los animales incluidos en este estudio para dosar GP, CT, TG, Hto, y TF, como variables metabólicas y hematológicas, y los niveles de actividad del ácido delta-aminolevulínico sintetasa (ALA D como marcador principal de exposición al plomo. La exposición de ratones a 1 ppm durante 6 meses, resultó en cambios significativos en la mayoría de las variables analizadas en el grupo expuesto con respecto al grupo control, como lo muestran los siguientes resultados: GP g/l(2.18 ± 0.53 v.s. 1.18 ± 0.2 (P<0,0001, CT g/l (2.07 ± 0.29 v.s. 1.86 ± 0.27 (P<0.05; TF sg (12.41 ± 1.37 v.s. 15.9 ± 2.43 (P<0.0003;. Hto % (45.55.± 4.8 v.s. 41.77 ± 2.1 (P<0.02; ALA-D U/l (10.22 ± 2.8 v.s. 17.07 ± 1.1 (P<0.0001. Los niveles de TG no mostraron diferencias significativas entre ambos grupos.

  10. Nachhaltigkeit als Impulsgeber für ein Relationship Marketing

    OpenAIRE

    Stephanie Friedrichs

    2005-01-01

    In einem Umfeld hoher Wettbewerbsintensität und zunehmender Sättigungstendenzen auf vielen Märkten gestaltet sich die Neukunden-Akquisition für Unternehmen immer aufwedniger und kostenintensiver. Die als Konzeptwechesl diskutierte Abkehr von Transaktions-Marketing hin zu einer Gestaltung langfristiger Anbieter-Nachfrager-Beziehungen gilt als zukünftige Entwicklungsrichtung für das Relationship Marketing. Der Beitrag diskutiert die Möglichkeiten und Grenzen der Nachhaltigkeitsrationalität hier...

  11. Juan Bautista Pérez and the Plomos de Granada: Spanish Humanism in the Late Sixteenth Century

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    Ehlers, Benjamin

    2003-12-01

    Full Text Available This article addresses the Parecer of the humanist Juan Bautista Pérez (d. 1597, one of the earliest critics of the relics unearthed in Granada in the decade after 1588. Given his relatively progressive morisco policy as bishop of Segorbe, Pérez might well have welcomed the plomos, which created a history that encompassed both Muslims and Christians. His humanist training, however, led him to conclude that the plomos were a modem forgery, and that their veneration would lead the Spanish people astray. The Parecer (1595 of Pérez represents one example of scholarly rigor, creativity, and religious devotion among Spanish humanists in the later sixteenth century.

    Este trabajo examina el parecer del obispo y humanista Juan Bautista Pérez (ca. 1534-1597, uno de los primeros críticos de las reliquias desenterradas en Granada a partir de 1588. Dada su política morisca bastante progresista en la diócesis de Segorbe, bien habría podido Pérez aprobar la aparición de los plomos, que creaban una historia común para cristianos y musulmanes. Su erudición, por el contrario, le hizo concluir que los plomos fueron una fabricación moderna, y que su veneración pondría en peligro de desviación religiosa al pueblo español. El parecer de Pérez (1595 es un ejemplo de rigor, creatividad, y devoción religiosa entre los humanistas de finales del siglo XVI.

  12. Niveles de plomo en sangre en niños de 8 a 10 años y su relación con la alteración en el sistema visomotor y del equilibrio Relationship of blood lead levels with visual-motor and equilibrium disturbances in children aged 8 to 10 years

    OpenAIRE

    María Isabel Azcona-Cruz; Rothenberg, Stephen J.; Lourdes Schnaas-Arrieta; Manuel Romero-Placeres; Estela Perroni-Hernández

    2000-01-01

    OBJETIVO: Identificar si existe una asociación negativa entre los niveles de plomo en sangre y la coordinación visomotora y el equilibrio de escolares. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en 255 niños de 8 a 10 años de edad, que asistían a escuelas del Sector 1 del Instituto de Educación Pública del Estado de Oaxaca, durante noviembre y diciembre de 1998. Se les aplicaron las pruebas de evaluación de la percepción visual de Frostig y la subescala de equilibrio Frostig Moveme...

  13. Exposición ocupacional a plomo y pesticidas órganofosforados: efecto sobre la salud reproductiva masculina

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    Sandra Yucra

    2008-10-01

    Full Text Available Actualmente, la exposición ocupacional a contaminantes como metales pesados y plaguicidas ha crecido por la actividad industrial, minera y agrícola. Los efectos adversos en la salud humana se presentan en el sistema respiratorio, renal, nervioso, endocrino, reproductor, siendo este último muy sensible a muchos agentes físicos y químicos generados por la actividad industrial o agrícola. Estos agentes están presentes en algunas actividades ocupacionales y en el ambiente en general. Las evidencias de estudios toxicológicos, epidemiológicos, bioquímicos y fisiológicos, demuestran que el plomo tiene efectos adversos en la salud humana de los trabajadores ocupacionalmente expuestos a diferentes concentraciones pudiendo causar infertilidad masculina. El impacto de la exposición crónica al plomo en el varón incluye reducción de la libido, alteración en la espermatogénesis (reducción en cantidad y motilidad, e incremento de formas anormales de los espermatozoides, daño cromosómico, función prostática anormal y cambios en los niveles de testosterona. Para el caso de los plaguicidas órganofosforados (OP hay un alto riesgo de exposición ocupacional y no ocupacional de estos químicos debido a su extenso uso en la agricultura y en el ambiente doméstico, se ha demostrado, que afectan también el sistema reproductor masculino actuando como tóxicos testiculares que causan alteraciones citotóxicas y citocinéticas reversibles en las células germinales, alteran la síntesis de andrógenos y la calidad seminal en los trabajadores expuestos a OP, sobre todo los individuos dedicados a la actividad agrícola. En la presente revisión se ha recopilado diferente información de los efectos adversos de la exposición ocupacional al plomo y a los plaguicidas órganofosforados sobre la función reproductiva.

  14. ¿Es el plomo empleado en deportes (caza, tiro y pesca deportiva un problema de salud pública infravalorado?

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    Raimon Guitart

    2005-01-01

    Full Text Available La munición y los pesos empleados en actividades recreativas como la caza, el tiro y la pesca deportiva han sido fabricados tradicionalmente con plomo. En España la caza y el tiro son responsables de la dispersión en la naturaleza de cerca de 6.000 toneladas anuales del metal pesado, mientras que podemos estimar en 100 las aportadas por pescadores deportivos a las zonas acuáticas. Las pocas medidas legales que varios países han adoptado en contra del uso del plomo en esos deportes se han basado en las pruebas irrefutables que indicaban que cada año fallecían intoxicadas millones de aves, que ingerían inadvertidamente esos pequeños objetos de plomo hallados abandonados en sus hábitats naturales. En este trabajo se discute si el enfoque conservacionista que se ha dado hasta ahora al problema resulta adecuado, y si las evidencias de los daños sobre los seres humanos son o no suficientes para extender todavía más esas medidas de prohibición, en especial teniendo en cuenta que en niños se considera que no hay dosis de exposición segura. Se concluye que en algunos aspectos los datos ya existen, aunque en otros los estudios tóxico-epidemiológicos son todavía escasos, sugiriendo que al tema se le ha prestado poca atención. En cualquier caso, resulta preocupante constatar que el principio de precaución no se ha aplicado para solucionar un problema cuyos efectos sanitarios serán más a largo plazo que inmediatos.

  15. Plomo en la sangre del cordón umbilical y su impacto sobre el peso, longitud, hemoglobina y APGAR en zonas con diferente grado de contaminación

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    J. Castro Bedriñana

    2012-01-01

    Full Text Available En el presente estudio se ha evaluado la concentración de plomo en la sangre del cordón umbilical de 64 neonatos nacidos de mujeres gestantes que viven en las ciudades de Huancayo (zona urbana-comercial y La Oroya (zona metalúrgica del Centro del Perú y su impacto sobre el nivel de hemoglobina, longitud, peso y APGAR al nacimiento. El estudio transversal se realizó en los Hospitales II de EsSalud de La Oroya y Hospital Regional de Huancayo entre noviembre del 2003 a abril del 2004, cuando la fundición de la Oroya estaba en normal funcionamiento. La cuantificación del plomo se realizó por espectrometría de absorción atómica con horno de grafito en el Instituto Peruano de Energía Nuclear. El muestreo biológico respondio a los protocolos de Iyengar y Rapp. Los neonatos de Huancayo y la Oroya tuvieron concentraciones promedio de plomo de 18,03ug/dLy 22,96 ug/dL(p=0,016, siendo estos valores 1,8 y 2,3 veces más altos que el nivel crítico sugerido por la CDC y la WHO (10ug/dL. Los niveles de hemoglobina para los neonatos de Huancayo y La Oroya fueron 18,3 y 16,9g/dL (p=0,000. Solo se registraron cuadros de anemia en los neonatos de la Oroya (9,38%. Al análisis de regresión, fue evidente la asociación inversa entre el contenido de plomo en la sangre del cordón umbilical y el contenido de hemoglobina, peso, logitud y puntaje APGAR al nacimiento.

  16. Manejo de la intoxicación por plomo en la niñez

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    Markowitz Morri E

    2003-01-01

    Full Text Available El presente artículo hace una revisión del manejo clínico de la intoxicación por plomo en la niñez. Se menciona las definiciones de las diferentes técnicas de medición usadas para la determinación de plomo, y se destacan sus ventajas y posibles limitaciones. La medición de los niveles de plomo sanguíneo puede realizarse utilizando muestra de sangre anticoagulada por espectrofotometría de absorción atómica voltametría anódica. Sin embargo, un método más eficiente para medir las concentraciones de plomo en hueso es mediante fluorescencia de Rayos X o para la determinación sistémica en un nivel bioquímico una técnica adecuada es la determinación de los niveles de plomo en orina. El tratamiento incluye la eliminación de la fuente de exposición, cambios en los hábitos de los niños y una dieta adecuada en calcio y hierro. La quelación con edetato de calcio y succimer elimina el plomo del esqueleto, el cual es eliminado por riñón; puede salvar vidas cuando la intoxicación es importante, y existe una reducción a corto plazo seguida de un aumento subsecuente de los niveles de plomo sanguíneo. En casos graves suele requerirse de dosis repetidas. La terapia de quelación puede ser necesaria en casos de niveles de plomo sanguíneo por arriba de 45 µg/dl. La quelación reduce los niveles de plomo sanguíneo y los síntomas asociados, sin embargo, la disminución cognoscitiva puede ser irreversible, por lo que la utilización de medidas preventivas es mucho mejor que las de curación.

  17. Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyong June [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule of mixtures. A quantitative relationship between UTS and deformation true strain was determined. X-ray diffraction data on transformation of Al + Ca microstructures to Al + various Al-Ca intermetallic compounds were obtained at the Advanced Photon Source at Argonne National Laboratory. Electrical conductivity was measured over a range of true strains and post-deformation heat treatment schedules.

  18. Acumulación de plomo en hueso y sus efectos en la salud

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    Sanín Luz Helena

    1998-01-01

    Full Text Available Los efectos nocivos del plomo han sido conocidos desde tiempos antiguos por su amplia gama; este metal afecta prácticamente todos los órganos y sistemas del cuerpo humano. Recientemente se han documentado efectos tóxicos crónicos en los sistemas cardiovascular y nervioso, con niveles que antes se consideraban seguros. El sitio primario de almacenamiento de plomo en el organismo es el hueso, pero sólo hasta fechas recientes se ha clarificado la significancia toxicológica de este hecho. En este artículo se analiza el papel del plomo en hueso como fuente de exposición endógena, como biomarcador de exposición crónica y como tejido blanco. Se presentan además los avances recientes para la medición de plomo en hueso mediante los rayos X-fluorescentes (XRF. Finalmente se revisa la importancia, para la salud pública, de estudiar y medir el plomo en hueso en lugares con una historia de exposición crónica como la Ciudad de México y en los ambientes ocupacionales, especialmente como fuente remanente de exposición. Se analiza especialmente el caso de mujeres en edad reproductiva, quienes pueden convertirse en fuentes de exposición para el feto y para el niño amamantado.

  19. Contenido de plomo y cadmio en aceites de girasol

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    López Martínez, M. C.

    2001-08-01

    Full Text Available We have studied the lead and cadmium content in 21 samples of sunflower oil from Andalucía (Southern Spain. These elements are toxicological importance and the sunflower oil is widely consumed in Spain. Samples were mineralized with nitric acid and vanadium pentoxide as catalyst, and ana lyzed using electrothermal atomization atomic absorption spectroscopy. The temperature-time programme for the graphite furnace was optimized for each element, and the accuracy, precision, sensitivity and detection limit of the method were evaluated. Concentrations of lead ranged from not detectable to 167.58 μg/kg and cadmium concentrations ranged from 0.87 to 8.30 μg/kg. The data obtained are not excessive and similar to those mentioned by other authors; however, one sample of the total analyzed surpassed the limit of 0.1 ppm of lead proposed by the Spanish and European Legislation. A statistical significative correlation has been established between Pb and Cd levels (p Se ha determinado el contenido de plomo y cadmio en 21 muestras de aceite de girasol, todas ellas producidas en Andalucía (Sur de España. Ambos elementos tienen una gran importancia toxicológica y el aceite de girasol es muy consumido en España. Las muestras han sido mineralizadas con ácido nítrico, utilizando pentóxido de vanadio como catalizador, y analizadas mediante espectroscopia de absorción atómica con atomización electrotérmica. Se ha optimizado el programa temperatura-tiempo del horno de grafito para cada elemento y se ha evaluado la exactitud, precisión, sensibilidad y límite de detección del método. Las concentraciones de plomo han oscilado entre no detectables y 167.58 μg/kg y las concentraciones de cadmio entre 0.87 y 8.30 μg/kg. Estos datos no resultan excesivos y concuerdan con los aportados por otros autores; no obstante, una de las muestras analizadas supera el límite máximo de 0.1 ppm de Pb establecido en las Legislaciones Española y Europea. Se

  20. Niveles de plomo en sangre de niños expuestos a los residuos metalúrgicos en Abra Pampa, Jujuy (Argentina

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    JA Tschambler

    2015-01-01

    Full Text Available Abra Pampa es una pequeña comunidad situada en el norte de Argentina, donde los desechos de plomo de una planta metalúrgica (Metal H uasi se abandonaron por más de 40 años, dejándolos en el centro del pueblo. Con el fin de medir la expo sición a estos residuos peligrosos, se determinaron los niveles de plo mo en sangre en niños de edades comprendidas entre 5 y 14 años (n=234 . Los niños incluidos en la muestra habían estado expuestos, por el aire y el suelo, al plomo durante cinco años por lo menos porqu e vivían alrededor de la montaña de residuos. Fueron evaluados clínicamente. Para determinar el estado nutricional se midió el peso y talla y se calculó el índice de masa corporal total. Se reali zó el análisis de plombemia mediante la técnica de Espectrofotometría de Absorción Atómica-atomización electrotérmica. La prevalencia d e intoxicación (Pb> 10 μg / dL fue de 28%. El 81% de los niños estudiados tenían niveles de plomo en sangre superiores a 5 μg / dL, lo que se considera un riesgo en el desarrollo neuromadurativo. También se encontraron diferenc ias significativa s según la edad y la distancia entre las casas de los niños y el sitio de disposició n de los residuos. Estos resultados mos traron que los residuos son una fuente de exposición al plomo para los niños que viven cerca del depós ito de escorias y generaron estrategias de remediación para minimiz ar la exposición infantil.

  1. Manejo de la intoxicación por plomo en la niñez

    OpenAIRE

    Markowitz Morri E

    2003-01-01

    El presente artículo hace una revisión del manejo clínico de la intoxicación por plomo en la niñez. Se menciona las definiciones de las diferentes técnicas de medición usadas para la determinación de plomo, y se destacan sus ventajas y posibles limitaciones. La medición de los niveles de plomo sanguíneo puede realizarse utilizando muestra de sangre anticoagulada por espectrofotometría de absorción atómica voltametría anódica. Sin embargo, un método más eficiente para medir las concentraciones...

  2. Evaluacion de las alteraciones conductuales y dopaminergicas en ratones con bajas concentraciones de plomo.

    OpenAIRE

    N. Martínez Riera; M.J. Gandur; Soria, N.; N. Riera de Martínez Villa

    2001-01-01

    La investigación de los efectos del plomo en animales de experimentación y sus consecuencias en el desarrollo neurológico conductual es compleja y controvertida. Conociendo que la maduración neurológica de los ratones ha culminado en edades que oscilan entre los 25-35 días, nuestro objetivo ha sido investigar si la administración de soluciones de diferentes concentraciones de plomo, durante tiempos establecidos de acuerdo a las dosis-ingesta, producía alteraciones en los ...

  3. Intervención ambiental en sitios contaminados por plomo: la experiencia en los Estados Unidos de América

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    Ceto Nicholas

    2003-01-01

    Full Text Available Durante una década, los organismos estatales y federales han trabajado de manera conjunta con las comunidades a lo largo del territorio estadounidense, con el objeto de valorar el riesgo a la salud que implica la contaminación por plomo en las zonas residenciales. A menudo dichas comunidades han estado vinculadas con instalaciones destinadas anteriormente a actividades como la minería y la metalurgia; sin embargo, existen otras industrias como por ejemplo la fabricación de pinturas y el reciclaje de baterías, también identificadas como fuentes de contaminación por este metal. La vasta experiencia en las tareas de limpieza de los sitios contaminados ha puesto de manifiesto que los amplios programas destinados a identificar y manejar las vías de exposición pueden ayudar, de manera efectiva, a disminuir los niveles de plomo en sangre de las poblaciones más suceptibles, como la de los de niños en edades tempranas. Los programas de intervención ambiental son más efectivos cuando en las localidades afectadas se ejecutan programas de educación/intervención en salud, orientados al desarrollo de estrategias individualizadas para manejar el riesgo que implica la presencia de dicho metal en el ambiente.

  4. RELATIONSHIPS BETWEEN HYDROGEN AND MICROSTRUCTURAL FEATURES OF AL ALLOYS

    OpenAIRE

    Chernyayeva, O.; Lisovytskiy, D.

    2008-01-01

    The distribution of hydrogen between the different states was estimated from hydrogen permeation and hydrogen extraction measurements and was correlated with the microstructure features of Al-Mg-Mn, Al-Mg-Mn-Fe and Al-Zn-Mg-Mn-Fe alloys. Hydrogen lattice diffusivity was found to depend on the mean free paths between the main phase precipitate complexes. The content of reversibly trapped hydrogen correlated with the volume fraction of precipitates

  5. Niveles sanguíneos de plomo en neonatos hijos de madres consumidoras de "basuco": estudio comparativo

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    Martha Piedad Restrepo

    1988-02-01

    Full Text Available

    Obtention of cocaine clorhydrate from coca leaves requires the use of gasoline; therefore residues such as lead may remain in the base paste (basuca; the latter is smoked, under the name basuco, mixed with tobacco or marijuana; It is conceivable that the smoker takes up lead residues that Increase lead blood levels; we wanted to determine whether the use of basuco during pregnancy could produce such effect In the newborn infant. Serum lead concentrations were measured In 19 newborn children and In 18 of their mothers. The latter were basuco consumers. They were compared to those of 20 non consuming delivering women along with 19 of their newborn Infants. Measurements were performed on a Perkin-Palmer model 2380 atomic absorption

    spectrophotometer. Women were divided in four groups according to the degree of consumption, as follows: mild, moderate, Intense or non existent. Mean levels and SDs in the children were respectively: 13.5 ± 9.4; 15.8 ± 6.5; 16.6 ± 7.8; 6.9 ± 5.0 ug/dl; and In their mothers: 13.3 ± 4.6; 13.5 ± 6.9; 16.2 ± 4.9; 8.4 ± 4.6 ug/dl Statistic analysis revealed highly significant differences between mothers and children exposed to basuco and those that were not exposed. No difference was observed ac. cording to the degree of consumption. In conclusion: newborn from basuco consuming mothers have Increased lead blood levels; the long term effects of such alteration should be the subject of further studies.

    La obtención del clorhidrato de cocaína a partir de la hoja de coca requiere el uso de gasolina; residuos de ésta pueden permanecer en la pasta base (basuca; al fumar ésta, mezclada con cigarrillo o marihuana (basuco el consumidor puede captar residuos de plomo e Incrementar sus concentraciones sanguíneas del mismo; quisimos saber si el uso del basuco

  6. Lead exposure among young urban women Exposición a plomo en mujeres jóvenes residentes en zonas urbanas

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    Jacqueline M. Moline

    1999-11-01

    estudio de cohorte. Material y métodos. Las mujeres elegibles fueron aquellas que acudieron al centro de salud de la ciudad de Nueva York durante 1995-1998, tenían entre 18 y 25 años de edad y estaban sanas. El reclutamiento se llevó a cabo por los proveedores de salud, el coordinador del estudio y las mismas mujeres. Se administraron cuestionarios detallados y se obtuvieron muestras sanguíneas en donde se determinaron los niveles de plomo en sangre total, ferritina y hematocrito. Resultados. A la fecha se han reclutado 239 mujeres. La población es predominantemente de grupos minoritarios: 62% africanas-americanas, 33% hispánicas y 5% caucásicas-asiáticas. El promedio de edad es de 19.3 años. El reclutamiento de las participantes se hace invitando a las mujeres que previamente han aceptado participar en el estudio (55%. Algunas se enteraron del estudio por los proveedores de salud. El nivel medio de plomo fue de 2.1±1.7 µg/dl, el cual es consistente con las encuestas nacionales más recientes de Estados Unidos. Conclusiones. Los niveles de plomo en sangre son bajos en mujeres de grupos minoritarios, jóvenes, en edad reproductiva, que residen en zonas urbanas de la ciudad de Nueva York. En esta población el reclutamiento se incrementó sustancialmente con la ayuda de las participantes y la comunidad de proveedores de salud.

  7. Efectos en la calidad espermática del ciervo de la exposición a plomo y otros metales pesados: aplicación de modelos de exposición in vitro con espermatozoides.

    OpenAIRE

    Castellanos Expósito, Pilar

    2014-01-01

    El plomo (Pb) uno de los tóxicos ambientales e industriales más difundidos en el planeta debido al uso con muy variados fines que se ha hecho de este metal por diferentes civilizaciones a lo largo de la historia, lo que explica la intensa actividad de extracción minera de Pb que se ha tenido que asegurar cantidades suficientes de este metal. En lo que a nuestro país se refiere, la comarca minera del Valle de Alcudia y Sierra Madrona durante los siglos XX y XX se encontraba a la cabeza de pr...

  8. Niveles de plomo sanguíneo en recién nacidos de La Oroya, 2004-2005

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    Godofredo Pebe

    2008-10-01

    Full Text Available Objetivo. Determinar los niveles de plomo en sangre de los recién nacidos (RN de menos de 12 horas de vida, en la ciudad de La Oroya. Material y métodos. Estudio descriptivo, transversal y prospectivo realizado entre junio de 2004 a junio de 2005 de una muestra de recién nacidos (RN de La Oroya, se usó un cuestionario para la madre gestante y se determinó los niveles de plomo en sangre venosa (2 mL utilizando la espectrofotometría por absorción atómica con llama de aire de acetileno. Los valores se expresan en microgramos de plomo por decilitro de sangre (μg/dL. Resultados. Se evaluσ 93 RN; el nivel promedio de plomo en sangre fue de 8,84 ± 0,57 μg/dL. El 75,3% (70/ RN tuvo niveles de plomo en sangre entre 6 a 10 μg/dL, y 24,7% (23 RN tuvo mαs de 10 μg/dL. Los RN de madres que viven en La Oroya Nueva tienen menos niveles de plomo que los que viven en La Oroya Antigua (p=0,002. Conclusiones. Los RN de la ciudad de La Oroya presentan elevados niveles de plomo en sangre, por lo que se requiere iniciar programas de prevención en las madres gestantes para evitar futuros daños a la salud de los recién nacidos.

  9. Estudio sobre la incorporación y retención de plomo en zeolita natural

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    Abraham Mendoza Córdoba

    2014-12-01

    Full Text Available Las zeolitas son un grupo de minerales que corresponden a la clase de los silicatos (tectosilicatos, entre las diversas utilidades que tienen estos minerales está la resolución de problemas ambientales, particularmente en la eliminación de contaminantes, entre estos se encuentran los metales pesados, los cuales están presentes en los suelos de zonas industriales, en el agua potable, en los afluentes de aguas procedentes de la industria y de la actividad minera, o bien procedentes de mantos acuíferos. Su utilidad se debe en parte por tener una gran capacidad de intercambio iónico, así como también por tener una estructura con cavidades de dimensiones nanométricas, eso le da la capacidad de incorporar elementos ajenos al mineral dentro de dichas cavidades. En el presente trabajo se ha experimentado con Pb incorporándolo en zeolitas (chabazita como acetato de plomo (Pb(CH3COO2 3H2O con el fin de conocer, por una parte, la capacidad del mineral para alojar dicho metal después de activarla, y por otra parte, conocer la capacidad de retención del metal después de un proceso reversible a la incorporación de Pb (activación.

  10. Niveles de plomo en gestantes y neonatos en la ciudad de la Oroya, Perú

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    Jorge Castro-Bedriñana

    2013-07-01

    Full Text Available Objetivos. Determinar los niveles de plomo (Pb en gestantes y neonatos en la ciudad de La Oroya, Perú. Materiales y métodos. Se realizó un estudio transversal. La población estuvo conformada por gestantes residentes durante al menos dos años en la ciudad de La Oroya, cuando operaban normalmente las fundiciones de Pb, cobre y zinc. Se obtuvo muestras de sangre de la gestante antes del parto y luego del parto se tomaron muestras de placenta y sangre del cordón umbilical. El nivel de Pb de dichas muestras fue evaluado por espectrometría de absorción atómica con horno de grafito. Se determinaron regresiones cuadráticas y correlaciones de Pearson. Resultados. Se evaluó cuarenta partos normales. Los niveles promedio de Pb en la sangre materna, cordon umbilical y placenta fueron 27,4 ± 15,6 ug/dL; 19,0 ± 12,6 ug/dL y 319,0 ± 215,9 ug/100 g, respectivamente. El 67,5% de los neonatos tuvieron más de 10 ug/dL de Pb. El nivel de Pb de la sangre del cordón umbilical representó el 69,4% del nivel de Pb en sangre materna. Los coeficientes de correlación entre el Pb de la sangre materna y cordón umbilical, sangre materna y placenta, placenta y sangre del cordón umbilical fueron 0,36; 0,48 y 0,33, respectivamente. Conclusiones. Cuando funcionaba la fundición, las gestantes y recién nacidos tenían concentraciones elevadas de Pb en sangre. Las concentraciones de Pb en la placenta y cordón umbilical tuvieron una correlación moderada con el Pb de la sangre materna. El Pb de la sangre materna y cordón umbilical fue 1,5 veces más alto que los de zonas más alejadas

  11. Niveles de plomo en gestantes y neonatos en la ciudad de la Oroya, Perú

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    Jorge Castro-Bedriñana

    2013-09-01

    Full Text Available Objetivos. Determinar los niveles de plomo (Pb en gestantes y neonatos en la ciudad de La Oroya, Perú. Materiales y métodos. Se realizó un estudio transversal. La población estuvo conformada por gestantes residentes durante al menos dos años en la ciudad de La Oroya, cuando operaban normalmente las fundiciones de Pb, cobre y zinc. Se obtuvo muestras de sangre de la gestante antes del parto y luego del parto se tomaron muestras de placenta y sangre del cordón umbilical. El nivel de Pb de dichas muestras fue evaluado por espectrometría de absorción atómica con horno de grafito. Se determinaron regresiones cuadráticas y correlaciones de Pearson. Resultados. Se evaluó cuarenta partos normales. Los niveles promedio de Pb en la sangre materna, cordon umbilical y placenta fueron 27,4 ± 15,6 ug/dL; 19,0 ± 12,6 ug/dL y 319,0 ± 215,9 ug/100 g, respectivamente. El 67,5% de los neonatos tuvieron más de 10 ug/dL de Pb. El nivel de Pb de la sangre del cordón umbilical representó el 69,4% del nivel de Pb en sangre materna. Los coeficientes de correlación entre el Pb de la sangre materna y cordón umbilical, sangre materna y placenta, placenta y sangre del cordón umbilical fueron 0,36; 0,48 y 0,33, respectivamente. Conclusiones. Cuando funcionaba la fundición, las gestantes y recién nacidos tenían concentraciones elevadas de Pb en sangre. Las concentraciones de Pb en la placenta y cordón umbilical tuvieron una correlación moderada con el Pb de la sangre materna. El Pb de la sangre materna y cordón umbilical fue 1,5 veces más alto que los de zonas más alejadas

  12. Asociación entre plomo en sangre y parámetros sociodemográficos en población infantil Association between blood lead and sociodemographic parameters among children

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    Maritza Rojas

    2003-08-01

    Full Text Available OBJETIVO: Establecer la relación entre concentración de plomo en sangre (Pb-S y parámetros demográficos y socioeconómicos, en una población infantil. METODOS: Se estableció la relación entre la concentración de plomo en sangre (Pb-S, de 243 niños (promedio de edad 5,94±2,78 años, que asistieron al Centro de Investigaciones Toxicológicas de la Universidad de Carabobo (CITUC, Venezuela (periodo 1998-2000. Se utilizó tecnología de Sistemas Geográficos de Información (SGI, ubicando espacialmente a los niños, asociando de forma gráfica la procedencia de éstos con los resultados analíticos. RESULTADOS: El promedio de Pb-S de la población total (11,62 ug/dl, fue significativamente superior al límite permisible (CDC=10 ug/dl. El número de niños con valores superiores al límite permisible de Pb-S (VSLP [150; 61,7%], fue significativamente alto (pOBJECTIVE: To determine the relationship between blood lead concentration (Pb-S, and sociodemographic parameters among children. METHODS: Blood lead concentration (Pb-S was determined in 243 children (aged 5.94±2.78 years in the district of Valencia. The required analysis was performed at the Center for Toxicological Investigations of University of Carabobo (CITUC, Venezuela, between January 1st, 1998 to December 31st, 2000. Geographical Information Systems (GIS technology was used for data mapping. RESULTS: Average Pb-S (11.62 ug/dl was significantly higher than the allowed levels. One hundred and fifty (61.7% children had Pb-S levels above the allowed concentration (VSLP and this amount was significantly high in relation to the total number of subjects studied. The logistic regression analysis showed a significant association of sectors 12 (status A and 16 and 28 (status C with VSLP (R=0.1189; p<0,01; R=0.1202, p<0,01 and R=0.1189; p<0.01, respectively. Odds ratio showed that children from status C are 7,286 times more likely to have Pb-S VSLP than those from A or B. CONCLUSIONS: This

  13. Estudios de bioadsorción de plomo por Saccharomyces cereviceae en soluciones acuosas

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    Juan José Pauro Roque

    2009-06-01

    Full Text Available Studies of lead biosorption by Saccharomyces cereviceae in aqueous solutionsResumen: El ecosistema del lago Titicaca (Puno, Perú y sus tributarios, viene siendo perturbado por metales pesados producto de la actividad minera emergente. Para controlar y reducir la contaminación existen procesos biológicos llevados a cabo por microorganismos como las levaduras (biorremediación. Este trabajo de investigación tiene como objetivos evaluar la capacidad de bioadsorción de plomo mediante  Saccharomyces cereviceae en soluciones acuosas y la influencia de dos niveles de pH durante la bioadsorción. Para esto se ensayaron dos concentraciones de S. cereviceae (cel/mL, las cuales fueron cuantificadas por un hemocitómetro y luego traspasadas a una solución con concentraciones conocidas de plomo (5 y 25 mg/L. Se realizaron lecturas de las concentraciones de plomo a los 5, 60 y 120 minutos. La mayor capacidad de bioadsorción resultó cuando S. cereviceae estaba a una concentración de 5 x 106 cel/mL, y el pH óptimo fue de 5,14. Se concluye que S. cereviceae constituye una buena alternativa para la bioadsorción de plomo, quedando abierta su validación en condiciones de campo en el altiplano peruano.Palabras clave: bioadsorción, plomo, levadura. Abstract:  Lake Titicaca’s ecosystem and that of its tributaries in Puno (Peru are being disturbed by heavy metals resulting from emergent mineral activity. Biological processes involving microorganisms such as yeasts (bioremediation are being used for controlling and reducing such pollution. This research was aimed at evaluating Saccharomyces cereviceae’s lead biosorption capacity in aqueous solutions and evaluating the influence of two pH levels on biosorption. Two S. cereviceae concentrations (cel/mL were tested; these concentrations were quantified in a haemocytometer and then put into a solution having a known lead concentration (5 and 25 mg/L. Lead concentrations were read after 5, 60

  14. Exposición ocupacional a plomo inorgánico en una imprenta de la Ciudad de México Occupational exposure to inorganic lead in a printing plant in Mexico City

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    Guadalupe Aguilar-Madrid

    1999-01-01

    mbito de la exposición ocupacional al plomo no existen estudios publicados que permitan establecer niveles máximos permisibles tanto ambientales como biológicos. Por medio de este estudio se intenta contribuir al establecimiento de una normatividad de plomo en sangre, que actualmente está en discusión en México.Objective. To describe occupational lead exposure and its biological indicators in workers in a printing company. Material and methods. An epidemiological and industrial hygiene research was undertaken. Lead was measured in the air of work environment and on the hands of the participants; additionally, subjects underwent a venous blood samples for the determination of whole blood lead by atomic absorption spectrophotometry; and a bone lead measurement using a spot-source 109Cd K-X-ray fluorescence instrument. Also, a standardized questionnaire was applied. We obtained information on demographic and life styles factors, work history, type of work, position and activity within the company. Results. Of the 209 workers, 117 agreed to participate and 90 (83.3% males and 16.7% females completed all phases of the study. The average lead concentrations were: in air samples, of 0.94 mg/m³; in hands before washing, of 6 802 mg/m²; in hands after washing, of 194 mg/m²; in whole blood, of 12.3 mg/dl; and in tibia and fibula, of 25.9 and 43.3 mg Pb/g of bone mineral, respectively. Important variations in these measurements were observed according to the workers post. Conclusions. Worldwide, lead exposure levels have been used to evaluate acute exposures being in the workplace. The higher lead levels find in the bone of the workers in this study are similar to other occupational studies in the United States of America and suggest that the accumulated metal in bone may be an important endogenous exposure source, and here its measurement importance. However in developing countries because its high costs per application, the measurements in bone lead become limited to

  15. Manejo de la intoxicación por plomo en la niñez Managing childhood lead poisoning

    OpenAIRE

    Morri E Markowitz

    2003-01-01

    El presente artículo hace una revisión del manejo clínico de la intoxicación por plomo en la niñez. Se menciona las definiciones de las diferentes técnicas de medición usadas para la determinación de plomo, y se destacan sus ventajas y posibles limitaciones. La medición de los niveles de plomo sanguíneo puede realizarse utilizando muestra de sangre anticoagulada por espectrofotometría de absorción atómica voltametría anódica. Sin embargo, un método más eficiente para medir las concentraciones...

  16. Relationship between solid fraction and distribution of Pb in Al-Pb ingot

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The influence of solid fraction of Al-28Pb alloy mushy on distribution of Pb in Al-Pb ingot was studied. The special electromagnetic stirring apparatus was used to prepare Al-28Pb alloy mushy and the relationship between solid fraction and stirring temperature was gotten. The results show that when solid fraction of Al-28Pb alloy mushy is less than 45%, Pb precipitation usually happens in the ingot. However, Pb precipitation in casting reduces gradually with increasing solid fraction of mushy, and when solid fraction is larger than 45%, Pb precipitation in casting can be removed.

  17. Asociación entre plomo en sangre y parámetros sociodemográficos en población infantil

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    Maritza Rojas

    2003-08-01

    Full Text Available OBJETIVO: Establecer la relación entre concentración de plomo en sangre (Pb-S y parámetros demográficos y socioeconómicos, en una población infantil. METODOS: Se estableció la relación entre la concentración de plomo en sangre (Pb-S, de 243 niños (promedio de edad 5,94±2,78 años, que asistieron al Centro de Investigaciones Toxicológicas de la Universidad de Carabobo (CITUC, Venezuela (periodo 1998-2000. Se utilizó tecnología de Sistemas Geográficos de Información (SGI, ubicando espacialmente a los niños, asociando de forma gráfica la procedencia de éstos con los resultados analíticos. RESULTADOS: El promedio de Pb-S de la población total (11,62 ug/dl, fue significativamente superior al límite permisible (CDC=10 ug/dl. El número de niños con valores superiores al límite permisible de Pb-S (VSLP [150; 61,7%], fue significativamente alto (p<0,01 con respecto a la población total. Al asociar mediante regresión logística, la frecuencia de niños con VSLP con los sectores de procedencia, se demostró que los sectores 12, 16 y 28 presentaron correlaciones parciales directas significativas (R=0,1189; p<0,01; R=0,1202, p<0,01 y R=0,1189; p<0,01 respectivamente. Al asociar la frecuencia de niños con VSLP y su categorización socioeconómica, el análisis de regresión logística reveló que para los niños con VSLP, la probabilidad de pertenecer a la categorización C se incrementa en un factor de 7.286. CONCLUSIÓNS: El estudio confirma que la utilización de SGI y métodos epidemiológico-estadísticos, extiende las posibilidades de prevención de enfermedades producidas por contaminantes como el Pb y que correlacionando datos geográficos y de salud, se pueden identificar áreas de "alto riesgo", conduciendo a una acción pro-activa de salud pública.

  18. Evaluacion de las alteraciones conductuales y dopaminergicas en ratones con bajas concentraciones de plomo.

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    N. Martínez Riera

    2001-01-01

    Full Text Available La investigación de los efectos del plomo en animales de experimentación y sus consecuencias en el desarrollo neurológico conductual es compleja y controvertida. Conociendo que la maduración neurológica de los ratones ha culminado en edades que oscilan entre los 25-35 días, nuestro objetivo ha sido investigar si la administración de soluciones de diferentes concentraciones de plomo, durante tiempos establecidos de acuerdo a las dosis-ingesta, producía alteraciones en los juegos solitarios en animales de experimentación adultos. Se trabajó con ratones adultos de ambos sexos de la cepa C3H, alimentados con dieta estándar y agua ad libitum. Se utilizaron seis lotes: tres experimentales que fueron tratados con acetato de plomo en el agua de bebida en diferentes concentraciones: 1, 1000 y 2000 ppm y en los tres grupos controles, la ingesta fue de agua potable. En este trabajo se estudiaron los juegos solitarios de los animales: 1 Actividad locomotora, 2 Aseo total, 3 Exploración subterránea (en tiempo y frecuencia y 4 Exploración aérea total. Se determinó el nivel de dopamina presente en el cerebro de los mismos por espectrofluorometría. Los resultados obtenidos de las alteraciones conductuales en los animales de experimentación analizados con tests no paramétricos fueron: disminución significativa de la actividad locomotora (número de cuadros, de la exploración subterránea (en tiempo, de la exploración aérea (en tiempo y del aseo total, no observándose variaciones significativas en la exploración subterránea (en frecuencia. Las variables investigadas estarían mediadas por distintos sistemas de neurotrasmisión. En la dopamina determinada en cerebro de ratones con ingesta de plomo de 1 - 1000 - 2000 ppm se encontró disminución significativa de la misma en los ratones tratados con respecto a los grupos controles.

  19. Tendencia de los niveles de plomo en la atmósfera de la zona metropolitana de la Ciudad de México: 1988-1998

    Directory of Open Access Journals (Sweden)

    Cortez-Lugo Marlene

    2003-01-01

    Full Text Available OBJETIVO: Describir las tendencias del plomo atmosférico asociadas a la eliminación paulatina del plomo de la gasolina y el uso de convertidores catalíticos en el auto transporte de la Ciudad de México, de 1988 a 1998. MATERIAL Y MÉTODOS: Estudio de series de tiempo que incluye las mediciones atmosféricas de plomo que se obtuvieron, entre 1988 y 1998, de nueve estaciones de la red manual de monitoreo atmosférico de la Ciudad de México. Las intervenciones evaluadas fueron la introducción de gasolina Magnasin, el uso de convertidores catalíticos y el descenso en la concentración de plomo hasta su eliminación total de la gasolina utilizada en los auto transportes. Se describen las tendencias de plomo por monitor, por zona geográfica, utilizando un modelo de regresión que incorpora una estructura de auto-correlación. RESULTADOS: La introducción de gasolina sin plomo y de los convertidores catalíticos se asoció con un descenso en la concentración de plomo atmosférico en 23%, la reducción paulatina del plomo en la gasolina ocasionó una reducción acumulada de 89% en todas las zonas estudiadas. CONCLUSIONES: La introducción de la gasolina sin plomo ha logrado abatir las concentraciones ambientales de este contaminante de una manera importante.

  20. Orientation relationships of Laves phase and NiAl particles in an AFA stainless steel

    Science.gov (United States)

    Trotter, Geneva; Baker, Ian

    2015-12-01

    The alumina-forming austenitic (AFA) stainless steel, Fe-20Cr-30Ni-2Nb-5Al (in at. %) was solutionized at 1250 °C in order to obtain a fully austenitic microstructure and then aged for up to 1325 h at 800 °C to precipitate the Laves phase and B2-NiAl particles typically found in AFAs. This paper describes detailed analyses of the orientation relationships between these particles and the matrix which were determined by transmission electron microscopy. Four variants of the (1 1 1)m//(0 0 0 1)p, ?m//? orientation relationship proposed by Denham and Silcock (J. Iron Steel Inst. 207 (1969) p.582) were observed for the Laves phase, and six variants of the (1 1 1)m//(0 1 1)p, ?m//? Kurdjumov-Sachs relationship were observed for the B2-NiAl phase.

  1. Relationship Between the Processing Parameters and the Properties of Semi-solid Processed Al Alloys

    Institute of Scientific and Technical Information of China (English)

    SangYullee; BomSokKin; SangYonglee; HanJunglee

    2001-01-01

    Relationship between the processing parameters and the properties of semi-solid processed Al alloys were studied and microstructure and mechanical properties of semi-solid processed Al parts for automobile application as a function of processing parameters were compared with those of die-cast parts and forged parts. In addition, the locations for the gate during the semi-solid processing were varied to elucidate the distribution of micro-porosities and resulting mechanical properties and the T6 heat tre...

  2. Remoción de plomo en soluciones acuosas empleando nanoaluminofosfatos amorfos

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    Wendy Rondón

    2015-01-01

    Full Text Available Se emplearon nanopartículas de aluminofosfatos amorfos entre 23 a 30 nm de diámetro para la adsorción de iones plomo (Pb2+ en soluciones acuosas. Los materiales fueron sintetizados mediante biosíntesis utilizando como plantillas biológicas las células de levadura Saccharomyces cerevisiae. Los estudios de adsorción se llevaron a cabo empleando el método batch, utilizando 100 mg del sólido nanométrico y 200 µg L-1 de iones plomo. La determinación cuantitativa de Pb+2 fue realizada mediante espectrometría de absorción atómica con atomización electrotérmica (EAA-HG. Los valores obtenidos para el porcentaje de remoción (% EF, capacidad de adsorción qe (µg g-1 y coeficiente de remoción Kd (mL g -1 fueron de 40; 90 y 800 en promedio, respectivamente. Los resultados obtenidos demostraron las potencialidades que presentan estos materiales para la adsorción de iones Pb2+, siendo excelentes candidatos para la remediación de aguas contaminadas.

  3. Relationship between silver concentration with microstructural and mechanical properties of rolled AlZn alloy

    International Nuclear Information System (INIS)

    The relationship of Ag addition on microstructural and mechanical properties of rolled AlZn alloy was investigated. AlZn alloys were prepared by metal mould casting method and the Ag addition was done by Vortex technique. Microstructural characterization of AlZnAg specimens was analyzed by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Results show that the phases of the as-cast state alloy are solid solution zinc-rich hexagonal close-packed (hcp) crystal structure, named η-phase and α-Al solid solution with Zn dissolved into the matrix. The silver concentration in AlZn alloy influences the volume of AgZn3 precipitates. The mechanical properties, especially the flow stress and elongation of the alloy were improved by the Ag addition. The Vortex method was used in order to diminish the process cost, generating an alloy with homogenous microstructure, less casting porosity and better mechanical properties.

  4. Estudio de la evolución de la exposición a plomo en la población infantil española en los últimos 20 años: ¿Un ejemplo no reconocido de «salud en todas las políticas»? Trend in lead exposure in the Spanish child population in the last 20 years: An unrecognized example of health in all policies?

    Directory of Open Access Journals (Sweden)

    Sabrina Llop

    2013-04-01

    Full Text Available Objetivo: Describir la evolución temporal de las concentraciones de plomo en el aire en España, desde antes de su prohibición como aditivo de la gasolina hasta la actualidad, así como estudiar la evolución de la carga corporal de plomo en la población infantil española. Métodos: Se obtuvieron las concentraciones medias anuales de plomo en el aire en diversas ciudades españolas, desde la década de 1980 hasta la actualidad. Se realizó una búsqueda bibliográfica con el fin de identificar estudios publicados sobre concentraciones de plomo en la población infantil española. Resultados: En general se observó una disminución de las concentraciones de plomo, de mayor magnitud entre 1991 y 1999. Esta evolución decreciente se asocia con una disminución de las concentraciones de plomo en la población infantil española, desde 1989 (año en que se publica el primer estudio sobre exposición infantil al plomo hasta hoy. La disminución, tanto en el aire como en la población infantil, es muy probable que sea consecuencia de las medidas legislativas que han regulado la cantidad máxima de plomo en la gasolina, desde 1987 hasta su prohibición total en agosto de 2001. Conclusiones: Desde el punto de vista de la salud pública, la prohibición del uso de gasolina con plomo fue una acción que aumentó la protección de la salud de la población española.Objective: To describe the time trend in atmospheric lead concentrations in Spain, from before lead was banned as a gasoline additive to the present, and to determine the trend in lead body burden in the Spanish child population. Methods: We obtained the annual average for atmospheric lead levels in several Spanish cities from the 1980s to the present. A literature search was conducted to identify published studies on lead concentrations in populations of Spanish children. Results: Overall, atmospheric lead levels decreased, particularly between 1991 and 1999. This downward trend was related

  5. Niveles de plomo en sangre y factores de exposición en niños del estado de Morelos, México Blood lead levels and exposure factors in children of Morelos State, Mexico

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    Fernando Meneses-González

    2003-01-01

    Full Text Available OBJETIVO: Evaluar los niveles de plomo en sangre de niños morelenses y sus factores de exposición. MATERIAL Y MÉTODOS: Estudio transversal para analizar, por voltametría anódica, los niveles de plomo en sangre de 232 niños de 1 a 12 años de edad, que acudieron de junio a octubre de 1996 al Hospital del Niño Morelense de Cuernavaca, Morelos, México. Los factores de exposición se indagaron por cuestionario. El valor de concentración de plomo se transformó al logaritmo natural; se estimó la razón de momios para algunos factores de exposición que se incorporaron a un modelo de ANOVA. RESULTADOS: Se reclutaron 232 niños (50% mujeres; 73% residentes en Cuernavaca. La media geométrica de plomo en sangre fue 6.7 µg/dl; 29.7% rebasaron los 10 µg/dl; 66% tenían antecedente de cocinar alimentos en barro vidriado; 36% de almacenar alimentos, y 19%, consumo de líquidos en ese material. CONCLUSIONES: Los niveles encontrados son similares a los reportados en otras poblaciones pediátricas mexicanas en los últimos años. Entre los principales factores de exposición destacan el uso de barro vidriado para consumo de alimentos o líquidos y la intensidad del tráfico donde viven. Este es el primer estudio que documenta los niveles de plomo en sangre en población infantil de Morelos, México, y sus resultados son punto de partida para acciones futuras de control y prevención.OBJECTIVE: To assess blood lead levels and lead exposure factors in children living in Morelos State, Mexico. MATERIAL AND METHODS: A cross-sectional study was conducted between June and October 1996, in 232 children aged 1-12 years, at Hospital del Niño Morelense de Cuernavaca, Morelos, Mexico. Blood lead levels were measured by anodic voltameter, and exposure factors were collected by questionnaire. The lead concentration value was log transformed for statistical analysis. Odds ratios were obtained for some risk factors. The statistical significative risk factors

  6. Niveles de plomo elevados en sangre de niños que vivían en casas antiguas de Evansville, Indiana: asociación entre año de construcción de la casa, niveles de plomo en suelo y niveles de plomo en sangre de niños de 1-5 años, entre 1998-2006 Higher blood lead levels among children living in older homes in Evansville Indiana: associations between year house built, soil lead levels and blood lead levels among children aged 1-5 years - 1998 to 2006 Elevados níveis de chumbo no sangue de crianças que vivem em habitações antigas em Evansville, Indiana: associação entre o ano de construção da casa, níveis de chumbo no solo e níveis de chumbo no sangue de crianças de 1-5 anos, entre 1998 - 2006

    Directory of Open Access Journals (Sweden)

    Diane Jackson

    2012-08-01

    Full Text Available En este estudio se evaluaron los niveles de plomo en 18.218 muestras de sangre. Las muestras de 11.719 niños de Evansville, Indiana, de edades comprendidas entre 1 y 5 años se obtuvieron de manera voluntaria entre los años 1998 y 2006. Se evaluaron además los niveles de plomo en el suelo de 35 jardines residenciales correspondientes al domicilio de 81 niños.Durante el periodo de estudio, tanto los niveles de plomo en sangre como el porcentaje de valores elevados para dichos niveles fueron descendiendo. A pesar de ello, los valores de plomo en sangre en Evansville siguieron estando por encima de los nacionales (mediana de niveles de plomo en sangre 3,0 frente a 1,5 μg/dL, respectivamente. Nuestro análisis dio como resultado que vivir en casas antiguas (presumiblemente con pintura que contiene plomo estaba asociado con niveles más elevados de plomo en sangre en los niños. No se encontró una asociación clara de los niveles elevados de plomo en sangre ni con el género ni con los niveles de plomo en el suelo de los jardines.A total of 18,218 blood lead levels (BLLs were assessed. The samples from 11,719 children aged 1-5 years in Evansville, Indiana, were obtained on a volunteer basis between 1998 and 2006. In addition, soil lead levels were also evaluated from 35 residential yards that were matched to the addresses of 81 children.During the study period, both average BLLs and the percentage of elevated BLLs declined. Even so, Evansville’s BLLs still remained higher than national levels (median BLLs of 3.0 vs.1.5 μg/dL, respectively. From our analysis, living in older houses (presumably containing lead paint was associated with higher BLLs in children. No clear association was found between higher BLLs and gender or residential soil lead levels.Neste estudo avaliaram-se os níveis de chumbo em 18.218 amostra de sangue. As amostras de 11.719 crianças de Evansville, Indiana, de idades compreendidas entre 1 e 5 anos obtiveram-se de forma

  7. Investigación epidemiológica sobre niveles de plomo en la población infantil y en el medio ambiente domiciliario de Ciudad Juárez, Chihuahua, en relación con una fundición de El Paso, Texas Epidemiologic study of lead levels in children and in the household environment in Ciudad Juárez, Chihuahua, México, and an area near a foundry in El Paso, Texas, USA

    Directory of Open Access Journals (Sweden)

    Blanca Raquel Ordóñez

    2003-01-01

    Full Text Available Se estudió una muestra representativa de los hogares de Ciudad Juárez y el 100% de los situados al noroeste de esa ciudad, cercanos a la fundición de El Paso, Texas, a determinar niveles de plomo en sangre por lo menos un niño de 1 a 9 años de edad de cada hogar, así como el plomo del polvo intradomiciliario y de la tierra de patios, jardines de la misma casa. Se estudió riesgo ocupacional y el de ingestión de plomo por uso de loza. Se encontró que los niveles de plomo en sangre eran mayores en los niños cuyos hogares se encontraban más próximos a la fundición. Hubo una correlación positiva entre niveles de plomo en sangre y el contenido del metal en el polvo intradomiciliario y en la tierra de sus patios o jardines, estos hechos no influyeron el riesgo ocupacional ni el uso de utensilios de loza que desprendieran plomo.A representative overall sampling of households in Ciudad Juárez, plus 100 per cent of the households in an area northwest of that city near a foundry in El Paso, Texas, were studied to determine the bloodlead level of at least one child within the 1-to-9 year age range in each home and the lead content of the dust inside the house and the dirt on its yard or grounds. The occupational risk was studied, as was the risk of lead intake from food prepared in enamel cooking utensils. Bloodlead levels were found to be highest in children whose homes were closest to the foundry. There was a positive correlation between bloodlead levels and the lead content of the dust in the home and the dirt in its yard or grounds. No association was established between the higher lead levels and occupational hazards or the use of enamel cooking utensils that give of lead.

