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Sample records for dientes incisivos al

  1. Prevalencia de defectos del desarrollo del esmalte en los incisivos permanentes de escolares: un estudio fotográfico en el Sur de Brasil

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    Renata Barbieri Bogo

    2011-01-01

    Full Text Available El objetivo de este estudio fue evaluar la prevalencia y distribución de diferentes tipos de problemas de desarrollo del esmalte (DDE en los incisivos de los escolares de una población de la pequeña ciudad del sur de Brasil. Examinamos a todos los niños y adolescentes que asistieron, del 5 al 8 º grado de educación en las escuelas públicas en la ciudad de Camboriu – SC, cuyas escuelas y cuyos padres aceptaron de forma individual y dieron su consentimiento para su participación. Fueron incluidos en el estudio aquellos que presentaban incisivos con al menos tres cuartas partes de la corona en erupción y en condiciones de ser examinados (sin aparatología ortodontica, fractura, lesión cariosa o restauración extensa, n = 223. Dos evaluadores, previamente capacitados utilizaron los criterios clínicos del “FDI World Dental Federation” para el diagnóstico de DDE, a través de proyección de imágenes de fotografías de los incisivos. Análisis descriptivo y test de Chi-cuadrado. 1728 dientes se clasificaron de acuerdo a la presencia de DDE. La prevalencia de DDE fue del 34,1% para los escolares, siendo que 10,3% de los dientes examinados presentaron algún tipo de DDE. La prevalencia de las diferentes alteraciones en los incisivos examinados fueron: opacidad difusa (6,6%, opacidad demarcada (3,4% e hipoplasia (0,4% y las clasificaciones mas frecuentes fueron la opacidad difusa lineal (3,7% , seguido por opacidad blanca demarcada (3% y opacidad difusa irregular (2,8%. Hubo una asociación estadísticamente significativa (p <0,001 entre la presencia de DDE y la arcada dentaria, siendo los incisivos superiores más afectados. Los incisivos centrales fueron estadísticamente más afectados (p <0,001 que los laterales. Los incisivos inferiores mostraron una prevalencia similar de DDE entre sí. No hubo diferencias estadísticamente significativas en la prevalencia de DDE en función del género y el lado del diente. Se concluye que la

  2. Microdureza del esmalte dental en incisivos centrales permanentes de dos genotipos bovinos

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    Jorge Cabrera A

    2011-04-01

    Full Text Available Objetivo. Evaluar la microdureza del esmalte dental de novillos criollos de origen patagónico y cruza índica criados en ambientes diferentes. Materiales y métodos. Se utilizaron dientes incisivos centrales derechos de novillos adultos: ocho Criollos Patagónicos (GCP y siete Cruzas Índicas (GCI. Para cada diente se definió una transecta central recorriendo el diente desde el borde externo del esmalte hacia la dentina y se midió la dureza en tres profundidades equidistantes: a 30 μ del borde exterior (P1, a 30 μ previos a la conexión amelodentinaria (P3 y P2 equidistante entre P1 y P3. Las mediciones de microdureza se realizaron con un microdurómetro Shimadzu modelo HMV-2 y se expresaron en unidades Vickers. Para el análisis se utilizó un modelo de regresión aleatoria. Se empleó el criterio de información de Akaike para la elección de la estructura de las matrices asociadas a los efectos aleatorios. Para el análisis estadístico se empleó el procedimiento PROC MIXED de SAS, y un nivel de significación del 5%. Resultados. No se detectó falta de paralelismo entre los grupos (p>0.05, con lo cual se ajustaron rectas de igual pendiente en cada grupo. La dureza media del esmalte disminuyó al aumentar la profundidad de la medición para ambos genotipos. Se observó heterogeneidad en la variabilidad de los grupos. Conclusiones. El GCP presentó mayor dureza pero fue el de mayor variabilidad. Se confirma la disminución de la dureza media con el aumento de la profundidad en el esmalte independientemente del genotipo y el ambiente.

  3. Evaluación estética de seis tipos de coronas para dientes primarios

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    Héctor Alejandro Ramírez Peña

    2017-03-01

    Full Text Available Objetivo: Evaluar las preferencias estéticas en relación con el color y la forma de coronas primarias utilizadas para dientes incisivos superiores primarios, mediante la realización de una encuesta a miembros de la Academia Mexicana de Odontología Pediatrica (AMOP. Material y Métodos: Se establecieron seis grupos de estudio con seis coronas diferentes: grupo 1, coronas de zirconia EZ-Pedo; grupo 2, coronas de zirconia NuSmile Zr; grupo 3, coronas estéticas hechas en el consultorio; grupo 4, coronas de fundas de celuloide; grupo 5, coronas estéticas prefabricadas NuSmile signature; y grupo 6, coronas estéticas fenestradas. Se llevaron a cabo encuestas con la finalidad de conocer las preferencias estéticas de estas diferentes coronas, con la finalidad de conocer cuál es la mejor opción para su uso en el consultorio dental. Resultados: Noventa miembros de la AMOP realizaron una encuesta válida, y se determinó que el grupo 4 fue el mejor evaluado, seguido de los grupos 2, 5, 1, 6 y 3. Se identificaron diferencias significativas entre los diferentes grupos. Conclusiones: Las coronas de fundas de celuloide fueron seleccionadas como mejor alternativa de uso en los dientes primarios anteriores, por parte de los miembros de la AMOP; asimismo, se consideró a las coronas de zirconia como una buena opción terapéutica. Es recomendable que se implemente el tratamiento estético en dientes primarios, para realizar un tratamiento integral.

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

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    Chiappe González, Alezandra; Céspedes Porras, Jacqueline

    2006-01-01

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

  5. La hipomineralización incisivo molar y la caries dental

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    Negre Barber, Adela

    2017-01-01

    La formación dental es un proceso largo y complejo que se inicia antes de nacer y termina con la mineralización de los terceros molares al final de la adolescencia. Durante este tiempo, cualquier alteración en el órgano dental puede derivar en un defecto en el desarrollo del esmalte (DDE) observándose al erupcionar el diente.La caries dental y los defectos del esmalte son actualmente los problemas mas frecuentes observados en la dentición temporal y joven permanente. Existen protocolos de pre...

  6. Eficacia de una crema dental para dientes sensibles con citrato de potasio al 5,6% y fluoruro de sodio al 0,3%: ensayo clínico aleatorizado controlado

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    Ramón Morales, Oscar Miguel; Londoño, Walter; González Ortíz, Leydi Yisela; González Patiño, Elizabeth; Blandón, Nadya; García González, Nora Patricia

    2010-01-01

    Introducción: las sales de potasio y el flúor han sido usadas en el tratamiento de la hipersensibilidad dentinaria. El objetivo de este estudio fue determinar la eficacia de una crema dental para dientes sensibles con citrato de potasio al 5,6% y fluoruro de sodio al 0,3%, en la disminución de los síntomas de hipersensibilidad dentinaria. Métodos: se obtuvo una muestra aleatoria de 100 personas, hombres y mujeres, mayores de 18 años procedentes del Valle de Aburrá; que presentaran hipersen...

  7. Prevalencia de los dientes supernumerarios en la población infantil asturiana

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    S. Cueto Blanco; A. Pipa Vallejo; M. González García; C. Pipa Muñiz; I. Álvarez Álvarez

    2013-01-01

    La odontogénesis, que es un proceso extraordinariamente complejo, como el resto del desarrollo embrionario, está expuesta a determinados factores que pueden alterar su normal evolución. En ocasiones podemos observar un número de dientes adicional a la fórmula dental normal y en ese caso se habla de dientes supernumerarios, hiperodoncia o hipergenesia. Los dientes supernumerarios son más frecuentes en varones que en mujeres. Y no es raro que puedan dar lugar a retención de dientes permanentes ...

  8. Dientes supernumerarios: Reporte de un caso clínico

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    Oropeza Murillo, Martha Patricia

    2013-01-01

    Los dientes supernumerarios son anomalías en el desarrollo dental que pueden estar o no asociadas a algún síndrome; su prevalencia oscila entre 0.3 y 3.8% y su incidencia entre 0.1 y 3.8% de acuerdo a la población de estudio. Estos dientes pueden presentarse en la línea media (mesiodens) en un 48.6%, siendo el más común de los dientes; le siguen los premolares con un 26.4%, los laterales con 11.1% y los molares en un 9.7%. Su diagnóstico se realiza mediante un estudio radiológico (radiografía...

  9. Dientes supernumerarios no sindrómicos: presentación de cuatro casos clínicos

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    Carlos Manuel Albornoz López del Castill

    2015-11-01

    Full Text Available Los dientes supernumerarios no sindrómicos son causa frecuente de alteraciones en la erupción de los dientes permanentes y adoptan una amplia gama de formas y posiciones clínicas. Estas alteraciones pueden minimizarse tras la extracción del supernumerario en el momento oportuno. El objetivo del presente artículo es dar a conocer las diferentes formas y las posiciones más raras que pueden adoptar los mesiodens, presentes en cuatro casos clínicos atendidos en la consulta de cirugía maxilofacial del hospital pediátrico de Camagüey, profundizando en el tratamiento de los mismos; en el período de septiembre de 2009 a septiembre de 2013. El rango de edad de los pacientes fue entre los siete y diez años y en todos los casos se realizó la extracción quirúrgica y remisión a ortodoncia. Se concluye que el diagnóstico precoz de estas anomalías es importante, pues cuando se realiza la extracción quirúrgica en una dentición mixta temprana, ayuda al alineamiento y erupción espontánea de los dientes adyacentes. Es muy interesante la descripción de estos casos por ilustrar las diferentes formas y posiciones que pueden adoptar los dientes supernumerarios y no haber encontrado reporte de casos similares en la literatura nacional revisada, de cuatro mesiodens en un mismo paciente.

  10. Dientes supernumerarios en el maxilar superior

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    Delvis Paez Delgado

    2013-07-01

    Full Text Available Se describe el caso clínico de un niño de 10 años de edad, atendido en la consulta de atención integral de la Clínica Estomatológica Provincial Docente de Santiago de Cuba, quien presentaba 2 dientes supernumerarios en el maxilar, detectados mediante la radiografía panorámica antes de comenzar el tratamiento ortodóncico. Se indicó la extracción quirúrgica y se observó el aspecto conoide que comúnmente presentan dichos dientes. El seguimiento clínico posterior reveló la ausencia de alteraciones en las estructuras anatómicas y una correcta cicatrización de los tejidos blandos.

  11. Múltiples dientes supernumerarios distomolares Multiple distomolars supernumerary teeth

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    F.J. Rodríguez Romero; S. Cerviño Ferradanes

    2009-01-01

    En una dentición normal, los dientes supernumerarios son aquellos descritos como adicionales a la serie. La etiología no esta clara. Se han descritos tanto en dentición primaria como en permanente, aunque son mas frecuentes en la dentición permanente. El objetivo de este informe es presentar un caso de una paciente con múltiples dientes supernumerarios distomolares. Cuartos molares bilaterales simétricos son sumamente raros.Supernumerary teeth are described as the teeth formed in excess of th...

