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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. Baterías de Litio. La alternativa al plomo y al cadmio

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    Casañ Pastor, Nieves; Gómez-Romero, P.

    1996-01-01

    Además de la necesidad de mejoras técnicas en las baterías actuales, los usuarios deben saber que los elementos que las componen son altamente contaminantes, especialmente el plomo y el cadmio, y que en el caso de este último, los procesos de reciclado no están bien establecidos. Sin embargo, la demanda del mercado de baterías recargables es previsible que siga creciendo tanto a corto como a medio plazo. Así, la búsqueda de baterías más ligeras y de mayor densidad de energía para ...

  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. 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.

  5. Factores socioculturales que inciden en la adquisición de la lectoescritura de los niños y niñas que asisten al servicio de apoyo de la escuela de Bajo Plomo.

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    Cruz Prado, Karol

    2013-01-01

    Factores socioculturales que inciden en la adquisición de la lectoescritura de los niños que asisten al servicio de apoyo de la escuela de Bajo Plomo. De acuerdo con la investigación acerca de los factores socioculturales que inciden en la adquisición de la lectoescritura de los niños y niñas que asisten al servicio de apoyo de la escuela de Bajo Plomo estos se consideran como aquellas conductas, sentimientos, actitudes y acciones que emergen del contexto de interacción sociocultural de lo...

  6. Actividad de enzimas del estrés oxidativo en plantas de tomate cv. Amalia en respuesta al plomo

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    Machín Suárez, Alianna; Sánchez-Chávez, Esteban; Héctor Ardisana, Eduardo F; Santos-Cervantes, María E; Pérez Álvarez, Sandra

    2017-01-01

    RESUMEN La contaminación de los suelos por metales pesados es un resultado de la actividad humana, agricultura e industria. Entre los metales pesados el plomo es un contaminante potencial que en las plantas ocasiona numerosos síntomas de toxicidad como por ejemplo, crecimiento atrofiado, ennegrecimiento del sistema radical y clorosis generalizada. La actividad de las enzimas superóxido dismutasa (SOD; EC 1.15.1.1) y glutatión reductasa (GR; EC 1.8.1.7) se determinaron en hojas y tallos de pla...

  7. Screening for lead exposure in children in Belize Tamizaje de la exposición al plomo en niños de Belice

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    Andreas Charalambous

    2009-01-01

    representa 0,4% de los niños de ese grupo de edad en el país. Los niveles de plomo se analizaron mediante voltametría de redisolución anódica con un analizador ESA LeadCare. RESULTADOS: El nivel promedio de plomo en la sangre de los niños estudiados fue de 4,94 µg/dL (desviación estándar: 2,46. No obstante, 11 niños (7% tenían entre 10,1 y 13,8 µg/dL de plomo en la sangre, nivel de preocupación según los Centros de Control y Prevención de Enfermedades (CDC de los Estados Unidos de América. Los niños que vivían en los centros urbanos grandes Belice y Orange Walk presentaron mayores niveles de plomo (valores medios: 5,80 µg/dL y 5,74 µg/dL, respectivamente que los niños de las poblaciones más pequeñas Benque Viejo y San Pedro (4,17 µg/dL y 4,63 µg/dL, respectivamente. No se encontraron diferencias significativas entre los niños y las niñas. CONCLUSIONES: Estos resultados indican que los niños de Belice están expuestos al plomo y que a este estudio piloto debe seguir una investigación integral basada en una muestra mayor que correlacione los hallazgos con las características socioeconómicas, el comportamiento de los niños y el medio ambiente del hogar y la escuela.

  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 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

  9. Niveles de plomo en sangre y factores de riesgo por envenenamiento de plomo en niños mexicanos

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    Eduardo González Valdez

    2008-01-01

    Full Text Available El plomo (Pb es un contaminante ambiental que causa efectos adversos a la salud humana. La exposición humana al plomo se determina monitoreando su concentración en sangre, tomando en cuenta la influencia de varios factores, tales como edad, sexo, dieta y contaminación del aire. En este trabajo se analizó por duplicado la concentración de plomo en sangre de 80 niños que corresponde al 32% del total de menores de 15 años en la población del área minera de Vetagrande Zacatecas, México. Se usó voltamperometría de redisolución anódica siguiendo los criterios de la Norma Oficial Mexicana (NOM, la cual define seis categorías de contaminación. De los valores, 45% de los menores presentaron <10 µg/dL, 16,25%, 10-14 µg/dL, 33,75% 15-24 µg/dL y 5%, 25-44 µg/dL, que corresponden a las categorías de la II a la IV respectivamente. Los resultados en materia de salud revisten gran importancia ya que más del 50% de los niños tiene niveles de plomo en sangre que ameritan intervención por parte de los servicios de salud. La causa probable de la presencia de plomo en sangre se debe a que las casas habitación de esa población se encuentran asentadas en terrenos enriquecidos con plomo, y a través de una interacción el plomo se transporta hacia las personas.

  10. El cuadro clínico de la intoxicación ocupacional por plomo

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    Augusto V Ramírez

    2005-03-01

    Full Text Available Al plomo, metal pesado grisáceo y ubicuo, se le ha encontrado en lugares tan inverosímiles como los hielos fósiles de Groenlandia. Egipcios y hebreos lo usaron. Los fenicios c. 2000 AC trabajaron menas de plomo en España. Al final del s XX, en países desarrollados, la intoxicación por plomo pasó de problema ocupacional a problema de salud pública. Entre nosotros aún es frecuente la intoxicación ocupacional. El diagnóstico pasa por reconocer la existencia de plomo en el ambiente laboral y en tomar una buena historia clínica y ocupacional. El diagnóstico diferencial considera cuadros dolorosos neurológicos y abdominales. Plomo-sanguíneo y zinc-protoporfirina son análisis cruciales y fidedignos. En expuestos, el plomo-sanguíneo suele llegar a 40 ug/100 mL, aunque en trabajadores de industrias insalubres puede alcanzar 80 ug/100 mL y la zinc-protoporfirina ser mayor de 4 ug/g de hemoglobina. El tratamiento se basa en quelar el plomo casi específicamente con edetato disódico monocálcico, sin olvidar la penicilamida ni los nuevos ácido dimercapto-succínico y ácido dimercapto-propano-sulfónico, que han mejorado las opciones terapéuticas, son menos tóxicos y más fáciles de administrar. Se resalta la importancia del problema plomo como prioritario en salud pública y ocupacional, además de coadyuvar al grave problema ecológico actual.

  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. Efectos del plomo en la salud de la niñez

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    Matte Thomas D

    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.

  13. 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...

  14. La plancha de plomo en cubiertas y fachadas

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    Aramburu Maqua, Rocío

    1985-03-01

    Full Text Available A description is given of the properties of lead sheet for roofing and cladding purposes. Basic rules as far as installations are concerned are given, specially with respect to dimensions of the pieces, characteristics of Joints and fixings, and watertightness conditions. Compatibility of lead with other building materials is also taken into account, as well as elementary health and safety rules for its installation. Spanish standards on the subject are also reviewed.

    Se describen las características generales de la plancha de plomo con vistas a su utilización en cubiertas y fachadas. Se resumen las reglas básicas de instalación de la plancha en cubiertas y fachadas, en particular las que se refieren al tamaño de las piezas, características de las juntas y elementos de fijación, y condiciones de estanquidad. Se indican la compatibilidad del plomo con otros materiales de construcción para su instalación, así como las normas españolas de interés en este campo.

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

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    Meneses-González Fernando; Richardson Vesta; Lino-González Montserrat; Vidal María Teresa

    2003-01-01

    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 razó...

  17. Tóxidad de cadmio y plomo en pasto tanner Brachiaria arrecta

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    Manuel Peláez

    2014-12-01

    Full Text Available Se evaluó fisiopatías en Brachiaria arrecta expuestas a contenidos tóxicos de cadmio y plomo en el invernadero de la Universidad Nacional de Colombia Sede Palmira, se doparon plántulas sanas de 20 días de edad bajo cultivo hidropónico. El objetivo fue describir síntomas crecientes por intoxicación con el diseño de una escala valorativa de daños crecientes, adicionalmente se evaluaron cambios histológicos de raíz tallo y hojas mediante microscopia de luz de alta resolución (MLAR. Las plantas fueron sometidas a estrés abiótico con los tratamientos de sales de CdCl2 en concentración de 10 ppm, y de Pb (NO32 500 ppm, respectivamente. Los resultados principales mostraron un mayor detrimento cuando las plantas fueron expuestas al metal plomo que al cadmio en las raíces, tallos y hojas. Se apreciaron deformaciones extremas en paredes celulares de las células del cortex y en la endodermis de la raíz; en las hojas los daños fueron notorios para ambos metales sobre todo en el parénquima clorofílico y en la deformación de paredes de la epidermis tanto en haz como envés; en los tallos aparecieron deformaciones de las células del parénquima de relleno cuando ocurre bioacumulación intensa de plomo. Estos resultados sugieren que la bioconcentración en los tejidos vegetales ocasiona trastornos histológicos, que pueden involucrar una red trófica y por consiguiente consecuencias en la Salud Pública.

  18. FITORREMEDIACIÓN DE SUELOS CONTAMINADOS CON PLOMO UTILIZANDO AMARANTHUS SPINOSUS – AMARANTHACEAE EN CUSCO DEL 2012

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    PAIVA PRADO, GRETA MARGOT

    2016-01-01

    TOXICIDAD DEL PLOMO CONTAMINACIÓN DE SUELOS ACUMULACION DE METALES PESADOS EN EL SUELO REACCIONES DEL SUELO ANTE LA CONTAMINACIÓN EL SUELO COMO REGULADOR DE LA DISPONIBILIDAD DE LOS METALES PESADOS METALES PESADOS CONTAMINACIÓN POR METALES PESADOS METALES PESADOS EN EL AMBIENTE BIODISPONIBILIDAD DE LOS METALES PESADOS TIPOS DE PLOMO USOS DEL PLOMO METALES PESADOS EN LA SALUD PLOMO EN SUELOS Y PLANTAS PLOMO EN EL MEDIO AMBIENTE

  19. Lead exposure among children from native communities of the Peruvian Amazon basin Exposición al plomo en niños de comunidades indígenas de la cuenca del Amazonas en el Perú

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    Cynthia Anticona

    2012-04-01

    Full Text Available OBJECTIVE: To assess potential risk factors associated with elevated blood lead levels (BLLs among children in two communities from the Corrientes River basin in the Peruvian Amazon. METHODS: Children aged 0-17 years were screened for BLLs, hemoglobin levels, and anthropometric measures. Dwelling, family, and child data were collected through a parental questionnaire. Statistical analysis included descriptive and bivariate analysis. Multiple linear and logistic regressions using generalized estimating equations were also conducted to determine associated risk factors. A map of each community was drawn to examine the spatial distribution of BLLs. RESULTS: Of 208 children (88 from 23 households of the Peruanito community and 120 from 28 households of Santa Isabel, 27.4% had BLLs > 10 µg/dL. The geometric mean (± standard deviation BLL was 8.7 ± 4.0 µg/dL (range 3.0-26.8 µg/dL. In the total population, linear regression analysis indicated that age was positively associated with BLLs (P 10 µg/dL than girls (P 10 µg/dL had 45.0% higher odds of presenting BLLs > 10 µg/dL than children whose mothers had BLLs 10 µg/dL were the main risk factors for elevated BLLs. The higher risk in boys 7-17 years suggests that exposure could be related to specific activities in this group, such as fishing and hunting. Continuous monitoring of BLLs in the Corrientes River population is recommended.OBJETIVO: Evaluar los potenciales factores de riesgo asociados con niveles elevados de plomo en sangre (Pbs en niños de dos comunidades de la cuenca del río Corrientes en la Amazonia peruana. MÉTODOS: Se estudiaron de manera sistemática los niveles de PbS, la concentración de hemoglobina y las medidas antropométricas en niños de 0 a 17 años. A través de un cuestionario efectuado a los padres se recopilaron datos sobre la vivienda, la familia y los niños. El análisis estadístico incluyó el análisis descriptivo y de dos variables. También se llevaron a

  20. Uso de los datos de plumbemia para evaluar y prevenir el envenenamiento infantil por plomo en Latinoamérica

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    Romieu Isabelle

    2003-01-01

    Full Text Available La exposición al plomo es una amenaza seria para la salud de los niños, que se encuentra ampliamente distribuida en la Región de América Latina. Los funcionarios de salud pública necesitan identificar fuentes de exposición al plomo, así como sus efectos en la salud, para poder diseñar, implantar y evaluar las actividades preventivas y de control. Para evaluar la magnitud del problema del plomo es necesario definir tres elementos clave: a las fuentes potenciales de exposición, b los indicadores que se utilizarán para evaluar los efectos en la salud y la exposición en el medio ambiente, y c las estrategias de muestreo de la población en riesgo. Se pueden utilizar varias estrategias con el fin de seleccionar la población blanco dependiendo de los objetivos del estudio, el tiempo límite y los recursos disponibles. Si el objetivo es evaluar la magnitud y las fuentes del problema pueden emplearse los siguientes métodos de muestreo: a el muestreo al azar basado en la población; b el muestreo al azar basado en las facilidades dentro de los hospitales, las guarderías o las escuelas; c el muestreo objetivo de los grupos de alto riesgo; d el muestreo de conveniencia (de voluntarios, y e el reporte de los casos (éste puede conducir a la identificación de las poblaciones en riesgo, además de las fuentes de exposición. Para todos los diseños de muestreo, la información debe incluir tanto el uso de un cuestionario para el informe general de los participantes y de las fuentes potenciales locales de exposición, como la recolección de las muestras biológicas. En la interpretación de los datos se debe considerar el tipo de muestreo utilizado, el porcentaje de falta de respuesta y los factores que pueden influir en las mediciones del plomo en sangre, como la edad y la variación de la temporada. Las mediciones del plomo en la sangre se deben integrar dentro de una estrategia general para la prevención de toxicidad.

  1. 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.

  2. 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

    OpenAIRE

    Ordóñez Blanca Raquel; Romero Lidia Ruiz; Mora Refugio

    2003-01-01

    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 ...

  3. 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.

  4. 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

  5. EXPOSICION DE MENORES DE 7 AÑOS A UN ACOPIO DE PLOMO Y SU EFECTO A LARGO PLAZO SOBRE EL COEFICIENTE INTELECTUAL: ESTUDIO EN NIÑOS DE LA CIUDAD DE ANTOFAGASTA

    OpenAIRE

    IGLESIAS ALAMOS, VERONICA

    2007-01-01

    En 1998 se evaluó la plumbemia en menores de 7 años que vivían cercanos a un sitio de acopio de mineral de plomo. El 47,5% presentaba valores sobre 10 μg/dl. El principal factor de riesgo de tener plomo sanguíneo elevado fue vivir cercano al acopio y dado que éste fue removido fuera de la ciudad, asumimos que los niños tuvieron una exposición limitada. El propósito de este nuevo estudio fue determinar el efecto de la exposición limitada a plomo ambiental sobre el coeficiente intelectual. ...

  6. 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

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

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    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.

  8. 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

    Directory of Open Access Journals (Sweden)

    Ordóñez Blanca Raquel

    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.

  9. 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

  10. 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

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    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.

  11. Awortwi et al.: Mixing and stratification relationship on phytoplankton ...

    African Journals Online (AJOL)

    Awortwi et al.: Mixing and stratification relationship on phytoplankton of Lake Bosomtwe (Ghana) 43 West African Journal of Applied Ecology, vol. 23(2), 2015: 43–62. The Relationship Between Mixing and Stratification Regime on the Phytoplankton of Lake Bo.

  12. 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.

  13. Uso de cerámica vidriada como fuente de exposición a plomo en niños indígenas de zonas marginadas de Oaxaca, México

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    Martha Ma. Téllez Rojo Solís

    2015-05-01

    Full Text Available Objetivo. Conocer si el uso de lozo de barro vidriada (LBV se asocia con concentraciones de plomo en sangre en niños de zonas rurales de Oaxaca, México. Material y métodos. Se evaluó el uso de LBV en el hogar como principal fuente de exposición al plomo en 387 niños escolares indígenas de Oaxaca durante mayo de 2001. Resultados. Se encontró una diferencia ajustada de plomo en sangre (PbS (evaluada por Environmental Testing and Consulting [LeadCare] de 3.9μg/ dl (p<0.01 mayor en niños que reportaron usar (82% LBV en el hogar contra los que reportaron no usarlo. Además, 60 y 27% de los niños tuvieron concentraciones de PbS mayores o iguales a 10 y 20µg/dl, respectivamente. Conclusión. La intoxicación por plomo por el uso de LBV podría seguir siendo una preocupación para la salud pública en México

  14. Exposición a plomo en trabajadores de fábricas informales de baterías

    OpenAIRE

    Augusto V Ramírez

    2008-01-01

    Introducción: El problema del trabajo industrial con plomo es universal, sobretodo cuando se trabaja sin criterios de higiene ocupacional. En el Perú la industria minero metalúrgica del plomo mantiene programas de gestión en salud ocupacional de buena calidad, pero no sucede lo mismo en la industria informal del plomo. Objetivos: Investigar el estado de salud de trabajadores de fábricas artesanales e informales de baterías, usando como indicador de exposición nivel de plomo en sangre. Diseño:...

  15. 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.

  16. Modelo sistémico para evaluar la recuperación de suelos contaminados por plomo en el distrito de Concepción

    OpenAIRE

    Yarasca Bejarano, José Luis

    2015-01-01

    La fitorremediación se considera una tecnología viable y rentable emergente que tiene como responsabilidad limpiar los elementos traza de metales pesados como es el caso del plomo. Este método no ha sido muy propagada por la existencia de diversas dudas al respecto. Estos pueden resumirse como la incertidumbre del sistema de comportamientos en diferentes escenarios, tales como: contaminante, la concentración de contaminante y el comportamientos de la fisiología de la planta. Enfoques ante...

  17. ¿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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

  19. 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.

  20. 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

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

    OpenAIRE

    N. Martínez Riera; R.A. Sant Yacumo; N. Riera de Martínez Villa

    2001-01-01

    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), co...

  3. Relationship between the growth rate and Al incorporation of AlGaN by metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Deng, Y.; Zhao, D.G.; Le, L.C.; Jiang, D.S.; Wu, L.L.; Zhu, J.J.; Wang, H.; Liu, Z.S.; Zhang, S.M.; Yang, Hui; Liang, J.W.

    2011-01-01

    Research highlights: The growth rate and its relationship with Al content of MOCVD-grown AlGaN alloy films are investigated. It is found that both parasitic reaction and competitive adsorption play important roles in determining the growth rate and Al incorporation in AlGaN. Low reactor pressure and a decrease of absolute amount of Ga atoms arriving on the substrate may lead to a higher Al content in AlGaN film. The research results are helpful to control the Al content of AlGaN during the materials growth. - Abstract: The growth rate and its relationship with growth conditions of AlGaN alloy films by metalorganic chemical vapor deposition (MOCVD) are investigated. It is found that both parasitic reaction and competitive adsorption play important roles in determining the growth rate and Al incorporation in AlGaN. Low reactor pressure can weaken parasitic reactions, thus increasing the Al composition. In addition, a decrease of absolute amount of Ga atoms arriving on the substrate may lead to a lower Ga competitive power, and then a higher Al content in AlGaN film.

  4. Phase relationships in the Al-Ti-Ho system at 773 K

    Energy Technology Data Exchange (ETDEWEB)

    Jinli, H.; Jianlie, L.; Huaiying, Z.; Yinghong, Z.; Jialin, Y. [Guangxi Univ. (China). Inst. of Mater. Sci.

    2000-07-14

    The phase relationships in the Al-Ti-Ho ternary system at 773 K have been determined mainly by XRD techniques, with the aid of differential thermal analysis, EPMA, metallography. The existence of 10 binary compounds and two ternary phases, namely TiAl{sub 3}, TiAl{sub 2}, TiAl, Ti{sub 3}Al, Al{sub 17}Ho{sub 2}, Al{sub 3}Ho, Al{sub 2}Ho, AlHo, Al{sub 2}Ho{sub 3}, AlHo{sub 3}, Al{sub 43}Ti{sub 4}Ho{sub 6} and Al{sub 20}Ti{sub 2}Ho, respectively, have been confirmed. The section consists of 15 single-phase regions, 29 two-phase regions and 15 three-phase regions. (orig.)

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

    Directory of Open Access Journals (Sweden)

    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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2017-12-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. Plomo en sangre de cordón umbilical de neonatos nacidos en un hospital del norte de Lima

    Directory of Open Access Journals (Sweden)

    Daniel Guillén-Mendoza

    2013-06-01

    Full Text Available Con el objetivo de describir la concentración de plomo en sangre de cordón umbilical (SCU de recién nacidos (RN hijos de mujeres primíparas residentes en la zona norte de Lima (Perú se realizó un estudio transversal en el Hospital Nacional Cayetano Heredia entre julio de 2011 a diciembre de 2012. Se incluyeron 100 RN hijos de madres primigestas, que tenían un tiempo mínimo de residencia de 5 años en la zona norte de Lima. Se midió plomo en SCU de los RN por el método de adsorción atómica. Se encontró que 30% de los RN tuvieron nivel de plomo en SCU considerados de riesgo incrementado (= 3,0 µg/dL; en el 16% de los casos se encontró niveles tóxicos de plomo en SCU (= 5 µg/dL. Se concluye que existe un gran porcentaje de neonatos contaminados con plomo entre los RN de madres primigestas residentes en la zona norte de Lima.

  13. 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...

  14. PLOMO Y ARSÉNICO EN LA SUBCUENCA DEL ALTO ATOYAC EN TLAXCALA, MÉXICO

    Directory of Open Access Journals (Sweden)

    Edelmira García-Nieto

    2011-01-01

    Full Text Available Se evaluaron indicadores ambientales en el sistema hidrológico Zahuapan-Atoyac (SH:ZA, en Tlaxcala, México. Una región impactada por descargas de aguas residuales de origen urbano, agrícola e industrial. Las muestras fueron colectadas en la primavera del año 2008, época de estiaje. Se seleccionaron 16 estaciones de muestreo; abarcando desde el nacimiento del río Zahuapan, incluyendo tres muestras del río Atoyac, hasta su salida del estado de Tlaxcala. En las muestras de agua se midieron arsénico, plomo, pH y temperatura, en sedimentos; arsénico, plomo, textura, contenido de materia orgánica, carbono orgánico total, pH y conductividad eléctrica de acuerdo con NMX-AA-051-SCFI-2001, Goyberg-Reín y Vázquez, 2003 y la NOM-021-SEMARNAT-2000. Los resultados mostraron que el intervalo de concentraciones de arsénico osciló de 0.06 a 0.87 mg·L-1 en agua y de 1.3 a 127 mg·kg-1 en sedimento. Mientras que el plomo alcanzó niveles hasta de 1.05 mg·L-1 en agua del sitio denominado El Ojito y 89.5 mg·kg-1 en sedimento de la estación Apizaco. Estos niveles superaron las normas nacionales e internacionales establecidas para agua de consumo humano y protección de la vida acuática. Los resultados sugieren un aporte antropogénico en algunas estaciones que se suma a la contaminación de origen natural.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Análisis hidrodinámico de la inyección de partículas durante la refinación de plomo Análisis hidrodinámico de la inyección de partículas durante la refinación de plomo

    Directory of Open Access Journals (Sweden)

    Antonio Romero Serrano

    2012-02-01

    Full Text Available Pyro-refining is one of the techniques used in recycling lead. Two significant stages in theprocess are decopperization and desilverization, which are traditionally done by addingpowdered Sulfer and Zinc at the surface of the lead bath and then mixing it with a propeller.The efficiency of this process has been improved by using a submerged lance to injectthe reactants into the interior of the lead bath, but the hydrodynamics of this new methodhas not yet been studied until now. The aim of this study was to refine the techniquesfor injecting particles into lead baths by performing mathematical simulations using theCOMSOL 3.4 software. Residence and mixing times were produced for different injectionvelocities, and the simulation results for residence times were validated by experimentaldata obtained in the laboratory.Una técnica en el reciclaje de plomo es la piro-refinación, en donde las etapas de interés son: el decobrizado y el deplatado; que consisten en adicionar azufre y zinc en polvo, respectivamente en la superficie del baño de plomo y posteriormente se agita con una hélice. Este procedimiento ineficiente, se optimizo al inyectar los reactivos a través de una lanza en el seno del baño, lo cual incremento la eficiencia del proceso. El aspecto hidrodinámico del proceso de inyección no ha sido aún estudiado, por lo que en este trabajo, se estudio el comportamiento hidrodinámico de la inyección de partículas a través de una lanza sumergida en baños de plomo mediante simulación matemática con la aplicación del software COMSOL 3.4. Se obtuvieron los tiempos de residencia y mezclado a diferentes velocidades de inyección. Los resultados del tiempo de residencia de la simulación se validaron con datos obtenidos experimentalmente en pruebas realizadas a nivel laboratorio obteniendo una buena similitud entre ambos.

  17. 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.

  18. Exposición a plomo en trabajadores de fábricas informales de baterías

    Directory of Open Access Journals (Sweden)

    Augusto V Ramírez

    2008-06-01

    Full Text Available Introducción: El problema del trabajo industrial con plomo es universal, sobretodo cuando se trabaja sin criterios de higiene ocupacional. En el Perú la industria minero metalúrgica del plomo mantiene programas de gestión en salud ocupacional de buena calidad, pero no sucede lo mismo en la industria informal del plomo. Objetivos: Investigar el estado de salud de trabajadores de fábricas artesanales e informales de baterías, usando como indicador de exposición nivel de plomo en sangre. Diseño: Estudio de tipo observacional y transversal. Lugar de estudio: Fábricas de baterías del sector informal en el sur del Perú y en el Servicio de Salud Ocupacional Hospital Ilo, Perú. Participantes: Trabajadores de cuatro fábricas de baterías del sector informal. Intervenciones: La información se obtuvo mediante entrevista directa a 41 trabajadores. El estudio fue realizado entre agosto 1999 y enero 2000. Para medir plomo sanguíneo, se utilizó espectrofotometría de absorción atómica con horno de grafito y para hemoglobina, microhematocrito. Se obtuvo datos en porcentajes, promedios, rangos y desviaciones estándar. Se comparó los resultados de niveles de plomo sanguíneo con variables de salud e higiene ocupacional. Principales medidas de los resultados: Asociación entre plomo sanguíneo y síntomas de saturnismo. Resultados: La edad promedio del grupo fue 35 años (rango: 16 a 52, media de tiempo de trabajo, 6,5 años. El promedio de plomo sanguíneo fue 37,7 ug/dL (rango: 13,5 a 72,3, desviación estándar: 15,7, hemoglobina media 11,2 g/dL (rango: 8,9 - 13,2, desviación estándar 1,1. Se halló asociación estadística significativa entre plomo sanguíneo elevado y síntomas de saturnismo (p<0,05, trabajo como soldador-fundidor (p<0,001 y malos hábitos de higiene ocupacional (p<0,05. Conclusiones: La salud del trabajador en este grupo ocupacional se encontró afectada. El valor medio de plomo sanguíneo encontrado fue 37,7 ug/dL y la

  19. The relationship between viscosity and refinement efficiency of pure aluminum by Al-Ti-B refiner

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-30

    The relationship between viscosity and refinement efficiency of pure aluminum with the addition of Al-Ti-B master alloy was studied in this paper. The experimental results show that when the grain size of solidified sample is finer the viscosity of the melt is higher after the addition of different Al-Ti-B master alloys. This indicates that viscosity can be used to approximately estimate the refinement efficiency of Al-Ti-B refiners in production to a certain extent. The main reason was also discussed in this paper by using transmission electron microscopy (TEM) analysis and differential scanning calorimetry (DSC) experiment.

  20. USO POTENCIAL DEL HUIZACHE (Acacia farnesiana L. Will EN LA FITORREMEDIACIÓN DE SUELOS CONTAMINADOS CON PLOMO

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    Oscar Landeros-Márquez

    2011-01-01

    Full Text Available Se ha realizado un gran número de estudios para identificar los efectos de los metales pesados en plantas cultivadas y en algunas especies consideradas como hiperacumuladoras. Sin embargo, pocos esfuerzos se han dedicado a la evaluación de especies vegetales nativas de zonas áridas para fitorremediación. Este estudio se llevó a cabo ex situ para evaluar la tasa de fitoextracción de plomo en Acacia farnesiana L. Will. Se utilizaron árboles jóvenes (n=48, colocados en macetas plásticas, en donde se agregó una combinación de tres concentraciones de plomo (0, 250 y 500 mg·kg-1 en forma de Pb(NO32 y cuatro dosis de nitrógeno (0, 100, 300 y 500 mg·kg-1 en forma de Fosfo-Nitrato (33-03-00. Se evaluó la tasa fotosintética y la concentración de plomo en raíz, tallo y hoja. Las dosis de nitrógeno y las concentraciones de plomo por separado no produjeron diferencias significativas en la tasa fotosintética de las plantas de huizache, pero la interacción entre esos dos factores fue estadísticamente significativa (P=0.0074, encontrándose que la mayor acumulación de plomo ocurrió en la parte aérea de la planta con una media de 352.34 mg·kg-1.

  1. 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

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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.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

  2. 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

  3. Potenciales evocados somatosensitivos en una poblacion cronicamente intoxicada con plomo

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    O. M. Genovese

    1990-03-01

    Full Text Available Once pacientes con cifras elevadas de plombemia y disminuidas de delta aminolevulínico dehidrasa (ALA D, fueron estudiados mediante la realización de potenciales evocados somatosensitivos obtenidos por estimulación del nervio mediano, midiendo el ingreso medular, el arribo cortical v el tiempo de conducción central (TCC. Los datos fueron comparados con controles. Se correlacionaron con las deterniinaciones bioquímicas y con el tiempo de exposición al tóxico. Por encima dei limite superior control, se encontro el ingreso medular en tres pacientes, el arribo cortical en cuatro y el TCC en tres. Los valores de N13,N20 y TCC no mostraron correlación con los parâmetros bioquímicos ni con el tiempo de exposición al tóxico. Estos hallazgos sugieren que, si bien la neuropatía periférica condiciona el retraso dei ingreso medular y del arribo cortical, es probable que exista también compromiso de la mielina central en algunos de los pacientes crónicamente expuestos.

  4. 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

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    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.

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

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    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.

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

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    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

  7. 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

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    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.

  8. Cuantificación de plomo, cadmio y cromo mediante sialoquímica

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    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.

  9. Adsorción de plomo y cadmio en sistema continuo de lecho fijo sobre residuos de cacao

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    Jose Lara

    2016-12-01

    Full Text Available Se evaluó el desempeño de la cáscara de cacao como material residual adsorbente de metales pesados (Plomo y Cadmio en solución acuosa sintética, mediante un sistema continuo de lecho fijo. El trabajo experimental consistió en determinar el efecto de la altura del lecho en la remoción de estos contaminantes, manteniendo constantes parámetros como el pH, velocidad de flujo y concentración inicial de los metales. Las pruebas de adsorción presentaron una remoción de 91,32 y 87,80% respectivamente para Pb y Cd después de transcurridos 4,5 h La medición de las concentraciones en solución acuosa de los iones metálicos se hizo por adsorción atómica. Se evaluó el ajuste de los modelos matemáticos de Thomas, Dosis-Respuesta, Adams-Bohart y BDST (Bed-Depht Service Time analysis, para predecir el comportamiento dinámico de la columna y obtener los parámetros cinéticos correspondientes. Para los modelos de Thomas y de Dosis-Respuesta, se observó que los valores de la capacidad inicial de adsorción, q0, disminuyeron al aumentar la altura del lecho, esto pudo deberse a una transferencia de masa más lenta, concentración más baja y aumento dela capacidad de adsorción, mientras que los modelos de Adams-Bohart y BDST, la capacidad de adsorción volumétrica, N0, decrece al aumentar el bioadsorbente en la columna. Los resultados presentados en este estudio indican que los residuos de cacao pueden ser usados para la remoción de metales pesados presentes en aguas residuales satisfactoriamente.

  10. Una etiqueta de plomo con fitónimos procedente de Mas Vell : (Vallmoll, ager Tarraconensis

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    Diana Gorostidi Pi

    2012-01-01

    Full Text Available Presentación de una nueva etiqueta de plomo hallada casualmente en una zona rural del ager Tarraconensis. La pieza presenta dos líneas de texto en las que se ha podido reconocer la presencia de dos fitónimos. La placa está provista de un apéndice lateral en el que se sitúa el agujero para el hilo o cuerda que la unía a la vasija o contenedor. Este elemento resulta muy poco usual en este tipo de documentos epigráficos.A new lead label has been found by chance in a rural area of the ager Tarraconensis. The piece has two writing lines with two plant names. The plate is provided with a lateral appendix with a hole for the filament that connected it to the vessel or box. This element is very unusual in this type of epigraphic documents.

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

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    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.

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

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    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.

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, S., E-mail: svaldez@fis.unam.mx [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Av. Universidad S/N, Col. Chamilpa, 062210 Cuernavaca, Morelos (Mexico); Perez, R.; Rodriguez-Diaz, R.A. [Instituto de Ciencias Fisicas-Universidad Nacional Autonoma de Mexico, Av. Universidad S/N, Col. Chamilpa, 062210 Cuernavaca, Morelos (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Eje central Lazaro Cardenas 152, Mexico D.F. 07730 (Mexico); Casolco, S.R. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Puebla, Via Atlixcayotl 2301. Puebla, Pue. 2800 (Mexico)

    2010-05-25

    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 {eta}-phase and {alpha}-Al solid solution with Zn dissolved into the matrix. The silver concentration in AlZn alloy influences the volume of AgZn{sub 3} 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.