  8. Niveles de plomo sanguíneo en madres y recién nacidos derechohabientes del Instituto Mexicano del Seguro Social

    Directory of Open Access Journals (Sweden)

    Navarrete-Espinosa Joel

    2000-01-01

    Full Text Available OBJETIVO: Establecer la relación entre el nivel de plomo sanguíneo materno (PSM y el de sangre en cordón umbilical (PSC al momento del parto, así como determinar los principales predictores del PSM en derechohabientes del Instituto Mexicano del Seguro Social (IMSS, en el Distrito Federal (D.F.. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en el que se reclutaron voluntarias con embarazo normoevolutivo y se les tomaron muestras de sangre al momento del parto, en cuatro hospitales del IMSS en el D.F., de 1991 a 1993. Se tomó, además, muestra de sangre de cordón umbilical. Los datos fueron analizados mediante regresión lineal simple y múltiple. RESULTADOS: Se estudiaron un total de 1 404 binomios madre-hijo; el promedio de edad de las madres fue de 25 años. La media de PSM fue 10.7 ± 6.5 µg/dl; no se encontraron variaciones significativas por hospital, edad o estado civil. Para el PSC la media fue de 10.4 ± 6.2 µg/dl. Por cada aumento en una unidad logarítmica de PSM, el PSC aumenta 0.62 (p<0.01 unidades logarítmicas. La correlación entre ambos fue de 0.61 (p<0.01. Los principales predictores de PSM fueron el uso de loza vidriada, el consumo de leche y jugo de naranja, estos últimos se asociaron inversamente con el PSM. Un 47% de las madres y 50% de los niños tuvieron valores superiores a 10 µg/dl. En 578 recién nacidos se registraron niveles de plomo superiores a los de la madre. CONCLUSIONES: Se sugiere continuar la línea de investigación para proponer tipos de intervención.

  9. Manejo de la intoxicación por plomo en la niñez Managing childhood lead poisoning

    Directory of Open Access Journals (Sweden)

    Morri E Markowitz

    2003-01-01

    Full Text Available El presente artículo hace una revisión del manejo clínico de la intoxicación por plomo en la niñez. Se menciona las definiciones de las diferentes técnicas de medición usadas para la determinación de plomo, y se destacan sus ventajas y posibles limitaciones. La medición de los niveles de plomo sanguíneo puede realizarse utilizando muestra de sangre anticoagulada por espectrofotometría de absorción atómica voltametría anódica. Sin embargo, un método más eficiente para medir las concentraciones de plomo en hueso es mediante fluorescencia de Rayos X o para la determinación sistémica en un nivel bioquímico una técnica adecuada es la determinación de los niveles de plomo en orina. El tratamiento incluye la eliminación de la fuente de exposición, cambios en los hábitos de los niños y una dieta adecuada en calcio y hierro. La quelación con edetato de calcio y succimer elimina el plomo del esqueleto, el cual es eliminado por riñón; puede salvar vidas cuando la intoxicación es importante, y existe una reducción a corto plazo seguida de un aumento subsecuente de los niveles de plomo sanguíneo. En casos graves suele requerirse de dosis repetidas. La terapia de quelación puede ser necesaria en casos de niveles de plomo sanguíneo por arriba de 45 µg/dl. La quelación reduce los niveles de plomo sanguíneo y los síntomas asociados, sin embargo, la disminución cognoscitiva puede ser irreversible, por lo que la utilización de medidas preventivas es mucho mejor que las de curación.This paper reviews the clinical management of children with lead poisoning. A first step is to define the measures to be used in their assessment and be aware of the limitations. Measurements of blood lead levels can be made on anti-coagulated whole blood samples using either: atomic absorption spectroscopy or anodic stripping voltametry. However a more accurate method is fluorescent RX'ray of the skeleton or systematic biochemical tests of lead

  10. Humoral immune alterations caused by lead: studies on an adult toad model Alteraciones inmunes humorales causadas por plomo: estudios en un modelo de sapo adulto

    Directory of Open Access Journals (Sweden)

    Carolina E. Rosenberg

    2007-07-01

    (heteroaglutininas naturales fueron también cuantificados contra EO. Ambas evaluaciones fueron llevadas a cabo empleando un método de ELISA desarrollado a este fin, midiendo la absorbancia (A. Para los anticuerpos anti-EO naturales, tanto en sapos controles (C como en sapos tratados con Pb (T, hubo una tendencia significativa a incrementar las absorbancias iniciales (C inicial: 0,69±0,39 A; T inicial: 0,54±0,30 A; la relación T/C tampoco mostró cambios. La única diferencia significativa se encontró entre las muestras inicial y final de los sapos tratados con plomo (p<0,014. Los niveles de anticuerpos anti-EO inmune de sapos inmunizados con EO mostraron un bajo incremento significativo (p<0,05 en los animales tratados con plomo (T final: 0,66±0,36 A, al compararse con sapos control (C final: 0,91±0,50 A al final del experimento. De este modo, se concluye que los cambios debidos a las dosis analizadas de Pb en los niveles de anticuerpos no pueden explicarse sólo sobre la base de un único mecanismo de acción del metal, sino como resultado de una conjunción de efectos sobre diferentes subpoblaciones de células inmunocompetentes. Estas diferentes respuestas sugieren que los factores que afectan los animales expuestos a un estímulo externo son diferentes de aquellos que influyen la respuesta en los animales silvestres.

  11. Cuantificación de plomo, cadmio y cromo mediante sialoquímica

    Directory of Open Access Journals (Sweden)

    GONZÁLEZ MIREYA

    1997-01-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, p<= 0.05; gamma = -0.5224, p<= 0.05. Conclusiones. La sialoquímica juega un papel importante en la detección de contaminantes, fármacos, drogas y enfermedades locales y sistémicas. La contaminación por metales pesados sigue siendo un problema de salud pública, por lo que el gobierno debe consolidar un programa cuyo objetivo sea eliminar los diferentes contaminantes del ambiente. Asimismo, se deben realizar otros estudios para verificar la asociación de variables como sexo, edad, uso de cerámica vidriada, alimentación y zona de residencia con las concentraciones de metales pesados en saliva.

  12. ANÁLISIS DE ALEACIONES POR QUELATOMETRIA PARTE UNO ALEACIONES CON COBRE, PLOMO Y CINC

    Directory of Open Access Journals (Sweden)

    Alfonso Clavijo Diaz

    2010-09-01

    Full Text Available Se desarrolla un modelo químico-matemático con fundamento en los equilibrios ácido-base y asistido por un computador personal, para el análisis de iones metálicos aislados o en mezclas. Se elaboran curvas de titulación teóricas teniendo en cuenta el quelón, el pH, las especies formadoras de complejos (auxiliares y enmascarantes y el uso de un indicador metalocrómico. Como resultado de lo anterior, se desarrolla un método de análisis volumétrico (quelatometría para la determinación cuantitativa de los iones cobre, plomo y cinc en aleaciones.

  13. Análisis de aleaciones por quelatometria. Parte uno: aleaciones con cobre, plomo y cinc

    Directory of Open Access Journals (Sweden)

    Alfonso Clavijo Díaz

    2010-09-01

    Full Text Available Se desarrolla un modelo químico-matemático con fundamento en los equilibrios ácido-base y asistido por un computador personal, para el análisis de iones metálicos aislados o en mezclas. Se elaboran curvas de titulación teóricas teniendo en cuenta el quelón, el pH, las especies formadoras de complejos (auxiliares y enmascarantes y el uso de un indicador metalocrómico. Como resultado de lo anterior, se desarrolla un método de análisis volumétrico (quelatometría para la determinación cuantitativa de los iones cobre, plomo y cinc en aleaciones.

  14. Niveles de plomo en la población de alto riesgo y su entorno en San Ignacio, Fresnillo, Zacatecas, México Lead levels in high-risk populations and the surrounding environment in San Ignacio, Fresnillo, Zacatecas, México

    OpenAIRE

    Eduardo Manzanares-Acuña; Héctor René Vega-Carrillo; Miguel Ángel Salas-Luévano; Víctor Martín Hernández-Dávila; Consuelo Letechipía-de León; Rómulo Bañuelos-Valenzuela

    2006-01-01

    OBJETIVO: Determinar la concentración de plomo en la sangre de niños y mujeres, en periodo de lactancia o embarazadas, de la comunidad de San Ignacio, Fresnillo, en Zacatecas, así como en matrices de suelo, plantas, ceniza y barro vidriado, para determinar la exposición que genera una empresa recicladora de metales. MATERIAL Y MÉTODOS: El estudio se realizó de diciembre de 2004 al mes de abril de 2005. El Pb en sangre se midió por voltamperometría de redisolución anódica, mientras que se util...

  15. Prácticas y Cambios Contables en la Minería del Plomo de la Carolina (Jaén): Estudio de la Empresa Minera el Guindo en los Años Finales del S. XIX y Primer Cuarto del S. XX

    OpenAIRE

    José M.ª Carlos Álvarez López; Luis Garrido González; Juan Luis Lillo Criado

    2006-01-01

    Hemos investigado sobre los libros contables de la sociedad minera El Guindo (sucursal de la Carolina), situada en el sur de España y dedicada a la extracción de plomo, con el fin de examinar sus prácticas contables y los avances producidos en ellas. Destacamos, como cambios esenciales, en el primer periodo analizado (1899-1925), el paso del criterio de caja al criterio de devengo en los libros principales y, fundamentalmente, la introducción de un criterio de valoración para minerales basado...

  16. Análisis de Cadmio y Plomo en aguas superficiales por potenciometría de Stripping

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    Juan Miguel Arias

    2010-12-01

    Full Text Available Se realizó la implementación y validación de una metodología analítica para determinar la presencia de cadmio y plomo en aguas supjerficiales como herramienta para la descripción del estado actual y el control cualitativo y cuantitativo de las descargas de estos metales peligrosos en los cuerpos de agua.

  17. Morphological and Chemical Relationships in Nanotubes Formed by Anodizing of Ti6al4v Alloy

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    Kaczmarek- Pawelska A.

    2014-12-01

    Full Text Available The electrochemical formation of oxide nanotubes on the Ti6Al4V alloy has been so far difficult due to easy dissolution of vanadium reach β-phase of the two phase material. Due to the topographical heterogeneity of the anodic layer in nano and microscale at anodizing of the Ti6Al4V alloy we focused to establish the relationships between nanotube diameters on both phases of the alloy and fluorides concentration in electrolyte. We studied the effect of fluoride concentration (0.5-0.7 wt.% in 99% ethylene glycol on morphological parameters of nanotube layer on the Ti6Al4V alloy anodized at 20V for 20 min. Nanotubes with diameter ~40-50 nm ±5nm on the entire Ti6Al4V alloy surface in electrolyte containing 0.6% wt. NH4F were obtained. Microscale roughness studies revealed that nanotubular layer on α-phase is thicker than on β-phase. The annealing of nanotube layers at 600°C for 2h in air, nitrogen and argon, typically performed to improve their electrical properties, influenced chemical composition and morphology of nanotubes on the Ti6Al4V alloy. The vanadium oxides (VO2, V2O3, V2O5 were present in surface nanotube layer covering both phases of the alloy and the shape of nanotubes was preserved after annealing in nitrogen.

  18. Evaluación de plomo en el ambiente ocupacional de una industria de baterías

    Directory of Open Access Journals (Sweden)

    Lina V. Hernández

    2011-03-01

    Full Text Available Se realizó un estudio de evaluación de riesgo ocupacional por la presencia de plomo en el aire, en una mediana industria de reciclaje y fabricación de baterías eléctricas ubicada en Bogotá, Colombia. Se tomaron muestras de aire en la zona de respiración de las personas, mediante bombas de muestreo personal con filtros de acetato de celulosa para captación de partículas, y se aplicó la metodología de muestreo parcial con muestras consecutivas. El contenido de plomo fue determinado por absorción atómica con llama. Se encontraron concentraciones de plomo en el aire entre no detectable y 6,23 mg Pb/m3 de aire. Los resultados indican que se supera el valor límite umbral (TLV de 0,04 mg Pb/m3 de aire, corregido para la jornada laboral de 48 horas, en actividades de fundición, formación de placas, empaste y oficios varios. La evaluación de riesgo ocupacional confirma el riesgo en todos los puestos de trabajo y en las actividades señaladas durante la mayoría de los muestreos realizados.

  19. Validación de la metodología para la determinación cuantitativa de plomo en tintes cosméticos disponibles en el mercado nacional por espectroscopia de absorción atómica con llama

    Directory of Open Access Journals (Sweden)

    Paulina Silva Trejos

    2008-04-01

    Full Text Available Se validó la metodología analítica para determinar cuantitativamente plomo en tintes cosméticos disponibles en el mercado nacional, por el método de espectroscopia de absorción atómica con llama. Las muestras se digirieron por digestión húmeda con HNO3 al 65 % m/men horno de microondas; el porcentaje de recuperación para la digestión de muestras de 0,25 g y 0,45 g en 5,00 mL fue de 100,5±0,5. El ámbito de linealidad óptimo fue del límite de detección a 5,0 mg/L con un coeficiente de correlación de 0,9998.Los límites de detección y los límites de cuantificación determinados gráficamente por el método de corredor de errores para regresión lineal fueron de 0,12 ±0,02 mg/L y 0,21±0,02 mg/L, respectivamente. Se evaluó la precisión determinando la repetitividad como desviación estándar de 5 réplicas de un tinte positivo para plomo, de acuerdo con la definición de la ISO,2√2*σ, y se obtuvo un valor de 2,3. La veracidad se determinó por medio de los porcentajes de recuperación evaluados, agregando alícuotas de patrones de plomo a muestras de tinte y comparándolo con muestras de igual masa a las que no se les realizó adición. Las muestras de tintes se obtuvieron en puestos de venta, tales como farmacias, suplidoras de belleza,supermercados, centros de ventas de productos naturales y el mercado central de San José. De los tintes analizados, de marca Youthair, de fabricación norteamericana, Doni, Mont D’Or, Matador y Siempre Joven, producidos localmente, contienen acetato de plomo como ingrediente activo

  20. Pb-Al relationships in waterfowl feces discriminate between sources of Pb exposure

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Haro, M. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 13071 Ciudad Real (Spain); Department of Wetland Ecology, Estacion Biologica de Donana - CSIC, Americo Vespucio, 41092 Sevilla (Spain); Taggart, M.A. [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 13071 Ciudad Real (Spain); Mateo, R., E-mail: rafael.mateo@uclm.e [Instituto de Investigacion en Recursos Cinegeticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 13071 Ciudad Real (Spain)

    2010-07-15

    Hunted mallards (n = 56) were collected in the Ebro Delta (Spain) in 2007-08 to evaluate the use of feces as a non-invasive monitoring method to study lead shot ingestion. The prevalence of Pb shot ingestion in these birds was 28.6%, and similar to that reported before a ban on Pb shot use in 2003. Lead concentrations in terminal intestinal contents were higher in mallards with Pb shot in their gizzard. Feces Pb concentrations >34 {mu}g/g d.w were indicative of Pb shot ingestion, and background Pb levels were <12.5 {mu}g/g d.w. To discriminate between birds ingesting soil Pb, and those ingesting Pb shot, we correlated Al and Pb levels and showed that mallards with ingested Pb shot in the gizzard stood out as outliers within the regression. Feces Pb-Al relationships can be used as a simple non-invasive tool in monitoring programs regarding Pb shot ingestion in birds. - By analysing Pb-Al levels in feces, a simple non-invasive method can help determine sources of Pb exposure in waterfowl.

  1. Pb-Al relationships in waterfowl feces discriminate between sources of Pb exposure

    International Nuclear Information System (INIS)

    Hunted mallards (n = 56) were collected in the Ebro Delta (Spain) in 2007-08 to evaluate the use of feces as a non-invasive monitoring method to study lead shot ingestion. The prevalence of Pb shot ingestion in these birds was 28.6%, and similar to that reported before a ban on Pb shot use in 2003. Lead concentrations in terminal intestinal contents were higher in mallards with Pb shot in their gizzard. Feces Pb concentrations >34 μg/g d.w were indicative of Pb shot ingestion, and background Pb levels were <12.5 μg/g d.w. To discriminate between birds ingesting soil Pb, and those ingesting Pb shot, we correlated Al and Pb levels and showed that mallards with ingested Pb shot in the gizzard stood out as outliers within the regression. Feces Pb-Al relationships can be used as a simple non-invasive tool in monitoring programs regarding Pb shot ingestion in birds. - By analysing Pb-Al levels in feces, a simple non-invasive method can help determine sources of Pb exposure in waterfowl.

  2. Vermeer: Los colores tóxicos del plomo y del mercurio

    Directory of Open Access Journals (Sweden)

    T Camacho

    2011-01-01

    Full Text Available ¿Qué sucede con Vermeer?, se preguntan los historiadores y amantes del arte. El enigmático pintor permaneció en la oscuridad después de su muerte hasta el siglo XIX, en donde capturaría la imaginación y el gusto estético de los tiempos modernos. Aunque han llegado a nosotros sólo treinta y seis de sus obras, su originalidad y refinamiento le colocan entre los más grandes artistas holandeses del siglo XVII. La vida de Vermeer sólo puede recompuesta a través de actas notariales y su dramático final es conocido por boca de su viuda. Nosotros pretendemos aportar un nuevo punto de vista de las razones de su muerte a causa de una intoxicación por plomo y mercurio, y las repercusiones que esta causa tuvo en su pintura.

  3. Intoxicación por plomo y otros problemas de salud en niños de poblaciones aledañas a relaves mineros

    OpenAIRE

    Jonh Astete; Walter Cáceres; María del Carmen Gastañaga; Martha Lucero; Iselle Sabastizagal; Tania Oblitas; Jessie Pari; Félix Rodríguez

    2009-01-01

    Objetivos. Determinar los niveles de plomo y otros problemas de salud en menores de 10 años residentes en las comunidades de Quiulacocha y Champamarca, Pasco. Materiales y métodos. Estudio transversal realizado en septiembre de 2005. Se incluyó a todos los niños de ambas comunidades altoandinas aledañas a relaves mineros. Se realizó medición de los niveles de plomo y hemoglobina en sangre así como la evaluación antropométrica y del desarrollo psicomotor. Resultados. La prevalencia de intoxica...

  4. Contenidos de Cadmio, Cobre, Zinc y Plomo en órganos de Rhizophora mangle de la Ciénaga Grande de Santa Marta, Caribe colombiano.

    OpenAIRE

    Naranjo-Sánchez, Y.A.; Troncoso-Olivo, W.

    2008-01-01

    Para determinar los contenidos de cadmio, cobre, zinc y plomo en hojas, tallos y raíces de Rhizophora mangle se tomaron muestras en tres parcelas ubicadas en la desembocadura del río Sevilla-Ciénaga Grande de Santa Marta, en octubre de 2003. Las mediciones de las concentraciones de metales, se hicieron mediante la técnica de espectrometría de emisión atómica de plasma inductivamente acoplado (ICP-AES). Los resultados indicaron que la concentración de plomo en órganos de R. mangle estuvo bajo ...

  5. Niveles de plomo y cadmio en agua marina y lapas (Patella vulgata L.) de la Ría de Vigo

    OpenAIRE

    Pérez López, M.; M.C Nóvoa; J. Alonso; M. A. García Fernández; M.J. Melgar

    2003-01-01

    El empleo de seres vivos para monitorizar la contaminación por metales pesados en los ecosistemas acuáticos es de extremo interés en el campo de la ecotoxicología. En el presente estudio se han recogido muestras de agua marina y de lapas (Patella vulgata L.) de distintos puntos de la Ría de Vigo, con la intención de determinar en ellos los niveles de plomo y cadmio, por medio de una técnica de voltamperometría. Los resultados obtenidos mostraron una relación estrecha entr...

  6. Estudio de los niveles de plomo, cadmio, zinc y arsénico, en aguas de la provincia de Salamanca

    Directory of Open Access Journals (Sweden)

    Blanco Hernández Angel Luis

    1998-01-01

    Full Text Available FUNDAMENTOS: Conocer el grado de contaminación por plomo, cadmio, cinc y arsénico de las aguas de la provincia de Salamanca y su relación con la zona de procedencia de las muestras y el punto de recogida de las mismas. MÉTODO: Estudio epidemiológico transversal, observacional y descriptivo. Se han estudiado aguas procedentes de redes de abastecimiento, fuentes, manantiales, pozos, ríos, riveras y lagunas de la provincia de Salamanca, analizándose los contenidos de plomo, cadmio, zinc y arsénico de 180 muestras, mediante espectroscopía de absorción atómica. Se han comparado los niveles de contaminación por los cuatro elementos de las muestras de agua entre las cuatro unidades comarcales de la provincia. Se han comparado los niveles de contaminación por los cuatro elementos entre las aguas procedentes de redes de abastecimiento y aquellas muestras de pozos, fuentes, manantiales y aguas de superficie. RESULTADOS: Los resultados indican que un 56% de las muestras analizadas superan las concentraciones máximas admisibles de cadmio, y un 28% del total de muestras analizadas supera las concentraciones máximas admisibles de plomo, según la legislación vigente presentando niveles tolerables de zinc y arsénico. No se han observado diferencias importantes en el grado de contaminación de las aguas por los elementos estudiados entre las cuatro unidades comarcales de la provincia. No se han observado diferencias en los niveles de contaminación por los cuatro elementos entre las aguas procedentes de redes de abastecimientos y aquellas muestras de pozos, fuentes, manantiales y aguas de superficie. CONCLUSIONES: Los resultados sugieren que las aguas de la provincia de Salamanca presentan de forma "natural" altos contenidos de cadmio y plomo, probablemente debido a las características geológicas del terreno.

  7. The Microstructure-Processing-Property Relationships in an Al Matrix Composite System Reinforced by Al-Cu-Fe Alloy Particles

    Energy Technology Data Exchange (ETDEWEB)

    Fei Tang

    2004-12-19

    Metal matrix composites (MMC), especially Al matrix composites, received a lot of attention during many years of research because of their promise for the development of automotive and aerospace materials with improved properties and performance, such as lighter weight and better structural properties, improved thermal conductivity and wear resistance. In order to make the MMC materials more viable in various applications, current research efforts on the MMCs should continue to focus on two important aspects, including improving the properties of MMCs and finding more economical techniques to produce MMCs. Solid state vacuum sintering was studied in tap densified Al powder and in hot quasi-isostatically forged samples composed of commercial inert gas atomized or high purity Al powder, generated by a gas atomization reaction synthesis (GARS) technique. The GARS process results in spherical Al powder with a far thinner surface oxide. The overall results indicated the enhanced ability of GARS-processed Al and Al alloy powders for solid state sintering, which may lead to simplification of current Al powder consolidation processing methods. Elemental Al-based composites reinforced with spherical Al-Cu-Fe alloy powders were produced by quasi-isostatic forging and vacuum hot pressing (VHP) consolidation methods. Microstructures and tensile properties of AYAl-Cu-Fe composites were characterized. It was proved that spherical Al-Cu-Fe alloy powders can serve as an effective reinforcement particulate for elemental Al-based composites, because of their high hardness and a preferred type of matrix/reinforcement interfacial bonding, with reduced strain concentration around the particles. Ultimate tensile strength and yield strength of the composites were increased over the corresponding Al matrix values, far beyond typical observations. This remarkable strengthening was achieved without precipitation hardening and without severe strain hardening during consolidation because of

  8. Determinants of blood-lead levels in children in Callao and Lima metropolitan area Determinación de los niveles de plomo en sangre de niños de El Callao y del área metropolitana de Lima

    Directory of Open Access Journals (Sweden)

    Rocío Espinoza

    2003-01-01

    . En esta zona se detectó un área de almacenamiento de minerales como una fuente importante de exposición. Los niños que viven cerca de esta área tenían en promedio un exceso de 13 µg/dl en sangre. Para los participantes de la zona de Lima el riesgo de presentar niveles por encima de 10 µg/dl se asoció con la exposición a tráfico vehicular. CONCLUSIONES: Para Lima Metropolitana se puede concluir que los niveles de plomo en sangre no representan un problema urgente, sin embargo, el reducir el plomo de la gasolina se acompaña de un beneficio importante. En contraste, para el área cercana al puerto de El Callao, nuestro estudio demuestra la presencia de sitios de almacenamiento de minerales que representan un riesgo importante para la salud de los niños que viven en esta zona.

  9. Influencia de las propiedades edáficas en la electromovilidad del plomo y cinc en el suelo de Ciudad Real

    OpenAIRE

    Ruiz López, Carmen

    2014-01-01

    En el presente trabajo de investigación se ha llevado a cabo el estudio de las propiedades de distintos tipos de suelos de Ciudad Real y se ha visto cómo influían esas propiedades en la electromovilidad del plomo y cinc.

  10. The crystallography of continuous precipitates with a newly observed orientation relationship in an Mg-Al-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, O.; Zhou, J.P. [Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China); Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China); Zhao, D.S. [Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China); Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China)], E-mail: dszhao@whu.edu.cn; Wang, J.B.; Wang, R.H.; Gui, J.N.; Xiong, D.X. [Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072 (China); Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China); Sun, Z.F. [College of Material Science and Engineering, Chongqing Institute of Technology, Chongqing 400050 (China)

    2009-05-15

    A new orientation relationship (OR) between {gamma}-Mg{sub 17}Al{sub 12} precipitate and magnesium matrix is identified by the selected-area electron diffraction technique, together with the convergent beam electron diffraction method. The stereogram for the new orientation relationship has been calculated and discussed along with the stereograms for the Pitsch-Schrader OR, the Burgers OR, the Potter OR, the Crawley OR, the Porter OR and the Gjoennes-Ostmoe OR in the Mg-Al-based system.

  11. Methodological issues related to studies of lead mobilization during menopause Consideraciones metodológicas relacionadas con estudios sobre movilización de plomo durante la menopausia

    Directory of Open Access Journals (Sweden)

    Gertrud S. Berkowitz

    1999-11-01

    Full Text Available While there has been a substantial decline in lead exposure in the United States during the past two decades, mobilization of existing lead stored in bone potentially represents an important endogenous source of exposure for menopausal women. It has been hypothesized that lead may be mobilized from skeletal stores during conditions of high bone turnover, such as during menopause. However, such mobilization has not been documented in prospective studies. This discussion is focussed on some of the methodological difficulties to be anticipated in longitudinal studies of lead mobilization specific to menopause and the issues that need to be taken into account when evaluating the results of such studies. To evaluate whether lead mobilization occurs during menopause, a prospective repeated measures design is needed using X-ray fluorescence analysis of lead in bone and serial measurements of blood lead. Potential confounders and effect modifiers also need to be taken into account in the statistical analysis.Mientras que la exposición a plomo ha declinado sustancialmente en Estados Unidos durante las dos décadas pasadas, la mobilización del plomo almacenado en los huesos representa potencialmente una importante fuente de exposición endógena en mujeres menopáusicas. No obstante, tal movilización no ha sido documentada por estudios prospectivos. La presente discusión se enfoca en algunas de las dificultades metodológicas a se anticipadas en estudios longitudinales de mobilización de plomo específicamente en la menopausia, y los aspectos que necesitan ser considerados cuando se evalúan los resultados de tales estudios. Para evaluar si durante la menopausia el plomo es mobilizado, se requiere de un diseño prospectivo con mediciones repetidas utilizando análisis de fluorescencia de rayos-X para determinar el plomo en hueso y una serie de mediciones de plomo en sangre. Los potenciales confusores y modificadores del efecto también deben tomarse

  12. The relationship between viscosity and glass forming ability of Al-(Ni)-Yb alloy systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The dynamic viscosity of Al-Yb and Al-Ni-Yb superheated melts was measured using a torsional oscillation viscometer. The results show that the temperature dependence of viscosity fits the Arrhenius law well and the fitting factors are calculated. The amorphous ribbons of these alloys were produced by the melt spinning technique and the thermal properties were characterized by using a differential scanning calorimetry (DSC). E (the activation energy for viscous flow), which reflects the change rate of viscosity, has a good negative relation with the GFA in both Al-Yb and Al-Ni-Yb systems. However, there is no direct relation between liquidus viscosity (ηL) and GFA. The superheated fragility M can predict GFA in Al-Yb or Al-Ni-Yb alloy system.

  13. Las Metalotioneínas de mamífero como agentes detoxificadores de plomo(II)

    OpenAIRE

    Pérez Zúñiga, Catalina Trinidad

    2013-01-01

    El plomo es uno de los metales más nocivos para la salud humana y su incidencia en la misma deber ser tenida en cuenta debido a su amplia distribución en el medio ambiente. El catión Pb(II) interactúa preferentemente con proteínas que contienen Zn(II) (ALAD, CadC, GATA, dedos de Zn) y Ca(II) (CaM, PKC, syt) causando no sólo interferencias en algunos procesos metabólicos (principalmente la biosíntesis de hemoglobina), sino que también inhibe varias enzimas, provocando daños en el sistema nervi...

  14. Método práctico para determinar protoporfirina libre eritrocitaria como marcador biológico ante la exposición a plomo inorgánico

    Directory of Open Access Journals (Sweden)

    Gloria Marilé Ávalos Ávalos

    2014-10-01

    Full Text Available Introducción: para la evaluación de la exposición ocupacional a plomo inorgánico se utilizan diversos biomarcadores de exposición, entre ellos la determinación de plomo en sangre y la de protoporfirina libre eritrocitaria. Objetivo: determinar la fiabilidad práctica y comparativa de un método espectrofotométrico sencillo para determinar protoporfirina libre en eritrocitos como marcador biológico de la exposición a plomo inorgánico. Métodos: se estudiaron a 40 trabajadores expuestos a plomo con diferentes niveles, a cada uno de ellos se les tomó una muestra de sangre para determinar protoporfirina libre eritrocitaria y plomo, y una muestra de orina para determinar ácido aminolevulínico. Se seleccionó un grupo control de 20 trabajadores no expuestos, donde se correlacionaron las concentraciones halladas de protoporfirina libre eritrocitaria y de ácido aminolevulínico con las de plomo en sangre. Resultados: la correlación entre las concentraciones de protoporfirina libre eritrocitaria y las de plomo en sangre fue mayor y más significativa estadísticamente en los trabajadores expuestos, que la encontrada entre el ácido aminolevulínico y el plomo en sangre de los no expuestos. La técnica propuesta de determinación de protoporfirina libre eritrocitaria, además de resultar exacta, precisa y sensible, es sencilla de realizar en, prácticamente cualquier laboratorio químico con un mínimo de recursos. Conclusiones: la técnica propuesta es confiable y puede ser utilizada en una primera opción en el control higiénico-sanitario de la exposición ocupacional a plomo inorgánico, acudiéndose solamente, de ser imprescindible, a la determinación de plomo en sangre cuando las concentraciones de protoporfirina libre eritrocitaria resulten significativamente altas.

  15. Intervención ambiental en sitios contaminados por plomo: la experiencia en los Estados Unidos de América Environmental intervention in sites contaminated by lead: the United States of America experience

    Directory of Open Access Journals (Sweden)

    Nicholas Ceto

    2003-01-01

    Full Text Available Durante una década, los organismos estatales y federales han trabajado de manera conjunta con las comunidades a lo largo del territorio estadounidense, con el objeto de valorar el riesgo a la salud que implica la contaminación por plomo en las zonas residenciales. A menudo dichas comunidades han estado vinculadas con instalaciones destinadas anteriormente a actividades como la minería y la metalurgia; sin embargo, existen otras industrias como por ejemplo la fabricación de pinturas y el reciclaje de baterías, también identificadas como fuentes de contaminación por este metal. La vasta experiencia en las tareas de limpieza de los sitios contaminados ha puesto de manifiesto que los amplios programas destinados a identificar y manejar las vías de exposición pueden ayudar, de manera efectiva, a disminuir los niveles de plomo en sangre de las poblaciones más suceptibles, como la de los de niños en edades tempranas. Los programas de intervención ambiental son más efectivos cuando en las localidades afectadas se ejecutan programas de educación/intervención en salud, orientados al desarrollo de estrategias individualizadas para manejar el riesgo que implica la presencia de dicho metal en el ambiente.For a decade, state and federal agencies have worked jointly with communities throughout the USA, with the objective of measuring the health-risk from lead pollution in residential zones. Often these communities have been linked with facilities previously associated with activities like mining and metallurgy; nevertheless, there are other industries like paint manufacturing and battery recycling, that have also been identified as lead pollution sources. The vast experience in cleaning up the contaminated sites has shown that ample programs designed to identify and handle the exposure routes can help, in an effective manner, to diminish blood lead levels (BLL in susceptible populations, such as in young children. Environmental intervention

  16. Intoxicación por plomo y otros problemas de salud en niños de poblaciones aledañas a relaves mineros

    Directory of Open Access Journals (Sweden)

    Jonh Astete

    2009-01-01

    Full Text Available Objetivos. Determinar los niveles de plomo y otros problemas de salud en menores de 10 años residentes en las comunidades de Quiulacocha y Champamarca, Pasco. Materiales y métodos. Estudio transversal realizado en septiembre de 2005. Se incluyó a todos los niños de ambas comunidades altoandinas aledañas a relaves mineros. Se realizó medición de los niveles de plomo y hemoglobina en sangre así como la evaluación antropométrica y del desarrollo psicomotor. Resultados. La prevalencia de intoxicación por plomo (Pb>10 µg/dL fue de 84,7%, la media de plumbemia fue 15,79 ± 4,85 µg/dL (rango: 6,17-34,53 µg/dL. La mayoría (55,8% de los niños de ambas comunidades estaban con desnutrición crónica, 23,0% tenían anemia, y 5,9% tenían retardo mental. Los niños de Quiulacocha tenían un desarrollo psicomotor normal en 79,2% de los casos y en Champamarca 85,4%. Conclusiones. Cuatro de cada cinco niños de estas comunidades tiene intoxicación plúmbica. Los relaves mineros son una fuente de contaminación por plomo para los niños que viven en zonas aledañas, se deben realizar intervenciones en estas comunidades.

  17. Niveles de plomo en los individuos de la necrópolis tardorromana de la c/ Virgen de la Misericordia (Valencia)

    OpenAIRE

    Gallello, Gianni; Larini, Alessia; Bartoli, Fulvio; Mallegni, Francesco; Díaz Pastor, Agustín; Díez Castillo, Agustín

    2014-01-01

    El objetivo general de este estudio ha sido determinar los contenidos de plomo (Pb) en restos de huesos y suelos de la necrópolis de la c/ Virgen de la Misericordia (Valencia) para reconstruir el proceso de transición del elemento (desde el sedimento hacia los huesos y viceversa) debido a la acción de los procesos diagenéticos.

  18. Correlación de protoporfirina zinc y plomo en sangre en trabajadores de fábricas de baterías, de Bogotá, Colombia

    Directory of Open Access Journals (Sweden)

    Cárdenas-Bustamante Omayda

    2001-01-01

    Full Text Available Objetivo. Determinar la utilidad de la protoporfirina zinc en sangre (PPz como indicador de exposición a plomo en trabajadores de fábricas de baterías. Material y métodos. Se hizo un estudio transversal en 116 trabajadores de fábricas de baterías del sector informal en Bogotá, Colombia. La información sobre variables generales, ocupacionales y de salud fue obtenida por medio de una entrevista con los trabajadores. Se establecieron dos categorías para los valores de PPz: aquellos por debajo del valor límite de (70 µg/dl, y aquellos por arriba de este valor. Se empleó análisis de regresión lineal para medir la correlación entre los valores logarítmicos de PPz (>70 µg/dl y plomo en sangre (PbS (>38 µg/dl. Resultados. Se encontró un coeficiente de correlación semilogarítmica r=0.54, además de posibles asociaciones estadísticamente significativas entre los niveles elevados de PPz y el oficio actual de exposición directa (RM:3.35, IC 95% 1.02-11.91; p:0.02, emplear plomo como materia prima (RM:7.80, IC 95% 2.96-21.03; phttp://www.insp.mx/salud/index.html

  19. Acumulación de plomo en hueso y sus efectos en la salud Lead storage in bone and its effects on health

    Directory of Open Access Journals (Sweden)

    Luz Helena Sanín

    1998-07-01

    Full Text Available Los efectos nocivos del plomo han sido conocidos desde tiempos antiguos por su amplia gama; este metal afecta prácticamente todos los órganos y sistemas del cuerpo humano. Recientemente se han documentado efectos tóxicos crónicos en los sistemas cardiovascular y nervioso, con niveles que antes se consideraban seguros. El sitio primario de almacenamiento de plomo en el organismo es el hueso, pero sólo hasta fechas recientes se ha clarificado la significancia toxicológica de este hecho. En este artículo se analiza el papel del plomo en hueso como fuente de exposición endógena, como biomarcador de exposición crónica y como tejido blanco. Se presentan además los avances recientes para la medición de plomo en hueso mediante los rayos X-fluorescentes (XRF. Finalmente se revisa la importancia, para la salud pública, de estudiar y medir el plomo en hueso en lugares con una historia de exposición crónica como la Ciudad de México y en los ambientes ocupacionales, especialmente como fuente remanente de exposición. Se analiza especialmente el caso de mujeres en edad reproductiva, quienes pueden convertirse en fuentes de exposición para el feto y para el niño amamantado.The adverse effects of lead have been known for long since the metal affects practically all organs and systems of the human body. Recently, toxic effects have been reported in the cardiovascular and nervous systems at lead levels previously considered to be secure. The main lead storage site in the body is bone. The toxicologic significance of this fact has been clarified only recently. The present study analyzes the role of lead as an endogenous source of exposure, as a chronic exposure biomarker and as a target organ. Recent advances to measure bone lead through fluorescent X-Rays are discussed. Additionally, the importance of bone lead from a public health perspective in places with a chronic history of exposure such as Mexico City, and in some occupational

  20. Relationships among the Microstructure, Mechanical Properties, and Fatigue Behavior in Thin Ti6Al4V

    Directory of Open Access Journals (Sweden)

    Y. Fan

    2016-01-01

    Full Text Available The microstructures of Ti6Al4V are complex and strongly affect its mechanical properties and fatigue behavior. This paper investigates the role of microstructure on mechanical and fatigue properties of thin-section Ti6Al4V sheets, with the aim of reviewing the effects of microstructure on fatigue properties where suboptimal microstructures might result following heat treatment of assemblies that may not be suited to further annealing, for example, following laser welding. Samples of Ti6Al4V sheet were subjected to a range of heat treatments, including annealing and water quenching from temperatures ranging from 650°C to 1050°C. Micrographs of these samples were inspected for microstructure, and hardness, 0.2% proof stress, elongation, and fracture strength were measured and attributed back to microstructure. Fractography was used to support the findings from microstructure and mechanical analyses. The strength ranking from high to low for the microstructures of thin Ti6Al4V sheets observed in this study is as follows: acicular α′ martensite, Widmanstätten, bimodal, and equiaxed microstructure. The fatigue strength ranking from high to low is as follows: equiaxed, bimodal, Widmanstätten, and acicular α′ martensite microstructure.

  1. Origin of the modified orientation relationship for S(S'')-phase in Al-Mg-Cu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kovarik, L. [Department of Materials Science and Engineering, Ohio State University, 2041 College Road, Watts Hall 477, Columbus, OH 43201 (United States)]. E-mail: kovarik.8@osu.edu; Miller, M.K. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6136 (United States); Court, S.A. [Novelis Technology AG, CH-8212 Neuhausen (Switzerland); Mills, M.J. [Department of Materials Science and Engineering, Ohio State University, 2041 College Road, Watts Hall 477, Columbus, OH 43201 (United States)

    2006-04-15

    The formation of S-phase with a modified orientation relationship (OR) has been previously observed in several Al-Cu-Mg alloys. In this paper, high-resolution transmission electron microscopy and Z-contrast imaging have been used to study the origin of the modified OR in an alloy with low Cu/Mg ratio and small Si addition. Based on the observations, and supported by ab initio simulations, the formation is governed by coherency at the (0 2 1){sub S}//(0 1 4){sub Al} S-phase/matrix interface, which is shown to coexist with the more commonly reported (0 0 1){sub S}//(0 2 1){sub Al} interface. This new (0 2 1){sub S}//(0 1 4){sub Al} S-phase/matrix interface explanation is compared with previously published explanations based on the invariant line concept and establishment of a different S-phase/matrix interface. Energy dispersive X-ray spectroscopy and atom probe tomography indicate that the S-phase is slightly enriched in Si. The role of Si as well as the overall alloy composition is discussed. Because of the similarities between our results and the early work of Bagaryatsky, the S''-phase notation is adopted for this early-forming, strained version of the S-phase.

  2. Processing-microstructure-property relationships for cold spray powder deposition of Al-Cu alloys

    OpenAIRE

    Leazer, Jeremy D.

    2015-01-01

    Approved for public release; distribution is unlimited This thesis presents research on the cold gas-dynamic spray process applied to the deposition of aluminum-copper alloy coatings. Cold spray deposition is a process utilized to create corrosion protection coatings and to perform additive repair for aluminum structures. This thesis utilized a series of Al-Cu binary alloy powders, from 2–5 weight percent copper and characterized their chemistry and microstructure. The powders were deposit...

  3. Relationship between bias voltage and microstructure as well as properties of CrAlYN films

    Institute of Scientific and Technical Information of China (English)

    付英英; 李红轩; 吉利; 刘晓红; 刘流; 周惠娣; 陈建敏

    2015-01-01

    In this work, a series of CrAlYN films doped with 1 at.%yttrium were deposited by unbalanced reactive magnetron sputtering under different bias voltages. The effects of bias voltage on microstructure and properties of the CrAlYN films were subsequently investigated. It is found that all the as-deposited films have similar chemical composition and crystalline structure. However, the bias voltage has significant impact on the mechanical properties and oxidation resistance of the resulting films. Namely, the film deposited at 100 V has the highest hardness and best oxidation resistance, which are mainly attributed to its denser structure and higher Al content than others. In addition, the film obtained at 100 V exhibits superior oxidation resistance even at 1000 ◦C, and good friction and wear properties at 600 and 800 ◦C, and the latter two are mainly ascribed to the formation of compact transfer layer on the worn surfaces. However, this film experienced obvious wear loss at low testing temperatures (i.e., 200 and 400◦C) due to the serious abrasive wear.

  4. Relationship between Matern al Nutritional Status and Infant Birth Weight of Vegetarians in DKI Jakarta

    Directory of Open Access Journals (Sweden)

    Sandra Fikawati

    2012-06-01

    Full Text Available Infant’s birth weight, especially low birth weight (LBW, areintergenerational issues that will affect the cycle of life.Vegetarian diets are at risk because limited food consumption could cause nutrient deficiencies. This retrospective studyaims to determine the relationship between maternal nutritional status (pre-pregnancy body mass index (BMI and weight gain during pregnancy and infant’s birth weight among vegetarians in Jakarta. The total sample of 85 children aged 1 month to 5 years was selected purposively. Results showed that the mean of pre-pregnancy BMI of vegetarian mothers is 20.2 kg/m2 (±2.2 kg/m2, pregnancy weight gain is 15.5 kg (±6.4 kg and infant’s birth weight is 3212 gs (±417.7 gs. Pre-pregnancy BMI and pregnancy weight gain were significantly associated with infant’s birth weight of vegetarians. There is no relationship between pre-pregnancy BMI and pregnancy weight gain. Multivariate analysis found that pre-pregnancy BMI, protein, vitamin B12, iron, and Zn intakes and sex has relationship with infant’s birthweight. It is recommended that vegetarian mothers should get information about the importance of pre-pregnancy nutrition, optimal pregnancy weight gain, and maintaining adequate intake of protein, vitamin B12, iron, and Zn during pregnancy

  5. Relationship between Atmospheric Dew Point and Sinterability of Al-Si Based Alloy

    Institute of Scientific and Technical Information of China (English)

    A. Manonukul; A. Salee

    2013-01-01

    Al-Si based alloys are interestingly used to produce automotive components.Fabrication of such components by powder metallurgy (PM) has been developed continuously.During PM,several parameters affect the sinterability of the aluminium powder,including atmospheric dew point which is regarded as one of the crucial parameters.The objective of this work was to investigate the effect of the atmospheric dew point on the sinterability of Al-14.9Si-2.4Cu-0.55Mg by studying the sintering characters obtained under various atmospheric dew points.The aluminium alloy powder was pressed into tensile specimens and subsequently sintered in a nitrogen atmosphere at 560 ℃ for 60 min with varied atmospheric dew points.The results show that as the dew point decreased,the sintered properties were improved.The atmospheric dew point of-38.4 ℃ is sufficient to obtain good sintering characters and it is achievable in a commercial furnace.

  6. Modeling the Constitutive Relationship of Powder Metallurgy Ti-47Al-2Nb-2Cr Alloy During Hot Deformation

    Science.gov (United States)

    Sun, Yu; Hu, Lianxi; Ren, Junshuai

    2015-03-01

    In the present work, the isothermal compression tests of PM alloy Ti-47Al-2Nb-2Cr were carried out in the temperature range of 950-1200 °C. A Gleeble 1500D thermosimulation machine was used, and samples were tested at strain rates ranging from 10-3 to 10-1 s-1. Based on the obtained flow stress curves, the hot deformation behavior was presented. The constitutive relationship of powder metallurgy (PM) Ti-47Al-2Nb-2Cr alloy was developed using an Arrhenius-type constitutive model that involves strain compensation in addition to an artificial neural network model. The accuracy and reliability of the developed models were quantified in terms of statistical parameters such as correlation coefficient and absolute value of relative error. It was found that deformation temperature and strain rate have obvious effects on the flow characteristics, and the flow stress increases with the increasing strain rate and the decreasing temperature. Moreover, the proposed models possess excellent prediction capability of flow stresses for the present alloy during hot deformation. Compared with the traditional Arrhenius-type model, the backpropagation neural network model is more accurate when presenting the isothermal compressing deformation behavior at elevated temperatures for PM Ti-47Al-2Nb-2Cr alloy.

  7. Contaminación por perdigones de plomo en humedales y evaluación de los aportes de grit como medida para reducir el plumbismo en aves acuáticas.

    OpenAIRE

    Martínez Haro, Mónica

    2010-01-01

    Con esta Tesis Doctoral se ha estudiado la problemática de la intoxicación por plomo en aves acuáticas en lagunas gaditanas con elevadas densidades de perdigones de plomo en sedimento, y se ha profundizado en el conocimiento de la selección de grit por aves acuáticas, con el fin de conocer diversos aspectos que pueden ser importantes de cara a poner en práctica el aporte de grit como medida paliativa del plumbismo. Los resultados obtenidos indican que las aves acuáticas, y en especial las aná...

  8. Evaluación del efecto genotóxico y la susceptibilidad individual por exposición a plomo ambiental en la vereda la Bonga, Atlántico, Colombia

    OpenAIRE

    Vergara García, Ángela Patricia

    2014-01-01

    El plomo es un metal pesado no esencial para la vida, bioacumulable y persistente en el medio ambiente. Este interactúa con el ADN generando dobles enlaces o aductos, rupturas de cadena simple, doble y mutagénesis. En este estudio se evaluaron niveles de plomo en sangre (biomarcador de exposición), daño en el ADN mediante el ensayo cometa y el test de micronúcleos (biomarcador de efecto) y polimorfismos del gen ALAD (biomarcador de susceptibilidad) en 59 individuos expuestos ambientalmente a ...