  12. Dental anomalies in Dromiciops gliroides (Microbiotheria, Microbiotheriidae, Caenolestes fuliginosus and Rhyncholestes raphanurus (Paucituberculata, Caenolestidae Anomalías en la dentición de Dromiciops gliroides (Microbiotheria, Microbiotheriidae, Caenolestes fuliginosus and Rhyncholestes raphanurus (Paucituberculata, Caenolestidae

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    GABRIEL M MARTIN

    2007-12-01

    Full Text Available Dental anomalies are described after analyzing series of skulls and mandibles of three species of South American marsupials: the monito del monte {Dromiciops gliroides, the silky shrew-opossum {Caenolestes fuliginosus and the Chilean shrew-opossum {Rhyncholestes raphanurus. The anomalies are classified into three categories: (1 supernumerary or missing teeth in normal positions of the dental series, (2 morphological anomalies like teeth fusion or anomalous crown shape, and (3 presence of teeth in unusual positions. Cusp fusion and supernumerary teeth at the end of the toothrow have been observed predominantly in D. gliroides. A tendency to find supernumerary or missing teeth is observed between the procumbent incisors and the second lower premolars in caenolestids. Possible causes for these anomalies and their morphofunctional value are discussed. A comparison with other marsupials is presented and discussed. Isolation of local populations and its effects on genetic drift processes might explain the high percentage of dental anomaliesA partir del análisis de series de cráneos y mandíbulas del monito de monte {Dromiciops gliroides, el ratón marsupial sedoso {Caenolestes fuliginosus y la comadrejita trompuda {Rhyncholestes raphanurus, se describen las anomalías en la dentición (incisivos, premolares, molares, clasificándose de acuerdo a tres categorías: (1 dientes supernumerarios o faltantes en alguna posición, (2 anomalías morfológicas tales como fusión de dientes o variaciones en el número de raíces, y (3 presencia de dientes en posiciones inusuales. Se observa una tendencia al desarrollo de dientes supernumerarios en cenoléstidos, o pérdida de elementos dentarios en la mandíbula, principalmente entre los incisivos procumbentes y el segundo premolar. En D. gliroides, la tendencia es hacia la fusión de cúspides y la producción de dientes supernumerarios al final de la hilera molar superior (apareciendo como M5. Se discuten las

  13. Un nuevo protocolo de medicación intraconducto para dientes con necrosis pulpar y rizogénesis incompleta

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    Soares, Adriana de Jesus; Lima, Thiago Farias Rocha; Lins, Fernanda Freitas; Herrera Morante, Daniel Rodrigo; Gomes, Brenda Paula Figueiredo de Almeida; Souza-Filho, Francisco José de

    2014-01-01

    El trauma tiene un serio impacto en el desarrollo de la dentición de niños y jóvenes, pudiendo resultar en necrosis del diente permanente joven. El tratamiento más común para los casos de necrosis pulpar en dientes con rizogénesis incompleta es promover la apexificación. Esteartículo presenta el reporte de un caso clínico donde fue utilizada una medicación intraconducto (MIC) compuesta por la asociación de hidróxido de calcio, clorhexidina gel al 2% y óxido de zinc (2:1:2) para promover la fo...

  14. Biobanco de dientes humanos para investigación en odontología

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    Lina C Gonzáles Pita

    2014-07-01

    Full Text Available Un biobanco de dientes humanos es una entidad sin ánimo de lucro que recopila, almacena y administra dientes donados, y está vinculada a una institución de enseñanza, soportada por normas sanitarias, de bioseguridad, éticas y principios legales. El objetivo de este artículo es presentar la creación y parte del desarrollo del biobanco de dientes humanos con las especificaciones biológicas, éticas, legales y de bioseguridad, y la importancia de mantener los dientes extraídos en condiciones controladas, reproducibles y normalizadas, sin alterar su estructura, para suplir necesidades académicas y de investigación específicas. A partir de una revisión y análisis de literatura se organizan y adoptan normas legales y éticas según la legislación colombiana para la creación de un biobanco de dientes humanos en la Facultad de Odontología de la Universidad Nacional de Colombia.

  15. Agenesias dentarias, causas y frecuencia

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    Lazo, Gabriel Eduardo; Bustamante, Carlos Ariel; Segatto, Rodolfo Guillermo; Fingermann, Gloria Fanny; Gauzellino, Gustavo; García, María; Gentile, Ignacio Santiago; Caserio, Jorge Andrés; Ascani, Juan Pablo Amadeo; Marchioni, Aldana Pamela; Cazzola, Verónica Patricia; Lazo, María Virginia; Borrillo, Carlos Gastón; Scazzola, Marisa Isabel; Ferro, Marcela Lilián

    2017-01-01

    La agenesia dental consiste en la falta de formación y desarrollo de uno o más dientes. En el presente trabajo se realiza un análisis sobre 120 radiografías panorámicas de individuos de la ciudad de La Plata, cuyo rango de edad es de 4 a 14 años. El objetivo es determinar la frecuencia de presentación de agenesias dentarias en la mencionada población. La frecuencia global encontrada para las agenesias corresponde al 3,33%. Para la agenesia de los incisivos laterales superiores fue de 1,66%, i...

  16. Utilización de mantenedores de espacio en pacientes con pérdidas prematuras de dientes primarios

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    Natsibet Rivero García

    2012-02-01

    Full Text Available La pérdida prematura de dientes primarios ocurre cuando estos exfolian o son extraídos antes del momento fisiológico de recambio. Objetivo: determinar la asociación entre el uso de mantenedores de espacio y las pérdidas prematuras de dientes primarios. Materiales y métodos: se realizó el estudio descriptivo, retrospectivo, longitudinal y correlacional, de 109 registros diagnósticos de pacientes entre 3-9 años, atendidos en el Postgrado de Odontología Infantil de la UCV, excluyendo aquellos con síndromes o alteraciones sistémicas. Fue evaluado el estrato socioeconómico, dientes perdidos y el uso del mantenedor de espacio Se aplicaron pruebas estadísticas descriptivas, X2 de Pearson, y T de Student (p=0,05. Resultados: la edad de la muestra fue 4,93 ± 1,5 años. La prevalencia de pérdidas prematuras fue 70,90%, la media de dientes extraídos fue 3,75 ± 2,56. La causa más frecuente fue la caries 76,5% y el diente más afectado el 64 con 11,11%. El 72,12% de los pacientes utilizó mantenedor de espacio, siendo el más usado el fijo en 52,27% No hubo asociación estadísticamente significativa entre el estrato socioeconómico con el número de dientes afectados ni con el uso o no de mantenedor de espacio. Conclusión: la prevalencia de pérdidas prematuras para este estudio fue elevada debido a las características inherentes al tipo de servicio especializado en el que se brinda atención a pacientes con requerimientos de tratamiento complejo. En la mayoría de los casos se cumplió satisfactoriamente con el uso de mantenedores de espacio como elemento de prevención de maloclusiones.

  17. Manejo clínico de dientes supernumerarios en pacientes pediátricos

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    Gabriela José Jiménez de Sanabria

    2012-01-01

    Full Text Available Los dientes supernumerarios (DS son aquellos que se forman adicionalmente a la serie normal. Pueden ubicarse en cualquier área de los maxilares, siendo su forma cónica, tuberculada o suplementaria. Las alteraciones de oclusión frecuentemente asociadas son desplazamiento, retardo de erupción o impactación de los dientes vecinos. Objetivo: Describir la prevalencia de dientes supernumerarios, así como las consecuencias y terapéutica implementada para un grupo de pacientes pediátricos. Material y métodos: fueron evaluados los registros diagnósticos de 823 pacientes del Servicio de Ortodoncia Interceptiva, postgrado de Odontología Infantil U.C.V., determinando: forma, ubicación, consecuencias y tratamiento efectuado; los pacientes con síndromes o HLP fueron excluidos. Resultados: La prevalencia de dientes supernumerarios fue 5,47% con mayor proporción en el género masculino (1,8:1. La edad de diagnóstico fue 8,18 (±1,61. La forma cónica fue la más frecuente (45%, siendo el área apical anterior la más afectada (90%. El supernumerario produjo alteraciones en la posición de dientes adyacentes en 53,3%. El tratamiento incluyó odontectomía (63,3% y conformación del arco dental (87,5%. Sólo 4 casos requirieron tracción ortodóncica. Conclusión: la prevalencia de dientes supernumerarios en esta muestra fue mayor a la reportada por otros autores, con predilección por el género masculino. El tratamiento se realizó de forma sincronizada por parte del equipo interdisciplinario que incluyó Odontopediatra y Cirujano Bucal, determinando que la remoción oportuna del DS permite la erupción de los dientes adyacentes, siempre que el espacio disponible sea favorable.

  18. Banco de dientes: una alternativa para la rehabilitación de dientes temporales anterosuperiores

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    Débora Vasconcelos Pereira

    1997-12-01

    Full Text Available Existe una gran necesidad de rehabilitar el sector anterosuperior en pacientes con dentición temporal destruida por caries o traumatismos para reestablecer su función y estética y mejorar el perfil psicológico del niño. Se presenta la técnica de reposición de coronas y fragmentos para la reconstrucción de dientes temporales anterosuperiores a partir de un banco de dientes, realizada en la disciplina de odontopediatría de la Facultad de Odontología, en la Universidad de Sao Paulo. Se presentan diferentes indicaciones de esta técnica, para rehabilitación de coronas y fragmentos dentarios en el sector anterosuperior en la dentición temporal. El tiempo de seguimiento clínico radiográfico promedio fue de 6 meses, período en el cual se observaron excelentes resultados en relación con la estética, retención, resistencia y función, lo que demostró una alternativa de restauración en pacientes con destrucciones precoces en dientes temporales anterosuperiores.There is a great need to rehabilitate the anterosuperior sector in patients with temporal teething destroyed by caries or traumatisms so as to reestablish its function and aesthetics and to improve the psychological profile of the child. It is presented the technique of replacement of crowns and fragments for the reconstruction of temporal anterosuperior teeth starting from a tooth bank. This technique is applied within the discipline of odontopediatrics at the Faculty of Odontology, in the University of Sao Paulo. Different indications for the rehabilitation of crowns and dental fragments in the anterosuperior sector of temporal teething are shown. The average time of the clinical and radiological follow-up was 6 months. During this period, excellent results in connection with aesthetics, retention, resistance, and function were observed, which demonstrated that it is an alternative of restoration for patients with early destructions of temporal anterosuperior teeth.

  19. Influencia de los tratamientos microabrasivos sobre la resistencia adhesiva en dientes con fluorosis

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    Paola Mena Silva

    2015-12-01

    Full Text Available La búsqueda de tratamientos mínimamente invasivos y altamente estéticos para pacientes con fluorosis, ha llevado a buscar mecanismos para solucionar esta problemática, mediante la utilización de resinas como la primera opción. Sin embargo el principal problema del tratamiento, se centra en la poca adhesión debido a las características estructurales del esmalte fluorótico, en grados de fluorosis TF 1 al 3, el ácido no actúa correctamente, causando ausencia de grabado principalmente entre las estrías de Retzius, en las rugosidades y espacios adamantinos ocupados por detritus de materia orgánica y cúmulos de placa dentobacteriana, siendo necesario efectuar técnicas microabrasivas y desproteinizantes como paso previo a los procesos adhesivos. Así, el presente estudio pretendió determinar la resistencia adhesiva en dientes con fluorosis grados TF 2 y 3, empleando tres diferentes técnicas de abrasión adamantina, se seleccionaron 48 dientes divididos en 3 grupos de 16 muestras cada uno, 8 con grado TF2 y 8 con grado TF3. Las superficies del esmalte fueron preparadas mediante la técnica “microabrasión modificada”, la “técnica de microabrasión” y “Opalustre”, todos los grupos recibieron desproteinización con hipoclorito de sodio al 5% por un minuto. Posterior a lo cual fueron realizados los procesos adhesivos mediante sistema adhesivo y resina compuesta, sometiéndose posteriormente a pruebas de cizallamiento. Los resultados analizados mediante testes de ANOVA y T de Student no determinaron una diferencia estadísticamente significativa entre los grupos, la facilidad en los protocolos de aplicación debe ser considerada en la elección de la técnica, sin embargo resulta importante su ejecución en dientes afectados por fluorosis.