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

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    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.

  16. 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

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    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Fei [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    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

  18. Adsorción de plomo y cadmio en sistema continuo de lecho fijo sobre residuos de cacao

    OpenAIRE

    Jose Lara; Candelaria Tejada; Angel Villabona; Alfonso Arrieta; Clemente Granados Conde

    2016-01-01

    Se evaluó el desempeño de la cáscara de cacao como material residual adsorbente de metales pesados (Plomo y Cadmio) en solución acuosa sintética, mediante un sistema continuo de lecho fijo. El trabajo experimental consistió en determinar el efecto de la altura del lecho en la remoción de estos contaminantes, manteniendo constantes parámetros como el pH, velocidad de flujo y concentración inicial de los metales. Las pruebas de adsorción presentaron una remoción de 91,32 y 87,80%...

  19. Tratamientos postfermentativos del vinagre: conservación en botella, envejecimiento acelerado y eliminación del plomo

    OpenAIRE

    Labbé Pino, Mariela Alejandra

    2007-01-01

    La presente investigación se ha dividido en tres temas, el primero de ellos ha estudiado los efectos de diferentes condiciones de almacenamiento sobre las características de vinagres comerciales. El segundo, ha estudiado el envejecimiento de vinagres con virutas de roble. Finalmente, se ha estudiado la reducción de plomo en vinagres a nivel trazas mediante el uso de una resina de intercambio catiónico. En el estudio de conservación, se han empleado vinagres de manzana y de vino chardonnay, ca...

  20. 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.

  1. Sistema basado en conocimiento para baterías de plomo ácido aplicado a microcontroladores PIC

    OpenAIRE

    Farfán, Roberto Federico; Cadena, Carlos Alberto

    2017-01-01

    En el siguiente trabajo se evalúa el comportamiento de un algoritmo de control, incorporado en un microcontrolador PIC que actúa como cerebro de un regulador fotovoltaico. Este algoritmo se diseño utilizando lógica difusa y en el trabajo se realizo un seguimiento del plano de control que usa el sistema en la carga de baterías de plomo ácido. Para desarrollar un sistema de control difuso, se necesita información del comportamiento del sistema a controlar y volcar esta información en la base de...

  2. The Relationship Between Gambling and Homelessness: A Commentary on Sharman et al. (2014).

    Science.gov (United States)

    Griffiths, Mark D

    2015-12-01

    The relationship between problem gambling and homelessness is a little studied area in the gambling studies field. A recent study by Sharman et al. (J Gambl Stud, doi: 10.1007/s10899-014-9444-7, 2014) is the first quantitative study in Great Britain on this interesting and important topic. In this context, the study is to be commended and provides an empirical benchmark on which other studies can build. The study reported a problem gambling prevalence rate of 11.6% and is significantly higher than the problem gambling rate of the general population in Great Britain (which is problem gambling among the homeless into the wider context of problems among the homeless more generally (particularly in relation to mental health problems and other addictive behaviors), (2) highlights some of the methodological problems and weaknesses of the study, and (3) notes a number of factual errors made in the paper.

  3. [Relationship between Fe, Al oxides and stable organic carbon, nitrogen in the yellow-brown soils].

    Science.gov (United States)

    Heng, Li-Sha; Wang, Dai-Zhang; Jiang, Xin; Rao, Wei; Zhang, Wen-Hao; Guo, Chun-Yan; Li, Teng

    2010-11-01

    The stable organic carbon and nitrogen of the different particles were gained by oxidation of 6% NaOCl in the yellow-brown soils. The relationships between the contents of selective extractable Fe/Al and the stable organic carbon/nitrogen were investigated. It shown that amounts of dithionite-citrate-(Fe(d)) and oxalate-(Fe(o)) and pyrophosphate extractable (Fe(p)) were 6-60.8 g x kg(-1) and 0.13-4.8 g x kg(-1) and 0.03-0.47 g x kg(-1) in 2-250 microm particles, respectively; 43.1-170 g x kg(-1) and 5.9-14.0 g x kg(-1) and 0.28-0.78 g x kg(-1) in nitrogen, higher in paddy yellow-brown soils than in arid yellow-brown soils, were 0.93-6.0 g x kg(-1) and 0.05-0.36 g x kg(-1) in 2-250 microm particles, respectively; 6.05-19.3 g x kg(-1) and 0.61-2.1 g x kg(-1) in nitrogen (C(stable)/N(stable)) were 9.50-22.0 in 2-250 microm particles and 7.43-11.54 in nitrogen were 14.3-50.0 and 11.9-55.6 in 2-250 microm particles, respectively; 53.72-88.80 and 40.64-70.0 in nitrogen are advantageously conserved in paddy yellow-brown soil. An extremely significant positive correlation of the stable organic carbon and nitrogen with selective extractable Fe/Al is observed. The most amounts between the stable organic carbon and nitrogen and selective extractable Fe/Al appear in clay particles, namely the clay particles could protect the soil organic carbon and nitrogen.

  4. Plomo metálico en yacimientos de la I Edad del Hierro en la Provincia de Castellón: Explotación de recursos mineros y circulación del metal

    OpenAIRE

    Montero Ruiz, Ignacio; Aguilella, Gustau; Rovira Hortalá, Carmen

    2014-01-01

    Las investigaciones que estamos realizando en yacimientos de la I Edad del Hierro en la provincia de Castellón nos han permitido estudiar algunos de los primeros objetos de plomo caracterizando su composición mediante ED-XRFy ICP-MS. También se ha realizado un trabajo de localización de minas de plomo en la provincia, analizando las muestras recogidas en ellas para determinar su potencial uso para obtener plomo metálico o para extracción de plata. Finalmente tanto del material arqueológ...

  5. 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.

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

    OpenAIRE

    Ruiz López, Carmen

    2016-01-01

    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.

  7. Exposición a plomo en niños de 6 a 12 años de edad

    Directory of Open Access Journals (Sweden)

    Jiménez-Gutiérrez Carlos

    1999-01-01

    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.

  8. REMOCIÓN DE PLOMO EN AGUA A PARTIR DE MATERIAL NANOESTRUCTURADO, NANOTUBOS DE CARBONO SOPORTADOS EN ZEOLITA NATURAL

    Directory of Open Access Journals (Sweden)

    Holanda I. Cruz

    2017-01-01

    Full Text Available En este trabajo se realizó la cinética de remoción de plomo en agua con un material nanoestructurado, nanotubos de carbono soportados en zeolita (NTC-ZN, y con zeolita natural (ZN. La zeolita utilizada proviene de los Valles Centrales de Oaxaca, México. El material nanoestructurado se sintetizó por el método de aspersión pirolítica bajo condiciones especificas; se caracterizó por microscopía electrónica de barrido y de transmisión (SEM y TEM y determinación de área superficial (BET. Los materiales se probaron con una solución de plomo a una concentración de 10 ppm bajo condiciones de agitación y filtrado a vacío. El filtrado se caracterizó por espectrometría de masas con plasma acoplado inductivamente (ICP-MS. Los porcentajes de remoción fueron de 99.96% para NTC-ZN y 99.27% para la zeolita natural en 120 minutos. Sin embargo un 94.5% de remoción se presenta en un tiempo 6 veces menor con el híbrido que con ZN.

  9. Uso de los datos de plumbemia para evaluar y prevenir el envenenamiento infantil por plomo en Latinoamérica Use of blood lead data in epidemiological studies to assess and prevent childhood lead poisoning in Latin America

    Directory of Open Access Journals (Sweden)

    Isabelle Romieu

    2003-01-01

    Full Text Available La exposición al plomo es una amenaza seria para la salud de los niños, que se encuentra ampliamente distribuida en la Región de América Latina. Los funcionarios de salud pública necesitan identificar fuentes de exposición al plomo, así como sus efectos en la salud, para poder diseñar, implantar y evaluar las actividades preventivas y de control. Para evaluar la magnitud del problema del plomo es necesario definir tres elementos clave: a las fuentes potenciales de exposición, b los indicadores que se utilizarán para evaluar los efectos en la salud y la exposición en el medio ambiente, y c las estrategias de muestreo de la población en riesgo. Se pueden utilizar varias estrategias con el fin de seleccionar la población blanco dependiendo de los objetivos del estudio, el tiempo límite y los recursos disponibles. Si el objetivo es evaluar la magnitud y las fuentes del problema pueden emplearse los siguientes métodos de muestreo: a el muestreo al azar basado en la población; b el muestreo al azar basado en las facilidades dentro de los hospitales, las guarderías o las escuelas; c el muestreo objetivo de los grupos de alto riesgo; d el muestreo de conveniencia (de voluntarios, y e el reporte de los casos (éste puede conducir a la identificación de las poblaciones en riesgo, además de las fuentes de exposición. Para todos los diseños de muestreo, la información debe incluir tanto el uso de un cuestionario para el informe general de los participantes y de las fuentes potenciales locales de exposición, como la recolección de las muestras biológicas. En la interpretación de los datos se debe considerar el tipo de muestreo utilizado, el porcentaje de falta de respuesta y los factores que pueden influir en las mediciones del plomo en sangre, como la edad y la variación de la temporada. Las mediciones del plomo en la sangre se deben integrar dentro de una estrategia general para la prevención de toxicidad.Exposure to lead is a

  10. MODELO CONCEPTUAL DE RIESGO AMBIENTAL POR ARSÉNICO Y PLOMO EN EL DISTRITO MINERO DE SANTA MARÍA DE LA PAZ, SAN LUIS POTOSÍ, MÉXICO

    Directory of Open Access Journals (Sweden)

    Carlos Chávez T.

    2011-01-01

    Full Text Available Con el fin de caracterizar el riesgo ambiental de un sitio contaminado en México, que se localizaen un distrito minero del estado de San Luis Potosí, se construyó su modelo conceptual. El sitio presenta niveles altos de plomo y arsénico en medios ambientales por la dispersión ambiental de residuos y emisiones de la actividad minera histórica y del presente. En la elaboración del modelo, se utilizaron procedimientos sistemáticos aprobados por la normatividad internacional e información histórica del sitio sobre contaminación, impacto y riesgo ambiental para el periodo 1995-2008. El modelo sirvió para 1 establecer conexiones Fuente-Ruta-Receptor, 2 detectar zonas donde ocurren rutas completas de exposición al arsénico y al plomo, y 3 confirmar zonas de mayor riesgo susceptibles de aplicar criterios de remediación de suelos contaminados conforme a la normatividad mexicana. Según indica el estudio, la zona de mayor potencial de riesgo corresponde a la nombrada como Villa de la Paz, destacando al arsénico como el problema principal. Modelos conceptuales en sitios mineros contaminados de EE.UU., Portugal, Irlanda y Australia han servido como herramientas para describir fuentes potenciales, rutas y posibles receptores, realizar el proceso de evaluación de riesgo, y para evaluar la factibilidad de remediación del sitio, entre otros. La normatividad mexicana recomienda elaborar el modelo conceptual en estudios de evaluación de riesgo ambiental y para la remediación del sitio. No obstante, no existen casos documentados en revistas científicas sobre la construcción de estos modelos en sitios mineros de México. Uno de los beneficios potenciales del uso del modelo propuesto, es que, una vez que ha sido simplificada la información, puede ser una herramienta básica para el desarrollo de evaluaciones ambientales del sitio estudiado y una guía para la construcción de modelos en otros sitios mineros de México.

  11. Internet Addiction and Its Relationship with Self-Efficacy Level among Al-Hussein Bin Talal University Students

    Science.gov (United States)

    Alrekebat, Amjad Farhan

    2016-01-01

    The aim of this study was to identify the Internet addiction and its relationship to self-efficacy level among Al-Hussein Bin Talal University students. The study sample consisted of 300 female and male students, who were selected randomly. The participants completed a questionnaire that consisted of two scales: Internet addiction which was…

  12. 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.

  13. Phase relationship in AL-Cu-Sc alloys at 450-500 deg C

    International Nuclear Information System (INIS)

    Kharakterova, M.L.

    1991-01-01

    Al-Cu-Sc alloys containing up to 40% Cu and up to 6% Sc at 450 deg C and 500 deg C are studied using light microscopy, X-ray-spectral microanalysis, X-ray diffraction analysis, scanning electron microscopy, measurement of microhardness and electric resistance. It is determined, that in equilibrium with aluminium solid solution under the given temperature ther are Al 3 Sc, CuAl 2 phases of the respective binary systems and W (ScCu 6.6-4 Al 5.4-8 ) ternary phase. Isothermal cross sections of Al-Cu-Sc system at 450 and 500 deg C are plotted. Microhardness of equilibrium phases is measured. Combined solubility of copper and scandium in aluminium is determined

  14. 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

  15. The relationship between Al and Si in biogenic silica as determined by PIXE and XAS

    International Nuclear Information System (INIS)

    Beck, L.; Gehlen, M.; Flank, A.-M.; Bennekom, A.J. van; Beusekom, J.E.E. van

    2002-01-01

    Biogenic silica, one of the major constituents of marine sediments, is a potentially powerful paleoceanographic tool, revealing information on past productivity. Interpreting the sedimentary records of the biogenic silica requires, however, an understanding of its preservation. Dissolution of biogenic silica is controlled by the presence of trace elements such as Al. The work in this paper focuses on the association of Al and Si in biogenic silica. The composition and the atomic structure of cultured and natural diatoms were determined by using PIXE and XAS techniques. This study provides the first evidence for a structural association of Al and Si in biogenic silica

  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. Evaluación del efecto tóxico del acetato plomo y el cloruro de cromo sobre el metabolismo bacterial anaerobio

    Directory of Open Access Journals (Sweden)

    Beatriz Wills

    2004-01-01

    Full Text Available Se presentan los resultados del estudio de toxicidad del cloruro de cromo (CrCl3 y el acetato de plomo (CH3COO2Pb del lodo de un reactor anaerobio de flujo ascendente y manto de lodos (UASB, aclimatado y estabilizado en el laboratorio con una solución de suero en polvo sintético; los ensayos de toxicidad se realizaron en botellas serológicas de 60 mL, se utilizaron como sustratos soluciones de ácido fórmico y suero en polvo sintético y se ensayaron concentraciones de cloruro de cromo en el rango de 1.000 a 5.000 mg/L, y de 1.000 a 10.000 mg/L para el acetato de plomo. Durante 72 horas se valoró la producción de metano en mL y el comportamiento del potencial redox en mV.Se presentaron reducciones del 50% en la producción de metano a concentraciones de 3.322 mg/L para cloruro de cromo y 1.415 mg/L para el acetato de plomo cuando el sustrato fue ácido fórmico, y a 2.291 mg/L para el cloruro de cromo y 1.982 mg/L para el acetato de plomo cuando el sustrato fue suero en polvo sintético.En síntesis, el artículo demuestra que las bacterias metanogénicas tienen un grado de resistencia cuantificable con respecto a las diferentes concentraciones de metales aplicados

  18. Evolución temporal de la contaminación por plomo y cadmio en la zona intermareal de la ría de Vigo

    Directory of Open Access Journals (Sweden)

    M. Pérez López

    2004-12-01

    Full Text Available 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.

  19. Microstructure and Tensile/Corrosion Properties Relationships of Directionally Solidified Al-Cu-Ni Alloys

    Science.gov (United States)

    Rodrigues, Adilson V.; Lima, Thiago S.; Vida, Talita A.; Brito, Crystopher; Garcia, Amauri; Cheung, Noé

    2018-03-01

    Al-Cu-Ni alloys are of scientific and technological interest due to high strength/high temperature applications, based on the reinforcement originated from the interaction between the Al-rich phase and intermetallic composites. The nature, morphology, size, volume fraction and dispersion of IMCs particles throughout the Al-rich matrix are important factors determining the resulting mechanical and chemical properties. The present work aims to evaluate the effect of the addition of 1wt%Ni into Al-5wt%Cu and Al-15wt%Cu alloys on the solidification rate, macrosegregation, microstructure features and the interrelations of such characteristics on tensile and corrosion properties. A directional solidification technique is used permitting a wide range of microstructural scales to be examined. Experimental growth laws relating the primary and secondary dendritic spacings to growth rate and solidification cooling rate are proposed, and Hall-Petch type equations are derived relating the ultimate tensile strength and elongation to the primary dendritic spacing. Considering a compromise between ultimate tensile strength and corrosion resistance of the examined alloys samples from both alloys castings it is shown that the samples having more refined microstructures are associated with the highest values of such properties.

  20. Structure-property relationships in directionally solidified single crystal NiAl

    Science.gov (United States)

    Noebe, R. D.; Kim, J. T.; Gibala, R.

    1987-01-01

    The ordered intermetallic alloy NiAl is being considered as a potential high temperature structural material, but lack of ductility at ambient temperatures, especially in polycrystalline form, is presently a major obstacle in achieving this goal. Even general agreement of the intrinsic ductility that can be achieved in monocrystals is in dispute. In order to understand this problem, two directionally solidified ingots of NiAl which displayed known differences in ductility were characterized in sufficient detail to identify the corresponding microstructural differences. It was found that the type and size of casting defects, i.e., porosity, present in the material were the major factors in controlling ductility of NiAl single crystals and could explain the order of magnitude variance in fracture strains reported in the literature.

  1. Microstructure/processing relationships in high-energy high-rate consolidated powder composites of Nb-stabilized Ti3Al+TiAl

    Energy Technology Data Exchange (ETDEWEB)

    Persad, C.; Lee, B.; Hou, C.; Eliezer, Z.; Marcus, H.L.

    1989-01-01

    A new approach to powder processing is employed in forming titanium aluminide composites. The processing consists of internal heating of a customized powder blend by a fast electrical discharge of a homopolar generator. The high-energy high-rate '1MJ in 1s' pulse permits rapid heating of an electrically conducting powder mixture in a cold wall die. This short time at temperature approach offers the opportunity to control phase transformations and the degree of microstructural coarsening not readily possible with standard powder-processing approaches. This paper describes the consolidation results of titanium aluminide-based powder-composite materials. The focus of this study was the definition of microstructure/processing relationships for each of the composite constituents, first as monoliths and then in composite forms. Non-equilibrium phases present in rapidly solidified TiAl powders are transformed to metastable intermediates en route to the equilibrium gamma phase.

  2. 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

  3. 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.

  4. The structure-property relationships of powder processed Fe-Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Prichard, Paul D. [Iowa State Univ., Ames, IA (United States)

    1998-02-23

    Iron-aluminum alloys have been extensively evaluated as semi-continuous product such as sheet and bar, but have not been evaluated by net shape P/M processing techniques such as metal injection molding. The alloy compositions of iron-aluminum alloys have been optimized for room temperature ductility, but have limited high temperature strength. Hot extruded powder alloys in the Fe-Al-Si system have developed impressive mechanical properties, but the effects of sintering on mechanical properties have not been explored. This investigation evaluated three powder processed Fe-Al-Si alloys: Fe-15Al, Fe-15Al-2.8Si, Fe-15Al-5Si (atomic %). The powder alloys were produced with a high pressure gas atomization (HPGA) process to obtain a high fraction of metal injection molding (MIM) quality powder (D84 < 32 μm). The powders were consolidated either by P/M hot extrusion or by vacuum sintering. The extruded materials were near full density with grain sizes ranging from 30 to 50 μm. The vacuum sintering conditions produced samples with density ranging from 87% to 99% of theoretical density, with an average grain size ranging from 26 μm to 104 μm. Mechanical property testing was conducted on both extruded and sintered material using a small punch test. Tensile tests were conducted on extruded bar for comparison with the punch test data. Punch tests were conducted from 25 to 550 C to determine the yield strength, and fracture energy for each alloy as a function of processing condition. The ductile to brittle transition temperature (DBTT) was observed to increase with an increasing silicon content. The Fe-15Al-2.8Si alloy was selected for more extensive testing due to the combination of high temperature strength and low temperature toughness due to the two phase α + DO3 structure. This investigation provided a framework for understanding the effects of silicon in powder processing and mechanical property behavior of Fe-Al-Si alloys.

  5. Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy.

    Science.gov (United States)

    Colić, Miodrag; Rudolf, Rebeka; Stamenković, Dragoslav; Anzel, Ivan; Vucević, Dragana; Jenko, Monika; Lazić, Vojkan; Lojen, Gorazd

    2010-01-01

    Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.

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

    International Nuclear Information System (INIS)

    Kovarik, L.; Miller, M.K.; Court, S.A.; Mills, M.J.

    2006-01-01

    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) S //(0 1 4) Al S-phase/matrix interface, which is shown to coexist with the more commonly reported (0 0 1) S //(0 2 1) Al interface. This new (0 2 1) S //(0 1 4) 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

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

    International Nuclear Information System (INIS)

    Fu Ying-Ying; Li Hong-Xuan; Ji Li; Liu Xiao-Hong; Zhou Hui-Di; Chen Jian-Min; Liu Liu

    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. (paper)

  8. Fricción interna en plomo de muy alta pureza (99,9999% a temperaturas medias

    Directory of Open Access Journals (Sweden)

    Gallego, I.

    2001-04-01

    Full Text Available Internal friction spectra of high purity lead (99.9999% at medium temperatures exhibit a main relaxation peak at 230 K (P1 which depends strongly on the dislocation arrangement. The mechanism associated to P1 relaxation has an activation area between 500b2 and 2000b2 and its activation energy is 0.65±0.05 eV (63±5 KJ/mol, which is only 0,6 times the autodiffusion energy of lead. The behaviour of P1 peak and its dependence on thermomechanical treatments has allowed us to conclude that it is associated to the sliding of dislocations controlled by the climbing of jogs by diffusion of vacancies along the dislocation lines. At a slightly higher temperature, another relaxation (P1 turns up in the spectra, which can be associated to different mechanisms.

    El espectro de fricción interna, a medias temperaturas, del plomo de muy alta pureza (99,9999% presenta una relajación principal a 230 K (P1, cuya intensidad depende fuertemente del estado de organización de las dislocaciones. La medida de los parámetros de activación de P1 indica que el mecanismo asociado a esta relajación tiene un área de activación comprendida entre 500b2 y 2.000b2 y un valor de la energía de activación de 0,65 ±0,05 eV (63±5 KJ/mol, que es sólo 0,6 veces la energía de autodifusión del plomo. El comportamiento de esta relajación y su dependencia con los tratamientos termomecánicos, nos ha permitido concluir que P1 está originado por el deslizamiento de dislocaciones controlado por la escalada de escalones a lo largo de la línea de dislocación. A temperaturas ligeramente superiores, aparece otra relajación (P1, cuyo origen puede estar ligado a diferentes mecanismos.

  9. The Relationship between Virtue and Happiness in Aristotle and Al-Fārābī’s Views

    Directory of Open Access Journals (Sweden)

    Ali Sabri

    2016-09-01

    Full Text Available Throughout the history, different schools including both descriptive and non-descriptive ones, have been concerned with revealing relationship between happiness and virtue. As the First and Second teachers, Aristotle and Al-Fārābī can be named as having very important roles in this sense. So, the main tenet of ethics for these two philosophers is happiness, which is mostly derived from virtue. Considering theories of these two philosophers, it became evident that Aristotle had significant effects on Islamic thinkers. In other words, they claim they have been strongly influenced by Aristotle’s ideas. An obvious example for this can be ‘Nicomachean Ethics’ which attracted the attention of both western and eastern thinkers. As the greatest and the most salient commentator, Al-Fārābī could elaborate on Aristotle’s ideas on ethics and so suggest a comprehensive theory of ultimate happiness and Utopia' ('al-madīnat al-fāḍilah'. On the other hand, following Aristotle, Al-Fārābī divided ethics into two theoretical and practical branches. Hence, basis of ethical theories introduced by the two of these philosophers is based on happiness; However, Al-Fārābī added notions of Islam and mysticism to happiness. The most straightforward definition that Aristotle offers for happiness concerns an ultimate goal which humans are eagerly seeking to acquire it. He considers the best life as a happy life which can be reached by reasoning about humans’ actions and reactions and through adopting a viewpoint. In this sense, Aristotle introduced three types of lives, namely life with pleasure, political life, and life with intellect; he knows the third type of life better and more sublime than the other two. In his book on ethics, Aristotle defined happiness as soul’s performance according to perfect virtue. Regarding soul, Aristotle divided virtues into moral and rational ones. He believed that virtue is inasmuch as its genus is a hexis (habit

  10. SIMULACIÓN MATEMÁTICA PARA EVALUAR LA EFICIENCIA EN UN REACTOR PARA RECICLADO DE PLOMO

    Directory of Open Access Journals (Sweden)

    Pedro Vite-Martínez

    2010-01-01

    Full Text Available En este trabajo, se desarrolla un estudio por simulación matemática para un baño agitado por un sistema de aspas planas simples, el cual es utilizado en el proceso de separación de plomo líquido. En este proceso, se realiza una inyección de trazador en diversos puntos axiales del baño. Se analiza la hidrodinámica del baño, las curvas de edades y tiempos de residencia resultantes en cada punto de inyección y de monitoreo, con el fin de obtener el mejor de los puntos de inyección sin tener que variar la geometría original del baño. Para mejorar la eficiencia del mezclado se analizan los perfiles de velocidades y concentración obtenidas para identificar zonas muertas y de poca recirculación. Los puntos de monitoreo para la inyección de trazador se consideran suficientes para obtener una dinámica apropiada de la homogenización del baño para fines de análisis.

  11. Mechanical Properties and Melt Quality Relationship of Sr-modified Al-12Si Alloy

    Directory of Open Access Journals (Sweden)

    Uludağa M.

    2015-12-01

    Full Text Available The formation of oxide film on the surface of aluminium melts, i.e. bifilms, are known to be detrimental when they are incorporated into the cast part. These defects causes premature fractures under stress, or aid porosity formation. In this work, Al-12 Si alloy was used to cast a step mould under two conditions: as-received and degassed. In addition, 10 ppi filters were used in the mould in order to prevent bifilm intrusion into the cast part. Reduced pressure test samples were collected for bifilm index measurements. Samples were machined into standard bars for tensile testing. It was found that there was a good agreement with the bifilm index and mechanical properties.

  12. Microstructure-property relationships in Al-Cu-Li-Ag-Mg Weldalite (tm) alloys, part 2

    Science.gov (United States)

    Langan, T. J.; Pickens, J. R.

    1991-01-01

    The microstructure and mechanical properties of the ultrahigh strength Al-Cu-Li-Ag-Mg alloy, Weldalite (tm) 049, were studied. Specifically, the microstructural features along with tensile strength, weldability, Young's modulus and fracture toughness were studied for Weldalite (tm) 049 type alloys with Li contents ranging from 1.3 to 1.9 wt. pct. The tensile properties of Weldalite 049 and Weldalite 049 reinforced with TiB2 particles fabricated using the XD (tm) process were also evaluated at cryogenic, room, and elevated temperatures. In addition, an experimental alloy, similar in composition to Weldalite 049 but without the Ag+Mg, was fabricated. The microstructure of this alloy was compared with that of Weldalite 049 in the T6 condition to assess the effect of Ag+Mg on nucleation of strengthening phases in the absence of cold work.

  13. Alteraciones bioquímicas, hematológicas y de distribución y acumulación de plomo en un modelo animal y en humanos

    OpenAIRE

    Ventimiglia, Fernando Daniel

    2014-01-01

    El Plomo es un metal que la humanidad ha utilizado desde la antigüedad para diversos fines, pero que conlleva un problema eco-toxicológico de gran importancia, siendo el principal tóxico metálico de la actualidad y de mayor importancia en la producción de enfermedad laboral por metales. El objetivo de esta tesis, fue evaluar el impacto del plomo sobre parámetros bioquímicos, hematológicos, diversos órganos blanco de los sistemas biológicos y esbozar un modelo animal de distribución ...

  14. Neurotoxicity and aggressiveness triggered by low-level lead in children: a review Neurotoxicidad y agresividad desencadenadas por bajos niveles de plomo en niños: una revisión

    Directory of Open Access Journals (Sweden)

    Kelly Polido Kaneshiro Olympio

    2009-09-01

    Full Text Available Lead-induced neurotoxicity acquired by low-level long-term exposure has special relevance for children. A plethora of recent reports has demonstrated a direct link between low-level lead exposure and deficits in the neurobehavioral-cognitive performance manifested from childhood through adolescence. In many studies, aggressiveness and delinquency have also been suggested as symptoms of lead poisoning. Several environmental, occupational and domestic sources of contaminant lead and consequent health risks are largely identified and understood, but the occurrences of lead poisoning remain numerous. There is an urgent need for public health policies to prevent lead poisoning so as to reduce individual and societal damages and losses. In this paper we describe unsuspected sources of contaminant lead, discuss the economic losses and urban violence possibly associated with lead contamination and review the molecular basis of lead-induced neurotoxicity, emphasizing its effects on the social behavior, delinquency and IQ of children and adolescents.La neurotoxicidad adquirida inducida por la exposición prolongada a bajos niveles de plomo tiene una importancia especial en los niños. Una plétora de publicaciones recientes ha demostrado el vínculo directo existente entre la exposición a bajos niveles de plomo y el déficit en el desempeño neuroconductual-cognitivo manifestado desde la infancia hasta el final de la adolescencia. En numerosos estudios, la agresividad y la delincuencia juvenil también se han considerado síntomas de la intoxicación por plomo. Se han identificado y explicado ampliamente varias fuentes ambientales, laborales y domésticas de contaminación por plomo y los riesgos resultantes para la salud, pero aún son numerosos los casos de intoxicación por plomo. Se necesitan urgentes políticas de salud pública para prevenir la intoxicación por plomo de manera de reducir los daños y las pérdidas, tanto individuales como para la

  15. New insights in the structure-luminescence relationship of Eu:SrAl2O4

    International Nuclear Information System (INIS)

    Cordoncillo, Eloisa; Julian-Lopez, Beatriz; Martinez, Marta; Sanjuan, Maria Luisa; Escribano, Purificacion

    2009-01-01

    This work aims the preparation of Eu:SrAl 2 O 4 through a sol-gel methodology. Some studies point out the possibility that hexagonal polymorph exhibit higher luminescence efficiency than the monoclinic one. However, the slow diffusion processes in the solid-state reactions require the use of fluxing agents, like B(III) ions, to reduce the synthesis temperature, thus favouring the formation of the monoclinic phase and avoiding the stabilization of the hexagonal one. For that, the synthesis proposed in this work allows to prepare pure hexagonal and monoclinic polymorphs without the use of any fluxing agent. The influence of Eu-doping level and firing temperature in the crystalline structure and optical properties of both polymorphs are studied by means of X-ray diffraction, Raman scattering, absorption, excitation and emission spectroscopy. Emission spectra reveal the existence of energy transfer between the monoclinic matrix and the Eu 2+ ion, but the luminescence efficiency is not influenced by the crystalline polymorph but it mainly depends on the firing temperature.

  16. Die Kundenzufriedenheit als wesentliche Erfolgskomponente für das Customer-Relationship-Management im Hochschulbereich

    Directory of Open Access Journals (Sweden)

    Frank Nockermann

    2013-11-01

    Full Text Available Purpose: Today, not enough importance is being attached to Customer Relationship Management (CRM in tertiary education. Often interest groups, such as current and former students (alumni or various business organisations, are not sufficiently involved in any kind of network, with the result that there is no chance of a partnership developing with universities regarding lifelong learning. The main purpose of the article is to reveal that customer satisfaction is a determining factor in CRM in tertiary education. Scientific aim: The main scientific aim is to reveal that the theory of customer satisfaction can be employed to the marketing concept in tertiary education in practice. Methodology/methods: After outlining the principal theories of customer satisfaction this thesis concentrates on the more practical aspects of the topic. The main theory is the traditional Confirmations/Disconfirmations-Paradigm. It explains the customer relationship as a dependent and as an independent variable. Findings: The most important result is that it is possible to transfer the theoretical considerations into a practical CRM-concept for the tertiary education. Conclusions: The keynote of the model of Customer Satisfaction is contagious into a feasible marketing concept of universities. The different theories are various significant for practice. The main task will be to get as much as possible relevant information about the expectations, the satisfaction and the reactions of the different interest groups of the tertiary education respectively universities. This information is the database for a successful networking and CRM.

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

    OpenAIRE

    Ceto Nicholas

    2003-01-01

    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 recic...

  18. Determinación de los niveles de plomo y cadmio en leche procesada en la ciudad de Bogotá D.C.

    OpenAIRE

    Pinzon Choque, Carlos Giovanni

    2015-01-01

    La leche y los productos lácteos han sido reconocidos en todo el mundo por su influencia beneficiosa sobre la salud humana. Los niveles de metales en concentraciones tóxicas son un componente importante de la seguridad y la calidad de la leche. Se desarrolló un método sencillo de extracción (digestión) asistida por microondas para la determinación posterior de los niveles de cadmio (Cd) y plomo (Pb) en leche líquida por espectrofotometría de absorción atómica (AAE) con horno de grafito. Se ap...

  19. Relationships between microstructure and mechanical properties of Ti-5Al-5Mo-5V-3Cr-1Zr alloy

    Science.gov (United States)

    Li, Z. Y.; Wu, G. Q.; Huang, Z.