  9. Determinación de plomo en diversos tejidos de animales suplementados oralmente con cieno de acetileno (cenizas de carburo) por períodos de tiempo prolongados

    OpenAIRE

    Hernández Barreto, Miguel A; García Díaz, Pedro; Sánchez Álvarez, Carmen; Brito Alberto, Elio; Rodríguez Jiménez, Livia

    2005-01-01

    Se realizaron determinaciones de plomo a partir de 11 muestras de sangre y 20 de leche procedentes de hembras bovinas que habían sido suplementadas oralmente con Cieno de Acetileno a razón de 140 g diarios mezclados con melaza de caña. De igual forma, se realizaron determinaciones de ese metal pesado a partir de muestras de sangre, hígado, muslo y pechuga de 6 gallinas reproductoras que recibieron unos 3,3 g diarios del residual industrial mezclado con el pienso durante más de 90 días. En el ...

  10. LÍMITES PERMISIBLES DE ACUMULACIÓN DE CADMIO, NÍQUEL Y PLOMO EN SUELOS DEL VALLE DEL MEZQUITAL, HIDALGO

    OpenAIRE

    Antonio Vázquez-Alarcón; Lenom J. Cajuste; Rogelio Carrillo-González; Benjamín Zamudio-González; Edna Álvarez-Sánchez; Javier Z. Castellanos-Ramos

    2005-01-01

    En México, se carece de información relativa a la calidad de suelos en términos del contenido de metales pesados. Los datos disponibles corresponden a información generada en otros países, extrapolada a los suelos nacionales. Con el presente estudio se trata de realizar una aproximación a los valores de referencia de acumulación de cadmio, níquel y plomo en suelos. La metodología consistió en resolver un modelo que relaciona el límite permisible de acumulación con variables como dosis de inge...

  11. Structural relationship between one-dimensional crystals of Guinier-Preston-Bagaryatsky zones in Al-Cu-Mg alloys

    International Nuclear Information System (INIS)

    Highlights: → This work identifies and fully describes a new type of 1D-crystalof the GPB zone family based on high-resolution Scanning TransmissionElectron Microscopy. → The observations enable to generalize the relationship between the1D crystals of GPB zones. → Ab-initio calculations show that the newly identified 1D-crystalhas a formation energy that is comparable to the larger GPB zonescrystals. -- The crystal structure of Guinier-Preston-Bagaryatsky (GPB) zones in Al-Cu-Mg alloys is unique, consisting of agglomerated one-dimensional (1D) crystals. This work identifies and fully describes a new type of 1D crystal of the GPB zone family based on high-resolution scanning transmission electron microscopy. The observation enables the structural relationship between the possible 1D crystals to be generalized. Ab initio calculations show that the newly identified 1D crystal has a formation energy that is comparable to larger types, and much more favorable than face-centered-cubic-based models.

  12. A 1500 yr warm-season temperature record from varved Lago Plomo, Northern Patagonia (47° S) and implications for the Pacific Decadal Oscillation (PDO)

    Science.gov (United States)

    Elbert, J.; Jacques-Coper, M.; Van Daele, M.; Urrutia, R.; Grosjean, M.

    2013-04-01

    High-resolution records of calibrated proxy data for the past 2000 yr are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and South America. We provide a 1500 yr long warm season temperature record from varved Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in southern Chile (46°59' S, 72°52' W, 203 m). The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400-730 nm) is calibrated against warm season SONDJF temperature (1900-2009; r = 0.58, p(aut) = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data). In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in a thicker light summer layer and to brighter sediments (% total brightness). Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 1500 yr temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records but also emphasizes significant regional differences for which no data and information existed so far. The reconstruction shows pronounced sub-decadal-multi-decadal variability with cold phases in the 5th, 7th and 9th centuries, during parts of the Little Ice Age chronozone (16th and 18th centuries) and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century, emphasizing a delayed recent global warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling) from Lago Plomo reveals alternating phases with parallel and

  13. A 1500 yr warm-season temperature record from varved Lago Plomo, Northern Patagonia (47° S and implications for the Pacific Decadal Oscillation (PDO

    Directory of Open Access Journals (Sweden)

    J. Elbert

    2013-04-01

    Full Text Available High-resolution records of calibrated proxy data for the past 2000 yr are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and South America. We provide a 1500 yr long warm season temperature record from varved Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in southern Chile (46°59' S, 72°52' W, 203 m. The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400–730 nm is calibrated against warm season SONDJF temperature (1900–2009; r = 0.58, p(aut = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data. In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in a thicker light summer layer and to brighter sediments (% total brightness. Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 1500 yr temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records but also emphasizes significant regional differences for which no data and information existed so far. The reconstruction shows pronounced sub-decadal–multi-decadal variability with cold phases in the 5th, 7th and 9th centuries, during parts of the Little Ice Age chronozone (16th and 18th centuries and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century, emphasizing a delayed recent global warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling from Lago Plomo reveals alternating phases with

  14. The Relationship between Language Functions and Character Types in Noon val-Ghalam by Jalal Al Ahmad

    Directory of Open Access Journals (Sweden)

    Sayyed Ahmad Parsa

    2013-11-01

    Full Text Available Abstract Making harmony among language functions of story characters with their character types is one of the characteristics and advantages of modern and successful story writing. In traditional fictional literature in Iran (prose and verse, this point is not considered important and story characters, generally, speak in the voice of narrator or writer since there is the narrators statement on their speech, they are not the representative of their class and character type. Not paying attention to this subject, causes disorder in either making supposition of reality or personifying, which are both important principals of story telling. This study views from this point the story of Noon val-Ghalam of Jalal Al Ahmad who is a contemporary writer. The methodology is qualitative, and data collection is based on content–analysis and document- analysis. As Al Ahmad was one of the Iranian contemporary writers and was familiar with western and Iranian writers, it is expected that the language and way of describing story characters he made, be based on their social classes. But this study, by stating different proofs, shows that this writer ignores the relationship necessary for language functions and character type among characters in the story and because of the imposition of his knowledge, statement and political and social view, the independence of the protagonists in his story is not well-considered.  The inflection of political and social thoughts of each writer among his works, is not a shortfall by itself, but representing of speeches in protagonists, in the way which is not in harmony with their characters, underestimates them as an instrument for specific social and political representatives. This not only displays the character like a personified ideas, but also distructs processing of fictional dialogue as an important element in storytelling . Since in each language people from different social groups, use almost the same vocabularies that

  15. Mecanismos de movilidad de dislocaciones a temperaturas medias en plomo de muy alta pureza (99.9999 %

    Directory of Open Access Journals (Sweden)

    Gallego, I.

    1998-05-01

    Full Text Available The internal friction spectrum of high purity lead (99.9999 % at medium temperatures has been studied. A new peak (P1 has been found at 240 K, which has not been studied up to now. The activation energy of the process associated with F, has been determined and its experimental behaviour has also been systematically studied. The comparison between the results and the theoretical predictions of the models of dislocation mobility allows us to attribute the P1 peak to the sliding of dislocations, controlled by the climbing of jogs induced by the diffusion of vacancies along the dislocation line. This conclusion is analogue to that obtained in previous works for the P1v peak in very high purity aluminium (99.9999 %.

    Se ha realizado un estudio sistemático del espectro de fricción interna del plomo de muy alta pureza (99,9999 % a temperaturas medias, encontrándose un pico a 240 K (P1 que no ha sido estudiado en la bibliografía hasta el momento. Los análisis mediante fricción interna nos han permitido evaluar la energía de activación del proceso ligado a P1 y determinar el comportamiento de este pico en función de diversos parámetros. La comparación de los resultados experimentales con las predicciones teóricas de varios modelos microscópicos de movilidad de dislocaciones nos ha permitido concluir que el pico P1 está asociado con el deslizamiento de dislocaciones controlado por la escalada de escalones mediante la difusión de vacantes a lo largo de, la línea de dislocación. Esta interpretación es análoga a la realizada en trabajos previos para el pico P1 del aluminio de muy alta pureza (99,9999 %.

  16. The relationship between the hardness and the point-defect-density in neutron-irradiated MgO{center_dot}3.0Al{sub 2}O{sub 3} and AlN

    Energy Technology Data Exchange (ETDEWEB)

    Suematsu, H.; Yatsui, K. [Nagaoka Univ. of Technology, Extreme Energy-Density Research Institute, Nagaoka, Niigata (Japan); Yano, T. [Tokyo Institute of Technology, Research Laboratory for Nuclear Reactors, Tokyo (Japan)

    2001-09-01

    MgO{center_dot}3.0Al{sub 2}O{sub 3} single crystals and sintered AlN polycrystals were irradiated with fast neutrons in various conditions and the hardness of the irradiated and unirradiated samples was measured with a Vickers hardness tester. The hardness of as-irradiated MgO{center_dot}3.0Al{sub 2}O{sub 3} and AlN samples increased by 23 and 51%, respectively. After isochronal annealing, the hardness gradually decreased and mostly recovered to that of the unirradiated one up to 1400degC. Volume of the sample also increased after the irradiation and changed in the same way as the hardness by annealing. A relationship between the hardness and the density of point defects is proposed and the experimental results agree with the relationship. It implies that the point defects generated by the irradiation pin down dislocations and increase the hardness of neutron irradiated MgO{center_dot}3.0Al{sub 2}O{sub 3} samples. (author)

  17. Orientation relationship between alpha-prime titanium and silicide S2 in alloy Ti-6Al-5Zr-0. 5Mo-0. 25Si

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandra, C.; Singh, V.

    1985-03-01

    Orientation relationships between the silicide S2 and the matrix of alpha-prime platelets are established for the titanium alloy 685 (Ti-6Al-5Zr-0.5Mo-0.25Si), a near-alpha alloy designed for the high-temperature components of jet engines. A stereogram showing the parallel planes of alpha-prime and S2 is presented for the alloy in the water-quenched and aged condition. A table is also presented which lists the parallel planes of the matrix and the silicide along with the misfit parameters. The results obtained are compared with the orientation relationships reported in the literature. 14 references.

  18. EVALUACIÓN ECONÓMICA DEL IMPACTO DE LA PROHIBICIÓN DE PLOMO EN LAS GASOLINAS EN EL COCIENTE INTELECTUAL DE LOS NIÑOS DE 7 Y 8 AÑOS DE LA COMUNIDAD DE MADRID

    Directory of Open Access Journals (Sweden)

    José Mª Ordóñez-Iriarte

    2015-01-01

    Full Text Available Fundamentos:La evaluación económica de las repercusiones sanita-rias de las políticas públicas es difícil y escasa. El objetivo del presente estu-dio fue cuantificar monetariamente los beneficios de la reducción del plomoen la sangre de los niños de 7-8 años en la Comunidad de Madrid (España,derivada de la prohibición del plomo en las gasolinas.Métodos:Se calculó la disminución de puntos de cociente intelectual(CI, utilizando dos estudios realizados en niños de 7 a 8 años según losvalores de plomo en sangre que presentaban: media geométrica de 3,8 μg/dL en 1995 y 0,9 μg/dL en 2010. La mejoría neta de CI se midió en términosde capacidad de producción ganada a lo largo de la vida laboral, siguiendolos métodos de Schwartz y Salkiver.Resultados:La reducción de los niveles de plomo en sangre de estosniños evitó perder entre 135.391 y 144.153 puntos de CI. La valoracióneconómica actual de estos puntos en términos de capacidad de producciónganada a lo largo de la vida laboral de estos sujetos se estimó en un rangoentre 626,4 y 865,4 millones de euros (valor 2009.Conclusiones:Las cifras de beneficios económicos encontradas deri-vadas de la medida de prohibición de uso de plomo en las gasolinas sonimportantes en términos sociales.

  19. Prácticas y Cambios Contables en la Minería del Plomo de la Carolina (Jaén: Estudio de la Empresa Minera el Guindo en los Años Finales del S. XIX y Primer Cuarto del S. XX

    Directory of Open Access Journals (Sweden)

    José M.ª Carlos Álvarez López

    2006-06-01

    Full Text Available Hemos investigado sobre los libros contables de la sociedad minera El Guindo (sucursal de la Carolina, situada en el sur de España y dedicada a la extracción de plomo, con el fin de examinar sus prácticas contables y los avances producidos en ellas. Destacamos, como cambios esenciales, en el primer periodo analizado (1899-1925, el paso del criterio de caja al criterio de devengo en los libros principales y, fundamentalmente, la introducción de un criterio de valoración para minerales basado en precios de mercado. Considerando que la admisión a cotización en Bolsa en 1921 fue el hecho más determinante de dichos cambios.With the aim of examining accounting practices and the progress made in this field, we have investigated the accounts books of the mining company El Guindo situated in the south of Spain (the branch in La Carolina, which dealt in the business of the extraction of lead. During the first period analyzed (1899-1925 the most notable changes were the move from a cash-based accounting system to an accrual-based accounting system in the main books and, fundamentally, the introduction of an valuation criterion for minerals based on market prices. Considering the most significant factor that gave rise to these changes to be its listing on the Stock Market in 1921.

  20. El estrés oxidativo como mecanismo de acción del plomo: Implicancias terapéuticas Oxidative stress as a mechanism of action of lead: Therapeutic implications

    Directory of Open Access Journals (Sweden)

    Samanta Andrea Martínez

    2011-12-01

    Full Text Available El plomo (Pb es un metal no esencial altamente tóxico que afecta a diversos órganos y tejidos. Si bien aún no ha sido descripto un mecanismo único mediante el cual este metal ejerce sus efectos tóxicos, un gran número de estudios han puesto en evidencia el rol fundamental del estrés oxidativo en la intoxicación por Pb. A este respecto, ha sido informado que en la intoxicación por Pb el estrés oxidativo puede ocurrir a diferentes niveles: por generación de ácido ä-aminolevulínico (ä-ALA, por la capacidad per se que posee el Pb para inducir peroxidación lipídica en presencia de ión ferroso (Fe2+, o por depleción de glutatión (GSH y enzimas antioxidantes. Sobre la base de estos antecedentes, el objetivo de esta revisión es presentar evidencias recientes sobre la implicancia del estrés oxidativo en los efectos adversos ocasionados por Pb, destacar la posibilidad de utilización de biomarcadores de estrés oxidativo como un método complementario al diagnóstico temprano de exposición y revelar la importancia de los compuestos antioxidantes como nuevas herramientas en la prevención y tratamiento de la intoxicación por este metal.Lead (Pb is a highly toxic non-essential metal that affects different organs and tissues. Although at the present a unique mechanism by which this metal exerts its toxic effects has not been described, a large number of studies have highlighted the fundamental role of oxidative stress in the pathophysiology of Pb poisoning. In this regard, it has been reported that Pb-induced oxidative stress can occur at different levels: by the generation of ä-aminolevulinic acid (ä-ALA, through its ability to induce lipid peroxidation in the presence of ferrous ion (Fe2+, or via glutathione (GSH or antioxidant enzyme depletion. On the basis of these antecedents, the aim of this review is to present recent evidence regarding the implication of oxidative stress in the adverse effects caused by Pb, to emphasize the

  1. Relationship between CO2 Sensor Voltage Response and Phase Equilibrium of Solid Electrolyte Na, K-β/β"-Al2O3

    Institute of Scientific and Technical Information of China (English)

    J.H. YANG; H.N(a)fe; F. Aldinger; D.S. YAN

    2003-01-01

    A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2,CO2|Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell Ⅱ: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt.(Na,K-β/β″-Al2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region ofphase equilibrium for Na, K-β/β"-Al2O3 material. The relationship between CO2 sensor voltage response and phaseequilibrium of solid electrolyte Na, K-β/β-Al2O3 is discussed in this paper.

  2. Microstructural Evolution and Structure-Hardness Relationship in an Al-4wt.%Mg Alloy Processed by High-Pressure Torsion

    Science.gov (United States)

    Yang, Xiaohui; Yi, Jianhong; Ni, Song; Du, Yong; Song, Min

    2016-05-01

    Coarse-grained Al-4wt.%Mg alloy with high stacking fault energy was deformed by high-pressure torsion (HPT) at room temperature. The HPT-induced grain refinement process of the alloy can be clarified as follows: (1) the randomly distributed dislocations firstly interact and rearrange to form dislocation cells; (2) with increasing the strain, these cell boundaries transform to small-angle grain boundaries that act as the dislocation sources, and therefore Shockley partial dislocations on the glide plane (111) can be easily emitted to accommodate plastic deformation; (3) along with the partial dislocations emission from low angle grain boundaries, the low angle grain boundaries gradually transform into the high angle grain boundaries. The relationship between the microstructural evolution and hardness was also investigated. It has been shown that the relationship between grain size and hardness deviates from the Hall-Petch linear relationship.

  3. [Research on the Relationship between Surface Structure and Fluorescence Intensity of Ca(1-x)Al2Si2O8 : Eu(x)].

    Science.gov (United States)

    He, Xiao; Zhang, Li-sheng; Zu, En-dong; Yang, Xiao-yun; Dong, Kun

    2016-01-01

    Ca(1-x)Al2Si2O8 : Eu(x)(x = 0, 0.01, 0.05, 0.15) were synthesized by solid-state reaction respectively at 1 150, 1 250 1350 and 1 450 degrees C. With X-ray diffraction(XRD), Raman spectroscopy(Raman), photoluminescence spectroscopy(PL) and X-ray fluorescence spectrometer(XRF), the relationship between surface structure and fluorescence intensity of Ca(1-x) Al2Si2O8: Eu(x) were studied. XRD and Raman results show that, CaAl2Si2O8 anorthite single-phase has formed gradually along with the temperature rising in the process of synthesis. Raman spectroscopy is clear that when the Eu doping amount is the same, Si-O amorphous phase disappear gradually and the CaAl2Si2O8 phase form gradually with the temperature increases. As the temperature increases, vibration peaks position silicon oxygen tetrahedron shift to lower wave number. When 1 450 degrees C, the temperature is too high to destroy the structure of silicon oxygen tetrahedron. At the same time, there is a broadening amorphous peak appears in Raman spectroscopy. The procedure of Al to replace Si is hindered with Eu doped in. It is the result that the peak at 1 620 cm(-1) decreases after the first increases. The change of surface structure associated with the scattering amount of Eu. PL and XRF results show that: as the temperature increases, the amount of Eu atom scattering on the material surface increases gradually, this change lead to the fluorescence intensity raise. Therefore, there is proportional relationship between the fluorescence intensity of the samples and the number of samples per unit surface area of Eu atoms. PMID:27228758

  4. Chemical speciation of dissolved lead in polluted environments. A case of study: the Pontevedra Ria (NW Spain); Especiacion quimica del plomo disuelto en ambientes contaminados. Caso de estudio: la Ria de Pontevedra (NO de Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Cobelo-Garcia, A.; Prego, R. [Grupo de Biogeoquimica Marina, Instituto de Investigaciones Marinas IIM-CSIC, Vigo (Spain); Nieto, O. [Departamento de Quimica Analitica y Alimentaria, Facultad de Ciencias, Universidad de Vigo, Vigo (Spain)

    2003-10-15

    Chemical speciation of dissolved lead was determined at four sampling sites in the Pontevedra Ria (NW Spain) by differential pulse anodic stripping voltammetry (DPASV) with a HMDE. Sampling location was chosen due to its evident anthropogenic influence: one sample was taken in the Lerez River mouth (2.2-salinity) and other three samples were taken in the surroundings of the village of Marin (salinity 30-32). Lead concentrations were 0.64 nM (river sample) and 4.8-21.9 nM (saline samples). Speciation results showed that organic chelates of lead, 88-95% of total dissolved lead, are the dominant species of the metal even at these high concentrations. Two types of lead organic complexing ligands were detected in all samples. The river water sample showed the presence of a strong ligand with a concentration of {approx} 7 nM with a conditional stability constant of K'{sub P}b-L1 {>=} 10{sup 1}1.1, and a weaker ligand (K'{sub P}b-L2 = 10{sup 8}.2) with a concentration of 53.4 nM. The three saline samples showed similar behavior: a strong ligand (K'{sub P}b-L1 {approx} 10{sup 8}.6) with concentration ranging from 33.0 to 53.5 nM, and a weaker complexing ligand (K'{sub P}b-L2 {approx} 10{sup 7}.5) with concentration ranging from 32.6 to 50.5 nM. All lead-organic ligand complexes (except the strong complex in the river water sample) showed labile behavior in the time scale of the technique. [Spanish] La especiacion quimica del plomo disuelto se llevo a cabo en cuatro estaciones de muestreo en la Ria Pontevedra (NO de Espana) utilizando la tecnica de voltametria de redisolucion anodica de pulso diferencial (DPASV) con un HMDE. La zona de muestreo fue elegida en base a su clara influencia antropogenica: se tomo una muestra en la desembocadura del Rio Lerez (salinidad 2.2) y las otras tres se tomaron en las proximidades de la Villa de Marin (salinidad 30-32). Las concentraciones de plomo obtenidas fueron de 0.64 nM (muestra de agua dulce) y 4.8-2.9 n

  5. Exposición a plomo en niños de 6 a 12 años de edad Lead exposure in children from 6 to 12 years old

    Directory of Open Access Journals (Sweden)

    Carlos Jiménez-Gutiérrez

    1999-11-01

    Full Text Available Objetivo. Identificar los factores de exposición asociados a las concentraciones de plomo en niños de escuelas primarias públicas y privadas de la ciudad de México. Material y métodos. Se realizó un estudio transversal en 340 niños que asistían a la escuela primaria. Las escuelas se seleccionaron por conveniencia y los niños en forma aleatoria. Se aplicó un cuestionario y se tomaron muestras de sangre venosa. Los niveles de plomo se determinaron por espectrofotometría de absorción atómica. Se compararon medias mediante la prueba t de Student-Fisher y ANDEVA; y para el análisis multivariado, regresión lineal múltiple. Debido a que los niveles de plomo no seguían una distribución normal, se transformó con logaritmo neperiano, con la que se trabajó en todo el análisis estadístico. Resultados. Las medias geométricas para escuelas privadas y públicas fueron: MG=8.76 µg/dl, IC95%=9.1-10.5; MG=11.5 µg/dl, IC95%=9.4-13.5, respectivamente. Los niveles de plomo son más elevados en los niños que asisten a la escuela pública y que presentan las siguientes características: ser varones, tener entre seis y ocho años de edad y cursar el primer o segundo grado de primaria; las madres de estos niños son profesionistas; en sus hogares se utiliza la cerámica vidriada y cerca de sus domicilios existen diferentes tipos de talleres contaminantes con plomo. Conclusiones. Los factores de exposición que predicen las concentraciones de plomo en sangre son: tener entre seis y ocho años de edad, la ocupación de la madre, la utilización de cerámica vidriada, la cercanía de diferentes tipos de talleres contaminantes con plomo a los domicilios y cursar el segundo año de primaria.Objective. To identify exposure factors contributing to lead poisoning in school children from Mexico City. Material and methods. Cross-sectional study of 340 children. A convenience sample of schools and a random sample of children were selected. A questionnaire

  6. Cuantificación de plomo, cadmio y cromo mediante sialoquímica Quantification of lead, cadmium and chromium through sialochemistry

    Directory of Open Access Journals (Sweden)

    MIREYA GONZÁLEZ

    1997-05-01

    Full Text Available Objetivo. Determinar las concentraciones de plomo, cadmio y cromo, y establecer su posible asociación con diferentes factores sociodemográficos. Material y métodos. Se seleccionó una muestra representativa de 100 estudiantes de posgrado de la Facultad de Odontología de la Universidad Nacional Autónoma de México (UNAM, a los cuales se les colectó saliva total no estimulada. Dichas muestras fueron analizadas por espectrofotometría de absorción atómica con horno de grafito. Resultados. Metales pesados como el plomo, el cadmio y el cromo se encuentran en concentraciones mucho más altas que las informadas en la literatura: Pb, = 3.10 m g/dL-1, máxima: 16.8 my g/dL-1, y mínima: 0.04 my g/dL-1; Cd, = 0.25 my g/dL-1, máxima: 2.04 my g/dL-1, y mínima: 0.004 my g/dL-1; y Cr, = 1.43 my g/dL-1, máxima: 4.82 my g/dL-1, y mínima: 0.05 my g/dL-1. Asimismo, variables como la zona de residencia, el sexo, la edad y la ingesta de comida enlatada no influyen en los niveles de plomo y cromo. Sin embargo, en el caso del cadmio y la edad existe una asociación inversa (ji²= 5.9012, pObjective. To determine the concentration of lead (Pb, cadmium (Cd, and chromium (Cr and establish the possible association of these heavy metals with some sociodemographic factors. Material and methods. A representative sample of one hundred dental students from the National Autonomous University of Mexico living in Mexico City participated in this study. Unstimulated human whole saliva samples were analyzed by Atomic Absorption Spectroscopy. Results. Concentrations of Pb, Cd, and Cr were higher than those reported elsewhere: Pb ( or = 3.10 m g/dL-1; Maximum: 16.8 mu g/dL-1 and Minimum: 0.04 mu g/dL-1, Cd ( or = 0.25 mu g/dL-1; Maximum: 2.04 mu g/dL-1 and Minimum: 0.004 mu g/dL-1 and Cr ( or = 1.43 mu g/dL-1; Maximum: 4.82 mu g/dL-1 and Minimum: 0.05 mu g/dL-1. No association was found between the variables studied (age, sex, geographic area and canned food consumption

  7. Relationship between Leucite Content and Compressive Strength of K2O-Al2O3-SiO2 System Dental Glass Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Biao; QIAN Fatang; DUAN Xinglong; WU Bolin

    2009-01-01

    Relationship between leucite content and compressive strength of K2O-Al2O3-SiO2 sys-tem dental glass ceramics were investigated. 10 groups of feedstock powder with different composi-tions were treated according to the same thermal treatment system of leucite micro-crystallization reported in some primary studies. The products of each group were analyzed by X-ray diffractometer,polaring microscope and scanning electronic microscope (SEM), and then the compressive strength was tested by a material testing machine. A direct proportion was found between leucite content and the compressive strength when leucite content was less than 50 vol%, and compressive strength de-creased with the increasing of leucite micro-crystals when leucite content was more than 50vol%, The leucite content has a notable influence on the compressive strength of K2O-Al2O3-SiO2 system dental glass ceramics.

  8. Relationship between columnar crystal spacing and electric current density in unidirectional solidification of monophase Cu-Al alloy

    Institute of Scientific and Technical Information of China (English)

    常国威; 曹丽云; 袁军平; 王自东; 吴春京; 胡汉起

    2002-01-01

    On the basis of previous theoretical inferential relationship between the columnar crystal spacing and the density of electric current applied during unidirectional solidification, the effect of current density on the columnar crystal spacing was discussed and analyzed, and the experiment was made to verify the theoretical relationship. The results show that at fast solidification speed the columnar crystal spacing decreases with increasing the density of electric current, while at slow solidification speed the columnar crystal spacing increases with increasing the density of electric current. The critical conditions for the evolution of columnar crystal spacing were confirmed. The calculated values concerning the spacing and the density are consistent with the experimental results.

  9. Design, synthesis and bioactivity of novel ALS enzyme inhibitors (II)——Molecular mechanics, quantum chemistry and structure-activity relationship studies on the herbicidal heterocyclic sulfonamide

    Institute of Scientific and Technical Information of China (English)

    陆荣健; 杨华铮; 尚贞锋; 汪惟为; 潘荫明; 赵学庄

    1996-01-01

    In view of quantum pharmacology, the structure-activity relationships of different kinds of fused heterocydic sulfonamides with the same mode of action were first investigated using molecular mechanics, quantum chemistry and discriminatory analysis. It has been found that the process of the interaction of the fused heterocydic sulfonamide with ALS enzyme involves the electropositive region of the sulfonyl bridge chain and the electronegative region of the heterocydic moiety. The herbicidal activity is related to the potency of electric charge translocation of the related regions.

  10. Remoción de plomo (II usando lignina obtenida a partir del procesamiento del seudotallo de plátano

    Directory of Open Access Journals (Sweden)

    José Herney Ramírez Franco

    2015-07-01

    Full Text Available Se evaluó la adsorción de iones plomo (Pb2+ sobre lignina recuperada del licor residual generado en el proceso de producción de papel a partir de seudotallos (vástago de plátano. La eficiencia de recuperación encontrada fue de aproximadamente 82%. La lignina fue caracterizada mediante espectroscopia de infrarrojo con el objeto de identificar sitios activos adecuados para el proceso de adsorción de metales pesados. Sus características de superficie se determinaron mediante isotermas de adsorción - desorción de nitrógeno (N2. La lignina recuperada después de su uso en adsorción mostró un área superficial de 840 m²/g y un volumen total de poros de 0.30 cm³/g. Para evaluar la capacidad de adsorción de la lignina respecto de la concentración inicial de los iones, se prepararon soluciones de Pb2+ 0.6, 0.8 y 1.0 mM. Finalmente, se determinó la concentración final de Pb2+ por medio de espectroscopia de absorción atómica, encontrando remociones de 55%

  11. Low Blood Lead Levels and educational achievement in 7-8 year old children in the Community of Madrid (Spain Bajos niveles de plomo en sangre y rendimiento escolar en niños de 7-8 años en la Comunidad de Madrid (España Baixos níveis de chumbo no sangue e sucesso escolar nas crianças entre os 7-8 anos na Comunidade de Madrid (Espanha

    Directory of Open Access Journals (Sweden)

    María José Martínez García

    2013-06-01

    rendimiento académico de los niños. Los padres rellenaron a su vez una encuesta relativa a las variables sociodemográficas de los niños y su familia.Resultados: El nivel medio de plomo en sangre fue de 4,1 μg/dL DE 1,6 μg/dL (log transformado 3,8 μg/dL, DE 0,2 μg/dL. El análisis multivariado controlando por cofactores sociodemográficos relevantes (entre otros, sexo, edad y nivel de educación de los padres mostró una asociación negativa, pero sin significación estadística.Conclusiones: A pesar de las bajas concentraciones de plomo encontradas en la sangre de los niños de la Comunidad de Madrid y de las limitaciones del diseño, los resultados obtenidos sugieren la existencia de un efecto nocivo del plomo en sangre sobre la conducta y el rendimiento académico de los niños, no significativo.Enquadramento: O chumbo afeta as funções comportamentais e cognitivas das crianças. Não há consenso acerca do atual nível de segurança do chumbo que visa evitar estes efeitos adversos.Métodos: Estudo transversal com 511 crianças de 23 escolas primárias da Comunidade de Madrid, Espanha (Região de Madrid -incluindo a cidade de Madrid e a aglomeração urbano-industrial das cidades satélites que a rodeiam. O nível de chumbo no sangue das crianças foi determinado por espectrofotometria de absorção atómica. Além disso, os professores responderam a um questionário de oito itens sobre o comportamento das crianças e desempenho escolar. Os pais preencheram um questionário sobre as variáveis sociodemográficas das crianças e da família.Resultados: O nível médio de chumbo no sangue das crianças foi de 4,1 μg/dL SD 1,6 μg/dL (log transformado 3,8 μg/dL SD 0,2 μg/ dL. A análise multivariada controlada pelas variáveis sociodemográficas (idade, sexo e nível de escolaridade dos pais, entre outros mostrou uma associação negativa, mas esta não foi estatisticamente significativa.Conclusões: Apesar dos baixos níveis de chumbo encontrados no sangue das

  12. Niveles de plomo sanguíneo en madres y recién nacidos derechohabientes del Instituto Mexicano del Seguro Social Blood lead levels in newborn children and mothers covered by the Mexican Institute of Social Security

    Directory of Open Access Journals (Sweden)

    Joel Navarrete-Espinosa

    2000-09-01

    Full Text Available OBJETIVO: Establecer la relación entre el nivel de plomo sanguíneo materno (PSM y el de sangre en cordón umbilical (PSC al momento del parto, así como determinar los principales predictores del PSM en derechohabientes del Instituto Mexicano del Seguro Social (IMSS, en el Distrito Federal (D.F.. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en el que se reclutaron voluntarias con embarazo normoevolutivo y se les tomaron muestras de sangre al momento del parto, en cuatro hospitales del IMSS en el D.F., de 1991 a 1993. Se tomó, además, muestra de sangre de cordón umbilical. Los datos fueron analizados mediante regresión lineal simple y múltiple. RESULTADOS: Se estudiaron un total de 1 404 binomios madre-hijo; el promedio de edad de las madres fue de 25 años. La media de PSM fue 10.7 ± 6.5 µg/dl; no se encontraron variaciones significativas por hospital, edad o estado civil. Para el PSC la media fue de 10.4 ± 6.2 µg/dl. Por cada aumento en una unidad logarítmica de PSM, el PSC aumenta 0.62 (pOBJECTIVE: To establish the relation between maternal blood lead (MBL and umbilical cord blood lead (CBL levels during delivery, and to determine the major predictors for MBL in women covered by the Mexican Institute of Social Security (MISS, in Mexico City. MATERIAL AND METHODS: From 1991 to 1993, a cross-sectional study was conducted in four MISS hospitals, among normal pregnant women who volunteered to participate. Blood samples were taken from women and from the umbilical cord during delivery. Statistical analysis consisted of descriptive statistics and simple and multiple linear regression. RESULTS: A total of 1 404 mother-newborn pairs were studied. Mean maternal age was 25 years. MBL average was 10.7 ± 6.5 µg/dl; no significant differences were found by hospital, age, or marital status. Mean CBL was 10.4 ± 6.2 µg/dl. A log unit increase in MBL corresponded to a log increase of 0.62 in CBL (p< 0.01. Pearson's correlation was 0

  13. Complex structure/composition relationship in thin films of AlCoCrCuFeNi high entropy alloy

    International Nuclear Information System (INIS)

    We have studied the deposition of AlCoCrCuFeNi high entropy alloy (HEA) thin films on Si (1 0 0) substrates by DC magnetron sputtering process. Three mosaic targets have been used for easily tailoring the film composition. Energy dispersive X-ray spectrometry analysis has shown that chemical composition can be modified around the nominal value by tuning the ratio of the powers applied to the magnetron targets. The deposition rate is directly related to the power sum. Moreover, various surface morphologies have been evidenced by scanning electron microscopy and correlated to the crystalline phases present in the films. Morphology and crystalline structure have been found to depend on the chemical composition. Wetting contact angle has been measured with water droplets, showing that the hydrophobic properties of the thin films depend on their characteristics.

  14. Temporal trending of lead and cadmium contamination in the Vigo estuary intertidal area Evolución temporal de la contaminación por plomo y cadmio en la zona intermareal de la ría de Vigo

    Directory of Open Access Journals (Sweden)

    J. Alonso Díaz

    2004-12-01

    Full Text Available At the present work, limpet (Patella vulgata L. and seaweed (Ulva lactuca specimens have been monthly sampled at the same point from the Vigo estuary, during a year. Heavy metal (cadmium and lead content has been determined by means of differential pulse anodic stripping voltammetry in both limpet and seaweed tissues, as well as in seawater. The obtained results have shown the main heavy metal content in limpet soft tissues with respect to shell, with maximum concentrations of 3 ppm (limpet shell for lead, whereas the highest content for cadmium was identified in seaweed samples (1.1 ppm. The statistical study revealed the existence of a clear correlation between cadmium and lead concentrations in seaweed samples.En el presente trabajo se han recogido muestras de lapa (Patella vulgata L. y alga verde (Ulva lactuca en un mismo punto de muestreo de la ría de Vigo, con una periodicidad mensual, a lo largo de un año, analizándose por medio de voltamperometría de redisolución anódica la concentración en dos metales pesados con claras repercusiones toxicológicas, cadmio y plomo, en estas muestras, así como en el agua marina. Los resultados obtenidos mostraron la mayor concentración de ambos metales en los tejidos blandos de las lapas frente a las valvas de estos moluscos, con valores máximos en el caso del plomo próximos a 3 ppm (valva de lapa, mientras que para el cadmio se situó en torno a 1,1 ppm (alga verde. El estudio estadístico permitió poner en evidencia una clara correlación estadística entre los valores de cadmio y plomo cuantificados en las muestras de algas.

  15. Structure-property relationships in an Al matrix Ca nanofilamentary composite conductor with potential application in high-voltage power transmission

    Science.gov (United States)

    Tian, Liang

    This study investigated the processing-structure-properties relationships in an Al/Ca composites using both experiments and modeling/simulation. A particular focus of the project was understanding how the strength and electrical conductivity of the composite are related to its microstructure in the hope that a conducting material with light weight, high strength, and high electrical conductivity can be developed to produce overhead high-voltage power transmission cables. The current power transmission cables (e.g., Aluminum Conductor Steel Reinforced (ACSR)) have acceptable performance for high-voltage AC transmission, but are less well suited for high-voltage DC transmission due to the poorly conducting core materials that support the cable weight. This Al/Ca composite was produced by powder metallurgy and severe plastic deformation by extrusion and swaging. The fine Ca metal powders have been produced by centrifugal atomization with rotating liquid oil quench bath, and a detailed study about the atomization process and powder characteristics has been conducted. The microstructure of Al/Ca composite was characterized by electron microscopy. Microstructure changes at elevated temperature were characterized by thermal analysis and indirect resistivity tests. The strength and electrical conductivity were measured by tensile tests and four-point probe resistivity tests. Predicting the strength and electrical conductivity of the composite was done by micro-mechanics-based analytical modeling. Microstructure evolution was studied by mesoscale-thermodynamics-based phase field modeling and a preliminary atomistic molecular dynamics simulation. The application prospects of this composite was studied by an economic analysis. This study suggests that the Al/Ca (20 vol. %) composite shows promise for use as overhead power transmission cables. Further studies are needed to measure the corrosion resistance, fatigue properties and energized field performance of this composite.

  16. Estudios de bioacumulación de un metal de interés en contaminación ambiental (plomo) en larvas de lubina de gran valor comercial

    OpenAIRE

    Coto Reyes, José Óscar

    2015-01-01

    La contaminación por metales pesados es uno de los mayores problemas ambientales en la actualidad debido a su alto grado de persistencia en el medio y su tendencia a la bioacumulación en la cadena trófica, por lo que son considerados un riesgo importante para los seres vivos. Estos metales, entre los que destaca el plomo, son considerados extremadamente peligrosos para la vida dada su elevada toxicidad incluso a bajas concentraciones. Por ello, en el presente trabajo de fin de grado, se p...

  17. Niveles de plomo en sangre en niños de 8 a 10 años y su relación con la alteración en el sistema visomotor y del equilibrio

    OpenAIRE

    Azcona-Cruz María Isabel; Rothenberg Stephen J.; Schnaas-Arrieta Lourdes; Romero-Placeres Manuel; Perroni-Hernández Estela

    2000-01-01

    OBJETIVO: Identificar si existe una asociación negativa entre los niveles de plomo en sangre y la coordinación visomotora y el equilibrio de escolares. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en 255 niños de 8 a 10 años de edad, que asistían a escuelas del Sector 1 del Instituto de Educación Pública del Estado de Oaxaca, durante noviembre y diciembre de 1998. Se les aplicaron las pruebas de evaluación de la percepción visual de Frostig y la subescala de equilibrio Frostig Moveme...

  18. Relationship between Rheological Behaviour and Final Structure of Al2O3 and YSZ Foams Produced by Replica

    Directory of Open Access Journals (Sweden)

    S. Y. Gómez

    2012-01-01

    Full Text Available Using rheological parameters of ceramic suspensions, it is possible to taylor the structure of the ceramic foams produced by replica. This method consists in the impregnation of a polymeric flexible template (polyurethane foam with a ceramic suspension (slurry containing the appropriate additives, followed by burning out organic compounds and additives and sintering the ceramic structure. In this work, ceramic foams were produced by the replica method from Al2O3 and 3% Y2O3-ZrO2. Rheological parameters of the ceramic suspensions were investigated to improve the mechanical performance of final structures. Different types and quantities of raw materials were combined in order to select the formulations for ceramic foams. The parameters that have a significant influence on the process are the binder type and the amount of solids. Significant changes on the hysteresis area of the suspensions resulted in a lower density of macrodefects in the material. Likewise, when the shear rate viscosity is enhanced, the thickness of the struts increased proportionally. Lastly, when the hysteresis area magnitude and the ceramic thickness increased, the material with higher uniformity was internally densified, and the stress concentration of the internal defects was smoothed

  19. Niveles de plomo en la población de alto riesgo y su entorno en San Ignacio, Fresnillo, Zacatecas, México Lead levels in high-risk populations and the surrounding environment in San Ignacio, Fresnillo, Zacatecas, México

    Directory of Open Access Journals (Sweden)

    Eduardo Manzanares-Acuña

    2006-06-01

    Full Text Available OBJETIVO: Determinar la concentración de plomo en la sangre de niños y mujeres, en periodo de lactancia o embarazadas, de la comunidad de San Ignacio, Fresnillo, en Zacatecas, así como en matrices de suelo, plantas, ceniza y barro vidriado, para determinar la exposición que genera una empresa recicladora de metales. MATERIAL Y MÉTODOS: El estudio se realizó de diciembre de 2004 al mes de abril de 2005. El Pb en sangre se midió por voltamperometría de redisolución anódica, mientras que se utilizó energía dispersa de fluorescencia por rayos X para las otras matrices. RESULTADOS: Con base en los criterios de la Norma Oficial Mexicana (NOM se encontró que 90% de los menores está en la categoría I, 5% se encuentra en la categoría II y el otro 5% se ubica en la categoría III. El suelo de los terrenos aledaños a la recicladora tiene en promedio 4 940 µg/g, en un intervalo de 73 a 84 238 µg/g. Las mayores concentraciones se localizan en los puntos más cercanos a la empresa. El suelo de San Ignacio tiene en promedio 109 µg/g. Se encontraron valores altos en el barro vidriado y la concentración del Pb en las plantas es superior a los 300 µg/g. CONCLUSIONES: A pesar de que la mayoría de los niños analizados presenta niveles de plomo en sangre que la Norma Mexicana señala como aceptables, varios estudios indican que existen efectos nocivos aun a concentraciones bajas. Los terrenos aledaños a la empresa están contaminados, y en esa medida los alimentos que ahí se producen, al ser consumidos, son una fuente de contaminación, que se agudiza con el uso de barro vidriado.OBJECTIVE:To determine the lead concentration in the blood of children and nursing or pregnant women from San Ignacio, Fresnillo, in Zacatecas, Mexico as well as in soil, plants, ash and lead-glazed pottery, in order to determine exposure due to a metal-recycling facility. MATERIAL AND METHODS: The study was carried out from December 2004 to April 2005. Lead in

  20. DETERMINACIÓN DE LA ENTALPIA DE INMERSIÓN Y CAPACIDAD DE ADSORCION DE UN CARBON ACTIVADO EN SOLUCIONES ACUOSAS DE PLOMO

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo

    2008-03-01

    Full Text Available Para un carbón activado comercial se determinan las cantidades de sitios ácidos y básicos totales con valores de 0,45 y 0,55 meqg-1 respectivamente, la entalpía de inmersión en solución 0,1 M de NaOH con un valor de –15,26 Jg-1, la entalpía de inmersión en solución 0,1 M de HCl  con un resultado de –36,63 Jg-1 y el punto de carga cero, PCZ, para un pH de 8,9.  De estos resultados se establece el carácter básico del sólido. Se determina la isoterma de adsorción a 298 K, del carbón activado en soluciones de Pb2+, y se obtiene una capacidad de adsorción de alrededor de 40 mg g-1, para la máxima adsorción. Se determina las entalpías de inmersión del carbón activado en soluciones acuosas de Pb2+, de diferente concentración, en un rango de 10 a 120 mg L-1 y se obtiene valores para la entalpías de inmersión en un rango de 5,12 a 48,7 Jg-1. Se estudia la superficie del carbón activado por microscopía electrónica de barrido antes y después de la adsorción del plomo, lo que permite observar la colocación del metal sobre el sólido.  

  1. Determination of the load state of lead-acid batteries using neural networks; Determinacion del estado de carga de baterias plomo-acido utilizando redes neuronales

    Energy Technology Data Exchange (ETDEWEB)

    Cristin V, Miguel A; Ortega S, Cesar A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    The charge of lead-acid batteries (LAB), as in any other type of batteries, consists of replacing the energy consumed during the discharge. Nevertheless, as no physical or chemical process is good enough to totality recharge a battery, it is necessary to supply to it more than the 100% of the energy demanded during its discharge. A critical factor to make a suitable load control of the batteries is to determine its own state of load. That is to say, to have an efficient load control, it is necessary to count on means that allow to accurately determining the residual capacity of the battery to deliver load. This one is the one of the aspects of greater interest in the research centers around world. For this reason, in this work it was pretended to develop a calculation algorithm of the state of load of batteries based on a fuzzy-neural network that could calculate the state of load without using the battery current as an input. This is because one of the main problems for the designers of battery load controllers is the correct supervision of the current that circulates around the system in all the rank of operation of the same one because the sensors do not have a linear behavior. [Spanish] La recarga de baterias plomo-acido (BPA), como cualquier otro tipo de baterias, consiste en reponer la energia consumida durante la descarga. Sin embargo, como ningun proceso fisico o quimico es lo bastante eficiente para recargar a totalidad una bateria, es necesario suministrarle mas del 100% de la energia demandada durante su descarga. Un factor critico para realizar un adecuado control de carga de las baterias, es determinar su propio estado de carga. Es decir, para tener un control de carga eficiente, es necesario contar con un medio que permita determinar con precision la capacidad remanente de la bateria para entregar carga. Este es uno de los aspectos de mayor interes en los centros de investigacion alrededor el mundo. Por tal razon, en este trabajo se propuso

  2. Tendencia de los niveles de plomo en la atmósfera de la zona metropolitana de la Ciudad de México: 1988-1998 Trends in atmospheric concentrations of lead in the Metropolitan Area of Mexico City: 1988-1998

    Directory of Open Access Journals (Sweden)

    Marlene Cortez-Lugo

    2003-01-01

    Full Text Available OBJETIVO: Describir las tendencias del plomo atmosférico asociadas a la eliminación paulatina del plomo de la gasolina y el uso de convertidores catalíticos en el auto transporte de la Ciudad de México, de 1988 a 1998. MATERIAL Y MÉTODOS: Estudio de series de tiempo que incluye las mediciones atmosféricas de plomo que se obtuvieron, entre 1988 y 1998, de nueve estaciones de la red manual de monitoreo atmosférico de la Ciudad de México. Las intervenciones evaluadas fueron la introducción de gasolina Magnasin, el uso de convertidores catalíticos y el descenso en la concentración de plomo hasta su eliminación total de la gasolina utilizada en los auto transportes. Se describen las tendencias de plomo por monitor, por zona geográfica, utilizando un modelo de regresión que incorpora una estructura de auto-correlación. RESULTADOS: La introducción de gasolina sin plomo y de los convertidores catalíticos se asoció con un descenso en la concentración de plomo atmosférico en 23%, la reducción paulatina del plomo en la gasolina ocasionó una reducción acumulada de 89% en todas las zonas estudiadas. CONCLUSIONES: La introducción de la gasolina sin plomo ha logrado abatir las concentraciones ambientales de este contaminante de una manera importante.OBJECTIVE: To describe the trends in airborne lead levels and their association with the control measures implemented from 1988 to 1998 to phase out lead from gasoline that included the introduction of a lead-free gasoline and the use of catalytic converters in automobiles in Mexico City. MATERIAL AND METHODS: Data of atmospheric lead levels were obtained from the 9 field stations included in the local air quality monitoring network (RMMA. Trends for airborne lead are shown by monitor, monitoring area and for the entire metropolitan zone. Analysis of data was performed using linear regression models including autocorrelation analysis. The models were validated by standard diagnostic

  3. River fishing as an economic resource in Late Iberian times: an example from the site of Los Castellones de Céal (Hinojares, Jaén

    Directory of Open Access Journals (Sweden)

    Mayoral Herrera, Victorino

    2000-06-01

    Full Text Available This paper describes the finding of a group of folded lead sheets in the Ibero-roman level at Castellones de Céal. As they have been traditionally used as weights for fishing nets, the practice at the site of river fishing as an economic resource is inferred. Some other archaeological examples of this activity are also examined.

    En este trabajo se describen una serie de láminas enrolladas de plomo aparecidas en el nivel iberorromano de Castellones de Céal y que habitualmente son empleadas como lastres en redes de pesca. Se deduce de ello el empleo de la pesca fluvial como recurso económico, revisándose los ejemplos conocidos de esta actividad en el registro arqueológico.

  4. Nonlinear relationship between the Product Consistency Test (PCT) response and the Al/B ratio in a soda-lime aluminoborosilicate glass

    Science.gov (United States)

    Farooqi, Rahmat Ullah; Hrma, Pavel

    2016-06-01

    We have investigated the effect of Al/B ratio on the Product Consistency Test (PCT) response. In an aluminoborosilicate soda-lime glass based on a modified International Simple Glass, ISG-3, the Al/B ratio varied from 0 to 0.55 (in mole fractions). In agreement with various models of the PCT response as a function of glass composition, we observed a monotonic increase of B and Na releases with decreasing Al/B mole ratio, but only when the ratio was higher than 0.05. Below this value (Al/B < 0.05), we observed a sharp decrease that we attribute to B in tetrahedral coordination.

  5. The relationship between the reliability of transistors with 2D AlGaN/GaN channel and organization type of nanomaterial

    Science.gov (United States)

    Emtsev, V. V.; Zavarin, E. E.; Oganesyan, G. A.; Petrov, V. N.; Sakharov, A. V.; Shmidt, N. M.; V'yuginov, V. N.; Zybin, A. A.; Parnes, Ya. M.; Vidyakin, S. I.; Gudkov, A. G.; Chernyakov, A. E.

    2016-07-01

    The first experimental results demonstrating that the carrier mobility in the AlGaN/GaN 2D channel of transistor structures (AlGaN/GaN-HEMT) is correlated with the manner in which the nanomaterial is organized and also with the operation reliability of transistor parameters are presented. It is shown that improving the nature of organization of the nanomaterials in AlGaN/GaN-HEMT structures, evaluated by the multifractal parameter characterizing the extent to which a nanomaterial is disordered (local symmetry breaking) is accompanied by a significant, several-fold increase in the electron mobility in the 2D channel and in the reliability of parameters of transistors fabricated from these structures.