  20. Estudio de la enfermedad periodontal y la higiene bucal en dientes en desoclusión Study of periodontal disease and oral higiene in dysocclusion

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    Jorge Sotres Vázquez

    2005-12-01

    Full Text Available Se realizó una investigación en 50 pacientes que acudieron al Servicio de Periodoncia de la Clínica Estomatológica “Hermanos Gómez”. Se realizó un examen clínico para evaluar la presencia de contactos oclusales en los dientes presentes. El grado de higiene bucal se midió mediante el índice de higiene bucal de Greene y Vermillion , y la prevalencia y la gravedad de la enfermedad periodontal mediante el índice periodontal de Russell . En los casos en que los dientes no ocluían se señaló la causa . La desoclusión dental mostró una alta incidencia, con el 27,82 % de los dientes sin contactos oclusales ; la causa más frecuente fue la ausencia de dientes antagónicos (78,1 % . En los casos de desoclusión se empeoró la higiene bucal. Tanto la prevalencia como la gravedad de la enfermedad periodontal aumentaron en los dientes que no ocluían.A research was undertaken among 50 patients that received attention at the Periodontics Service of “Hermanos Gómez” Dental Clinic. A clinical examination was made to evaluate the presence of occlusal contacts in the present teeth. The oral higiene degree was measured by Greene and Vermillion's oral higiene index, whereas the the prevalence and severity of the periodontal disease was measured by using Russell's periodontal index. In those cases in which the teeth did not occlude, the cause was mentioned. Dysocclusion showed a high incidence with 27.82 % of the tooth without occlusal contacts. The most frequent cause was the absence of antagonic tooth (78.1 %. Oral higiene was worse in the cases presenting dysocclusion. Both, the prevalence and the severity of the periodontal disease increased in the tooth that did not occlude.

  1. Asociación entre agenesia dental y maloclusión en pacientes pediátricos

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    A. Carolina Medina

    2013-07-01

    Full Text Available Introducción: La agenesia dental es la anomalía del desarrollo más frecuente en el ser humano, asociándose a maloclusiones y alteraciones funcionales. Objetivo: El objetivo de la presente investigación es determinar la asociación entre la agenesia de dientes permanentes y la presencia de maloclusiones en pacientes pediátricos en el área Metropolitana de Caracas, Venezuela. Material y métodos: Fueron evaluados 1.188 radiografías panorámicas y 648 registros ortodóncicos de pacientes sanos con edades entre 5 y 18 años, registrando agenesia de dientes permanentes, exceptuando terceros molares. La maloclusión se diagnosticó según Angle. Fueron calculados estadísticos descriptivos, diferencias entre promedios y correlaciones entre variables (t de Student, rho de Pearson, p=0,05, odds ratio. Resultados: La prevalencia de agenesia fue 5,6%, siendo la media 1,64 y afectando mayormente al sexo femenino (1,44:1. Los dientes más afectados fueron segundos premolares inferiores (35,19%, e incisivos laterales superiores (30,55%. La prevalencia de maloclusión fue mayor en el grupo con agenesia dental (Clase I 52%, Clase II 31%, Clase III 17% al comparar con el grupo control (Clase I 77%, Clase II 14%, Clase III 9%; habiendo correlación estadísticamente significativa entre el número de dientes ausentes y Clase III. Conclusión: La prevalencia y distribución de agenesia dental variaron entre géneros, siendo el femenino el más afectado. Hubo correlación positiva estadísticamente significativa entre el número de dientes afectados y la maloclusión Clase III.

  2. The most commonly used drugs during early childhood and their relationship to the incisor molar hypomineralization syndrome : experimental study in mice= Relación entre los fármacos de uso más frecuente en la primera infancia y la aparición del síndrome de hipomineralización incisivo-molar: estudio experimental en ratones

    OpenAIRE

    Serna Muñoz, Clara

    2017-01-01

    El término hipomineralización incisivo molar (MIH) fue descrito por primera vez por Weerheijm, Jälevik y Alaluusua (2001), y definitivamente adoptado por la comunidad dental internacional como resultado de un consenso tras varias discusiones sobre un defecto del desarrollo del esmalte en el Congreso de la Academia Europea de Odontopediatría celebrado en Atenas, en 2003 (Weerheijm et al., 2003). La MIH es un defecto cualitativo del esmalte, que afecta a los primeros molares y los incisivos per...

  3. Análise comparativa da distribuição de tensões em incisivo central superior, restaurado com diferentes sistemas de pinos intra-radiculares

    OpenAIRE

    Oliveira, Luana Cristina Araújo de [UNESP

    2002-01-01

    Neste trabalho é proposto analisar a distribuição de tensões produzidas na dentina radicular do incisivo central superior restaurado com diferentes sistemas de pinos intra-radiculares, através dos Métodos de Fotoelasticidade e Elementos Finitos. Esta análise foi realizada para os seguintes sistemas de pinos intra-radiculares: fibra de carbono, fibra de vidro, zircônio, aço inoxidável, titânio e metálico fundido (Liga de Cu-Al), o dente hígido foi utilizado como controle. Em ambos método foi c...

  4. 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.

  5. Exodoncia de diente supernumerario, canino en transposición y enucleación de odontoma complejo: Reporte de Caso

    OpenAIRE

    Perea Paz, Miguel; Aliaga Del Castillo, Rosalinda; Aliaga Del Castillo, Arón

    2014-01-01

    Las anomalías dentarias más frecuentes e importantes que afectan a los niños son la presencia de piezas supernumerarias, piezas retenidas y odontomas. Algunos dientes retenidos se pueden encontrar en  transposición. Reportamos el caso de una paciente de sexo femenino de 11 años de edad con presencia de diente supernumerario, canino en transposición y odontoma complejo situados en la hemiarcada derecha del maxilar superior. El motivo de consulta fue por la presencia de dientes anteriores sobre...

  6. Análisis cuantitativo de adaptación de pernos fibra de vidrio cilíndricos y cilíndrico-cónicos en diferentes anatomías de dientes unirradiculares (In Vitro). Pautas para diseñar nuevas técnicas.

    OpenAIRE

    Noroña, Diego Mariano

    2014-01-01

    Los dientes tratados endodónticamente poseen un riesgo mayor de fallas biomecánicas al compararlos con dientes vitales. El perno intrarradicular individualizado a la anatomía del conducto radicular es la mejor forma de hacer funcionar todo como un monobloque. Esta investigación in vitro analizó y cuantificó las áreas de adaptación entre los postes y las paredes del...

  7. Estudio de la prevalencia y posibles factores etiológicos relacionados con la Hipomineralización incisivo molar (mih) en un grupo de niños y adolescentes

    OpenAIRE

    Martínez Gómez, Teresita Patricia

    2014-01-01

    La hipomineralización incisivo molar (MIH) por sus siglas en inglés, es un defecto cualitativo del desarrollo del esmalte de uno o cuatro primeros molares permanentes, frecuentemente asociado con defecto en los incisivos. Clínicamente, se observa como una alteración en la translucides del esmalte, caracterizado por opacidades demarcadas cuyos bordes bien definidos separa claramente el esmalte afectado del normal adyacente, la zona cervical de la corona anatómica mantiene una aparaiencia y co...

  8. Corte y sellado reversible de dientes para obtener superficies internas de esmalte incólumes

    Directory of Open Access Journals (Sweden)

    Ana Milena Santiago-Medina

    2015-07-01

    Full Text Available Las superficies internas de los dientes, que se obtienen por cortes con discos, están generalmente desorganizadas por los giros, la velocidad y la rugosidad del disco. El calor altera la superficie y el agua de la refrigeración la composición química porque disuelve los componentes. En estudios de difusión, el perfil se borra por el corte, lo que anula resultados. Objetivo: desarrollar un método de sellado de superficies internas, ya cortadas antes de los ensayos de difusión, sin dejar trazas químicas o partículas. Materiales y metedos: se probó in vitro la habilidad de cuatro materiales de sellado con 40 especimenes, provenientes de 20 coronas de terceros molares, cortadas sagitalmente. Los especímenes se distribuyeron aleatoriamente en cuatro grupos (n = 10: G1: Teflón (Topex®, G2: Tela de caucho (Dental DAM®, G3: película de cloruro de polivinilo (Vinilpel® y G4: Cinta aislante (Tesa®. Se usó una solución de azul de metileno (AM al 2% por 6 días como indicadora de filtración. Por observación visual de cada muestra, se le asignó un valor (sí o no dependiendo de la presencia o ausencia de cualquier punto MB sobre la superficie de sellado. Los resultados fueron analizados siguiendo un modelo estadístico de respuesta binomial. Resultados: Siguiendo los procedimientos descritos, el teflón es el único material que previene la filtración de AM en la superficie interna expuesta por el corte. Conclusión: Se propone un protocolo de sellado reversible de las superficies internas con teflón, previo al corte de los dientes, para no alterar los resultados experimentales.

  9. Má oclusão Classe I de Angle com agenesia de incisivos laterais

    OpenAIRE

    Franco,Fernanda Catharino Menezes

    2011-01-01

    O planejamento ortodôntico de pacientes com agenesia de incisivos laterais envolve considerações estéticas e funcionais de grande relevância para um resultado clínico satisfatório. Tanto o fechamento dos espaços correspondentes aos dentes ausentes quanto sua abertura ou manutenção oferecem vantagens e desvantagens que devem ser avaliadas de acordo com as características individuais do paciente. Fatores importantes que influenciam o planejamento são o padrão esquelético, o tipo de má oclusão e...

  10. Manejo endodóntico de incisivos mandibulares con geminación

    Directory of Open Access Journals (Sweden)

    Jose Elías Florez Ariza

    2014-06-01

    Full Text Available Las anomalías dentales pueden ser clasificadas en distintos grupos: anomalías de volumen, anomalías de número, anomalías de forma, anomalías de posición y anomalías por unión. Dentro de las últimas distinguimos entre fusión, geminación, concrescencia, coalescencia y anquilosis alvéolo- dentarias. La geminación es más frecuente en los dientes anteriores, aunque también puede afectar a premolares y molares, siendo una anomalía por unión infrecuente (prevalencia 0,5%. Se presenta el caso de un joven de 25 años sin antecedentes médicos de interés que acude a consulta a ortodoncia por inconformidad estética. El ortodoncista diagnostica clínica y radiográficamente germinación en diente 32 y es remitido a rehabilitación para que a través de tallado se confeccione una corona única con morfología de lateral inferior izquierdo y así ganar espacio para los movimientos ortodónticos, además fue necesaria la realización de tratamiento de conducto por parte del endodoncista. (Duazary 2009-II 154-158.