    2018-03-01

    Through a statistical, quantitative analysis on microstructure of Ti-5Al-5Mo-5V-3Cr-1Zr (Ti55531) alloy, the relationships between microstructure and mechanical properties and heat treatment temperatures were investigated. The results show that in Widmanstätten structure, the size of β grain is greatly increased with increasing annealing temperature. Static toughness is related to grain boundary alpha phase discontinuity, the tensile strength is related to acicular alpha phase interface length and acicular alpha phase proportion. In duplex microstructure, the tensile strength is related to the equiaxed alpha proportion. Elongation, static toughness and crack forming work are related to the equiaxed alpha proportion and negatively related to secondary phase proportion. The microstructure can be described quantitatively and the mechanical properties can be predicted by analysis of microstructure.

  20. 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

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

    Directory of Open Access Journals (Sweden)

    Sadi Haji

    2013-10-01

    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

  2. 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 %.

  3. El sistema geográfico de información y las concentraciones de plomo en sangre en una población infantil venezolana Usefulness of the Geographic Information System (GIS in the identification of contributing factors to lead blood concentrations in a population of Venezuelan children

    Directory of Open Access Journals (Sweden)

    Carlos Espinosa

    2006-04-01

    Full Text Available OBJETIVO: Identificar los factores ambientales que contribuyen a la concentración de plomo en sangre (Pb-S en niños de Valencia, Venezuela, con la utilización del Sistema Geográfico de Información (SGI. MATERIAL Y MÉTODOS: Estudio analítico ecológico. Población: 60 niños. Información obtenida: demografía, fuentes de emisión de plomo ambiental, niveles de Pb-S. Relación entre variables ambientales y Pb-S mediante análisis de buffer. RESULTADOS: Diferencia significativa entre el Pb-S en varones (11.1±3.1 µg/dl en comparación con las mujeres (9.5±2.7 µg/dl. La media de la Pb-S de los niños residentes en buffer (10.7±3.2 µg/dl fue superior a la media de los restantes (9.9±2.5 µg/dl. Los niños con valores superiores al límite permisible de Pb-S que viven en la zona sur tuvieron una media de Pb-S significativamente superior respecto de los demás. El SGI permitió identificar en el taller de herrería/soldadura la fuente de exposición más cercana a las residencias de los varones. CONCLUSIONES: El SGI hizo posible reconocer fuentes de exposición al plomo y su vínculo con niveles de Pb-S de los niños que viven cerca de dichas fuentes. Se sugiere evaluar con posterioridad los factores adicionales que favorecen el riesgo de exposición.OBJECTIVE: To identify environmental factors that contribute to blood lead levels (BPb in children living in an urban area in Valencia, Venezuela, using a Geographical Information System (GIS as an association tool. MATERIAL AND METHODS: An analytical-ecological study was carried out. Population: 60 children. Data collected: Demography, potential sources of environmental lead and BPb concentrations. An association was made between environmental variables and BPb, using a buffer analysis. RESULTS: There was a statistically significant difference between BPb in males (11.1±3.1 µg/dl compared to females (9.5±2.7 µg/dl. Average BPb of children living within the buffer areas (10.7±3.2 µg

  4. Structure–activity relationships of Pt/Al2O3 catalysts for CO and NO oxidation at diesel exhaust conditions

    DEFF Research Database (Denmark)

    Boubnov, Alexey; Dahl, Søren; Johnson, Erik

    2012-01-01

    Structure–performance relationships for Pt/Al2O3 catalysts with mean Pt particle sizes of 1, 2, 3, 5 and 10nm are investigated for the catalytic oxidation of CO and NO under lean-burning diesel exhaust conditions. The most active catalysts for CO oxidation exhibit Pt particles of 2–3nm, having a ...

  5. The Relationship between Cognitive Dissonance and Decision-Making Styles in a Sample of Female Students at the University of Umm Al Qura

    Science.gov (United States)

    Allahyani, Mariam Hameed Ahmed

    2012-01-01

    The aim of this study is to determine the magnitude of cognitive dissonance present in a sample of female students at Umm Al Qura University, and clarifying the relationship between the cognitive dissonance and decision-making styles. It also aimed to identify differences between female students with high cognitive dissonance and those with low…

  6. Estudio electrofisiológico de la funcion neuromuscular en una poblacion intoxicada con plomo

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    O. M. Genovese

    1988-03-01

    Full Text Available Un grupo de 12 pacientes con cifras elevadas de plombemia y disminuidas de ALA D fueron estudiados electrofisiológicamente. Se efectuaron las siguientes determinaciones: amplitud de potencial evocado muscular; latencia distal motora; velocidad de conducción motora en los nervios mediano, ciático poplíteo externo y radial; velocidad de conducción sensitiva y amplitud del potencial evocado sensitivo de nervio en el mediano; exploración electromiográfica convencional; estudio de la transmisión neuromuscular, mediante estimulación repetitiva del nervio ciático popliteo externo a diversas frecuencias, con registro de la amplitud del potencial en músculo tibial anterior. Los datos obtenidos fueron comparados con controles. Se buscaron correlaciones entre las determinaciones bioquímicas y los diferentes hallazgos electrofisiológicos que a su vez se correlacionaron entre si y también con el tiempo de evolución de la intoxicación. Los hallazgos pusieron de manifiesto la presencia de neuropatía axonal junto a moderada desmielinización. La exploración de la transmisión neuromuscular mostró ocasional decremento o incremento de la amplitud del potencial muscular evocado, hechos que suponen cierta participación de la unión neuromuscular. Se halló correlación solamente entre disminución de ALA D y la disminución de las amplitudes del potencial sensitivo del mediano y el evocado muscular del mismo nervio y con la disminución de la VCM del nervio radial. Una débil relación se observó entre el tiempo de exposición y la disminución de la VCS del nervio mediano y VCM del radial. Las determinaciones bioquímicas y el tiempo de exposición transcurridos no probaron ser parámetros sensibles para determinar el grado de afectación del sistema nervioso periférico. El conjunto do hallazgos sugiere que el desarrollo de la neuropatía puede estar ligado a factores individuales de predisposición al daño nervioso.

  7. Síntesis y caracterización de materiales nanométricos para su aplicación en baterías recargables de ión litio y plomo-ácido

    OpenAIRE

    Caballero, Álvaro

    2011-01-01

    La Tesis Doctoral "Síntesis y caracterizaicón de materiales nanométricos para su aplicación en baterías recargables de ión-litio y plomo-ácido" se enmarca dentro del creciente interés en la investigación sobre nanomateriales y nanotecnología. En el desarrollo de la memoria se presenta el estudio materiales nanoestructurados para su aplicación en electrodos positivos en las dos tecnologías de acumuladores de mayor mercado mundial. Para el caso de baterías de plomo-ácido, se evalúa la preparaci...

  8. 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.

  9. 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

  10. Phase relationships and stability of the {mu}- and {zeta}-phases in the Ag-Al-X (X=Zn, Ga, Ge) systems

    Energy Technology Data Exchange (ETDEWEB)

    Paruchuri, M.R.; Massalaski, T.B. [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering

    1993-09-01

    Details of phase relationships in three ternary systems, Ag-Al-X (X=Zn, Ga, Ge) near the Ag-rich corner at 400C are presented. Metallography, X-ray diffraction, scanning electron microscopy and X-ray spectroscopy have been used to establish the respective isothermal sections at 400C. In each case, the {mu}-phase and the {zeta}-phase of the Ag-Al binary system extend into the ternary system and terminate at a three-phase region involving the Ag-rich primary solid solution ({alpha}{sub 1}-phase) in the Ag-Al-Zn and Ag-Al-Ga systems, and the Ge-rich primary solid solution ({alpha}{sub 2}-phase) in the Ag-Al-Ge ternary system. The stability ranges of the {mu} and {zeta}-phases follow approximately constant electron concentration lines. The solid solubilities of Zn, Ga and Ge in the {mu}-phase are relatively small, compared with those in the {zeta}-phase (up to 18 at. %). No ternary phase appears to exist in the Ag-rich portions studied in the three ternary systems.

  11. 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

  12. 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

  13. 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

  14. [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.

  15. New Insights into c-Ret Signalling Pathway in the Enteric Nervous System and Its Relationship with ALS

    Directory of Open Access Journals (Sweden)

    M. J. Luesma

    2014-01-01

    Full Text Available The receptor tyrosine kinase Ret (c-Ret transduces the glial cell line-derived neurotrophic factor (GDNF signal, one of the neurotrophic factors related to the degeneration process or the regeneration activity of motor neurons in amyotrophic lateral sclerosis (ALS. The phosphorylation of several tyrosine residues of c-Ret seems to be altered in ALS. c-Ret is expressed in motor neurons and in the enteric nervous system (ENS during the embryonic period. The characteristics of the ENS allow using it as model for central nervous system (CNS study and being potentially useful for the research of human neurological diseases such as ALS. The aim of the present study was to investigate the cellular localization and quantitative evaluation of marker c-Ret in the adult human gut. To assess the nature of c-Ret positive cells, we performed colocalization with specific markers of cells that typically are located in the enteric ganglia. The colocalization of PGP9.5 and c-Ret was preferentially intense in enteric neurons with oval morphology and mostly peripherally localized in the ganglion, so we concluded that the c-Ret receptor is expressed by a specific subtype of enteric neurons in the mature human ENS of the gut. The functional significance of these c-Ret positive neurons is discussed.

  16. New insights into c-Ret signalling pathway in the enteric nervous system and its relationship with ALS.

    Science.gov (United States)

    Luesma, M J; Cantarero, I; Álvarez-Dotu, J M; Santander, S; Junquera, C

    2014-01-01

    The receptor tyrosine kinase Ret (c-Ret) transduces the glial cell line-derived neurotrophic factor (GDNF) signal, one of the neurotrophic factors related to the degeneration process or the regeneration activity of motor neurons in amyotrophic lateral sclerosis (ALS). The phosphorylation of several tyrosine residues of c-Ret seems to be altered in ALS. c-Ret is expressed in motor neurons and in the enteric nervous system (ENS) during the embryonic period. The characteristics of the ENS allow using it as model for central nervous system (CNS) study and being potentially useful for the research of human neurological diseases such as ALS. The aim of the present study was to investigate the cellular localization and quantitative evaluation of marker c-Ret in the adult human gut. To assess the nature of c-Ret positive cells, we performed colocalization with specific markers of cells that typically are located in the enteric ganglia. The colocalization of PGP9.5 and c-Ret was preferentially intense in enteric neurons with oval morphology and mostly peripherally localized in the ganglion, so we concluded that the c-Ret receptor is expressed by a specific subtype of enteric neurons in the mature human ENS of the gut. The functional significance of these c-Ret positive neurons is discussed.

  17. New Insights into c-Ret Signalling Pathway in the Enteric Nervous System and Its Relationship with ALS

    Science.gov (United States)

    Luesma, M. J.; Cantarero, I.; Álvarez-Dotu, J. M.; Santander, S.; Junquera, C.

    2014-01-01

    The receptor tyrosine kinase Ret (c-Ret) transduces the glial cell line-derived neurotrophic factor (GDNF) signal, one of the neurotrophic factors related to the degeneration process or the regeneration activity of motor neurons in amyotrophic lateral sclerosis (ALS). The phosphorylation of several tyrosine residues of c-Ret seems to be altered in ALS. c-Ret is expressed in motor neurons and in the enteric nervous system (ENS) during the embryonic period. The characteristics of the ENS allow using it as model for central nervous system (CNS) study and being potentially useful for the research of human neurological diseases such as ALS. The aim of the present study was to investigate the cellular localization and quantitative evaluation of marker c-Ret in the adult human gut. To assess the nature of c-Ret positive cells, we performed colocalization with specific markers of cells that typically are located in the enteric ganglia. The colocalization of PGP9.5 and c-Ret was preferentially intense in enteric neurons with oval morphology and mostly peripherally localized in the ganglion, so we concluded that the c-Ret receptor is expressed by a specific subtype of enteric neurons in the mature human ENS of the gut. The functional significance of these c-Ret positive neurons is discussed. PMID:24868525

  18. 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%

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. Relationship between nurse's general health and their personal occupational traits in Al-Zahra Hospital of Isfahan, 2015

    Directory of Open Access Journals (Sweden)

    Mahnaz Adibi

    2016-11-01

    Full Text Available Health state is one of the most important factors in their life. Individuals may be subject to threatening factors in different ways. Nurses are one main group of community whose health may be threatened due to their occupational environment. Therefore, this study aimed at investigating general health of nurses and their personal occupational traits. Method: This study is correlation-descriptive research. Statistical population consists of 220 nurses working in Al-Zahra hospital selected by random sampling. Instrument of this study includes a demographic questionnaire and a standard Goldberg 28-question questionnaire. The data were analyzed by SPSS software. Findings: in this study, nurses are subject to occupational events, physical and chemical harmful materials, biologic harmful materials, mental/ ergonomic harmful occupational factors. And there exists relation between their general health and their age, number of children and marital status. But no relation has been seen with their surgery records, rate of sport they do, vaccination, the unit in which they work, their occupational environment, their occupational record and posts.

  4. Microstructure-mechanical property relationships for Al-Cu-Li-Zr alloys with minor additions of cadmium, indium or tin

    Science.gov (United States)

    Blackburn, L. B.; Starke, E. A., Jr.

    1989-01-01

    Minor amounts of cadmium, indium or tin were added to a baseline alloy with the nominal composition of Al-2.4Cu-2.4Li-0.15Zr. These elements were added in an attempt to increase the age-hardening response of the material such that high strengths could be achieved through heat-treatment alone, without the need for intermediate mechanical working. The alloy variant containing indium achieved a higher peak hardness in comparison to the other alloy variations, including the baseline material, when aged at temperatures ranging from 160 C to 190 C. Tensile tests on specimens peak-aged at 160 indicated the yield strength of the indium-bearing alloy increased by approximately 15 percent compared to that of the peak-aged baseline alloy. In addition, the yield strength obtained in the indium-bearing alloy was comparable to that reported for similar baseline material subjected to a 6 percent stretch prior to peak-aging at 190 C. The higher strength levels obtaied for the indium-bearing alloy are attributed to increased number densities and homogeneity of both the T1 and theta-prime phases, as determined by TEM studies.

  5. Processing/microstructure/mechanical-property relationships in FeAlZrB with and without an oxide dispersion

    International Nuclear Information System (INIS)

    Strothers, S.D.H.

    1991-01-01

    The effect of powder and processing variables on the microstructure of an extruded FeAlZrB alloy was investigated. Results shows that key parameters in microstructural development are extrusion temperature and powder particle size. In addition to powder and processing variables, the effect of a 1 vol% Y 2 O 3 dispersion was investigated. The microstructure of this material was very fine-grained. By manipulating powder and processing parameters and heat treatments, a very large range of microstructures were obtained. This enabled an evaluation of the role of microstructure and grain size on the room-temperature and elevated-temperature mechanical behavior of this alloy. At 1,100K the coarse-grained materials exhibited larger yield strengths in tension with the exception of the very-fine-grained oxide-dispersion-strengthened extrusions. These had the highest yields strengths despite their fine grain sizes. The oxide-dispersion-strengthened alloys also showed the greatest compression creep resistance at 1,100K even when heat treated to large grain sizes

  6. 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

  7. 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

  8. 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.  

  9. CONTENIDO Y TRASLOCACIÓN DE PLOMO EN AVENA (Avena sativa, L. Y HABA (Vicia faba, L. DE UN SUELO CONTAMINADO

    Directory of Open Access Journals (Sweden)

    Elizabeth García-Gallegos

    2011-01-01

    Full Text Available Un experimento en invernadero se estableció para determinar la concentración de plomo (Pb en suelo, raíz y parte aérea de haba y avena; se calculó el factor de bioconcentración y traslocación en las dos especies. Se probaron 50, 100 y 150 mg·Pb·kg-1 de suelo, incluyendo un control. Las plantas se colectaron a los 60 días después de la siembra y se midieron altura de planta (AP, volumen radical (VR y biomasa seca total (BST, además del contenido de Pb en suelo, raíz y parte aérea. La cuantificación de Pb se realizó por espectrofotometría de absorción atómica. El suelo cultivado con haba presentó un 28.48 % de PbEDTA. Las variables AP, VR y BST no fueron afectadas de manera drástica por las concentraciones de Pb probadas. Las plantas de haba y avena absorbieron un total de 55 mg·kg-1 y 45.3 mg·kg-1, respectivamente, las cuales se consideran tóxicas para plantas cultivadas. Los resultados pueden servir de base para ampliar el conocimiento del contenido de Pb absorbido y traslocado en plantas de haba y avena, ya que la capacidad de tolerar y absorber Pb es específica de la especie, inclusive de la variedad de planta.

  10. 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

  11. 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.

    Science.gov (United States)

    Hemati, Zeinab; Kiani, Davood

    2016-04-01

    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. This was a descriptive-analytical study on 64 patients with ITP who referred to Isfahan's Sayed Al-Shohada Hospital, Iran. In this study, patients with ITP were selected randomly using a random number chart. The data collection tools consisted of the World Health Organization Quality of Life (WHOQOL)-BREF and Coopersmith Self-esteem Inventory (CSEI). Data were analyzed using SPSS and chi-square and Mann-Whitney tests and the Pearson and Spearman's rank correlation coefficients. In total, 64 patients completed the questionnaires. RESULTS showed that 32% of subjects were over 36 years of age and 59% were women. In addition, 29.7% of ITP patients had low self-esteem and quality of life. Chi-square test showed a significant relationship between self-esteem and quality of life of patients with ITP. The results of the present study showed that considerable attention must be paid to self-esteem, as one of the most important factors influencing the promotion of quality of life. Therefore, it is suggested that patient's self-esteem be improved by the implementation of educational and psychological programs in order to decrease the consequences of poor quality of life.

  12. Relationship of squamosal suture to asterion on external skull surfaces versus endocasts of pongids: implications for Hadar early hominid AL 162-28.

    Science.gov (United States)

    Falk, D; Hildebolt, C; Vannier, M

    1994-04-01

    The relationship between the squamosal suture and asterion was quantified in 15 hemispheres of eight chimpanzee endocasts that were aligned in the conventional lateral view (i.e., with frontal pole [FP]-occipital pole [OP] horizontal). Using a three-dimensional digitizer, x, y, and z coordinates were collected for the highest and lowest points of the squamosal suture, and the most rostral point of the suture approximate to the coronal suture. Our results were compared to a similar study of the squamosal suture on the external surfaces of chimpanzee skulls that were oriented in the Frankfurt horizontal (Holloway and Shapiro, 1992). The relationship between the squamosal suture and asterion differs markedly between the outsides of skulls and endocasts. Whereas the squamosal suture is very rarely below asterion on the external skull, we found that most of the squamosal suture is located inferior to asterion on endocasts. We also found that the squamosal suture courses approximately 2.0 mm lower on the right side than the left. (An asymmetry of the same magnitude was reported for the external skull but, curiously, in the opposite direction.) It may be that a lowered right squamosal endosuture on chimpanzee endocasts is associated with earlier closure on that side. The discrepancy in results for the external skull versus endocast is partially attributable to orienting chimpanzee skulls in the Frankfurt horizontal, which usually results in the endocasts being tilted so that FP is above OP, i.e., FP-OP is not parallel with the Frankfurt horizontal. Falk's (1985) orientation of the early hominid endocast from Hadar (AL 162-28) is consistent with data determined from endocasts of chimpanzees.

  13. 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

  14. Development of constitutive relationship and processing map for Al-6.65Si-0.44Mg alloy and its composite with B{sub 4}C particulates

    Energy Technology Data Exchange (ETDEWEB)

    Gangolu, S. [Department of Mechanical Engineering, School of Technology, GITAM University, Hyderabad 502329 (India); Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Gourav Rao, A. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Naval Materials Research Laboratory, ShilBadlapur Road, Addl. Ambernath (E), Dist.- Thane, 421506 (India); Sabirov, I. [IMDEA Materials Institute, Getafe 28906, Madrid (Spain); Kashyap, B.P., E-mail: bpk@iitb.ac.in [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Prabhu, N. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076 (India); Deshmukh, V.P. [Naval Materials Research Laboratory, ShilBadlapur Road, Addl. Ambernath (E), Dist.- Thane, 421506 (India)

    2016-02-08

    High temperature flow behavior of Al-6.65Si-0.44Mg (all in wt%) (A356) alloy and A356+5 wt% B{sub 4}C composite were investigated by compression test at temperatures 470, 500, 530 and 570 °C and strain rates 10{sup −3}, 10{sup −2}, 10{sup −1} and 1 s{sup −1}. Constitutive relationship was established by the prediction of materials constants α, β, n, Q and lnA. The variations in stable and instable regions of processing map were investigated in A356 alloy and A356+5 wt% B{sub 4}C composite. It was found that the existence of instability domain for A356 alloy, over the range of temperatures ~510–570 °C and strain rates ~1− 4×10{sup −2} s{sup −1}, was extended to regime of temperatures ~470–570 °C over the same strain rates upon 5% B{sub 4}C reinforcement. The microstructural evolutions by stable and instable regions were studied in scanning electron microscope (SEM) and by the electron backscatter diffraction (EBSD) technique.

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

    OpenAIRE

    Samanta Andrea Martínez; Liliana Marina Cancela; Miriam Beatriz Virgolini

    2011-01-01

    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...

  16. ALS Association

    Science.gov (United States)

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

  17. Familial ALS

    Science.gov (United States)

    Boylan, Kevin

    2015-01-01

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

  18. Mineralogy and petrology of the Dar al Gani 476 martian meteorite: Implications for its cooling history and relationship to other shergottites

    Science.gov (United States)

    Mikouchi, Takashi; Miyamoto, Masamichi; McKay, Gordon A.

    2001-04-01

    Dar al Gani 476, the 13th martian meteorite, was recovered from the Sahara in 1998. It is a basaltic shergottitic rock composed of olivine megacrysts reaching 5 mm (24 vol%) set in a fine-grained groundmass of pyroxene (59 vol%) and maskelynitized plagioclase (12 vol%) with minor amounts of accessory phases (spinel, merrillite, ilmenite). Dar al Gani 476 is similar to lithology A of Elephant Moraine A79001 (EETA79001) in petrography and mineralogy, but is distinct in several aspects. Low-Ca pyroxenes in the Dar al Gani 476 groundmass are more magnesian (En76Fs21Wo3~En58Fs30Wo12) than those in lithology A of EETA79001 (En73Fs22Wo5~En45Fs43Wo12), rather similar to pyroxenes in lherzolitic martian meteorites (En76Fs21Wo3~En63Fs22Wo15). Dar al Gani 476 olivine is less magnesian and shows a narrower compositional range (Fo76-58) than EETA79001 olivine (Fo81-53), and is also similar to olivines in lherzolitic martian meteorites (Fo74-65). The orthopyroxene-olivine-chromite xenolith typical in the lithology A of EETA79001 is absent in Dar al Gani 476. It seems that Dar al Gani 476 crystallized from a slightly more primitive mafic magma than lithology A of EETA79001 and several phases (olivine, pyroxene, chromite, and ilmenite) in Dar al Gani 476 may have petrogenetic similarities to those of lherzolitic martian meteorites. Olivine megacrysts in Dar al Gani 476 are in disequilibrium with the bulk composition. The presence of fractured olivine grains in which the most Mg-rich parts are in contact with the groundmass suggests that little diffusive modification of original olivine compositions occurred during cooling. This observation enabled us to estimate the cooling rates of Dar al Gani 476 and EETA79001 olivines, giving similar cooling rates of 0.03-3 ?C/h for Dar al Gani 476 and 0.05-5 ?C/h for EETA79001. This suggests that they were cooled near the surface (burial depth shallower than about 3 m at most), probably in lava flows during crystallization of groundmass. As is

  19. 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…

  20. tHE RELAtIonsHIP BEtWEEn nAtIonAL WELL-BEInG AnD ...

    African Journals Online (AJOL)

    out at immigrants for their alleged role in fuelling unemployment and crime. The political discourses of ..... be contrasted with a reported NWI of 61.1 in Australia in 2007 (Cummins et al.,. 2009) and in Algeria of 46.5 in ..... Youth unemployment is considerably higher – slightly less than half (49.8%) of those willing to work in ...

  1. Relationships between the distribution of O atoms on partially oxidized metal (Al, Ag, Cu, Ti, Zr, Hf) surfaces and the adsorption energy: A density-functional theory study

    Science.gov (United States)

    Houska, J.; Kozak, T.

    2017-06-01

    We investigate the oxidation of selected metal (Al, Ag, Cu, Ti, Zr, and Hf) surfaces by the density functional theory. We go through a wide range of (233 per metal) distributions of O atoms on a partially oxidized metal surface. First, we focus on the qualitative information whether the preferred distribution of O atoms is heterogeneous (stoichiometric oxide + metal) or homogeneous (substoichiometric oxide). We find that the former is energetically preferred, e.g., for Al, while the latter is energetically preferred, e.g., for Ti, Zr, and Hf. Second, we provide the quantitative values of adsorption energies corresponding to the energetically preferred O atom distributions for various partial coverages of various metals by O. Third, we discuss and show an example of implications of the aforementioned findings for the understanding and simulations of sputtering.

  2. Ti, Al

    Indian Academy of Sciences (India)

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

  3. Response to Comment: RE: Ohlenforst et al. (2016) Exploring the Relationship Between Working Memory, Compressor Speed, and Background Noise Characteristics, Ear Hear 37, 137–143

    DEFF Research Database (Denmark)

    Ohlenforst, Barbara; Souza, Pamela E.; MacDonald, Ewen N.

    2017-01-01

    We appreciate the opportunity to respond to the comment on our study (Ohlenforst et al. 2016). The issue of concern to the letter writer, “The speech and the noise signals were separately compressed before the SNRs [signal-to-noise ratios] were computed based on the signal’s root mean square values.......” referred to a calibration process in which the compressor gain function, derived from the mixed signal, was applied separately to the speech signal and to the separate noise signals to quantify the output signal to noise ratio. This was done to investigate compressor functionality. However, to create...... the test stimuli presented to the participants, the compressor was applied to the mixed speech-plus-noise signal at a specified input signal to noise ratio (−4, −2, and 0 dB), not on the speech signal or the noise signals alone. That is, the actual stimulus processing was all done on the mixed speech-plus-noise...

  4. Relationship of light-output nonlinearities and light-output spikes in proton-bombarded stripe-geometry double-heterostructure (Al,Ga)As lasers

    International Nuclear Information System (INIS)

    Dixon, R.W.; Joyce, W.B.; Miller, R.C.

    1979-01-01

    By using a fast photodetector and a simple spatial filtering technique, the relationship between the optical spike which frequently appears at the leading edge of a pulsed-GaAs-laser response and the optical nonlinearities called kinks has been investigated. It is suggested that the spike can be viewed consistently as a transition period during which the lasing mode distortion, which has been previously associated with kinks, occurs. It is the time taken for the kink to become established. During the spike, light emisson occurs with a spatial and angular intensity distribution consistent with the lasing which would be appropriate if the kink did not exist. It is shown that the experimental technique can also be used to investigate sustained laser optical-intensity oscillations

  5. Checking the relationship between physicians' communication skills and outpatients' satisfaction in the clinics of Isfahan Al-Zahra(S) Hospital in 2011.

    Science.gov (United States)

    Rezaei, Fatemeh; Askari, Hedayat Allah

    2014-01-01

    The quality of communication skills of health care providers has a significant impact on patient treatment consequences. The present research has been conducted to check the relationship of communication skills on the rate of patients' satisfaction in the clinics of one of the hospitals in Isfahan. The checking list was completed by the researcher in the clinics by using the comments of patients or their relatives. Sampling was performed by using the regular random sampling method. This research was a descriptive-analytical study. The used tool was a standard checking list for evaluating the patients' satisfaction and also the researcher-made checking list for the measurement of effective communication skills. The researcher-made checking list for the measurement of effective communication skills was confirmed by the experts with the face validity, structure, content, and reliability (α =87%). After visiting the patient by the physician, the mentioned list was filled by using the patients' comments, and the collected data was analyzed by SPSS software version 16 with calculating the Pearson correlation coefficient and α2. The study showed that there was a significant relationship between the application of communication skills in the five areas of verbal, body language, effective communicating, establishment, patient privacy and patient participation, except for eye communication of the physician with patients' satisfaction (P communication skills by physicians is associated with patients' satisfaction, and it is the cause of increasing the acceptance of the physician by the patient. Therefore, it is suggested that the opportunity to improve the communication skills should be provided in addition to clinical skills in continuing education programs for the medical community.

  6. al junctions

    African Journals Online (AJOL)

    Preferred Customer

    Bruan and Heeger,. 1991), Schottky barrier devices (Gardner and Tan,. 1989; Bantikassegn Workalemahu and Inganas,. 1997; Granstrom et al., 1998), organic solar cells. (Abay Gadisa and ... the capacitance per unit area of the cell as well as.

  7. 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.

  8. Investigating the relationship between ageism and some demographic aspects in offering nursing care to elder patients of Al-zahra hospital, Isfahan

    Directory of Open Access Journals (Sweden)

    Bahareh Afarigan

    2016-12-01

    Full Text Available Objective and domain: patient care quality is influenced by many factors one of which can be nurse’s attitude toward the elderly. The present study conducted aiming at specifying the relationship between ageism and some demographic aspects of nursing care toward elder patients hospitalized at Alzahra hospital. Method: the present study is a co relational descriptive research. The statistical population includes all nurses who work in different units of Alzahra hospital of Isfahan (except those working in pediatric and NICU units, as they have no contact with elder patients in 2015. Through availability sampling 275 nurses were selected; 93 male and182 female nurses. Instrument of this study was a questionnaire on ageism designed by researcher. In order for analyzing the data, the researcher used independent T test, variance analysis test and Cross call Valise test. Findings: in investigating knowledge related to elder people, findings of this study shows that this knowledge was in a low level in 11.6 % of nurses and high in 32.7% of them. Attitudes toward elder patients were in 8.4%of nurses negative in 81.8% of them neuter and 9.8% of nurses have got positive attitudes toward the elderly. Also results demonstrated that this attitude was meaningfully more negative in male nurses than females. But in other aspects like age, educational level, income, educational time, ethnicity, living with elderly people and presence of an elder person in their family or relatives, no meaningful difference was seen. Discussion and conclusion: In general, this study showed that sex, occupational record, having passed educational term time are factors influencing ageism. But other demographic characteristics played no meaningful role in nurses’ ageism and these are to be paid more attention in order to decrease ageism.

  9. Prevalence of temporomandibular joint disorders in outpatients at Al-Badar Dental College and Hospital and its relationship to age, gender, occlusion and psychological factors

    Directory of Open Access Journals (Sweden)

    Raheel Ahmed Syed

    2012-01-01

    Full Text Available Background: Temporomandibular disorder (TMD is a collective term that encompasses many clinical problems involving the masticatory muscles, temporomandibular joints (TMJ and associated structures and it has high prevalence among populations. Aims and objectives: To determine the prevalence of TMD and its relationship to age, gender, occlusion and psychological factors and to evaluate which age group, gender, malocclusion parameters and psychological factors contribute to the prevalence of TMD. Materials and methods: The study includes a sample of 250 young adults (134 girls and 116 boys with age ranging from 18 to 25 years, the presence and severity of TMD was determined using a self-administered anamnestic questionnaire composed of 10 questions regarding common TMD symptoms. Morphologic occlusion was evaluated according to Angle′s classification (molar classes I, II, III and to evaluate the psychological factors, The hospital anxiety and depression scale (HADS developed by Zigmond and Snaith was used. Results: Data were computerized and the SPSS package (version 11.2 was used and nonparametric test of Chi-square for data analysis and unpaired t-test was also used for statistical data analysis. Anamnestic index (AI showed that the percentage of women (5522% had higher degree of TMD symptoms than compared with men (50.86%, comparing the age of men and women free TMD and with TMD, the statistical difference was not significant as (t = 1.35, p > 0.5, distribution of the cases among Angle′s class I, II, III occlusion the difference was not statistically significant as (p > 0.5, the degree of anxiety and TMD degree among men and women patients, women had higher anxiety levels as compared to men and no statistical difference was found between the cases of men and women in the depression levels. Conclusion: Prevalence of TMD symptoms in our sample of 250 patients was high for women- Morphologic occlusion was not associated with the presence of TMD

  10. et al

    African Journals Online (AJOL)

    Schalk Cloete

    experienced (Bath, 2006), while indications are that no new drenches are in the process of being developed. Existing strategies for the control of these pathogens are thus challenged (Bath, 2006), and alternative strategies need to be formulated (Vatta et al., 2000). A possible avenue for dealing with the challenge of ...

  11. 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

  12. 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

  13. 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

  14. Experimental study on the relationship between the mineral production capability and the physiochemical properties in the coproduction of Q phase-3CaO·3Al2O3·CaSO4 cement clinker.