  6. Synchrotron-based XPS studies of AlGaN and GaN surface chemistry and its relationship to ion sensor behaviour

    International Nuclear Information System (INIS)

    Highlights: • Soft X-ray was used to study the surface chemistry of GaN and AlGaN. • The surface chemistry and sensor behaviour were investigated. • The oxide of aluminum is significantly more reactive than gallium. • The Cl− ions are greater in GaN samples compared to AlGaN samples. - Abstract: Soft X-ray photoelectron spectroscopy was used to investigate the fundamental surface chemistry of both AlGaN and GaN surfaces in the context of understanding the behaviour of AlGaN/GaN heterostructures as chemical field-effect transistor (CHEMFET) ion sensors. AlGaN and GaN samples were subjected to different methods of oxide growth (native oxide and thermally grown oxide) and chemical treatment conditions. Our investigations indicate that the etching of the oxide layer is more pronounced with AlGaN compared to GaN. Also, we observed that chloride ions have a greater tendency to attach to the GaN surface relative to the AlGaN surface. Furthermore, chloride ions are comparatively more prevalent on surfaces treated with 5% HCl acid solution. The concentration of chloride ions is even higher on the HCl treated native oxide surface resulting in a very clear deconvolution of the Cl 2p1/2 and Cl 2p3/2 peaks. For GaN and AlGaN surfaces, a linear response (e.g. source-drain current) is typically seen with variation in pH of buffered solutions with constant reference electrode voltage at the surface gate; however, an inverted bath-tub type response (e.g. a maximum at neutral pH and lower values at pH values away from neutral) and a general tendency to negative charge selectivity has been also widely reported. We have shown that our XPS investigations are consistent with the different sensor response reported in the literature for these CHEMFET devices and may help to explain the differing response of these materials

  7. Synchrotron-based XPS studies of AlGaN and GaN surface chemistry and its relationship to ion sensor behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Khir, Farah Liyana Muhammad, E-mail: 21001899@student.uwa.edu.au [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); Myers, Matthew, E-mail: Matt.Myers@csiro.au [School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); CSIRO Earth Science and Resource Engineering, Kensington, Western Australia 6151 (Australia); Podolska, Anna [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); Department of Exploration Geophysics, Curtin University of Technology, 26 Dick Perry Avenue, ARRC, Kensington, Western Australia 6151 (Australia); Sanders, Tarun Maruthi [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); Baker, Murray V., E-mail: murray.baker@uwa.edu.au [School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); Nener, Brett D., E-mail: brett.nener@uwa.edu.au [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia); Parish, Giacinta, E-mail: giacinta.parish@uwa.edu.au [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Crawley, Western Australia 6009 (Australia)

    2014-09-30

    Highlights: • Soft X-ray was used to study the surface chemistry of GaN and AlGaN. • The surface chemistry and sensor behaviour were investigated. • The oxide of aluminum is significantly more reactive than gallium. • The Cl{sup −} ions are greater in GaN samples compared to AlGaN samples. - Abstract: Soft X-ray photoelectron spectroscopy was used to investigate the fundamental surface chemistry of both AlGaN and GaN surfaces in the context of understanding the behaviour of AlGaN/GaN heterostructures as chemical field-effect transistor (CHEMFET) ion sensors. AlGaN and GaN samples were subjected to different methods of oxide growth (native oxide and thermally grown oxide) and chemical treatment conditions. Our investigations indicate that the etching of the oxide layer is more pronounced with AlGaN compared to GaN. Also, we observed that chloride ions have a greater tendency to attach to the GaN surface relative to the AlGaN surface. Furthermore, chloride ions are comparatively more prevalent on surfaces treated with 5% HCl acid solution. The concentration of chloride ions is even higher on the HCl treated native oxide surface resulting in a very clear deconvolution of the Cl 2p{sub 1/2} and Cl 2p{sub 3/2} peaks. For GaN and AlGaN surfaces, a linear response (e.g. source-drain current) is typically seen with variation in pH of buffered solutions with constant reference electrode voltage at the surface gate; however, an inverted bath-tub type response (e.g. a maximum at neutral pH and lower values at pH values away from neutral) and a general tendency to negative charge selectivity has been also widely reported. We have shown that our XPS investigations are consistent with the different sensor response reported in the literature for these CHEMFET devices and may help to explain the differing response of these materials.

  8. Commentary: Disregard for Others: Empathic Dysfunction or Emotional Volatility? The Relationship with Future Antisocial Behavior--Reflections on Rhee et al. (2013)

    Science.gov (United States)

    Blair, R. J. R.

    2013-01-01

    There have long been suggestions that reduced levels of empathy are associated with an increased risk for antisocial behavior (e.g., Miller & Eisenberg, 1988). The article by Rhee and colleagues on typically developing children (Rhee et al., 2012) is important because it is one of the few studies to longitudinally examine the relationship…

  9. Visualizing MOF Mixed Matrix Membranes at the Nanoscale: Towards Structure-Performance Relationships in CO 2 /CH 4 Separation Over NH 2 -MIL-53(Al)@PI

    NARCIS (Netherlands)

    Rodenas, T.; Van Dalen, M.; Garcia-Perez, E.; Serra-Crespo, P.; Zornoza, B.; Kapteijn, F.; Gascon, J.

    2013-01-01

    Mixed matrix membranes (MMMs) composed of metal organic framework (MOF) fi llers embedded in a polymeric matrix represent a promising alternative for CO 2 removal from natural gas and biogas. Here, MMMs based on NH 2 -MIL-53(Al) MOF and polyimide are successfully synthesized with MOF loadings up to

  10. Relationship between transport properties and band diagrams in InAsxSb1−x/Al0.1In0.9Sb quantum wells

    International Nuclear Information System (INIS)

    The resistivity of InAs0.1Sb0.9/Al0.1In0.9Sb quantum wells (QWs) is much lower than that of InSb/Al0.1In0.9Sb QWs, staying low resistivity even at low temperature. Fundamental difference in low temperature transport properties between InSb/Al0.1In0.9Sb and InAs0.1Sb0.9/Al0.1In0.9Sb QWs was revealed, based on the band diagram calculations of these QWs. Band diagrams of InAsxSb1−x/Al0.1In0.9Sb QWs showed that the energy band of the InAsxSb1−x layer moves downward with increasing As content x. The QW is type I at x equal to 0, becomes type II at x equal to 0.1. The Fermi level (EF) of the InSb QWs lies in the band gap and below apart from the bottom of the conduction band, while EF of the InAs0.1Sb0.9 QWs is above the bottom of the conduction band of the well. The calculated sheet carrier densities are in good agreement with the experimental results. It well explains that the sheet carrier density difference between InSb and InAs0.1Sb0.9 QWs mainly originates from this band diagram difference and the position of EF

  11. AN INVESTIGATION OF RELATIONSHIP BETWEEN PHASE SEPARATION AND CRYSTALLIZATION OF ZnO-Al2O3-SiO2 GLASSES

    OpenAIRE

    Jiazhi, Li; Ying, Shan; Guanging, Hu

    1982-01-01

    TEM, DTA, X-ray diffraction results reveal that there is a strong tendency to phase separation into two immiscible liquid phases in the ZnO-Al2O3- SiO2 (ZAS) glasses. β-quartz solid solution would precipitate as metastable initial crystalline phase, when the degree of phase separation of the original glass is low, whereas β-quartz solid solution and β-Willemite solid solution would both be precipitate when the degree of phase separation is more complete. It was found that degree of phase sepa...

  12. The Relationship between Self-esteem and Quality of Life of Patients with Idiopathic Thrombocytopenic Purpura at Isfahan's Sayed Al-Shohada Hospital, Iran, in 2013

    OpenAIRE

    Hemati, Zeinab; Kiani, Davood

    2016-01-01

    Background: Idiopathic thrombocytopenic purpura (ITP) is a chronic disease which is accompanied with hopelessness and loss of the sense of well-being due to its symptoms and treatment. It also affects patients' sense of social and spiritual well-being. This disorder decreases patients' self-esteem and their quality of life by changing their mental image and self-confidence. This study was performed to find the relationship between self-esteem and quality of life of patients with ITP. Subjects...

  13. Prevalence of intestinal parasitic infections and its relationship with socio-demographics and hygienic habits among male primary schoolchildren inAl-Ahsa,SaudiArabia

    Institute of Scientific and Technical Information of China (English)

    Hamdan Ibrahim Al-Mohammed; Tarek Tawfik Amin; Elsayed Aboulmagd; Hatem Refaat Hablus; Burhan Omar Zaza

    2010-01-01

    Objective:To investigate the prevalence of different intestinal parasitic infections among male primary schoolchildren in Al-Ahsa, Saudi Arabia, and to explore the possible relative socio-economic, environmental and behavioural sanitary correlates.Methods: A cross-sectional descriptive study was performed. A total of1 289 male students aged from7to12years were selected randomly from20urban and12rural primary schools by multistage sampling method. Data collection was carried out by self administered questionnaire form to the parents/guardians of students and included inquires about socio-demographics, environmental conditions, and behavioural sanitary habits. Stool analysis was carried out to examine the presence of intestinal parasitic infections.Results:Overall prevalence of parasitic infections was27.2%, more among rural students. Frequently encountered infections included Entamoeba histolytica/dispar(8.2%), Giardia lamblia(6.5%),Entamoeba coli(4.0%)andEnterobius vermicularis(1.6%). Logistic regression revealed that lower maternal educational level and occupational status, low family income, big family size, poor personal hygienic practices and positive history of previous intestinal infections among family members increased the likelihood of infections.Conclusions:Although of low magnitude, intestinal parasitic infections still represent a public health concern among male schoolchildren in Al-Ahsa region. Socio-demographic and poor personal hygienic habits are the main predictors for these infections.

  14. Solidificación-Estabilización de Cromo, Níquel y Plomo en una Matriz Sólida de Hormigón Fabricada con Cemento Portland Solidification-Stabilization of Chromium, Nickel and Lead in a Concrete Solid Matrix of Portland Cement

    Directory of Open Access Journals (Sweden)

    René A Lara-Díaz

    2009-01-01

    Full Text Available Se validó la técnica de cementación como alternativa para la solidificación-estabilización de residuos sintéticos de metales pesados, cromo, níquel y plomo, usando probetas sólidas de hormigón de cemento Portland. El proceso de cementación se realiza a partir de una mezcla base para obtener hormigón con resistencia a la compresión de 29.4 N/mm², los metales fueron incorporados como sales metálicas en el agua de amasado. Se realizaron pruebas de resistencia a la compresión, lixiviación de metales por la prueba PECT con absorción atómica y se calculó la eficiencia de retención. El hormigón fabricado con cemento Portland es adecuado para su uso en la solidificación-estabilización de níquel y plomo a una concentración máxima de 0.43% para níquel y 1.94% para plomo.The technique of cementation was validated as an alternative method for the solidification-stabilization of heavy metal synthetic wastes, chromium, nickel and lead, using concrete solid cylinders made of Portland cement. The cementation process takes place starting with a concrete mixture base with compressive strength of 29.4 N/mm². Metals were incorporated as metallic salts in the mixing water. Tests of compressive strength, leaching of metals by PECT with atomic absorption were performed and retention efficiencies were calculated. Concrete made with Portland cement is appropriate for the solidification-stabilization of nickel and lead, with maximum concentrations of 0.43% of nickel and 1.94% of lead in concrete.

  15. ALS - resources

    Science.gov (United States)

    Resources - ALS ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (ALS) Registry -- ...

  16. 埃及塞西政权与俄罗斯的关系%Relationship between Egypt under Al-Sisi Regime and Russiaa

    Institute of Scientific and Technical Information of China (English)

    赵军

    2016-01-01

    塞西主政埃及后,埃及与俄罗斯关系出现跨越式发展,双方在政治、经济、军事、能源等诸多领域进行了合作。埃俄两国在困境之中的互相支持、战略上相互需求、领导人偏好以及历史记忆等构成埃俄关系迅速升温的主要因素。埃俄关系变化对两国自身和欧美中东政策产生一定影响。未来埃俄关系能否持续有效地向前发展将取决于埃俄互信的构建程度、两国在中东热点问题上能否消除分歧以及欧美对俄政策变化程度等三个方面。%After Egypt is governed by Sisi, great-leap-forward development appears in the relationship between Egypt and Russia and they have had cooperation in political, economic, military, energy and many other fields. The mutual support of Egypt and Russia in plight, their mutual needs in strategy, the preferences and historical memories of their leaders, etc. constitute the major factors promoting the rapid elevation of Egypt-Russia relationship. The changes in Egypt-Russia relationship will have certain influence on the two countries and the Middle East policies of Europe and America. Whether the Egypt-Russia relationship will develop forward continuously and effectively will be determined by three aspects including the construction of mutual trust between Egypt and Russia, the settlement of differences between the two countries in hot issues of Middle East, and the change degree of European and American policies to Russia.

  17. Interacción de Anhidrita con Soluciones Acuosas que Contienen Plomo. I. Evolución Fisicoquímica del Sistema

    OpenAIRE

    Morales Sánchez-Migallón, Juan; Astilleros, José Manuel; Jiménez, Amalia; Fernández Díaz, Lurdes

    2011-01-01

    El Pb es un metal tóxico cuyo uso extensivo durante siglos ha derivado en la liberación de este elemento al medio ambiente, resultando potencialmente peligroso para la salud pública. La exposición de los organismos a este elemento puede causar graves problemas para la salud, afectando a múltiples sistemas del organismo, como el sistema nervioso, sanguíneo, digestivo, cardiovascular o el sistema renal. Afecta particularmente al sistema nervioso de niños, inc...

  18. La composición isotópica del azufre y del plomo en las mineralizaciones de Zn-Pb del Valle de Arán (Pirineo central y su significado metalogenético

    Directory of Open Access Journals (Sweden)

    Pujals, I.

    1996-12-01

    Hercínico no ha afectado significativamente las composiciones isotópicas originales de los sulfuros y las variaciones de la δ34S de los mismos en cada una de las dos litologías encajantes, podrían explicarse por pequeños cambios en la fO2, temperatura o pH durante la formación de los depósitos. La composición isotópica del plomo de 6 galenas analizadas presenta las relaciones siguientes: 18,02≤ 206Pb/204Pb≤ 18,08; 15,66≤ 207Pb204Pb≤ 15,70 y 38,16 ≤ 208Pb/ 204Pb≤ 38,29, similares a los reportados por Marcoux (1987 en los depósitos de Pierrefitte (Pirineo Central, Francia. A diferencia de los datos de isótopos de azufre, estos valores son muy homogéneos y apuntan hacia un reservorio de plomo situado en la corteza superior. Las edades calculadas a partir del modelo de evolución del plomo de Cumming y Richards (1975, varían entre 422 y 452 m.a. (Ordovícico superior, edad de los materiales encajantes. Este dato confirma la hipótesis del origen sedimentario-exhalativo de las mineralizaciones.

  19. La relación lenguaje y conocimiento y su aplicación al aprendizaje escolar The relationship between language and knowledge and its application to school learning

    Directory of Open Access Journals (Sweden)

    Ángela Camargo Uribe

    2010-06-01

    Full Text Available Este artículo expone tres aproximaciones teóricas que han sido propuestas para la comprensión de la relación entre el lenguaje y conocimiento: la del cognitivismo, la del socio constructivismo y la del socio constructivismo discursivo. Posteriormente, presenta secuencias de aula que ilustran cada uno de estos enfoques, a fin de analizar y evaluar cada postura desde el punto de vista del aprendizaje escolar. Finalmente, llega a conclusiones sobre las relaciones entre los tres enfoques considerados respecto de su aplicación específica al contexto pedagógico y didácticoThis paper explains three theoretical approaches that have been proposed to explain the relationship between language and knowledge: cognitivism, social constructivism and discursive constructivism. Later on, the paper presents different classroom dialogues and speech sequences that illustrate each approach to analyze and evaluate them from the point of view of school learning. Finally, some statements are about the relationships among the three approaches and with respect to their application to the classroom context

  20. Structure-property relationships of mullite-SiC-Al{sub 2}O{sub 3}–ZrO{sub 2} composites developed during carbothermal reduction of aluminosilicate minerals

    Energy Technology Data Exchange (ETDEWEB)

    Seifollahzadeh, P., E-mail: Pseifollahzadeh.mat@stu.yazd.ac.ir; Kalantar, M.; Ghasemi, S.S.

    2015-10-25

    Evolution of SiC and ZrO{sub 2} in the matrix of Al{sub 2}O{sub 3} or mullite have been reported to enhance a higher toughness, good thermal shock resistance (lowering thermal expansion and improving thermal conductivity) and improved creep resistance of composite materials. In this study, the structure-property relationships of mullite-Al{sub 2}O{sub 3} matrix composites have been investigated in conjunction with the evolution of reinforcing phases such as SiC–ZrO{sub 2} by an economical heat treatment process called carbothermal reduction of inorganic minerals (Kaolinite, Andalusite, Zircon). The influence of starting materials in relation with the variation in molar ratio of C/SiO{sub 2} on the phase composition, microstructures, physical and mechanical properties have been studied. Light microscopy has been supplemented with scanning electron microscopy, XRD analysis, differential thermal and thermal gravity analysis to follow the structure-property relationships. The experimental results show that with increasing of C/SiO{sub 2} ratio in starting materials, very fine SiC whiskers have been formed in the microstructures. Moreover, the densification and strength are considerable higher for ZrO{sub 2} + SiC containing composites in comparison to that of only SiC added ones. Furthermore, it has been found that the appropriate ratio of C/SiO{sub 2} with the associated firing temperature to develop a higher densification and SiC crystallization have been related to the 3.5, 1550 °C for kaolinite, 3.5, 1450 °C for zircon and 5.5, 1600 °C for andalusite containing composite samples, respectively. - Highlights: • In-situ formation of SiC whiskers in matrix of alumina + mullite composites. • Advantage of availability, abundance and economical for starting materials. • Lack of environmental problems in comparable of utilization of whiskers directly. • A mixture of coke and alumina as a protective layer instead of inert atmosphere. • Fabrication of advanced

  1. Correlación de protoporfirina zinc y plomo en sangre en trabajadores de fábricas de baterías, de Bogotá, Colombia Correlation of zinc protoporphyrin with blood lead levels in car battery industry workers in Bogota, Colombia

    Directory of Open Access Journals (Sweden)

    Omayda Cárdenas-Bustamante

    2001-06-01

    Full Text Available Objetivo. Determinar la utilidad de la protoporfirina zinc en sangre (PPz como indicador de exposición a plomo en trabajadores de fábricas de baterías. Material y métodos. Se hizo un estudio transversal en 116 trabajadores de fábricas de baterías del sector informal en Bogotá, Colombia. La información sobre variables generales, ocupacionales y de salud fue obtenida por medio de una entrevista con los trabajadores. Se establecieron dos categorías para los valores de PPz: aquellos por debajo del valor límite de (70 µg/dl, y aquellos por arriba de este valor. Se empleó análisis de regresión lineal para medir la correlación entre los valores logarítmicos de PPz (>70 µg/dl y plomo en sangre (PbS (>38 µg/dl. Resultados. Se encontró un coeficiente de correlación semilogarítmica r=0.54, además de posibles asociaciones estadísticamente significativas entre los niveles elevados de PPz y el oficio actual de exposición directa (RM:3.35, IC 95% 1.02-11.91; p:0.02, emplear plomo como materia prima (RM:7.80, IC 95% 2.96-21.03; phttp://www.insp.mx/salud/index.htmlObjective. To determine the usefulness of zinc protoporphyrin in blood (PPz as an indicator of lead exposure in workers of the homemade car battery industry. Material and methods. A cross-sectional study was performed in 116 workers of the car battery industry in Bogotá, Colombia. Data on general, occupational, and health variables were collected by interview. Two categories of PPz values were established: Those below the cutoff value (70 µg/dL and those above it. A linear regression analysis was performed to measure the correlation between logarithm values of PPz (>70 µg/dL and lead in blood (PbB (>38 µg/dL. Results. A semi-logarithmic correlation coefficient of r=0.54 was found, and statistically significant associations between high levels of PPz and direct exposure to lead were observed (OR:3.35, 95% IC 1.02-11.91; p:0.02; for workers who often use lead as a raw material

  2. Relationship between Ca{sup 2+} concentration and the properties of codoped Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12}:Ce scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Fang [Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States); Koschan, Merry [Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States); Wu, Yuntao; Melcher, Charles L. [Materials Science and Engineering, University of Tennessee, Knoxville, TN (United States); Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States)

    2015-10-11

    Codoping is a method of current interest for modifying the properties of scintillators. The study reported here explores the effect of codoping on cerium doped Gd{sub 3}Ga{sub 3}Al{sub 2}O{sub 12} (GGAG:Ce) crystals with various concentrations of Ca. These single crystals were grown via the Czochralski technique with Ce concentrations fixed at 0.2 at% and Ca concentrations ranging from 0.1 at% to 0.4 at% in the initial melt. The relationship between dopant concentration and light yield, rise time, and scintillation and photoluminescence decay times was determined. In addition, the absorbance, photoluminescence, radioluminescence, afterglow and thermoluminescence dependence on the dopant concentration are presented. In some of the Ca codoped crystals, an additional luminescence center was observed with an excitation wavelength of 350 nm and an emission wavelength of 400 nm and a photoluminescence decay time of ~3.5 ns. - Highlights: • GGAG:Ce crystals codoped with various Ca concentrations were grown by a CZ method. • The scintillation decay times and afterglow were improved by Ca codoping. • Ca codoping promotes valence state transition from Ce{sup 3+} to Ce{sup 4+} in GGAG. • GGAG:Ce with 0.4% Ca shows the shortest decay time (~27 ns)

  3. Evaluación de la incertidumbre en la determinación de plomo en sangre por voltamperometría de redisolución anódica, aplicando el modelo de calibración ponderado de adición patrón generado por simulación de monte Carlo

    OpenAIRE

    Delgado, Gustavo; Vanegas, Manuel; Salazar, Jairo

    2013-01-01

    El presente trabajo pretende demostrar que la evaluación de la incertidumbre en la determinación de plomo en sangre por voltamperometría de redisolución anódica, aplicando el análisis de regresión lineal ponderado por adición patrón y generado por simulación de Monte Carlo, tiene mayor congruencia con los resultados experimentales que con los obtenidos por la aplicación del enfoque clásico basado en la ley de la propagación de la incertidumbre. Para el primer caso, se elaboró el programa en M...

  4. AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Desport Estelle

    2012-08-01

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

  5. Relación entre adherencia objetiva al tratamiento en la diabetes infantil y variables psicológicas de los cuidadores Relationship between objective treatment compliance in infantile diabetes and psychological variables of caregivers

    Directory of Open Access Journals (Sweden)

    Consuelo Arenas Bermúdez

    2007-11-01

    Full Text Available Justificación: La diabetes es una elevación crónica de glucosa en sangre. En niños, el tratamiento no es administrado por el paciente sino por su cuidador. Así, las características personales que aseguren la adherencia al tratamiento dependen de otra persona. Objetivo Principal: Identificar qué características personales y ambientales del cuidador favorecen o interfieren la adherencia al tratamiento. Diseño y Metodología: Participaron 60 cuidadores principales de niños diabéticos (edad: 1-15 años. Evaluándose optimismo, autoeficacia, neuroticismo, estrategias de afrontamiento, estilos educativos, apoyo social (del cuidador, así como adherencia objetiva en los niños (análisis sanguíneo, además de variables demográficas y familiares de ambos. Se realizaron correlaciones y diferencias entre grupos utilizando variables de agrupamiento como tener o no adherencia al tratamiento, entre otras. El estudio duró un año durante el cual los cuidadores asistieron a sesiones psicoeducativas sobre la enfermedad. Resultados: Principales y Conclusiones. El perfil del cuidador con mejor adherencia objetiva: alguien con buenos conocimientos sobre la enfermedad, temor ante las consecuencias de no seguir el tratamiento, acostumbrado a afrontar problemas buscando soluciones, con una actitud y motivación positivas y sin sentirse culpable. En su relación con los pacientes muestra un alto grado de control y de afecto (cuidador democrático.Justification: Diabetes is a chronic elevation of glucose in the blood. In the case of children, treatment is not administrated by the patient but their caregivers. In this sense, personal characteristics that increase treatment compliance are not dependent on oneself but on other people. Main Aim: To find personal and environmental characteristics that may increase or decrease objective treatment compliance. Design and Method: Participants in this study were 60 principal caregivers of diabetic children (aged: 1

  6. Revisión de la relación existente entre la exposición ocupacional al formaldehído y leucemia Review relationship between occupational exposure to formaldehyde and leukemia

    Directory of Open Access Journals (Sweden)

    Katerine Greace Ajalla Puente

    2013-03-01

    Full Text Available Introducción: El formaldehído es un cancerígeno conocido, su relación con un aumento del riesgo de leucemia en exposición ocupacional continua en debate a pesar de los diversos estudios realizados. Presentamos una revisión bibliográfica cuyo objetivo es conocer el nivel de evidencia existente entre la posible relación causal de la exposición laboral al formaldehído y la aparición de leucemia, mediante el análisis sistemático de la producción científica publicada entre los años 2008 y 2012. Metodología: Se realizó una búsqueda bibliográfica en las bases de datos Medline, IBECS, LILACS, CROCHRANE, OSH UPDATE, CISDOC, WEB OF KNOWLEDGE y SCOPUS, utilizando una estrategia de búsqueda a partir de términos "MeSH". Se obtuvieron un total 302 artículos de los que finalmente se seleccionaron 7 que cumplían los requisitos establecidos. De ellos, 4 eran metaanálisis, 2 estudios de casos y controles, 1 estudio de cohortes. Para la asignación del nivel de evidencia se utilizaron los criterios de la Scottish Intercollegiate Guidelines Network (SIGN. Resultados: Se han encontrado riesgos elevados para los niveles de máxima exposición y también datos de mortalidad estadísticamente significativa para leucemia mieloide con aumento del número de años de prácticas de embalsamamiento. Tres metaanálisis aportan RR altos para leucemia mieloide. Un cuarto metaanálisis al excluir los estudios de mortalidad proporcional obtiene que los resultados basados en cohortes y estudios caso-control no sugieren una asociación entre exposición al formaldehído y leucemia. Discusión: Los estudios disponibles presentan limitaciones que no hacen posible establecer niveles de evidencia suficientes que confirmen la relación concluyente entre exposición a formaldehído y aparición de leucemias en trabajadores. Nuestra revisión bibliográfica contiene estudios heterogéneos en diferentes poblaciones donde hemos encontrado valores de asociación (RR

  7. Correlação entre permeabilidade e resistência mecânica de filtros cerâmicos no sistema Al2O3-SiC Relationship between permeability and mechanical strength of Al2O3-SiC ceramic filters

    Directory of Open Access Journals (Sweden)

    V. R. Salvini

    2000-06-01

    Full Text Available Tem sido crescente o uso de cerâmicas reticulares em processos de refino e purificação de metais fundidos, filtração de gases quentes e combustão catalítica. A aplicação depende da composição química e das propriedades físicas do material (número de poros por polegada linear (ppi, porosidade e diâmetro de poro. Há um consenso de que a melhoria das propriedades dos filamentos resulta em um melhor desempenho mecânico do filtro cerâmico. Entretanto, a análise dos valores de resistência mecânica não pode ser considerada isoladamente, uma vez que para filtros cerâmicos esta tem que estar associada à permeabilidade. Neste trabalho é feita uma análise entre as propriedades fluidodinâmicas e mecânicas de filtros cerâmicos no sistema Al2O3-SiC na faixa de 8 a 90 ppi. Os resultados obtidos permitem considerações tanto no aspecto do processamento cerâmico quanto no modelamento mecânico apresentado na literatura.Reticulate ceramics have been increasingly employed in purification of gases, liquid metals and in catalytic processes. The application area usually depends on the chemical composition and the physical properties (porosity, pore size and pore counting (ppi. In most cases, reticulate ceramics are submitted to compression loads at high temperatures, which makes the durability of these cellular materials be ultimately related to the mechanical quality of the struts. In filtration applications, it is also important the evaluation of fluid dynamic properties of the ceramic, specifically its permeability to fluid flow. In this work, a relationship between mechanical properties and permeability constants of Al2O3-SiC ceramic foam filters with 8 to 90 ppi is presented. Results were associated with the processing technique and with the mechanical modeling presented in the literature.

  8. New constraints on the relationship between 26Al and oxygen, calcium, and titanium isotopic variation in the early Solar System from a multielement isotopic study of spinel-hibonite inclusions

    Science.gov (United States)

    Kööp, Levke; Nakashima, Daisuke; Heck, Philipp R.; Kita, Noriko T.; Tenner, Travis J.; Krot, Alexander N.; Nagashima, Kazuhide; Park, Changkun; Davis, Andrew M.

    2016-07-01

    We report oxygen, calcium, titanium and 26Al-26Mg isotope systematics for spinel-hibonite inclusions (SHIBs), a class of calcium-aluminum-rich inclusions (CAI) common in CM chondrites. In contrast to previous studies, our analyses of 33 SHIBs and four SHIB-related objects obtained with high spatial resolution demonstrate that these CAIs have a uniform Δ17O value of approximately -23‰, similar to many other mineralogically pristine CAIs from unmetamorphosed chondrites (e.g., CR, CV, and Acfer 094). Five SHIBs studied for calcium and titanium isotopes have no resolvable anomalies beyond 3σ uncertainties. This suggests that nucleosynthetic anomalies in the refractory elements had been significantly diluted in the environment where SHIBs with uniform Δ17O formed. We established internal 26Al-26Mg isochrons for eight SHIBs and found that seven of these formed with uniformly high levels of 26Al (a multi-CAI mineral isochron yields an initial 26Al/27Al ratio of ∼4.8 × 10-5), but one SHIB has a smaller initial 26Al/27Al of ∼ 2.5 × 10-5, indicating variation in 26Al/27Al ratios when SHIBs formed. The uniform calcium, titanium and oxygen isotopic characteristics found in SHIBs with both high and low initial 26Al/27Al ratios allow for two interpretations. (1) If subcanonical initial 26Al/27Al ratios in SHIBs are due to early formation, as suggested by Liu et al. (2012), our data would indicate that the CAI formation region had achieved a high degree of isotopic homogeneity in oxygen and refractory elements before a homogeneous distribution of 26Al was achieved. (2) Alternatively, if subcanonical ratios were the result of 26Al-26Mg system resetting, the clustering of SHIBs at a Δ17O value of ∼-23‰ would imply that a 16O-rich gaseous reservoir existed in the nebula until at least ∼0.7 Ma after the formation of the majority of CAIs.

  9. Relationship between

    Institute of Scientific and Technical Information of China (English)

    TIAN; Lide

    2001-01-01

    [1]Craig, H., Isotopic variations in meteoric waters, Science, 1961,133: 17020703.[2]Dansgaard, W., Stable isotope in precipitation, Tellus, 1964, 14(4): 436-468.[3]Merlivat, L., Jouzel, J., Global climate interpretation of the deuterium-oxygen 18 relationship for precipitation, J. Geophys.Res.. 1979, 84: 5029-5033.[4]Jouzel, J., Merlivat, L., Deuterium and oxygen-18 in precipitation: modeling of the isotope effects during snow formation.J. Geophys. Res., 1984, 89(D7): 11749-11757.[5]Sonntag, C., Klitzsch, E., Lohnert, E. P. et al., Palaeoclimatic information from deuterium and oxygen-18 in Carbon- 14-dated North Saharan groundwaters, in Isotope Hydrology, IAEA,Vienna, 1979, 569-581.[6]Armengaud, A., Koster, R. D., Jouzel, J. et al., Deuterium excess in Greenland snow: analysis with simple and complex models, J. Geophys. Res., 1998, 103(D8): 8947-8953.[7]Jouzel, J., Merlivat, L., Lorius, C., Deuterium excess in an East Antarctic ice core suggests higher relative humidity at the oceanic surface during the last glacial maximum, Nature, 1982, 299 (5885): 688-691.[8]Qin Dahe, Ren Jiawen, Wang Wenti, et al., Distribution of δD in 25 cm surface snow across the Antarctic, Science in China, Ser. B, 1992,22(7): 768-776.[9]Yao Tandong, Ding Liangfu, Pu Jianchen et al., Characteristic of δ 18O in snow and its relation with moisture sources in Tanggula Mountains, Tibetan Plateau, Chinese Science Bulletin (in Chinese), 1991, (20): 1570-1573.[10]Zhang Xinping, Shi Yafeng, Yao Tandong, Variational features of precipitation, δ 18O in Northeast Qinghai-Tibet Plateau.Science in China, Ser. D, 1995, 38(7): 854-864.[11]Zhang Xinping, Yao Tandong, Relations between weather systems affecting Tibetan Plateau and oxygen isotope in precipitation, Journal of Glaciology and Geocryology (in Chinese), 1995, 17(2): 125-131.[12]Tian Lide, Yao Tandong, Yang Zhihong, δ18O in precipitation and moisture sources upon the Tibetan Plateau, Cryosphere

  10. Relationship between liquid structure and property Ⅱ——Kinematic viscosity of Mg-9Al melt and its relationship with the microstructure%液态结构与性质关系Ⅱ——Mg-9Al熔体的运动黏度及与熔体微观结构的关系

    Institute of Scientific and Technical Information of China (English)

    弭光宝; 李培杰; ОхапкиАВ; Kонстантиннова Н Ю; Сабирэянов А А; Попелъ П C

    2011-01-01

    basic unit of β phase-like residual bond structures causes an abnormal change of viscosity in the first heating process; in the subsequent cooling process and the second heating process, the melt reaches a new dynamic equilibrium state, and Al atoms are uniformly distributed in the melt.At this time, the size of Mg-Al average atomic cluster ds and the number of short-range order atoms Ns inside them increase (decrease) monotonically with temperature, and the relationship between viscosity v and size of average atomic clusters ds is expressed as a linear function, i.e., v = v0 + K · ds, which presents a new way for revealing micro-structure change of alloy melt and further understanding the change characteristic of viscosity.

  11. 关于w-al-CL空间%On w-al-CL Spaces

    Institute of Scientific and Technical Information of China (English)

    林丽琼; 张云南

    2011-01-01

    给出w-al-CL空间的定义,比较几种CL性的关系,讨论w-al-CL空间的c0和与l1和的稳定性,并讨论C(K,X)空间的w-al-CL性.%Gives the definition of w-al-CL spaces, compare the relationship of some properties of CL, discusses the stability of c0 -sums and l1 -sums of w-al-CL spaces, and discusses the property of w-al-CL of C(K,X) spaces.

  12. Diversity Role on LMX relationships

    OpenAIRE

    Maria del Mar Bornay-Barrachina; Jaime Guerrero-Villegas

    2014-01-01

    High quality leader-member relationships (LMX) provide huge opportunities for strategic and organizational benefits (see Graen & Uhl-Bien, 1996; Liden et al., 1997). Despite the many positive effects of high LMXs, one area in need of empirical investigation is evidence of what leads to higher and lower quality relationships (Uhl-Bien, et al., 2000). The present analyses the antecedents of LMX, following the similarity-attraction paradigm at the dyad and at the team level, and specifically exp...

  13. Al-Anon and recovery.

    Science.gov (United States)

    Cermak, T L

    1989-01-01

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

  14. Sensorineural hearing loss in high school teenagers in Mexico City and its relationship with recreational noise Las alteraciones auditivas de escolares adolescentes en la Ciudad de México pueden estar relacionadas al ruido recreativo

    Directory of Open Access Journals (Sweden)

    María del Consuelo Martínez-Wbaldo

    2009-12-01

    Full Text Available The aim of this study was to measure the frequency of hearing loss in a sample of typical public high-school students exposed to recreational noise, and determine associated risk factors. The sample was made up of 214 teenagers from a high-school in Mexico City; subjects were selected randomly per strata. We applied a questionnaire to identify risk factors for hearing loss and performed a battery of audiologic tests consisting of otoscopy, tympanometry, and pure-tone audiometry. The mean age of the sample was 16 ± 1.07 years; 73% were male and 27%, female. Hearing loss was found in 21% of students. The main hearing loss-related risk factor was exposure to recreational noise: frequent attendance at discotheques and pop-music concerts; use of personal stereos; and noise exposure in school workshops. The high frequency of hearing loss in high school students from one Mexico City school (nearly one fifth of the sample was found to be related to noise exposure mainly during recreational activities.El objetivo de este estudio fue medir la frecuencia de alteraciones auditivas en una muestra de escolares de educación media superior expuestos a ruido recreativo y determinar algunos factores de riesgo asociados. La muestra estuvo constituida por 214 adolescentes de una escuela de la Ciudad de México. Los sujetos fueron seleccionados al azar por medio de una computadora. Se aplicaron cuestionarios con el objeto de identificar los factores de riesgo para alteraciones auditivas y se les practicaron diversos estudios audiológicos consistentes en: otoscopía, timpanometría y una audiometría a tonos puros. La edad media de la muestra fue de 16 ± 1,07 años, 73% fueron del sexo masculino y 27% femenino. Se encontraron alteraciones auditivas en 21% de los estudiantes. Los principales factores de riesgo asociados a alteraciones auditivas fueron: exposición al ruido recreativo al asistir a discotecas, conciertos de música popular, el uso de equipos de

  15. Relación entre salud y renuncia al empleo en trabajadoras de la industria maquiladora electrónica de Tijuana The relationship between health and quitting work among electronic industry female workers in Tijuana

    Directory of Open Access Journals (Sweden)

    Sylvia Guendelman

    1999-07-01

    Full Text Available OBJETIVO. Analizar factores de salud, laborales y sociales que contribuyen a renunciar al trabajo en dos maquiladoras transnacionales del ramo electrónico de Tijuana. MATERIAL Y MÉTODOS. Se realizó un estudio de cohorte a 725 mujeres empleadas en una planta japonesa y una estadunidense, entre enero de 1992 y marzo de 1994. La muestra se estratificó en dos intervalos de tiempo ­30 y >30 días laborados. Se efectuó un seguimiento de las mujeres hasta su renuncia o final del periodo de observación, mediante la recolección de información sobre variables de salud, sociales y ocupacionales de diversas fuentes de registro obtenidas de su centro de trabajo. Los motivos de renuncia y la confiabilidad de los datos obtenidos de los registros se estudiaron por medio de entrevistas de seguimiento realizadas a 46% (n= 148 de las trabajadoras que renunciaron y fueron localizadas aproximadamente 12 meses (desviación estándar= 6.7 después de su renuncia. RESULTADOS. La probabilidad acumulativa de renunciar al trabajo fue de 67% en el primer año y de 81% en el segundo. La ausencia de antecedentes laborales previos, turno diurno y nacionalidad de la compañía, resultaron factores predictivos para la renuncia al empleo durante los primeros 30 días. Tabaquismo, antecedentes quirúrgicos y haberse incapacitado por enfermedad general, después de controlar por otras variables, actuaron como factores predictivos para la renuncia posterior a 30 días. En contraposición, la tasa de renuncia posterior a 30 días resultó menor para mujeres con enfermedades crónicas. CONCLUSIONES. La renuncia al empleo en las maquiladoras es elevada y selectiva; en tanto que los factores ocupacionales se asociaron con la renuncia temprana, los relacionados con la salud fueron mejores factores predictivos para la renuncia posterior a los primeros 30 días.OBJECTIVE. To examine the health, labor and social factors which contribute to quitting work in two transnational

  16. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    ... benefit of 16 months before onset of severe respiratory failure. Other treatments are designed to relieve symptoms and ... of ALS. Most people with ALS die from respiratory failure, usually within 3 to 5 years from the ...

  17. Determination of Al Composition in Strained AlGaN Layers

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  18. TEMPERATURE DEPENDENCE OF VISCOSITY OF Al-Si ALLOY MELTS

    Institute of Scientific and Technical Information of China (English)

    H.R. Geng; R. Wang; Z.X. Yang; J.H. Chen; C.J. Sun; Y. Wang

    2005-01-01

    The relationship between the viscosity and temperature of Al-Si alloy melts was investigated.The viscosity of three different types of Al-Si alloy melts was measured. It was showed that the relationship between the viscosity and temperature of hypoeutectic Al-5% Si and eutectic Al12.5%Si alloy melts is approximately exponential except for some special zones, but that of the hypereutectic melt is different. The paper discussed the correlation of the viscosity and atomic density, which is thought that the viscosity corresponds to the atomic density to some extent.

  19. Responses of two températe evergreen Nothofagus species to sudden and gradual waterlogging: relationships with distribution patterns Respuestas de dos especies siempreverdes de Nothofagus al anegamiento gradual y repentino: relaciones con patrones de distribución

    Directory of Open Access Journals (Sweden)

    FRIDA PIPER

    2008-06-01

    érdida foliar y reducida SLA podrían excluir a esta especie de sitios muy húmedos. Concluimos que la tolerancia puede predecirse mejor desde respuestas al anegamiento gradual, más que al anegamiento repentino.

  20. Química del Oxígeno en el eutéctico 44.5% Plomo 55.5% Bismuto fundido. Aplicación a reactores ADS

    OpenAIRE

    Verdaguer Ferrer, Ariadna

    2012-01-01

    a gestió dels residus nuclears de vida llarga i alta activitat és una de les principals preocupacions al voltant de l’energia nuclear. En el marc del projecte europeu IP EUROTRANS (EURATOM 6th Framework Programme) i dels projectes espanyols COMETA (ENE2005-08611-C02-02) i COPLOGEN (ENE2009-14223-C02-02) s’ha proposat utilitzar reactors ADS (Accelerator Driven Systems) per a transmutar aquest tipus de residus. En aquest tipus de residus, protons d’alta energia, col•lisionarien amb el blanc d’e...

  1. Volver al desarrollo

    Directory of Open Access Journals (Sweden)

    Jaime Ornelas Delgado

    2012-01-01

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

  2. Nutritional assessment of very low birth weight infants: relationships between anthropometric and biochemical parameters Evaluación nutricional de lactantes de muy bajo peso al nacimiento: relaciones entre los parámetros antropométricos y bioquímicos

    Directory of Open Access Journals (Sweden)

    L. E. Monteiro Bigélli Cardoso

    2007-06-01

    Full Text Available Objective: Analyze the importance of biochemical data and their relationship with anthropometric data in the longitudinal nutritional assessment of very low birth weight infants. Methods: A prospective cohort study was performed on 55 very low birth weight preterm infants (birth weight Objetivo: Analizar la importancia de los datos bioquímicos y su relación con los datos antropométricos en la evaluación nutricional longitudinal de los lactantes de muy bajo peso al nacimiento. Métodos: Se realizó un estudio de cohortes prospectivo en 55 lactantes prematuros de muy bajo peso al nacimiento (peso al nacer < 1.500 g y < 37 semanas de edad gestacional. Se realizaron mediciones del peso, longitud, las circunferencias cefálica y de la mitad del brazo, el cociente circunferencia de la mitad del brazo: circunferencia cefálica,índice ponderal y el índice de masa corporal. Como parámetros bioquímicos se midieron la prealbúmina sérica y la proteína fijadora de retinol. Todas las variables se recogieron al nacimiento y a los 14 y 28 días de vida. Resultados: El peso medio al nacimiento de los lactantes fue de 1,076,7 ± 286 g y la edad gestacional media de 30,7± 2,1 semanas. Al nacimiento, el promedio de la prealbúmina sérica fue de 7,0 ± 1,7 mg/dl y de la proteína fijadora de retinol fue de 1,3 ± 0,4 mg/dl. Hubo una elevación significativa de todas las variables estudiadas desde el nacimiento hasta el día 28. De acuerdo con la idoneidad nutricional, no hubo diferencias entre los lactantes con edad gestacional adecuada y aquellos con edad gestacional pequeña ni en los parámetros antropométricos ni en los bioquímicos. Las medidas antropométricas no se correlacionaban con las medidas bioquímicas. Las concentraciones de proteínas séricas se convirtieron a masa de proteína sérica (MPS como sigue: MPS = concentración de proteína sérica x (100 x peso x (1 - hematocrito, puesto que las proteínas estudiadas son principalmente

  3. Jalta als Heterotopie

    OpenAIRE

    Schmid, Ulrich

    2013-01-01

    Jalta ist ein Ort, der sich im europäischen Kulturgedächtnis sowohl historisch als auch literarisch als "radikal anderer Ort" - als " Heterotopie" - festgesetzt hat. An der Konferenz von Jalta wurde 1945 eine neue Weltordnung geschaffen in der Hoffnung auf eine bessere Welt. Auch in den Werken von Anton ?echov, vor allem in denjenigen, die in Jalta entstanden sind, wird von einer anderen und besseren Welt geträumt.

  4. Pornographie als Metapher

    OpenAIRE

    Caroline Schubarth

    2010-01-01

    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...

  5. 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.

  6. Gezondheid als marketinginstrument

    NARCIS (Netherlands)

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

    2008-01-01

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

  7. Al-Anon/Alateen

    Science.gov (United States)

    Find an Al-Anon meeting Español | Français 2018 Int'l Convention Home About Group Meetings What If I'm not ready ... a meeting? What can I expect at an Al-Anon meeting? What was my first meeting like? ...

  8. Strain Rates and Grain Growth in Al 5754 and Al 6061 Friction Stir Spot Welds

    Science.gov (United States)

    Gerlich, A.; Yamamoto, M.; North, T. H.

    2007-06-01

    The stir zone temperature and microstructures are compared in friction stir spot welds produced in Al 5754 and Al 6061 alloys. Electron backscattered diffraction was used to determine the relationship between tool rotation speed during welding and final stir zone grain size. Comparison of the grain sizes in rapidly quenched welds with those in air-cooled joints confirmed that grain growth occurred only in Al 6061 spot welds. There was no evidence of abnormal grain growth in the stir zones of Al 6061 welds; the final grain size could be represented using an Arrhenius equation. The strain rates during welding were determined by incorporating the stir zone temperature and average subgrain sizes in quenched spot welds in the Zener-Hollomon relation. When the tool rotation speed increased from 750 to 3000 RPM, the strain rate values ranged from 180 to 497 s-1 in Al 5754 spot welds and from 55 to 395 s-1 in Al 6061 spot welds. It is suggested that a no-slip boundary condition may be appropriate during numerical modeling of Al 5754 and 6061 friction stir spot welding. This is not the case during Al 7075, Al 2024, and Mg-alloy AZ91 spot welding because spontaneous melting facilitates slippage at the tool contact interface.

  9. Al - BASED CAST COMPOSITES

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Yadav

    2011-08-01

    Full Text Available The economy is very important feature nowadays in themarket. The researches are playing an important role inengineering field to increase the life of machine parts /components and decrease the cost. The compositematerials have the potential to replace widely used steeland aluminium due to their good characteristics withbetter performance. The Al-based composites have foundextensive applications in automobile industries andaerospace industries due to their increased stiffness,strength, thermal conductivity and wear resistanceproperties. A number of particulate phases have beenemployed in the Al-alloy matrix. The cast aluminiumceramicparticulate composites are finding applications inpistons, connecting rods, cylinder liner, engine cylinderblock, electrical contacts etc.The present investigation isbased on study of the effect of particulate phase on theSEM study, micro-hardness, elastic modulus, tensilestrength and the wear behaviour of Al-5 % SiC-7 % Fe,Al-10 % SiC-6 % Fe and Al-15 % SiC-5 % Fe composites.

  10. Sociale media als leermiddel

    NARCIS (Netherlands)

    Rubens, Wilfred

    2012-01-01

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

  11. MDA ALS Caregiver's Guide

    Science.gov (United States)

    ... R.D., C.N.S.D., L.D.N. Nutritionist MDA/ALS Center at Vanderbilt University Medical Center ... neurologists, physiatrists, therapists (physical, occupa- tional, speech, respiratory), nutritionists, social work- ers, pulmonologists, gastroenterologists and medical equipment ...

  12. Regionale Herkunft als Bonus

    OpenAIRE

    Kratochvil, Dr. Ruth

    2004-01-01

    Der Bio-Sektor durchlebt bewegte Zeiten. Die biologische Landwirtschaft hat sich aus der Nische herausbewegt und dafür an „Besonderheiten“ eingebüßt. Diese müssen als Zusatznutzen wiedergefunden werden.

  13. Partizipation als Ausnahmezustand

    OpenAIRE

    Korf, Benedikt

    2009-01-01

    In «Die Erfindung des Politischen» (1993) beschreibt Ulrich Beck Subpolitik als den Ort, an dem die Grenze zwischen Politik und Nichtpolitik verschwindet. Aus der zunehmenden Wirkkraft von Subpolitik erwächst die grundlegende Frage, mit welcher Legitimation diese Art von Subpolitik in die Sphäre der institutionalisierten Politik eindringt. Beck’s Subpolitik soll im Anschluss an theoretische Arbeiten von Chantal Mouffe und Giorgio Agamben als post-politische Aspiration bezeichnet werden, die e...

  14. Der Preis als Kaufbarriere?

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    2012-01-01

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

  15. Rapid solidification of undercooled Al-Cu-Si eutectic alloys

    Institute of Scientific and Technical Information of China (English)

    RUAN Ying; WEI BingBo

    2009-01-01

    Under the conventional solidification condition,a liquid aluminium alloy can be hardly undercooled because of oxidation.In this work,rapid solidification of an undercooled liquid Al,80.4Cu,13.6Si,6 ternary eutectic alloy was realized by the glass fluxing method combined with recycled superheating.The re-lationship between superheating and undercooling was investigated at a certain cooling rate of the alloy melt.The maximum undercooling is 147 K (0.18 TE).The undercooled ternary eutectic is composed of α(Al) solid solution,(Si) semiconductor and β(CuAl,2) intermetallic compound.In the (Al+Si+θ) ternary eutectic,(Si) faceted phase grows independently,while (Al) and θ non-faceted phases grow coopera-tively in the lamellar mode.When undercooling is small,only (Al) solid solution forms as the leading phase.Once undercooling exceeds 73 K,(Si) phase nucleates firstly and grows as the primary phase.The alloy microstructure consists of primary (Al) dendrite,(Al+9) pseudobinary eutectic and (Al+Si+θ) ternary eutectic at small undercooling,while at large undercooling primary (Si) block,(Al+θ) pseudo-binary eutectic and (Al+Si+θ) ternary eutectic coexist.As undercooling increases,the volume fraction of primary (Al) dendrite decreases and that of primary (Si) block increases.

  16. Relationships Economics

    OpenAIRE

    Israelsen, L. Dwight; Ratliff, Richard L.