  11. Estudo da viabilidade do preparo direto para descanso de cíngulo em incisivo central superior

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    ALENCAR José Freire de

    2000-01-01

    Full Text Available Esta pesquisa teve como finalidade estudar a viabilidade do preparo direto para descanso em cíngulo de incisivo central superior, por intermédio de processamento de imagem. Foram reproduzidos dez dentes íntegros, montados em um suporte de alumínio com resina acrílica e distribuídos entre cinco especialistas, que executaram os preparos para descanso. Em seguida, os corpos-de-prova foram cortados ao longo de suas coroas, tendo como guia um corte inicial, feito no centro da borda incisal de cada dente. O preparo foi então dimensionado, estabelecendo-se medidas lineares e angulares que permitissem uma análise comparativa entre o perfil original do dente e aquele após o preparo, enquanto se determinava a perfuração ou não da camada de esmalte. Todas as observações foram feitas, digitalizando-se os perfis e processando as imagens num programa específico. Dos cinqüenta modelos preparados, seguindo critérios estabelecidos, trinta e três perfuraram a camada de esmalte. Sendo assim, o incisivo central superior não está indicado para receber preparo direto para descanso de cíngulo.

  12. Modelación del contacto entre dos pares de dientes en las coronas de molinos de caña//Modeling of contact between two pairs of teeth in the sugar cane mills gears

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    Abdel Mendoza‐Fernández

    2013-09-01

    Full Text Available En el trabajo se propone un mecanismo equivalente para la modelación del funcionamiento de las coronas de molino de caña de azúcar cuando teóricamente hay dos pares de dientes en contacto. A través del análisis de movilidad del mecanismo se demuestra que no es posible el contacto simultaneo entre dos pares de dientes y que el coeficiente de recubrimiento en estos engranes es igual o menor que la unidad. A partir de los resultados del análisis cinemático del contacto entre un par de dientes, y combinándolo con la modelación del contacto entre dos pares de dientes se demuestra que el coeficiente de recubrimiento real en estos engranajes es menor que la unidad y se producen impactos entre los dientes al inicio del contacto.Palabras claves: molinos de caña, coronas de molinos, coeficiente de recubrimiento, engranajes._________________________________________________________________________________AbstractThe paper proposes an equivalent mechanism for modeling the functioning of the crowns of sugar cane mill when theoretically there are two pairs of teeth in contact. Through mobility analysis of the mechanism is demonstrated that is not possible the simultaneous contact between two pairs of teeth and that the coating coefficient of these gears is equal or less than unity. Combining kinematic analysis results for the contact between a pair of teeth with the modeling the contact between two pairs of teeth, it is demonstrated that gear ratio of these gears is less than unity and impacts occur between the teeth at the start of contact.Key words: sugar cane mills, sugar cane mills gears, contact ratio, gears.

  13. Regeneración ósea guiada: nuevos avances en la terapéutica de los defectos óseos

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    Verónica Gómez Arcila

    Full Text Available Introducción: el procedimiento de regeneración ósea guiada ha demostrado ser una técnica exitosa para promover el llenado de defectos óseos presentes, así como para aumentar las dimensiones de rebordes alveolares atróficos previo a rehabilitación protésica convencional o implanto soportada. Objetivo: describir la utilización clínica de injerto aloplástico de b-fosfato tricálcico como material de relleno en la regeneración de defectos óseos alveolares. Presentación del caso: se presentó el caso de una paciente femenina de 57 años de edad quien acudió a la consulta odontológica por presencia de supuración en un diente anterosuperior, como consecuencia de un proceso infeccioso apical. Al examen clínico se observó resto radicular de incisivo central superior izquierdo e incisivo lateral superior izquierdo; radiográficamente se observó fractura radicular de incisivo central superior derecho. Posterior a la extracción de los restos radiculares, se empleó la técnica de regeneración ósea guiada, utilizando injerto aloplástico de b-fosfato tricálcico con una membrana de colágeno reabsorbible. Tres meses posteriores al tratamiento, se observó aumento en altura y anchura del reborde alveolar, con lo que se logró la conformidad estética y funcional deseada. Conclusión: el caso presentado revela resultados clínicos satisfactorios gracias a la neoformación de hueso observada y a la planificación adecuada del tratamiento con regeneración ósea guiada, por lo que el uso de injerto óseo, específicamente el injerto aloplástico b-fosfato tricálcico, en combinación con las membranas de barrera, se sugiere para el manejo de los defectos óseos alveolares.

  14. Tratamientos ortodóncico-quirúgicos para dientes anquilosados

    OpenAIRE

    Malpartida Montes, Ana

    2016-01-01

    Objetivo: Analizar y comparar las distintas técnicas ortodóncico-quirúrgicas para el reposicionamiento de dientes anquilosados, así como valorar las ventajas y desventajas, limitaciones, indicaciones y contraindicaciones de cada una de ellas. Material y método: La búsqueda de información se hizo en Pubmed, Medline, Google Académico y revistas como la American Journal of Dentofacial Orthopedics and Orthodontics. En una primera fase de búsqueda, seleccionamos 19 artículos para la fracción in...

  15. Comportamiento de traumatismos dentoalveolares en niños deportistas del área "Ciro Frías", del municipio de Arroyo Naranjo

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    María Elena Quiñones Ybarría

    Full Text Available Introducción: los traumatismos dentoalveolares constituyen una de las principales urgencias estomatológicas. Objetivo: caracterizar el comportamiento de los traumatismos dentarios en niños deportistas del área "Ciro Frías". Métodos: se realizó un estudio observacional descriptivo, de corte transversal, en deportistas menores de 19 años del área "Ciro Frías", del municipio Arroyo Naranjo, La Habana, desde febrero de 2011 hasta febrero de 2012. El universo estuvo constituido por 57 niños. Se utilizó un formulario de datos creado por los autores y validado por un comité de expertos; se realizó examen bucal y facial; se vaciaron los datos y se procesaron utilizando estadística descriptiva. Las variables estudiadas fueron: edad, sexo, deporte, momento del traumatismo, dientes lesionados, localización en la arcada, tipo de trauma dentario, etiología, asistencia al estomatólogo y tratamiento. Resultados: los niños que más traumatismos dentarios presentaron fueron los de 12 a 14 años (45,6 % y el sexo más afectado fue el masculino (77,2 %. Los traumas ocurrieron principalmente fuera del entrenamiento (61,4 % y el deporte con más niños afectados fue el Karate (19,3 %. Los dientes más dañados fueron los incisivos centrales superiores (62,9 %. La fractura no complicada de la corona (32,3 % fue la lesión más acentuada. La etiología principal de los traumas fue la práctica de deportes (36,8 %. El 68,4 % de los niños no recibieron tratamiento. Conclusiones: predominaron los traumas en el sexo masculino, entre 12 a 14 años, fuera del entrenamiento. El deporte con más niños afectados fue el Karate. Los dientes más lesionados fueron los incisivos centrales superiores. Los traumatismos más frecuentes fueron las fracturas no complicadas de la corona y la infractura del esmalte. Las causas de traumatismos dentarios más frecuentes fueron la práctica de deportes y las caídas. Prevalecieron los niños que no asistieron a consulta

  16. Uso de osteocoral como material de implante en bolsas infraóseas de dientes Monorradiculares

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    . Yamilé Hernández Alemán,

    1999-12-01

    Full Text Available Se evaluó la eficacia del osteocoral como material de implante en el tratamiento de bolsas infraóseas de dientes monorradiculares. Se realizaron 18 injertos en 17 dientes con defectos angulares, en 6 pacientes de ambos sexos; 9 implantes correspondieron al grupo control con hidroxiapatita y 9 al grupo de estudio que fue implantado con osteocoral. Se realizó preparación inicial que incluyó: remoción de cálculos y pulido de las superficies dentarias, educación y motivación sobre el tratamiento recibido, corrección del cepillado igual o mayor al 80 % en la remoción de placa dentobacteriana. Se realizó el implante mediante operación a colgajo, con sutura y colocación de apósito periodontal. Se realizaron radiografías de control a los 14 días, a los 3 y 6 meses. Se controló sistemáticamente la higiene bucal. A los 6 meses se registraron nuevamente los indicadores clínicos. El análisis final de los resultados mostró una disminución estadísticamente significativa en el índice gingival, profundidad de la bolsa al sondeo y movilidad dentaria para ambos materiales implantológicos. No se reportaron grandes diferencias entre éstos para este tamaño de muestra, no hubo reacciones adversas y se logró la permanencia del implante de osteocoral, por lo que se consideró efectivo el tratamiento.Effectivenes of osteocoral as implant material was assessed to treat infraosseous pockets of multirooted teeth. 18 grafts were inserted in 17 teeth with angular defects in 6 patients of both sexes; 9 implants corresponded to control group (hydroxiapatite and 9 corresponded to study group (osteocoral. Initial preparation included: removal of calculus and polishing of dental surface, education and motivation about treatment applied, correction of tooth-brushing equal or greater 80 % in removal of dentobacterial plaque. Implant was inserted by flap surgery using suture and placement of periodontal dresssing. Control X-rays were made within 14 days

  17. Morfología comparada de los dientes humanos fósiles de Ibeas (Sierra de Atapuerca, Burgos

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    Bermúdez de Castro, J. M.

    1987-08-01

    Full Text Available This paper contains a morphological and comparative study of 68 human fossil teeth recovered from the "Sima de los Huesos" site of the Cueva Mayor-Cueva del Silo karst system (Sierra de Atapuerca, Ibeas de Juarros, Burgos. The morphology of the Ibeas teeth conforms with a pattern of expansion of the anterior dentition characterizing all the Middle Pleistocene human populations, and with a pattern of structural reduction of the posterior teeth characterizing the European population of that period. The Ibeas teeth share several morphological traits with those of other European, North African and Asian Middle Pleistocene fossils. However, the tooth morphology of the European group, in which the Ibeas fossils are included, shows remarkable differences with that of the other groups. This fact permits to reinforce the thesis that a distinctive hominid lineage was established in Europe during the Middle Pleistocene. On the other hand, the Ibeas teeth bring forward new evidence to support the hypothesis of a close filogenetic relationship between the Middle Pleistocene European population and the Nearderthals and, accordingly, of a local evolution during that period and the Early Upper Pleistocene.Este trabajo contiene el estudio morfológico comparado de un total de 68 dientes humanos fósiles recuperados en la Sima de los Huesos, yacimiento situado en el sistema kárstico Cueva Mayor-Cueva del Silo (Sierra de Atapuerca, Ibeas de Juarros, Burgos. La morfología de los dientes de Ibeas se ajusta a un modelo de expansión de la dentición anterior que caracteriza a todas las poblaciones humanas del Pleistoceno medio, y a un modelo de reducción estructural de la dentición posterior que caracteriza a la población europea de dicho periodo. Los dientes de Ibeas comparten diversos rasgos morfológicos con los dientes de otros fósiles mesopleistocenos de Europa, norte de Africa y este de Asia. Sin embargo, el grupo europeo, en el que se incluyen los f

  18. Reingeniería de la geometría desconocida de engranajes cónicos con dientes rectos y curvilíneos.

    OpenAIRE

    G. González Rey; S. A. Marrero Osorio

    2008-01-01

    En el trabajo se presenta un procedimiento para dar solución al problema de solución inversa asociado con la determinación de la geometría desconocida del dentado de un engranaje cónico con ejes ortogonales y dientes de altura proporcional en base a cálculos de ingeniería de engranajes y con empleo de mediciones con herramientas de taller. El procedimiento propone un método práctico, con asistencia de un cálculo organizado linealmente y una búsqueda exhaustiva, para obtener los parámetros fun...