    Science.gov (United States)

    He, Chao; Tian, Chaochao; Li, Gang; Mei, Yahe; Zhang, Quanguo; Jiao, Youzhou

    2018-01-01

    A coproduction tests of quaternary (Q) phase(6CaO·4Al2O3·MgO·SiO2) -3CaO·3Al2O3·CaSO4 cement clinker and an experimental study on the relationship between the mineral production capability and the physiochemical properties are conducted in a two-stage multiphase reaction test bed with Changguang coal. X-ray diffractometer (XRD) analyses are performed on the coproduction clinker samples. The results demonstrate that, with the reduction in particle sizes of the coal powder and the additives and expanded screening level differences between them, both the proportion of Q phase and the mass of 3CaO·3Al2O3·CaSO4 in the clinker increase accordingly. When mixed coal powder particles are prepared through reducing particle sizes and expanding screening level differences between coal powder and additives, the additives CaO and MgO are more likely to be enclosed by coal powder to form globular polymerized particles. In addition, this preparation aids in polymerization and promotes even distribution of CaO, MgO and coal minerals, thus facilitating clinker mineral formation reactions of inorganic substances in the mixed coal powder. Target minerals, such as 2CaO·SiO2 and Q phase, are found in both industrial high-calcium limestone and low-calcium limestone coproduction clinker samples. A diffraction peak of free CaO is also evident in both samples. Compared with a coproduction clinker sample of high-calcium limestone, that of low-calcium limestone exhibits higher diffraction peaks for 2CaO·SiO2 and Q phase. With the current state of the art, it is not yet the optimum choice to substitute CaCO3 for CaO in Q-phase cement clinker coproduction. Before the technology matures and gains practical application, further study on the form and the mixing process of calcium-based additives for cement clinker coproduction will be required.

  15. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... for Educators Search English Español Lou Gehrig's Disease (ALS) KidsHealth / For Kids / Lou Gehrig's Disease (ALS) What's ... with ALS in the 1930s. What Happens in ALS? ALS damages motor neurons in the brain and ...

  16. Producción y distribución de plata en la sociedad argárica y en los primeros asentamientos orientalizantes. Una aproximación desde el análisis de los isótopos de plomo

    OpenAIRE

    Murillo-Barroso, M.; Montero Ruiz, I.

    2014-01-01

    Dado el papel que pudo jugar la plata en los procesos de estratificación social tanto en la sociedad argárica del Sureste como en las sociedades del Bronce Final/Hierro I, especialmente del Suroeste de la Península Ibérica, en este artículo tratamos de aproximarnos a la organización de la producción de plata en ambas sociedades mediante el estudio de los isótopos de plomo. Se presenta una primera aproximación a los análisis isotópicos realizados sobre objetos de plata argáricos y ...

  17. BASURA ELECTRÓNICA: CUANDO EL PROGRESO ENFERMA AL FUTURO

    Directory of Open Access Journals (Sweden)

    Hernán Urbina Joiro

    2015-03-01

    Full Text Available Es una sombría paradoja que los aparatos que surgieron para apuntalar el futuro hayan empezado a enfermar al futuro mismo: madres embarazadas, niños y jóvenes en regiones vulnerables, como son la mayoría de regiones en el mundo. INTRODUCCIÓN Basura electrónica es todo desecho de un dispositivo diseñado para funcionar con energía eléctrica de redes públicas, baterías u otros campos electromagnéticos. También se conoce como Residuos de Aparatos Eléctricos y Electrónicos (RAEE o Waste Electrical (e-Waste (1. Los aparatos electrónicos funcionales, en estado íntegro, no son basura electrónica, ni fuentes activas de residuos peligrosos, que en ese estado de funcionabilidad están convenientemente empaquetados y en estado no dispersivo. Habría que destrozar e incinerar estos aparatos funcionales, tal como se hace en el reciclaje primitivo, para que sean liberados esos residuos peligrosos. ¿Qué son los residuos peligrosos –la gran amenaza que encarna la basura electrónica–? El Convenio de Basilea (2 establece que son residuos peligrosos, entre otros, los desechos que contengan retardantes de llama policlorados y polibromados; metales pesados como el cromo hexavalente, cadmio, plomo, mercurio, o cobre, también tóxicos derivados de la incineración como los dibenzofuranos y dibenzoparadioxinas –todos típicos de la basura electrónica– e incluso señala como residuo peligroso a la basura con montajes eléctricos y electrónicos –incluidos los cables eléctricos. De modo que toda basura electrónica contiene y genera residuos peligrosos y debe manejarse toda como tal: como basura peligrosa. Por ello la Directiva vigente de la Unión Europea sobre residuos eléctricos y electrónicos (3 exige que todos los aparatos eléctricos y electrónicos lleven un símbolo que impida que vayan al cesto de la basura.

  18. Phase relationships in the area of the beta aluminate of the system K{sub 2}O-MgO-AL{sub 2}O{sub 3}; Phasenbeziehungen im Bereich der Beta-Aluminate des Systems K{sub 2}O-MgO-Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kroon, P. de

    1996-12-01

    The aim of this work was to be able to make statements about the thermodynamic stability of K-{beta}``-Al{sub 2}O{sub 3} in the pseudo-binary system K{sub 2}O-Al{sub 2}O{sub 3} and in the pseudo-ternary system K{sub 2}O-MgO-Al{sub 2}O{sub 3} relative to the adjacent phases of KAlO{sub 2} {alpha}-Al{sub 2}O{sub 3}, MgAl{sub 2}O{sub 4} and K-{beta}-Al{sub 2}O{sub 3}. (orig./MM) [Deutsch] Ziel dieser Arbeit war es, Aussagen ueber die thermodynamische Stabilitaet von K-{beta}``-Al{sub 2}O{sub 3} im pseudobinaeren System K{sub 2}O-Al{sub 2}O{sub 3} und im pseudoternaeren System K{sub 2}O-MgO-Al{sub 2}O{sub 3} relativ zu den benachbarten Phasen KAlO{sub 2}, {alpha}-Al{sub 2}O{sub 3}, MgAl{sub 2}O{sub 4} und K-{beta}-Al{sub 2}O{sub 3} machen zu koennen. (orig./MM)

  19. 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

  20. 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

  1. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    opponents were the stringent militants in the Khaldan camp and its Institute of the Faith Brigades (Ma`had Kata`ib al-Iman), where the virulent ...local fighter remembered that al-Libi used to live together with Hamza al- Rabi `a, the former head of al-Qa`ida’s external operations, and Abu Khabbab

  2. Microstructural characterization of a rapidly solidified Al-5 Sb alloy

    International Nuclear Information System (INIS)

    Zhang Zhonghua; Bian Xiufang; Wang Yan

    2003-01-01

    In the present work, the microstructure of a melt-spun Al-5 Sb alloy has been characterized using X-ray diffraction and transmission electron microscopy. The phases present in the melt-spun Al-5 Sb alloy were determined to be the equilibrium α-Al and AlSb, identical to those in the ingot-cast alloy. The microstructure of the melt-spun Al-5 Sb alloy is composed of primary AlSb phase embedded in the matrix comprising α-Al cells with intercellular nanoscale AlSb particles, different from that of the ingot-cast alloy composed of the primary AlSb phase within an α-Al/AlSb eutectic matrix. Rapid solidification has a marked effect on the morphology, size and distribution of the primary AlSb phase in the melt-spun Al-5 Sb alloy. Furthermore, some orientation relationships were determined in the melt-spun alloy

  3. All About ALS

    Science.gov (United States)

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

  4. İşsizlik ile Sigara Üzerinden Alınan Vergiler Arasındaki İlişki: Türkiye Analizi(The Relationship Between Tobacco Tax and Unemployment: Turkey Analysis

    Directory of Open Access Journals (Sweden)

    Emrah GÜLAY

    2016-08-01

    Full Text Available There are a number of studies focusing on the relationship between the tobacco consumption and unemployment rate in Turkey. Therefore, this study contributes to the literature because the relationship between tobacco tax and unemployment rate has not been studied before. The objective of this study is to determine the relationship between the tobacco tax and unemployment rate in Turkey over the period 2006:1-2015:7. In this context, Unit root tests have been exploited to check the integration order of the variables, and the Autoregressive Distributed Lag Model including structural breaks is employed to explain the long-run relationship between the tobacco tax and unemployment rate. The findings of this study show that while an increase in unemployment rate is to raise tobacco tax in the long-run, an increase in unemployment rate is to decrease tobacco tax in the short-run.

  5. Abusive Relationships

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Abusive Relationships KidsHealth / For Teens / Abusive Relationships Print en español Relaciones de maltrato Healthy Relationships = Respect & Trust Healthy relationships involve respect, trust, and ...

  6. The Relationship between Cognitive Dissonance and the Big-5 Factors Model of the Personality and the Academic Achievement in a Sample of Female Students at the University of Umm Al-Qura

    Science.gov (United States)

    Al Otaibi, Sameera Moharib B.

    2012-01-01

    The aim of this study is to try to determine the relationship between the cognitive dissonance, the Big-Five Factors (neuroticism, extroversion, openness, agreeableness, and conscientiousness) and the academic achievement. The study also aim to identify differences between female students with high cognitive dissonance and students with low…

  7. /Cu-Al System

    Science.gov (United States)

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

    2014-05-01

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

  8. Aussprache als motorische Fertigkeit

    DEFF Research Database (Denmark)

    Bonner, Maria

    2013-01-01

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

  9. Genetic Testing for ALS

    Science.gov (United States)

    ... In Your Community Advocate Get Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic Counselor Familial ALS Most of the time ALS is not inherited. ...

  10. Initial Symptoms of ALS

    Science.gov (United States)

    ... Chapters Certified Centers and Clinics Support Groups About ALS About Us Our Research In Your Community Advocate ... Diagnosis En español Symptoms The initial symptoms of ALS can be quite varied in different people. One ...

  11. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    ... cognitive problems involving word fluency, decision-making, and memory. Most cases of ALS happen ... and edaravone have approved by the Food and Drug Administration (FDA) to treat ALS. Riluzole ...

  12. 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

  13. Amyotrophic lateral sclerosis (ALS)

    Science.gov (United States)

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

  14. Abiodun et al (19)

    African Journals Online (AJOL)

    DELL

    2018-03-01

    Mar 1, 2018 ... carboxymethylation) and enzymatic technique. (Abbas et al., 2010; Jyothi et al., 2013). Modification of other starches from corn, cassava, potato and some yam ..... release of water from the polymeric network. (syneresis). The water thus released leaves the starch gel with a sponge-like texture. Abiodun et al.

  15. Microstructural characterization of a rapidly solidified Al-10 Sb alloy

    International Nuclear Information System (INIS)

    Wang Yan; Zhang Zhonghua; Geng Haoran; Wang Weimin; Bian Xiufang

    2006-01-01

    In the present work, the microstructure of a melt-spun Al-10 Sb alloy has been characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that rapid solidification has no influence on the phase constitution of the Al-10 Sb alloy. Moreover, the phase constitution does not change with increasing quenching rate (wheel speed). However, rapid solidification has a significant effect on the microstructure of the Al-10 Sb alloy. The microstructure of the melt-spun Al-10 Sb alloy dominantly comprises equiaxed primary AlSb dendrites and nanoscale α-Al/AlSb eutectic, different from that of the ingot-cast alloy consisting of coarse primary AlSb plates within the α-Al/AlSb eutectic matrix. Some epitaxial orientation relationships were found between AlSb particles and α-Al matrix in the melt-spun Al-10 Sb alloy as follows: α-Al [310] parallel AlSb [110] and α-Al (002) parallel AlSb (22-bar 0)

  16. 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

  17. The ALS Gun Electronics system

    International Nuclear Information System (INIS)

    Lo, C.C.

    1993-05-01

    The ALS Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

  19. Effect of the bismuth content on the interface reactions between copper substrate and Sn-Zn-Al-Bi lead-free solder

    Directory of Open Access Journals (Sweden)

    Soares, D.

    2005-12-01

    Full Text Available Because of environmental and health concerns, some alternative solder alloys, named lead-free ones, are being developed. Among them, the Sn-Zn-Al system has been studied and reveals promising properties. In this work the presence of bismuth, in the range of 0-8 wt%, was evaluated in what concerns to the chemical interactions between solder/substrate and the equilibrium phases present at the interface. The phases formed at the interface between the copper substrate and a molten lead-free solder were studied with different time of stage and alloy compositions. The effect of bismuth content on transformation temperatures of a Sn-9Zn-1Al base alloy was studied by Differential Scanning Calorimetry (DSC. For each alloy the solidification range was determined, which is an important characteristic regarding the application of these materials in the electronic industry. Identification of equilibrium phases and their chemical composition evaluation was performed by scanning electron microscopy (SEM/EDS. The interface thickness and chemical composition profiles were also evaluated.

    Debido a las preocupaciones ambientales y sanitarias, se están desarrollando aleaciones alternativas para soldadura sin plomo. Entre ellas se ha estudiado el sistema Sn-Zn-Al, que revela propiedades prometedoras. En este trabajo se evalúa la presencia de bismuto, en el rango de 0 a 8 % en peso, en relación con las interacciones químicas entre soldadura y substrato y con las fases de equilibrio presentes en la superficie de contacto. Se han estudiado las fases formadas en la superficie de contacto entre el substrato de cobre y una soldadura fundida sin plomo en función del tiempo de mantenimiento y de la composición de la aleación. Se ha evaluado el efecto del contenido en bismuto sobre las temperaturas de transformación de una aleación de base Sn-9Zn-1Al mediante Calorimetría de Barrido Diferencial (DSC. Se ha determinado el rango de solidificación para cada

  20. Çalışanların İş ve Ücret Tatmini Boyutlarıyla Demografik Özellikler Arasındaki İlişkiler: Bir Alan Çalışması(The Relationships Between Employees’ Job and Pay Satisfaction and Their Demographic Characteristics

    Directory of Open Access Journals (Sweden)

    Mehmet GÜVEN

    2005-01-01

    Full Text Available Human capital is considered to be one of the most important assets of the companies in a global business world. Managers equipped with modern management thoughts believe that employees will be happy and productive only if their needs and expectations are satisfied and they are motivated and happy in their work life. For this reason, it is important for the companies to have satisfied employees from their job. Therefore, companies should try to increase their employees’ job satisfaction level by implementing various managerial activities. In this study, the relationship between two aspects of job satisfaction (satisfaction with the work itself, satisfaction with pay and demographic characteristics was investigated. The data for this study was collected through survey conducted on a textile company operating in the city of Kahramanmaraş. The results indicate that there is statistically significant relationship between job satisfaction level and education level, and between wage satisfaction and two demographic characteristics, which are age and education level.

  1. PRÁCTICAS DE CONSUMO DE BEBIDAS ETÍLICAS EN UNA “CASA DE NEGOCIOS” PAMPEANA DE FINES DEL SIGLO XIX. ANÁLISIS DE PRECINTOS DE PLOMO Y DE FRAGMENTOS VÍTREOS (POSTA EL CALDÉN, DEPARTAMENTO DE REALICÓ, LA PAMPA / Alcohol consumption practices at a pampa´s ge

    Directory of Open Access Journals (Sweden)

    Virginia Pineau

    2014-11-01

    Full Text Available En el marco del proyecto Ubacyt F 095 que tiene como parte de sus objetivos estudiar y comprender el poblamiento del norte de la provincia de La Pampa posterior a las campañas militares de fines del siglo XIX, se presenta el análisis de los precintos de plomo y fragmentos vítreos provenientes del sitio Posta el Caldén (sección I, fracción A, lote 24. Dicho sitio se trata de una posta de caminos y casa de negocios ocupada hacia fines del siglo XIX. La misma pertenecía a una línea de postas entre las ciudades de Victorica (Provincia de La Pampa y General Villegas (Provincia de Buenos Aires. Se realizarán análisis morfológico – funcional, metalográfico mediante microscopia óptica (LM y electrónica de barrido (SEM y químico utilizando espectroscopia de rayos X dispersiva en energía (EDS de las piezas bajo estudio. El objetivo fue determinar tipos de bebidas alcohólicas consumidas y procedencia de las mismas. Se identificaron diversos tipos y marcas de bebidas de tenor etílico, se determinó que el material de confección de los precintos era de plomo recubierto con estaño típico de la técnica de confección denominada roll bonding. Esta información será de utilidad a la hora de estudiar las prácticas sociales de estos nuevos grupos de inmigrantes en combinación con las fuentes escritas y la historia oral.   Palabras Clave: Bebidas alcohólicas, Siglo XIX, La Pampa.     Abstract Within the framework of Ubacyt F 095 project that has as part of its aims to study the settlement of the northern province of La Pampa after the military campaigns of the late nineteenth century. We present the analysis of lead seals and fragments vitreous from the site Posta Caldén (Section I, Dept A, lot 24. This site is a crossroad post and a grocery store in the late nineteenth century. It belonged to a line of posts between the cities of Victorica (Province of La Pampa and General Villegas (Province of Buenos Aires. Morphological and

  2. 143 - 148_Makeri et al.

    African Journals Online (AJOL)

    USER

    2015-06-01

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

  3. Exposición ocupacional y ambiental al arsénico: actualización bibliográfica para investigación científica

    Directory of Open Access Journals (Sweden)

    Augusto V. Ramírez

    2013-07-01

    Full Text Available El arsénico (As es un metaloide presente en minerales complejos que contienen cobre, plomo y otros; en el trabajador causa arsenicismo ocupacional y la principal exposición ocurre en metalurgia del cobre. Sus compuestos trivalentes tienen tendencia acumulativa e ingresan por las vías respiratoria, digestiva o cutánea y se transforman en los ácidos dimetilarsínico y metilarsónico. En la mitocondria, con el azufre de los grupos mercapto forma enlaces covalentes y desacopla la fosforilación oxidativa, sugiriendo una acción inhibitoria no hidrolítica a ese nivel. Es cancerígeno para varios órganos. Se excreta por orina, heces y piel. Los peces y mariscos contienen arsénico orgánico. En sujetos no expuestos, dependiendo de la dieta, el As inorgánico en orina es < 5 ug/L. El índice de exposición biológica para trabajadores medido al final de la semana laboral es 35 µg/g creatinina y el valor límite umbral para ambientes de trabajo es 0,01mg/m³. La arsina es el compuesto arsenical más tóxico. El arsénico contenido en el agua de ciertas regiones produce la enfermedad ambiental llamada hidroarsenicismo crónico regional endémico.

  4. ILM AL LUGHAH AL IJTIMAI WA TALIM AL LUGHAH AL ARABIYYAH LI AL NATHIQINA BI GHAIRIHA

    Directory of Open Access Journals (Sweden)

    Ahmad Ubaedillah Fathuddin

    2017-03-01

    Full Text Available Language learning cannot work without integrating other fields of knowledge such as psychology, anthropology, sociolinguistics, etc. Sociolinguistics is a branch of linguistics which discusses about language due to social factors. It has an important role in language learning especially in making it easily understandable for the language learners by understanding the language use of the native speakers. The contribution of sociolinguistics in Arabic language learning for foreign language learners can be seen from the relationship between language and social environment. In this case, it does not only learn about the elements or internal systems of Arabic language such as phonology, syntax, and morphology, but also the social context such as speech community, social class, language use and culture. It means sociolinguistics gives information about the definition and use of Arabic language based on the social context.

  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. Kinematics of Disease Progression in Bulbar ALS

    Science.gov (United States)

    Yunusova, Yana; Green, Jordan R.; Lindstrom, Mary J.; Ball, Laura J.; Pattee, Gary L.; Zinman, Lorne

    2010-01-01

    The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech…

  7. Evaluation of Functional Disability in ALS

    Directory of Open Access Journals (Sweden)

    Akbar Soltan-Zadeh

    2002-06-01

    Full Text Available Objective: Amyotrophic Lateral Sclerosis (ALS is a progressive degenerative fatal disorder of motor neuron. In this research course of functional disability and possible underlying factors affecting disability were studied. Materials & Methods: First 59 patients with definite ALS were selected and for each patient ALSFRS (ALS Functional Rating Scale was determined at Initial and the end of a six month period. Results: During this period 9 patients expired. Bulbar onset localization showed a more rapid course than non-bulbar onset group. Conclusion: There was no significant relationship between the age group or gender with progression of disability. In expired group, mean survival in bulbar onset and older patients were significantly less than those with non-bulbar onset and younger ones. There was no significant relationship between survival and gender.

  8. Alles is al uitgevonden

    NARCIS (Netherlands)

    J.G.M. van Marrewijk (Charles)

    1996-01-01

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

  9. ALS (Amyotrophic Lateral Sclerosis)

    Science.gov (United States)

    ... here Home » Disorders » Patient & Caregiver Education » Fact Sheets Amyotrophic Lateral Sclerosis (ALS) Fact Sheet What is amyotrophic lateral sclerosis? Who ... Where can I get more information? What is amyotrophic lateral sclerosis? Amyotrophic lateral sclerosis (ALS) is a group of ...

  10. Lukman et al. (5)

    African Journals Online (AJOL)

    DELL

    1 Civil Engineering Department, Obafemi Awolowo University, Ile-Ife- Nigeria and Corresponding author. 2Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Samaru, Zaria- Nigeria s Department of Civil Engineering, University of Hafr Al-Batin, Hafr Al-Batin, Saudi Arabia.

  11. Taiwo et al (8)

    African Journals Online (AJOL)

    DELL

    gender equity (Waddington et al., 2009). These benefits act as barriers to transmission of diseases from the environment to the human body (Kosek et al., 2003). The disease burden that results from poor access to improved source of drinking water is significant; the WHO estimated that more than. 9% of the disease burden ...

  12. Adekola et al (7)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Orange Basin as part of oil exploration protocols. (van Der Spuy, 2003; Hirsch et al., 2009; Hirsch et al., 2010). ... in the determination of both oil and gas reservoirs and potential source rocks (Franca and Potter,. 1988). ...... opening. Geophysical Journal International. 168, 353-361. Franca, A.B., and Potter, P.E. 1988.

  13. Lukman et al. (5)

    African Journals Online (AJOL)

    DELL

    Keywords: Access to Safe Water Supply Technologies, Piped Water, Borehole, Millennium Development. Goals ... treated water to consumers (Ishaku et al., 2011). .... visited to ascertain access to safe water supply technologies. Lukman et al.: Effect of Selected Factors on Water Supply and Access to Safe Water in Nigeria ...

  14. Oloyede et al (19)

    African Journals Online (AJOL)

    Timade VENTURE

    field grasshopper) and Lirnicolaria oleira (small snails) feed on the leaflets of N. furcans.Herbivores feeding on some species of pteridophytes have been reported (Babayemi et al., 2006; Biplap and. Subir, 2007; Oloyede et al., 2008, 2010, 2012) as further evidence of nutritious value of some pteridophytes. The lethal dose ...

  15. Alimba et al (5)

    African Journals Online (AJOL)

    USER

    other countries. Numerous genotoxic and. c a r c i n o g e n i c c o m p o u n d s ; alkenylbenzenesestragole, methyleugenol, safrole, β-asarone, unsaturated pyrrolizidine, aromatic steroids, cytochalasin, concentricolide, are increasingly being reported in many of these medicinal botanicals(Qin et al., 2006; Rietjens et al.,.

  16. Interview als Text vs. Interview als Interaktion

    Directory of Open Access Journals (Sweden)

    Arnulf Deppermann

    2013-09-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  18. RETRACTED ARTICLE: Microstructures and morphologies of B2-Ordered NiAl(Co) and FeAl(Co)

    Science.gov (United States)

    Oh, Chang-Sup; Han, Chang-Suk

    2013-03-01

    Fine dispersion of disordered phases is obtained in a Ni-Al-Co and Fe-Al-Co ternary system. A transmission electron microscopy investigation has been performed in the present work on the precipitation of supersaturated B2-ordered (Ni,Co)Al and α-Fe in B2-ordered FeAl(Co) with different stoichiometries. Precipitation behavior and hardening were investigated by measuring the hardness variation. The hardness of (Ni,Co)Al and B2-FeAl(Co) increased appreciably by the fine precipitation of (Ni,Co)2Al, α-Fe, and overage softening occurred after prolonged aging. In case of B2-ordered (Ni,Co)Al, the (Ni,Co)2Al phase had a hexagonal structure and took a rod-like shape with the long axis of the rod parallel to the directions of the B2 matrix. By aging at temperatures below 873 K, a long period superlattice structure appeared in the hexagonal (Ni,Co)2Al phase. The orientation relationship between the (Ni,Co)2Al precipitates and the B2-(Ni,Co)Al matrix was (0001)p//(111)B2 and [bar 12bar 10]_p //[bar 110]_{B2}, where the suffix p and B2 denote the (Ni,Co)2Al precipitate and the B2-(Ni,Co)Al matrix, respectively. (Ni,Co)Al hardened appreciably by the fine precipitation of the (Ni,Co)2Al phase. On the other hand, in case of B2-FeAl(Co), the disordered α-Fe phase was present as a precipitate in a B2-FeAl(Co) matrix and had a cubic-cubic orientation with the matrix. At the early aging periods, prismatic dislocation loops formed in the B2-FeAl(Co) matrix. B2-FeAl(Co) matrix was typically hardened by the precipitation of α-Fe.

  19. August Reichensperger als Rechtspolitiker

    OpenAIRE

    Strauch, Dieter Prof. Dr.

    2006-01-01

    August Reichensperger, dessen Tätigkeit als Kölner Appellationsgerichtsrat, als Förderer der Fertigstellung des Kölner Domes und als Parlamentarier des Zentrums heute durch die Namensgebung für den Platz vor dem Kölner Oberlandesgericht geehrt wird, wurde 1808 in Koblenz geboren und wuchs bei seiner juristischen Ausbildung in das französisch/rheinische Recht hinein, das er zeitlebens gegen preußische Versuche, es durch altpreußisches Recht zu ersetzen, verteidigte. Er wurde Mitglied der ...

  20. Universitat popular al Cabanyal

    OpenAIRE

    Ribés Granell, Juan Miguel

    2012-01-01

    La intención es dotar al barrio de un gran espacio verde y de un edificio de interés para los vecinos que enriquezca al Cabanyal, ya que actualmente se encuentra en proceso de degradación. Se pretende desarrollar un proyecto que signifique una mejora en la predisposición del visitante, cubriendo sus necesidades. Al mismo tiempo, se busca crear un espacio arquitectónico que mejore la relación entre las actividades que incluye y su entorno. El proyecto está condicionado por cuatro aspectos fund...

  1. Cartas al editor

    Directory of Open Access Journals (Sweden)

    Facultad de Medicina Revista

    1995-10-01

    Full Text Available Con respecto al ensayo "Evaluación del aprendizaje en la educación superior" de la Dra. Análida Pinilla / Ciencia y conciencia en la medicina colombiana / Farmacovigilancia: Una necesidad urgente

  2. Platt et al. 1988

    African Journals Online (AJOL)

    denise

    dependent values of chlorophyll concentration (Sathyendranath et al. 1995). This sub- surface chlorophyll structure needs to be extrapolated spatially and temporally for the estimation of integrated pigment content and primary production (Sathyen-.

  3. Advanced Light Source (ALS)

    Data.gov (United States)

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

  4. Kulturmorphologie als Zivilisationskritik

    DEFF Research Database (Denmark)

    Peters, Rikke Alberg

    2010-01-01

    Der Untergang des Abendlandes wird oft als dasjenige Werk betrachtet, das am tiefsten die national gefärbte Gegenüberstellung von Kultur und Zivilisation in der Zwischenkriegszeit geprägt und propagiert hat. Wie auch bei anderen Autoren der Konservativen Revolution, vor allem bei Thomas Mann und...... Arthur Moeller van den Bruck, tritt der Begriff ‚Kultur’ bei Spengler als normativer Wertbegriff auf, der im Kontrast zu einer degenerierten und seelenlosen Zivilisation steht....

  5. Falaiye et al (19)

    African Journals Online (AJOL)

    (5.8%), goethite [Fe O .H O] (4.6%), halloysite [Al Si O (OH) ·8H O] (3.9%) and kaolinite [Al Si O (OH) ]. 2. 3. 2. 4. 4. 10. 8. 2. 4. 4. 10. 8 ..... Journ of Theor and App. Clim.,40(3), 161-169. Balogun, E.E. 1974. The Phenomenology of the. Atmosphere over West African. Proceedings of Ghana Scope's. Conference on Environment ...

  6. 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...

  7. RESPUESTA DE CAFETALES AL SOL Y BAJO SEMISOMBRA A NITRÓGENO Y SU RELACIÓN CON LA MATERIA ORGÁNICA DEL SUELO COFFEE CROPS RESPONSE TO NITROGEN ON DIRECT SUNLIGHT AND SEMI-SHADOW AND ITS RELATIONSHIP WITH THE SOIL’S ORGANIC MATTER

    Directory of Open Access Journals (Sweden)

    Siavosh Sadeghian Khalajabadi

    2011-06-01

    Full Text Available La materia orgánica del suelo (MO puede llegar a ser una fuente importante de nitrógeno (N para las plantas. Mediante el desarrollo de esta investigación se evaluó la respuesta de cafetales a plena exposición solar y bajo semisombra al suministro de N y su relación con la MO. Para ello se seleccionaron 20 plantaciones al sol y 12 con semisombra en 25 municipios de Colombia, contrastantes en su contenido de MO (desde 4 hasta 28%. Se evaluaron dos tratamientos, uno con N, P, K y Mg y el otro sin N, el cual se aplicó en dosis de 240 kg ha-1 año-1 como urea. En los cafetales al sol el efecto de la carencia de N sobre la producción se manifestó a partir del segundo año y se aumentó gradualmente, hasta alcanzar reducciones cercanas al 50% en el cuarto año; bajo semisombra se registró un comportamiento similar pero de menor magnitud. En ambos sistemas de producción, el comportamiento del rendimiento relativo en función del contenido de materia orgánica, se ajustó a un modelo cuadrático, con punto de inflexión en el 18% de la variable independiente. El suministro de N disminuyó el pH del suelo y aumentó las pérdidas de K+ en los dos sistemas; en los cafetales al sol se incrementaron los contenidos foliares de N, Mg y Mn por el efecto del N, mientras que las concentraciones de P, K, Cu y B disminuyeron. En las plantaciones desarrolladas bajo semisombra la fertilización nitrogenada sólo aumentó el contenido foliar del Mn y redujo el B.Soil’s organic matter (OM can be an important source of nitrogen (N for plants. Through the development of this investigation the response of coffee in full sunlight and under light shade to the supply of N and its relationship to OM was evaluated. For this, 20 plantations exposed to direct sunlight and 12 under semi-shade were selected in 25 municipalities in Colombia, with different content of OM (from 4 to 28%. Two treatments were evaluated, one with N, P, K and Mg and the other without N

  8. 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.

  9. Photoelectron spectroscopy of the aluminum hydride anions: AlH2(-), AlH3(-), Al2H6(-), Al3H9(-), and Al4H12(-).

    Science.gov (United States)

    Zhang, Xinxing; Wang, Haopeng; Collins, Evan; Lim, Alane; Ganteför, Gerd; Kiran, Boggavarapu; Schnöckel, Hansgeorg; Eichhorn, Bryan; Bowen, Kit

    2013-03-28

    We report measurements of the negative ion photoelectron spectra of the simple aluminum hydride anions: AlH2(-), AlH3(-), Al2H6(-), Al3H9(-), and Al4H12(-). From these spectra, we measured the vertical detachment energies of the anions, and we estimated the electron affinities of their neutral counterparts. Our results for AlH2(-), AlH3(-), and Al2H6(-) were also compared with previous predictions by theory.

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

    International Nuclear Information System (INIS)

    Hecht, U; Witusiewicz, V; Drevermann, A

    2012-01-01

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

  11. Selbstkritik als wissenschaftliches Projekt?

    Directory of Open Access Journals (Sweden)

    Barbara Scholand

    2007-11-01

    Full Text Available Wallner kritisiert die aktuelle feministische Darstellung der rund 30jährigen Geschichte der Mädchenarbeit als „Legendenbildung“ (S. 9: Sie verkürze und verschweige im Interesse einer Selbst-Heroisierung und sei daher ideologisch. Als eine derjenigen, die seit zwanzig Jahren feministische Mädchenarbeit und -politik betreibt, arbeitet die Autorin damit auch ihre eigenen (Nicht-Bezugnahmen kritisch auf. Ihr grundlegendes Interesse ist es, eine aus ihrer Sicht erforderliche Neupositionierung der Mädchenarbeit in der Jugendhilfe im Zeitalter von Gender Mainstreaming zu befördern.

  12. ALS superbend magnet system

    International Nuclear Information System (INIS)

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-01-01

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R and D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing

  13. Dichtung als Erfahrungsmetaphysik

    DEFF Research Database (Denmark)

    Magnusson, Gisli

    Rilkeforskning. Fordi Rilke ikke – uden at gøre vold mod hans værk – kan fortolkes ud fra et traditionelt religiøst verdensbillede, har man fortolket ham som en antimetafysisk mo­dernist. Afhandlingen Dichtung als Erfahrungsmetaphysik. Esoterische und okkultistische Modernität bei R. M. Rilke argumenterer for...

  14. Okusanya et al (5)

    African Journals Online (AJOL)

    DELL

    subcontinent and it is distributed in various tropical and sub-tropical regions including Asia,. Central and South America, Australia, West. Indies, Africa, (Orwa et al., 2009) and in Florida and Texas in the United States of America. (Brown, 2001). It has recently been spotted in. Brick Township, New Jersey, U. S. A. and in Israel.

  15. Adjei et al.

    African Journals Online (AJOL)

    PUBLICATIONS1

    Glass products appear in varied types based on the material composition. It is an amorphous. (non-crystalline) solid material which is often transparent with widespread practical, techno- logical, and decorative applications. Examples are windowpanes, beverage containers, table wares, and optoelectronics (Babcock et al,.