    1999-01-01

    The concept of the importance of healthy relationships in the economic system can be traced back to Adam Smith's writings of the last quarter of the 18th century. Smith believed that self-interest, the profit motive, competition, and frequent human interaction in the marketplace, within the framework of the rule of law, would induce market participants to develop moral virtues of honesty, generosity, and trust. Sellers who failed to develop these attributes would lose customers to competitors...

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

    Institute of Scientific and Technical Information of China (English)

    姜传海; 吴建生; 王德尊

    2001-01-01

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

  18. Fortschritt als Fortschrittsdiskurs

    Directory of Open Access Journals (Sweden)

    Rainer Schmid-Zartner

    2014-12-01

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

  19. 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.

  20. Wikipedia als Referenzorgan

    OpenAIRE

    Voß, Jakob

    2006-01-01

    Wikipedia wird inzwischen von vielen Nutzern regelmäßig als Nachschlagewerk genutzt. Aufgrund des offenen Charakters der Online-Enzyklopädie, bei der sich jeder direkt beteiligen kann, ist jedoch zusätzliche Medienkompetenz notwendig, um die Qualität einzelner Wikipedia-Artikel einschätzen zu können. Im Vortrag sollen Methoden zur Beurteilung von Wikipedia-Artikeln dargestellt und die Frage beleuchtet werden, unter welchen Umständen Wikipedia als Referenzorgan geeignet ist.

  1. Carta al Editor

    Directory of Open Access Journals (Sweden)

    José Andrés Burgos Zuleta

    2010-06-01

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

  2. Preparing the care relationship: a welcoming tool in health units Preparando la relación para atender al paciente: una herramienta para el acogimiento en unidades de salud Preparando a relação de atendimento: ferramenta para o acolhimento em unidades de saúde

    Directory of Open Access Journals (Sweden)

    Silvia Matumoto

    2009-12-01

    Full Text Available This study aimed to identify and analyze aspects regarding the preparation for the worker-user relationship in a primary health care unit in a city in the state of São Paulo-Brazil, from the perspective of welcoming. The health work process is the theoretical basis of the study; participant observation and semi-structured interviews were used as data collection techniques, and thematic analysis in the analysis stage. For the welcoming to be processed, there is a "moment" of preparation for the worker, the physical environment and the relationships present at work so that users are welcomed, in which the users' needs are sometimes disregarded. Despite the difficulties in terms of resource availability, especially in the public sector, when preparing the service/user and worker/user relationships, one should consider the aspects associated to a more human, welcoming relationship, since it is during live work, in this intersection, that care quality is established.Se tuvo por objetivo identificar y analizar aspectos pertinentes a la preparación para la relación trabajador/usuario en una unidad de salud de la red de atención básica de un municipio del Estado de San Pablo, Brasil, teniendo como perspectiva el acogimiento. El proceso de trabajo en salud sustenta teóricamente el estudio. Se utilizó la observación participante y la entrevista semiestructurada como técnicas de recolección de datos y el análisis temático en la etapa de análisis. Para que el acogimiento se procese deben existir un "momento" de preparación del trabajador; debe ser preparado su espacio físico y las relaciones presentes en el trabajo para que suceda la atención al usuario, donde no siempre son consideradas sus necesidades. A pesar de que existan dificultades en la disponibilidad de recursos, especialmente en el sector público, en la preparación de la relación servicio/usuario y trabajador/usuario, deben ser considerados los aspectos vinculados a una relaci

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

    Institute of Scientific and Technical Information of China (English)

    段少飞; 陈秀敏; 杨斌; 郁青春; 徐宝强; 刘大春

    2015-01-01

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

  4. TEM study of the initial oxide scales of Ti2AlC

    NARCIS (Netherlands)

    Rao, J.C.; Pei, Y.T.; Yang, Huajie; Song, G.M.; Li, S.B.; Hosson, J.Th.M. De

    2011-01-01

    This paper presents a detailed microstructural analysis of the crystallographic relationships between alpha-Al2O3 oxide scale and Ti2AlC parent material, and examines the atomic diffusion and formation of oxide scale on Ti2AlC during the initial oxidation stage at 1200 degrees C. It is shown that th

  5. Comentarios al Salto Social

    Directory of Open Access Journals (Sweden)

    Facultad de Ciencias Económicas

    1995-06-01

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

  6. Slowenisch als fremdsprache

    Directory of Open Access Journals (Sweden)

    Jože Toporišič

    1981-12-01

    Full Text Available Nicht ganz zwei Millionen Menschen sprechen Slowenisch als Muttersprache. Wenige gibt es, die das Slowenische zwar spre­ chen oder zu sprechen versuchen, aber eine andere Muttersprache haben, vielleicht hunderttausend; für die ist Slowenisch also eine Fremdsprache.

  7. The Byzantines in Medieval Arabic Poetry: Abu Firas’ "Al-Rumiyyat" and the Poetic Responses of al-Qaffal and Ibn Hazm to Nicephore Phocas’ "Al-Qasida al-Arminiyya al-Malʿuna" (The Armenian Cursed Ode

    Directory of Open Access Journals (Sweden)

    Nizar F. HERMES

    2009-10-01

    Full Text Available Up until the Crusades, it was al-Rūm who were universally seen by Arab writers and Arab poets in particular as the Other par excellence. Nowhere is this more conspicuous than in the sub-genre of Al-Rūmiyyat (poems about the Byzantines, namely as found in the Rūmiyyat of Abu Firas al-Hamdani(d.968, and in the poetic responses of al-Qaffal(d. 946 and Ibn Hazm(d. 1064 to what was described by several medieval Muslim chronicles as Al-Qasida al-Arminiyya al-Malʿuna (The Armenian Cursed Ode. By exploring the forgotten views of the Byzantines in medieval Arabic poetry, this article purports to demonstrate that contrary to the impression left after reading Edward Said’s groundbreaking Orientalism: Western Conceptions of the Orient (1978 and other postcolonial studies, Orientals have not existed solely to be ‘orientalized’. Perhaps even before this came to be so, they too had ‘occidentalized’ their Euro-Christian Other(s in a way that mirrored in reverse the subject/object relationship described as Orientalism.

  8. Relação de ajuda no desempenho dos cuidados de enfermagem a doentes em fim de vida Relacíon de ayuda en el contexto de los cuidados de enfermeria a enfermos al final de su vida Helping relationship in end-of-life patient's nursing care context

    Directory of Open Access Journals (Sweden)

    Rosa Maria Pereira Simões

    2010-09-01

    Full Text Available Este estudo tem como principal objetivo verificar a importância que os enfermeiros atribuem às competências relacionais na ajuda a doentes em fim de vida. A investigação é de tipo descritivo-correlacional, transversal, com uma amostra de 56 enfermeiros, selecionada de forma intencional, acidental e desenvolvida a partir da aplicação de um instrumento de medida que integra o Inventário de Competências Relacionais de Ajuda, Escala de Satisfação com a Vida, Questões relativas à importância atribuída à formação contínua. Da análise dos resultados ressalta-se que os enfermeiros consideram as competências relacionais fundamentais para o cuidado ao doente em fim de vida. O desempenho de competências relacionais de ajuda está significativamente correlacionado com a formação que os enfermeiros desenvolveram sobre relação de ajuda, bem como com a satisfação que têm com a vida em geral.Este estudio tiene como principal objetivo comprobar la importancia que conceden los enfermeros a las competencias de relacionamiento, en la ayuda a enfermos al final de su vida. La investigación es de tipo descriptivo y de correlación, transversal, con una muestra de 56 enfermeros, seleccionada de forma intencional, accidental y desarrollada a partir de la aplicación de un instrumento de medida integrado en el Inventario de competencias relacionales de ayuda, Escala de satisfacción con la vida, cuestiones referentes a la importancia concedida a la formación continua. Del análisis de los resultados concluimos que los enfermeros consideran las competencias de relacionamiento fundamentales para cuidar al enfermo al final de su vida. Los resultados indican que el mejor resultado de competencias de relacionamiento, por parte de los enfermeros, está correlacionado con mejor formación sobre relación de ayuda, así como la percepción de mayor satisfacción con la vida en general. Estos resultados tienen aplicación en el proceso de

  9. Digital Relationships

    DEFF Research Database (Denmark)

    Ledborg Hansen, Richard

    -­rich information and highly interesting communication are sky-­high and rising. With a continuous increase in digitized communication follows a decrease in face-­to-­face encounters and our ability to engage in inter-­personal relationships are suffering for it (Davis, 2013). The behavior described in this paper......-­‐Jones, 2011) for increases in effectiveness and efficiency we indiscriminately embrace digital communication and digitized information dissemination with enthusiasm – at the risk of ignoring the potentially dark side of technology. However, technology also holds a promise for better understanding precisely...... for the same reasons – that the growing amount of digitized communication “out there” represents data waiting to be sifted, analyzed and decoded. In this paper “Facebook behavior” refers to a particular behavior characterized by presenting your self and representations of selected self in the hope of getting...

  10. Thermodynamic watershed hydrological model: Constitutive relationship

    Institute of Scientific and Technical Information of China (English)

    TIAN FuQiang; HU HePing; LEI ZhiDong

    2008-01-01

    The representative elementary watershed (REW) approach proposed by Reggiani et al. Was the first attempt to develop scale adaptable equations applicable directly at the macro scale. Tian et al. Extended the initial definition of REW for simulating the energy related processes, and re-organized the deriving procedure of balance equations so that additional sub-regions and substances could be easily incorpo- rated. The resultant ordinary differential equation set can simulate various hydro- logical processes in a physically reasonable way. However, constitutive and geo- metric relationships have not been developed for Tian et al.'s equation set, which are necessary for the thermodynamic watershed hydrological model to apply in hydrological modeling practice. In this work, the constitutive equations for mass exchange terms and momentum exchange terms were developed as well as geo- metric relationships. The closed ordinary differential equation set with nine equations was finally obtained.

  11. Efecto del tabaquismo durante el embarazo sobre la antropometría al nacimiento Effect of smoking during pregnancy on anthropometric characteristics at birth

    Directory of Open Access Journals (Sweden)

    Luisa María Sánchez-Zamorano

    2004-12-01

    Full Text Available OBJETIVO: Evaluar el efecto del consumo de tabaco durante el embarazo sobre el peso y la longitud al nacimiento. MATERIAL Y MÉTODOS: Mediante el análisis secundario de una base de datos de dos estudios de cohorte, realizados en la Ciudad de México de 1993 a 2000 sobre exposición a plomo, se evaluaron las diferencias en el peso y longitud al nacer entre los hijos de mujeres que refirieron haber fumado durante el embarazo y las que no lo hicieron. Las diferencias se estimaron ajustando por otros factores importantes para el peso y la longitud al nacer, mediante modelos de regresión lineal múltiple. RESULTADOS: La proporción de mujeres que dijeron fumar durante el embarazo fue de 4.7%. Se observó que los hijos de madres que fumaron durante el embarazo pesaron en promedio 154 gramos menos (IC 95% -284.7 -24.7, y midieron 0.79 centímetros menos (IC 95% -1.5 -0.1, en comparación con los hijos de mujeres que refirieron no haber fumado durante el embarazo. CONCLUSIONES: Estos hallazgos ponen en evidencia el daño producido por el consumo de tabaco sobre la población infantil.OBJECTIVE: To assess the effect of tobacco consumption during pregnancy on height and birth weight of newborns. MATERIAL AND METHODS: Two cohort studies on lead exposure conducted in Mexico City between 1993 and 2000 were analyzed. Data were analyzed to assess the differences in height and birth weight between children of women who smoked during pregnancy and those who did not, adjusting for other important factors. Statistical analysis consisted of multiple linear regression models. RESULTS: The proportion of women who smoked during pregnancy was 4.7%. The birth weight of children of mothers who smoked during pregnancy was 154 grams less on average (95% confidence interval [CI] -284.7, -24.7 and their height was 0.79 cm less (95% CI -1.5, -0.1 than the children of non-smokers during pregnancy. CONCLUSIONS: These findings evidence the deleterious effect of tobacco

  12. Synthesis, Microstructure, and Property of Cr2AlC

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cr2AlC is an unusual layered ternary ceramic that combines the merits of both metals and ceramics. The salient properties of Cr2AlC are strongly related to its bonding characteristics and microstructures. Synthesis,microstructure, and property of Cr2AlC are reviewed in this paper. First, theoretical calculations and physical properties are introduced. Then, the processing of Cr2AlC ceramic in both bulk form and thin films and their basic mechanical properties are summarized. Atomic-scale characterizations of Cr2AlC, as well as the microstructural relationships among Cr2AlC, Al8Cr5, and AlCr2 were achieved using a series of transmission electron microscopy (TEM) techniques. Moreover, high-temperature oxidation and hot corrosion behaviors of Cr2AlC were investigated by means of thermogravimetric analysis, X-ray diffraction, Raman spectroscopy,scanning electron microscopy, and TEM. Mechanism of the excellent high-temperature corrosion resistance of Cr2AlC is discussed based on systematic microstructural analyses. Finally, concise conclusions are drawn.

  13. ALS insertion devices

    International Nuclear Information System (INIS)

    The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system. 18 refs., 9 figs., 5 tabs

  14. De GPS al mapa

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

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

  15. AL-IZDIWAJIYYAH AL-LUGHOWIYAH FII ISTIHDHAMI AL-LUGHOH AL-‘ARABIYAH

    OpenAIRE

    Imam Muslimin

    2011-01-01

    Al-Izdiwajiyyah (diglosia) is standardizing a specific language when there are two variants of language that live side by side in societal life and each variant has its own social function. Disglosia is related to the use of local languages variations of low language and high language in a community. In Arabic language, disglosia covers dialects among the speakers, for instance there are two variants of language that each has roles and functions. The use of the variant depends on the situatio...

  16. Carta al editor

    Directory of Open Access Journals (Sweden)

    Harry Pachajoa

    2012-02-01

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

  17. Carta al editor

    OpenAIRE

    Harry Pachajoa

    2012-01-01

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

  18. FeAl and NbAl3 Intermetallic-HVOF Coatings: Structure and Properties

    Science.gov (United States)

    Guilemany, J. M.; Cinca, N.; Dosta, S.; Cano, I. G.

    2009-12-01

    Transition metal aluminides in their coating form are currently being explored in terms of resistance to oxidation and mechanical behavior. This interest in transition metal aluminides is mainly due to the fact that their high Al content makes them attractive for high-temperature applications. This is also a reason to study their resistance to wear; they may be suitable for use in applications that produce a lot of wear in aggressive environments, thus replacing established coating materials. In this study, the microstructure, microhardness, and wear and oxidation performance of FeAl and NbAl3 coatings produced by high-velocity oxy-fuel spraying are evaluated with two main aims: (i) to compare these two coating systems—a commonly studied aluminide (FeAl) and, NbAl3, an aluminide whose deposition by thermal spraying has not been attempted to date—and (ii) to analyze the relationship between their microstructure, composition and properties, and so clarify their wear and oxidation mechanisms. In the present study, the higher hardness of niobium aluminide coatings did not correlate with a higher wear resistance and, finally, although pesting phenomena (disintegration in oxidizing environments) were already known of in bulk niobium aluminides, here their behavior in the coating form is examined. It was shown that such accelerated oxidation was inevitable with respect to the better resistance of FeAl, but further improvements are foreseen by addition of alloying elements in that alloy.

  19. Critical and Impeding Pressures of Al Evaporation during ISM Processing of NiAl

    Institute of Scientific and Technical Information of China (English)

    Guizhong LIU; Jingjie GUO; Yanqing SU; Jingzhe GUO; Jun JIA; Hengzhi FU

    2003-01-01

    In this paper, the critical pressure Pcrit and impeding pressure Pirnpe of the elemental evaporation were defined and studied based on the calculation of the relationship between the evaporation loss rate Nm and the chamber pressure p during melting of NiAl alloys. When the chamber pressure is lower than Perit or higher than Pimpe, Nm tends to be the maximum or minimum value and remains almost unchanged. However, declines sharply with the increase of the chamber pressure when Pcrit<P<Pimpe. A method has been put forward to calculate the Pcrit and Pimpe of Al evaporation in a Ni-XAl (X=25~50 at. pct) melt. The calculation result shows that the pcrit or Pimpe is a second-order function of the molar percentage of Al and the melting temperature.

  20. Semi-solid Processing of Al-7Graghite Composite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Al-7graphite composite was processed using Al-7graphite mush y prepared by electromagnetic-mechanical stirring method, and the infl uence of solid fraction on the distributing of graphite particles in i ngot was studied. The results shows that the relationship between soli d fraction and stirring temperature of mushy is: =591.50.897 (where i s the solid fraction, is the stirring temperature). For Al-7graphite composite, with the increasing of solid fraction, the aggregation exte nt of graphite particles reduced gradually, and when solid fraction wa s larger than 30%, graphite particles could distribute evenly in ingot .

  1. Relationship among social support, treatment adherence and metabolic control of diabetes mellitus patients Relación entre apoyo social, adhesión al tratamiento y control metabólico de personas con Diabetes Mellitus Relação entre apoio social, adesão aos tratamentos e controle metabólico de pessoas com diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Lilian Cristiane Gomes-Villas Boas

    2012-02-01

    Full Text Available This cross-sectional and quantitative study aimed to analyze the relationship among social support, adherence to non-pharmacological (diet and physical exercise and pharmacological treatments (insulin and/or oral anti-diabetic medication and clinical and metabolic control of 162 type 2 diabetes mellitus patients. Data were collected through instruments validated for Brazil. Social support was directly correlated with treatment adherence. Adherence to non-pharmacological treatment was inversely correlated with body mass index, and medication adherence was inversely correlated with diastolic blood pressure. There were no associations between social support and clinical and metabolic control variables. Findings indicate that social support can be useful to achieve treatment adherence. Studies with other designs should be developed to broaden the analysis of relations between social support and other variables.El presente estudio objetivó analizar la relación entre apoyo social, adhesión a los tratamientos no medicamentoso (dieta y ejercicio físico y medicamentoso(insulina y/o antidiabéticos orales y control clínico-metabólico de 162 personas con diabetes mellitus tipo 2. Se trata de un estudio seccional, de abordaje cuantitativo. Los datos fueron recolectados por medio de instrumentos validados. El apoyo social tuvo correlación directa con la adhesión al tratamiento. Se observó correlación inversa entre adhesión al tratamiento no medicamentoso y índice de masa corporal, así como entre adhesión medicamentosa y presión arterial diastólica. No hubo asociaciones entre apoyo social y variables de control clínico-metabólico. Se concluye que el apoyo social podrá ser útil para obtener la adhesión a los tratamientos. Estudios con otros delineamientos deben ser desarrollados, a fin de ampliar el análisis de las relaciones entre apoyo social y otras variables.O presente estudo objetivou analisar a relação entre apoio social, ades

  2. High temperature oxidation of beta-NiAl

    Science.gov (United States)

    Koychak, J. K.; Mitchell, T. E.; Smialek, J. L.

    1985-01-01

    The oxidation of single crystal beta-NiAl has been studied primarily using electron microscopy. Oriented metastable Al2O3 phases form during transient oxidation at 800 C. Specific orientation relationships exist on all metal orientations studied and are a result of the small mismatch along aligned close-packed directions in the cation sublattices of the metal and oxide. Transformation of the metastable Al2O3 phases at 1100 C results in an oxide morphology described as the 'lacey' structure of alpha-Al2O3 scales. This structure results from impingement of oriented patches of alpha-Al2O3 as the transformation initiates and moves radially parallel to the surface. Scale growth occurs by diffusion along high angle grain boundaries. A drastic reduction in oxidation rate accompanies the change in oxide morphology.

  3. Modeling neuronal vulnerability in ALS.

    Science.gov (United States)

    Roselli, Francesco; Caroni, Pico

    2014-08-20

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

  4. 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...

  5. ICT als medicijn tegen onveiligheid

    OpenAIRE

    Linders, Lilian; Steyaert, Jan

    2002-01-01

    Hoe verhoudt ICT zich tot veiligheid? SQM zou niet 'ict oplossingen voor sociale kwesties' als ondertitel hebben, als we geen aandacht gaven aan deze vraag. In de eerste Rode Draad Notitie verkent SQM dit thema.

  6. Into the dark heart of ethnography: The lived ethics and inequality of intimate field relationships En el oscuro corazón de la etnografía. Ética y desigualdades en las relaciones íntimas al interior del campo

    Directory of Open Access Journals (Sweden)

    Katherine Irwin

    2008-07-01

    Full Text Available

     

    In this paper, I reflect on some of the debates regarding intimacy and exploitation by examining my relationship with my key informant. I trace the way that, despite my attempts to follow the existing ethical guides, I reinforced several larger inequalities in my intimate stance. I argue that our discussions of intimate methods and immersion in the field have failed to accurately note how we reinforce or resist structure in our research endeavours. Viewing ourselves as “doing structure” in the field would lead us to stop debating whether intimacy is better than objectivity, celibacy is better than sex, disclosure is better than silence, or conventional behaviour is better than deviance in the field. Instead, we should locate how our behaviours, research roles, or discursive choices enact structures and the effect this enactment has on the people who we research.

    En este artículo, reflejo algunos de los debates con respecto a la intimidad y explotación examinando mi relación con mi informante clave. Recorro la manera en que, a pesar de mis intentos de seguir las guías éticas existentes, reforcé varias y grandes desigualdades en mi postura íntima. Sostengo que nuestras discusiones sobre métodos íntimos y la inmersión en el campo han fallado al observar adecuadamente cómo reforzamos o resistimos la estructura en nuestros esfuerzos de investigación. Vernos a nosotros mismos como “haciendo estructura” en el campo nos llevaría a parar el debate sobre si la intimidad es mejor que la objetividad, si el celibato es mejor que el sexo, si la revelación es mejor que silencio, o si el comportamiento convencional es mejor que el desvío en el campo. En lugar de eso, debemos localizar cómo nuestros comportamientos, roles en la investigación, u opciones discursivas representan estructuras y el efecto que esta representación tiene en la gente que investigamos.

  7. Gliricidia sepium al establecimiento

    Directory of Open Access Journals (Sweden)

    J. L. Valle

    2004-01-01

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

  8. Derivados vinculados al seguro.

    Directory of Open Access Journals (Sweden)

    De Paz Cobo, Sonia

    2003-01-01

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

  9. Effects of the Formation of Al x Cu y Gradient Interfaces on Mechanical Property of Steel/Al Laminated Sheets by Introducing Cu Binding-Sheets

    Science.gov (United States)

    Wei, Aili; Liu, Xinghai; Shi, Quanxin; Liang, Wei

    2015-07-01

    Steel/Cu/Al laminated sheets were fabricated by two-pass hot rolling to improve the mechanical properties of steel/Al sheets. The bonding properties and deformability of the steel/Cu/Al sheets were studied. Steel/Al and steel/Cu/Al samples were rolled at 350°C for 15 min with the first-pass reduction of 40%, and then heated at 600°C for 5 min with different reductions. It was found that the steel/Cu/Al samples rolled by the second-pass reduction of 85% could endure the maximum 90° bend cycle times of 45, exhibiting excellent fatigue resistance as well as deformability. The steel/Al samples could only reach the maximum 90° bend cycle times of 20. Furthermore, the scanning electron microscope, energy-dispersive spectrometer, and electron backscattered diffraction results showed that the preferred growth orientations of Cu, Al4Cu9, and Al2Cu on the steel/Cu/Al laminated sheets are {-1, 1, 2} , {1, 0, 0} and {-1, 1, 2} {1, 1, 0} . The orientation relationships between Cu and Al2Cu are {1, 1, 0}(fcc)//{1, 1, 0}(bct) and {1, 1, 1}(fcc)//{1, 1, 1}(bct). The improved bonding property and excellent fatigue resistance as well as deformability were mainly ascribed to the tight combination and consistent deformability across steel, Al, and the transition layers (Cu, Al4Cu9, and Al2Cu).

  10. Ratio of Fe-Al compound at interface of steel-backed Al-graphite semi-solid bonding plate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; DU Yun-hui; LIU Han-wu; ZHANG Jun; ZENG Da-ben; BA Li-min

    2007-01-01

    The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interfacial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters (such as preheat temperature of steel plate. solid fraction of Al-7graphite slurry and rolling speed) was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed.the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%.This reasonable ratio of Fe-Al compound is a quantitative criterion of interfacial embrimement, namely, when the ratio of Fe-Al compound at intefface is larger than 70.1%.interfacial embrittlement will occur.

  11. Corrosion behaviour of Al/SiC and Al/Al2O3 nanocomposites

    Directory of Open Access Journals (Sweden)

    Tamer Samir Mahmoud

    2012-12-01

    Full Text Available In the present investigation, the static immersion corrosion behavior of Al/Al2O3 and Al/SiC nanocomposites in 1 M HCl acidic solution was evaluated. The nanocomposites were fabricated using conventional powder metallurgy (P/M route. The effect of nanoparticulates size and volume fraction on the corrosion behavior of nanocomposites was studied. The durations of the corrosion tests ranged from 24 to 120 hours and the temperatures of the solution ranged from ambient to 75 ºC. The corrosion rates of the nanocomposites were calculated using the weight loss method. The results showed that both Al/SiC and Al/Al2O3 MMNCs have lower corrosion rates than the pure Al matrix. Such behavior was noticed at both ambient and higher temperatures. Generally, the Al/Al2O3 nanocomposites exhibited lower corrosion rates than the Al/SiC nanocomposites. The Al/Al2O3 (60 nm nanocomposites exhibited the highest corrosion resistance among all the investigated nanocomposites. The corrosion rate was found to be reduced by increasing of the exposure time and the volume fraction of the nanoparticulates, while it was found to be increased by increasing of the nanoparticulates size and the solution temperature.

  12. Doppelthydrophile Blockcopolymere als Mineralisationstemplate

    Science.gov (United States)

    Kasparova, Pavla

    2002-07-01

    Die vorliegende Arbeit beschäftigt sich mit der Synthese und den Eigenschaften von doppelthydrophilen Blockcopolymeren und ihrer Anwendung in einem biomimetischen Mineralisationsprozeß von Calciumcarbonat und Bariumsulfat. Doppelthydrophile Blockcopolymere bestehen aus einem hydrophilen Block, der nicht mit Mineralien wechselwirkt und einem zweiten Polyelektrolyt-Block, der stark mit Mineraloberflächen wechselwirkt. Diese Blockcopolymere wurden durch ringöffnende Polymerisation von N-carboxyanhydriden (NCA's) und a-methoxy-ω-amino[poly(ethylene glycol)] PEG-NH2 als Initiator hergestellt. Die hergestellten Blockcopolymere wurden als effektive Wachstumsmodifikatoren für die Kristallisation von Calciumcarbonat und Bariumsulfat Mineralien eingesetzt. Die so erhaltenen Mineralpartikel (Kugeln, Hantel, eiförmige Partikel) wurden durch Lichtmikroskopie in Lösung, SEM und TEM charakterisiert. Röntgenweitwinkelstreuung (WAXS) wurde verwendet, um die Modifikation von Calciumcarbonat zu ermitteln und die Größe der Calciumcarbonat- und Bariumsulfat-Nanopartikel zu ermitteln. This work describes the synthesis and characterization of double hydrophilic block copolymers and their use in a biomimetic mineralization process of Calcium Carbonate and Barium Sulfate. Double hydrophilic block copolymers consist of a hydrophilic block that does not interact with minerals and another hydrophilic polyelectrolyte block that strongly interacts with mineral surfaces. These polymers were synthesised via ring opening polymerisation of N-carboxyanhydride (NCA), and the first hydrophilic block a-methoxy-ω-amino[poly(ethylene glycol)] PEG-NH2 was used as an initiator. The prepared block copolymers were used as effective crystal growth modifiers to control the crystallization of Calcium Carbonate and Barium Sulfate minerals. The resulting mineral particles (spheres, dumbbells, egg-like particles) were characterised by light microscopy in solution, by SEM, and by TEM. X-Ray scattering

  13. COMENTARIO AL CASO PINOCHET

    Directory of Open Access Journals (Sweden)

    Alberto Contreras Clunes

    2002-01-01

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

  14. Epitaxial growth of Al/Al2O3 multilayer structures

    International Nuclear Information System (INIS)

    In order to obtain Al-Al2O3 quantum effect devices, it is necessary to deposit epitaxially Al on Al2O3 and Al2O3 on Al. We have already obtained an epitaxial Al/Al2O3/Al structures on Si(111). In this paper, we have deposit Al/Al2O3/Al structures on Si(111), and investigated the crystallinity by using RBS. (author)

  15. Thermodynamic watershed hydrological model: Constitutive relationship

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The representative elementary watershed (REW) approach proposed by Reggiani et al. was the first attempt to develop scale adaptable equations applicable directly at the macro scale. Tian et al. extended the initial definition of REW for simulating the energy related processes, and re-organized the deriving procedure of balance equations so that additional sub-regions and substances could be easily incorpo-rated. The resultant ordinary differential equation set can simulate various hydro-logical processes in a physically reasonable way. However, constitutive and geo-metric relationships have not been developed for Tian et al.’s equation set, which are necessary for the thermodynamic watershed hydrological model to apply in hydrological modeling practice. In this work, the constitutive equations for mass exchange terms and momentum exchange terms were developed as well as geo-metric relationships. The closed ordinary differential equation set with nine equa-tions was finally obtained.

  16. Effect of AlN Particulate Size on Superplasticity of AlNp/6061 Al Composites

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Superplastic tensile tests of AlNp/606l Al Composites, fabricated by powder metallurgy techniques, were performed at strain rates ranging from 10-1-10-3S-1 and at temperatures from 833 to 893 K. Hot rolling after extrusion was employed to obtain a fine grained structure before \\superplastic testing. The superplastic behavior of AlNp/6061 Al Composites was compared with that of AlN particulate size. Differential scanning calorimeter was used to ascertain the possibility of any partial melting in the vicinity of optimum superplastic temperatures.

  17. Ancestral Relationships Using Metafounders

    DEFF Research Database (Denmark)

    Legarra, Andres; Christensen, Ole Fredslund; Vitezica, Zulma G;

    2015-01-01

    Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist...

  18. Editorial: Cartas al Editor

    Directory of Open Access Journals (Sweden)

    Guillermo Llanos

    2006-06-01

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

  19. 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.

  20. Influence of impact speed on water droplet erosion of TiAl compared with Ti6Al4V

    Science.gov (United States)

    Mahdipoor, M. S.; Kirols, H. S.; Kevorkov, D.; Jedrzejowski, P.; Medraj, M.

    2015-09-01

    Water Droplet Erosion (WDE) as a material degradation phenomenon has been a concern in power generation industries for decades. Steam turbine blades and the compressor blades of gas turbines that use water injection usually suffer from WDE. The present work focuses on studying erosion resistance of TiAl as a potential alloy for turbine blades compared to Ti6Al4V, a frequently used blade alloy. Their erosion behaviour is investigated at different droplet impact speeds to determine the relation between erosion performance and impact speed. It is found that the relationship is governed by a power law equation, ER ~ Vn, where the speed exponent is 7-9 for Ti6Al4V and 11-13 for TiAl. There is a contrast between the observed speed exponent in this work and the ones reported in the literature for Ti6Al4V. It is attributed to the different erosion setups and impingement conditions such as different droplet sizes. To verify this, the erosion experiments were performed at two different droplet sizes, 464 and 603 μm. TiAl showed superior erosion resistance in all erosion conditions; however, its erosion performance exhibits higher sensitivity to the impact speed compared to Ti6Al4V. It means that aggressive erosion conditions decrease the WDE resistance superiority of TiAl.

  1. AL-IZDIWAJIYYAH AL-LUGHOWIYAH FII ISTIHDHAMI AL-LUGHOH AL-‘ARABIYAH

    Directory of Open Access Journals (Sweden)

    Imam Muslimin

    2011-10-01

    Full Text Available Al-Izdiwajiyyah (diglosia is standardizing a specific language when there are two variants of language that live side by side in societal life and each variant has its own social function. Disglosia is related to the use of local languages variations of low language and high language in a community. In Arabic language, disglosia covers dialects among the speakers, for instance there are two variants of language that each has roles and functions. The use of the variant depends on the situation. The most important characteristic of diglosia is specifying the functions of wach language variant. For high level language variant is aimed for formal situations such as religious ceremony, lectures, news, or editorials of newspaper. On the contrary, the low level language variant is commonly used in less formal situation such as daily communication in the family, chat with friends, stories in radion, and folk literature. In Arabic language, diglosia can be identified when the speaker of the language use diction commonly used for daily communication (amiyah in a formal expression (fusha, and vice versa.

  2. Al versus Si competition in FeSiAl alloys

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

  3. Fragility and structure of Al-Cu alloy melts

    Energy Technology Data Exchange (ETDEWEB)

    Lv Xiaoqian [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China)]. E-mail: xfbian@sdu.edu.cn; Mao Tan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Li Zhenkuan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Guo Jing [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhao Yan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2007-04-15

    The dynamic viscosity measurements are performed for Al-Cu alloy melts with different compositions using an oscillating-cup viscometer. The results show that the viscosities of Al-Cu alloy melts increase with the copper content increasing, and also have a correlation with the correlation radius of clusters, which is measured by the high-temperature X-ray diffractometer. It has also been found that the fragilities of superheated melts (M) of hypereutectic Al-Cu alloys increase with the copper content increasing. There exists a relationship between the fragility and the structure in Al-Cu alloy melts. The value of the M reflects the variation of activation energy for viscous flow.

  4. Transient oxidation of single-crystal beta-NiAl

    Science.gov (United States)

    Doychak, J.; Smialek, J. L.; Mitchell, T. E.

    1989-01-01

    The transient oxidation of beta-NiAl in air at 800 C and 1100 C has been studied using electron microscopy. The oxide scale consists predominantly of metastable Al2O3 phases. Theta-Al2O3 is the major oxide phase within 10.0 hr of oxidation at 800 C and 0.1 hr at 1100 C. The scales form epitaxially on (001) sub beta and (012) sub beta specimens throughout the transient stage, whereas the degree of preferred oxide orientation decreases with oxidation time on (011) sub beta and (111) sub beta specimens. The orientation relationships reflect the small mismatch between parallel close-packed directions in the metal and in the cation sublattice of the oxides. The correlation of distinctive oxide surface morphologies with internal structural defects indicates the strong tendency of the Al2O3 scale to grow via short-circuit diffusion paths.

  5. Role of defect coordination environment on point defects formation energies in Ni-Al intermetallic alloys

    Science.gov (United States)

    Tennessen, Emrys; Rondinelli, James

    We present a relationship among the point defect formation energies and the bond strengths, lengths, and local coordination environment for Ni-Al intermetallic alloys based on density functional calculations, including Ni3Al, Ni5Al3, NiAl,Ni3Al4, Ni2Al3 and NiAl3. We find the energetic stability of vacancy and anti-site defects for the entire family can be attributed primarily to changes in interactions among first nearest neighbors, owing to spatially localized charge density reconstructions in the vicinity of the defect site. We also compare our interpretation of the local coordination environment with a DFT-based cluster expansion and discuss the performance of each approach in predicting defect stability in the Ni-Al system.

  6. Undulators at the ALS

    International Nuclear Information System (INIS)

    At Lawrence Berkeley Laboratory's (LBL) Advanced Light Source (ALS), three 4.6 m long undulators have been completed, tested and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 microns over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within +/- 5 microns. Gap adjusting range is from 14 mm to 210 mm, which can be scanned in one minute. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are. in the mid 10-11 Torr range and storage ring operating pressures with full current are in the low 10-10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23%, and 0.20% for the two U5.Os and the U8.0 respectively and that the field integrals are small over the 1 cm by 6 cm beam aperture. Device description, fabrication, and measurements are presented

  7. Alexandria (Al Iskandariya), Egypt

    Science.gov (United States)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

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

    Science.gov (United States)

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

    2016-09-01

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

  9. Correlative characterization of primary Al{sub 3}(Sc,Zr) phase in an Al–Zn–Mg based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, J.H., E-mail: jie-hua.li@hotmail.com [Institute of Casting Research, Montanuniversität Leoben, A-8700 Leoben (Austria); Wiessner, M. [Materials Center Leoben Forschung GmbH, A-8700 Leoben (Austria); Albu, M. [Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Center for Electron Microscopy (Austria); Wurster, S. [Department of Materials Physics, Montanuniversität Leoben, Erich Schmid Institute of Materials Science of the Austrian Academy of Sciences, A-8700 Leoben (Austria); Sartory, B. [Materials Center Leoben Forschung GmbH, A-8700 Leoben (Austria); Hofer, F. [Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Center for Electron Microscopy (Austria); Schumacher, P. [Institute of Casting Research, Montanuniversität Leoben, A-8700 Leoben (Austria); Austrian Foundry Research Institute, A-8700 Leoben (Austria)

    2015-04-15

    Three-dimensional electron backscatter diffraction, focused ion beam, transmission electron microscopy and energy filtered transmission electron microscopy were employed to investigate the structural information of primary Al{sub 3}(Sc,Zr) phase, i.e. size, shape, element distribution and orientation relationship with the α-Al matrix. It was found that (i) most primary Al{sub 3}(Sc,Zr) phases have a cubic three-dimensional morphology, with a size of about 6–10 μm, (ii) most primary Al{sub 3}(Sc,Zr) phases are located within the α-Al matrix, and exhibit a cube to cube orientation relationship with the α-Al matrix, and (iii) a layer by layer growth was observed within primary Al{sub 3}(Sc,Zr) phases. Al, Cu, Si and Fe are enriched in the α-Al matrix between the layers of cellular eutectic Al{sub 3}(Sc,Zr) phase, while Sc, Ti and Zr are enriched in small Al{sub 3}(Sc,Zr) phases. A peritectic reaction and subsequent eutectic reaction between Al{sub 3}Sc and Al was proposed to interpret the observed layer by layer growth. This paper demonstrates that the presence of impurities (Fe, Si, Cu, Ti) in the diffusion field surrounding the growing Al{sub 3}(Sc,Zr) particle enhances the heterogeneous nucleation of Al{sub 3}(Sc,Zr) phases. - Highlights: • Most fine cubic primary Al{sub 3}(Sc,Zr) phases were observed within the α-Al matrix. • A layer by layer growth within primary Al{sub 3}(Sc,Zr) phase was observed. • A peritectic and subsequent eutectic reaction between Al{sub 3}Sc and Al was proposed. • Impurities in diffusion fields enhance heterogeneous nucleation of Al{sub 3}(Sc,Zr)

  10. Correlative characterization of primary Al3(Sc,Zr) phase in an Al–Zn–Mg based alloy

    International Nuclear Information System (INIS)

    Three-dimensional electron backscatter diffraction, focused ion beam, transmission electron microscopy and energy filtered transmission electron microscopy were employed to investigate the structural information of primary Al3(Sc,Zr) phase, i.e. size, shape, element distribution and orientation relationship with the α-Al matrix. It was found that (i) most primary Al3(Sc,Zr) phases have a cubic three-dimensional morphology, with a size of about 6–10 μm, (ii) most primary Al3(Sc,Zr) phases are located within the α-Al matrix, and exhibit a cube to cube orientation relationship with the α-Al matrix, and (iii) a layer by layer growth was observed within primary Al3(Sc,Zr) phases. Al, Cu, Si and Fe are enriched in the α-Al matrix between the layers of cellular eutectic Al3(Sc,Zr) phase, while Sc, Ti and Zr are enriched in small Al3(Sc,Zr) phases. A peritectic reaction and subsequent eutectic reaction between Al3Sc and Al was proposed to interpret the observed layer by layer growth. This paper demonstrates that the presence of impurities (Fe, Si, Cu, Ti) in the diffusion field surrounding the growing Al3(Sc,Zr) particle enhances the heterogeneous nucleation of Al3(Sc,Zr) phases. - Highlights: • Most fine cubic primary Al3(Sc,Zr) phases were observed within the α-Al matrix. • A layer by layer growth within primary Al3(Sc,Zr) phase was observed. • A peritectic and subsequent eutectic reaction between Al3Sc and Al was proposed. • Impurities in diffusion fields enhance heterogeneous nucleation of Al3(Sc,Zr)

  11. A Relationship Strategy Perspective on Relationship Portfolios

    DEFF Research Database (Denmark)

    Ritter, Thomas; Andersen, Henrik

    2014-01-01

    The paper develops a three-dimensional portfolio model for business relationships which distinguishes among six different categories. Based on assessments of customer profitability, customer commitment, and growth potential, the positioning of a given customer relationship in the portfolio allows...... managers to determine appropriate customer relationship strategies and appropriate performance indicators. Results from applying the portfolio model are reported and managerial implications and future research are discussed....

  12. KWIN nu ook als app

    NARCIS (Netherlands)

    Rotgers, G.; Vermeij, I.

    2014-01-01

    KWIN, Kwantitatieve Informatie Veehouderij, verscheen de afgelopen 25 jaar als lijvig handboek, zowel op papier als digitaal. Dit najaar is daar een serie apps bij gekomen, waarmee adviseurs en veehouders zelf saldo- en kostprijsberekeningen kunnen maken. De apps zijn beschikbaar voor de pluimvee-,

  13. Philosophieren als Unterrichtsprinzip im Mathematikunterricht

    Science.gov (United States)

    Meerwaldt, Diana

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

  14. Fedora: An Architecture for Complex Objects and their Relationships

    OpenAIRE

    Lagoze, Carl; Payette, Sandy; Shin, Edwin; Wilper, Chris

    2005-01-01

    The Fedora architecture is an extensible framework for the storage, management, and dissemination of complex objects and the relationships among them. Fedora accommodates the aggregation of local and distributed content into digital objects and the association of services with objects. This al-lows an object to have several accessible representations, some of them dy-namically produced. The architecture includes a generic RDF-based relation-ship model that represents relationships among objec...

  15. Personality and Sibling Relationships.

    Science.gov (United States)

    Furman, Wyndol; Lanthier, Richard P.

    1996-01-01

    This study examined the role personality variables play in sibling relationships. It proposed that the characteristics of sibling relationships are influenced by: family constellation variables such as birth order, gender, and age spacing; parent-child relationships including quality of relationship and parent management of siblings; and the…

  16. Banka Çalışanlarında Tükenmişlik ve Beş Büyük Kişilik Özellikleri Arasındaki İlişki: Bir Alan Araştırması(A Relationship Between Burnout and Big-Five Personality Traits of Banking Employees: A Case Study)

    OpenAIRE

    Süren, Seray; Örücü, Edip; İZCİ, Çağrı

    2016-01-01

    Çalışmada bireylerin kişilik özellikleri ve tükenmişlik düzeyleri tespit edilerek kişilik özelliklerinin tükenmişlik üzerindeki etkisi incelenmiştir. Çalışmanın söz konusu amacı doğrultusunda Eylül 2014-Mart 2015 tarihleri arasında Güney Marmara Bölgesinde bulunan Bursa, Çanakkale ve Balıkesir illerindeki 412 banka çalışanından toplanan veriler kullanılmıştır. Bu çerçevede yapılan çalışma sonucunda tükenmişlik değişkeni istatistiksel olarak anlamlı düzeyde beş büyük kişilik boy...

  17. Development of Adolescent Relationships

    OpenAIRE

    Goede, I.H.A. de

    2009-01-01

    This dissertation on “Development of Adolescent Relationships” addresses relationships with parents, friends, and romantic partners in adolescence from a developmental perspective. By studying both parent-adolescent relationships and peer relationships at the same time, as well as interrelations between these types of relationships, this dissertation provides more information on the processes taking place in relationships during adolescence. Findings indicate that parent-adolescent relationsh...

  18. El miedo al rey

    Directory of Open Access Journals (Sweden)

    François FORONDA

    2007-01-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

  20. Study of δ-hydrides in Ti-2Al-2.5Zr and Ti-4Al-2V alloys

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The α alloy Ti-2Al-2.5Zr and near α alloy Ti-4Al-2V were hydrogenated to various levels. The morphology,orientation relation (OR), and habit plane of the hydrides were studied by means of transmission electron microscopy (TEM). It was found that in the two alloys most of the precipitates are δ-hydrides which have fcc structure with the lattice parameter a = 0.44 nm. Two basic orientation relationships and habit planes of the precipitates are determined. Twin structure was observed in both alloys.

  1. Crystallography of Zr poisoning of Al-Ti-B grain refinement using edge-to-edge matching model

    Institute of Scientific and Technical Information of China (English)

    黄元春; 肖政兵; 刘宇

    2013-01-01

    The mechanism of zirconium poisoning on the grain-refining efficiency of an Al-Ti-B based grain refiner was studied. The experiment was conducted by melting Al-5Ti-1B and Al-3Zr master alloys together. The edge-to-edge matching model was used to investigate and compare the orientation relationships between the binary intermetallic compounds present in the Al-Ti-B-Zr system. The results show that the poisoning effect probably results from the combination of Al3 Zr with Al3 Ti and the decreased amount of Ti solute, for Al3 Ti particles have good crystallographic relationships with Al3 Zr. Totally six orientation relationships may present between them, while they play vital roles in grain refinement. TiB2 particles appear to remain unchanged because of a bit large misfit. Only one orientation relationship may present between them to prevent Al3 Zr phase from forming on the surface of TiB2, though TiB2 is agglomerated. The theoretical calculation agrees well with the experimental results. The edge-to-edge matching model is proved to be a useful tool for discovering the orientation relationships between phases.

  2. Consoer et al PFOS dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — This ScienceHub entry was developed for the published paper: Consoer et al., 2016, Toxicokinetics of perfluorooctane sulfonate in rainow trout (Oncorhynchus...

  3. EKSKURSO AL CANGYAN-MONTO

    Institute of Scientific and Technical Information of China (English)

    Verkita; de; Li; Shijun

    1999-01-01

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

  4. DESAFÍOS AL ORDEN

    Directory of Open Access Journals (Sweden)

    Evangelina De los Rios

    2012-03-01

    Full Text Available Fradkin, Raúl y Gelman, Jorge (Compiladores, Desafíos al Orden. Política y sociedades rurales durante la Revolución de Independencia, Prohistoria ediciones, Rosario, 2008, 157 pp.

  5. Seltzer_et_al_2016

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset supports the modeling study of Seltzer et al. (2016) published in Atmospheric Environment. In this study, techniques typically used for future air...

  6. Information als Gegenstand von Informationskompetenz

    OpenAIRE

    Ingold, Marianne

    2011-01-01

    Der Informationsbegriff als zentraler Gegenstand von Informationskompetenz wird in der bibliothekarischen Diskussion in der Regel nicht explizit thematisiert, sondern lässt sich aus Fachliteratur und Bibliothekspraxis nur implizit erschließen. Eine theoretische Beschäftigung mit dem Informationsbegriff ist jedoch unabdingbar, soll das Konzept "Informationskompetenz" auch außerhalb des bibliothekarischen Kontextes verständlich und nutzbar gemacht werden. Im vorliegenden Text, der sich als Beit...

  7. {gamma}-Al{sub 2}O{sub 3} thin film formation via oxidation of {beta}-NiAl(1 1 0)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhongfan, E-mail: zhangzhongfan@gmail.com [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Li Long; Yang, Judith C. [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2011-09-15

    {beta}-NiAl(1 1 0) was oxidized in air for 1-2 h in the temperature range of 650-950 deg. C. The structure and morphology of the oxide films were characterized using a cross-sectional transmission electron microscopy (TEM) method. Only a thin film of aluminum oxide, {gamma}-Al{sub 2}O{sub 3}, was formed. The epitaxial relationship between NiAl and {gamma}-Al{sub 2}O{sub 3} as well as the surface roughness depends on the oxidation temperature. The Nishiyama-Wassermann (NW) orientation relation (OR) between {beta}-NiAl and {gamma}-Al{sub 2}O{sub 3} was noted at an oxidation temperature of 850 deg. C while the Kurdjumov-Sachs (KS) OR was observed at 650 deg. C. The changes in the epitaxial relationship between the {gamma}-Al{sub 2}O{sub 3} film and the NiAl substrate were caused by lattice mismatch-induced strain energy during oxide growth. It was also noted that short time oxidation at T = 750 deg. C created {gamma}' phase precipitates between the NiAl substrate and the {gamma}-Al{sub 2}O{sub 3} film, while oxidation at the higher temperature of 950 deg. C resulted in textured polycrystalline {gamma}-Al{sub 2}O{sub 3} films. The smoothest single crystal epitaxial {gamma}-Al{sub 2}O{sub 3} film formed at an oxidation temperature of 850 deg. C in air.

  8. Loss of ALS2/Alsin exacerbates motor dysfunction in a SOD1-expressing mouse ALS model by disturbing endolysosomal trafficking.