  19. La caries del biberón. Qué es y cómo prevenirla

    OpenAIRE

    Sánchez Molins, Meritxell; Ustrell i Torrent, Josep Maria, 1953-

    2001-01-01

    La caries del biberón es la aparición brusca de caries en los incisivos y molares temporales, relacionadas con el hábito de succionar el chupete o el biberón, impregnados de sustancias cariogénicas. Afecta a los niños en las primeras etapas de la vida. Los dientes de leche son fundamentales para diferentes funciones como la masticación y el habla. Este trabajo revisa cuáles son sus causas más comunes y las medidas preventivas más indicadas.

  20. Combinación quirúrgica: una necesidad en Odontopediatría

    OpenAIRE

    Roberta Dias dos Santos; Milena Tavares de Carvalho; Patrícia Maria Coelho; Rafael de Queiroz Moura; Kariza Vargens Diniz Correia

    2017-01-01

    Introducción: El Mesiodens es un diente supernumerario que se forma en la línea media entre los incisivos centrales superiores, más frecuentemente en la dentición permanente y en pacientes de sexo masculino. Su etiología es bastante desconocida, pero la hiperactividad de la lámina dentaria es la teoría más aceptada. Se presenta asociado a otras complicaciones, como el diastema interincisivo, que puede también estar asociado a la inserción anormal del frenillo labial superior, provocando alter...

  1. Sistema Procera : una alternativa estética para dientes anteriores

    OpenAIRE

    Ticianeli, Márcio Giampá; Oliva, Eduardo Andrade de; Sarabia Ouiroz, Ana Maria; Cláudio, José; Segalla, Martins

    2014-01-01

    Actualmente, el uso de restauraciones cerámicas constituye una excelente alternativa para eltratamiento de reconstrucción de las estructuras dentarias perdidas. Estas restauraciones tienenvarias ventajas tales como: resistencia a la compresión, estabilidad de color, radiopacidad, bajaconducti vidad térmica y eléctrica; además de ser químicamente inertes. Adicionalmente losmateriales cerámicos simulan la apariencia de los dientes naturales, reproduciendo la textura,profundidad del color y tran...

  2. Imágenes en odontología clínica. Perlas del esmalte

    Directory of Open Access Journals (Sweden)

    Ignacio Roa

    2017-07-01

    Full Text Available Una mujer de 19 años de edad asiste a la consulta odontológica con indicación de exodoncia del diente 1.8. Luego del acto quirúrgico se examinó el diente y se observó la presencia de dos perlas del esmalte a nivel radicular. Las perlas de esmalte son una anomalía del desarrollo dental, que se presentan como glóbulos ectópicos de esmalte en la superficie radicular. La prevalencia media de perlas de esmalte es 2,69%; teniendo predilección por los molares y rara vez se asocian con premolares, caninos o incisivos. La teoría sugiere que se desarrollan debido a presencia de remanentes de la vaina epitelial radicular (de Hertwig. Adquieren real relevancia debido a su asociación como factor retentivo de placa subgingival y a enfermedad periodontal localizada.

  3. Antibióticos para prevenir las complicaciones posteriores a la extracción de dientes

    Directory of Open Access Journals (Sweden)

    2014-05-01

    Hay pruebas de que los antibióticos profilácticos reducen el riesgo de infección, alveolitis y dolor posterior a la extracción del tercer molar y dan lugar a un aumento de los efectos adversos leves y transitorios. No está claro si las pruebas de esta revisión son generalizables a los pacientes con enfermedades concomitantes o inmunodeficiencia, o a los pacientes sometidos a la extracción de dientes debido a la caries grave o a la periodontitis. Sin embargo, los pacientes en mayor riesgo de infección presentan mayor probabilidad de beneficiarse con los antibióticos profilácticos debido a que es probable que las infecciones en este grupo sean más frecuentes, se asocien con complicaciones y sean más difíciles de tratar. Debido al aumento de la prevalencia de bacterias resistentes al tratamiento con los antibióticos disponibles actualmente, los médicos deben considerar cuidadosamente la probabilidad de que el tratamiento de 12 pacientes sanos con antibióticos para prevenir una infección cause más daños que beneficios.

  4. Manejo endodóntico de incisivos mandibulares con geminación

    OpenAIRE

    Jose Elías Florez Ariza; Raúl Fortich Carballo; Antonio Díaz Caballero; Eduardo Covo Morales

    2014-01-01

    Las anomalías dentales pueden ser clasificadas en distintos grupos: anomalías de volumen, anomalías de número, anomalías de forma, anomalías de posición y anomalías por unión. Dentro de las últimas distinguimos entre fusión, geminación, concrescencia, coalescencia y anquilosis alvéolo- dentarias. La geminación es más frecuente en los dientes anteriores, aunque también puede afectar a premolares y molares, siendo una anomalía por unión infrecuente (prevalencia 0,5%). Se presenta el caso de un ...

  5. Tratamiento Endodóntico no Instrumentado en dientes deciduos

    OpenAIRE

    Perona-G; Mungi-S

    2014-01-01

    Teniendo en cuenta la complejidad del tratamiento pulpar en una pieza decidua y diversos factores que determinan el éxito clínico como son la anatomía de una pieza decidua, el proceso de reabsorción ya sea de origen fisiológico o por una infección odontogénica, la conducta del paciente, la técnica empleada y la pericia del operador; es de suma importancia que en la práctica odontopediátrica se tenga en cuenta ciertos procedimientos que aseguren la presencia del diente en boca hasta su exfolia...

  6. Profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo

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    Rubén Muñoz Delgado

    2015-01-01

    Full Text Available Objetivo: Evaluar la relación entre el ajuste marginal y la profundidad del surco gingival en dientes primarios restaurados con coronas de acero cromo. Métodos: Se midió la profundidad del surco gingival de 114 dientes primarios restaurados con coronas de acero cromo en 67 niños, ambos sexos, de 3 a 6 años de edad de la clínica de Estomatología Pediátrica de la UATx, México. La población en estudio fue dividida en tres grupos: a experimental (n=30, b control (n=8, y c control negativo (n=29. Previo consentimiento informado se tomaron los índices de placa (LöeSilness 1967 e índice gingival en seis superficies; se midió el surco gingival con sonda periodontal y las coronas de acero cromo fueron evaluadas clínica y radiográficamente según su ajuste marginal y longitud cervical. Resultados: Los índices de placa y gingival no mostraron diferencias significativas para los grupos experimental y control negativo. El 34% de las coronas mostraron buen ajuste marginal, 33% un mal ajuste, 10.5% cortas, 7.9% largas y el 14% otro tipo de mal ajuste. La profundidad del surco gingival fue estadísticamente significativa para el primer y segundo molar inferior derechos y en los caninos inferiores (p >0.05; la superficie disto-vestibular presentó la mayor profundidad del surco gingival (2.34 mm, siendo estadísticamente significativa (p>0.05. Conclusiones: La profundidad del surco gingival fue mayor en los dientes rehabilitados con coronas de acero cromo mal ajustadas y sobre contorneadas (largas. La presencia de placa bacteriana y gingivitis estuvo relacionada con las coronas de acero cromo mal ajustadas.

  7. Injerto de tejido conectivo en recesión gingival de incisivo

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    Luis Fang Mercado

    2013-10-01

    Full Text Available ResumenLa recesión gingival es definida como la ubicación del margen gingival apical a la unión amelocementaria de uno o más dientes. Esta deformidad apical ocasiona generalmente sensibilidad radicular, pobre apariencia estética y lesiones cervicales cariosas por lo que los pacientes pueden preguntar de manera frecuente a los clínicos por procedimientos de recubrimiento radicular. Existen dos grandes grupos de causas de recesión gingival, las que se originan de enfermedad periodontal y de origen traumático, además, se consideran ciertos factores y se les clasifica como factores predisponentes y precipitantes desencadenantes. Patológicamente las recesiones gingivales están ocasionadas por la destrucción de tejido conectivo de la encía, lo cual ocasiona una disminución del flujo sanguíneo a nivel gingival. Se desarrollan varias técnicas con el mismo fin, dentro de estas están el colgajo pediculado, injerto gingival libre, injerto de tejido conectivo y la regeneración tisular guiada. Las condiciones de éxito en el tratamiento de las recesiones gingivales, descansan en el conocimiento de su etiología y de las posibilidades de cicatrización de acuerdo a las diferentes técnicas quirúrgicas consideradas para corregirlas. Los objetivos a considerar en el tratamiento de las recesiones son: mejorar la estética, recubrir las zonas radiculares expuestas y lograr estabilidad clínica. Se presenta un caso clínico donde se utilizó el enfoque del injerto de conectivo subpediculado en un diente único para crear encía adherida y a la vez intentar cubrir una recesión en diente inferior anterior. (DUAZARY 2011 No. 2, 206 - 212.AbstractGingival recession is defined as the location of gingival margin apical to the CEJ one or more teeth. This deformity causes apical usually root sensitivity, poor appearance aesthetics and carious cervical lesions so that Patients may wonder procedures root coverage. There are two main groups causes of

  8. Valoración "in vitro" de las fuerzas de adhesión de un sistema adhesivo convencional y otro autograbante en esmalte de dientes temporales y permanentes

    OpenAIRE

    Herrera Martínez, Gilberto de Jesús

    2012-01-01

    El presente trabajo trata de aportar más información sobre un nuevo adhesivo autograbante a esmalte de dientes temporales y permanentes. El objetivo es valorar las fuerzas de adhesión en MPa de los sistemas adhesivos (convencional y autograbante),en el esmalte de dientes temporales y permanentes. Métodos: utilizando una muestra de 160 dientes (temporales y permanentes)a nivel de la estructura del esmalte, divididos en cuatro grupos, no tomándose en cuenta para el criterio de selección la p...