  16. Adeleye et al (20)

    African Journals Online (AJOL)

    DELL

    2018-03-03

    Mar 3, 2018 ... terrestrial and aquatic settings and the proxies are mostly drawn from sedimentary deposits such as lakes, marine deposits, peatlands and other wetlands such as marshes and swamps (Jeglum and Rydin, 2006; Smol et al., 2001). It is commonly stated that the present condition of the biosphere is the result ...

  17. Onojeghuo et al (16)

    African Journals Online (AJOL)

    USER

    one under community-based forest management and the other a protected area were compared to evaluate the efficiency of community forest management. The results showed ... Onojeghuo et al.: Community Participation in Forest Management Across Protected Areas .... using the unsupervised Iterative Self Organising.

  18. Oke et al. (12)

    African Journals Online (AJOL)

    the enforcement of good quality control measures. Keywords: Hand Sanitizer, Hand Hygiene, Bactericidal, Bacteriostatic, MIC, MBC. ABSTRACT. INTRODUCTION. Hospital and community-acquired infections constitute a serious public health problem all over the world (Hassan et al., 2012). Hospital acquired. (nosocomial) ...

  19. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  20. Ojo et al. (15)

    African Journals Online (AJOL)

    DELL

    This work presents analyses of data on cancers diagnosed and recorded at the Ife-Ijesa Cancer Registry located ... physical inactivity, as well as changing dietary and lifestyle patterns. [Sylla and Wild, 2011, Jedy-Agba et al., 2012]. It is generally accepted that a large number of cancers .... for Appendix, Bowel and Duodenal.

  1. Akpen et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    reduction of pollution in the stream. Sharma et al. (2003) monitored the water quality of Hathli. Akpen et ... dium roughness and the degree of sinusoidality is low to moderate with some few sharp bends. The temperature ... U, is the velocity in m/sec and H, is the depth in meters. The dispersion coefficient (Ex) was calculated ...

  2. Ipeaiyeda et al (15)

    African Journals Online (AJOL)

    DELL

    arousing public interest. Previous studies published so far on air pollution in Nigeria are on heavy metals in atmosphere using tree bark as indicator and airborne cement dust (Odukoya et al., 2000; Onianwa, 2001; Gbadebo and Bankole,. 2007). Estimation of air pollution arising from vehicular exhaust emission on Nigeria ...

  3. Adjaotor et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    A mathematical model was developed using multiple regression analysis to predict MRR during hard turning of AISI 304L ... regression line fits well for both results data at 95% confidence interval. INTRODUCTION. In order to respond ... replacement and regrinding times, ordering time etc. Tonshoff et al. (1995) stated that ...

  4. Joda et al (16)

    African Journals Online (AJOL)

    DELL

    treating gonorrhea, gonococcal urethritis and the vaginal/urethral discharge syndrome in developing countries like Nigeria (Abebe et al.,. 2001; WHO, 2007). In addition to being effective against Neiseria gonorrhoea, ciprofloxacin is indicated for bacterial infections like urinary tract infections (UTIs), acute uncomplicated ...

  5. Nucleosynthesis of 26Al

    International Nuclear Information System (INIS)

    Casse, M.

    1986-07-01

    A burst of interest has followed the discovery in the galactic plane of the 1.8 MeV gamma line attached to the decay of 26 Al. We discuss the relative merits of supernovae, novae, massive and supermassive mass-losing stars as potential sources of this expressive isotope

  6. Adeyemi et al (10)

    African Journals Online (AJOL)

    Acevedo-Rodríguez et al.(2011). The vegetative and reproductive morphology of. Sapindaceae shows similarities and differences among the various genera constituting the family. Pair-wise analysis of qualitative data generated a dendogram. A common feature in the dendogram is the clear separation of the family into two ...

  7. Ekun et al (6)

    African Journals Online (AJOL)

    DELL

    It must be noted that a significantly low total testosterone value as was observed among the hypertensive group may be an indicator to suggesting a subclinical hypogonadism. Furthermore, it was observed that the mean LH value in test group though marginally higher than. Ekun et al.: Levels of Reproductive Hormones ...

  8. Odukoya et al (25)

    African Journals Online (AJOL)

    USER

    Human exposure to toxic metals has increased dramatically in the last 50 years as a result of an exponential increase in the use of heavy metals in industrial processes and products (Sekabira et al.,. 2010). Solid and liquid wastes from these industries eventually get discharged into dumps or rivers from where they enter the ...

  9. Taiwo et al (15)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Extracted lipids were then analyzed by gas chromatography to determine the composition and relative abundance of the fatty acids present. .... allow for phase separation. The bottom chloroform layer was then collected after ..... in membranes than DHA (Subhadra et al., 2006). This could be the reason for the lower levels of.

  10. aboagye et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    14 Aboagye et al. wide variety of birds, including chickens, by piercing the quills of feathers and gnawing the epidermis. In doing so, they can spread disease and lower .... evolution. Oikos, 97: 223-228. Nordenfors, H. and Chirico, J. (2001). Evalua- tion of a sampling trap for Dermanyssus gal- linae (Acari: Dermanyssidae).

  11. Iraq and Al Qaeda

    National Research Council Canada - National Science Library

    Katzman, Kenneth

    2008-01-01

    .... The Administration assertions were derived from U.S. intelligence showing a pattern of contacts with Al Qaeda when its key founder, Osama bin Laden, was based in Sudan in the early to mid-1990s and continuing after he relocated to Afghanistan in 1996...

  12. Iraq and Al Qaeda

    National Research Council Canada - National Science Library

    Katzman, Kenneth

    2007-01-01

    .... The Administration's assertions were derived from U.S. intelligence showing a pattern of contacts with Al Qaeda when its founder, Osama bin Laden, was based in Sudan in the early to mid-1990s and continuing after he relocated to Afghanistan in 1996...

  13. Ismail et al (6)

    African Journals Online (AJOL)

    USER

    Analysis and design of pipes in water distribution networks generally create a relatively complex problem, particularly when the network consists of large number of pipes as frequently occurs in water distribution systems of large metropolitan areas and cities. (Saminu et al., 2013). There are various types of loops in pipeline ...

  14. Adeoti et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    Hence, for groundwater exploration, integration of techniques is most essential for success to be achieved economically (Rosli et al., 2012). The application of geophysics for the successful exploration of groundwater in sedimentary ter- rain requires a proper understanding of its hy- dro-geological characteristics. Evidence ...

  15. Ajibola et al (7)

    African Journals Online (AJOL)

    USER

    ponds and streams (Mohneke et al., 2010). The larval stage of the African tiger frog. (Hoplobatrachus occipitalis) is carnivorous and feeds on small aquatic animals like tadpoles and mosquito larvae, making them an important part of the food chain. A drop in population of H. occipitalis as a predator, due to overexploitation of.

  16. 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.

  17. Taiwo et al (10)

    African Journals Online (AJOL)

    DELL

    duration of marriage, birth interval, birth order and breast feeding practice. Uddin et al. (2009) in their study, investigated child mortality in. Bangladesh also using the logistic regression. Results of analysis showed that father's education, occupation of father, occupation of mother, standard of living index, breastfeeding status ...

  18. Olonisakin et al (15)

    African Journals Online (AJOL)

    DELL

    of a small probe were considered death (Su, 1976). Filter paper test. Bioassay on the toxicity of T. orientalis and E. camaldulensis essential oils against adult C. maculates was similar to the method described in Ukeh et al.,. 2012) in Pyrex glass Petri dishes (10 cm diameter). Different doses of each essential oil (0.01, 0.02,.

  19. Agwu et al (6)

    African Journals Online (AJOL)

    DELL

    Enterobacteriaceae, the bacteria Escherichia coli is regarded as non-halophilic, and cannot tolerate high salt concentrations (Abdulkarim et al., 2009). Nevertheless, some strains of E. coli are halo- tolerant and survive in high salt concentrations. The ability to demonstrate such high osmotic pressure is possibly due to the ...

  20. Alabi et al (19)

    African Journals Online (AJOL)

    is attractive as a selective solar absorber since it has high solar absorbency and a low thermal emittance. (Johan et al.,2011). The p-type semiconductor of copper oxide (CuO) is an important functional material used for gas sensors, magnetic storage media, solar energy transformation, electronics, semiconductors, varistors ...

  1. Omeike et al. (13)

    African Journals Online (AJOL)

    was used for sorption of Al ions at low concentrations of 10-50 mg/L. Effect of contact time and pH on biosorption of aluminium ions from solution was also evaluated. The result showed that highest aluminium sorption was obtained at pH 6 after 24 hours. Langmuir and Freundlich isotherm constants described a feasible.

  2. Samuel et al (13)

    African Journals Online (AJOL)

    DELL

    detrimental to the health of the users especially those with wounds on their skin. Keywords: Microbial contaminant, shea butter, local ... natural plant extract is almost magical in its healing effects on burns, skin rashes, ulcerated skin, ... aging and troubled skin to rejuvenate (Esiegbuya et al.,2014). Recently, there have been ...

  3. Esuuman et al (17)

    African Journals Online (AJOL)

    big timmy

    ether (Sathe et al., 2002). Various extraction conditions such as pH, solvent types (NaOH, NaCl or Ethanol), solvent concentration, extraction time, solvent/flour ratio, may affect the final properties of the extracted protein. When many factors and interactions affect desired responses in a certain process design, Response.

  4. Quagraine et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    ties, as discussed by Moore et al (2003) include education, retail, employment and other social services. These opportunities serve as both ru- ral or suburban push and urban pull factors for migration into major cities in Ghana (Ghana. Statistical Service, (GSS) 2005). Thus, about. 75% of migrants into the major cities in ...

  5. Hamid et al (24)

    African Journals Online (AJOL)

    USER

    acne, and eye problems (Diaz-Bolio, 1975). Cnidoscolus aconitifolius roots and leaves have been taken as a laxative, diuretic, circulation stimulant, to increase digestion, stimulant for lactation, and to harden the fingernails (Rowe, 1994; Kuti, and. Torres, 1996). Oyagbemi et al., (2011) reported the proximate analysis and ...

  6. Factores asociados al bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Georgina J Peraza Roque

    2001-10-01

    Full Text Available El bajo peso al nacer (BPN ha constituido un enigma en la ciencia a través de los tiempos. Múltiples son las investigaciones realizadas acerca de las causas que lo producen y las consecuencias que provoca. Su importancia no solo radica en lo que significa en la morbilidad y la mortalidad infantil, sino que estos niños tienen habitualmente múltiples problemas posteriores. El Programa para la Reducción del BPN señala que los niños nacidos con un peso inferior a los 2 500 g presentan riesgo de mortalidad 14 veces mayor durante el primer año de vida, en comparación con los niños que nacen con un peso normal a término. Dentro de los factores de riesgo del BPN se han encontrado con mayor frecuencia en estudios realizados por diferentes autores, los siguientes: el embarazo en la adolescencia, la desnutrición en la madre, el hábito de fumar, la hipertensión arterial durante el embarazo, la sepsis cervicovaginal, la anemia y los embarazos gemelares, entre otros. Es innegable la influencia que el BPN tiene sobre las futuras generaciones, por lo que debe constituir la diana de los esfuerzos que el médico y la enfermera deben desarrollar en su prevención, sobre todo en la comunidadLow birth weight has been an enigma for Science through times. A lot of research works have been carried out about its causes and consequences. The importance of LBW not only lies in its meaning for infant mortality and morbidity but also in the many problems that low birth weight children regularly face in the future. The program for the reduction of LBW points out that newborns weighing under 2500g have during his/her first year of life a mortality risk 14 times higher than newborns with a normal weight at term. Among the low birth weight risk factors, a number of studies by various authors have frequently found the following; pregnancy at adolescence; undernourishment in mothers, smoking, blood hypertension during pregnancy, cervix-vaginal sepsis; anemia, twin

  7. Evaluation of casting textures in Al/Al{sub 3}Ti platelet functionally graded material fabricated by a centrifugal solid-particle method

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Y.; Eryu, H.; Yamamoto, T. [Dept. of Functional Machinery and Mechanics, Shinshu Univ., Ueda (Japan); Andiarwanto, S.; Miura, H. [Dept. of Mechanical Engineering and Intelligent Systems, The Univ. of Electro-Communications, Tokyo (Japan)

    2002-07-01

    In this study, crystal orientation of the Al matrix in Al/Al{sub 3}Ti FGMs fabricated by the centrifugal solid-particle method was investigated by using orientation image microscopy (OIM). It was found that strong orientation of the Al{sub 3}Ti platelets was developed in the FGM fabricated under large G number, which is the ratio of the centrifugal force to the gravity. Contrarily to the expectation, strong texture of the Al matrix was not developed in the FGM even by solidification under strong centrifugal force, Moreover, there exists no specific relationship of crystallographical orientation between Al matrix and Al{sub 3}Ti platelets. Therefore, it would be concluded that nucleation and growth of Al matrix grains keeping specific orientation relationship with the pre-existing solid platelets seem to be difficult under dynamic casting with centrifugal force. (orig.)

  8. ALS Project Management Manual

    Energy Technology Data Exchange (ETDEWEB)

    Krupnick, Jim; Harkins, Joe

    2000-05-01

    This manual has been prepared to help establish a consistent baseline of management practices across all ALS projects. It describes the initial process of planning a project, with a specific focus on the production of a formal project plan. We feel that the primary weakness in ALS project management efforts to date stems from a failure to appreciate the importance of ''up-front'' project planning. In this document, we present a guide (with examples) to preparing the documents necessary to properly plan, monitor, and control a project's activities. While following the manual will certainly not guarantee good project management, failure to address the issues we raise will dramatically reduce the chance of success. Here we define success as meeting the technical goals on schedule and within the prescribed budget.

  9. Pemikiran Filsafat Al-kindi

    OpenAIRE

    Madani, Abu Bakar

    2015-01-01

    Al-Kindi is the first Muslim philosopher to construct Islamic philosophical thoughts in a systematic and clear way. Philosophical thoughts of Al-Kindi are reflection of doctrines that he received from classic Greece sources and the legacy of Neo-Platonic thoughts combined with Islamic faith. Al-Kindi opens the room of dialogue to combine philosophical doctrines and religion. Knowledge about God, according to Al-Kindi, is early philosophy or the first philosophy; philosophy that states al-Haqq...

  10. Derecho al desarrollo y globalidad

    OpenAIRE

    Álvarez Vita, Juan

    2014-01-01

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

  11. Religion als soziale Deutungspraxis

    Directory of Open Access Journals (Sweden)

    Ulrike Lingen-Ali

    2016-12-01

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

  12. DEUTSCHLAND ALS EINWANDERUNGSLAND

    OpenAIRE

    IVANDA, Katica

    2010-01-01

    Die vorliegende Arbeit versucht einen kurzen sozialhistorischen Überblick über das Migrationsgeschehen in Deutschland zu geben. Aus dem Auswanderungsland des 19. Jahrhunderts wurde ein Einwanderungsland neuen Typs. Die Anwerbephase der 60er-Jahre erweist sich retrospektiv als zeitliches Bindeglied zum „Einwanderungsland wider Willen“. Obgleich alle Beteiligten auf deutscher wie ausländischer Seite noch lange am Gastarbeitermythos der baldigen Rückkehr in die jeweiligen...

  13. Ausbildung als zentrale Aufgabe

    Science.gov (United States)

    Krämer, Walter; Schmerbach, Sibylle

    Anders als Lesen und Schreiben zählen Grundkenntnisse in Statistik heute noch nicht zu den Voraussetzungen einer sinnvollen Teilhabe am Sozialgeschehen. Und auch in der akademischen Statistik-Ausbildung gibt es noch einiges zu tun. Das vorliegende Kapitel zeichnet die Geschichte dieser akademischen Ausbildung an deutschen Universitäten nach dem zweiten Weltkrieg nach, stellt aktuelle Defizite vor und weist auf mögliche Verbesserungen hin.

  14. Valoración del riesgo en salud en un grupo de población de Cali, Colombia, por exposición a plomo, cadmio, mercurio, ácido 2,4-diclorofenoxiacético y diuron, asociada al consumo de agua potable y alimentos

    Directory of Open Access Journals (Sweden)

    Ghisliane Echeverry

    2015-08-01

    Conclusiones. Se cree que los hallazgos sobre contaminantes en estudios anteriores, pueden deberse a eventos puntuales de contaminación y se recomienda vigilar la bocatoma de agua y emitir alertas tempranas. El reporte sobre la presencia de cadmio en las muestras de pescado, sugiere que el control de la calidad de los alimentos por parte de las entidades reguladoras debe mejorar.

  15. Interdimensional Relationships.

    Science.gov (United States)

    Roberti, Joseph V.

    1988-01-01

    Notes that the derivative of the area of a circle yields the circumference and the derivative of the volume of a sphere yields the surface area. Explores where these or other such relationships are generalizable. (PK)

  16. Abusive Relationships

    Science.gov (United States)

    ... a big part of moving from childhood into adolescence and adulthood. Unfortunately, some people may find themselves in a relationship that involves abuse or violence. It can be especially hard for guys to ...

  17. Proximity effect Nb/Al,AlOxide, Al/Nb Josephson tunnel junctions

    NARCIS (Netherlands)

    Houwman, Evert Pieter; Gijsbertsen, J.G.; Gijsbertsen, Hans; Flokstra, Jakob; Rogalla, Horst; Le grand, J.B.; de Korte, P.A.J.; Golubov, Alexandre Avraamovitch

    1993-01-01

    Regions with reduced energy gap induced by the proximity effect give rise to quasi-particle loss in Josephson-junction X-ray detectors, but may also be used advantageously for quasi-particle collection. The influence of the thickness of the Al proximity layers in Nb/Al1 , AlOx, Al2/Nb Josephson

  18. 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.

  19. Ojo et al (2)

    African Journals Online (AJOL)

    DELL

    applied to discriminate rock samples into different rock types. In this study, the authigenic clay morphology (grain coating and pore filling) appear to have an excellent relationship with pore network geometry hence ... ragged plates while authigenic illite (formed through ... a few carbonate minerals such as siderite. Log data.

  20. Bam et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    was analyzed using Statistical Package for the Social Sciences (SPSS). The common stressors identified include “when ... area and used coping strategies that were mainly relationship-based. Greater collaboration be- tween educational ..... strategies to decrease nursing student anxiety in the clinical learning environment.

  1. Temitope et al (1)

    African Journals Online (AJOL)

    DELL

    against specific bacterial strains and moderate activities against other bacterial strains. The compounds did not show any sensitivity against the tested fungal strains. The quantitative structure-antibacterial activity relationship was studied using some quantum chemical parameters with the aid of Spartan 10 (V1.0.1) and.

  2. 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

  3. Englisch als Weltsprache

    OpenAIRE

    Locher, Miriam A.

    2011-01-01

    In den Medien wird Englisch oft als die Weltsprache schlechthin dargestellt. So titelte zum Beispiel Newsweek am 7. März 2005: «Who owns English? Non-native speakers are transforming the Global Language», und im Internet gibt es eine beachtliche Anzahl kommerzieller Unternehmen, die «Global English» anbieten. Was aber ist «Global English» und wie kam es überhaupt zu einer derart weiten Verbreitung und der überaus großen Bedeutung des Englischen in der heutigen Zeit? Der vorliegende Aufsatz wi...

  4. Del Pasadismo al Futurismo

    OpenAIRE

    Agudo-Martínez, M. J.

    2003-01-01

    Uno de los habituales prejuicios a la hora de abordar el análisis del movimiento futurista, al igual que sucede con el constructivismo, es la consideración del contexto político en el que se desarrollaron ambas vanguardias. Sin embargo, y dejando a un lado un enfoque del arte con finalidad política de signo diverso, habría que insistir en el hecho de que posiblemente sean tanto el futurismo italiano como el constructivismo ruso, los movimientos que con mayor entusiasmo se manifestaron, en un ...

  5. Programa Padres al Colegio

    OpenAIRE

    Viñeglas Fernández, Sandra

    2014-01-01

    El presente trabajo, es un proyecto orientado a la promoción de la salud, en referencia al virus del papiloma humano (VPH), ya que este virus es el causante de una de las infecciones de transmisión sexual más frecuentes en el mundo, el objetivo de este trabajo, es diseñar una serie de intervenciones que contribuyan a sensibilizar e informar a la ciudadanía, para lograr mejorar la prevención del virus del papiloma humano y el cáncer de cérvix. Como ya es sabido, cualquier intervención sobre...

  6. ATXN2 trinucleotide repeat length correlates with risk of ALS.

    Science.gov (United States)

    Sproviero, William; Shatunov, Aleksey; Stahl, Daniel; Shoai, Maryam; van Rheenen, Wouter; Jones, Ashley R; Al-Sarraj, Safa; Andersen, Peter M; Bonini, Nancy M; Conforti, Francesca L; Van Damme, Philip; Daoud, Hussein; Del Mar Amador, Maria; Fogh, Isabella; Forzan, Monica; Gaastra, Ben; Gellera, Cinzia; Gitler, Aaron D; Hardy, John; Fratta, Pietro; La Bella, Vincenzo; Le Ber, Isabelle; Van Langenhove, Tim; Lattante, Serena; Lee, Yi-Chung; Malaspina, Andrea; Meininger, Vincent; Millecamps, Stéphanie; Orrell, Richard; Rademakers, Rosa; Robberecht, Wim; Rouleau, Guy; Ross, Owen A; Salachas, Francois; Sidle, Katie; Smith, Bradley N; Soong, Bing-Wen; Sorarù, Gianni; Stevanin, Giovanni; Kabashi, Edor; Troakes, Claire; van Broeckhoven, Christine; Veldink, Jan H; van den Berg, Leonard H; Shaw, Christopher E; Powell, John F; Al-Chalabi, Ammar

    2017-03-01

    We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we systematically searched PubMed for case-control studies published after 1 August 2010 that investigated the association between ATXN2 intermediate repeats and ALS. We conducted a meta-analysis of the new and existing studies for the relative risks of ATXN2 intermediate repeat alleles of between 24 and 34 CAG trinucleotide repeats and ALS. There was an overall increased risk of ALS for those carrying intermediate sized trinucleotide repeat alleles (odds ratio 3.06 [95% confidence interval 2.37-3.94]; p = 6 × 10 -18 ), with an exponential relationship between repeat length and ALS risk for alleles of 29-32 repeats (R 2  = 0.91, p = 0.0002). No relationship was seen for repeat length and age of onset or survival. In contrast to trinucleotide repeat diseases, intermediate ATXN2 trinucleotide repeat expansion in ALS does not predict age of onset but does predict disease risk. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  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. 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

  10. AL-USRCRN Station Information

    Data.gov (United States)

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

  11. 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

  12. Njan et al (9).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    induced pain through analgesiometer, tail immersion test, hot-plate, and acetic acid-induced analgesic test methods. HME, significantly and dose-dependently produced analgesic effects ... intensive work has been done in this area of ethnopharmacology (Iwalewa et al., 2003,. Omisore et al., 2004, Fadeyi et al., 2004, ...

  13. The relationship between low birth weight and exposure to inhalable particulate matter Relación entre el bajo peso al nacer y la exposición a partículas inhalables Relação entre baixo peso ao nascer e exposição ao material particulado inalável

    Directory of Open Access Journals (Sweden)

    Alfésio Luiz Ferreira Braga

    2013-06-01

    Full Text Available Atmospheric pollution is a global public health problem. The adverse effects of air pollution are strongly associated with respiratory and cardiovascular diseases and, to a lesser extent, with adverse pregnancy outcomes. This study analyzes the relationship between exposure to PM10 and low birth weight in the city of Santo André, São Paulo State, Brazil. We included babies born to mothers resident in Santo André between 2000 and 2006. Data on daily PM10 levels was obtained from the São Paulo State Environmental Agency. We performed descriptive analysis and logistic regressions. The prevalence rate of low birth weight was 5.9%. There was a dose-response relationship between PM10 concentrations and low birth weight. Exposure to the highest quartile of PM10 (37,50µg/m³ in the third trimester of pregnancy increased the risk of low birth weight by 26% (OR: 1.26; 95%CI: 1.14-1.40 when compared to the first quartile. The same effect was observed in the remaining trimesters. This effect was observed for ambient particle concentrations that met the current air quality standards.La contaminación del aire en todo el mundo es un problema de salud pública. Los efectos adversos relacionados con los contaminantes del aire están fuertemente asociados con enfermedades respiratorias y cardiovasculares, pero en menor medida con los resultados adversos del embarazo. En este estudió se evaluó la relación entre PM10 y bajo peso al nacer en el municipio de Santo André, São Paulo, Brasil. Se incluyeron en el estudio los recién nacidos de madres residentes en Santo André (2000-2006. La Agencia ambiental del Estado de São Paulo informó de los índices diarios de PM10. Además, se realizó un análisis descriptivo y por regresión logística. La prevalencia de bajo peso al nacer fue de un 5,9%. Hubo una relación dosis-respuesta entre las concentraciones de PM10 y bajo peso al nacer. Las concentraciones de PM10 en el cuartil más alto (37,50µg/m³ en el

  14. Salvar al planeta

    Directory of Open Access Journals (Sweden)

    Thomas Sancton

    2015-01-01

    Full Text Available El desastre de Exxon Valdez en Canadá (1989en que derramaron 262 mil barriles de petróleo en las aguas de Alaska cambió la conciencia de los norteamericanos para bien. Comienzan a preocuparse, les gusta ser ecologistas. Se espera que no sea moda o novelería y que asuman el liderazgo para salvar al planeta, pues la deforestación, el incremento de la población, la quema de combustibles fósiles, el calentamiento global, el agujero de ozono sobre la Antártida dejan intuir que la Tierra está en grave peligro. Se recomienda entonces optar por un desarrollo sustentable.

  15. 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.

  16. Carta al Editor

    Directory of Open Access Journals (Sweden)

    Darío Maldonado Romero

    1991-03-01

    Full Text Available

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

    Señores doctores:

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

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

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

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

    A menos de un año de

  17. Atributos do Serviço de Transporte no Relacionamento Indústria-VarejoAttributes of Transport Service in Retail-Industry RelationshipAtributos del Servicio de Transporte en la Relación Industria-Ventas al por Menor

    Directory of Open Access Journals (Sweden)

    MARTINS, Ricardo Silveira

    2011-06-01

    the supply chains. In the universe of 400 manufacturing companies located in the state of Minas Gerais, 101 were selected as they had a retail account for more than 60% of their sales, which was analyzed as to the desired constructs and attributed evaluation. In general, industrial shippers seem to minimize the importance of logistics in the retail service, giving the transport merely operational functions and not strategic ones. They fail to aggregate the value of logistics to their products and services. The results forwarded to specific management issues relevant such as the relationship between orders fulfillment and problems of internal processes, structure of distribution channels, logistics networks and decisions about to internalizing/outsourcing logistics services.RESUMENEn el segmento de la distribución, las actividades logísticas se perciben más fácilmente como generadoras de valor. Entre ellas, el transporte tiene gran significado. Así, este estudio tuvo por objetivo analizar la gestión del transporte en las empresas industriales que trabajan con ventas al por menor. La motivación de los estudios se debe a que, en la literatura hay evidencias de que, la forma de gestionar el transporte en términos de atributos del servicio es diferente según el cliente; como también en lo referente al formato de la demanda de servicios de transporte y sus especificidades para atender segmentos de la cadena de suministro. Entre 400 empresas industriales instaladas en el estado de Minas Gerais, se seleccionaron 101, cuyas ventas al por menor correspondían a más del 60% de las ventas, se realizaron análisis de los constructos deseados y evaluación de atributo. En general, los embarcadores industriales parecen minimizar la importancia de la logística en los servicios al por menor y atribuyen al transporte funciones meramente operacionales, o sea, no estratégicas. Por lo tanto, dejan de agregar el valor de la logística a sus productos y servicios. Los

  18. Cd-Sb-Al system

    International Nuclear Information System (INIS)

    Belotskij, D.P.; Dundich, M.S.; Kotsyumakha, M.P.; Makhova, M.K.; Lesina, N.V.; Noval'kovskij, N.P.

    1985-01-01

    The methods of differential-thermal, microstructural analyses and measuring microhardness are used to investigate the phase diagrams of polythermal sections CdSb-AlSb, CdSb-Al, Cd-AlSb, Cdsub(0.5)Alsub(0.5)-Sb, CdSb-Alsub(0.2)Cdsub(0.8) of the ternary system Cd-Sb-Al. The liquidus projection of the Cd-Sb-Al system is plotted; it has been found that the surface of aluminium antimonide formation occupies a large part of the phase diagram in the field of which the lamination region is located

  19. Cu doped AlSb polycrystalline thin films

    International Nuclear Information System (INIS)

    Wu Lili; Jin Shuo; Zeng Guanggen; Zhang Jingquan; Li Wei; Feng Lianghuan; Li Bing; Wang Wenwu

    2013-01-01

    Cu-doped AlSb polycrystalline films were grown on quartz glass by magnetron co-sputtering. The structural, morphological and electrical properties of the films were studied. The incorporation of copper atoms can result in the increase of lattice constants, and annealing is helpful to eliminate this deformation. Cu-doped AlSb films exhibit weak n-type conductivity. The results show that the doping effect has a close relationship with the annealing process, meaning that the position of Cu atom in AlSb polycrystalline films might influence the doping effect. (semiconductor materials)

  20. Idaaratu al Wahdah al Namthiyah li at Tathwiri al Tarbiyah al Islamiyah

    Directory of Open Access Journals (Sweden)

    Ahmad Danusiri

    2016-04-01

    Full Text Available Islam, through the Quran, proclaims that its mission includes the teachings to the whole universe, Everything in the universe is maintained by Islam, and none of the symptoms are ignored. The revelations also include the traditions of the Prophet that are authentic (shahih and good (hasan in quality. Both the Quran and maqbulah hadiths are accepted by Muslims on the basis of faith. When some experts of UIN Walisongo from various disciplines try to understand the sacred words of these two resources, their understanding continues, reaching the paradigm of the unity of science which essentially unites the normative, social, and natural sciences. The effect of this paradigm has brought up an issue for the author. Is there any hadiths or Prophetic traditions that can be used as a grand theory in the management disciplines of Islamic education.To address this issue, the authors conducted a literature research with the title Development of Islamic Education Management Module. Sources of data were focused on nine books of Hadiths : Sahih al-Bukhari, Sahih al-Muslim, Sunan Abu Dawud, Sunan at-Turmudzi, Sunan an-Nasai, Sunan Ibn Majah, Sunan ad-Darimi, Muwatta Malik, and Musnad Imam Ahmad bin Hanbal in the form of digital data Lidwa Reader Software Book 9 Imam Hadith. The findings of the study stated that the meaning of the word Rabb includes: creating, nurturing, maintaining, teaching, educating, and organizing. Thus, in an academic term, the word Rabb implies a manager or leader. Meanwhile, in the concept of comprehensive manager it contains at least 14 nomenclature denotations: planning, responsibility, organization, coordination, system of employee payroll, learning, resources, humanity, principle of making it easier for the manager to the employee, motivated to achieve optimal performance, preventing unproductivity, education participation, institutional costs, monitoring, and evaluation system. Each nomenclature has numerous hadiths that could serve

  1. Alternativen als Programm

    Directory of Open Access Journals (Sweden)

    Paulina Dobroć

    2018-03-01

    Full Text Available Der vorliegende Artikel soll einen Beitrag zu theoretischen Überlegungen einer Technikfolgenabschätzung (TA der Alternativen leisten. Ausgehend von der Annahme, dass TA seit ihrer Entstehung den Anspruch auf die Entwicklung von (technischen Alternativen erhoben hat, wird hier der Versuch unternommen, die Rolle der TA im Rahmen aktueller Innovationsprozesse zu reflektieren und (neu zu definieren. Dies scheint vor allem im Hinblick auf aktuelle gesellschaftliche Herausforderungen notwendig. Zu diesem Zweck wird eine Grundannahme Lothar Hacks über das Verhältnis von Gesellschaft und Technik herangezogen. Seine Annahme besagt, dass die kontinuierliche Überführung von sozialen Problemen und Leitbildern in enge technische Lösungsansätze in hochindustrialisierten Ländern dominant und Teil der aktuellen gesellschaftlichen Probleme ist. Diese These wird im vorliegenden Artikel im Hinblick auf einen Perspektivenwechsel als Ausgangspunkt eines zukünftigen Forschungsprogramms der TA fruchtbar gemacht. Hierbei bildet das Denken in Alternativen von gesellschaftlichen Zukünften den zentralen Fokus.

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

    Directory of Open Access Journals (Sweden)

    Amrah Muhammad Kasim

    2015-12-01

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

  3. Messy Relationships

    DEFF Research Database (Denmark)

    Feldt, Liv Egholm

    “The common good” is a contested concept both presently and historically. The contestation takes place both through definitions and concrete practices of gift-giving at the messy and blurred intersection between state, marked and civil society. From the Danish constitution of 1849 until today......-giving as a continuous and negotiated process between actors whose actions and utterances have implications for the relationships between state, market and civil society. The paper first outlines a theoretical and methodological approach that connects ANT and microhistory with conceptual history and focuses on how...

  4. 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

  5. Undulators at the ALS

    International Nuclear Information System (INIS)

    Hoyer, E.; Akre, J.; Chin, J.