    Directory of Open Access Journals (Sweden)

    Shinji Hadano

    Full Text Available BACKGROUND: ALS2/alsin is a guanine nucleotide exchange factor for the small GTPase Rab5 and involved in macropinocytosis-associated endosome fusion and trafficking, and neurite outgrowth. ALS2 deficiency accounts for a number of juvenile recessive motor neuron diseases (MNDs. Recently, it has been shown that ALS2 plays a role in neuroprotection against MND-associated pathological insults, such as toxicity induced by mutant Cu/Zn superoxide dismutase (SOD1. However, molecular mechanisms underlying the relationship between ALS2-associated cellular function and its neuroprotective role remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: To address this issue, we investigated the molecular and pathological basis for the phenotypic modification of mutant SOD1-expressing mice by ALS2 loss. Genetic ablation of Als2 in SOD1(H46R, but not SOD1(G93A, transgenic mice aggravated the mutant SOD1-associated disease symptoms such as body weight loss and motor dysfunction, leading to the earlier death. Light and electron microscopic examinations revealed the presence of degenerating and/or swollen spinal axons accumulating granular aggregates and autophagosome-like vesicles in early- and even pre-symptomatic SOD1(H46R mice. Further, enhanced accumulation of insoluble high molecular weight SOD1, poly-ubiquitinated proteins, and macroautophagy-associated proteins such as polyubiquitin-binding protein p62/SQSTM1 and a lipidated form of light chain 3 (LC3-II, emerged in ALS2-deficient SOD1(H46R mice. Intriguingly, ALS2 was colocalized with LC3 and p62, and partly with SOD1 on autophagosome/endosome hybrid compartments, and loss of ALS2 significantly lowered the lysosome-dependent clearance of LC3 and p62 in cultured cells. CONCLUSIONS/SIGNIFICANCE: Based on these observations, although molecular basis for the distinctive susceptibilities to ALS2 loss in different mutant SOD1-expressing ALS models is still elusive, disturbance of the endolysosomal system by ALS2 loss

  9. Abrasive wear characteristics and mechanisms of Al2O3/PA1010 composite coatings

    Institute of Scientific and Technical Information of China (English)

    JIA Xian; LING Xiaomei

    2004-01-01

    The abrasive wear characteristics of Al2O3/PA1010 composite coatings on the surface of quenched and low-temperature temper steel 45 were tested on the mmplate abrasive wear testing machine and the same uncoated steel 45 was used as a reference material. Experimental results showed that the abrasive wear resistance of Al2O3//PAl010 composite coatings has a good linear relationship with the volume fraction of Al2O3 particles in Al2O3/PAl010 composite coatings, and the linear correlative coefficient is 0.979. Under the experimental conditions, the size of Al2O3 particles (40.5-161.0 μm) has little influence on the abrasive wear resistance of Al2O3/PA l010 composite coatings. By treating the surface of Al2O3 particles with a suitable bonding agent, the distribution of Al2O3 particles in matrix PAl010 is more homogeneous and the bonding state between Al2O3 particles and matrix PAl010 is better. Therefore, the ml2O3 particles in Al2O3/PA1010 composite coatings make the Al2O3/PAl010 composite coatings have better abrasive wear resistance than PA1010 coatings. The wear resistance of Al2O3/PA 1010 composite coatings is about 45% compared with that of steel 45.

  10. Fading Customer Relationships

    OpenAIRE

    Åkerlund, Helena

    2004-01-01

    This dissertation is based on the assumption that fading customer relationships are important phenomena to understand in order for companies to prevent a future relationship termination, manage a desired relationship termination, or manage the situation where the relationship strength temporarily or permanently has weakened but where the customer still stays with the same service provider. It is assumed that fading could take different forms and develop through a range of different proces...

  11. Equivalent conductivity and its activation energy of NaF-AlF3 melts

    Institute of Scientific and Technical Information of China (English)

    HU Xian-wei; WANG Zhao-wen; GAO Bing-liang; SHI Zhong-ning; KAN Hong-min; LUO Xu-dong; TAO Wen-ju

    2009-01-01

    Electrical conductivity of NaF-AlF3 melts was measured by continuously varying cell constant(CVCC) technique. Relationships between equivalent conductivity at 990-1 030 ℃ and temperature and composition, and relationship between equivalent conductivity activation energy and composition of the melts were then studied on the basis of two-step decomposition mechanism of AlF63-. According to the changes of molar fractions of different anions in NaF-AlF3 melts, courses of dependence of equivalent conductivity and its activation energy on composition were analyzed. The results show that the influence of temperature on equivalent conductivity of the melts is small in the researched temperature range, and equivalent conductivity increases with increasing the molar fraction of AlF3; there is a minimum point in the activation energy-composition curve when molar fraction of AlF3 is 0.29.

  12. A study on the orientation inheritance in laminated NiAl produced by in situ reaction annealing.

    Science.gov (United States)

    Du, Yan; Fan, Guohua; Geng, Lin

    2016-04-01

    In order to promote the performance of B2 NiAl by texture control of orientation during in situ processing, phase transformation in laminated NiAl with bimodal grain size distribution manufactured by reaction annealing of Ni and Al foils has been studied. It turned out that there existed a Kurdjumov-Sachs orientation relationship (K-S OR) between parent Ni and product NiAl by crystallography analysis according to the electron backscatter diffraction (EBSD) results. The parent Ni did not transform to the product NiAl directly but via the formation of Ni3Al firstly according to the transmission electron microscope (TEM) observation of the interface. This led to a new K-S OR between Ni3Al and NiAl with a small atomic misfit, which made less residual stress generated through the formation of Ni3Al than directly from the parent Ni. PMID:26867210

  13. Strain sensing with sub-micron sized Al-AlOx-Al tunnel junctions

    OpenAIRE

    Koppinen, P. J.; Lievonen, J. T.; Ahlskog, M.; Maasilta, I. J.

    2009-01-01

    We demonstrate a local strain sensing method for nanostructures based on metallic Al tunnel junctions with AlOx barriers. The junctions were fabricated on top of a thin silicon nitride membrane, which was actuated with an AFM tip attached to a stiff cantilever. A large relative change in the tunneling resistance in response to the applied strain (gauge factor) was observed, up to a value 37. This facilitates local static strain variation measurements down to ~10^{-7}.

  14. The influence of the sustainability agenda on buyer-supplier relationships

    DEFF Research Database (Denmark)

    Jørsfeldt, Liliyana Makarowa; Wæhrens, Brian Vejrum

    2013-01-01

    The positive effect of supplier-buyer relationships on supply chain performance has al-ready been supported by previous studies. Yet, little empirical research has explored how the sustainability agenda influences these relationships. Thus, this study investi-gates how supplier-buyer relationships...... their cross-functional team-working, increase data sharing and to penetrate deeper into operational processes....

  15. En el oscuro corazón de la etnografía. Ética y desigualdades en las relaciones íntimas al interior del campo Into the dark heart of ethnography: The lived ethics and inequality of intimate field relationships

    OpenAIRE

    Katherine Irwin

    2008-01-01

    En este artículo, reflejo algunos de los debates con respecto a la intimidad y explotación examinando mi relación con mi informante clave. Recorro la manera en que, a pesar de mis intentos de seguir las guías éticas existentes, reforcé varias y grandes desigualdades en mi postura íntima. Sostengo que nuestras discusiones sobre métodos íntimos y la inmersión en el campo han fallado al observar adecuadamente cómo reforzamos o resistimos la estructura en nuestros esfue...

  16. Al clamor de les vuvuzeles

    Directory of Open Access Journals (Sweden)

    Javier Olivera Betrán

    2010-09-01

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

  17. DIFERENCIAS EN ESTRÉS PERCIBIDO, SALUD MENTAL Y FÍSICA DE ACUERDO AL TIPO DE RELACIÓN HUMANO-PERRO / DIFFERENCES IN PERCEIVED STRESS, MENTAL HEALTH, AND PHYSICAL HEALTH ACCORDING TO TYPES OF HUMAN-PET DOG RELATIONSHIPS

    OpenAIRE

    MÓNICA TERESA GONZÁLEZ RAMÍREZ; RENÉ LANDERO HERNÁNDEZ

    2011-01-01

    This study was carried out in order to assess whether the levelsof perceived stress and health differed depending on typesof human-pet dog relationships, and to evaluate the correlationbetween perceived stress and health and the frequencywith which activities are carried out with the dogs. Self-reportquestionnaires were filled out by 247 volunteers owning atleast one dog. The results show lower levels of perceived stressand higher levels of mental health in those individuals whoconsider the d...

  18. Into the dark heart of ethnography: The lived ethics and inequality of intimate field relationships En el oscuro corazón de la etnografía. Ética y desigualdades en las relaciones íntimas al interior del campo

    OpenAIRE

    Katherine Irwin

    2008-01-01

     

    In this paper, I reflect on some of the debates regarding intimacy and exploitation by examining my relationship with my key informant. I trace the way that, despite my attempts to follow the existing ethical guides, I reinforced several larger inequalities in my intimate stance. I argue that our discussions of intimate methods and immersion in the field have failed to accurately note how we reinforce or resist structu...

  19. Çalışanların Kararlara Katılımı ve Örgütsel Politika Algısı İlişkisi (Relationship Between Employee’s Participative Decision Making And Perception Of Organizational Politics)

    OpenAIRE

    Yunus Bıyık; Pelin Erden; Enver Aydoğan

    2016-01-01

    This study aims to reveal the relationship between employee's participative decision making and perception of organizational politics. In a total of 11 municipalities all located in Tokat province and districts, 178 staff working in the permanent civil servants participated to research. A result of research it was found a negative weak correlation among the perception of organizational politics and participative decision making variables. Findings were obtained that the level o...

  20. Maintaining Relationship Based Procurement

    Directory of Open Access Journals (Sweden)

    Peter Davis

    2012-11-01

    Full Text Available Alliance and relationship projects are increasingin number and represent a large pool of work. Tobe successful relationship style contracts dependon soft-dollar factors, particularly the participants'ability to work together within an agreedframework, generally they are not based on lowbid tendering. Participants should be prepared todo business in an open environment based ontrust and mutually agreed governance. Theresearch evaluates relationship maintenance inthe implementation phase of constructionalliances - a particular derivative of relationshipstyle contracts. To determine the factors thatcontribute to relationship maintenance forty-nineexperienced Australian alliance projectmanagers were interviewed. The main findingswere; the development of relationships early inthe project form building blocks of success fromwhich relationships are maintained and projectvalue added; quality facilitation plays animportant part in relationship maintenance and ahybrid organisation created as a result of alliancedevelopment overcomes destructiveorganisational boundaries. Relationshipmaintenance is integral to alliance project controland failure to formalise it and pay attention toprocess and past outcomes will undermine analliance project's potential for success.

  1. Ideals in intimate relationships.

    Science.gov (United States)

    Fletcher, G J; Simpson, J A; Thomas, G; Giles, L

    1999-01-01

    This research examined lay relationship and partner ideals in romantic relationships from both a social-cognitive and an evolutionary perspective. Studies 1 and 2 revealed that the qualities of an ideal partner were represented by 3 factors (partner warmth-trustworthiness, vitality-attractiveness, and status-resources), whereas the qualities of an ideal relationship were represented by 2 factors (relationship intimacy-loyalty and passion). A confirmatory factor analysis in Study 3 replicated these factor structures but found considerable overlap across the partner and relationship dimensions. Studies 4 and 5 produced convergent and discriminant validity evidence for all 5 factors. Study 6 indicated that the higher the consistency between the ideals and related assessments of the current partner and relationship, the more positively the current relationship was evaluated. PMID:9972554

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

    International Nuclear Information System (INIS)

    Because flake-like TiAl3 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 TiAl3 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

  3. Conjuntivitis alérgica

    Directory of Open Access Journals (Sweden)

    Alejandro Tello Hernández

    2008-07-01

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

  4. Electrowinning Al from Al2S3 in Molten Salt

    NARCIS (Netherlands)

    Xiao, Y.; Van der Plas, D.W.; Bohte, J.; Lans, S.C.; Van Sandwijk, A.; Reuter, M.A.

    2007-01-01

    In order to investigate an alternative process for the production of primary aluminum via a sulfide intermediate, the electrochemical behavior of Al2S3 in molten salt has been studied on a laboratory scale. The effects of electrolyte composition, temperature, and cell design on the cell performance

  5. ALS:A SAIRASTAVAN TOIMINTATERAPIA

    OpenAIRE

    Vuorinen, Johanna

    2013-01-01

    Amyotrofinen lateraali skleroosi on harvinainen, etenevä sairaus. Sairaus surkastuttaa edetessään potilaan tahdonalaisen lihaksiston. Sairauden oireet näkyvät yleensä ensin raajoissa, mutta myös nielun lihaksista alkava bulbaarinen taudinmuoto on mahdollinen. ALS voi myös aiheuttaa frontotemporaalista dementiaa. Sairaus etenee yksilöllisesti, mutta sen kesto on yleensä noin 3-5 vuotta. Keski-Suomen keskussairaalassa ALS:n sairastuneen kuntoutukseen osallistuu moniammatillinen työryhmä, j...

  6. Al-Qaeda Since 911

    OpenAIRE

    Brahimi, Alia

    2012-01-01

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

  7. Involvement and Loyalty in Recreation Swimming in Greece: Investigating Relationships

    OpenAIRE

    Evangelia Kontogianni; Charilaos Kouthouris; Achilleas Barlas; Vasileiοs Voutselas

    2011-01-01

    Present study tested the validity of involvement scale (Kyle et al., 2004), examined differences according demographic characteristics and investigated possible relationships between involvement and attitudinal loyalty in context of recreational swimming. Three hundred and forty nine participants (61.9% females) from a major swimming sport center in northern Greece, completed the three dimensional involvement model of Kyle’s et al (2004), and Armitage & Conner’s (1999) attitudinal loyalty’s i...

  8. A new method to evaluate the hydraulic activity of Al-Si materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Slag,fly ash,gangue and 500℃ calcined gangue are analyzed by using identical coupled plasma optical emission spectroscopy (ICP),X-ray photoelectron spec-troscopy (XPS),infrared spectroscopy (IR) and magnetic angle spinning nuclear magnetic resonance (MAS NMR). Research results show that there is a negative linear relationship between the Si 2p and Al 2p binding energies of Al-Si materials and the compressive strength of aluminosilicate based cementitious materials prepared with these Al-Si materials,i.e. the lower the binding energies,the higher the compressive strength. Indeed,the Si 2p and Al 2p binding energies of Al-Si materials can be used to indicate their hydraulic activity. The binding energies of the four examined materials increase in the order of slag,fly ash,500℃ calcined gangue and untreated gangue. Moreover,the binding energies of Si 2p,Al 2p and O 1s of every Al-Si material have excellent correlation. By using the Al 2p binding energy and 27Al MAS NMR spectra,the coordination number of aluminum in slag is determined to be four,while that in gangue,is six. Based on the aforementioned discoveries,this paper presents a new effective method to evaluate the hydraulic activity of Al-Si materials by using the surface binding energies of silicon and alu-minum of Al-Si materials.

  9. Dehydrogenation process of AlH{sub 3} observed by TEM

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Yuki, E-mail: y-nakagawa@eng.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, N-13, W-8, Sapporo 060-8278 (Japan); Isobe, Shigehito [Graduate School of Engineering, Hokkaido University, N-13, W-8, Sapporo 060-8278 (Japan); Creative Research Institution, Hokkaido University, N-21, W-10, Sapporo 001-0021 (Japan); Wang, Yongming; Hashimoto, Naoyuki; Ohnuki, Somei [Graduate School of Engineering, Hokkaido University, N-13, W-8, Sapporo 060-8278 (Japan); Zeng, Liang; Liu, Shusheng; Ichikawa, Takayuki; Kojima, Yoshitsugu [Institute for Advanced Materials Research, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan)

    2013-12-15

    Highlights: ► The initial shape of α-AlH{sub 3} particle is cubic and that of γ-AlH{sub 3} is rod-shaped. ► Dehydrogenation kinetics does not depend on Al{sub 2}O{sub 3} thickness in the 4.6–7.8 nm range. ► Milling effect on dehydrogenation kinetics will be larger than doping effect. -- Abstract: Dehydrogenation processes of α- and γ-AlH{sub 3} were investigated by in situ transmission electron microscopy observations. The relationship between Al{sub 2}O{sub 3} thickness and dehydrogenation kinetics was also clarified. The initial shape of α-AlH{sub 3} particle was cubic and that of γ-AlH{sub 3} particle was rod-shaped. The process of γ-AlH{sub 3} was quite similar with α-AlH{sub 3}. The precipitation and growth of Al was observed in both processes. The dehydrogenation kinetics did not depend on Al{sub 2}O{sub 3} thickness. It was found that milling effect on the dehydrogenation kinetics was larger than doping effect. The dehydrogenation process was discussed in terms of both microscopic and kinetic studies.

  10. The Role of Trust on the Relationship Between Organizational Engagement and Corporate Reputation(Çalışanların Örgüte Cezbolması ve Kurumların İtibarı İlişkisinde Güvenin Rolü

    Directory of Open Access Journals (Sweden)

    Emel ESEN

    2012-01-01

    Full Text Available The purpose of this study is to examine the role of organizational trust between corporate reputation practices and organizational engagement in airline sector. In the first section, results of the relationship between corporate reputation practices, organizational trust and organizational engagement are examined. In the following section, data was gathered from 343 participants. According to the results of the study, corporate reputation practices and organizational trust have effect on organizational engagement but organizational trust hasn’t had any intervening role between these variables.

  11. Andalusian astronomy: al-Zij al-Muqtabis of Ibn al-Kammâd.

    Science.gov (United States)

    Chabás, J.; Goldstein, B. R.

    1994-12-01

    In the twelfth century the Arabic astronomer Ibn al-Kammâd, living in Islamic Spain, composed three sets of astronomical tables, called "zijes". The zijes were largely based on the work of predecessors, going back to Ptolemy on the one hand, and Hindu astronomers on the other. None of his zijes survived in the original Arabic, but a Latin manuscript contains a translation of an apparently complete zij, the "al-Zij al-Muqtabis". This paper examines the body of astronomical knowledge contained in this zij. Specifically, it is shown that one can gain valuable information on the solar theory of the Islamic astronomers from this translation. Furthermore, the theory of lunar and solar eclipses in the work is analyzed, and tables of mean planetary and solar motions are discussed. In addition, tables for the motion of the vernal equinox, star tables, and several topics of Islamic spherical astronomy are examined.

  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. Residual stresses in continuous graphite fiber Al metal matrix composites

    Science.gov (United States)

    Park, Hun Sub; Zong, Gui Sheng; Marcus, Harris L.

    1988-01-01

    The residual stresses in graphite fiber reinforced aluminum (Gr/Al) composites with various thermal histories are measured using X-ray diffraction (XRD) methods. The XRD stress analysis is based on the determination of lattice strains by precise measurements of the interplanar spacings in different directions of the sample. The sample is a plate consisting of two-ply P 100 Gr/Al 6061 precursor wires and Al 6061 overlayers. Prior to XRD measurement, the 6061 overlayers are electrochemically removed. In order to calibrate the relationship between stress magnitude and lattice spacing shift, samples of Al 6061 are loaded at varying stress levels in a three-point bend fixture, while the stresses are simultaneously determined by XRD and surface-attached strain gages. The stresses determined by XRD closely match those determined by the strain gages. Using these calibrations, the longitudinal residual stresses of P 100 Gr/Al 6061 composites are measured for various heat treatments, and the results are presented.

  14. Phase diagram of the Al-Er-Mo ternary system at 873 K

    Science.gov (United States)

    Pan, Yanfang; Yang, Wenchao; Tang, Chenghuang; Lan, Yanni; Zhan, Yong Zhong

    2015-11-01

    The phase relationship in the Al-Er-Mo ternary system at 873 K has been investigated based on the equilibrated method mainly by means of X-ray powder diffraction and scanning electron microscopy. The existence of 10 binary compounds and two ternary compounds has been confirmed. The results present that the isothermal section at 873 K is governed by 15 single-phase regions, 29 two-phase regions and 15 three-phase regions. By using the phase-disappearing method, Al8Mo3 has a narrow homogeneity range (from 72 to 73 at% Al), while the homogeneity range of AlMo3 is from 21% to 28.5% at% Al. Also, the maximum solubility of Al in Mo is about 16 at%.

  15. Dynamic Modeling of ALS Systems

    Science.gov (United States)

    Jones, Harry

    2002-01-01

    The purpose of dynamic modeling and simulation of Advanced Life Support (ALS) systems is to help design them. Static steady state systems analysis provides basic information and is necessary to guide dynamic modeling, but static analysis is not sufficient to design and compare systems. ALS systems must respond to external input variations and internal off-nominal behavior. Buffer sizing, resupply scheduling, failure response, and control system design are aspects of dynamic system design. We develop two dynamic mass flow models and use them in simulations to evaluate systems issues, optimize designs, and make system design trades. One model is of nitrogen leakage in the space station, the other is of a waste processor failure in a regenerative life support system. Most systems analyses are concerned with optimizing the cost/benefit of a system at its nominal steady-state operating point. ALS analysis must go beyond the static steady state to include dynamic system design. All life support systems exhibit behavior that varies over time. ALS systems must respond to equipment operating cycles, repair schedules, and occasional off-nominal behavior or malfunctions. Biological components, such as bioreactors, composters, and food plant growth chambers, usually have operating cycles or other complex time behavior. Buffer sizes, material stocks, and resupply rates determine dynamic system behavior and directly affect system mass and cost. Dynamic simulation is needed to avoid the extremes of costly over-design of buffers and material reserves or system failure due to insufficient buffers and lack of stored material.

  16. Un controesempio al Modus Ponens

    Directory of Open Access Journals (Sweden)

    Vann McGee

    2011-11-01

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

  17. Türkiye’de eğitimsel eşitsizlik ve toplumsal tabakalaşma ilişkisine dair ampirik bir çalışma [The relationship between educational inequality and social stratification in Turkey: An empirical study

    Directory of Open Access Journals (Sweden)

    Yalın KILIÇ

    2014-10-01

    Full Text Available Bu çalışmada, Türkiye’deki eğitimsel eşitsizliklerin toplumsal tabakalar açısından çözümlenmesi amaçlanmıştır. Araştırma TÜİK tarafından uygulanan 2006 yılı Hane Halkı Bütçe Anketi verilerine dayalı olarak planlanmıştır. Hane Halkı Bütçe Anketleri, hanelerin sosyo-ekonomik yapıları, yaşam düzeyleri, tüketim kalıpları hakkında bilgi veren ve toplumun gereksinimlerinin belirlenmesi, kullanılabilir gelirin haneler ya da bireyler arasında ne şekilde dağıldığının bilinmesi ve uygulanan sosyo-ekonomik politikaların geçerliğinin test edilmesi amacıyla kullanılan en önemli kaynaklardan biridir. Dolayısıyla bu çalışmada hane halkı bütçe anketinin verileri toplumsal tabakaların oluşturulmasında temel veri kaynağını oluşturmuştur. Çalışmada, yetişkin nüfusun eğitim düzeyinin cinsiyetle ve elde edilen gelirle ve eğitim çağındaki çocukların eğitim kademeleri itibariyle okullaşma oranlarının cinsiyetle ve hanedeki kişi başı düşen ortalama gelirle ilişkileri toplumsal tabakalar açısından incelenmektir. Bu hedef doğrultusunda öncelikle TÜİK tarafından uygulanan 2006 yılı Hane Halkı Bütçe Anketi verileri işlenmiş ve analiz edilmiştir. Çalışmada verilerin özelliklerine ve kurulan hipotezlere göre; Kay-kare, korelasyon ve varyans analizi yapılmıştır. Yapılan çözümlemeler sonucunda toplumsal tabakaların eğitimsel eşitsizliklerin önemli bir açıklayıcısı olduğu belirlenmiştir.

  18. Customer relationship marketing

    OpenAIRE

    Sæter, Jan Øyvind

    2006-01-01

    Customer relationship marketing has become an interesting choice of strategy for companies in today’s competitive markets. Different positioning strategies like price and product quality are easy to imitate, eluding the importance of sustainable competitive advantage. The customers need to be attracted and bonded towards the store through relationships. The paper discusses several factors affecting relationship marketing and the advantages with this strategy. Through the the...

  19. Customer Energy in Relationships

    OpenAIRE

    Heinonen, Kristina; Mickelsson, Jakob; Strandvik, Tore

    2010-01-01

    All companies have a portfolio of customer relationships. From a managerial standpoint the value of these customer relationships is a key issue. The aim of the paper is to introduce a conceptual framework for customers’ energy towards a service provider. Customer energy is defined as the cognitive, affective and behavioural effort a customer puts into the purchase of an offering. It is based on two dimensions: life theme involvement and relationship commitment. Data from a survey study ...

  20. Customer Energy in Relationships

    OpenAIRE

    Heinonen, Kristina; Strandvik, Tore

    2010-01-01

    All companies have a portfolio of customer relationships. From a managerial standpoint the value of these customer relationships is a key issue. The aim of the paper is to introduce a conceptual framework for customers’ energy towards a service provider. Customer energy is defined as the cognitive, affective and behavioural effort a customer puts into the purchase of an offering. It is based on two dimensions: life theme involvement and relationship commitment. Data from a survey study of 425...

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

    Directory of Open Access Journals (Sweden)

    Jia-Ning Zhuang

    2011-12-01

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

  3. Personalidad y tolerancia al dolor

    Directory of Open Access Journals (Sweden)

    JESÚS M.ª CARRILLO

    2005-01-01

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

  4. Governing IT outsourcing relationships

    CERN Document Server

    Kuhlmann, Daniel

    2012-01-01

    Hauptbeschreibung The dynamics of the relationship between service recipient and service provider in IS outsourcing relationships recently gained increased attention as relationships are believed to have a considerable influence on IS outsourcing success. This study adds to this growing field of interest by developing an IS outsourcing relationship framework in the form of a process model. Three rather disjointed areas of research, namely contractual governance, relational norms, and control, have been set in a common context by interrelating them as the three main governance modes

  5. 76 FR 38700 - United States, et al.

    Science.gov (United States)

    2011-07-01

    ... Antitrust Division United States, et al. v. American Express Company, et al.; Public Comments and Response...), the United States hereby publishes below its Response to public comments received on the proposed Final Judgment in United States, et al. v. American Express Company, et al., Civil Action No....

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

    Science.gov (United States)

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

    2015-09-21

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

  7. Al/Au/n-Si/Al surface barrier detector

    International Nuclear Information System (INIS)

    Charged-particle detectors are required to be operated sometimes in ambient light for applications like alpha counting and range finding. Detectors like Al/p-Si surface barrier with aluminium on the front side are found quite suitable. Gold/n-Si surface barrier detectors are not usable because of their excessive background photo current. These detectors, we fabricate for use in nuclear experiments, were given an aluminium coating on their gold side for use in room light. The Au/n-Si/Al surface barrier diodes were characterized for their electrical properties and performance as alpha detectors. Detectors showing good energy resolution (∼ 50 KeV) were selected and provided with another thin reflecting coat of aluminium on their front sides

  8. Stokes-Einstein relation and excess entropy in Al-rich Al-Cu melts

    Science.gov (United States)

    Pasturel, A.; Jakse, N.

    2016-07-01

    We investigate the conditions for the validity of the Stokes-Einstein relation that connects diffusivity to viscosity in melts using entropy-scaling relationships developed by Rosenfeld. Employing ab initio molecular dynamics simulations to determine transport and structural properties of liquid Al1-xCux alloys (with composition x ≤ 0.4), we first show that reduced self-diffusion coefficients and viscosities, according to Rosenfeld's formulation, scale with the two-body approximation of the excess entropy except the reduced viscosity for x = 0.4. Then, we use our findings to evidence that the Stokes-Einstein relation using effective atomic radii is not valid in these alloys while its validity can be related to the temperature dependence of the partial pair-excess entropies of both components. Finally, we derive a relation between the ratio of the self-diffusivities of the components and the ratio of their pair excess entropies.

  9. In situ fabrication and microstructure of Al2O3 particles reinforced aluminum matrix composites

    International Nuclear Information System (INIS)

    Al2O3p/Al composites were prepared by direct melt reaction process. The thermodynamics of in situ chemical reactions between molten aluminum and CeO2 powder was studied. The XRD results show that the components of the as-prepared composites consist of Al2O3 and Al phases. For the as-cast composite specimens, SEM, EDX, TEM and SAD were used to analyze the reinforcement phases and interface characters of composites. The results show that the in situ generated Al2O3 particles, whose sizes are 100-200 nm, have various irregular shapes and disperse uniformly in matrix. TEM observation shows that the interface between particle and matrix is clean. Furthermore, there is no fixed orientation relationship between Al2O3 particles and aluminum matrix. Only [12-bar 10]//[111] orientation parallel relationship with low exponent is found. Therefore, the composites have isotropic properties. Besides characters mentioned above, there are large amount of high density dislocations and the generated extensive fine subgrains around Al2O3 particles. These features are favorable for improving composite performances. As a result, the composites are comprehensively strengthened not only by Al2O3 particles, but also by the high density dislocations and fine subgrains.

  10. The fcc-bcc crystallographic orientation relationship in AlxCoCrFeNi high-entropy alloys

    NARCIS (Netherlands)

    Rao, J. C.; Ocelik, V.; Vainchtein, D.; Tang, Z.; Liaw, P. K.; De Hosson, J. Th. M.

    2016-01-01

    This paper concentrates on the crystallographic-orientation relationship between the various phases in the Al-Co-Cr-Fe-Ni high-entropy alloys. Two types of orientation relationships of bcc phases (some with ordered B2 structures) and fcc matrix were observed in Al0.5CoCrFeNi and Al0.7CoCrFeNi alloys

  11. Number Relationships in Preschool

    Science.gov (United States)

    Jung, Myoungwhon

    2011-01-01

    When a child understands number relationships, he or she comprehends the meaning of numbers by developing multiple, flexible ways of representing them. The importance of developing number relationships in the early years has been highlighted because it helps children build a good foundation for developing a more sophisticated understanding of…

  12. Relationship violence in adolescence.

    Science.gov (United States)

    Lin, Alison J; Raymond, Marissa; Catallozzi, Marina; Ryan, Owen; Rickert, Vaughn I

    2007-12-01

    Previous experience with violence or a deficit in interpersonal skills may lead to violence in adolescent relationships. In this article we focus on various forms of interpersonal violence (bullying, sexual harassment, coercion, and relationship violence) that adolescents may experience and pay special attention to risk factors, help-seeking behaviors, and sequelae.

  13. Relationship Building Blocks

    Science.gov (United States)

    Santabarbara, Todd; Erbe, Ryan; Cooper, Scott

    2009-01-01

    Intimate or romantic relationships for young people today play an integral role in their health and quality of life. Between the ages of 11 and 13 students become more interested in the opposite sex and as a result they begin to develop more intimate relationships. Around this age students are learning to deal with these feelings of attraction and…

  14. DIFERENCIAS EN ESTRÉS PERCIBIDO, SALUD MENTAL Y FÍSICA DE ACUERDO AL TIPO DE RELACIÓN HUMANO-PERRO / DIFFERENCES IN PERCEIVED STRESS, MENTAL HEALTH, AND PHYSICAL HEALTH ACCORDING TO TYPES OF HUMAN-PET DOG RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    MÓNICA TERESA GONZÁLEZ RAMÍREZ

    2011-06-01

    Full Text Available This study was carried out in order to assess whether the levelsof perceived stress and health differed depending on typesof human-pet dog relationships, and to evaluate the correlationbetween perceived stress and health and the frequencywith which activities are carried out with the dogs. Self-reportquestionnaires were filled out by 247 volunteers owning atleast one dog. The results show lower levels of perceived stressand higher levels of mental health in those individuals whoconsider the dog a member of the family. Furthermore, significantcorrelations were found between dog-training activitiesand stress and mental health, between playing with the dogand vitality and mental health, and between walking the dogand vitality. The conclusion was that those individuals whoconsider their dogs as members of the family and carry outmore activities with them have better physical and mentalhealth, as well as lower levels of perceived stress.

  15. A new method to evaluate the hydraulic activity of Al-Si materials

    Institute of Scientific and Technical Information of China (English)

    LI HuaJian; SUN HengHu; TIE XuChu; XIAO XueJun

    2008-01-01

    Slag, fly ash, gangue and 500℃ calcined gangue are analyzed by using identical coupled plasma optical emission spectroscopy (ICP), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and magnetic angle spinning nuclear magnetic resonance (MAS NMR). Research results show that there is a negative linear relationship between the Si 2p and Al 2p binding energies of Al-Si materials and the compressive strength of aluminosilicate based cementitious materials prepared with these Al-Si materials, i.e. the lower the binding energies, the higher the compressive strength. Indeed, the Si 2p and Al 2p binding energies of Al-Si materials can be used to indicate their hydraulic activity. The binding energies of the four examined materials increase in the order of slag, fly ash, 500℃ calcined gangue and untreated gangue. Moreover, the binding energies of Si 2p, Al 2p and O 1s of every Al-Si material have excellent correlation. By using the Al 2p binding energy and 27AI MAS NMR spectra, the coordination number of aluminum in slag is determined to be four, while that in gangue, is six. Based on the aforementioned discoveries, this paper presents a new effective method to evaluate the hydraulic activity of Al-Si materials by using the surface binding energies of silicon and aluminum of Al-Si materials.

  16. Effect of Interface on Mechanical Property of Steel-mushy Al-20Sn Bonding Plate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The ratio of Fe-Al compound at interCace, which could determine the quantity of Fe-Al compound at the interface of steel-mushy Al-20Sn bonding plate, was used to characterize the interfacial structure of steel-mushy Al-20Sn bonding plate quantitatively.The effect of ratio of Fe-Al compound at interface on interfacial shear strength was investigated perfectly.The results show that the relationship between ratio of Fe-Al compound at interface and interfacial shear strength is S = 3.3 + 1.91 t -0.0135 t2 ( where t is ratio of Fe-Al compound at interface and S is interfacial shear strength ).When the ratio of Fe-Al compound at interface is 71% , the largest interfacial shear strength 70.9 MPa is got.This reasonable ratio of Fe-Al compound at interface is a quantitative criterion of interfacial embrittlement.When the ratio of Fe-Al compound at interface is higher than 71%, interfacial embrittlement will occur.

  17. Jealousy and Relationship Closeness

    Directory of Open Access Journals (Sweden)

    Mark Attridge

    2013-02-01

    Full Text Available This study confirmed a hypothesis from the Emotion-in-Relationships conceptual model, which predicts that greater interdependence between relationship partners—or closeness—creates the potential for jealousy. The study also sought to better define the positive side of romantic jealousy in addition to its more negative attributes. College students in premarital relationships (N = 229 completed a questionnaire, including 27 different measures and the Multidimensional Jealousy Scale. Select data were obtained from 122 cases at 3-month follow-up. Each jealousy scale was tested for associations with demographic (age, sex, and race, person (life satisfaction, loneliness, romantic attachment styles, love styles, and romantic beliefs, and relationship (affective, closeness, and social exchange theory constructs. Results clearly distinguished emotional/reactive jealousy as mostly “good” and cognitive/suspicious jealousy as “bad.” Behavioral jealousy was associated with few measures. Implications are discussed for the interdependence model of relationships and the transactional model of jealousy.

  18. Sui controesempi al Modus Ponens

    Directory of Open Access Journals (Sweden)

    Giorgio Sbardolini

    2011-11-01

    Full Text Available In McGee (1985 si presentano tre controesempi al modus ponens (MP, e si argomenta di come esistano restrizioni alla validità di questa regola deduttiva. Nel presente articolo, intendo ridiscutere questi tre controesempi a MP mostrando perché non colgono il bersaglio, e presentare altri casi in cui l'applicazione di MP non sembra efficace.In [McGee, 1985] si presentano 3 controesempi al modus ponens (MP, e si argomenta di come esistano restrizioni alla validità di questa regola deduttiva. Nel presente articolo, intendo ridiscutere questi 3 controesempi a MP mostrando perché non colgono il bersaglio, e presentare altri casi in cui l'applicazione di MP non sembra efficace.

  19. Geographic Trajectories of Al-Qaida and Taliban Terrorist Groups in Pakistan

    Directory of Open Access Journals (Sweden)

    Syed Manzar Abbas Zaidi

    2010-01-01

    Full Text Available Though Western analysts tend to mention al-Qaida and Taliban in Pakistan in the same context, the dynamics of their relationship are far more complex than a cursory examination would reveal. The context of this relationship is best understood within the overarching paradigm of militant activities of post 9/11 Taliban and al-Qaida remnants in Pakistan's tribal areas, where these groups flourish. The military struggle in Afghanistan has significantly influenced the formation of a loosely structured alQaida/Taliban "nexus" that was forged in Pakistan's Federally Administered Tribal Areas (FATA, particularly Waziristan. In order to survive the ongoing North Atlantic Treaty Organization (NATO military operations to flush them out, these groups rapidly devised a symbiotic strategy that characterizes al-Qaida's ability to subsume itself within the ranks of different militant organizations in Pakistan.

  20. Al Margen de las Cooperativas

    Directory of Open Access Journals (Sweden)

    Gutiérrez Estrada Julio

    1941-04-01

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

  1. Vormundschaftsrecht als Grundlage politischer Herrschaft

    Directory of Open Access Journals (Sweden)

    Arne Duncker

    2006-07-01

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

  2. Experimental Studies of Liquid Viscosity in Immiscible Al-In Alloys

    Institute of Scientific and Technical Information of China (English)

    刘广荣; 边秀房; 孙民华

    2003-01-01

    The liquid viscosity of immiscible Al-In alloys was measured using an oscillating-cup viscometer. It has been found that the viscosity of Al-In melts changes abruptly at the critical temperature of liquid-liquid phase separation during the cooling process. The experimental data above the temperature of phase separation are fitted to the Arrhenius equation. The fitted results show that the temperature dependence of the viscosity obeys the Arrhenius relationship.

  3. Strengthening mechanisms in an Al-Fe-Cr-Ti nano-quasicrystalline alloy and composites

    OpenAIRE

    Pedrazzini, S; Galano, M; Audebert, F.; Collins, DM; Hofmann, F.; Abbey, B.; Korsunsky, A; Lieblich, M.; Garcia Escorial, A.; G. Smith

    2016-01-01

    We report a study of the structure-processing-property relationships in a high strength Al93Fe3Cr2Ti2 nano-quasicrystalline alloy and composites containing 10 and 20 vol.% ductilising pure Al fibres. The superimposed contributions of several different strengthening mechanisms have been modelled analytically using data obtained from systematic characterisation of the monolithic alloy bar. An observed yield strength of 544 MPa has been substantiated from a combination of solid solution strength...

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

    Institute of Scientific and Technical Information of China (English)

    许志武; 闫久春; 吕世雄; 杨士勤

    2004-01-01

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

  5. Close partner relationships

    Directory of Open Access Journals (Sweden)

    Stefanović-Stanojević Tatjana Z.

    2002-01-01

    Full Text Available According to the theory of emotional attachment, specific emotional relationships are being established at an early age between a child and its parents. On the basis of the quality of these relationships the child creates the so-called internal working model ie the image of itself as well as others. The working model persists throughout one's lifetime, shaping in part the quality of adult relationships. Thus, a dominant adult relationship is a close, partner or love one. Within the indicated theoretical context, we were interested in finding out whether there is a statistically significant link between the emotional ties of parents and their children formed in early childhood. The investigation included 180 grown-ups of the same sex and age. For investigating close partner relationships the test Experience in Close Relationship by the American authors (Brenan K.A., Clark C.L., & Shaver P.R. 1998. was used, while the early emotional relationships were investigated using a test which has been the only one so far to measure this quality in adults - Adult Attachment Interview, (Main M., Casidy J., & Kaplan N., 1985. The results show there is a statistically significant link between the observed variables.

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

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, B.

    2003-07-01

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

  7. Memahami Tasawuf Ibnuu Arabi dan Ibnuu al Farid: Konsep al Hubb Illahi, Wahdat al Wujud, Wahdah al Syuhud dan Wahdat al Adyan

    Directory of Open Access Journals (Sweden)

    Muhammad Robith Fuadi

    2013-12-01

    Full Text Available Kaum sufi menapaki jalan yang berbeda untuk menuju hakikat, mereka tidak menggunakan akal dan rasio untuk sampai pada hakikat. Akan tetapi, akal bukan satu-satunya jalan untuk menuju hakikat. Karena kita sering melihat sesuatu yang di luar jangkauan akal dalam hidup ini. Jalan yang ditempuh kaum sufi untuk menuju hakikat seperti kasyf, dzauq, 'iyan, musyahadah dan sebagainya dinilai sebagai sesuatu yang samar, tidak mempunyai batasan dan kaidah pasti, bahkan sering kali bercampur dengan igauan, mimpi, khayalan dan angan-angan. Tapi yang perlu kita ingat adalah bahwa media-media tersebut telah mampu menuntun manusia untuk memecahkan sesuatu yang tidak bisa dipecahkan oleh akal dan hukum-hukum fisika. Tulisan ini akan mengkaji gagasan-gagasan dua tokoh tasawuf besar yaitu Ibnu Arabi dan Ibnu al-Farid yang hidup  pada abad keenam dan ketujuh Hijriah. Tulisan ini secara spesifik akan mengkaji tiga gagasan penting ke dua tokoh tersebut. Yaitu al hubb al Ilahi, wahdat al Wujud dan wahdat al adyan.

  8. On misleading solar-climate relationship

    Directory of Open Access Journals (Sweden)

    B. Legras

    2010-05-01

    Full Text Available A key issue of climate change is to identify the forcings and their relative contributions. Solar-climate relationship is currently the matter of a fierce debate. We address here the need for high quality observations and adequate statistical approach. A recent work by Le Mouël et al. (2010 and its companion paper by Kossobokov et al. (2010 show spectacular correlations between solar activity and meteorological parameters. We question both the data and the method used in these works. We stress 1 that correlation with solar forcing alone is meaningless unless other forcings are properly accounted and that sunspot counting is a poor indicator of solar irradiance, 2 that long series of temperature require homogenization to remove historical artefacts that affect long term variability, 3 that incorrect application of statistical tests leads to interpret as significant a signal which arises from pure random fluctuations. As a consequence, we reject the results and the conclusions of Le Mouël et al. (2010 and Kossobokov et al. (2010. We believe that our contribution bears some general interest in removing confusion from the scientific debate.

  9. ECOLOGICAL ECONOMICS VS ECONOMIC(AL ECOLOGY

    Directory of Open Access Journals (Sweden)

    G. Kharlamova

    2015-10-01

    Full Text Available Currently world faces the dilemma – ecological economy or economic(al ecology. The researchers produce hundreds of surveys on the topic. However the analyses of recent most cited simulations had shown the diversity of results. Thus, for some states the Kuznets environmental curve has place, for others – no. Same could be said about different years for the same state. It provokes the necessity of drawing new group analyses to reveal the tendencies and relationships between economic and environmental factors. Most flexible and mirror factor of environmental sustainability is the volume of CO2 emissions. The econometric analysis was used for detecting the economic impact on this indicator at the global level and in the spectra of group of states depending on their income. The hypothesis of the existence of environmental Kuznets curve for the analysed data is rejected. Real GDP per capita impact on carbon dioxide emissions is considered only at the global level. The impact of openness of the economy is weak. Rejection happened also to the hypothesis that for the developed countries there is a reverse dependence between the environmental pollution and economic openness. Indicator “energy consumption per capita” impacts on greenhouse gas emissions only in countries with high income. Whereby it should be noted that the more developed a country is, the more elastic is this influence. These results have a potential usage for environmental policy regulation and climate strategy.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  11. 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.

  12. The relationship between Business Strategy, IT Strategy and Alignment Capability

    NARCIS (Netherlands)

    Silvius, A.J.G.

    2009-01-01

    Aligning business and IT strategy is a prominent area of concern. Organizations that successfully align their business strategy and their IT strategy, outperform their non-aligned peers (Chan et al., 1997). This chapter explores the relationship between business strategy, IT strategy and alignment c

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

    Institute of Scientific and Technical Information of China (English)

    Maja VONINA; Joef MEDVED; Tonica BONINA; Franc ZUPANI

    2014-01-01

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

  14. A Solid Relationship

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    May 21 marks the 55th anniversary of the establishment of diplomatic relations between China and Pakistan. This bilateral relationship has stood the test of time and may well serve as an exemplary model in contemporary international relations.

  15. Reply to Pachai et al.

    Science.gov (United States)

    Harrison, William J; Bex, Peter J

    2016-05-01

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

  16. Reply to Pachai et al.

    Science.gov (United States)

    Harrison, William J; Bex, Peter J

    2016-05-01

    Peripheral vision is fundamentally limited by the spacing between objects. When asked to report a target's identity, observers make erroneous reports that sometimes match the identity of a nearby distractor and sometimes match a combination of target and distractor features. The classification of these errors has previously been used to support competing 'substitution' [1] or 'averaging' [2] models of the phenomenon known as 'visual crowding'. We recently proposed a single model in which both classes of error occur because observers make their reports by sampling from a biologically-plausible population of weighted responses within a region of space around the target [3]. It is critical to note that there is no probabilistic substitution or averaging process in our model; instead, we argue that neither substitution nor averaging occur, but that these are misclassifications of the distribution of reports that emerge when a population response distribution is sampled. This is a fundamentally different way of thinking about crowding, and on this basis we claim to have provided a mechanism unifying categorically distinct perceptual errors. Our goal was not to model all crowding phenomena, such as the release from crowding when target and flanks differ in color or depth [4]. Pachai et al.[5] have suggested that our model is not unifying because it inaccurately predicts perceptual performance for a particular stimulus. Although we agree that our model does not predict their data, this specific demonstration overlooks the critical aspect of the model: perceptual reports are drawn from a weighted population code. We show that Pachai et al.'s [5] own data actually provide evidence for the population code we have described [3], and we suggest a biologically-plausible analysis of their stimuli that provides a computational basis for their 'grouping' account of crowding. PMID:27166690

  17. Structural characteristics of single crystalline GaN films grown on (111) diamond with AlN buffer

    DEFF Research Database (Denmark)

    Pécz, Béla; Tóth, Lajos; Barna, Árpád;

    2013-01-01

    , eliminated the inversion domains and reduced the density of threading dislocations in the GaN epilayers. The films have an in-plane epitaxial relationship [1010]GaN//[110]diamond. Thus GaN (0001) thin films of single epitaxial relationship and of single polarity were realised on diamond with AlN buffer....

  18. Human-Forest Relationships

    DEFF Research Database (Denmark)

    Ritter, Eva; Dauksta, Dainis

    2012-01-01

    The relationship between forests and people goes back to the early development of civilisation. However, parallel with technical innovations and an increasing urbanisation of the society, an alienation from nature has taken place......The relationship between forests and people goes back to the early development of civilisation. However, parallel with technical innovations and an increasing urbanisation of the society, an alienation from nature has taken place...

  19. Interaction, Relationships And Networks

    OpenAIRE

    Benson-Rea, M

    1999-01-01

    This paper presents four case studies which have been selected to represent different insights into the strategic evaluation of relationships within one industry. From an analysis of how each of the case study firms has formed its networks of relationships, within its overall approach to industry strategy, we discuss how the interactions are evaluated, with a particular emergent focus on social or actor bonds. The strategy literature models strategy formation processes and content. The networ...

  20. Romantic Relationships and Love

    OpenAIRE

    Hasan Atak; Nuray Tastan

    2012-01-01

    Intimacy or love is completely defined as a personal relationship or sometimes a specific component of personal relationships or even a particular emotion that someone feels for another. Love is appearing as a psychological concept in the area of psychology in recent years. The definition of love depends on culture and people. Love comes with the concepts such as intimacy, attachment, respect and mature love. In this context, love is evaluated conceptually in this paper in order to fill the l...

  1. RELATIONSHIP MARKETING - THEORETICAL CONSIDERATION

    OpenAIRE

    Iacob Catoiu; Mihai Tichindelean

    2012-01-01

    The purpose of the paper is to propose a set of research perspectives for therelationship marketing theory. A comprehensive literature review is undertaken which entails threedifferent understandings of relationship marketing. First, relationship marketing is considered as amarketing strategy within the unifying theory of the service dominant logic. Second, relationshipmarketing is presented as the new understanding or paradigm of marketing. Third, relationshipmarketing theory is correlated a...

  2. Customer Relationship Management

    OpenAIRE

    Conf. univ. dr. Enache Elena; Asist. univ. drd. Marin Carmen; Conf. univ. dr. Vechiu Camelia

    2010-01-01

    The most significant changes in the practice of marketing during the last decade in the shift in emphasis from a transaction orientation to the customer relationship management (CRM). Customer relationship management is a strategy of organization to identifying the main desire of the customer and the behaviour commercial business, the beneficial use of information acquired in order to improve relations with these factors, with the objective of increasing customer satisfaction requirements.

  3. The Al-Al3Ni Eutectic Reaction: Crystallography and Mechanism of Formation

    Science.gov (United States)

    Fan, Yangyang; Makhlouf, Makhlouf M.

    2015-09-01

    The characteristics of the Al-Al3Ni eutectic structure are examined with emphasis on its morphology and crystallography. Based on these examinations, the mechanism of formation of this technologically important eutectic is postulated. It is found that a thin shell of α-Al forms coherently around each Al3Ni fiber. The excellent thermal stability of the Al-Al3Ni eutectic may be attributed to the presence of this coherent layer.

  4. Comment on "Worldwide evidence of a unimodal relationship between productivity and plant species richness"

    Science.gov (United States)

    Tredennick, Andrew T; Adler, Peter B.; Grace, James B.; Harpole, W Stanley; Borer, Elizabeth T.; Seabloom, Eric W.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Chu, Cheng-Jin; Collins, Scott L.; Crawley, Michael J.; Fay, Philip A.; Firn, Jennifer; Gruner, Daniel S.; Hagenah, Nicole; Hautier, Yann; Hector, Andy; Hillebrand, Helmut; Kirkman, Kevin P.; Knops, Johannes M. H.; Laungani, Ramesh; Lind, Eric M.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Orrock, John L.; Peri, Pablo L.; Prober, Suzanne M.; Risch, Anita C.; Schuetz, Martin; Speziale, Karina L.; Standish, Rachel J.; Sullivan, Lauren L.; Wardle, Glenda M.; Williams, Ryan J.; Yang, Louie H.

    2016-01-01

    Fraser et al. (Reports, 17 July 2015, p. 302) report a unimodal relationship between productivity and species richness at regional and global scales, which they contrast with the results of Adler et al. (Reports, 23 September 2011, p. 1750). However, both data sets, when analyzed correctly, show clearly and consistently that productivity is a poor predictor of local species richness.

  5. The aluminum electrode in AlCl3-alkali-halide melts.

    Science.gov (United States)

    Holleck, G. L.; Giner, J.

    1972-01-01

    Passivation phenomena have been observed upon cathodic and anodic polarization of the Al electrode in AlCl3-KCl-NaCl melts between 100 and 160 C. They are caused by formation of a solid salt layer at the electrode surface resulting from concentration changes upon current flow. The anodic limiting currents increased with temperature and with decreasing AlCl3 content of the melt. Current voltage curves obtained on a rotating aluminum disk showed a linear relationship between the anodic limiting current and omega to the minus 1/2 power. Upon cathodic polarization, dendrite formation occurs at the Al electrode. The activation overvoltage in AlCl3-KCl-NaCl was determined by galvanostatic current step methods. An apparent exchange current density of 270 mA/sq cm at 130 C and a double layer capacity of 40 plus or minus 10 microfarad/sq cm were measured.