  9. Remanente de la obturación endodóntica en dientes restaurados con retenedor Intra-radicular y su relación con la condición periapical post-tratamiento

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    Cristian David Gil García

    2016-07-01

    Full Text Available No hay evidencia clínica para afirmar que 4-5mm es la longitud aceptada del remanente de obturación endodóntica en dientes restaurados con retenedor intraradicular (RI. Objetivo: Estimar la relación entre el remanente del material de obturación endodóntica en dientes restaurados con RI y la condición periapical post-tratamiento bajo observación en imágenes tomográficas (CBCT. Métodos: Estudio observacional, descriptivo y de corte transversal. Se incluyen dientes permanentes, con obturación endodóntica óptima y restaurados con RI observados en periodos >1año. Se excluyen raíces con espacio visible entre el retenedor y el material obturador. Dos observadores entrenados clasificaron la variable dependiente: condición periapical en normalidad o en enfermedad. Para la variable explicativa se realizaron mediciones continuas del remanente. Análisis estadístico: Una Prueba-F, significativa al 5%, determinó la variabilidad inter-examinador. Se realizó un análisis en Componentes Principales (ACP para promediar mediciones del remanente de obturación. Un Modelo de Regresión Logística (MRL, con 95% confianza (IC, estimó la relación entre el remanente y el resultado del tratamiento. Resultados: 103 raíces, de 68 pacientes, conformaron la muestra. La Prueba-F no registró diferencias significativas inter-examinador al cuantificar la variable explicativa, (Vp-Coronal=0,767; Vp-Sagital=0,483; Vp-Axial=0,623 y la dependiente (Vp=0,487. Un MRL determinó la no asociación entre la longitud del remanente de obturación y la condición periapical post-tratamiento (OR=0.69, IC95%; 0.244-2.33, P=0.126. En el Corte sagital oblicuo se observó, al 10% de significancia, una relación inversamente proporcional por cada unidad de aumento en la longitud del remanente y la probabilidad de fracasar disminuye en 17.6% (OR=0.36, IC95%; 0.009-13.254, P=0.61. Conclusión: No existe relación entre la longitud del remanente y la condición periapical

  10. Remanente de la obturación endodóntica en dientes restaurados con retenedor Intra-radicular y su relación con la condición periapical post-tratamiento

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    Cristian David Gil García

    2016-07-01

    Full Text Available No hay evidencia clínica para afirmar que 4-5mm es la longitud aceptada del remanente de obturación endodóntica en dientes restaurados con retenedor intraradicular (RI. Objetivo: Estimar la relación entre el remanente del material de obturación endodóntica en dientes restaurados con RI y la condición periapical post-tratamiento bajo observación en imágenes tomográficas (CBCT. Métodos: Estudio observacional, descriptivo y de corte transversal. Se incluyen dientes permanentes, con obturación endodóntica óptima y restaurados con RI observados en periodos 1año. Se excluyen raíces con espacio visible entre el retenedor y el material obturador. Dos observadores entrenados clasificaron la variable dependiente: condición periapical en normalidad o en enfermedad. Para la variable explicativa se realizaron mediciones continuas del remanente. Análisis estadístico: Una Prueba-F, significativa al 5%, determinó la variabilidad inter-examinador. Se realizó un análisis en Componentes Principales (ACP para promediar mediciones del remanente de obturación. Un Modelo de Regresión Logística (MRL, con 95% confianza (IC, estimó la relación entre el remanente y el resultado del tratamiento. Resultados: 103 raíces, de 68 pacientes, conformaron la muestra. La Prueba-F no registró diferencias significativas inter-examinador al cuantificar la variable explicativa, (Vp-Coronal=0,767; Vp-Sagital=0,483; Vp-Axial=0,623 y la dependiente (Vp=0,487. Un MRL determinó la no asociación entre la longitud del remanente de obturación y la condición periapical post-tratamiento (OR=0.69, IC95%; 0.244-2.33, P=0.126. En el Corte sagital oblicuo se observó, al 10% de significancia, una relación inversamente proporcional por cada unidad de aumento en la longitud del remanente y la probabilidad de fracasar disminuye en 17.6% (OR=0.36, IC95%; 0.009-13.254, P=0.61. Conclusión: No existe relación entre la longitud del remanente y la condición periapical

  11. Diente cónico: presentación de dos casos

    OpenAIRE

    Carmona Marín, Lina María

    2014-01-01

    Las anomalías dentales son un grupo de alteraciones morfológicas, que se pueden expresar en la corona o en la raíz dental; aparecen durante el desarrollo de los órganos dentales, se ha establecido que tienen un componente genético y molecular importante. También se han planteado influencias medioambientales, traumáticas y microbiológicas. Las anomalías morfológicas dentarias son comunes, y se presentan con una incidencia de 74,7% según Freer (1998). Los dientes cónicos, en clavija o reducidos...

  12. Pornographie als Metapher

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    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.

  13. Reingeniería de la geometría desconocida de engranajes cónicos con dientes rectos y curvilíneos.

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    G. González Rey

    2008-09-01

    Full Text Available En el trabajo se presenta un procedimiento para dar solución al problema de solución inversa asociado con la determinación de la geometría desconocida del dentado de un engranaje cónico con ejes ortogonales y dientes de altura proporcional en base a cálculos de ingeniería de engranajes y con empleo de mediciones con herramientas de taller. El procedimiento propone un método práctico, con asistencia de un cálculo organizado linealmente y una búsqueda exhaustiva, para obtener los parámetros fundamentales del engranaje que puedan ser utilizados para el cálculo de la capacidad de carga de engranajes cónicos o cuando son “copiados” para realizar la generación de un nuevo engranaje según Normas ISO. El procedimiento de reingeniería, basado en la experiencia de los autores, establece su fundamento en minimizar la diferencia entre parámetros geométricos medidos y calculados, como son los diámetros de crestas de las ruedas, alturas y espesores de los dientes. Los mencionados parámetros pueden ser calculados con una conveniente organización y evaluación de un sistema de fórmulas que involucran las relaciones entre las variables dependientes y variables independientes que se buscan en el proceso de solución al problema inverso de la geometría desconocida, como pueden ser el módulo, los parámetros de la herramienta de generación, los coeficientes de corrección radial y tangencial y el ángulo de la hélice de los dientes.A procedure for the solution of inverse problem to assist gear engineering designers in the cases of the determination of the basic unknown geometry of bevel gear with shaft angle of 90 degrees and standard depthwise tooth taper has been presented. The proposed method can be used as an alternative procedure to determine the unknown bevel gear geometry using conventional measurement tools. The procedure, based on author's experiences, proposes a practical method with assistance of an organized calculation

  14. Prevalência de defeitos de esmalte em indivíduos portadores de fissuras labiopalatinas da Paraíba, Brasil Prevalencia de amelogénesis imperfecta en pacientes con labio y paladar fisurados en Paraíba, Brasil Prevalence of defective amelogenesis in patients with palatoschisis in Paraíba, Brazil

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    Rosa Helena Wanderley Lacerda

    2012-03-01

    los pacientes que asistieron al servicio de ortodoncia de Paraíba, Brasil. Se realizó un estudio transversal y observacional donde se recolectaron datos del examen clínico en 76 pacientes con fisura post foramen, trans foramen incisivo unilateral o bilateral, de ambos sexos y con una edad media de 13,3 años. El examen fue realizado en los dientes incisivos y caninos superiores, por dos examinadores previamente capacitados (kappa= 0,89. Los pacientes incluidos fueron los que asistieron al servicio durante el periodo de enero a junio de 2011, en los que las superficies vestibulares de los dientes que se examinaron permitieron una evaluación clínica. Se excluyeron aquellos con malformaciones y que no habían sido sometidos a cirugía primaria. Los datos fueron sometidos a estadística descriptiva y chi-cuadrado con una significación de 5 %. El sexo masculino representó el 57,9 % y la fisura unilateral izquierda fue de un 40,8 %. En relación con defectos en el esmalte, el diente más afectado fue el incisivo central, mostraron opacidad difusa para un 14,9 %, seguido por la presencia de opacidad limitada para un 13,15 % e hipoplasia con un 10,9 %. Se encontraron diferencias estadísticamente significativas (pThe enamel defects are some of the changes affecting persons with palatoschisis. The aim or present paper was to describe the prevalence of enamel defects with labial and palatine fissure, as well as its distribution by type of fissure in patients came to Orthodontics service of Paraíba, Brazil. A cross-sectional and observational study was conducted to collect data from the postmortem physical examination of 76 patients with palatoschisis through the unilateral and bilateral incisor foramen, of both sexes and a mean age of 13.3 years. The examination was performed in the upper incisor and canines by two examiners previously trained (kappa= 0.89. Patients included were those came to service from January to June, 2011, where the vestibular surfaces of teeth

  15. Diente más afectado por la celulitis facial de origen odontogénico en niños venezolanos

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    Gabriel Zambrano

    2016-07-01

    Full Text Available Objetivo: Determinar la prevalencia de celulitis facial de origen odontogénica e identifi el diente más afectado en niños con diagnóstico de celulitis facial hospitalizados en el Servicio de Infectología Pediátrica del Hospital Universitario de Caracas en el periodo 20062014. Materiales y métodos: se realizó un estudio documental, descriptivo y retrospectivo en niños entre 1-6 años de edad hospitalizados con diagnóstico de celulitis facial odontogénica en el Servicio de Infectología Pediátrica del Hospital Universitario de Caracas en el periodo 2006-2014. Se tomó una muestra no probabilística a conveniencia, la cual quedó conformada por 310 niños quienes cumplieron los criterios de inclusión de la investigación. Los datos se obtuvieron a partir de las historias clínicas de dicho servicio. Se realizó un análisis descriptivo, epidemiológico y comparativo/ analítico para cumplir con los objetivos de la investigación. Resultados: la prevalencia de celulitis facial de origen odontogénico fue de 5,27% con respecto a la muestra total. El segundo molar primario fue el diente más afectado con una frecuencia del 49,5%. CONCLUSIÓN: la prevalencia de celulitis facial de origen odontogénico en comparación con otras infecciones que requieren hospitalización fue baja, el género masculino fue el más afectado, el rango de edad más involucrado con la entidad se ubicó entre los 4 y 6 años. Los dientes primarios fueron los más afectados y el diente más asociado con esta afección fue el segundo molar primario.

  16. Uso de formocresol diluido en dientes temporales

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    Maira Morales de Armas

    1998-04-01

    Full Text Available El formocresol comenzó a usarse en Odontopediatría en 1930 y años más tarde se demostró su efecto citostático sobre la pulpa. Se realizan pulpotomías con formocresol diluido en 25 dientes temporales, de los cuales 14 tenían pulpa vital y 11 no vital; se obtuvo el 92,8 % de resultados positivos en los primeros y el 72,7 % en los segundos, después de 1 año de evolución.Formocresol began to be used in Pedodontics in 1930 and as time went by, its cytostatic effect on pulp was proved. 25 decidous teeth were treated with diluted formocresol pulpotomies, 14 had vital pulp and 11 had non-vital pulp. After one year of evolution good results were obtained in 92.8 % of the first group and in 72.7 % of the second group.

  17. Valoración histológica de la respuesta pulpar y hepática del formocresol y el hueso liofilizado en dientes de rata.

    OpenAIRE

    Alcaina Lorente, Mª Antonia

    2003-01-01

    Son varios los agentes que se han utilizado para las pulpotomías en dientes primarios, siendo el formocresol el más difundido. El objetivo de este estudio fue evaluar la respuesta pulpar en dientes de rata cuando el hueso liofilizado es usado como agente de pulpotomía y analizar los cambios histológicos del tejido hepático. La muestra de este estudio estaba formada por 60 ratas de raza Sprague-Dawley. El tratamiento se realizó en los primeros molares superiores, siendo un total de 120 d...

  18. Diente de un gran dinosaurio terópodo (Allosauroidea de la Formación Villar del Arzobispo (Titónico-Berriasiense de Riodeva (España

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    Alcalá, L.