    1994-07-01

    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

  6. Bilder machen - Fotografie als Praxis

    OpenAIRE

    Bove, Jens; Kaschek, Bertram

    2010-01-01

    In der Ausstellung „Bilder machen – Fotografie als Praxis“ stellt die Deutsche Fotothek der SLUB Dresden in Kooperation mit der Universitätssammlung Kunst+Technik die Fotografie als vielgestaltige kulturelle Praxis vor. Fast alle Exponate stammen von der Deutschen Fotothek, deren Bestand mehr als drei Mio. Aufnahmen umfasst. Die Ausstellung wird von einer öffentlichen Ringvorlesung begleitet, in der weitere Gebrauchsweisen der Fotografie in den Blick genommen werden. Außerdem ist ein Katalog ...

  7. Half life of 26Al

    International Nuclear Information System (INIS)

    Norris, T.L.; Gancarz, A.J.; Rokop, D.J.; Thomas, K.W.

    1983-01-01

    The half-life of 26 Al has been redetermined because of suggestions of an error in the accepted value based on its use in calculating 21 Ne production rates from cosmic rays in meteorites. Two solutions of 26 Al were analyzed for the specific radioactivity and mass spectrometric determination of the 26 Al concentration. The half-life obtained for 26 Al was 7.05 x 10 5 years +- 3.7% at the two sigma level. This is identical to the accepted value of 7.16 x 10 5 years and indicates that problems with the 21 Ne production rate is not due to an erroneous half-life

  8. Local heteroepitaxy as an adhesion mechanism in aluminium coatings cold gas sprayed on AlN substrates

    International Nuclear Information System (INIS)

    Wüstefeld, Christina; Rafaja, David; Motylenko, Mykhaylo; Ullrich, Christiane; Drehmann, Rico; Grund, Thomas; Lampke, Thomas; Wielage, Bernhard

    2017-01-01

    Cold gas sprayed Al coatings deposited onto wurtzitic AlN substrates show excellent adhesion. As a possible adhesion mechanism, the local heteroepitaxy between Al and AlN was considered and verified experimentally in Al coatings, which were deposited using magnetron sputtering or cold gas spraying on single-crystalline and polycrystalline AlN substrates. Analysis of the local orientation relationships at the Al/AlN interfaces revealed that preferentially such lattice planes of Al align parallel with the upright lattice planes of AlN, which possess similar interplanar distances. The matching lattice planes in the Al coatings grew as continuations of the lattice planes in the AlN substrates. In all samples under study, the parallel alignment of the lattice planes {220} Al and {110} AlN was found. Additional orientation relationships between Al and AlN arose if parallel lattice planes with similar interplanar spacing could be found in both counterparts via rotation of the lattice planes {220} Al around their normal direction. Still, the oriented growth of Al on AlN is only possible if Al atoms in the deposited coatings are mobile enough to rearrange along the AlN surface. Whereas the mobility of Al atoms in a magnetron sputtering process is expected to be sufficiently high, the intrinsic mobility of Al atoms in the cold gas sprayed particles is anticipated to be low. However, the auxiliary microstructure analyses have shown that local recrystallization and partial melting are two phenomena, which can facilitate the rearrangement of Al atoms within the cold gas sprayed coating.

  9. length-weight relationship of hepsetus odoe in lapai - agaie ...

    African Journals Online (AJOL)

    Ibrahim Usman

    biometric relationship so that data collected from the field can be transform into appropriate indices (Ecoutin et al., 2005). Length and weight are two useful parameters used especially in fisheries assessment. This relationship known as length-weight relationship (LWR), is commonly used in the analysis of fisheries data.

  10. Novel hysteresis effects in Nb/AlOx/Al/AlOx/Nb tunnel junctions

    International Nuclear Information System (INIS)

    Blamire, M.G.; Kirk, E.C.G.; Somekh, R.E.; Evetts, J.E.

    1991-01-01

    Measurements on current-biased Nb/AlO x /Al/AlO x /Nb double tunnel junction devices with very thin central Al layers show a novel double hysteretic structure in the subgap region. Similar junction structures have previously exhibited very large nonequilibrium effects; the effects reported here appear close to and above the equilibrium critical temperature of Al. A model is presented in which the hysteresis is shown to arise from a transition from finite to zero voltage across one barrier on increasing current, due to the nucleation of an inhomogeneous state in the ultrathin central Al layer in which normal and superconducting states coexist. This reverse switching effect is shown to arise from the self-shunting effect of low-gap regions. Predictions of this model are shown to agree with the experimental data

  11. 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...... of residual deposits from technology in organizations and its effect on individuals ability to connect to one another. Based on the case study the paper describes indications and suggests potential implication hereof. Given the inherent enhancement possibilities of technology our expectation for entertainment......-­‐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...

  12. Relationships matter

    DEFF Research Database (Denmark)

    Nyanja, Tabitha Alexandria Njeri; Tulinius, Charlotte

    2017-01-01

    Efforts to eliminate mother-to-child transmission of HIV in Tanzania are guided by a four-prong strategy advocated by the World Health Organization (WHO). Prong 2, prevention of unintended pregnancies among women living with HIV, has, however, received the least attention and contraceptive use...... to prevent unintended pregnancies remains low. This study explored the perceived barriers to the use of modern methods of contraception, and factors influencing contraceptive choice among HIV-positive women in urban Dar-es-Salaam, Tanzania. A qualitative multi-site study was conducted, utilising in......-depth interviews and focus group discussions with 37 sexually active HIV-positive women aged between 20 and 44 years, attending three health facilities within Dar-es-Salaam. The theoretical framework was a patient centred model. Four barriers were identified: the influence of the women’s spousal relationships...

  13. 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.

  14. Asowata et al (10).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    (Nyarko et al., 2006; Ajmone-Marsan et al., 2008). Sediment contamination and subsequent pollution resulting ..... leachate, such as alloys for corrosion resistant equipment and batteries. The third group consists of U .... Abimbola, A.F., Asaah, V.A. and Suh, C.E, 2006. Heavy Metal Concentrations and. Distribution in Surface ...

  15. 123 - 128 Sadau et al.

    African Journals Online (AJOL)

    User

    neutrophil count in response to WRS for 3.5 hours. Some of the haematological values (PCV, RBC,. WBC, Hb, neutrophils ... homeostasis (Anil et al., 2010). Stress induces organ injury causing diseases, including, gastric ulcers ... immune systems (Ebulunlomoet al., 2012). Cytokines and cortisol play an important role in the.

  16. 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

    2015-09-22

    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 ~ V(n), 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.

  17. Deformation mechanisms of nanotwinned Al

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinghang [Texas A & M Univ., College Station, TX (United States)

    2016-11-10

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  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. SANANDO AL SANADOR

    Directory of Open Access Journals (Sweden)

    Juan Pablo Acuña, Dr.

    2017-09-01

    Full Text Available RESUMEN: La dependencia o adicción a sustancias de uso profesional es un problema que puede afectar gravemente a médicos de diferentes especialidades. En la anestesiología hay mayor riesgo de dependencia a opioides e hipnóticos que en otras especialidades y puede llegar a afectar al 1% de los médicos anestesiólogos.La fisiopatología del trastorno por uso de sustancias tiene hechos comunes para diferentes drogas. Interactúan la vulnerabilidad genética y factores psicosociales como predisponentes y los efectos psicobiológicos de la sustancia como factor gatillante. En el caso de los anestesiólogos, la sustancia se encuentra en el lugar de trabajo y por lo tanto, el individuo está constantemente expuesto.Una disfunción previa del sistema de recompensa en el circuito mesocorticolímbico o causada por la exposición a la sustancia adictiva es la piedra central de la neurobiología de las adicciones. Los opioides, anfetaminas, canabinoides, alcohol y nicotina, son algunas de las sustancias exógenas que activan el circuito y causan inicialmente un efecto hedónico que reforzará la conducta por repetir la experiencia. Con el tiempo la interacción con la droga será para evitar los síntomas de abstinencia.Dada la exposición laboral de los anestesiólogos, es necesario prevenir, detectar y tratar precozmente a quienes están abusando de sustancias durante su ejercicio profesional.Por las características de estos fármacos, aspectos psicológicos especiales de los médicos y el contexto laboral se hace necesario un tratamiento especializado y en anestesiólogos la reinserción laboral debe ser un proceso controlado, gradual y con un seguimiento prolongado. SUMMARY: Prescription drugs dependence seriously impairs doctors from differents fields of medicine. Anesthesiology has greater risk than other specialties to opioids and hypnotics dependence, with prevalence up to 1%.Substances use disorder has common mechanisms of disease regardless

  20. Characteristics of CeCoIn5/Al/AlOx/Nb and CeCoIn5/Al/AlOx/Al tunnel junctions

    International Nuclear Information System (INIS)

    Nevirkovets, I.P.; Chernyashevskyy, O.; Petrovic, C.; Hu Rongwei; Ketterson, J.B.; Sarma, Bimal K.

    2009-01-01

    We report characteristics of CeCoIn 5 /Al/AlO x /Nb and CeCoIn 5 /Al/AlO x /Al tunnel junctions fabricated on the (0 0 1) surface of CeCoIn 5 crystal platelets. The main result of this work is the observation of a low Josephson current (as compared with that expected from the Ambegaokar-Baratoff formula), which is consistent with idea that the order parameter in the heavy-fermion superconductor CeCoIn 5 has unconventional pairing symmetry.

  1. TAX LEGAL RELATIONSHIP

    OpenAIRE

    Narcis Eduard MITU; Alia Gabriela DUŢĂ

    2012-01-01

    The legal relationship is a patrimonial or non-patrimonial social relationship regulated by a rule of law. Any legal relationship is a social relationship, but not any social relationship is a legal relationship. The law maker has the power to select, of the multitude of human relationships, those who gives importance in terms of legal perspective, encoding them through legal regulations.

  2. Fragility and structure of Al-Cu alloy melts

    International Nuclear Information System (INIS)

    Lv Xiaoqian; Bian Xiufang; Mao Tan; Li Zhenkuan; Guo Jing; Zhao Yan

    2007-01-01

    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

  3. The Influence of Alloying and Processing on the Microstructure and Properties of Beta-NiAl

    National Research Council Canada - National Science Library

    Kaufman, M

    1998-01-01

    The overall objective of this program was to provide a fundamental understanding of the effects of alloying and processing on the microstructure-property-processing relationships of monolithic b-NiAl...

  4. AL SAHLI, AA; OKOLI, JU

    African Journals Online (AJOL)

    ADOWIE PERE

    bioline.org.br/ja. The Use of Soil Palynomorphs in Forensics. *. 1. ABDULRAHAMAN, AA;. 2. AL SAHLI, AA;. 1. OKOLI, JU. 1Applied Plant Anatomy and Wood Technology Laboratory, Department of Plant Biology, University of Ilorin, Ilorin, Nigeria.

  5. RETRACTED ARTICLE: Investigation on heterogeneous nucleation of MgAl2O4 in Al-Mg alloys

    Science.gov (United States)

    Haghayeghi, R.; Kapranos, P.

    2015-05-01

    This work investigates the mechanisms of grain refinement of Al-Mg alloys through ultrasonic treatment and varying Mg content. MgAl2O4 particles display an equiaxed and faceted morphology with {111} planes and when exposed to {111} of α-Al, can act as heterogeneous and potent nuclei for aluminium. Intensive vibrations by ultrasonic treatment lead to significant grain refinement through effective dispersion of MgAl2O4 particles. The equiaxed and faceted morphology of MgAl2O4 along with a well-defined cube-on-cube orientation relationship (1bar 11)[110] MgAl2O4//(1bar 11)[110] α-Al, provide improved refinement. Furthermore, multiplication of solidification sites by the ultrasonic pulses enhances heterogeneous nucleation. The resulting improved grain refinement relates in all probability to the increased nucleation sites, due to grain multiplications and wetting of impurities, the lowering of surface tension due to the segregation of magnesium to the surface of liquid aluminium, the appropriate growth restriction factor and the low lattice mismatch coupled with strong dispersion of oxides.The filtration test confirms these particles as potent refiners.

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

    International Nuclear Information System (INIS)

    Matsumura, Atsuki; Takahashi, Toru; Kurakado, Masahiko

    1992-01-01

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

  7. Al-induced root cell wall chemical components differences of wheat ...

    African Journals Online (AJOL)

    Root growth is different in plants with different levels of Al-tolerance under Al stress. Cell wall chemical components of root tip cell are related to root growth. The aim of this study was to explore the relationship between root growth difference and cell wall chemical components. For this purpose, the cell wall chemical ...

  8. Grain refinement efficiency and mechanism of aluminium carbide in Mg-Al alloys

    International Nuclear Information System (INIS)

    Lu, L.; Dahle, A.K.; StJohn, D.H.

    2005-01-01

    Detailed microscopic examination using optical and electron microscopes suggests that Al 4 C 3 , often observed in the central regions of magnesium grains on polished sections, is a potent substrate for primary Mg. Calculations of the crystallographic relationships between magnesium and Al 4 C 3 further support the experimental observations

  9. Tafsir al-Tahrir wa al Tanwir Karya Muhammad Al-Thahrir ibn Asyur

    Directory of Open Access Journals (Sweden)

    Jani Arni

    2011-06-01

    Full Text Available Ibn ‘Âsyûr merupakan salah seorang mufasir di zaman modern yang menghasilkan sebuah kitab tafsir yang diberi nama “al-Tahrîr wa al-Tanwîr”. Kitab tafsir ini menggunakan corak ilmiah dalam menjelaskan makna ayat al-Quran, meskipun corak tersebut masih kontroversi tentang kebolehannya. Namun, ternyata penafsiran yang dilakukan oleh Ibn ‘Âsyûr tidak mendapatkan kritikan dari ulama lainnya dalam hal penggunaan ilmu pengetahuan modern. Karena, Ibn ‘Âsyûr menggunakan corak tersebut diawali dengan pengkajian kebahasaan, selanjutnya baru dijelaskan teori-teori ilmu pengetahuan yang berkaitan dengan ayat, sehingga tidak memberi kesan pemaksaan teori ilmu pengetahuan terhadap makna ayat al-Quran.

  10. KONSELING PERKAWINAN DALAM PERSPEKTIF AL-QUR’AN

    Directory of Open Access Journals (Sweden)

    Abdul Basit

    2017-02-01

    source in the development of counseling because in the Qur'an, there are a lot of discussion about people and their relationships with God, among others, and with the universe. The views of the Al-Qur’an on human being comprehensivelyand it can be an alternative to cover the weaknesses in some of the existing counseling approach. Marriage counseling in the Qur'an includes the process of education, advocacy, development, and problem solving of marital. Furthermore, marriage counseling in the Qur'an also does not separate between family counseling, individual counseling and marriage counseling itself. Everything becomes a unity in marriage counseling, begins from premarital education, the process of marriage, after marriage, the family formation, to the process of divorce (if it happens. The approach of the Qur'an in performing marriage counseling is comprehensive and multi-functional, i.e, a combination of approaches premarital counseling, structured modalities, multifamily group counseling, and marital therapy. Key words: counseling, marriage, Al-Qur’an, family, and Islam

  11. Bound and resonant surface states at the (110) surfaces of AlSb, AlAs, and AlP

    International Nuclear Information System (INIS)

    Beres, R.P.; Allen, R.E.; Buisson, J.P.; Bowen, M.A.; Blackwell, G.F.; Hjalmarson, H.P.; Dow, J.D.

    1982-01-01

    The dispersion curves E(k-bar) have been calculated for bound and resonant (110) surface states of AlSb, AlAs, and AlP. AlSb is predicted to have no surface states within the bulk fundamental band gap, but AlAs and AlP are predicted to have surface state band minima which are very near the conduction band edge, and could lie either within the gap or immediately above the edge

  12. 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.

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Misbakhudin Misbakhudin

    2017-06-01

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

  15. The Cl Functionalized Aluminum Nitride (AlN) and Aluminum Phosphide (AlP) Nanocone Sheets as Hydrogen Selenide (H2Se) Sensor: a Density Functional Investigation.

    Science.gov (United States)

    Abrishamifar, Seyyed Milad; Heidari, Negar; Razavi, Razieh; Lariche, Milad Janghorban; Najafi, Meysam

    2018-03-01

    The adsorption of H2Se molecule on AlN-NCS and AlP-NCS surfaces were investigated by using of DFT calculations. The potentials of Cl-functionalized AlN-NCS and AlP-NCS for H2Se adsorption were examined. All processes of H2Se-adsorption on considered nanocone sheets were exothermic reactions. The calculated |Ead| amount of complex H2Se with AlP-NCS was higher than AlN-NCS. The functionalization of considered nanocone sheets with Cl atom increase |Ead| amount of H2Se. Results reveal that, obtained Ead amounts of considered nanocone sheets have linear relationships with corresponding orbital energy amounts. Finally, the novel nanocone sheets with higher efficiency to adsorption of H2Se can be proposed.

  16. Fenomenologi Niat : Antara al-Ghazali dan al-Sayuthi

    Directory of Open Access Journals (Sweden)

    Mujiburrahman Mujiburrahman

    2011-12-01

    Full Text Available The evolusionist and functionalist approaches to religion are generally considered less sympathetic if not antipathy to religious phenomena. This is why, some western scholars propose another approach to study religion called ‘phenomenological’ approach. There have been a number of phenomenological studies of religion, but mostly not of  Islam. This article tries to fill in the gap by describing and analyzing the Islamic conception of intention (niyyah developed by al-Sayuthi and al-Ghazali. As a jurist, al-Sayuthi explores different formal rules on niyyah in Islamic jurisprudence, while al-Ghazali as a Sufi, tries to deepen the meaning of niyyah in relation to one’s sincerity to God. Apart from this difference, both conceptions of niyya indicate that as believers, Muslims always attempt to live in the sacred space and time, and make their speech and deed sacred based on the niyyah. Thus, niyya is the very basis of Muslim religious life.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-05

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

  18. La neuroplasticidad aplicada al deporte

    OpenAIRE

    Fernández, Hernán

    2015-01-01

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

  19. estigma tolerable al estigma intolerable

    Directory of Open Access Journals (Sweden)

    Nelson Arteaga Botello

    2006-01-01

    cristalización pasa por dos referentes de interacción y relación social al interior del espacio escolar. El primero está constituido por parámetros de normalidad y anormalidad a partir de la localización de estigmas. El segundo se encuentra, a contrapelo de la tendencia anterior, tratando de diluir los efectos de los estigmas al señalarlos como una práctica de tipificación social intolerable o inaceptable.

  20. Al-Biruni's mechanical calendar.

    Science.gov (United States)

    Hill, D. R.

    This paper is concerned with a mechanical calendar described by the great scientist al-Biruni, who died in 440/1048. The description occurs in a book devoted to the construction of various types of astrolabe and related instruments. The Arabic text presented in this paper was prepared from three manuscripts. This is preceded by a brief introduction which gives a sketch of the life and works of al-Biruni together with information about the provenance and contents of the three manuscripts. The text is followed by an English translation and the paper concludes with a technical commentary.

  1. De la contingencia al destino

    Directory of Open Access Journals (Sweden)

    Heller, Agnes

    1991-10-01

    Full Text Available Not available.

    La modernidad no ha podido dar respuesta al problema de la contingencia histórica, El texto muestra, por medio de metáforas, que el abandono necesario de esta cuestión no significa que estemos abocados al relativismo respecto a la contingencia existencial. La contingencia existencial, individual, sigue presente en la vida de todo individuo. Se sostiene que podemos dar un destino a nuestras vidas, y ésta es la tarea principal del filósofo.

  2. Tailoring ultrafine grained and dispersion-strengthened Ti2AlC/TiAl ...

    Indian Academy of Sciences (India)

    Abstract. In situ Ti2AlC/TiAl composite was fabricated by hot-pressing method via the reaction system of Ti3AlC2 and Ti-Al pre-alloyed powders at low temperature of 1150◦C. The composite mainly consisted of TiAl, Ti3Al and. Ti2AlC phases. Fine Ti2AlC particles were homogeneously distributed and dispersed in the matrix.

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

    Indian Academy of Sciences (India)

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

  4. ¿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.

  5. Universal Server - Informix al CILEA

    OpenAIRE

    Camnasio, Maurizio; Trombetta, Laura

    1998-01-01

    Viene presentato il nuovo prodotto Universal Server di INFORMIX installato al CILEA su macchina SUN Server ultra-2. Si tratta di un database relazionale ad oggetti capace di memorizzare e gestire in modo efficace dati alfanumerici, immagini, video, pagine Web e dati diversi definiti dall'utente, all'interno di un'unico repository.

  6. Ajikah et al (11).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Faculty of Science, Senate Building and New Hall respectively. A total of 3,495 palynomorphs belonging to ... dust mites, insect debris and organic dust present in the air (Hyde, 1972). Another point of ..... Table 2: Percentage Composition of Total Pollen Counts from Senate Building. Ajikah et al.: Palynological Survey of ...

  7. Das "Al-Capone"-Prinzip

    OpenAIRE

    Wirtz, Georg

    2006-01-01

    Das "Al-Capone"-Prinzip : Risiken u. Chancen e. "Gewinnabschöpfung durch Besteuerung" nach d. Steuerverkürzungsbekämpfungsgesetz. - Baden-Baden : Nomos-Verl.-Ges., 2006. - 300 S. - (Schriftenreihe zum deutschen, europäischen und internationalen Wirtschaftsstrafrecht ; 3). - Zugl.: Augsburg, Univ., Diss., 2005

  8. 76 - 81_Hayatu et al.

    African Journals Online (AJOL)

    User

    flowering plants that belong to the family. Scrophulariaceae that affect cowpea productions in dry savana (Omoigui et al., 2007). The productivity of cowpea in dry region is hampered by low yield due to constraints , which include insects pest, disease, drought, low soil fertility and temperature extremes. But among the most ...

  9. Falebita et al (4).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    These indicate that they have above minimum TOC to generate hydrocarbon .... exploration. At the deep-water toe of the delta, a series of large fold and thrust belts composed of thrust faults and fault-related folds have been reported (Wu and Bally, 2000; Corredor et al., ..... continental margins: American Geophysical.

  10. 180 - 184_ Farouk et al.,

    African Journals Online (AJOL)

    User

    tals in environmental samples in reported,(Georgina et al., 2013; ... Sample collection. The animal products were purchased directly and randomly from four different markets(Samaru, Sabon. Gari, Tudun Wada and Zaria city markets) of Zaria and its environing. Sample preparation and analysis. The samples were prepared ...

  11. 81 - 87 Iwuala et al.

    African Journals Online (AJOL)

    User

    Okujagu et al., 2006). The root of the plant is used for the treatment of chest disease and skin ..... Openshaw K (1986). Concepts and Methods for collecting and compiling statistics in Biomass used as Energy. UN statistical office New York. USA.

  12. Al Zubarah - eine vergessene Legende

    DEFF Research Database (Denmark)

    Kinzel, Moritz

    2014-01-01

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

  13. Oke et al (5).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    means they are perfectly positively correlated; while its correlation with Krishna Rao Formula is. (+0.999), which means they are highly positively correlated. Oke et al.: Comparative Analysis of Groundwater Recharge Estimation Value. Table 7: Inter-Item Correlation Matrix of Annual Areal Recharge. Modified. Chaturvedi ...

  14. Jacob et al (21).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    1Department of Chemistry, Federal University of Technology, Minna, Nigeria. 2Department of Chemistry, University of Abuja, PMB 117, Abuja, Nigeria ... pesticides, use of polluted water for irrigation, waste disposal, industrial and mining activities. (Ashish et al., 2013). Massive and regular chemical analysis of farmland soil ...

  15. Oyebola et al (23).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    3+ described elsewhere (Oyebola et al., 2010). Ho absorption peaks were obtained from transmission studies carried out with a Cary 5000. UV-VIS-NIR spectrophotometer and corresponding absorption coefficients deduced using the Beer-Lambert law. Spectral emission measurements were carried out using the schematic ...

  16. Elueze et al (6).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Appraisal of the functional potential of the marble based on mineralogical, chemical, physical and mechanical characteristics indicate that Obajana marble ... varying stages of geological, engineering and economic appraisals. It is noteworthy ... N-S structural trends of the basement rocks. (Grants, et al.,1972; Turner, 1983).

  17. Dankwah et al (12).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    breakfast cereals (Tareke et al., 2002). Coultate. (2009), has reported that prolonged heating of legumes .... (2005). A mass of 1.0 g portion of defatted treated. Cajanus cajan sample was measured into a 50 mL ... added and the mixture was vortex briefly to disperse test portion in 30 mL of 70 % acetonitrile. A volume of 500 ...

  18. Idowu et al (19).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    lakes, rivers and canals) and lateral or vertical inter- aquifer flow (MacDonald et al., 2005). Typically, it travels vertically ... been used for the evaluation of Opeki drainage. Basin, also in southwestern Nigeria, by Idowu and ... Nigeria in which the drainage basins of the study area are located. The daily discharge values were.

  19. Kringloop als basis van bedrijfsvoering

    NARCIS (Netherlands)

    Linde, van der A.

    2007-01-01

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

  20. 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.

  1. 185 -190 _ Iwuala et al.

    African Journals Online (AJOL)

    User

    in plants. Keywords: Catalase, drought, oxidative stress, seedlings, Zea mays. INTRODUCTION. Water is an important requirement for biochemical processes in all forms of life. Drought stress (also referred to as water or osmotic stress) limits the amount of water available for use in metabolic processes (Xiong et al., 2002).

  2. Laniyan et al (16).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    they are hazard-resistant construction materials. (Hodgson et al., 2000) These geo-materials which are also known as geotechnical materials can be found between the ground surface and the rock and influences the structural damage examples of such are marble, clay, soil, activated charcoal/carbon, this materials can ...

  3. Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

    International Nuclear Information System (INIS)

    Hori, Y.; Yatabe, Z.; Hashizume, T.

    2013-01-01

    We have investigated the relationship between improved electrical properties of Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) and electronic state densities at the Al 2 O 3 /AlGaN interface evaluated from the same structures as the MOS-HEMTs. To evaluate Al 2 O 3 /AlGaN interface state densities of the MOS-HEMTs, two types of capacitance-voltage (C-V) measurement techniques were employed: the photo-assisted C-V measurement for the near-midgap states and the frequency dependent C-V characteristics for the states near the conduction-band edge. To reduce the interface states, an N 2 O-radical treatment was applied to the AlGaN surface just prior to the deposition of the Al 2 O 3 insulator. As compared to the sample without the treatment, the N 2 O-radical treated Al 2 O 3 /AlGaN/GaN structure showed smaller frequency dispersion of the C-V curves in the positive gate bias range. The state densities at the Al 2 O 3 /AlGaN interface were estimated to be 1 × 10 12  cm −2  eV −1 or less around the midgap and 8 × 10 12  cm −2  eV −1 near the conduction-band edge. In addition, we observed higher maximum drain current at the positive gate bias and suppressed threshold voltage instability under the negative gate bias stress even at 150 °C. Results presented in this paper indicated that the N 2 O-radical treatment is effective both in reducing the interface states and improving the electrical properties of the Al 2 O 3 /AlGaN/GaN MOS-HEMTs

  4. Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

    Science.gov (United States)

    Hori, Y.; Yatabe, Z.; Hashizume, T.

    2013-12-01

    We have investigated the relationship between improved electrical properties of Al2O3/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) and electronic state densities at the Al2O3/AlGaN interface evaluated from the same structures as the MOS-HEMTs. To evaluate Al2O3/AlGaN interface state densities of the MOS-HEMTs, two types of capacitance-voltage (C-V) measurement techniques were employed: the photo-assisted C-V measurement for the near-midgap states and the frequency dependent C-V characteristics for the states near the conduction-band edge. To reduce the interface states, an N2O-radical treatment was applied to the AlGaN surface just prior to the deposition of the Al2O3 insulator. As compared to the sample without the treatment, the N2O-radical treated Al2O3/AlGaN/GaN structure showed smaller frequency dispersion of the C-V curves in the positive gate bias range. The state densities at the Al2O3/AlGaN interface were estimated to be 1 × 1012 cm-2 eV-1 or less around the midgap and 8 × 1012 cm-2 eV-1 near the conduction-band edge. In addition, we observed higher maximum drain current at the positive gate bias and suppressed threshold voltage instability under the negative gate bias stress even at 150 °C. Results presented in this paper indicated that the N2O-radical treatment is effective both in reducing the interface states and improving the electrical properties of the Al2O3/AlGaN/GaN MOS-HEMTs.

  5. Lattice stabilities, mechanical and thermodynamic properties of Al3Tm and Al3Lu intermetallics under high pressure from first-principles calculations

    Science.gov (United States)

    Xu-Dong, Zhang; Wei, Jiang

    2016-02-01

    The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L12 structure Al3Tm and Al3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al3Tm and Al3Lu keep their dynamical stabilities in L12 structure up to 100 GPa. The elastic properties and Debye temperatures for Al3Tm and Al3Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the three-dimensional (3D) curved surface of Young’s modulus. The calculated results show that Al3Tm and Al3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al3Tm and Al3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications. Project supported by the Scientific Technology Plan of the Educational Department of Liaoning Province and Liaoning Innovative Research Team in University, China (Grant No. LT2014004) and the Program for the Young Teacher Cultivation Fund of Shenyang University of Technology, China (Grant No. 005612).

  6. 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...

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  10. Microstructure/Oxidation/Microhardness Correlations in Gamma-Based and Tau-Based Al-Ti-Cr Alloys

    Science.gov (United States)

    Brady, Michael P.; Smialek, J. L.; Humphrey, D. L.

    1994-01-01

    The relationships between alloy microstructure and air oxidation kinetics and alloy microstructure and microhardness in the Al-Ti-Cr system for exposures at 800 C and 1000 C were investigated. The relevant phases were identified as tau (Ll2), gamma (LIO), r-Al2Ti, TiCrAl (laves), and Cr2AI. Protective alumina formation was associated with tau, Al-rich TiCrAl, and gamma/TiCrAl mixtures. Brittleness was associated with the TiCrAl phase and tau decomposition to A12Ti + Cr2AI. It was concluded that two-phase gamma + TiCrAl alloys offer the greatest potential for oxidation resistance and room temperature ductility in the Al-Ti-Cr system.

  11. 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.

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

    OpenAIRE

    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, and Liang-mo

    2015-01-01

    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 volt...

  13. AlSb/InAs/AlSb quantum wells

    Science.gov (United States)

    Kroemer, Herbert

    1990-01-01

    Researchers studied the InAs/AlSb system recently, obtaining 12nm wide quantum wells with room temperature mobilities up to 28,000 cm(exp 2)/V center dot S and low-temperature mobilities up to 325,000 cm(exp 2)/V center dot S, both at high electron sheet concentrations in the 10(exp 12)/cm(exp 2) range (corresponding to volume concentrations in the 10(exp 18)/cm(exp 2) range). These wells were not intentionally doped; the combination of high carrier concentrations and high mobilities suggest that the electrons are due to not-intentional modulation doping by an unknown donor in the AlSb barriers, presumably a stoichiometric defect, like an antisite donor. Inasmuch as not intentionally doped bulk AlSb is semi-insulating, the donor must be a deep one, being ionized only by draining into the even deeper InAs quantum well. The excellent transport properties are confirmed by other observations, like excellent quantum Hall effect data, and the successful use of the quantum wells as superconductive weak links between Nb electrodes, with unprecendentedly high critical current densities. The system is promising for future field effect transistors (FETs), but many processing problems must first be solved. Although the researchers have achieved FETs, the results so far have not been competitive with GaAs FETs.

  14. Jongerenwerk als werkplaats voor professionalisering

    Directory of Open Access Journals (Sweden)

    Judith Metz

    2012-03-01

    met wetenschappelijke experimentele kennis als norm, is dat zij niet altijd goed aansluiten bij de complexiteit en flexibiliteit van de uitvoeringspraktijk. Vraag is: wat dan wel? In Amsterdam richten opleidingen en werkveld in 2008 Youth Spot op, het onderzoek- en praktijkcentrum voor jongerenwerk, met als doel om gezamenlijk te werken aan de profilering, professionalisering en praktijkontwikkeling van het jongerenwerk. Dit artikel belicht de aanleiding voor het ontstaan van Youth Spot, de structuur van de samenwerking, de ervaringen met de wijze van samen werken en de meerwaarde voor de professionalisering van het grootstedelijk jongerenwerk. Daarmee biedt dit artikel enerzijds een kijkje in de keuken van het (grootstedelijke jongerenwerk en anderzijds biedt zij inzicht in ervaringen met alternatieve professionalisering strategieën.

  15. Structure, thermal and mechanical properties of in situ Al-based metal matrix composite reinforced with Al2O3 and TiC submicron particles

    International Nuclear Information System (INIS)

    Yu Peng; Mei Zhi; Tjong, S.C.