  6. The two steps thermal decomposition of titanium hydride and two steps foaming of Al alloy

    Institute of Scientific and Technical Information of China (English)

    SHANG Jintang; HE Deping

    2005-01-01

    Two steps foaming (TSF) technique was proposed to prepare shaped Al alloy foam. Based on the thermal decomposition kinetics equation of titanium hydride, the relationship between two steps thermal decomposition kinetics of titanium hydride and two steps foaming Al alloy melt was studied. Two steps thermal decomposition curve of titanium hydride under increasing and constant temperature was calculated respectively. The hydrogen mass needed in the second foaming step was also calculated. Results showed that the hydrogen mass of the second thermal decomposition of titanium hydride is enough for the second foaming step in the condition of as-received Al melt foaming. Experimental and theoretical results indicate that two steps foaming technique can be used to prepare Al alloy foam with high porosity, shaped components and sandwich with Al alloy foam core.

  7. Microstructure and Mechanical Properties of Nano-crystalline Al-8 wt pct Ni Alloy

    Institute of Scientific and Technical Information of China (English)

    M.Abou Zied

    2006-01-01

    Microstructure and mechanical properties of ball-milled Al-8 wt pct Ni ribbon have been investigated by X-ray diffraction(XRD)and continuous Vickers hardness test, respectively. The results indicate that, the main phases of this alloy are α-Al and orthorhombic-Al3Ni. The lattice parameter of α-Al increases with increasing milling time. From the elastic constant of Al, the average contrast factors of the(111),(200),(220),(311)and system were calculated. The average grain size and dislocation parameters as a function of milling time have been investigated using the modified Williamson-Hall plot and the Warren-Averbach equation, respectively.An attempt has been made to correlate the micro-hardness of milled ribbon with their grain size through the Hall-Patch relationship:HV0.01=742.45〈D〉-1/2+401.55(kg/mm2).

  8. Epitaxial growth of AlN on single crystal Mo substrates

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Koichiro; Inoue, Shigeru [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 (Japan); Nakano, Takayuki; Kim, Tae-Won [Kanagawa Academy of Science and Technology (KAST) KSP east 301, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012 (Japan); Oshima, Masaharu [Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Fujioka, Hiroshi [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 (Japan); Kanagawa Academy of Science and Technology (KAST) KSP east 301, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012 (Japan)], E-mail: hfujioka@iis.u-tokyo.ac.jp

    2008-06-02

    We have grown AlN films on single-crystalline Mo(110), (100), and (111) substrates using a low temperature pulsed laser deposition (PLD) growth technique and investigated their structural properties. Although c-axis oriented AlN films grow on Mo(100), the films contain 30{sup o} rotated domains due to the difference in the rotational symmetry between AlN(0001) and Mo(100). AlN films with only poor crystalline quality grow on Mo(111) substrates, probably due to the poor surface morphology and high reactivity of the substrates. On the other hand, single crystal AlN films grow epitaxially on Mo(110) substrates with an in-plane relationship of AlN[11-20] // Mo[001]. Reflection high-energy electron diffraction or electron backscattered diffraction analysis has revealed that neither in-plane 30 deg. rotated domains nor cubic phase domains exist in the AlN films. X-ray reflectivity measurements have revealed that the heterointerface between AlN and Mo prepared by PLD at 450 deg. C is quite abrupt. These results indicate that PLD epitaxial growth of AlN on single crystal Mo substrates is quite promising for the fabrication of future high frequency filter devices.

  9. The epidemiology of ALS: a conspiracy of genes, environment and time.

    Science.gov (United States)

    Al-Chalabi, Ammar; Hardiman, Orla

    2013-11-01

    Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive neurodegenerative disease of motor neurons, resulting in worsening weakness of voluntary muscles until death from respiratory failure occurs after about 3 years. Although great advances have been made in our understanding of the genetic causes of ALS, the contribution of environmental factors has been more difficult to assess. Large-scale studies of the clinical patterns of ALS, individual histories preceding the onset of ALS, and the rates of ALS in different populations and groups have led to improved patient care, but have not yet revealed a replicable, definitive environmental risk factor. In this Review, we outline what is currently known of the environmental and genetic epidemiology of ALS, describe the current state of the art with respect to the different types of ALS, and explore whether ALS should be considered a single disease or a syndrome. We examine the relationship between genetic and environmental risk factors, and propose a disease model in which ALS is considered to be the result of environmental risks and time acting on a pre-existing genetic load, followed by an automatic, self-perpetuating decline to death. PMID:24126629

  10. Formaline of alternatieven als ontsmettingsmiddel voor broedeieren

    OpenAIRE

    Meijerhof, R.; Dijk, D. van

    1997-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    En-zhao Wang; Xiang-fa Liu

    2015-01-01

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

  12. Nocturnal hypoxia in ALS is related to cognitive dysfunction and can occur as clusters of desaturations.

    Directory of Open Access Journals (Sweden)

    Su-Yeon Park

    Full Text Available BACKGROUND: Amyotrophic lateral sclerosis (ALS is a neurodegenerative disease that leads to progressive weakness of the respiratory and limb muscles. Consequently, most patients with ALS exhibit progressive hypoventilation, which worsens during sleep. The aim of this study was to evaluate the relationship between nocturnal hypoxia and cognitive dysfunction and to assess the pattern of nocturnal hypoxia in patients with ALS. METHOD: Twenty-five patients with definite or probable ALS underwent neuropsychologic testing, nocturnal pulse oximetry, and capnography. Patients were grouped according to the presence of nocturnal hypoxia (SpO2<95% for ≥10% of the night and their clinical characteristics and cognitive function were compared. RESULTS: Compared to patients without nocturnal hypoxia, those with nocturnal hypoxia (n = 10, 40% had poor memory retention (p = 0.039 and retrieval efficiency (p = 0.045. A cluster-of-desaturation pattern was identified in 7 patients (70% in the Hypoxia Group. CONCLUSIONS: These results suggest that nocturnal hypoxia can be related to cognitive dysfunction in ALS. In addition, a considerable number of patients with ALS may be exposed to repeated episodes of deoxygenation-reoxygenation (a cluster-of-desaturation pattern during sleep, which could be associated with the generation of reactive oxygen species. Further studies are required to define the exact causal relationships between these phenomena, the exact manifestations of nocturnal cluster-of-desaturation patterns, and the effect of clusters of desaturation on ALS progression.

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

    Directory of Open Access Journals (Sweden)

    Angela Kok-Van Meer

    2014-06-01

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

  14. AlON-SiAlON复合材料的制备及特性%Preparation and properties of AlON-SiAlON composites

    Institute of Scientific and Technical Information of China (English)

    山下敬; 山口明良

    2003-01-01

    为提高AlON陶瓷材料的抗氧化性能,制备了AlON-SiAl7O2N7复相材料.在1750℃、0.5 MPa的N2气氛中,保温2 h烧成不同Al2O3/AlN/Si3N4配比的原料得到不同AlON/SiAl7O2N7比的复相材料.因为在烧结SiAl7O2N7的过程中,蒸发-凝聚的同时伴随着SiO气体的挥发,因此很难得到致密的AlON-SiAl7O2N7复相材料.研究了AlON-SiAl7O2N7复相材料在1300℃、空气中的抗氧化性能,同时作为比较,研究了相同条件下单相的AlON材料的抗氧化性能.结果表明,AlON-SiAl7O2N7复相材料显示了较之单相的AlON陶瓷材料更好的抗氧化性能,这是因为氧化过程中所形成的含玻璃相的表面氧化层抑制了氧的向内扩散所致.

  15. Customer relationship management

    NARCIS (Netherlands)

    Peelen, E.

    2006-01-01

    CRM is tegenwoordig een bekende term in het bedrijfsleven, maar het is voor organisaties niet altijd duidelijk hoe ze er invulling aan moeten geven. Ze worstelen met vragen als: Wat willen we werkelijk bereiken met CRM? Willen we een klantgerichte organisatie? Wat moeten we doen om deze te krijgen?

  16. con bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Adriana Mora Antó

    2005-01-01

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

  17. Topiramat als Phasenprophylaktikum - ein Fallbericht

    Directory of Open Access Journals (Sweden)

    Letmaier M

    2001-01-01

    Full Text Available Topiramat ist ein neues Antiepileptikum mit einem breiten Wirkspektrum. Aktuelle klinische Studien geben Hinweise darauf, daß Topiramat stimmungsstabilisierende Eigenschaften besitzt und somit effizient in der Behandlung der bipolaren affektiven Störung sein könnte. Vor dem Hintergrund dieser Studienberichte, behandelten wir eine 41jährige, erstmals vor 10 Jahren erkrankte Patientin mit der Diagnose einer therapierefraktären, bipolaren affektiven Störung (Rapid-Cycling mit Topiramat. Im Rahmen ihrer Erkrankung wurde die Patientin insgesamt 12mal stationär aufgenommen und meist aufgrund von akuten manischen Episoden behandelt. Dabei kamen seit 1991 folgende Phasenprophylaktika zur Anwendung: Carbamazepin, Valproat und Lamotrigin ? zuletzt nur mit mäßigem Erfolg. Daraufhin wurde zu Beginn einer neuerlichen manischen Episode ambulant eine Therapie mit Topiramat begonnen. Acht Wochen nach Therapiestart kam die Patientin in stationäre Behandlung. Der Aufenthalt dauerte weniger als drei Wochen; Topiramat wurde von der Patientin gut vertragen. Infolge eines belastenden Lebensereignisses kam es unter kontinuierlicher Therapie mit Topiramat zu einer Destabilisierung des psychischen Zustandsbildes (manische Symptome. Durch eine ambulante Erhöhung der Topiramatdosis bei gleichzeitiger Gabe von Risperidon und Clonazepam konnte jedoch eine neuerliche manische Episode erstmals ambulant behandelt werden. Die Patientin erhält derzeit 200 mg Topiramat pro Tag und ist seit mehr als 20 Monaten nahezu beschwerdefrei.

  18. Nonstoichiometry of Al-Zr intermetallic phases

    Energy Technology Data Exchange (ETDEWEB)

    Radmilovic, V.; Thomas, G.

    1994-06-01

    Nonstoichiometry of metastable cubic {beta}{prime} and equilibrium tetragonal {beta} Al-Zr intermetallic phases of the nominal composition Al{sub 3}Zr in Al-rich alloys has been extensively studied. It is proposed that the ``dark contrast`` of {beta}{prime} core in {beta}{prime}/{sigma}{prime} complex precipitates, in Al-Li-Zr based alloys, is caused by incorporation of Al and Li atoms into the {beta}{prime} phase on Zr sublattice sites, forming nonstoichiometric Al-Zr intermetallic phases, rather than by Li partitioning only. {beta}{prime} particles contain very small amounts of Zr, approximately 5 at.%, much less than the stoichiometric 25 at.% in the Al{sub 3}Zr metastable phase. These particles are, according to simulation of high resolution images, of the Al{sub 3}(Al{sub 0.4}Li{sub 0.4}Zr{sub 0.2}) type. Nonstoichiometric particles of average composition Al{sub 4}Zr and Al{sub 6}Zr are observed also in the binary Al-Zr alloy, even after annealing for several hours at 600{degree}C.

  19. Electroplating Zn-Al Alloy Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

  1. Conflict resolution in adolescent relationships

    NARCIS (Netherlands)

    van Doorn, M.D.

    2008-01-01

    Conflict is an inevitable feature of social relationships. When people interact, disagreements may arise. Especially in close relationships, people sometimes disagree. Although conflict might jeopardize relationships, conflict is not necessarily detrimental. The way conflicts are handled is importan

  2. Microstructure, precipitates and compressive properties of various holmium doped NiAl/Cr(Mo, Hf) eutectic alloys

    International Nuclear Information System (INIS)

    Highlights: → Trace Ho addition optimizes the microstructure of the NiAl/Cr(Mo, Hf) eutectic alloy. → An orientation relationship of [120]Ni2A13Ho//[111]NiA1 and (002-bar)Ni2A13Ho//(11-bar0)NiA1 is found. → Ho addition promotes the precipitation of Ni2AlHf Heusler phase. → Minor Ho addition coarsens the microstructure, especially the intercellular region. → More Ho addition changes the original cellular eutectic microstructure. -- Abstract: The microstructure and mechanical properties of NiAl-28Cr-6Mo-0.2Hf eutectic alloys with various holmium additions have been investigated by using of SEM, TEM and compression test. The results reveal that minor Ho addition could optimize the microstructure by refining the lamella inside of eutectic cell and controlling the coarsening of intercellular region. However the minor Ho addition results in the Ni2Al3Ho phase, which has hexagonal crystal structure and an orientation relationship with NiAl phase of [120]Ni2Al3Ho//[111]NiAl and (002-bar)Ni2Al3Ho//(11-bar0)NiAl. Moreover the Ni17Ho2 phase is found in the Ni2Al3Ho phase, which has twin crystal inside and an orientation relationship with Ni2Al3Ho phase of [123]Al17Ho2//[124]Ni2Al3Ho and (111-bar)Al17Ho2//(2-bar10)Ni2Al3Ho. In addition, the Ho addition promotes the precipitation of Ni2AlHf phase. More Ho addition coarsens the Cr(Mo) phases along the intercellular and results in more strengthening precipitates inside eutectic cell. When the Ho addition comes to 0.5 at.%, the alloy almost loses the cellular eutectic characteristic and exhibits a microstructure with coarse NiAl, massive Cr(Mo) and Ni2Al3Ho phases. The microstructure optimizations improve the mechanical properties of the alloy significantly, especially the alloy with 0.1 at.% Ho content.

  3. A comparative first-principles study on electronic structures and mechanical properties of ternary intermetallic compounds Al8Cr4Y and Al8Cu4Y: Pressure and tension effects

    Science.gov (United States)

    Yang, Wenchao; Pang, Mingjun; Tan, Yong; Zhan, Yongzhong

    2016-11-01

    An investigation into the bulk properties, elastic properties and Debye temperature under pressure, and deformation mode under tension of Al8Cu4Y and Al8Cr4Y compounds was investigated by using first principles calculations based on density functional theory. The calculated lattice constants for the ternary compounds (Al8Cu4Y and Al8Cr4Y) are in good agreement with the experimental data. It can be seen from interatomic distances that the bonding between Al1 atom and Cr, Y, and Al2 atoms in Al8Cr4Y are stronger than Al8Cu4Y. The results of cohesive energy show that Al8Cr4Y should be easier to be formed and much stronger chemical bonds than Al8Cu4Y. The bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio ν can be obtained by using the Voigt-Reuss-Hill averaging scheme. From the results of elastic properties, Al8Cr4Y has the stronger mechanical behavior than Al8Cu4Y. Our calculations also show that pressure has a greater effect on mechanical behavior for both compounds. The ideal tensile strength are obtained by stress-strain relationships under [001](001) uniaxial tensile deformation, which are 15.4 and 23.4 GPa for Al8Cu4Y and Al8Cr4Y, respectively. The total and partial density of states and electron charge density under uniaxial tensile deformations for Al8Cu4Y and Al8Cr4Y compounds are also calculated and discussed in this work.

  4. Progresses in analyzing 26Al with SMCAMS

    International Nuclear Information System (INIS)

    Shanghai Mini-Cyclotron based Accelerator Mass Spectrometer (SMCAMS) was especially designed for analyzing 14C. In order to accelerate and analyze 26Al the accelerated orbit and beam optics in injection system were calculated and harmonic number and acceleration turns was optimized. Preliminary experiment was carried out. In which a beam current of 1.15 x 10-9A for 27Al- and 0.038 CPS background for 26Al were measured. The limited sensitivity of 26Al/27Al is 5.25 x 10-12. (authors)

  5. Exploring Entrepreneurial Network Relationships

    DEFF Research Database (Denmark)

    Norus, Jesper

    2003-01-01

    the institutional and organizational origins are to be touched upon to come to understand the nature of the biotechnology environment and the actors involved. The positioning of the SBFs as the focal point of the analysis leads to a discussion on entrepreneurial business strategies in biotechnology industry and how...... theories and a dynamic view of network relations. That is done in order to capture the nature of the relationships between different types of actors, but also in order to emphasize the informal nature of some of these relationships.The article has a dual purpose; 1) From a corporate point of view...... to emphasize multiple conditions for developing and forming interorganizational relationships, 2) From a research perspective to point to the diversity and heterogeneity of these relations and thereby emphasizes the evolutionary nature of these relations and their relatedness to the overall strategies obtained...

  6. Internet mediated adolescent relationships

    Directory of Open Access Journals (Sweden)

    Fabrício de Souza

    2010-06-01

    Full Text Available This paper aims to contribute towards the comprehension of the adhesion of adolescent to digital technologies and their usage in the search for or consolidation of relationships with their peers. The objective was to analyze the role of blogs in the maintenance and establishment of relationships among adolescents from the State of Espírito Santo, Brazil. Three boys’ blogs and three girls’ blogs were selected, and five pages of each blog were selected, in a total of 30 pages. Categories were elaborated from reading the posts left at the 30 pages and subsequently used to classify and quantify the posts. Messages and comments left at the blogs had a positive affective connotation, in search for approximation and contact with the blog owner. Messages were also noted for gender differences. It was concluded that some determined patterns of offline interaction guided the establishment of online relationships.

  7. Cross border relationships

    DEFF Research Database (Denmark)

    Singla, Rashmi; Sriram, Sujata

    2010-01-01

    in which they were born. These movements also imply human relationships across the borders in different contexts with various cultural, psychological consequences. Relationships of members of migrant groups with each other, and also with the host community have important implications on the health and well......-being of not just the migrant population, but also the host communities. These relationships represent the microcosm of societal and cultural integration and cohesion at the broader levels. Studies of how and how well migrants, especially youth handle migration indicate transformations in paradigms as both...... acculturative stress and developmental possibilities are realities experienced in the search of new worlds and new opportunities. The symposia will include such changes from Denmark, India, UK and the USA, covering theoretical, methodological issues including the ethical aspects. Themes involved in crossing...

  8. Trato verbal paterno al adolescente

    Directory of Open Access Journals (Sweden)

    Rodríguez Juan Carlos

    1995-06-01

    Full Text Available

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

     

  9. Entscheidung als Häresie

    Directory of Open Access Journals (Sweden)

    Jaanus Sooväli

    2014-06-01

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

  10. Hábitos alimentarios y su relación con los conocimientos, respecto al concepto de dieta equilibrada, de un colectivo de mujeres jóvenes con sobrepeso/obesidad Dietary habits and their relationship with the knowledge on the concept of a balanced diet in a group of young women with overweight/obesity

    Directory of Open Access Journals (Sweden)

    E. Rodríguez-Rodríguez

    2007-12-01

    Full Text Available Objetivo: Conocer los hábitos de alimentación de una población de mujeres con sobrepeso/obesidad y sus conocimientos sobre el concepto de alimentación correcta para poder diseñar campañas de educación nutricional dirigidas a este colectivo. Material y métodos: Se ha estudiado un colectivo de 67 mujeres de 20 a 35 años y con Índice de Masa Corporal entre 24 y 35 kg/m², que fueron interrogados sobre su frecuencia de consumo de alimentos, junto con la que consideraban correcta para lograr una alimentación equilibrada. Resultados: Las mujeres estudiadas consumían con mayor frecuencia aceites (4,3 ± 4,5 veces/semana y dulces (2,5 ± 3,6 veces/semana y menos veces agua (-19,1 ± 22,7 veces/semana, verduras (-4,3 ± 5,7 veces/semana, frutas (-3,7 ± 6,2 veces/semana, legumbres (-1,3 ± 2,0 veces/semana y pescado (-2,2 ± 3,7 veces/semana de lo que creían que debían consumir. Al comparar lo que declaran consumir con lo marcado como consumo mínimo aconsejable para los diferentes grupos de alimentos, se comprueba que es necesario aumentar el consumo de cereales y legumbres, el de frutas y verduras y, en menor media el de pescados y huevos. Conclusiones: Ante los hábitos alimentarios incorrectos observados en la población con sobrepeso/obesidad, sería conveniente realizar campañas de educación nutricional. Con esta educación se podría mejorar la dieta de toda la población y se evitaría, en muchos casos, la aparición de sobrepeso y obesidad. Además, en los casos en los que ya estuviera presente dicha patología, se evitaría el seguimiento de pautas que suelen ser perjudiciales para la salud y también para el control de peso.Objective: To know the dietary habits of a population of women with overweight/obesity and their knowledge on the concept of proper feeding in order to design nutrition educational campaigns focused on this population. Materials and methods: A group of 67 women, aged 20 to 35 years with body mass index 24

  11. STUDY OF THE Al/GRAPHITE INTERFACE

    Institute of Scientific and Technical Information of China (English)

    LU HUA(陆华); SHEN DIAN-HONG(沈电洪); DENG XIN-FA(邓新发); XUE QI-KUN(薛其坤); N.FROUMIN; M.POLAK

    2001-01-01

    Thin Al films with a thickness of 20-30nm were prepared by ltra-high vacuum deposition of Al onto a graphite surface arallel to a (0001) basal plane. The samples were annealed up to 1070K. X-ray photoelectron spectroscopy analysis has shown that for temperatures just higher than 770K, a little carbide occurs in the Al film and only an AI-C phase is present at the Al/graphite interface. After nnealing at 970K, the Al4C3 phase can be observed, and the binding energy of the Al2p electrons increases continuously from 72.7 to 74.2eV with increasing temperature up to 1070K. Auger electron spectroscopy depth profiles are measured to investigate the phases existing in the Al film as well as at the Al/graphite interface. It is found that the Al4C3 hase at the interface is the final product of a series of Al carbides from the interfacial reaction between Al and graphite.

  12. AlON粉体的合成

    Institute of Scientific and Technical Information of China (English)

    赵小军; 茹红强; 张宁; 孙有政

    2009-01-01

    以α-Al2O3和AlN为原料,利用高温固相反应在氮气气氛下常压合成了AlON粉体。研究了成分配比、合成温度、保温时间对合成AlON粉体含量的影响,并通过热分析测试了合成过程热流和质量的变化。结果表明,当原料Al2O3和AlN的质量比为81:18、合成工艺为1750℃,2h时,得到AlON相的含量达到95%以上。

  13. Response to Comment on "Worldwide evidence of a unimodal relationship between productivity and plant species richness".

    Science.gov (United States)

    Pither, Jason; Fraser, Lauchlan H; Jentsch, Anke; Sternberg, Marcelo; Zobel, Martin; Cahill, James; Beierkuhnlein, Carl; Bartha, Sándor; Bennett, Jonathan A; Boldgiv, Bazartseren; Brown, Leslie R; Cabido, Marcelo; Campetella, Giandiego; Carlyle, Cameron N; Chelli, Stefano; Csergő, Anna Mária; Diaz, Sandra; Enrico, Lucas; Ensing, David; Fidelis, Alessandra; Garris, Heath W; Henry, Hugh A L; Höhn, Maria; Klironomos, John; Koorem, Kadri; Lawrence-Lodge, Rachael; Manning, Peter; Mitchell, Randall J; Moora, Mari; Pillar, Valério D; Stotz, Gisela C; Sugiyama, Shu-ichi; Szentes, Szilárd; Tungalag, Radnaakhand; Undrakhbold, Sainbileg; Wellstein, Camilla; Zupo, Talita

    2016-01-29

    Tredennick et al. criticize one of our statistical analyses and emphasize the low explanatory power of models relating productivity to diversity. These criticisms do not detract from our key findings, including evidence consistent with the unimodal constraint relationship predicted by the humped-back model and evidence of scale sensitivities in the form and strength of the relationship.

  14. Response to Comment on "Worldwide evidence of a unimodal relationship between productivity and plant species richness".

    Science.gov (United States)

    Pither, Jason; Fraser, Lauchlan H; Jentsch, Anke; Sternberg, Marcelo; Zobel, Martin; Cahill, James; Beierkuhnlein, Carl; Bartha, Sándor; Bennett, Jonathan A; Boldgiv, Bazartseren; Brown, Leslie R; Cabido, Marcelo; Campetella, Giandiego; Carlyle, Cameron N; Chelli, Stefano; Csergő, Anna Mária; Diaz, Sandra; Enrico, Lucas; Ensing, David; Fidelis, Alessandra; Garris, Heath W; Henry, Hugh A L; Höhn, Maria; Klironomos, John; Koorem, Kadri; Lawrence-Lodge, Rachael; Manning, Peter; Mitchell, Randall J; Moora, Mari; Pillar, Valério D; Stotz, Gisela C; Sugiyama, Shu-ichi; Szentes, Szilárd; Tungalag, Radnaakhand; Undrakhbold, Sainbileg; Wellstein, Camilla; Zupo, Talita

    2016-01-29

    Tredennick et al. criticize one of our statistical analyses and emphasize the low explanatory power of models relating productivity to diversity. These criticisms do not detract from our key findings, including evidence consistent with the unimodal constraint relationship predicted by the humped-back model and evidence of scale sensitivities in the form and strength of the relationship. PMID:26823419

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

    Directory of Open Access Journals (Sweden)

    Zhijiang Wang

    2015-01-01

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

  16. Organizational Relationship Termination Competence

    DEFF Research Database (Denmark)

    Ritter, Thomas; Geersbro, Jens

    2011-01-01

    termination are found to significantly affect a firm's relationship termination competence. The findings suggest that managers should regard termination as a legitimate option in customer relationship management. In order to decrease the number of unwanted customers, managers must accept termination...... of organizational termination in order to improve our understanding of the management of termination. The impact of these termination dimensions on the percentage of unwanted customers is developed and tested using PLS on data gathered from a cross-sectional survey of more than 800 sales representatives. We find...

  17. Internet mediated adolescent relationships

    OpenAIRE

    Fabrício de Souza; Maria Margarida Pereira Rodrigues

    2010-01-01

    This paper aims to contribute towards the comprehension of the adhesion of adolescent to digital technologies and their usage in the search for or consolidation of relationships with their peers. The objective was to analyze the role of blogs in the maintenance and establishment of relationships among adolescents from the State of Espírito Santo, Brazil. Three boys’ blogs and three girls’ blogs were selected, and five pages of each blog were selected, in a total of 30 pages. Categories were e...

  18. Human-Forest Relationships

    DEFF Research Database (Denmark)

    Ritter, Eva; Dauksta, D.

    2012-01-01

    with the same attention as the other functions. The aim of this paper is to put a stronger emphasis on the fact that the acknowledgement of cultural bonds is needed in the discussion of sustainable development. Forest should not only be considered as a technical means to solve environmental and economic......The relationship between human beings and forests has been important for the development of society. It is based on various productive, ecological, social and cultural functions of forests. The cultural functions, including the spiritual and symbolic role of forests, are often not addressed......, in addition to economic, ecological and social functions, and lead towards a sustainable relationship between forests and society....

  19. Verschwiegene Beziehungen Secret Relationships

    Directory of Open Access Journals (Sweden)

    Monika Ehlers

    2004-07-01

    Full Text Available Dagmar von Hoffs Studie spannt den Bogen vom ethnologischen Tabubegriff über literatur-historische Wandlungen der Inzestthematik und ihrer mythischen Dimensionen bis hin zum Inzest als traumatischer Erfahrung. Inzest wird hierbei als Schwellenerfahrung verstanden, die an die Grenzen des Sagbaren führt und somit literarische Texte wie filmische Umsetzungen in ihren Darstellungsstrategien herausfordert.Dagmar von Hoff’s study spans from an analysis of an ethnological tabu term to the literary and historical transformations of the incest theme and their mythic dimensions to incest as a traumatic experience. Incest is hereby understood as a threshold experience that leads to the boundaries of that which can be spoken and, hence, challenges literary texts, such as film, in their strategies of representation.

  20. Need fulfillment in polyamorous relationships.

    Science.gov (United States)

    Mitchell, Melissa E; Bartholomew, Kim; Cobb, Rebecca J

    2014-01-01

    Polyamory is characterized by simultaneous consensual romantic relationships with multiple partners. Polyamory allows individuals to fulfill their relationship needs with multiple romantic partners, yet researchers have not identified how having needs met in one romantic relationship may be related to relationship outcomes in a concurrent relationship. Polyamorous individuals (N=1,093) completed online measures of need fulfillment, relationship satisfaction, and commitment for two concurrent romantic relationships. Participants reported high levels of need fulfillment and satisfaction in both relationships. Need fulfillment with one partner negatively predicted approximately 1% of the variance in relationship satisfaction with the other partner; however, there was no association between need fulfillment with one partner and commitment to the other. Generally, the findings suggest that polyamorous relationships are relatively independent of one another. This study provides initial evidence that polyamory may be a viable and fulfilling alternative way of conducting intimate relationships.

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

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

    Directory of Open Access Journals (Sweden)

    N. T. Kumbhar

    2012-01-01

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

  3. A Research on relationship between organizational commitment and self respect of personnel working at domestic security services: Turkish Police Constabulary sampleİç Güvenlik Hizmetlerinde Çalışanların örgütsel bağlılık ile benlik saygısı arasındaki ilişki: Türk Polis Teşkilatı Örneklemi

    Directory of Open Access Journals (Sweden)

    Bekir Tavas

    2016-03-01

    Full Text Available In general definition, organizational commitment is an indicator of affiliation level of workers in an organization. Self respect is related with how individuals see themselves. Both organizational commitment and self respect are cognitive properties of individuals. For this reason there may be a relation between organizational commitment and self respect. Thus, relationship between organizational commitment and self respect for domestic security personnel were evaluated in this research. In the research, (n=422 law enforcement agency personnel working at Izmir City police department in 2015 year were subjected to survey including organizational commitment and self respect scales. According to results of the study, harmony factor among organizational commitment factors has significant difference between gender groups (p0,05. Correlation analysis results did not indicate a statistically significant relation between organizational commitment and self respect (p>0,05.   Özet Örgütsel bağlılık, en genel tanımıyla bir örgüt içerisindeki çalışanların, kendilerini o örgüte ne derece ait hissettiklerinin bir göstergesidir. Benlik saygısı ise bireylerin kendi kişiliklerini nasıl gördükleri ile ilişkilidir. Gerek örgütsel bağlılık, gerekse benlik saygısı bireylerin bilişsel özellikleridir. Bu nedenle benlik saygısı ile örgütsel bağlılık arasında ilişki olabilir. Bundan dolayı bu araştırmada, iç güvenlik hizmetleri personelinin örgütsel bağlılık ile benlik saygısı düzeyleri arasındaki ilişki incelenmiştir. Araştırmada, 2015 yılında İzmir İl Emniyet Müdürlüğü bünyesinde görev yapan (n=422 personel üzerinde algılanan örgütsel bağlılık ve benlik saygısı ölçekleri uygulanmıştır. Araştırma sonuçlarına göre katılımcıların örgütsel bağlılık boyutlarından uyum boyutu cinsiyete göre istatistiksel olarak anlamlı farklılık göstermekteyken (p0,05. Benlik sayg

  4. A family of hexagonal and orthorhombic (Al,Si)4Cr approximants of quasicrystals

    International Nuclear Information System (INIS)

    By means of transmission electron microscopy, four crystalline phases with compositions close to (Al,Si)4Cr have been found in Al-Cr-Si alloys. The hexagonal μ'-(Al,Si)4Cr has the same space group P63/mmc as μ-(Al,Si)4Cr, but its c parameter is only one half of cμ. On the other hand, the orthorhombic ε-Al4Cr, ε' - and ε''-(Al,Si)4Cr have about the same lattice parameters but different space groups: Bbmm (or Cmcm), Pbnm and P212121, respectively. The lattice parameters of these phases are closely related: aε,ε',ε''=√3aμ,μ' ≅ 3.46nm; bε,ε',ε''=aμ,μ' ≅ 2.00nm; cε,ε',ε''=1/2cμ=cμ' ≅ 1.24nm. The symmetry of space group decreases from μ(μ'), ε, ε' to ε'' and the space groups of any two neighboring phases have the minimal supergroup and the maximal subgroup relationship. Strong diffraction spots of all these phases exhibit pseudo icosahedral symmetry. In the (001) plane, icodahedra are linked by mutual penetration along the five-fold axis forming icosahedral chains in three directions at 120 deg. apart. These four (Al,Si)4Cr phases together with the ε-Al4Cr are not only structurally close related, but also are approximants of quasicrystals

  5. Diasporic Relationships and Processes

    DEFF Research Database (Denmark)

    Singla, Rashmi

    2010-01-01

    How does moving across the geographical borders affect the relationships of diaspora members both here – in the country of residence and there- in the country of origin? The article delineates some of the processes through gendered experiences of the young adults perceived as active actors based...

  6. China-EU Relationship

    Institute of Scientific and Technical Information of China (English)

    Feng Zhongping; Zhang Yimeng

    2007-01-01

    @@ The China-EU relationship attracted global interest in 2006. On the one hand, cooperation between China and the EU was making good progress, but on the other, there were challenges facing both, leading some international policy analysts to conclude that the honeymoon period between China and the EU was over.

  7. Customer Relationship Management.

    Science.gov (United States)

    Fayerman, Michael

    2002-01-01

    Presents an approach increasingly employed by businesses to track and respond to their customers to provide better and faster services: customer relationship management. Discusses its applicability to the operations of higher education and institutional research and the role it plays in the knowledge management framework. (EV)

  8. Multi-Dimensional Relationship

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Relationships between China and Russia are set to reach new heights during the next two years with the advent of the Russian Year in China (2006) and the Chinese Year in Russia (2007). Russian Ambassador to China Sergey Razov shared his views with Beijing Review about this development in bilateral relations between the two giant neighbors.

  9. An ambiguous relationship

    DEFF Research Database (Denmark)

    Søndergaard Larsen, Lene; Hedegaard Larsen, Birte; Birkelund, Regner

    2013-01-01

    and volunteered participation. Typically, the social interaction was experienced as giving and was referred to in positive terms but recurrently, the opposite was experienced too. The ambiguity of the relationship clearly emerged in all of the synthesized themes presented in this article. Implications...

  10. An ambiguous relationship

    DEFF Research Database (Denmark)

    Andersen, Lene Søndergaard; Larsen, Birte Hedegaard; Birkelund, Regner

    2013-01-01

    . Typically, the social interaction was experienced as giving and was referred to in positive terms but recurrently, the opposite was experienced too. The ambiguity of the relationship clearly emerged in all of the synthesized themes presented in this article. Implications for practice: Hospitalized patients...

  11. Creating Good Relationships: Responsiveness, Relationship Quality, and Interpersonal Goals

    OpenAIRE

    Canevello, Amy; Crocker, Jennifer

    2010-01-01

    Perceived partner responsiveness is a core feature of close, satisfying relationships. But how does responsiveness originate? Can people create relationships characterized by high responsiveness, and consequently, higher quality relationships? We suggest that goals contribute to cycles of responsiveness between people, improving both people’s relationship quality. The present studies examine 1) how interpersonal goals initiate responsiveness processes in close relationships, 2) the self-perpe...

  12. Efficiency droop in high-Al-content AlGaN/AlGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Tamulaitis, G.; Mickevicius, J.; Kazlauskas, K.; Zukauskas, A. [Institute of Applied Research and Department of Semiconductor Physics, Vilnius University, Sauletekio 9-III, 10222 Vilnius (Lithuania); Shur, M.S. [Department of ECE and CIE, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States); Yang, J.; Gaska, R. [Sensor Electronic Technology Inc., 1195 Atlas Road, Columbia, SC 29209 (United States)

    2011-07-15

    Excitation power density dependence of photoluminescence (PL) efficiency is studied in the temperature range from 8 to 300 K for AlGaN multiple quantum well structures containing quantum wells of different width. PL efficiency droop is observed and dependence of the droop effect on the well width and lattice temperature is discussed. Photoluminescence band shape reveals strong carrier heating. It is shown that the heating effect has a substantial influence on the photoluminescence efficiency droop, especially at low lattice temperatures. Fitting of the temperature dependence of the PL band width with that obtained by the Monte Carlo simulation of carrier (exciton) hopping via localized states shows that (i) the potential fluctuations can be fairly accurately described using a double-scaled potential profile model, (ii) the localization becomes stronger in narrower quantum wells. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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

    OpenAIRE

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

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure...

  14. Understanding the process of Repair in dissolving Business to Business Relationships: An SME perspective

    OpenAIRE

    Fleming, Deirdre

    2014-01-01

    Despite considerable research examining the dissolution of business to business (B2B) relationships, studies exploring the repair of these relationships have been insufficiently explored empirically. To date most B2B dissolution research has focussed attention on the reasons why relationships end (Farrelly, 2010; Pressey & Selassie, 2007; Hocutt, 1998; Halinen, 1997; Keaveney, 1995; Perrien, Paradis & Richard, 1995), or other influencing factors (Olkkonen & Tuominen, 2006; Wang et al, 2004; H...

  15. Relationship Marketing in Educational Services

    OpenAIRE

    Pariza - Manea Natalia

    2012-01-01

    This article aims to analyze the existence of relationship marketing in educational services. This type of marketing focuses on building a lasting relationship with the customer and continuous communication with it. Relationship marketing can focus on the university's relationship with the end consumer (companies that hire graduates) and other client organizations (schools, universities, research centers).

  16. Antecedents of Customer Relationship Termination

    DEFF Research Database (Denmark)

    Geersbro, Jens; Ritter, Thomas

    relationships as a managerial task. This paper contributes by (1) developing a conceptualization of relationship termination competence and (2) analyzing its antecedents. The empirical results identify termination acceptance, definition non-customers, organizational relationship termination routines......, and motivation as significant antecedents. Because of this, managers need to develop their organizations in order to use relationship termination as a vital strategy....

  17. Theologie als (herinterpretatie: Zesentwintig overwegingen

    Directory of Open Access Journals (Sweden)

    Gijsbert D.J. Dingemans

    2014-02-01

    Full Text Available Theology as (reinterpretation: Twenty-six considerations. The article consists of 26 points of reflection by means of which the nature of theological discourse is considered as a hermeneutical process. These indicators cover aspects such as the relationship between the natural sciences and religious thinking; hermeneutics; philosophy; ultimacy; symbolic meaningfulness; Old Testament roots; historical Jesus; Christological dogmatics; creation and Spirit; kenosis; and social concern. The article concludes in its last reflection with the claim that plurality in both religious discourse and ecclesiastical structures is the challenge for theology, so as to remain relevant in the present-day scientific discourse and religiosity and to be obedient to the vocation of Jesus.

  18. 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.

  19. Kayırmacılığın Çalışanlar Üzerine Etkileri İle İnsan Kaynakları Uygulamaları İlişkisi: Türk Kamu Bankalarına Yönelik Bir Araştırma / The Relationship Between the Effects of Nepotism on the Employees and Human Resource Practices: A Research on Turkish Publ

    OpenAIRE

    BÜTE, Mustafa

    2012-01-01

    Özet: Bu araştırmanın iki temel amacı vardır. Birincisi, Türk kamu bankalarında kayırmacılığınçalışanlar üzerine etkilerini incelemektir. İkinci amacı ise, kamu bankalarındakiinsan kaynakları uygulamaları ile kayırmacılık etkileri arasındaki ilişkiyi incelemektir.Veriler anket yardımı ile toplanmıştır. Araştırma, Ankara'da faaliyet gösterenkamu bankalarında çalışan 243 çalışan üzerinde gerçekleştirilmiştir.Bu araştırmanın sonuçlarına...

  20. Entrevista al narrador Tommaso Pincio

    Directory of Open Access Journals (Sweden)

    Franco Zangrilli

    2016-07-01

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

  1. Fabrication of TiAl3 coating on TiAl-based alloy by Al electrodeposition from dimethylsulfone bath and subsequent annealing

    OpenAIRE

    Miyake, Masao; Tajikara, Seiya; Hirato, Tetsuji

    2011-01-01

    TiAl3 coating was formed on TiAl alloy by Al electrodeposition from a dimethylsulfone (DMSO2) bath and subsequent annealing. Before the Al electrodeposition, anodic dissolution of TiAl substrate in the DMSO2 bath was conducted to remove the surface oxide layer of the TiAl substrate. By performing the Al electrodeposition immediately after the anodic dissolution, uniform Al films adherent to the TiAl substrate could be obtained. Annealing at 650–1000 °C yielded a single TiAl3 layer or two laye...

  2. Composition-Structure-Property Relationships in Boroaluminosilicate Glasses

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Potuzak, M.; Mauro, J.C.;

    2012-01-01

    The complicated structural speciation in boroaluminosilicate glasses leads to a mixed network former effect yielding nonlinear variation in many macroscopic properties as a function of chemical composition. Here we study the composition–structure–property relationships in a series of sodium...... boroaluminosilicate glasses from peralkaline to peraluminous compositions by substituting Al2O3 for SiO2. Our results reveal a pronounced change in all the measured physical properties (density, elastic moduli, hardness, glass transition temperature, and liquid fragility) around [Al2O3]–[Na2O]=0. The structural...

  3. 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.

  4. Electron channelling enhanced microanalysis on Ni-Al-Mn and Al-Mn-Si

    International Nuclear Information System (INIS)

    Atom location by channelling enhanced microanalysis (ALCHEMI) was performed for Ni-Al-Mn compounds and Al-Mn-Si quasicrystals. For Ni75Al25-xMnx (x=5,9) with the L12-type structure, an occupation fraction of Mn atoms at the Ni site was quantitatively determined using planar channelling conditions. The occupation fraction increases with the Mn concentration or by quenching the compound from high temperature. In quasicrystals of Al74Mn20Si6 and Al68Mn20Ru8Si4, axial channelling conditions were used to locate Si and Ru, respectively. It was shown that Si atoms occupy the Al site in Al74Mn20Si6 whereas Ru atoms occupy the site different from that of Al in Al68Mn20Ru8Si4. (author)

  5. A New Phase in ALS Research.

    Science.gov (United States)

    Chong, P Andrew; Forman-Kay, Julie D

    2016-09-01

    In this issue of Structure, Conicella et al. (2016) present evidence that the low complexity C-terminal region of TDP-43 undergoes liquid-liquid phase separation. ALS-associated mutations alter this phase separation process, providing a possible mechanism for the pathology caused by these TDP-43 mutations. The work is strongly supportive of toxic loss of RNA processing function in ALS. PMID:27602988

  6. The wobbler mouse, an ALS animal model

    OpenAIRE

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

    2013-01-01

    This review article is focused on the research progress made utilizing the wobbler mouse as animal model for human motor neuron diseases, especially the amyotrophic lateral sclerosis (ALS). The wobbler mouse develops progressive degeneration of upper and lower motor neurons and shows striking similarities to ALS. The cellular effects of the wobbler mutation, cellular transport defects, neurofilament aggregation, neuronal hyperexcitability and neuroinflammation closely resemble human ALS. Now,...

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

    Institute of Scientific and Technical Information of China (English)

    Chen Tijun; Li Jian; Hao Yuan

    2009-01-01

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

  8. Relationship Maintenance on Facebook: Development of a Measure, Relationship to General Maintenance, and Relationship Satisfaction

    Science.gov (United States)

    Dainton, Marianne

    2013-01-01

    Previous research indicates that the primary reason college students use Facebook is for relationship maintenance. The present study sought to determine the relationship between Facebook maintenance and general maintenance efforts in college student romantic relationships, as well as the impacts of such behaviors on the relationship. Survey data…

  9. Groente- en fruitafvallen als veevoer : inventarisatie

    NARCIS (Netherlands)

    Vries, de A.

    1982-01-01

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

  10. Genetics of Familial and Sporadic ALS

    Science.gov (United States)

    2016-03-21

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

  11. Growth of CdTe: Al films

    International Nuclear Information System (INIS)

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

  12. Establishing effective working relationships.

    Science.gov (United States)

    Houghton, Trish

    2016-02-24

    This article, the second in a series of 11, provides support and offers advice to new and existing mentors and practice teachers to enable them to progress in their role and develop a portfolio of evidence. In particular, the article discusses how to establish effective working relationships and emphasises the importance of the student-mentor or student-practice teacher relationship. It examines the essential qualities, attributes and characteristics of an effective mentor or practice teacher. The article provides learning activities and suggests ways in which mentors and practice teachers can undertake various self-assessments, enabling them to gather relevant evidence to demonstrate how they can meet and maintain the requirements for these roles as stipulated by the Nursing and Midwifery Council.

  13. Probability distribution relationships

    Directory of Open Access Journals (Sweden)

    Yousry Abdelkader

    2013-05-01

    Full Text Available In this paper, we are interesting to show the most famous distributions and their relations to the other distributions in collected diagrams. Four diagrams are sketched as networks. The first one is concerned to the continuous distributions and their relations. The second one presents the discrete distributions. The third diagram is depicted the famous limiting distributions. Finally, the Balakrishnan skew-normal density and its relationship with the other distributions are shown in the fourth diagram.

  14. Customer Relationship Management

    OpenAIRE

    Kovshevnaya, Valentina

    2015-01-01

    This diploma thesis deals with Customer Relationship Management (CRM). The main purpose of the diploma thesis is to explore CRM theoretically, which means to explain its fundamentals, principals and goals, identify CRM processes and investigate their flow in each of the phases of CRM, to explain CRM technology and show that the implementation of CRM in organization is demanding on human resourses. The purpose is achieved by systematisation of the theoretical knowledge about CRM using a method...

  15. Relationship quality in Europe

    OpenAIRE

    Wiik, Kenneth Aarskaug; Lappegård, Trude; Keizer, Renske

    2010-01-01

    In this study, we utilize data from the first wave of the Generations and Gender Surveys to investigate relationship quality among currently married and cohabiting individuals aged 18 to 55 (N = 41, 666) in eight European countries (Bulgaria, France, Germany, Hungary, Norway, Romania, Russia, and the Netherlands). Controlling for a range of characteristics of respondents and their partners, the analyses show that cohabitors in general more often have breakup plans and are less satisfied than ...

  16. Meaning in couples relationships.

    OpenAIRE

    Rodrigues T.F.

    2014-01-01

    Based on psycholinguistics and L. Vygotsky’s (2007) theories on sign, meaning and sense categories, as later discussed by A. Leontiev (2004, 2009), we present a case study that focuses on the intricacies of a love relationship for a woman who remained in a painful marriage. Interview material is presented in a Relational-Historical Psychology theoretical framework to provide central categories of meaning and sense. This is understood as a privileged method for apprehending the uniqueness of a...

  17. MEANING IN COUPLES RELATIONSHIPS

    OpenAIRE

    Rodrigues, Tâmara

    2014-01-01

    Based on psycholinguistics and L. Vygotsky’s (2007) theories on sign, meaning and sense categories, as later discussed by A. Leontiev (2004, 2009), we present a case study that focuses on the intricacies of a love relationship for a woman who remained in a painful marriage. Interview material is presented in a Relational-Historical Psychology theoretical framework to provide central categories of meaning and sense. This is understood as a privileged method for apprehending the uniqueness of a...

  18. CUSTOMER RELATIONSHIP MANAGEMENT

    OpenAIRE

    Gray, Paul; Byun, Jongbok

    2008-01-01

    In order to maintain in a market economy with the competition becoming increasingly tough, with consumer preferences and demands more sophisticated and diverse, a company must manage in the best possible way the relations with the existing and potential customers to know their preferences, attitudes, purchasing behaviour, motivations, in order to attract the proper clients for their company products. These goals may be achieved by implementing a strategy called “Customer Relationship Manageme...

  19. Influence of Al Composition on the Microstructure of B Alloyed Ni3Al Synthesized under Compression

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It was shown by TEM and X-ray analysis that Ni3Al is the mainphase of the intermetallic synthesized under compression from the powder mixture of Ni with Al alloyed by B. The Ni3B is a secondary phase. The value of the lattice parameter of the intermetallic Ni3Al with and without B increases when the concentration of Al increases. The increase in Al concentration from 23.5 to 25.0 in the initial powder mixture leads to decreasing the solubility of B in the Ni3Al phase.

  20. Magnetic Properties and Activity of Pt-Er/γ-Al2O3 Catalysts

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A series of Pt-Er/γ-Al2O3 catalysts containing 0.5%(mass fraction) platinum and 0.05%-1.5% Er were prepared by impregnation of γ-Al2O3 supported with different concentrations of erbium chloride solution. The surface properties of the catalysts were studied by methods of temperature programmed reduction and temperature programmed desorption. The magnetic behavior of Pt-Er-γ-Al2O3 catalysts were studied with a Faraday magnetic balance and the results show that the addition of Er can affect the surface properties, the catalytic activities, and magnetic behavior of the reforming catalysts. It is found that there is a corresponding relationship between the susceptibility and selectivity of Pt-Er-γ-Al2O3 catalysts. The experimental results show that Er plays the role of electron promoter.

  1. The stability of B2 compounds in Ti-modified Nb-Al alloys

    International Nuclear Information System (INIS)

    It has been found that additions of Ti to Nb3Al results in the formation of phases with the B2 crystal structure in as-cast samples. The microstructure and phase stability of two alloys, namely Nb-15Al-10Ti and Nb-15Al-40Ti (in at.%), have been studied. Heat-treatment of the Nb-15Al-10Ti alloy at 1,100 C results in the precipitation of an A15 phase in the B2 matrix. A particular orientation relationship exists between the two phases. Heat-treatment above 1,600 C results in the dissolution of the second phase. The ALCHEMI technique has been employed to assess qualitatively the distribution of atom types over the two sublattices of the B2 compound

  2. The Effect of Si Morphology on Machinability of Al-Si Alloys

    Directory of Open Access Journals (Sweden)

    Muhammet Uludağ

    2015-12-01

    Full Text Available Many of the cast parts require some sort of machining like milling, drilling to be used as a finished product. In order to improve the wear properties of Al alloys, Si is added. The solubility of Si in Al is quite low and it has a crystallite type structure. It behaves as particulate metal matrix composite which makes it an attractive element. Thus, the wear and machinability properties of these type of alloys depend on the morphology of Si in the matrix. In this work, Sr was added to alter the morphology of Si in Al-7Si and Al-12Si. Cylindrical shaped samples were cast and machinability characteristics of Sr addition was studied. The relationship between microstructure and machinability was evaluated.