    2009-06-01

    Full Text Available An isolated theropod tooth from a microconglomerate of the Tithonian-Berriasian Villar del Arzobispo Formation at Riodeva (Aragón, Spain is described. The specimen is remarkably large (apical length: 98.3 mm. The morphology of the tooth is compressed labiolingually, with denticules on the carinae reaching the base in the carina distal but not in the mesial one. These features and their large size allow us to include it in the clade Allosauroidea. Having in mind the dental variability existing among the tooth of the different genera of Allosauroidea we can not assign it to any definite group within this clade.Se describe un diente de dinosaurio terópodo de 98,3 mm de longitud apical hallado en el término municipal de Riodeva (Teruel. El diente ha sido localizado de forma aislada en un nivel de microconglomerados perteneciente a la Formación Villar del Arzobispo de edad Titónico-Berriasiense. La morfología del diente, comprimido labiolingualmente, con las carenas denticuladas que alcanzan la base de la corona distal pero no la mesial, y el tamaño del ejemplar permiten incluirlo dentro del clado Allosauroidea. La variabilidad existente entre los dientes de diferentes géneros de alosauroideos determina que sea prudente no asignarlo a un grupo concreto dentro de este clado.

  19. Tratamento de Classe II, Divisão 1, com ausência congênita de incisivo lateral superior Treatment of Class II Division 1 with congenitally absent maxillary lateral incisor

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    Roberto M. A. Lima Filho

    2004-10-01

    Full Text Available Este relato mostra tratamento Ortodôntico efetuado em paciente portador de Classe II, Divisão 1, de Angle, com sobremordida profunda e agenesia do incisivo lateral superior esquerdo, em que o espaço foi fechado ortodonticamente e o canino ocupou o lugar do incisivo lateral. Os procedimentos adotados possibilitaram a obtenção de estética agradável e relação oclusal normal. A linha mediana não apresentou desvio ao término do tratamento e a discrepância vertical foi devidamente corrigida.This case report demonstrates the orthodontic treatment of a patient who presented a Class II Division 1 malocclusion, deep overbite and congenitally absent maxillary left lateral incisor. The space was closed orthodontically and maxillary cuspid was positioned in the place of the maxillary lateral incisor. The treatment applied resulted in a pleasant esthetics and normal occlusal relationship. The midline was coincident at the end of treatment and vertical discrepancy was properly corrected.

  20. Inducción del cierre apical en el diente con necrosis pulpar y el ápice no formado

    OpenAIRE

    Canalda Sahli, Carlos

    1988-01-01

    Se efectúa una revisión del proceso de apicoformación en dientes con necrosis pulpar y ápice no formado, analizando el mecanismo de cierre apical inducido por el hidróxido de calcio y otras substancias, así como la histopatología del mismo.

  1. Dientes supernumerarios y atresia maxilar: Tratamiento orto-quirúrgico en Odontopediatría. Relato de un caso clínico: 5 años de seguimiento

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    MS Sampaio

    Full Text Available Se describe a los dientes supernumerarios o hiperodoncia como el aumento del número de órganos dentarios comparado con la dentición normal. Todos los dientes supernumerarios deben ser extraídos, respetando el momento ideal para su remoción quirúrgica, evaluando siempre el momento oportuno para intervenir. En el presente trabajo las autoras presentan un caso clínico de una paciente de sexo femenino, que tuvo un seguimiento durante cinco años a partir de los 6 meses de edad asistida en el Curso de Extensión universitaria Bebé Clínica de la Universidad Federal de Río Grande del Sur. Durante sus visitas periódicas de revisión odontológica correspondientes al programa de la Bebé Clínica, se diagnosticó clínicamente la presencia de mordida cruzada anterior, atresia maxilar y radiográficamente la presencia de dos elementos supernumerarios. Frente a este diagnóstico, es necesario un planteamiento multidisciplinario, o sea, orto-quirúrgico para la realización del tratamiento, destacando una vez más, la importancia de la atención odontológica del bebé y el diagnóstico precoz de posibles alteraciones como en el caso clínico en cuestión; la presencia de elementos supernumerarios y maloclusión dentaria

  2. Tratamiento Endodóntico no Instrumentado en dientes deciduos

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    Perona-G

    2014-01-01

    Full Text Available Teniendo en cuenta la complejidad del tratamiento pulpar en una pieza decidua y diversos factores que determinan el éxito clínico como son la anatomía de una pieza decidua, el proceso de reabsorción ya sea de origen fisiológico o por una infección odontogénica, la conducta del paciente, la técnica empleada y la pericia del operador; es de suma importancia que en la práctica odontopediátrica se tenga en cuenta ciertos procedimientos que aseguren la presencia del diente en boca hasta su exfoliación fisiológica, es de esta manera que la Técnica de Endodoncia no Instrumentadas en dientes deciduos es un tema muy importante a tener presente en cuanto a terapia pulpar se refiere. Las pulpectomías no instrumentadas (NIET; termino mal empleado para este procedimiento, ya que la técnica no consiste en realizar una pulpectomía propiamente dicha; en su lugar emplean diversas pastas que tienen por objetivo la desinfección de los conductos radiculares mediante el empleo de sustancias bacteriostáticas y bactericidas y de esta manera permitirán la reparación del los tejidos dañados. El propósito de este artículo fue hacer una revisión de la literatura de todo lo concerniente a Terapia Endodóntica no Instrumentada en dentición decidua. En conclusión se puede decir que dadas las características de la dentición temporal, la cual impide una completa manipulación de los conductos radiculares, el éxito de la pulpectomía depende de la reducción o eliminación de las bacterias no solo dentro del conducto sino también en lugares donde la preparación química y mecánica sea difícil de acceder, en la técnica NIET se utiliza una mezcla de antibióticos para esterilizar el conducto radicular en vez de usar la técnica de instrumentación, las pastas obturadoras asumen un papel fundamental para que la reparación de los elementos dentarios se desenvuelva de acuerdo a los patrones biológicos normales.

  3. Das „neue“ Private. Familie als intime Gefühlsgemeinschaft

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    Regina Harzer

    2006-11-01

    Full Text Available Methodisch versteht sich die Habilitationsschrift als Beitrag zur Rekonstruktion moderner politischer Philosophie. Als zentraler Ansatzpunkt dient das Familienkonzept von Rousseau, seine Schriften werden auf Geschlechterkonstruktionen und bürgerliche Geschlechterordnungen hin untersucht. Grundanliegen der Studie ist es, Bürgerlichkeit unter ihrem zentralen Aspekt des Privaten zu betrachten und in den Kontext moderner kontraktualistischer Philosophie zu stellen. Die Autorin vertritt die Ausgangsthese, Rousseau müsse eine „Schlüsselstellung“ (S. 9 in der Geschichte der bürgerlichen Geschlechter- und Familienordnung zugesprochen werden. Durch ihn sei die Trennung des Privaten vom Öffentlichen eingeleitet und festgeschrieben worden.

  4. Reingeniería de la geometría desconocida de engranajes cónicos con dientes rectos y curvilíneos. // Determination of the unknown geometry of straight and spiral bevel gears by means of inverse engineering.

    OpenAIRE

    G. González Rey; S. A. Marrero Osorio

    2008-01-01

    En el trabajo se presenta un procedimiento para dar solución al problema de solución inversa asociado con la determinaciónde la geometría desconocida del dentado de un engranaje cónico con ejes ortogonales y dientes de altura proporcional enbase a cálculos de ingeniería de engranajes y con empleo de mediciones con herramientas de taller. El procedimientopropone un método práctico, con asistencia de un cálculo organizado linealmente y una búsqueda exhaustiva, para obtenerlos parámetros fundame...

  5. Primera cita de cocodrilos zifodontos en el Cenozoico de Asturias: Royo Gómez y los supuestos dientes de dinosaurio del Eoceno de Llamaquique

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    Pereda Suberbiola, X.

    2012-12-01

    Full Text Available In 1928, José Royo Gómez mentioned the find of “two teeth similar to those of theropod dinosaurs from the Secondary” in the Eocene of Llamaquique (Oviedo Basin, Asturias. Royo Gómez was aware of the interest of the discovery, “because they would be the youngest remains found of these gigantic reptiles”. According to the hitherto unpublished documents preserved in the Archives of the Museo Nacional de Ciencias Naturales in Madrid, Royo Gómez photographed five teeth from Llamaquique in April 1932, which he regarded as belonging to theropods. The whereabouts of this material is currently unknown. However, the revision of the Llamaquique collection in the above mentioned museum has allowed to recover one labiolingually compressed and serrated tooth (ziphodont condition. We reject here that the tooth belongs to a theropod, and we assign it to a Mesoeucrocodylia indet. This is the first mention of the discovery of ziphodont crocodyliforms in the Paleogene of Asturias.

    En 1928, José Royo Gómez informó del hallazgo de “dos dientes idénticos a los de los Dinosaurios terópodos del Secundario” en el Eoceno de Llamaquique (Cuenca de Oviedo, Asturias. Royo Gómez era consciente del interés de este descubrimiento, “pues serían los restos más modernos que se conocerían de estos gigantescos reptiles”. Según la documentación conservada en el Archivo del Museo Nacional de Ciencias Naturales en Madrid, hasta ahora inédita, Royo Gómez fotografió en abril de 1932 cinco dientes de Llamaquique que él consideraba pertenecientes a terópodos. Este material se encuentra actualmente en paradero desconocido. No obstante, la revisión de la colección paleontológica de Llamaquique en el mencionado museo ha permitido recuperar un diente comprimido lateralmente y provisto de carenas denticuladas (condición zifodonta. Se descarta que el diente pertenezca a un terópodo, asignándose a un Mesoeucrocodylia indeterminado. Se trata de la

  6. Combinación quirúrgica: una necesidad en Odontopediatría

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    Roberta Dias dos Santos

    2017-07-01

    Full Text Available Introducción: El Mesiodens es un diente supernumerario que se forma en la línea media entre los incisivos centrales superiores, más frecuentemente en la dentición permanente y en pacientes de sexo masculino. Su etiología es bastante desconocida, pero la hiperactividad de la lámina dentaria es la teoría más aceptada. Se presenta asociado a otras complicaciones, como el diastema interincisivo, que puede también estar asociado a la inserción anormal del frenillo labial superior, provocando alteraciones en la estética dentaria. El objetivo de este trabajo fue comunicar sobre un caso clínico de exodoncia de un mesiodens y de la resección del frenillo labial superior en un solo procedimiento quirúrgico, con seguimiento del cierre fisiológico del diastema luego de 1 año. Reporte de caso: El presente trabajo reporta el caso de un niño, de 11 años de edad, que ingresó a la clínica-escuela de Odontopediatría de la Facultad Independiente del Nordeste acompañado por su madre, con queja estética de separación dental. Después de la anamnesis, examen clínico y radiográfico se diagnosticó la presencia de mesiodens e inserción anormal del frenillo labial superior. Se seleccionó como tratamiento una técnica quirúrgica combinada de exodoncia del mesiodens y frenectomía en una misma sesión, con seguimiento de un año y observación del cierre progresivo del diastema entre los incisivos. Conclusión: El diagnóstico correcto de dientes supernumerarios y anormalidades del frenillo es fundamental, a través de un buen examen clínico y radiográfico para la realización del tratamiento individualizado, siendo exitoso en este caso la combinación quirúrgica.