    2005-01-01

    We report herein the structure and characterization of in situ Al-based metal matrix composites (MMCs) prepared from the Al-10 wt.% TiO 2 and Al-10 wt.% TiO 2 -1.5 wt.% C systems via hot isostatic pressing (HIP) at 1000 deg C and 100 MPa. The structure, morphology and thermal behavior of HIPed samples were studied by means of the X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results indicated that fined Al 2 O 3 particles and large intermetallic Al 3 Ti plates were in situ formed in the Al-10 wt.% TiO 2 sample during HIPing. However, the introduction of C to the Al-TiO 2 system was beneficial to eliminate large intermetallic Al 3 Ti plates. In this case, Al 2 O 3 and TiC submicron particles were in situ formed in the Al-10 wt.% TiO 2 -1.5 wt.% C sample. Three-point-bending test showed that the strength and the strain-at-break of the HIPed Al-10 wt.% TiO 2 -1.5 wt.% C sample were significantly higher than those of its Al-10 wt.% TiO 2 counterpart. The improvement was derived from the elimination of bulk Al 3 Ti intermetallic plates and from the formation of TiC submicron particles. DSC measurements and thermodynamic analyses were carried out to reveal the reaction formation mechanisms of in situ reinforcing phases. The DSC results generally correlated well with the theoretical predictions. Finally, the correlation between the structure-property relationships of in situ composites is discussed

  16. Examining the language and behavioural profile in FTD and ALS-FTD.

    Science.gov (United States)

    Saxon, Jennifer A; Thompson, Jennifer C; Jones, Matthew; Harris, Jennifer M; Richardson, Anna Mt; Langheinrich, Tobias; Neary, David; Mann, David Ma; Snowden, Julie S

    2017-08-01

    A proportion of patients with behavioural variant frontotemporal dementia (bvFTD) develop amyotrophic lateral sclerosis (ALS). It is currently unknown whether the behavioural and cognitive syndrome in bvFTD with ALS (ALS-FTD) is indistinguishable from that of bvFTD alone. A retrospective cohort of 241 patients with clinical diagnoses of bvFTD (n=185) or ALS-FTD (n=56) was examined with respect to behavioural, cognitive and neuropsychiatric symptoms. Features were rated as present or absent based on information recorded from clinical interviews and detailed neuropsychological assessment. A number of behavioural and affective changes were reported more frequently in bvFTD than ALS-FTD: social disinhibition (pALS-FTD than bvFTD (pALS-FTD than bvFTD: agrammatism (pALS-FTD. In particular, while changes in social behaviour are prominent in bvFTD alone, there may be a comparatively greater degree of language impairment in ALS-FTD. Prospective exploration of the pattern of differences between these groups will be essential. Identification of a distinct neuropsychological phenotype in ALS-FTD may have clinical implications for early diagnosis, disease management and care planning and theoretical implications for our understanding of the relationship between ALS and FTD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. National Study of Muscle Cramps in ALS in the USA.

    Science.gov (United States)

    Stephens, Helen E; Joyce, Nanette C; Oskarsson, Björn

    2017-02-01

    The objective of this study was to describe muscle cramps in an US sample of amyotrophic lateral sclerosis (ALS) patients. Utilizing an anonymous web based questionnaire we queried ALS patients regarding the severity, frequency, time-course, treatment of muscle cramps and their relationship to pain. The survey had 282 respondents with 92% reporting that they had cramps. For 20% of the sample, cramps were stated to be the presenting ALS symptom. Cramp severity was rated at a mean of 5.2/10 and the mean cramp frequency was 5.3 cramps per day. Cramp intensity and frequency did not correlate with duration or severity of ALS. Pain as measured with the Patient Reported Outcome Measurement Information System (PROMIS) pain scales was not statistically different from the US general population. Cramp severity and frequency significantly and positively correlated with the PROMIS pain scales. Patients with more severe cramps were more likely to use prescription medications for their cramps compared to patients with milder symptoms. Treatments directed at cramps were tried by 57%. In conclusion, cramps are a common symptom in ALS and it does not correlate with disease duration or severity. The severity of cramps is on average moderate and many patients try treatments.

  18. 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....

  19. Wear behaviour of Al 261

    Directory of Open Access Journals (Sweden)

    N. Mathan Kumar

    2016-03-01

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

  20. 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.

  1. 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".

  2. Stem cells therapy for ALS.

    Science.gov (United States)

    Mazzini, Letizia; Vescovi, Angelo; Cantello, Roberto; Gelati, Maurizio; Vercelli, Alessandro

    2016-01-01

    Despite knowledge on the molecular basis of amyotrophic lateral sclerosis (ALS) having quickly progressed over the last few years, such discoveries have not yet translated into new therapeutics. With the advancement of stem cell technologies there is hope for stem cell therapeutics as novel treatments for ALS. We discuss in detail the therapeutic potential of different types of stem cells in preclinical and clinical works. Moreover, we address many open questions in clinical translation. SC therapy is a potentially promising new treatment for ALS and the need to better understand how to develop cell-based experimental treatments, and how to implement them in clinical trials, becomes more pressing. Mesenchymal stem cells and neural fetal stem cells have emerged as safe and potentially effective cell types, but there is a need to carry out appropriately designed experimental studies to verify their long-term safety and possibly efficacy. Moreover, the cost-benefit analysis of the results must take into account the quality of life of the patients as a major end point. It is our opinion that a multicenter international clinical program aime d at fine-tuning and coordinating transplantation procedures and protocols is mandatory.

  3. 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...

  4. Strain dependence on polarization properties of AlGaN and AlGaN-based ultraviolet lasers grown on AlN substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Zachary, E-mail: zabryan@ncsu.edu; Bryan, Isaac; Sitar, Zlatko; Collazo, Ramón [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Mita, Seiji [HexaTech, Inc., 991 Aviation Pkwy., Suite 800, Morrisville, North Carolina 27560 (United States); Tweedie, James [Adroit Materials, 2054 Kildaire Farm Rd., Suite 205, Cary, North Carolina 27518 (United States)

    2015-06-08

    Since the band ordering in AlGaN has a profound effect on the performance of UVC light emitting diodes (LEDs) and even determines the feasibility of surface emitting lasers, the polarization properties of emitted light from c-oriented AlGaN and AlGaN-based laser structures were studied over the whole composition range, as well as various strain states, quantum confinements, and carrier densities. A quantitative relationship between the theoretical valence band separation, determined using k•p theory, and the experimentally measured degree of polarization is presented. Next to composition, strain was found to have the largest influence on the degree of polarization while all other factors were practically insignificant. The lowest crossover point from the transverse electric to transverse magnetic polarized emission of 245 nm was found for structures pseudomorphically grown on AlN substrates. This finding has significant implications toward the efficiency and feasibility of surface emitting devices below this wavelength.

  5. 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…

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

    International Nuclear Information System (INIS)

    Andoh, A.

    1997-01-01

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

  7. 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.

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  9. The preferential orientation and lattice misfit of the directionally solidified Fe-Al-Ta eutectic composite

    Science.gov (United States)

    Cui, Chunjuan; Wang, Pei; Yang, Meng; Wen, Yagang; Ren, Chiqiang; Wang, Songyuan

    2018-01-01

    Fe-Al intermetallic compound has been paid more attentions recently in many fields such as aeronautic, aerospace, automobile, energy and chemical engineering, and so on. In this paper Fe-Al-Ta eutectic was prepared by a modified Bridgman directional solidification technique, and it is found that microstructure of the Fe-Al-Ta eutectic alloy transforms from the broken-lamellar eutectic to cellular eutectic with the increase of the solidification rate. In the cellular eutectic structure, the fibers are parallel to each other within the same grain, but some fibers are deviated from the original orientation at the grain boundaries. To study the crystallographic orientation relationship (OR) between the two phases, the preferential orientation of the Fe-Al-Ta eutectic alloy at the different solidification rates was studied by Selected Area Electron Diffraction (SAED). Moreover, the lattice misfit between Fe2Ta(Al) Laves phase and Fe(Al,Ta) matrix phase was calculated.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, A. M., E-mail: abbasher@squ.edu.om [Sultan Qaboos University, College of Science (Oman); Abdallah, S. B. [University of Khartoum, Department of Geology, Faculty of Science (Sudan); Al-Rawas, A. D.; Al-Mabsali, F. N.; Widatallah, H. M.; Elzain, M. E.; Yousif, A. A. [Sultan Qaboos University, College of Science (Oman); Ericsson, T. [Uppsala University, Department of Physics and Material Sciences (Sweden); Annersten, H. [Uppsala University, Department of Earth Sciences (Sweden)

    2016-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Yunus Bıyık

    2016-03-01

    Full Text Available 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 of participative decision making did not differ in terms of age and marital status, there are differences between groups of gender, education level, tenure of office and titles

  13. 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.

  14. Gettysburg: Monumento al mundo libre

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1961-12-01

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

  15. Dialog als Kunst des Verweilens

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    Wann helfen Gespräche der ratsuchenden Person? Wenn folgendes beachtet wird: Der soziale Rahmen, der organisatorische/systemische Kontext, der Hintergrund, die Geschichte hinter der Situation, „Transformative Dialoge“ geben Orientierung und emotionalen Halt, führen zu Lösun-gen, verankern in der ....... Das Buch wendet sich an Professionelle, die ihre Fähigkeiten als kooperativ orientierter Ge-sprächspartner zu stärken wünschen, an Coaches, Mentoren, Psychologen, Führungskräfte, Pädagogen, Gesundheitspersonal, Seelsorger oder an den guten Freund....

  16. A melancolia em Al Berto

    OpenAIRE

    Camila Emanuele Martins de Souza

    2015-01-01

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

  17. Personalidad y tolerancia al dolor

    OpenAIRE

    JESÚS M.ª CARRILLO; SUSANA COLLADO; NIEVES ROJO

    2005-01-01

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

  18. 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

  19. [Relationship between defense mechanism and therapeutic alliance].

    Science.gov (United States)

    Laconi, S; Cailhol, L; Pourcel, L; Thalamas, C; Lapeyre-Mestre, M; Chabrol, H

    2015-10-01

    The therapeutic alliance can be defined as a collaborative relationship between the patient and the practitioner. It represents an essential component of the psychotherapeutic process (Ambresin et al., 2007; Cungi, 2006; Martin et al., 2000). Some authors suggest that a good alliance can have a favorable impact on the therapeutic success (Barber et al., 2000; Hubble, Duncan, & Miller 1999; Horvath & Luborsky, 1993; Horvath & Symonds, 1991). This alliance can be influenced by psychological and behavioral factors (Cungi, 2006) Thus, some defense mechanisms could prevent change or, on the contrary could facilitate adaptation (Ambresin et al., 2007) and have an impact on the therapeutic success (Muris & Merckelbach, 1996). However, the relationship between therapeutic alliance and defense mechanisms represents an insufficiently explored field (Ambresin et al., 2007; Cungi, 2006). The aim of the present study was to examine the relationship between therapeutic alliance and twenty defense mechanisms in a sample of French psychiatric patients, by differentiating results in men and women. We also examined the positive and the negative therapeutic alliance. Sixty patients aged from 18 to 58 (M=41.50; SD=11.03) completed the French versions of the Defense Style Questionnaire-40 (DSQ-40) and the Helping Alliance questionnaire-II (HAq-II). Therapeutic alliance was significantly associated with each defense style: mature (0.62), neurotic (0.45) Pdefense style was a significant predictor of therapeutic alliance (R(2) adj=36, F=12.39, β=0.65, Pdefenses, three neurotic defenses (reaction formation, pseudo-altruism, idealization) and four immature defenses (splitting, denial, somatization, passive aggression). Among men, three mature defenses were associated (anticipation, humor, sublimation), four neurotic (reaction formation, pseudo-altruism, idealization and undoing) and two immature (somatization and denial). The negative therapeutic alliance, in our total sample, was

  20. X-ray detection with Nb/Al/AlO{sub x}/Al/Nb tunneling junctions

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.; Finkbeiner, F.; Weber, K.J.; Lerch, P.; Zehnder, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ott, H.R. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1996-10-01

    A whole wafer fabrication procedure using selective etching of refractory materials to produce Nb- or Ta/Al/AlO{sub x}/Al/Nb tunneling detectors is discussed. Fabrication aspects and preliminary results are presented. (author) 2 figs., 5 refs.

  1. Experimental and thermodynamic investigation of Al-Cu-Nd ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Bai, W.M. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Jiang, Y. [Hunan Sushi Guangbo Testing Techniques Co. LTD, Changsha (China); Guo, Z.Y.; Zeng, L.J.; Tan, M.Y. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Meggs, C. [School of Metallurgy and Materials, The University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Zhang, L.G., E-mail: ligangzhang@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Liu, L.B., E-mail: pdc@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Jin, Z.P. [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China)

    2017-07-01

    The phase relationships in the Al–Cu-Nd ternary system at 673 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDS) in backscattered electron imaging (BSE) modes. The existence of six ternary Stoichiometric compounds, namely τ{sub 1}-Al{sub 8}Cu{sub 4}Nd, τ{sub 2}-Al{sub 9}Cu{sub 8}Nd{sub 2}, τ{sub 3}-Al{sub 6}Cu{sub 7}Nd, τ{sub 4}-Al{sub 2.4}Cu{sub 8.6}Nd, τ{sub 5}-Al{sub 3}CuNd, τ{sub 6}-AlCuNd, have been confirmed. A complete thermodynamic description of the Al–Cu-Nd ternary system coupled with the CALPHAD method is obtained based on experimental results and first-principles calculations. The calculated phase equilibria were in agreement with the available experimental data. - Highlights: • Phase relationships in the Al-Cu-Nd system has been systematically investigated. • 9 three-phase regions and 4 two-phase regions are confirmed. • A complete thermodynamic description of the Al-Cu-Nd system is obtained. • Results of first-principle calculation consist with thermodynamic calculation.

  2. 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.

  3. Machiavellianism, Relationship Satisfaction, and Romantic Relationship Quality

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2017-08-01

    Full Text Available Machiavellianism is characterised by a manipulative interpersonal style, willingness to exploit others, and a preference for emotionally detached relationships. The present studies investigate the extent to which Machiavellianism influences relationship satisfaction and romantic relationship quality. In Study 1, 194 heterosexual partnered women completed Machiavellianism and Relationship Satisfaction measures. Women with higher levels of Machiavellianism reported lower levels of relationship satisfaction. In Study 2, 132 heterosexual partnered women completed Machiavellianism, Trust, Commitment, Control, and Emotional Abuse scales. Women with higher levels of Machiavellianism perceived their partners to be less dependable, reported less faith in their partners, and were less willing to persist with the relationship than those with low levels of Machiavellianism. With regards to negative behavior, Machiavellianism predicted each form of control and emotional abuse investigated, such that those with high levels of Machiavellianism were more likely to engage in controlling behavior and emotional abuse. Findings have important implications for the prediction of romantic relationship quality and in particular for negative behavior such as control and abuse.

  4. Influence of Al addition on phase transformation and thermal stability of nickel silicides on Si(0 0 1)

    International Nuclear Information System (INIS)

    Huang, Shih-Hsien; Twan, Sheng-Chen; Cheng, Shao-Liang; Lee, Tu; Hu, Jung-Chih; Chen, Lien-Tai; Lee, Sheng-Wei

    2014-01-01

    Highlights: ► The presence of Al slows down the Ni 2 Si–NiSi phase transformation but significantly promotes the NiSi 2−x Al x formation. ► The behavior of phase transformation strongly depends on the Al concentration of the initial Ni 1−x Al x alloys. ► The Ni 0.91 Al 0.09 /Si system exhibits remarkably improved thermal stability, even after high temperature annealing for 1000 s. ► The relationship between microstructures, electrical property, and thermal stability of Ni(Al) silicides is discussed. -- Abstract: The influence of Al addition on the phase transformation and thermal stability of Ni silicides on (0 0 1)Si has been systematically investigated. The presence of Al atoms is found to slow down the Ni 2 Si–NiSi phase transformation but significantly promote the NiSi 2−x Al x formation during annealing. The behavior of phase transformation strongly depends on the Al concentration of the initial Ni 1−x Al x alloys. Compared to the Ni 0.95 Pt 0.05 /Si and Ni 0.95 Al 0.05 /Si system, the Ni 0.91 Al 0.09 /Si sample exhibits remarkably enhanced thermal stability, even after high temperature annealing for 1000 s. The relationship between microstructures, electrical property, and thermal stability of Ni silicides is discussed to elucidate the role of Al during the Ni 1−x Al x alloy silicidation. This work demonstrated that thermally stable Ni 1−x Al x alloy silicides would be a promising candidate as source/drain (S/D) contacts in advanced complementary metal–oxide-semiconductor (CMOS) devices

  5. KONSEP AKHLAK IMAM AL GHAZALI

    Directory of Open Access Journals (Sweden)

    Mohd Aji Isnaini

    2015-08-01

    Full Text Available Surely I was sent to perfect morals, Rasulullahn hadith illustrates how important it is morality that must-have for the survival of God on earth, the definition of morality according to al-Ghazali was "The phrase about living conditions in the soul, where all behavior stems from it with great ease without requires a process of thought and contemplation. Described good character if his mental condition into the source of good deeds, both in mind and the Shari'a. So conversely the bad deeds as well as violate the Shari'a is the moral condition of the poor. There are four elements that a good moral standards when these four elements are balanced so well that moral science, emotions, lust and fair. The theory of the method to educate the moral, as the expression of al-Ghazali. Normality on the moral health of the soul, and a tendency to stay away from normality is a disease or disorder.Thus, the antidote is Mujâhadah and Riyâdhatun Nafs as a way to treat it is to educate morality, by doing good deeds-deeds required by morality by improving life is to eliminate the various evil and bad morals, and won a moral virtue, good character, as how to treat limb pain is to eliminate the disease and seek recovery.

  6. con bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Adriana Mora Antó

    2005-01-01

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

  7. AL JAZEERA AND QATARI FOREIGN POLICY: A CRITICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Karim Pourhamzavi

    2016-01-01

    Full Text Available Our paper explores the Al-Jazeera network and its relationship to the state which set it up and continues to fund it.  We suggest that, while the network may provide perspectives for Western viewers that other large, but Western-owned networks do not, it is far from immune from the problems of state influence.  Behind a cultivated veneer of providing perspectives from 'the Arab street', the network reflects foreign policy perspectives of the Qatari state and the small elite which controls it.  This paper surveys Al-Jazeera Arabic news coverage (August 2014-August 2015 of conflict in Iraq and three AJA current affairs programmes coverage (January 2014-August 2015 of conflict in Iraq, Syria and Egypt.  The results indicate that, on foreign policy issues which the Qatari elite regards as particularly important, the network promotes the perspectives of the state.  The relationship between the Qatari state and Al-Jazeera also constrains the network's independence and objectivity.

  8. Resistance switching of thin AlOx and Cu-doped-AlOx films

    International Nuclear Information System (INIS)

    Wu, Ya-Ting; Jou, Shyankay; Yang, Ping-Jung

    2013-01-01

    Thin copper-doped aluminum oxide (Cu-doped-AlO x ) and AlO x films of about 5 nm thick were generated by oxidizing the surfaces of Al and Al-5 wt.% Cu (Al-Cu) films in an oxygen plasma. According to X-ray photoelectron spectroscopy analyses, these two oxide films were found to be deficient in oxygen and had gradient concentrations of Al and O. The oxide films were employed as resistor layers sandwiched between an Al top electrode and an Al or Al-Cu bottom electrode to form resistive memory devices. The devices demonstrated unipolar resistance switching between high resistance state and low resistance state (LRS), and their resistance ratios measured at + 0.2 V were around 10 5 . Furthermore, their current–voltage characteristics showed ohmic conduction with the resistance increasing with temperature, in LRS. Conductive filaments were thought to form inside the AlO x film and the Cu-doped AlO x film, causing resistive switching. The resistive memory device using the AlO x film had unstable switching behaviors during cyclic testing, whereas the device using the Cu-doped AlO x film demonstrated stable resistance switching during 100 cycles of testing. The presence of the Cu ingredient in the AlO x film is likely to facilitate the formation and rupture of conductive filaments and induced stable resistance switching. - Highlights: • AlO x layers are formed by plasma oxidation for resistance memory device (RRAM). • Al/AlO x /Al and Al/AlO x -CuO x /Al-Cu exhibit unipolar resistance switching. • Cu doping assists formation of the filaments of mixed Al and Cu in AlO x . • Cu doping improves endurance and retention of the AlO x -based RRAM

  9. Benefits for Military Veterans with ALS

    Science.gov (United States)

    ... Chapters Certified Centers and Clinics Support Groups About ALS About Us Our Research In Your Community Advocate ... Veterans Resources for Military Veterans, Families & Survivors The ALS Association is working everyday to support people with ...

  10. Das Wörterbuch als Grammatik?

    OpenAIRE

    Wellmann, Hans

    1996-01-01

    Das Wörterbuch als Grammatik? - In: Das Lernerwörterbuch Deutsch als Fremdsprache in der Diskussion / hrsg. von Irmhild Barz ... - Heidelberg : Winter, 1996. - S. 219-241. - (Sprache - Literatur und Geschichte ; 12)

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

    Directory of Open Access Journals (Sweden)

    Duski Ibrahim

    2015-10-01

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

  12. 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.

  13. Aspectos clínicos y niveles de plomo en niños expuestos de manera paraocupacional en el proceso de reciclaje de baterías de automóviles en las localidades de Soacha y Bogotá, D.C.

    Directory of Open Access Journals (Sweden)

    Jairo Echeverry

    2008-03-01

    Conclusión. Este trabajo descriptivo aporta un claro signo de alarma ante las autoridades sanitarias y de gobierno, a fin de tomar medidas tendientes a disminuir la exposición ocupacional, o paraocupacional de los niños, al reciclaje de baterías, mediante un programa de prevención y tamización en municipios y localidades del área metropolitana de Bogotá y Soacha.

  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. Laser alloyed Al-Ni-Fe coatings

    CSIR Research Space (South Africa)

    Pityana, SL

    2008-10-01

    Full Text Available The aim of this work was to produce crack-free thin surface layers consisting of binary (Al-Ni, Al-Fe) and ternary (Al-Ni-Fe) intermetallic phases by means of a high power laser beam. The laser surface alloying was carried out by melting Fe and Ni...

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  17. Opportunity's 'Rub al Khali' Panorama

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for Opportunity's 'Rub al Khali' Panorama (QTVR) This panoramic image, dubbed 'Rub al Khali,' was acquired by NASA's Mars Exploration Rover Opportunity on the plains of Meridiani during the period from the rover's 456th to 464th sols on Mars (May 6 to May 14, 2005). Opportunity was about 2 kilometers (1.2 miles) south of 'Endurance Crater' at a place known informally as 'Purgatory Dune.' The rover was stuck in the dune's deep fine sand for more than a month. 'Rub al Khali' (Arabic translation: 'the empty quarter') was chosen as the name for this panorama because it is the name of a similarly barren, desolate part of the Saudi Arabian desert on Earth. The view spans 360 degrees. It consists of images obtained in 97 individual pointings of the panoramic camera. The camera took images with five camera filters at each pointing. This 22,780-by-6,000-pixel mosaic is an approximately true-color rendering generated using the images acquired through filters admitting light wavelengths of 750, 530, and 480 nanometers. Lighting varied during the nine sols it took to acquire this panorama, resulting in some small image seams within the mosaic. These seams have been smoothed in sky parts of the mosaic to better simulate the vista that a person would see if able to view it all at the same time on Mars. Opportunity's tracks leading back to the north (center of the panorama) are a reminder of the rover's long trek from Endurance Crater. The deep ruts dug by Opportunity's wheels as it became stuck in the sand appear in the foreground. The crest and trough of the last ripple the rover crossed before getting stuck is visible in the center. These wind-formed sand features are only about 10 to 15 centimeters (4 to 6 inches) tall. The crest of the actual ripple where the rover got stuck can be seen just to the right of center. The tracks and a few other places on and near ripple crests can be seen in this color image to

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

    International Nuclear Information System (INIS)

    Balanetskyy, S.; Grushko, B.

    2008-01-01

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

  19. Customer relationship management

    OpenAIRE

    Gudeliūnas, Mindaugas

    2016-01-01

    My name is Mindaugas Gudeliūnas. My bachelors thesis topic is "Customer Relationship Management". The main goal of my work was to investigate customers relationship management and to create modern system, which is fast, easy to use and made for small business. Customer relationship management is really beneficial for a lot of companies. It can make your relationships with a customer more reliable and loyal, it can automate a lot of processes, which are related to customer management, human re...

  20. Cryogenic properties of a P/M Ni/sub 3/Al-B alloy

    International Nuclear Information System (INIS)

    Chang, K.M.; Huang, S.C.; Taub, A.I.; Chang, G.M.; Morris, J.W. Jr.

    1987-01-01

    Polycrystalline Ni/sub 3/Al-based intermetallic alloys have overcome their room temperature brittleness problem with a small amount or boron addition. Because of their unique strength-temperature relationship and good oxidation resistance at high temperatures, research efforts have been concentrated extensively on structural applications at elevated temperatures. In this paper the authors show that ductile Ni/sub 3/Al-B alloys also exhibit remarkable mechanical properties at cryogenic temperatures

  1. Challenging the Réal Plan: An Examination of Human Rights and Socioeconomic Marginalization in Brazil

    OpenAIRE

    Alyssa Batchelor; Margaret Tseng

    2015-01-01

    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...

  2. How do relationships begin?

    NARCIS (Netherlands)

    Holmen, Elsebeth; Roos, Kaspar; Kallevag, Magne; von Raesfeld Meijer, Ariane M.; de Boer, L.; Pedersen, Ann-Charlott

    2005-01-01

    In this paper we address the issue ‘How do relationships begin?’ Based on a review of work within theIMP Approach on stage and state models of relationship evolution, we conclude that very littleattention has been paid to beginnings of relationships. We discuss why this might be so, and why theissue

  3. Intimate Relationships and Psychopathology

    Science.gov (United States)

    Whisman, Mark A.; Baucom, Donald H.

    2012-01-01

    Relationship functioning and individual mental health and well-being are strongly associated with one another. In this article, we first review the cross-sectional and longitudinal associations between relationship discord and various types of psychopathology, We then review findings suggesting that relationship discord is associated with poorer…

  4. Instandhaltungsmanagement als Gestaltungsfeld Ganzheitlicher Produktionssysteme

    Science.gov (United States)

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

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

  5. 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.

  6. Species delimitation and interspecific relationships of the genus Orychophragmus (Brassicaceae inferred from whole chloroplast genomes

    Directory of Open Access Journals (Sweden)

    Huan Hu

    2016-12-01

    Full Text Available IntroductionIt is rather difficult to delimit recently diverged species and construct their interspecific relationships because of insufficient informative variations of sampled DNA fragments (Schluter, 2000; Arnold, 2006. The genome-scale sequence variations were found to increase the phylogenetic resolutions of both high- and low-taxonomic groups (e.g., Yoder et al., 2013; Lamichhaney et al., 2015. It is still expensive to collect nuclear genome variations between species for most none-model genera without the reference genome. However, chloroplast genomes (plastome are relatively easy to be assembled to examine interspecific relationships for phylogenetic analyses, especially in addressing unresolved relationship at low taxonomic levels (Wu et al., 2010; Nock et al., 2011; Yang et al., 2013; Huang et al., 2014; Carbonell-Caballero et al., 2015. Plastomes are haploid with maternal inheritance in most angiosperms (Corriveau and Coleman, 1988; Zhang and Liu, 2003; Hagemann, 2004 and are highly conservative in gene order and genome structure with rare recombinations (Jansen et al., 2007; Moore et al., 2010. In this study, we aimed to examine species delimitation and interspecific relationships in Orychophragmus through assembling chloroplast genomes of multiple individuals of tentatively delimited species (Hu et al., 2015a. Orychophragmus is a small genus in the mustard family (Brassicaceae, Cruciferae distributed in northern, central, and southeastern China (Zhou et al., 2001. Its plants have been widely cultivated as ornamentals, vegetables, or source of seed oil (Sun et al., 2011. Despite controversial species delimitations in the genus (Zhou et al., 1987; Tan et al., 1998; Wu and Zhao, 2003; Al-Shehbaz and Yang, 2000; Zhou et al., 2001; Sun et al., 2012, our recent study based on nuclear (nr ITS sequence variations suggested the recognition of seven species (Hu et al., 2015a. Orychophragmus is sister to Sinalliaria, which is a genus endemic

  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. 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.

  9. 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.

  10. Electrical Impedance Myography (EIM) in the Evaluation of the Tongue Musculature in Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    Shellikeri, Sanjana; Yunusova, Yana; Green, Jordan R.; Pattee, Gary L.; Berry, James D.; Rutkove, Seward B.; Zinman, Lorne

    2015-01-01

    Introduction Electrical impedance myography (EIM) quantifies muscle health and is used as a biomarker of muscle abnormalities in neurogenic and myopathic diseases. EIM has yet to be evaluated in the tongue musculature in people with amyotrophic lateral sclerosis (ALS), who often show clinical bulbar signs. Methods The lingual musculature of 19 subjects with motor neuron disease and 21 of normal participants were assessed using EIM, strength and endurance testing, and clinical observation. Results Tongue musculature in the ALS group was characterized by significantly smaller phase (Ph) and larger resistance (R) when compared to the healthy cohort. Ph and tongue endurance were correlated in the ALS group. Discussion EIM of tongue musculature could distinguish people with ALS from healthy controls. The demonstrated relationship between tongue function and Ph supports further testing of EIM of the tongue as a potential biomarker in ALS. PMID:25580728

  11. Jihadism and Suicide Attacks : al-Qaeda, al-Sahab and the Meanings of Martyrdom

    NARCIS (Netherlands)

    Nanninga, Pieter

    2014-01-01

    Dit proefschrift onderzoekt waarom zelfmoordaanslagen zo’n belangrijke rol spelen binnen de jihadistische beweging, en in het bijzonder binnen het al-Qaeda van Osama bin Laden en Ayman al-Zawahiri. Dit doet het op basis van de martelarenvideo’s van al-Qaeda’s mediagroep al-Sahab: vrij professionele

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

    Science.gov (United States)

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

    2016-06-01

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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    Science.gov (United States)

    Park, Su-Yeon; Kim, Sung-Min; Sung, Jung-Joon; Lee, Kyung-Min; Park, Kyung-Seok; Kim, Sang-Yun; Nam, Hyun-woo; Lee, Kwang-Woo

    2013-01-01

    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. 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 (SpO2hypoxia, 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. 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.

  15. 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 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.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.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.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.

  16. Mechanochemically synthesized Fe{sub 3}Al-Al{sub 2}O{sub 3} nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Khodaei, M. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Enayati, M.H. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: ena78@cc.iut.ac.ir; Karimzadeh, F. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2009-01-07

    Fe{sub 3}Al-Al{sub 2}O{sub 3} nanocomposite powder was successfully synthesized by mechanochemical route starting from Fe{sub 2}O{sub 3} and Al powder mixture. The resulting nanocomposite powder was consolidated at 1400 deg. C for 1 h. The phase transformation and microstructural characterization during mechanochemical reaction and sintering were investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results showed that during ball milling the Fe{sub 2}O{sub 3}-Al combustion reaction directly produces the Fe{sub 3}Al-Al{sub 2}O{sub 3} nanocomposite. The consolidated Fe{sub 3}Al-Al{sub 2}O{sub 3} part had an ultrafine uniform structure without 'core-rim' feature consisting of an interconnected network of Fe{sub 3}Al and Al{sub 2}O{sub 3} phases.

  17. A reply to Iversen et al.'s comment “Monitoring of animal abundance by environmental DNA - An increasingly obscure perspective”

    Science.gov (United States)

    Klymus, Katy E.; Richter, Catherine A.; Chapman, Duane C.; Paukert, Craig

    2015-01-01

    We appreciate the conversation put forward by Iversen et al. (2015) in their response to our article “Quantification of eDNA shedding rates from invasive bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix” in the 2015 environmental DNA special issue of Biological Conservation.We agree with Iversen et al.'s concern about overly optimistic conclusions that could be drawn from the current eDNA literature. One hope for eDNA technology is that it can be used in estimating abundance or population density. Evidence suggests that eDNA measurements correlate with total biomass (Takahara et al., 2012) rather than abundance. We demonstrate a similar relationship between biomass and eDNA shedding rates. Nevertheless, without field testing of these methods and specific survey protocols, we cannot make strong conclusions regarding the technique's field applicability. In our manuscript, we attempted to point out areas in which more research is needed.

  18. Impact of Al content on InAs/AlSb/Al(xGa(1−xSb tunnelling diode

    Directory of Open Access Journals (Sweden)

    Yuping Zeng

    2017-06-01

    Full Text Available A method to engineer the peak-to-valley ratio (PVR by design of the epitaxial layers is presented. The impact of Al content on PVR of InAs/AlSb/Al(xGa(1−xSb tunnelling diode is studied. A simplified analytical model is used to explain the PVRs dependence on Al content. It was found that PVR reaches its maximum when Al content x is zero with a quantised InAs layer. The peak positions appeared in the negative differential region are effectively controlled by the applied gate bias. A PVR ratio as high as 7.1 was achieved, which is beneficial for a wide range of circuit applications. Adjusting Al content provides a new way to engineer the PVR as opposed to the conventional way of being optimised by varying barrier thicknesses or doping levels.