  3. Response to Signorovitch et al.

    Science.gov (United States)

    Flot, Jean-François; Debortoli, Nicolas; Hallet, Bernard; Van Doninck, Karine

    2016-08-22

    Signorovitch et al.[1] comment that an Oenothera-like meiosis [2] could produce a pattern similar to what we observed in our study of natural isolates of the bdelloid rotifer Adineta vaga, which we attributed to horizontal gene transfers (HGTs) [3]. Indeed, our HGT hypothesis appears at first sight difficult to conciliate with their observation of a congruent pattern of allele sharing at four large loci possibly located on different chromosomes [4]. However, one might imagine conditions under which massive horizontal gene transfer between bdelloid individuals could produce such a pattern, notably if the individuals involved had previously lost most of their heterozygosity because of their exposure to frequent desiccation (which produces DNA double-strand breaks [5]). In the published A. vaga genome the loss of heterozygosity due to large-scale gene conversion events or break-induced replication covers only about 10% of the genome [6], but this percentage may be much higher in environmental isolates that often experience dessication. Besides, if an Oenothera-like mode of meiosis occurs in bdelloids frequently enough to be detected in a single sampling of 29 individuals (as in [4]), one would expect males and meiosis to be observed at least occasionally, and instances of congruent allele sharing across loci should turn up frequently in genetic surveys. This was not the case in [3]: among the 82 A. vaga individuals sequenced for four nuclear markers, no trio of individuals presented congruent patterns of shared sequences at different loci. For these reasons, and in the absence of any direct evidence for an Oenothera-like meiosis in bdelloids, we still consider inter-bdelloid HGTs a more parsimonious explanation for our results. PMID:27554651

  4. Predicting the Extent of Inundation due to Sea-Level Rise: Al Hamra Development, Ras Al Khaimah, UAE. A Pilot Project

    Directory of Open Access Journals (Sweden)

    Arthur Robert M.

    2016-06-01

    Full Text Available As new information is received, predictions of sea-level rise resulting from global warming continue to be revised upwards. Measurements indicate that the rise in sea-level is continuing at, or close to, the worst case forecasts (Kellet et al. 2014. Coastal areas are coming under increasing risk of inundation and flooding as storms are predicted to increase in frequency and severity, adding to the risk of inundation due to higher sea levels. Stakeholders, government agencies, developers and land owners require accurate, up to date information to be able to protect coastal areas. Geographic Information Systems (GIS along with accurate remote sensing technologies such as LiDAR provides the best means for delivering this information. Using these technologies, this paper predicts the risk posed to a large multi-use development in the emirate of Ras Al Khaimah, UAE. This development, Al Hamra Village, is situated on the coast of the Arabian Gulf. Al Hamra’s physical relationship to the Gulf is in common with other developments in Ras Al Khaimah in its and for this reason has been used as a pilot project. The resulting GIS model shows that Al Hamra is indeed at risk from predicted flood events. How this information can be used as a planning tool for numerous strategies is discussed in this paper.

  5. Microstructure characteristics and compressive properties of NiAl-based multiphase alloy during heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, L.Y., E-mail: lysheng@yeah.net [Peking University, Beijing 100871 (China); PKU-HKUST ShenZhen-Hong Kong Institution, Shenzhen 518057 (China); Xie, Y. [Hunan Electric Power Test and Research Institute, Changsha 410007 (China); Xi, T.F. [Peking University, Beijing 100871 (China); Guo, J.T. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zheng, Y.F. [Peking University, Beijing 100871 (China); Ye, H.Q. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2011-11-15

    Highlights: {yields} The {alpha}-Cr, {sigma} and {mu} phases precipitate and form into network in as cast alloy. {yields} Rapid and intermediate cooling rate after solution treatment break the precipitates network; the lower cooling rate results in some {alpha}-Cr and Ni{sub 3}Al precipitates. {yields} Short-term aging results in massive Ni{sub 3}Al lathes and {alpha}-Cr particles, but long-term aging treatment coarsens the globule-shaped {alpha}-Cr particle and decreases the lath-shaped Ni{sub 3}Al, {mu} and {sigma} phase. {yields} The solid solution with short-term aging treatment improves mechanical properties of the alloy significantly. - Abstract: The alloy of Ni-Al26-Cr15-Co6-Ti3-Mo2-Nb0.5-Ho0.1 (at.%) was heat-treated and studied by microstructure examination and compressive test. The results reveal that in the as-cast alloy, {alpha}-Cr, {sigma} and {mu} phases are segregated along the NiAl phase boundary and form into network. Small Ni{sub 2}AlTi, Cr{sub 2}Nb and Ni{sub 2}Al{sub 3}Ho particles precipitate at NiAl grain boundary. The subsequent solid solution treatment with rapid and intermediate cooling rate transforms the net-like precipitating phases into discontinuous ones, but the rapid cooling leads to micro-cracks along phase boundary. However the lower cooling rate results in spherical {alpha}-Cr particle and needle-like Ni{sub 3}Al phase in NiAl matrix. The short-term aging after solid solution treatment promotes the coarsening of Ni{sub 3}Al lathes and {alpha}-Cr particles, and an orientation relationship of [001-bar]{sub {beta}}||[1-bar 10]{sub {lambda}{sup '}} and (1 1 0){sub {beta}}||(1 1 1){sub {gamma}'} is found between lath-shaped Ni{sub 3}Al phase and NiAl matrix. In addition, the {mu} phases are substituted by {sigma} and some Cr{sub 3}Ni{sub 2} phases. The long-term aging treatment reduces Ni{sub 3}Al, {sigma} and {mu} phases and coarsens the {alpha}-Cr phase further. The solid solution treatment and short-term aging improve the

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

    Science.gov (United States)

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

    2016-01-01

    Al/AlOx/Al Josephson junctions are the building blocks of a wide range of superconducting quantum devices that are key elements for quantum computers, extremely sensitive magnetometers and radiation detectors. The properties of the junctions and the superconducting quantum devices are determined by the atomic structure of the tunnel barrier. The nanoscale dimension and disordered nature of the barrier oxide have been challenges for the direct experimental investigation of the atomic structure of the tunnel barrier. Here we show that the miniaturized dimension of the barrier and the interfacial interaction between crystalline Al and amorphous AlOx give rise to oxygen deficiency at the metal/oxide interfaces. In the interior of the barrier, the oxide resembles the atomic structure of bulk aluminium oxide. Atomic defects such as oxygen vacancies at the interfaces can be the origin of the two-level systems and contribute to decoherence and noise in superconducting quantum circuits. PMID:27403611

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

    Science.gov (United States)

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

    2016-07-01

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

  8. Kritik al-Ghazali terhadap Kekekalan Alam

    Directory of Open Access Journals (Sweden)

    Sahidi Mustafa

    2015-12-01

    Full Text Available The concept of the creation of universe offered by Neo-Platonism philosopher such as al-Kindi, al-Farabi, and Ibnu Sina are philosophical concept existed and came as an early moment of development of Islamic philosophy interrelated to God, ultimately about his Existence and Characteristics. One of the topics is how God created the universe. According to al-Farabi and Ibnu Sina, God created this universe by way of emanation in order to prevent Himself from the new attitudes. Consequently, universe has eternal feature (qadim as God as well, in the case of everything overflowed from qadim is also qadim. Al-Ghazali refuted this theory because it contradicted with al Qur’an’s thought which clearly explained that God created the entire universe. The universe should not qadim and it means that God existed in the first, and then created universe later as we know today. On the contrary, in the view of Muslim philosopher, the universe should be qadim because God created it from all eternity. For them, it is impossible that God existed by Himself without any creation before. God, according to them is impossible to be changed, so that is impossible as well if God changed from did not create yet before and then creates. Al-Ghazali persistently opposed the concept of eternity. Al Ghazali saw if this universe is qadim so it is impossible that universe created by God. The concept of qadim will led to the conclusion that universe born by itself, it was not created by God. This critique has been written by al-Ghazali in Tahafut al-Falasifah. This paper will present the concept of eternity which was discussed by al-Farabi and Ibn Sina and al Ghazali’s critique toward it as well.

  9. Untersuchung der Nitridierung V/Al-intermetallischer Phasen

    OpenAIRE

    Lewalter, Hartmut Berthold

    2004-01-01

    Schichten V/Al-Intermetallischer Phasen und Schichten aus V(Al) (Schichtdicken 150- 300 nm) wurden durch Interdiffusion von V/Al- und V5Al8/V-Mehrfachschichten bei 400-800°C im Vakuum bei 3 x 10-8 mbar hergestellt. Des Weiteren wurden V5Al8-Schichten durch Sputtern einer V5Al8-Legierung erzeugt. Die Gesamtstöchiometrie der Schichten lag zwischen Al0,86V0,14 und Al0,19V0,81. Als Substrat dienten einkristalline (012) Saphirwafer. Die V/Al-Intermetallischen Phasen und V(Al) wurden im RTP-System ...

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

    Science.gov (United States)

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

    2016-10-01

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

  11. The theory of the moon in the al-Zij al-Kamil fi-l-taalim of Ibn al-Ha'im

    OpenAIRE

    Puig i Tàrrech, Roser

    2000-01-01

    Al the beginning of Ihe thirteenth cenrury (60tH I 1204-1205) Abli Muhammad Abd al-Haqq al-Ghafiqi al-lshbiIi known as Ibn al-Ha'im composed his work entitled al-Zi] al-Kamil fi-l-Taalim in honour of the Caliph Abu Abd Allah Muhammad al-Nasir (who reigned from 1199- 1213). All we know of lbn al-Ha'im's live is that he came from Seville and that he appears to have worked in North Africa.

  12. Effects of alloying elements on elastic properties of Al by first-principles calculations

    Directory of Open Access Journals (Sweden)

    Wang J.

    2014-01-01

    Full Text Available The effects of alloying elements (Co, Cu, Fe, Ge, Hf, Mg, Mn, Ni, Si, Sr, Ti, V, Y, Zn, and Zr on elastic properties of Al have been investigated using first-principles calculations within the generalized gradient approximation. A supercell consisting of 31 Al atoms and one solute atom is used. A good agreement is obtained between calculated and available experimental data. Lattice parameters of the studied Al alloys are found to be depended on atomic radii of solute atoms. The elastic properties of polycrystalline aggregates including bulk modulus (B, shear modulus (G, Young’s modulus (E, and the B/G ratio are also determined based on the calculated elastic constants (cij’s. It is found that the bulk modulus of Al alloys decreases with increasing volume due to the addition of alloying elements and the bulk modulus is also related to the total molar volume (Vm and electron density (nAl31x with the relationship of nAl31x=1.0594+0.0207√B/Vm. These results are of relevance to tailor the properties of Al alloys.

  13. Pinhole Effect on the Melting Behavior of Ag@Al2O3 SERS Substrates.

    Science.gov (United States)

    Ma, Lingwei; Huang, Yu; Hou, Mengjing; Li, Jianghao; Zhang, Zhengjun

    2016-12-01

    High-temperature surface-enhanced Raman scattering (SERS) sensing is significant for practical detections, and pinhole-containing (PC) metal@oxide structures possessing both enhanced thermal stability and superior SERS sensitivity are served as promising SERS sensors at extreme sensing conditions. Through tuning the Al2O3 precursors' exposure time during atomic layer deposition (ALD), Al2O3 shells with different amount of pinholes were covered over Ag nanorods (Ag NRs). By virtue of these unique PC Ag@Al2O3 nanostructures, herein we provide an excellent platform to investigate the relationship between the pinhole rate of Al2O3 shells and the melting behavior, high-temperature SERS performances of these core-shell nanostructures. Pinhole effect on the melting procedures of PC Ag@Al2O3 substrates was characterized in situ via their reflectivity variations during heating, and the specific melting point was quantitatively estimated. It is found that the melting point of PC Ag@Al2O3 raised along with the decrement of pinhole rate, and substrates with less pinholes exhibited better thermal stability but sacrificed SERS efficiency. This work achieved highly reliable and precise control of the pinholes over Al2O3 shells, offering sensitive SERS substrates with intensified thermal stability and superior SERS performances at extreme sensing conditions. PMID:27033846

  14. Mechanical and microstructural characterization of dispersion strengthened Al-C system nanocomposites

    International Nuclear Information System (INIS)

    Al and different amounts of C and C-Cu mixtures were used to produce Al-C and Al-C-Cu powder samples by mechanical milling. Microhardness tests were carried out to evaluate the mechanical properties of the nanocomposites in the as-milled condition. In general, the measured values were considerably higher than pure Al. In order to determine the causes of this hardening, the crystallite size and dislocation density were measured by means of X-ray analyses coupled with a convolutional multiple whole profile (CMWP) fitting program and a comparison with atomic force microscopy (AFM) observations. In Al-C samples, the hardening is mainly due to the decrease of the crystallite size, however for the Al-C-Cu, an additional strengthening mechanism appears and it seems that it is due by a dispersion of graphite nanoparticles in the Al matrix. The strengthening contributions of dislocation density, crystallite size and particle dispersion were modeled by superposing of every single contribution to strengthening (via hardness analyses). We found a direct relationship between the mechanical properties and the nominal amount of C-Cu, where Cu apparently acts as C nanoparticles integration and dispersion agent.

  15. Microstructure of A γ-α2-β Ti-Al alloy containing iron and vanadium

    International Nuclear Information System (INIS)

    Ordered β-phase (B2 CsCl structure) has been identified in a Ti-45.5 at.% Al-1.6 at.% Fe-1.1 at.% V-0.7 at.% B alloy being developed for high temperature applications. Selected area electron diffraction has been used to identify the orientation relationships and interface planes of the β-phase with the bulk γ-TiAl and α2-Ti3Al phases. Energy dispersive X-ray spectroscopy indicates that the β-phase has approximately the same Ti/Al ratio as the α2-Ti3Al phase, and is stabilized within the microstructure by Fe and V. Channeling enhanced microanalysis studies (ALCHEMI) show that the Fe and V both occupy the same sublattice as the Al atoms in the cubic β-phase structure, and that Fe occupies the Al sites in the γ-phase. Fe and V are concentrated in the β-phase, which effectively getters these dopants from the γ and α2 phases. Titanium ferride precipitates, probably FeTi, have been observed within the β-phase

  16. Geluk als onderwerp van wetenschappelijk onderzoek

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    1970-01-01

    textabstractAbstract in Dutch: Geluk wordt gedefinieerd als overwegende tevredenheid met het leven als geheel. Dit artikel geeft een overzicht van het onderzoek naar dat verschijnsel. Geluk blijkt deels afhankelijk van persoonlijke eigenschappen. Zo blijkt ondermeer dat gelukkige mensen over het alg

  17. 75 FR 62858 - United States, et al.

    Science.gov (United States)

    2010-10-13

    ... Antitrust Division United States, et al. v. American Express Company, et al.; Proposed Final Judgment and... been filed with the United States District Court for the Eastern District of New York in United States..., 2010, the United States and seven States filed a Complaint alleging that certain rules, policies,...

  18. Als je vrienden hebt dan win je

    NARCIS (Netherlands)

    Effing, R. (Robin); Huibers, T. (Theo); Krosse, de L. (Luc)

    2010-01-01

    Als je wint, heb je vrienden’ is een Nederlandse klassieker van Herman Brood en Henny Vrienten. Hiermee werd de gevoelige snaar bloot gelegd dat pas als je hebt gewonnen je vrienden hebt. Rijen dik, echte vrienden. In de politiek werkt het andersom; je moet vrienden (stemmen) hebben, ve

  19. Diana Al-Hadid: Identity and Heritage

    Science.gov (United States)

    Jungerberg, Tom; Smith, Anna; Borsh, Colleen

    2012-01-01

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

  20. Kus on al-Zarqawi? / Aadu Hiietamm

    Index Scriptorium Estoniae

    Hiietamm, Aadu, 1954-

    2005-01-01

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

  1. Al-Farabi dan Filsafat Kenabian

    Directory of Open Access Journals (Sweden)

    Qosim Nursheha Dzulhadi

    2014-03-01

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

  2. The role of inclusions in ALS pathogenesis

    NARCIS (Netherlands)

    V. van Dis (Vera)

    2012-01-01

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

  3. TIGER/Line Shapefile, 2013, county, Colbert County, AL, Current Address Ranges Relationship File

    Data.gov (United States)

    US Census Bureau, Department of Commerce — The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master...

  4. 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...

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Benedikt Weiler

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    A.M Ismatulloh

    2012-12-01

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

  8. Thermoluminescence properties of AlN ceramics

    DEFF Research Database (Denmark)

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

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, D; Heilmaier, M; Saage, H [Otto von Guericke University Magdeburg, Institute for Materials and Joining Technology, PO Box 4120, D-39016 Magdeburg (Germany); Aguilar, J; Schmitz, G J; Drevermann, A [ACCESS e.V., Intzestrasse 5, D-52072 Aachen (Germany); Palm, M; Stein, F; Engberding, N [Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, D-40237 Duesseldorf (Germany); Kelm, K; Irsen, S, E-mail: daniel.sturm@ovgu.d [Stiftung caesar, Electron Microscopy, Ludwig-Erhard-Allee 2, D-53175 Bonn (Germany)

    2010-07-01

    Compared to Ti-rich {gamma}-TiAl-based alloys Al-rich Ti-Al alloys offer an additional reduction of in density and a better oxidation resistance which are both due to the increased Al content. Polycrystalline material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical, scanning and transmission electron microscopy and XRD analyses. The high temperature creep of two binary alloys, namely Al{sub 60}Ti{sub 40} and Al{sub 62}Ti{sub 38} was comparatively assessed with compression tests at constant true stress in a temperature range between 1173 and 1323 K in air. The alloys were tested in the cast condition (containing various amounts of the metastable phases Al{sub 5}Ti{sub 3} and h-Al{sub 2}Ti) and after annealing at 1223 K for 200 h which produced (thermodynamically stable) lamellar {gamma}-TiAl + r-Al{sub 2}Ti microstructures. In general, already the as-cast alloys exhibit a reasonable creep resistance at 1173 K. Compared with Al{sub 60}Ti{sub 40}, both, the as-cast and the annealed Al{sub 62}Ti{sub 38} alloy exhibit better creep resistance up to 1323 K which can be rationalized by the reduced lamella spacing. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded apparent activation energies for creep of Q = 430 kJ/mol for the annealed Al{sub 60}Ti{sub 40} alloy and of Q = 383 kJ/mol for the annealed Al{sub 62}Ti{sub 38} material. The latter coincides well with that of Al diffusion in {gamma}-TiAl, whereas the former can be rationalized by the instability of the microstructure containing metastable phases.

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

    OpenAIRE

    Imriyanti Imriyanti

    2014-01-01

    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 want...

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

    Science.gov (United States)

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

    1998-01-01

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

  12. Industrial relationship marketing

    Energy Technology Data Exchange (ETDEWEB)

    Schellinck, T.; Marriott, H. [Focal Research Consultants Ltd., Halifax, NS (Canada)

    1995-11-01

    A survey was conducted to establish a process for analyzing electrical utility/industrial customer relations. The information was used to help the utility companies in decision making and customer-oriented action. Data was collected by mail with two surveys. One hundred and thirteen companies were used in the development and analysis of key customer indicators. Factors which influence the relationship measures of customer satisfaction and customer commitment were identified. The report can be used as a basis on which utilities can build customer information for decision making in the development of marketing strategy. tabs., figs.

  13. Library/vendor relationships

    CERN Document Server

    Brooks, Sam

    2014-01-01

    A view of the mutual dependence between libraries and vendorsAs technology advances, libraries are forced to reach beyond their own resources to find effective ways to maintain accuracy and superior service levels. Vendors provide databases and integrated library systems that perform those functions for profit. Library/Vendor Relationships examines the increasing cooperation in which libraries find they must participate in, and vice versa, with the vendors that provide system infrastructure and software. Expert contributors provide insights from all sides of this unique collaboration, offering

  14. Metalogenia asociada a las ofiolitas y al arco de islas del cretácico del nordeste de Cuba

    Directory of Open Access Journals (Sweden)

    Roberto Díaz-Martínez

    2005-03-01

    Full Text Available Los estudios metalogénicos revelaron tres distritos mineros con yacimientos de cromitas metalúrgicas y refractarias, con o sin platinoides, asociados a la Faja Ofiolítica Mayarí-Baracoa y tres sectores con mineralizaciones de oro y plata, cobre-plomo-zinc y cupro-pirítica con oro refractarias, se ubican estructuralmente en la Zona de Transición Manto-Corteza. Los cuerpos de cromititas del distrito Moa-Baracoa, ricos en cromitas son cúmulos ultramáficos y cuerpos de gabroides. Las cromititas del distrito Mayarí están constituidas por cuerpos de cromitas metalúrgicas ubicadas estructuralmente en los niveles más profundos del manto superior; éstos se asocian a las harzburgitas del complejo de tectonitas. Los cuerpos de cromititas del distrito Sagua de Tánamo poseen cromitas de ambos tipos. El Arco de Isla del Cretácico posee una metalogenia muy variada, caracterizada por el predominio de manifestaciones de oro y plata, cobre-plomo-zinc y cupro-pirítica. Estas se asocian a diabasas, andesitas y basaltos toleíticos de las zonas de retroarco y de antearco; las de retroarco poseen tendencia boninítica. La metalogenia exógena de la región se caracteriza por la abundancia de placeres marino-costeros, eluviales y aluviales, con minerales de interés económico tales como magnetita, cromita, ilmenita, oro y minerales del grupo del platino.

  15. Composition dependence of viscosity for Al(1-x)Mgx(0≤x≤0.10) alloys

    Institute of Scientific and Technical Information of China (English)

    WANG YuQing; WU YuQin; BIAN XiuFang

    2007-01-01

    Viscosities of molten Al(1-x)Mgx (0≤x≤0.10) alloys have been measured in the temperature range of 973K-1173 K by a torsional oscillation cup method. The viscosity dependence on temperature for Al(1-x)Mgx (0≤x≤0.10) melts obeys Arrhenius equation. The viscosity increases with increasing magnesium concentration in the investigated system. There is an important relationship between viscosity and its glass-forming ability for metallic melt.

  16. Relationship Marketing in Professional Services

    OpenAIRE

    Bains, Nimrita

    2005-01-01

    This research examines relationship marketing within professional services in general and architectural services in particular. The architectural industry in professional services has received little attention from researchers and represents a significant gap in the marketing literature on relationship marketing. Architectural services is an important context for researching relationships as the projects tend to extend over a long period of time and the architectural firm-client relationships...

  17. Parental Relationships in Fragile Families

    OpenAIRE

    McLanahan, Sara; Beck, Audrey N.

    2010-01-01

    As nonmarital childbearing escalated in the United States over the past half century, fragile families—defined as unmarried couples with children—drew increased interest from researchers and policy makers. Sara McLanahan and Audrey Beck discuss four aspects of parental relationships in these families: the quality of parents’ intimate relationship, the stability of that relationship, the quality of the co-parenting relationship among parents who live apart, and nonresident fathers’ involvement...

  18. Interpersonal relationships in early adulthood

    OpenAIRE

    Kočevar, Zala

    2014-01-01

    Interpersonal relationships in early adulthood, in people aged 25 to 30 vary considerably among individuals. Some place emphasis on partnership, and others on relations with friends. Even the relationship with parents and siblings are experienced by young adults in a variety of ways. Some have frequent and regular contact with their parents while some no longer have any relationship with their parents. These are two frequent situations hiding much more in between. Relationships are complex an...

  19. An Examination of the Relationship between Symptoms of Attention-Deficit/Hyperactivity Disorder and Symptoms of Anxiety in Children

    Science.gov (United States)

    Lipson, Stacey R.

    2012-01-01

    Numerous studies have found significant comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and anxiety disorders in children (e.g., Bauermeister et al., 2007; Busch et al., 2002), but limited research has examined factors that may underlie or explain this relationship (e.g., Lilienfeld, 2003; Baldwin & Dadds, 2008). This study…

  20. 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. PMID:27423564

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

    Science.gov (United States)

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

    2016-08-15

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

  2. THE IMPACT OF RELATIONSHIP QUALITY ON INCREASED ELECTRONIC COOPERATIVE RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    Ying-Pin Yeh

    2013-12-01

    Full Text Available The increased electronic cooperative relationships of retailers and their opinions regarding focal firms are important factors in enhancing the value-added relationships between supplier and retailer. The principal purpose of this study is to organize and analyze the major factors affecting the electronic cooperative relationships between supplier and retailer. After reviewing the relevant literature, we integrate three constructs to identify factors affecting retailer willingness and apply an electronic exchange platform to increase cooperative relationships with their product suppliers. This study presents nine hypotheses based on data collected through a questionnaire survey of retailers in the Taiwanese automobile industry. This study uses a structural equation model to test the hypotheses using data from the respondents. Results show that relationship commitment is directly and positively related to increased electronic cooperative relationships, and increased electronic cooperative relationships are indirectly and positively related to trust, satisfaction, perceived service characteristics, coordination, and perceived adaptation.

  3. Interfacial reactions in Al/Ni multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, F.; Greer, A.L. [Cambridge Univ. (United Kingdom). Dept. of Metallurgy and Materials Science

    1998-08-01

    In thin-film multilayers, the reactions at the interfaces can proceed quite differently from those in bulk samples because of the short diffusion distances involved. In the present work Al/Ni multilayers have been made by DC magnetron sputtering. The initial Ni and Al layers have strong (111) texture. The reactions taking place have been studied in relation to the layer thickness and film structure (grain size and texture). Also multilayers have been made with alloy layers Al/Ni(Al). Typically, differential scanning calorimetry shows a sequence of reactions on heating. X-ray diffraction, including texture goniometry, has been used to identify the compounds produced. In common with earlier work, it is found that Al{sub 3}Ni is the first phase to form, but the present results differ from those reported previously in that the Al{sub 3}Ni{sub 2} phase is not formed in the course of phase evolution. The difference from the earlier results is attributed to the sharper texture in the films in the present work. Thus it is concluded that for Al/Ni multilayers, reaction sequences can be affected by crystallographic orientation, as well as other factors. (orig.) 13 refs.

  4. Magnetism in bcc Fe-Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Elzain, M.E. [Sultan Qaboos Univ., Al-Khod (Oman). Dept. of Phys.; Yousif, A.A. [Sultan Qaboos Univ., Al-Khod (Oman). Dept. of Phys.

    1994-11-01

    The magnetic moment {mu}, hyperfine field B{sub hf} and isomer shift IS at the Fe site in bcc Fe-Al alloys were calculated from first principle. Contrary to the belief that Al atoms reside in the iron lattice as magnetic holes, it was found that the local magnetic moment of Fe is decreased when Al is at a nearest neighbour site (NN), while it increases if Al is at a next-nearest neighbour site (NNN). Consequently, the average {mu} per Fe atom was found to be, initially, independent of Al content. Assuming a linear dependence of {mu}{sub Fe} on the number of Al atoms at NN and NNN sites, we calculated the average {mu}, which was found to agree with experimental results of cold worked alloys for disordered Fe-Al alloy. On the other hand, antiferromagnetic coupling appears in the CsCl ordered structures. The average B{sub hf} was also calculated and compared to experimental data and the trends in the IS are considered. (orig.)

  5. WAHDAT AL WUJUD DALAM PEMIKIRAN IBNU ARABI

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    Abd Halim Rofi'ie

    2013-09-01

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

  6. Challenging the Réal Plan: An Examination of Human Rights and Socioeconomic Marginalization in Brazil

    Directory of Open Access Journals (Sweden)

    Alyssa Batchelor

    2015-08-01

    Full Text Available The purpose of this paper is to explore the relationship between the Réal Plan and its impact on Brazilian society – specifically marginalized groups such as impoverished, nonwhite, and indigenous communities. The first part of this research looks at the intersection of race, poverty, and income inequality. The latter looks at indigenous communities and their fight to retain their ancestral lands. By exploring why these groups have not attained any sort of social autonomy in spite of the Réal Plan in the past, we can identify the factors that have kept these groups oppressed and how to help these groups’ progress in the future.

  7. Strategic redirection of Al-Qaeda: from the leadership of Osama bin Laden to mass- dimension?

    Directory of Open Access Journals (Sweden)

    Rafat Ahmed Ghotme

    2012-06-01

    Full Text Available This article seeks to establish the relationship of global strategic variables of Al-Qaeda with religious ideology, political Islam, trying to incorporate a cross section and total phenomenon. It argues that the link lies in the expansion strategy and top-down decentralization created by the central base of Al-Qaeda, where regional networks have some autonomy but are determined by the central leadership and his adaptation of the Islamist ideology to an internationalist shed, revolutionary and violent organization.

  8. Arsenate uptake by Al nanoclusters and other Al-based sorbents during water treatment.

    Science.gov (United States)

    Mertens, Jasmin; Rose, Jérôme; Wehrli, Bernhard; Furrer, Gerhard

    2016-01-01

    In many parts of the world, arsenic from geogenic and anthropogenic sources deteriorates the quality of drinking water resources. Effective methods of arsenic removal include adsorption and coagulation with iron- and aluminum-based materials, of which polyaluminum chloride is widely employed as coagulant in water treatment due to its low cost and high efficiency. We compared the arsenic uptake capacity and the arsenic bonding sites of different Al-based sorbents, including Al nanoclusters, polyaluminum chloride, polyaluminum granulate, and gibbsite. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that As(V) forms bidentate-binuclear complexes in interaction with all Al-based removal agents. The octahedral configuration of nanoclusters and the distribution of sorption sites remain the same in all types of removal agents consisting of nano-scale Al oxyhydroxide particles. The obtained distances for As(V)-O and As(V)-Al agreed with previously published data and were found to be 1.69 ± 0.02 Å and 3.17-3.21 Å, respectively. Our study suggests that As(V) binds to Al nanoclusters as strongly as to Al oxide surfaces. The As sorption capacity of Al nanoclusters was found to be very similar to that of Al clusters in a polyaluminum chloride. The most efficient Al-based sorbents for arsenic removal were Al nanoclusters, followed by polyaluminum granulate. PMID:26613179

  9. 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.' ' '

  10. Electrical investigations of AlGaN/AlN structures for LEDs on Si(111)

    Energy Technology Data Exchange (ETDEWEB)

    Witte, H.; Rohrbeck, A.; Guenther, K.M.; Saengkaew, P.; Blaesing, J.; Dadgar, A.; Krost, A. [Department of Semiconductor Epitaxy, Institute of Experimental Physics, University of Magdeburg, 39106 Magdeburg (Germany)

    2011-07-15

    The carrier transport in AlGaN light emission diode (LED) structures on Si-substrates including an AlN multilayer (ML) buffer for reduction of defects was investigated using I-V-characteristics and admittance spectroscopy. Additionally, AlN on Si ML and AlN/AlGaN:Si on Si structures were grown and analyzed separately. The AlN-ML/AlGaN:Si heterojunction, and the pn-junction including the AlGaN/GaN multi quantum well (MQW)-structure were identified. As the main space charge regions (SCRs) controlling the carrier transport through the ultraviolet-light emission diode (UV-LED) structure the Si-substrate/AlN-ML heterojunctions pointed out. The I-V-characteristic of the LED structure is described by the series resistance of the AlN-ML and a parallel resistance with respect to the pn-junction. Interface defect states and/or deep defects impact the series resistance. The carrier transport through the LED structure is controlled by a tunnel process described by a Fowler-Nordheim (FN)-emission mainly through the AlN-ML buffer forming the series resistance. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Kritik al-Ghazali terhadap Kekekalan Alam

    OpenAIRE

    Sahidi Mustafa

    2015-01-01

    The concept of the creation of universe offered by Neo-Platonism philosopher such as al-Kindi, al-Farabi, and Ibnu Sina are philosophical concept existed and came as an early moment of development of Islamic philosophy interrelated to God, ultimately about his Existence and Characteristics. One of the topics is how God created the universe. According to al-Farabi and Ibnu Sina, God created this universe by way of emanation in order to prevent Himself from the new attitudes. Consequently, univ...

  12. Amyotrofinen lateraaliskleroosi (ALS) ja potilaan ohjaus

    OpenAIRE

    Korkeaniemi, Lotta; Kaakinen, Leena

    2009-01-01

    Saimme opinnäytetyömme toimeksiantona Hyvinkään sairaalan sisätautien vuodeosastolta. Tavoitteena oli luoda ALS potilaille potilasopas trakeostomiasta ja sen kanssa elämisestä. Oppaan tarkoituksena on auttaa ALS potilaita päättämään, kuinka pitkälle he haluavat viedä heidän hengitystukihoitonsa. Samalla hoitajat saavat tuki materiaalia, jonka avulla he voivat käydä läpi hengitystukihoitoja ja erityisesti trakeostomiaan liittyviä asioita. ALS eli amyotrofinen lateraaliskleroosi on tahdona...

  13. The wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

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

    2013-01-01

    This review article is focused on the research progress made utilizing the wobbler mouse as animal model for human motor neuron diseases, especially the amyotrophic lateral sclerosis (ALS). The wobbler mouse develops progressive degeneration of upper and lower motor neurons and shows striking...... similarities to ALS. The cellular effects of the wobbler mutation, cellular transport defects, neurofilament aggregation, neuronal hyperexcitability and neuroinflammation closely resemble human ALS. Now, 57 years after the first report on the wobbler mouse we summarize the progress made in understanding...

  14. Thermal diffusion in Ni/Al multilayer

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-02-05

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

  15. Linija za transport Al-polizdelkov

    OpenAIRE

    Capl, Žiga

    2012-01-01

    V diplomski nalogi je predstavljena linija za transport Al-polizdelkov, ki je sestavljena iz dveh verižnih transporterjev in dveh manipulatorjev. Omenjeni transporterji morajo transportirati Al-polizdelke od sprejemnega mesta do poti v stiskalnico. V okviru diplomskega dela smo opravili analizo obstoječega ogrodja z naklonom, linije za transport Al-polizdelkov in podali možne rešitve za novo učinkovitejšo izvedbo. Na podlagi tehnično-tehnoloških zahtev smo izbrali najprimernejšo rešitev i...

  16. The Ni-Al-Hf Multiphase Diffusion

    Directory of Open Access Journals (Sweden)

    Romanowska J.

    2016-06-01

    Full Text Available The generalized Darken method was applied to simulate the diffusion between γ-Ni| γ’-Ni3Al and γ’-Ni3Al|β-NiAl interfaces. The results of calculations were compared with the experimental concentration’s profiles of nickel, aluminum and hafnium in aluminide and hafnium doped aluminide coatings deposited by the CVD and PVD methods on pure nickel. The method deals with the Wagner’s integral diffusion coefficients and thermodynamic data - activities of components. The experimental results agree with the simulated ones.

  17. Die Poetik als Teil des aristotelischen Organon

    OpenAIRE

    Wels, Volkhard

    2016-01-01

    Der Aufsatz umreißt die Wirkung von Averroes’ Bearbeitung der aristotelischen ‚Poetik‘ als argumentativer Disziplin. Beginnend mit Al-Farabi und Al-Gazali im zehnten Jahrhundert wird die ‚Poetik‘ den logischen Disziplinen des ‚Organon‘ zugerechnet. Während die Theorie eines ‚poetischen Syllogismus‘ nicht rezipiert worden ist, wurde der argumentative Status der Dichtung vom zwölften Jahrhundert an auch im lateinischen Westen bekannt. Mit unterschiedlichen Begründungen übernahmen Dominicus Gund...

  18. TAFSIR SEMANTIK TERHADAP SURAT AL-KAFIRUN

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    Imam Muslimin

    2011-10-01

    Full Text Available The problems about the reading of al-Qur’an is always interesting to be discussed, in which the use of Arabic includes sound or ‘nash’ is acrucial factor to understand the implicit meaning of the Arabic-written texts. Al-Qur’an discusses problem based on the society’s culture. Al-Kafirun discusses not only about the normative theology but more about sociological contexts in which it tends to show transparency, fight against fanaticism and regionalism. And all of the will bring to the first process of the making of the text meaning to the situational context that creates them.

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

    Science.gov (United States)

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

    2016-08-01

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

  20. Oxidation of Al2O3 continuous fiber-reinforced/NiAl composites

    Science.gov (United States)

    Doychak, J.; Nesbitt, J. A.; Noebe, R. D.; Bowman, R. R.

    1992-01-01

    The 1200 C and 1300 C isothermal and cyclic oxidation behavior of Al2O3 continuous fiber-reinforced/NiAl composites were studied. Oxidation resulted in formation of Al2O3 external scales in a similar manner as scales formed on monolithic NiAl. The isothermal oxidation of an Al2O3/NiAl composite resulted in oxidation of the matrix along the fiber/matrix interface near the fiber ends. This oxide acted as a wedge between the fiber and the matrix, and, under cyclic oxidation conditions, led to further oxidation along the fiber lengths and eventual cracking of the composite. The oxidation behavior of composites in which the Al2O3 fibers were sputter coated with nickel prior to processing was much more severe. This was attributed to open channels around the fibers which formed during processing, most likely as a result of the diffusion of the nickel coating into the matrix.

  1. AlON粉体的合成%Synthesis of AlON Powder

    Institute of Scientific and Technical Information of China (English)

    赵小军; 茹红强; 张宁; 孙有政

    2009-01-01

    以α-Al_2O_3和AlN为原料,利用高温固相反应在氮气气氛下常压合成了AlON粉体.研究了成分配比、合成温度、保温时间对合成AlON粉体含量的影响,并通过热分析测试了合成过程热流和质量的变化.结果表明,当原料Al_2O_3和AlN的质量比为81:18、合成工艺为1750 ℃, 2 h时,得到AlON相的含量达到95%以上.

  2. A Rechargeable Al/S Battery with an Ionic-Liquid Electrolyte.

    Science.gov (United States)

    Gao, Tao; Li, Xiaogang; Wang, Xiwen; Hu, Junkai; Han, Fudong; Fan, Xiulin; Suo, Liumin; Pearse, Alex J; Lee, Sang Bok; Rubloff, Gary W; Gaskell, Karen J; Noked, Malachi; Wang, Chunsheng

    2016-08-16

    Aluminum metal is a promising anode material for next generation rechargeable batteries owing to its abundance, potentially dendrite-free deposition, and high capacity. The rechargeable aluminum/sulfur (Al/S) battery is of great interest owing to its high energy density (1340 Wh kg(-1) ) and low cost. However, Al/S chemistry suffers poor reversibility owing to the difficulty of oxidizing AlSx . Herein, we demonstrate the first reversible Al/S battery in ionic-liquid electrolyte with an activated carbon cloth/sulfur composite cathode. Electrochemical, spectroscopic, and microscopic results suggest that sulfur undergoes a solid-state conversion reaction in the electrolyte. Kinetics analysis identifies that the slow solid-state sulfur conversion reaction causes large voltage hysteresis and limits the energy efficiency of the system. PMID:27417442

  3. Mentoring: the ultimate professional relationship.

    Science.gov (United States)

    Belcher, A E; Sibbald, R G

    1998-04-01

    Mentoring plays a significant role in business, industry, government, education, and healthcare. Mentoring relationships help promote the individual's professional growth and development. Such development involves knowledge and skill acquisition, which is facilitated by interaction with other, more experienced and proficient professionals. The Belcher-Sibbald Continuum of Learning describes the relationship among the concepts of role modeling, networking, preceptoring, and mentoring. Each concept is defined and described as a unique relationship which promotes professional growth and development. In addition, three mentoring/networking relationships in the context of the wound care community are presented to provide insight into this type of relationship.

  4. Characterization of AlInN/AlN/GaN Heterostructures with Different AlN Buffer Thickness

    Science.gov (United States)

    Çörekçi, S.; Dugan, S.; Öztürk, M. K.; Çetin, S. Ş.; Çakmak, M.; Özçelik, S.; Özbay, E.

    2016-07-01

    Two AlInN/AlN/GaN heterostructures with 280-nm- and 400-nm-thick AlN buffer grown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD) have been investigated by x-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL) and Hall-effect measurements. The symmetric (0002) plane with respect to the asymmetric (10bar{1}2) plane in the 280-nm-thick AlN buffer has a higher crystal quality, as opposed to the 400-nm-thick buffer. The thinner buffer improves the crystallinity of both (0002) and (10bar{1}2) planes in the GaN layers, it also provides a sizeable reduction in dislocation density of GaN. Furthermore, the lower buffer thickness leads to a good quality surface with an rms roughness of 0.30 nm and a dark spot density of 4.0 × 108 cm-2. The optical and transport properties of the AlInN/AlN/GaN structure with the relatively thin buffer are compatible with the enhancement in its structural quality, as verified by XRD and AFM results.

  5. A study of the nanostructure and hardness of electron beam evaporated TiAlBN Coatings

    International Nuclear Information System (INIS)

    TiAlBN coatings have been deposited by electron beam (EB) evaporation from a single TiAlBN material source onto AISI 316 stainless steel substrates at a temperature of 450 oC and substrate bias of - 100 V. The stoichiometry and nanostructure have been studied by X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy. The hardness and elastic modulus were determined by nanoindentation. Five coatings have been deposited, three from hot-pressed TiAlBN material and two from hot isostatically pressed (HIPped) material. The coatings deposited from the hot-pressed material exhibited a nanocomposite nc-(Ti,Al)N/a-BN/a-(Ti,Al)B2 structure, the relative phase fraction being consistent with that predicted by the equilibrium Ti-B-N phase diagram. Nanoindentation hardness values were in the range of 22 to 32 GPa. Using the HIPped material, coating (Ti,Al)B0.29N0.46 was found to have a phase composition of 72-79 mol.% nc-(Ti,Al)(N,B)1-x+ 21-28 mol.% amorphous titanium boride and a hardness of 32 GPa. The second coating, (Ti,Al)B0.66N0.25, was X-ray amorphous with a nitride+boride multiphase composition and a hardness of 26 GPa. The nanostructure and structure-property relationships of all coatings are discussed in detail. Comparisons are made between the single-EB coatings deposited in this work and previously deposited twin-EB coatings. Twin-EB deposition gives rise to lower adatom mobilities, leading to (111) (Ti,Al)N preferential orientation, smaller grain sizes, less dense coatings and lower hardnesses.

  6. Evolution of ConAl clusters and chemisorption of hydrogen on ConAl clusters

    International Nuclear Information System (INIS)

    The growth behavior of ConAl (n = 1–15) and the chemisorptions of hydrogen on the ground state geometries have been studied using the density functional theory (DFT) within the generalized gradient approximation (GGA). The growth pattern for ConAl is Al-substituted Con+1 clusters, and it keeps the similar frameworks of the most stable Con+1 clusters except for n = 2, 3, and 6. The Al atom substitutes the surface atom of the Con+1 clusters for n ≤ 13. Starting from n = 14, the Al atom completely falls into the center of the Co-frame. The dissociation energy, the second-order energy differences, and the HOMO–LUMO gaps indicate that the magic numbers of the calculated ConAl clusters are 7, 9, and 13, corresponding to the high symmetrical structures. To my knowledge, this is the first time that a systematic study of chemisorption of hydrogen on cobalt aluminum clusters. The twofold bridge site is identified to be the most favorable chemisorptions site for one hydrogen adsorption on ConAl (n = 1–6, 8, 10), and two hydrogen adsorption on ConAl (n = 1–7), while threefold hollow site is preferred for one hydrogen adsorption on ConAl (n = 7, 9, 11–15) and two hydrogen adsorption on ConAl (n = 8–10, 12–15) clusters. The ground state structure of two hydrogen adsorption on Co11Al is exceptional. In general, the binding energy of both H and 2H of ConAl (n = 1–12) is found to increase with the cluster size. And the result shows that large binding energies of the hydrogen atoms and large fragmentation energies for Co11AlH and Co12AlH make these species behaving like magic clusters.

  7. Wali Allah menurut al-Hakim al-Tirmidzi dan Ibnu Taimiyyah

    Directory of Open Access Journals (Sweden)

    Lilik Mursito

    2015-12-01

    Full Text Available The discussion about wali presented in the early time on the hand of al-Hakim al Tirmidzi, which reaps number of responses from Muslim scholar because of his misleading. One of them is Ibn Taimiyyah. Al-Hakim and Ibn Taymiyyah have their own view about wali with several distinctions. In the definition of wali, al-Hakim al-Tirmidzi used more general language than Ibn Taimiyyah, as well as characteristics, how to be wali, the classification, concept of karamah, and the concept of khatm al-awliya’. According to writer, al-Hakim al-Tirmidzi’s view about wali able to deepen our understanding about Sufism, meanwhile Ibn Taimiyyah’s view will led us to comprehend Sufism from modernist point of view. This paper conclude that: both of figures seen that wali of Allah are the servants submissive and obedient in running His command; according to al-Hakim al Tirmidzi, degree of wali can be reached purely from Allah’s bounty and the effort of servants themselves, while Ibn Taimiyyah seen that the degree could be reached in the way of faith and piety of the servant; al-Hakim al-Tirmidzi seen that karamah is the most urgent for wali, while Ibn Taimiyyah did not; al-Hakim al-Tirmidzi utilized the quality of deeds to measure the best people and purity of heart to measure the best wali, while Ibn Taymiyyah utilized the quality of deeds as the assessment standard to measure best people and wali.

  8. Meaning in couples relationships.

    Directory of Open Access Journals (Sweden)

    Rodrigues T.F.

    2014-09-01

    Full Text Available Based on psycholinguistics and L. Vygotsky’s (2007 theories on sign, meaning and sense categories, as later discussed by A. Leontiev (2004, 2009, we present a case study that focuses on the intricacies of a love relationship for a woman who remained in a painful marriage. Interview material is presented in a Relational-Historical Psychology theoretical framework to provide central categories of meaning and sense. This is understood as a privileged method for apprehending the uniqueness of a human being. To segment the qualitative material, we used the “Analysis of the Nuclei of Meanings for the Apprehension of the Constitution of Sense,” by Aguiar and Ozella (2006, 2013. This approach seeks to discriminate the meanings and senses that constitute the content of a speech sample.

  9. Hot-top electromagnetic casting research of Al thin slab

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The hot-top EMC (electromagnetic casting) method was put forward, namely, the shape of top liquid column was formed by the hot-top in the screen and the semi-suspended liquid column was formed by the electromagnetic force nearby the liquid-solid interface frontier. Using the numerical simulating technique, the temperature distribution was discussed, the effect of parameters such as upper-conduct distance (UCD), cool ing water rate of flow, pouring temperature and liquid column height on casting velocity were studied, the relationship among them was confirmed finally. According to the calculated results, the hot-top EMC shaping system was designed and a lot of experiments were performed. The pure Al thin slabs of 480 mm × 20 mm × 850 mm were made successfully. The result showed that the casting velocity curve obtained experimentally almost coincides to the calculated one.

  10. Mechanical properties and oxidation behaviour of (Al,Cr)N and (Al,Cr,Si)N coatings for cutting tools deposited by HPPMS

    International Nuclear Information System (INIS)

    Hard coatings with high hardness, high oxidation resistance and thermal stability are used for economical machining. In this regard nanostructured (Cr,Al)N and nc-(Cr,Al)N/a-Si3N4 films were sputtered on tungsten carbide tools and WC/Co samples by using the HPPMS (High Power Pulse Magnetron Sputtering) technology. The relationship between coating composition, microstructure and mechanical properties was investigated by using X-ray diffraction, Scanning Electron Microscopy (SEM), and Nanoindentation. The maximum hardness value was about 40 GPa. For the coatings the Al-content was varied from 10-90 at.% while the silicon content was about 5 at.% for the (Cr,Al,Si)N. As this study focuses on oxidation behaviour of the deposited coatings, annealing tests were carried out in air at 1000 deg. C . HPPMS is a promising technology to ensure a uniform coating distribution, especially for complex shaped substrates like cutting tools or moulds. SEM pictures of the cross section have been taken around the cutting edge to determine the deposition rate and the film growth. The coatings morphology has been compared to m. f. (middle frequency)- and d. c. (direct current)-sputtered nanocomposite (Cr,Al,Si)N films indicating enhanced properties due to the application of the HPPMS-technology with regard to denser structure, higher hardness, favourable surface topography and better thickness uniformity

  11. Phase constitution and interface structure of nano-sized Ag-Cu/AlN multilayers: Experiment and ab initio modeling

    International Nuclear Information System (INIS)

    Nano-sized Ag-Cu8nm/AlN10nm multilayers were deposited by reactive DC sputtering on α-Al2O3(0001) substrates. Investigation of the phase constitution and interface structure of the multilayers evidences a phase separation of the alloy sublayers into nanosized grains of Ag and Cu. The interfaces between the Ag grains and the quasi-single-crystalline AlN sublayers are semi-coherent, whereas the corresponding Cu/AlN interfaces are incoherent. The orientation relationship between Ag and AlN is constant throughout the entire multilayer stack. These observations are consistent with atomistic models of the interfaces as obtained by ab initio calculations.

  12. 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

  13. Pesticides Linked to Raised Risk of ALS

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_158737.html Pesticides Linked to Raised Risk of ALS One toxin ... MONDAY, May 9, 2016 (HealthDay News) -- Exposure to pesticides and other chemicals may increase the risk for ...

  14. Data used in Xu et al., 2016

    Data.gov (United States)

    U.S. Environmental Protection Agency — Mercury emissions data from anthropogenic sources as described in Xu et al., 2016. This dataset is associated with the following publication: Xu, X., N. Liu, M....

  15. Smoking Tied to Shorter Survival with ALS

    Science.gov (United States)

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

  16. Het Nederlandse bos als vorm van bodemgebruik

    NARCIS (Netherlands)

    Slangen, L.H.G.; Boven, van B.

    1983-01-01

    Behandeling van de oppervlakte en verdeling van het bos en de veranderingen die hierin zijn opgetreden, met de bedrijfsgrootte-struktuur als belangrijke invalshoek daarbij; de rol van de overheid: doeleinden, instrumenten en effekten van het beleid

  17. Thermal Conductivity of Al-Salt Composites

    Science.gov (United States)

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

    2015-11-01

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

  18. Pesticides Linked to Raised Risk of ALS

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_158737.html Pesticides Linked to Raised Risk of ALS One toxin ... MONDAY, May 9, 2016 (HealthDay News) -- Exposure to pesticides and other chemicals may increase the risk for ...

  19. Calcium platinum aluminium, CaPtAl

    Directory of Open Access Journals (Sweden)

    Charles Fon Abi

    2011-10-01

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

  20. Stem Cells Deemed Safe for ALS Patients

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_159627.html Stem Cells Deemed Safe for ALS Patients But further research needed to see if injections into spine would provide any benefit, researchers say To use the sharing features on ...