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

    Directory of Open Access Journals (Sweden)

    Raushani Azza

    2018-03-01

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

  20. Aproximaciones cientificas al mestizo mexicano

    Directory of Open Access Journals (Sweden)

    Carlos Lopez-Beltran

    2013-06-01

    Full Text Available La categoría colonial del mestizo fue un recurso ideológico, formador de la identidad nacional en la posrevolución mexicana. El eje indio-mestizo sirvió para organizar las interacciones étnicas y las políticas del estado. Médicos y antropólogos reforzaron esta taxonomía dual en estudios de poblaciones humanas, produciendo con marcadores biomédicos y descripciones diferenciadas del indio y del mestizo. Las descripciones genómicas han contribuido tanto a la construcción de una noción cientificista del mestizo arraigada en porcentajes de ancestría india, europea y africana, como al surgimiento de dos objetos tecnocientíficos que llamamos el mestizo molecular y el mestizo bioinformático. Aquí describimos las interacciones entre las encarnaciones ideológicas y científicas del mestizo.

  1. Comentario al libro: ACADEMIA MUTISIANA

    Directory of Open Access Journals (Sweden)

    Efraím Otero Ruiz

    2012-04-01

    Full Text Available Por tercera vez en un quinquenio ocupo este podio para ocuparme de uno de los libros del grupo de inmunogenética (o de anti-inmunohistoria, diría yo de la Universidad Javeriana, esta vez enriquecido con la presencia del P. Ortiz Valdivieso, orquídeologo y mutisiólogo y del Dr. Uribe Angel notable historiador educativo, y presentado admirablemente por el P. Durán Casas, Vicerrector Académico de la Universidad Javeriana. En el prólogo, citando desde Sarton y Ziman en los 70s. hasta Mauro Torres en el 2011 afirmo que, aunque suene extraño, parece como si las Academias florecieran entre las guerras. Tal sucedió con la de Platón, “la máxima institución de enseñanza superior surgida en el mundo”, -al decir de Sartonenmarcada desde las guerras del Peloponeso, hasta el final de la dominación espartana de Atenas en el siglo IV antes de Cristo. Según dichos autores, las Academias han simbolizado una manera de continuar la vida espiritual entre uno y otro conflicto.

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  3. 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.

  4. Job satisfaction among primary health care physicians and nurses in Al-madinah Al-munawwara.

    Science.gov (United States)

    Al Juhani, Abdullah M; Kishk, Nahla A

    2006-01-01

    Job satisfaction is the affective orientation that an employee has towards his work. Greater physician satisfaction is associated with greater patient adherence and satisfaction. Nurses' job satisfaction, have great impact on the organizational success. Knowing parts of job dissatisfaction among physicians and nurses is important in forming strategies for retaining them in primary health care (PHC) centers. Therefore, this study aimed at assessing the level of job satisfaction among PHC physicians and nurses in Al- Madina Al- Munawwara. Also, to explore the relationship of their personal and job characteristics with job satisfaction. A descriptive cross- sectional epidemiological approach was adopted. A self completion questionnaire was distributed to physicians and nurses at PHC centers. A multi-dimensional job scale adopted by Traynor and Wade (1993) was modified and used. The studied sample included 445 health care providers, 23.6% were physicians and 76.4% were nurses. Job dissatisfaction was highly encountered where 67.1% of the nurses & 52.4% of physicians were dissatisfied. Professional opportunities, patient care and financial reward were the most frequently encountered domains with which physicians were dissatisfied. The dissatisfying domains for majority of nurses were professional opportunities, workload and appreciation reward. Exploring the relation between demographic and job characteristics with job satisfaction revealed that older, male, non-Saudi, specialists physicians had insignificantly higher mean score of job satisfaction than their counterparts. While older, female, non-Saudi, senior nurses had significantly higher mean score than their counterparts. It is highly recommended to reduce workload for nurses and provision of better opportunities promotional for PHC physicians and nurses.

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  6. 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....

  7. GLOBAL RELATIONSHIP MANAGEMENT

    OpenAIRE

    Er Kirtesh Jailia; Mrs.Manisha jailia; Er.Priyanka Jailia

    2010-01-01

    In this paper we are going to discuss about the concept of Global relationship management. This is an important concept because now a day the whole business community is moving globally, means the geographical boundaries are of no more concern for the business communities. The global thinking of the business communities leads to the global relationship hence it is important for them to effectively manage such global relationship so that they can achieve what they want. The main concern is ove...

  8. 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

  9. Influence of modifier on base Al and Si on structure and elongation Al-7%Si alloy

    Directory of Open Access Journals (Sweden)

    T. Lipiński

    2008-08-01

    Full Text Available A homogenous modifier with Al and Si obtained by the rapid solidification at a cooling rate equal to v=200 K/s was applied to the modification of the Al-7%Si alloy. The different modifiers were obtained by means of the Al-Si alloys. The components Al, Al-7%Si and Al-12%Si were put into crucible containing the liquid Al-7%Si alloy and kept for one minute to obtain a new homogenous alloy which after break-up was homogenous modifier. Both, effect of cooling rate applied to obtain modifier and weight in weight modifier concentration in the melt on structure and elongations of Al-7%Si alloy are determined. A structural, and elongations resulting from the Al-7%Si alloy treatment by modifiers are studied in details.

  10. Genetics of Familial and Sporadic ALS

    Science.gov (United States)

    2018-03-27

    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. Decoding ALS: From Genes to Mechanism

    Science.gov (United States)

    Taylor, J. Paul; Brown, Robert H.; Cleveland, Don W.

    2017-01-01

    Preface Amyotrophic lateral sclerosis (ALS) is a progressive and uniformly fatal neurodegenerative disease. A plethora of genetic factors underlying ALS have now been identified that drive motor neuron degeneration, increase susceptibility to the disease, or influence the rate of progression. Emerging themes include dysfunction in RNA metabolism and protein homeostasis, with specific defects in nucleocytoplasmic trafficking, induction of endoplasmic reticulum stress, and impaired dynamics of ribonucleoprotein bodies such as RNA granules that assemble through the process of liquid-liquid phase separation. Extraordinary recent progress in understanding the biology of ALS provides new grounds for optimism that meaningful therapies for ALS will be identified. PMID:27830784

  12. Referral bias in ALS epidemiological studies.

    Science.gov (United States)

    Logroscino, Giancarlo; Marin, Benoit; Piccininni, Marco; Arcuti, Simona; Chiò, Adriano; Hardiman, Orla; Rooney, James; Zoccolella, Stefano; Couratier, Philippe; Preux, Pierre-Marie; Beghi, Ettore

    2018-01-01

    Despite concerns about the representativeness of patients from ALS tertiary centers as compared to the ALS general population, the extent of referral bias in clinical studies remains largely unknown. Using data from EURALS consortium we aimed to assess nature, extent and impact of referral bias. Four European ALS population-based registries located in Ireland, Piedmont, Puglia, Italy, and Limousin, France, covering 50 million person-years, participated. Demographic and clinic characteristics of ALS patients diagnosed in tertiary referral centers were contrasted with the whole ALS populations enrolled in registries in the same geographical areas. Patients referred to ALS centers were younger (with difference ranging from 1.1 years to 2.4 years), less likely to present a bulbar onset, with a higher proportion of familial antecedents and a longer survival (ranging from 11% to 15%) when compared to the entire ALS population in the same geographic area. A trend for referral bias is present in cohorts drawn from ALS referral centers. The magnitude of the possible referral bias in a particular tertiary center can be estimated through a comparison with ALS patients drawn from registry in the same geographic area. Studies based on clinical cohorts should be cautiously interpreted. The presence of a registry in the same area may improve the complete ascertainment in the referral center.

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

    Directory of Open Access Journals (Sweden)

    Benny Afwadzi

    2017-01-01

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

  14. Tadris Al Mufradat Li Tathbiq Maharah Al Kalam Fi Madrasah Al Muallimin Al Islamiyyah Li Mahad Bait Al Arqam Balong Jember

    Directory of Open Access Journals (Sweden)

    Muhammad Ardy Zaini

    2017-06-01

    Full Text Available There are four  skills in teaching Arabic. Ie listening, speaking, reading, and writing. Among these four, speaking considered one of the most important objectives of learning foreign language. In order to speak properly, one must know the vocabulary and apply it in a sentence. The aims of this research is to describe the teaching of vocabulary to apply the speaking skill in the school of Islamic teachers in the Institute of Bait al Arqom Balong Jember. This study used qualitative approach. The data collection was taken trough observation, personal interview, history and documentation. The teaching of vocabulary to apply the speaking skill at the Islamic Teachers' School at the Institute of Bait Al Arqam Balong Jember has gone well in terms of planning (general objectives and specific objectives, implementation (materials, use of the teaching method and teaching aids, and evaluation (assessment and evaluation. This teaching is to apply the speaking skill in terms of conversation or dialogue and lecture.

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

    Directory of Open Access Journals (Sweden)

    S. Kores

    2012-04-01

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

  16. Processing and Mechanical Properties of Directionally Solidified NiAl/NiAlTa Alloys

    Science.gov (United States)

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

    1994-01-01

    Promising creep strengths were found for a directionally solidified NiAl-NiAlTa alloy when compared to other NiAl based intermetallics. The directionally solidified alloy had an off-eutectic composition that resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The room temperature toughness of the two phase alloy was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa. Alloying additions that may improve the room temperature toughness by producing multiphase alloys are discussed.

  17. Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rong [Chongqing Jiaotong Univ., Chongqing (China). College of Materials Science and Engineering; Tang, Bin [Chongqing City Management College, Chongqing (China). Inst. of Finance and Trade; Gao, Tao [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics

    2017-09-01

    The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C{sub V} and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.

  18. Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles

    International Nuclear Information System (INIS)

    Yang, Rong; Tang, Bin; Gao, Tao

    2017-01-01

    The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C V and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.

  19. Respuesta inmune adaptativa al rotavirus

    Directory of Open Access Journals (Sweden)

    Manuel A. Franco

    2004-03-01

    Full Text Available

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

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

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

  20. Revisiting Okun's Relationship

    NARCIS (Netherlands)

    Dixon, R.; Lim, G.C.; van Ours, Jan

    2016-01-01

    Our paper revisits Okun's relationship between observed unemployment rates and output gaps. We include in the relationship the effect of labour market institutions as well as age and gender effects. Our empirical analysis is based on 20 OECD countries over the period 1985-2013. We find that the

  1. Revisiting the Okun relationship

    NARCIS (Netherlands)

    Dixon, R. (Robert); Lim, G.C.; J.C. van Ours (Jan)

    2017-01-01

    textabstractOur article revisits the Okun relationship between observed unemployment rates and output gaps. We include in the relationship the effect of labour market institutions as well as age and gender effects. Our empirical analysis is based on 20 OECD countries over the period 1985–2013. We

  2. Transformation through relationships.

    Science.gov (United States)

    Lewis-Hunstiger, Marty

    2014-01-01

    Relationship with self, with colleagues, and with patients and their families, along with an emerging professional relationship with community, are described in articles by nurse educators, organizational leaders, and an entrepreneur from diverse locations and settings all devoted to preparing, empowering, and sustaining nurses and those for whom we care.

  3. Kritik al-Ghazali terhadap Kekekalan Alam

    Directory of Open Access Journals (Sweden)

    Sahidi Mustafa

    2015-09-01

    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.

  4. Sexuality and embodiment in relationships

    OpenAIRE

    Barker, Meg; Langdridge, Darren

    2013-01-01

    In general what sets 'a relationship' (of the kind this book, and relationship therapy more broadly, focuses on) apart from other kinds of relationships (friendships, collegiate relationships, family relationships and so forth) is often taken to be the fact that it is 'sexual'. The phrases 'romantic relationship', 'intimate relationship' and 'sexual relationship' tend to be used interchangeably. Indeed, in popular magazines, television programmes and self-help books, the quantity and quality ...

  5. Effect of Al2O3sf addition on the friction and wear properties of (SiCp+Al2O3sf)/Al2024 composites fabricated by pressure infiltration

    Science.gov (United States)

    Xu, Hui; Zhang, Gong-zhen; Cui, Wei; Ren, Shu-bin; Wang, Qian-jin; Qu, Xuan-hui

    2018-03-01

    Aluminum (Al) 2024 matrix composites reinforced with alumina short fibers (Al2O3sf) and silicon carbide particles (SiCp) as wear-resistant materials were prepared by pressure infiltration in this study. Further, the effect of Al2O3sf on the friction and wear properties of the as-synthesized composites was systematically investigated, and the relationship between volume fraction and wear mechanism was discussed. The results showed that the addition of Al2O3sf, characterized by the ratio of Al2O3sf to SiCp, significantly affected the properties of the composites and resulted in changes in wear mechanisms. When the volume ratio of Al2O3sf to SiCp was increased from 0 to 1, the rate of wear mass loss ( K m) and coefficients of friction (COFs) of the composites decreased, and the wear mechanisms were abrasive wear and furrow wear. When the volume ratio was increased from 1 to 3, the COF decreased continuously; however, the K m increased rapidly and the wear mechanism became adhesive wear.

  6. Organizational Relationship Termination Competence

    DEFF Research Database (Denmark)

    Ritter, Thomas; Geersbro, Jens

    2011-01-01

    Most firms are involved in a number of customer relationships that drain the firm's resources. However, many firms are hesitant to address this problem. This paper investigates customer relationship termination at the organizational level. We develop and analyze the organizational dimensions...... that a firm's percentage of unwanted customers decreases significantly as acceptance of termination increases, if the firm's definition of unwanted customers is well understood, and if a firm has clear termination routines. In addition, general focus on profitability and external constraints on relationship...... 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...

  7. 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.

  8. The effect of microstructures on mechanical behaviors of Ti2AlNb intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liming; Yao, Mei; Zou, Dunxu; Zhu, Dong; Cai, Qigong (Harbin Institute of Technology, (China) Central Iron and Steel Research Institute, Beijing, (China))

    1992-03-01

    Ti2AlNb intermetallics are presently heat-treated and subjected to compressive loading at various temperatures, in order to ascertain microstructure-mechanical behavior relationships. Heat-treated and oil-quenched samples exhibit beta phase; the 'O' phase transformation was restrained by quenching. The O phase increased with rising heat-treatment temperature. 10 refs.

  9. Ideal shear strength and deformation behaviours of L10 TiAl from ...

    Indian Academy of Sciences (India)

    The stress–strain relationships for four different shear processes of L1 0 TiAl have been investigated from first-principles calculations, and the peak shear stresses in ... Key Laboratory of New Electric Functional Materials of Guangxi Colleges and Universities, Guangxi Teachers Education University, Nanning 530023, China ...

  10. Ideal shear strength and deformation behaviours of L10 TiAl from ...

    Indian Academy of Sciences (India)

    strain relationships for four different shear processes of L10 TiAl have been investigated .... aThis work; bRef. [27]. Figure 3. The structural unit cell and the bond length vs. true strain for (a) 〈1¯10]{111},. (b) 〈0¯11]{111}), (c) 〈11¯2]{111} and (d) ...

  11. TEM study of continuous precipitation in Mg-9 Wt%Al-l Wt%Zn alloy

    NARCIS (Netherlands)

    Celotto, S

    2000-01-01

    The development of continuous precipitate morphology in heat-treated Mg-9 wt%Al-1 wt%Zn alloy (AZ91) for a range of ageing temperatures is investigated in detail using TEM. The matrix/precipitate orientation relationships (ORs), sizes, shapes and the number of precipitates per unit volume (N-V) are

  12. Elk, beaver, and the persistence of willows in national parks: comment on Singer et al. (1998).

    Science.gov (United States)

    Keigley, R.B.

    2000-01-01

    Singer et al. (1998) propose that the decline in populations of beaver (Castor canadensis) in Yellowstone National Park (YNP) has caused willow to be more vulnerable to browsing by clk (Alces alces). I do not believe that their scenario correctly characterizes the relationship between elk and willow in YNP

  13. Activation energy of psuedobinary alloy of Al-Bi-Se mixed systems ...

    African Journals Online (AJOL)

    The current-voltage characteristics also show linear relationship which satisfies the Arrhenius relation δ = δoexp (-ξ/kT) typical of semiconductor materials. The activation energy of the sample was found to be 0.012eV. This indicates that the Al-Bi-Se mixed systems posses semiconductor properties and can therefore, ...

  14. Interrelation of work function and surface stability : The case of BaAl4

    NARCIS (Netherlands)

    Uijttewaal, MA; de Wijs, GA; de Groot, RA; Coehoorn, R; van Elsbergen, [No Value; Weijtens, CHL

    2005-01-01

    The relationship between the work function (Phi) and the surface stability of compounds is, to our knowledge, unknown but very important for applications such as organic light-emitting diodes. This relation is studied using first-principles calculations on various surfaces of BaAl4. The most stable

  15. THE MEANING OF AL-QALB AND DISCLOSURE IN AL-QUR’AN

    Directory of Open Access Journals (Sweden)

    Agustiar Agustiar

    2017-01-01

    Full Text Available Human being equipped by God Almighty with a variety of gifts which enable them to carry a burden of duties. The gifts are power of the body, vitality and power al-qalb. Islam has made clear necessity of a proper functioning of al-qalb to think in order to develop knowledge. It will help people to carry caliphate duties on earth properly, under the guidance of al-Qur’an and al-Sunnah. One way to enhance thinking of al-qalb required by Islam is dzikir, therefore, someone will find peace of mind and feel close to God. Feeling close to God, a person’s soul will be controlled. Conversely, if a person is not functioning qalb for dzikir, so he will experience drought soul. In al-Qur’an, al-qalb may have some meanings; it refers to the context of verse that contains in it. Moreover, to present the meaning of al-qalb is not always disclosure with the word of al-qalb, but also often disclosure by using the word of al-fuad, al-lub, al-nafs and al-sadr

  16. FEM modeling on the compaction of Fe and Al composite powders

    Directory of Open Access Journals (Sweden)

    Han P.

    2015-01-01

    Full Text Available The compaction process of Fe and Al composite powders subjected to single action die compaction was numerically modeled by FEM method. The relationship between the overall relative density and compaction pressure of the compacts with various Al contents was firstly identified, and the influences of Al content on the local relative density, stress, and their distributions were studied. Then the compaction pressure effects on the above properties with fixed Al content were discussed. Furthermore, detailed flow behaviors of the composite powders during compaction and the relationship between the compaction pressure and the ejection force/spring back of the compact were analyzed. The results show that: (1 With each compaction pressure, higher relative density can be realized with the increase of Al content and the relative density distribution tends to be uniform; (2 When the Al content is fixed, higher compaction pressure can lead to composite compact with higher relative density, and the equivalent Von Mises stress in the central part of the compact increases gradually; (3 Convective flow occurs at the top and bottom parts of the compact close to the die wall, each indicates a different flow behavior; (4 The larger the compaction pressure for each case, the higher the residual elasticity, and the larger the ejection force needed.

  17. Simulations of the premelting of Al(110)

    DEFF Research Database (Denmark)

    Stoltze, Per

    1990-01-01

    The premelting of Al(110) is studied by molecular dynamics simulations using the potential for Al derived from effective medium theory. We find a progressive disordering of the surface region as the bulk melting point is approached. This disorder is mediated by the formation of adatom–vacancy pairs...

  18. Miércoles al cine

    OpenAIRE

    Aguado Franco, Juan Carlos

    2014-01-01

    Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Se analiza un caso concreto de demanda ante una iniciativa empresarial: los miércoles al cine. Fundamentos del Análisis Económico

  19. Harnanti et al., Afr., J. Infect. Dis.

    African Journals Online (AJOL)

    USER

    2017-10-23

    Oct 23, 2017 ... 86 cases (5.4%), chancroid in 2 cases (1.4%), while bacterial vaginosis, gonorrhea urethritis, molluscum contagiosum and. Bartholin's cyst each was 1 case (0.7%).The results were different from a previous study done by Tzeng et al. in 2013which showed that the highest STI was Chlamydia (Tzeng et al., ...

  20. AMARI LDGE et al..xps

    African Journals Online (AJOL)

    HP Pro 2000

    elongated necrotic lesions surrounded by chlorosis, suggests a possible involvement of the pathogen phytotoxic-compound (Molina et al., 1989, Upadhyay et al., 1990). Some of these toxins, already identified, could constitute an alternative technique for a rapid screening of resistant genotypes in banana allowing an early.

  1. 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…

  2. Presymptomatic ALS genetic counseling and testing

    Science.gov (United States)

    Stanislaw, Christine; Reyes, Eliana; Hussain, Sumaira; Cooley, Anne; Fernandez, Maria Catalina; Dauphin, Danielle D.; Michon, Sara-Claude; Andersen, Peter M.; Wuu, Joanne

    2016-01-01

    Remarkable advances in our understanding of the genetic contributions to amyotrophic lateral sclerosis (ALS) have sparked discussion and debate about whether clinical genetic testing should routinely be offered to patients with ALS. A related, but distinct, question is whether presymptomatic genetic testing should be offered to family members who may be at risk for developing ALS. Existing guidelines for presymptomatic counseling and testing are mostly based on small number of individuals, clinical judgment, and experience from other neurodegenerative disorders. Over the course of the last 8 years, we have provided testing and 317 genetic counseling sessions (including predecision, pretest, posttest, and ad hoc counseling) to 161 first-degree family members participating in the Pre-Symptomatic Familial ALS Study (Pre-fALS), as well as testing and 75 posttest counseling sessions to 63 individuals with familial ALS. Based on this experience, and the real-world challenges we have had to overcome in the process, we recommend an updated set of guidelines for providing presymptomatic genetic counseling and testing to people at high genetic risk for developing ALS. These recommendations are especially timely and relevant given the growing interest in studying presymptomatic ALS. PMID:27194384

  3. 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

  4. 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.

  5. 76 FR 35938 - The Designation of Othman al-Ghamdi Also Known as Al Umairah al-Ghamdi, Also Known as Uthman al...

    Science.gov (United States)

    2011-06-20

    ... the Order who might have a constitutional presence in the United States would render ineffectual the... determination who might have a constitutional presence in the United States, because to do so would render... DEPARTMENT OF STATE [Public Notice 7505] The Designation of Othman al-Ghamdi Also Known as Al...

  6. 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

  7. The Y-Cu-Al system

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  8. Characterization of Nb/AlOx-Al/Nb Josephson junctions by anodization profiles

    International Nuclear Information System (INIS)

    Imamura, T.; Hasuo, S.

    1989-01-01

    The thin tunneling barrier in a Nb/AlO x -Al/Nb Josephson junction was characterized by anodization profiles. Our studies focused on Nb/AlO x and Al/Nb interfaces in Nb/AlO x -Al/Nb junctions made by varying certain process parameters. The interface quality was checked by the anodization profiles and was greatly affected by film thickness, layer sequence, annealing treatment, and the existence of a thin oxide. By comparing the profiles with the junction characteristics measured at 4.2 K, we confirmed that the interface sharpness in the profiles is related to the junction quality. The anodization profile is a useful tool to diagnose the tunneling barrier interfaces in Nb/AlO x -Al/Nb Josephson junctions, especially at room temperature during fabrication

  9. Cross-sectional TEM observation of Nb/AlOx-Al/Nb junction structures

    International Nuclear Information System (INIS)

    Imamura, T.; Hasuo, S.

    1991-01-01

    This paper reports on a study of microstructure of Nb/AlO x ---Al/Nb Josephson junctions by cross-sectional transmission electron microscopy (TEM) which yielded much information regarding the unction barrier region. Both thick Nb and several-nm Al form polycrystalline films with columnar structures. Nb is oriented to the (110) plane, and Al is (111). The 200-nm lower Nb has a wavy surface with ∼5 nm smoothness, but its surface is planarized by several-nm Al deposited on it. Thus AlO x with a smoothness under 1 nm can be formed on Al. The upper Nb has a good crystalline structure even just above the AlO x barrier

  10. Cross-sectional transmission electron microscopy observation of Nb/AlOx-Al/Nb Josephson junctions

    International Nuclear Information System (INIS)

    Imamura, T.; Hasuo, S.

    1991-01-01

    A study of microstructure of Nb/AlO x -Al/Nb Josephson junctions by cross-sectional transmission electron microscopy yielded much information regarding the junction barrier region. Both thick Nb and several-nanometer Al form polycrystalline films with columnar structures. Nb is oriented to the (110) plane, and Al is (111). The 200 nm lower Nb has a wavy surface with ∼5 nm smoothness, but its surface is planarized by several nanometers Al deposited on it. Thus AlO x with a smoothness under 1 nm can be formed on Al. The upper Nb has a good crystalline structure even just above the AlO x barrier

  11. 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...

  12. Thermoluminescence properties of AlN ceramics

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  13. HOMENAJE AL DOCTOR JORGE CAVELIER

    Directory of Open Access Journals (Sweden)

    Guillermo Rueda Montaña

    1979-06-01

    ósitos. Jamás concibió nada pequeño, ni en lo material, ni en lo espiritual. Su propio mundo de acción y movimiento, tallado a su imagen y semejanza, no le permitía detenerse en pequeñeces. Cabalgaba
    contra el tiempo, y este no le era suficiente para sus designios. Por eso no podía detenerse en minucias, jamás fue mediocre, ni toleró la mediocridad.

    JORGE CAVELIER pasa al Panteón de los grandes de Colombia, su excepcional condición humana así lo impone, sus valiosos servicios a la Patria así lo demandan, y el profundo rastro que deja de su paso por la vida, así lo decide.

    La CRUZ ROJA COLOMBIANA, que le debe casi todo, ya no será la misma. Será imposible ocupar el inmenso vacío que deja la desaparición del titán. Ocuparemos su sitio, mas no lo reemplazaremos.
    Como las criaturas del bosque milenario, permaneceremos silenciosos y cavilantes ante el majestuoso y doloroso espectáculo de su caída.

    Descanse en Paz.

  14. KONSEP AL-NAFS DALAM KAJIAN TASAWUF AL-GHAZᾹLĪ

    Directory of Open Access Journals (Sweden)

    Paisol Burlian

    2016-03-01

    Full Text Available Abstract: This article will elaborate on al-nafs (soul which is an essential part of human nature. The Sufis divide understanding al-nafs in three senses. First, al-nafs is a substance that distinguishes human qualities with other creatures. Second, al-nafs is the cause of man to be creative and dynamic, through the process of inspiration and contemplation. Therefore, the level of quality of the nafs is different. In the literature of Sufism, the nafs can be transformed from a trend that is closest to the bad action to the level of closeness to the divine tenderness. Third, the nafs is the impulse of anger and lust, and urge all reprehensible nature, and immoral in mind. Sufi Sunni, al-Ghazālī calls nafs as the center of the potential upset, and the base of the despicable nature. Therefore, al-nafs need to be purified so that the properties of self perverted man disappeared. Road purification al-nafs is riyāḍah and mujahadah who constantly so al-nafs is ultimately up to the level of the nafs al-muṭmainnah. Abstrak: Artikel ini akan mengelaborasi tentang al-nafs (jiwa yang merupakan bagian yang penting dari hakikat manusia. Para sufi membagi pengertian al-nafs ini dalam tiga pengertian. Pertama, al-nafs merupakan substansi yang membedakan kualitas manusia dengan makhluk yang lain. Kedua, al-nafs merupakan penyebab manusia menjadi kreatif dan dinamik, melalui proses inspirasi dan tafakur. Karena itu, tingkatan kualitas nafs orang berbeda-beda. Dalam literatur tasawuf, nafs ini dapat ditransformasikan dari kecenderungan yang paling dekat pada tindakan buruk sampai ke tingkat kedekatan pada kelembutan ilahi. Ketiga, nafs ialah dorongan amarah dan syahwat, serta dorongan segala sifat tercela, dan maksiat dalam batin. Seorang sufi Sunni, al-Ghazālī menyebut nafs sebagai pusat potensi marah, dan pangkal dari sifat tercela. Karena itu, al-nafs ini perlu disucikan agar sifat-sifat tercela itu lenyap dari diri manusia. Jalan penyucian al

  15. KONSEP PEMBELAJARAN MENURUT AL-QUR’AN

    Directory of Open Access Journals (Sweden)

    Syukri Syukri

    2011-06-01

    Full Text Available Abstract: All verses Quran are opened to be interpreted in various science contexts, including education. This article focuses on study at reconstructing the instructional concept of Quran. Results of this study indicate that instructional concepts own sturdy bases in al-Qur’an. A lot of verses of Quran give indication of people to learn more about thinking than memorizing. The past occurrence mirrors the instructional dynamics of human learning. The instructors are not only Allah, but also people, bird, and nature. Al-Qur’an always learns human being based on concrete media support even if the items are eschatology and theology. The instructional conception of Quran must not only use term ‘allama-yu‘allimu, but also yuwâri, yatafakkaru containing instructional elements. This reality shows that instructional concepts of Quran put more nuances of concrete-media than abstract-verbal ones.Abstrak:  Semua ayat al-Qur’an terbuka untuk ditafsirkan dalam berbagai konteks keilmuan, termasuk pendidikan. Tulisan ini memfokuskan rekonstruksi konsep pembelajaran al-Qur’an. Hasil kajian ini menunjukkan konsep pembelajaran memiliki dasar kokoh dalam al-Qur’an. Banyak ayat al-Qur’an memberikan indikasi manusia belajar lebih banyak berpikir daripada menghafal. Kejadian masa lalu mencerminkan pembelajaran manusia secara dinamis. Pelaku proses pembelajaran bukan saja Allah, tetapi juga manusia, burung, dan alam. Al-Qur’an membelajarkan manusia berbasis dukungan media konkrit al-Qur’an sekalipun materi eskatologis dan teologis. Konsep pembelajaran al-Qur’an tidak mesti menggunakan istilah ‘allama-yu‘allimu, tetapi juga  yuwâri, yatafakkaru mengandung unsur pembelajaran. Realitas ini menunjukkan, konsep pembelajaran al-Qur’an lebih bernuansa media konkrit daripada abstrak-verbal.

  16. Microstructure and oxidation behaviour of TiAl(Nb)/Ti2AlC ...

    Indian Academy of Sciences (India)

    Ti2AlC phases that showed the carbon that originates from hexane, participated in the reaction to form Ti2AlC during heating. Consolidation of ... Only the presence of γ-TiAl and Ti2AlC was detected and no secondary phases were observed on the base of Nb. ..... [32] Cullity B D 1969 Elements of X-ray diffraction (Reading,.

  17. Dynamic recrystallization in TiAl and Ti3Al intermetallic compounds

    International Nuclear Information System (INIS)

    Salishchev, G.A.; Imayev, R.M.; Imayev, V.M.; Gabdullin, N.K.

    1993-01-01

    The mechanical behaviour and microstructure evolution during hot deformation were investigated in TiAl and Ti 3 Al intermetallic compounds. The features of development of dynamic recrystallization in the both titanium aluminides were established. It is shown that we can use the dynamic recrystallization to obtain the micro- ( anti d∼1 μm) and submicrocrystalline ( anti d∼0,1 μm) structures in the TiAl and Ti 3 Al intermetallic compounds. (orig.)

  18. Al-Qaeda in Iraq (AQI): An Al-Qaeda Affiliate Case Study

    Science.gov (United States)

    2017-10-01

    driving out the infidel invaders; extending what al- Ayman al-Zawahiri, the deputy head of Al-Qaeda (AQ) called the “jihad wave” into Iraq’s...declared in 2009, that large, courageous, and targeted operations are necessary to break the bones of the infidels .”35 After 2010, ISI renewed its...received funding from dedicated Al-Qaeda channels.43 As of 2009, AQI was essentially self- financing , supporting itself through crimes such as extortion

  19. SYAIKH MOHAMED IDRIS AL-MARBAWI: Kontribusinya dalam Fiqh al-Hadîs

    Directory of Open Access Journals (Sweden)

    Faisal bin Ahmad Shah

    2010-06-01

    Full Text Available Sheikh Mohamed Idris al-Marbawi: His Contribution in Fiqh al-Hadîth. Syaikh Mohamed Idris bin Abdul Raof al-Marbawi’s Bahr al-Madhi is a very popular work within the Malaysian community. This work comprizes a translation of 2781 prophetic traditions adapted from Imâm al-Tirmidhî’s al-Jâmi‘, and still continuously reprented and used by large audience in mosques. This study focuses on studying the method of exegesis (syarh of fiqh al-hadîs found in Bahr al-Madhi. As such, the writer analyzes document and makes interviews related to issues relevant to the study. The test for methods used by al-Marbawy in Fiqh al-hadîs is conducted by analyzing the findings through varius interpretaion of al-Hadis. In addition, comparative approach is also used by referring to the works of expert in hadith and identifying how far al-Marbawi’s method is similar or diferent to the former views. This study reveals that al-Marbawi’s commentary on Fiqh al- Hadîs is mainly dominated by issues pertaining to ‘aqîdah (Islamic creed, tafsîr (Qur’anic exegesis, hadîs (Islamic traditions, usûl al-fiqh (Islamic jurisprudence, and history and language. Finally, the writer asserts that due to its divergence scope of discussion, authentivcity andreliability, the Bahr al-Madhi remains the main reference in hadith studies applicable for different disciplines of knowledge.

  20. A framework for assessing and managing large purchaser:minority supplier relationships in supplier diversity initiatives

    OpenAIRE

    Theodorakopoulos, Nicholas; Ram, Monder

    2008-01-01

    Supplier diversity initiatives can function as platforms for EMSs strategic learning (Theodorakopoulos et al., 2005; Theodorakopoulos & Ram, 2006) and the scant research in supplier diversity underscores the importance of relationship factors to the success of supplier diversity/development programmes (e.g. Pearson et al., 1993). However, purchaser-supplier relationship management as a vehicle for enhancing EMSs learning and supply capabilities has not been examined to any length within the c...