  7. Valoración del tratamiento de la pulpotomía con MTA en dientes temporales vitales

    OpenAIRE

    Biedma Perea, María

    2014-01-01

    Texto completo descargado desde Teseo I. INTRODUCCIÓN La pérdida prematura de la pieza temporal puede conducir a maloclusiones, problemas estéticos, fonéticos y funcionales como hábitos, que pueden ser transitorios o permanentes.1 La pulpotomía es uno de los recursos para poder conservar los dientes deciduos, así estos actúan como mantenedores de espacios naturales hasta la erupción de la dentición permanente.2,3,4 El uso de materiales dentales como apósitos pulpares en el tratamiento de p...

  8. Prevalencia de dientes supernumerarios en pacientes con labio y paladar hendido mediante el análisis de ortopantomografías

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    María del Carmen Navas-Aparicio

    2017-07-01

    Conclusiones: El diente supernumerario es una anomalía que se presenta en los pacientes con labio y paladar hendido, por lo que es pertinente el buen diagnóstico clínico y radiográfico para determinar su presencia, y así escoger la más apropiada opción de tratamiento según las necesidades del caso.

  9. Dientes estabilizados con implantes endodónticos intraóseos como pilares de prótesis

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    Soraya Emilia Almagro Urrutia

    2003-08-01

    Full Text Available Se muestran 2 casos clínicos de pacientes que presentaban dientes con movilidad grado III, a los cuales se les realizó la técnica del implante endodóntico intraóseo, que consiste en la colocación de un perno o implante de cromo cobalto molibdeno a través del conducto radicular hasta pleno tejido óseo, con el objetivo de prolongar su longitud radicular. Los casos se evaluaron a los 15 y 45 días posimplantación y evolucionaron satisfactoriamente, por lo que se decidió comenzar el tratamiento protésico utilizando precisamente como pilares los dientes implantados. Ambos casos fueron evaluados a los 45 días después de la rehabilitación y cada 90 días hasta la fecha. Su evolución fue satisfactoria y no presentaron ninguna patología clínica y radiográfica.2 clinical cases of patients that presented tooth with degree III mobility, in which the technique of intraosteal endodontic implant, consisting in the placement of a dowel or implant of chrome-cobalt molybdenum through the radicular duct to full bone tissue, was applied aimed at prolonging their radicular length. The cases were evaluated 15 and 45 days after the implantation. As their evolution was satisfactory it was decided to begin the prosthetic treatment by using precisely the implanted tooth as abutements. Both cases were evaluated 45 days after the rehabilitation and every 90 days up to date. Their evolution was good and there were no clinical or radiographic pathologies.

  10. Má oclusão Classe I de Angle com agenesia de incisivos laterais Angle Class I malocclusion and agenesis of lateral incisors

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    Fernanda Catharino Menezes Franco

    2011-08-01

    Full Text Available O planejamento ortodôntico de pacientes com agenesia de incisivos laterais envolve considerações estéticas e funcionais de grande relevância para um resultado clínico satisfatório. Tanto o fechamento dos espaços correspondentes aos dentes ausentes quanto sua abertura ou manutenção oferecem vantagens e desvantagens que devem ser avaliadas de acordo com as características individuais do paciente. Fatores importantes que influenciam o planejamento são o padrão esquelético, o tipo de má oclusão e a coloração e forma dos caninos, dentre outros. Neste artigo, teve-se como objetivo relatar o tratamento de uma paciente com má oclusão Classe I de Angle, agenesia de incisivos laterais, sobressaliência e sobremordida diminuídas, tendência à mordida aberta e mordida cruzada.A abordagem clínica foi realizada com expansão maxilar, seguida de fechamento dos espaços, com auxílio de ancoragem esquelética extrabucal. Esse caso foi apresentado à diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO, como parte dos requisitos para a obtenção do título de Diplomado pelo BBO.Orthodontic planning for patients with agenesis of lateral incisors should include extremely relevant esthetic and functional considerations so that a satisfactory clinical result is achieved. Both space closure and space opening and maintenance have advantages and disadvantages that should be evaluated according to the patient's individual characteristics. Some of the important factors that affect planning are the skeletal pattern, the type of malocclusion and the color and shape of canines. This study reports on the treatment of a patients with Class I malocclusion and agenesis of lateral incisors, overjet, decreased overbite, and a tendency to open bite and crossbite. The clinical approach included palatal expansion followed by space closure using extraoral anchorage. This case was presented to the Committee of the Brazilian Board of Orthodontics

  11. Reingeniería de la geometría desconocida de engranajes cónicos con dientes rectos y curvilíneos. // Determination of the unknown geometry of straight and spiral bevel gears by means of inverse engineering.

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    G. González Rey

    2008-09-01

    Full Text Available En el trabajo se presenta un procedimiento para dar solución al problema de solución inversa asociado con la determinaciónde la geometría desconocida del dentado de un engranaje cónico con ejes ortogonales y dientes de altura proporcional enbase a cálculos de ingeniería de engranajes y con empleo de mediciones con herramientas de taller. El procedimientopropone un método práctico, con asistencia de un cálculo organizado linealmente y una búsqueda exhaustiva, para obtenerlos parámetros fundamentales del engranaje que puedan ser utilizados para el cálculo de la capacidad de carga deengranajes cónicos o cuando son “copiados” para realizar la generación de un nuevo engranaje según Normas ISO. Elprocedimiento de reingeniería, basado en la experiencia de los autores, establece su fundamento en minimizar la diferenciaentre parámetros geométricos medidos y calculados, como son los diámetros de crestas de las ruedas, alturas y espesores delos dientes. Los mencionados parámetros pueden ser calculados con una conveniente organización y evaluación de unsistema de fórmulas que involucran las relaciones entre las variables dependientes y variables independientes que se buscanen el proceso de solución al problema inverso de la geometría desconocida, como pueden ser el módulo, los parámetros dela herramienta de generación, los coeficientes de corrección radial y tangencial y el ángulo de la hélice de los dientes.Palabras claves: Engranaje cónico, ingeniería inversa, geometría de engranaje.______________________________________________________________________________AbstractA procedure for the solution of inverse problem to assist gear engineering designers in the cases of the determination ofthe basic unknown geometry of bevel gear with shaft angle of 90 degrees and standard depthwise tooth taper has beenpresented. The proposed method can be used as an alternative procedure to determine the unknown bevel gear geometryusing

  12. Resistencia de dientes restaurados con postes prefabricados ante cargas de máxima intercuspidación, masticación y bruxismo

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    Santiago Correa Vélez

    2013-03-01

    Full Text Available Objetivo: determinar por el método de los elementos finitos la resistencia de dientes restaurados con postes prefabricados ante cargas estáticas de máxima intercuspidación y cargas cíclicas de masticación y bruxismo y analizar el efecto de la pérdida periodontal en la resistencia de las restauraciones. Métodos: se realizó una investigación in vitro mediante el método de los elementos finitos de dientes con pérdida periodontal, rehabilitados con postes prefabricados en fibra de vidrio, carbono y titanio. Los dientes fueron reconstruidos a partir de imágenes tomográficas de un paciente periodontalmente sano. Resultados: se muestra que ante cargas estáticas las rehabilitaciones no presentan tendencia a la falla, independientemente del material del poste o del grado de pérdida periodontal. En el caso de bruxismo y pérdida periodontal de 4 mm, la dentina presenta una durabilidad de 60 000 ciclos independiente del material del poste. Para cargas de masticación y periodonto sano, la falla en la dentina ocurre a los 100 000 ciclos con poste en titanio, 200 000 ciclos con poste en fibra de carbono y 1 100 000 ciclos con poste en fibra de vidrio. Para una pérdida periodontal de 2 mm la durabilidad de la dentina se reduce a 4 000 ciclos con poste en titanio, 5 000 ciclos con poste en fibra de carbono y 7 000 ciclos con poste en fibra de vidrio. Para pérdida periodontal de 4 mm, la durabilidad de la dentina se estima en 1 000 ciclos, independientemente del material del poste utilizado. Conclusiones: ante carga estática de máxima intercuspidación las rehabilitaciones con postes prefabricados en fibra de vidrio, carbono y titanio no presentan tendencia a la falla, independientemente del grado de pérdida periodontal. Ante cargas cíclicas, los postes prefabricados presentan una vida útil infinita, y es la dentina la estructura más afectada ante dichos eventos.

  13. Modelo matemático y procedimiento para la generación gráfica de los contornos de dientes de engranajes cilíndricos. // A mathematical model and procedure for graphic generation of tooth flanks of cylindrical gear.

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    G. González Rey

    2006-01-01

    Full Text Available El presente trabajo de desarrollo está dirigido a brindar un modelo matemático que permita el perfeccionamiento del cálculo dela capacidad de carga de los engranajes cilíndricos con empleo del método de los elementos finitos. El procedimiento estábasado en un modelo matemático del lugar geométrico de los puntos del contorno de los dientes en coordenadas polares. Labase del procedimiento considera una geometría precisa de los flancos de los dientes y toma en cuenta la influencia de laherramienta de generación de los flancos y la posibilidad de modificación del perfil del diente, con el distintivo interés yactualidad de potenciar el perfeccionamiento de la evaluación de los esfuerzos en los dientes de ruedas dentadas en lasinvestigaciones asociadas con la valoración de la capacidad de carga de los engranajes cilíndricos.Palabras claves : Engranajes ci l índri cos , f lanco del diente , modelo matemát ico, método de elementos f ini tos .__________________________________________________________________________Abs tract .A mathematical model based developed in coordinated polar and a computational procedure for graphic generation of tooth flanks inexternal parallel-axis cylindrical involute gears are exposed. The mentioned model and procedure are able to consider the effect inthe tooth gear geometry of the addendum modification coefficient and the rack shaped tool used in the cutting of gear. Additionally,the results are useful for the improvement of the gear tooth model and formulations for the load capacity calculation of cylindricalgears by means of the method of finite elements. For the determination of the calculation procedures based on the mathematicalmodels was established using the technique of dichromatic graphs.Key words : Ext e rnal pa ral l e l -axi s cyl indri cal involute g ear s , tooth f lanks , mathemat i cal model ,FEM.

  14. Traumatismos dentales en niños de 12 a 14 años en el municipio San José de las Lajas Traumatic dental injures in 12-14 years-old children from San José de las Lajas municipality

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    Jesús Gallego Rodríguez

    2004-08-01

    Full Text Available Se realizó un estudio epidemiológico retrospectivo en 1 280 alumnos, 679 varones y 601 hembras de las secundarias básicas del municipio San José de las Lajas, provincia de La Habana, cuyas edades oscilaron entre los 12 y 14 años de edad, para conocer los tipos, la prevalencia y la etiología de los traumatismos dentarios en los dientes antero-superiores. Se utilizó la clasificación de Andreassen para determinar los tipos de fracturas coronarias. La fractura simple de esmalte predominó, con el 63,1 %, la principal causa de traumatismos dentarios se debió a caídas (75,3 % seguidas de choques con personas u objetos inanimados (10,3 %; los varones sufrieron más lesiones en los dientes que las hembras (63,2 y 36,7 %, respectivamente. El diente más afectado fue el incisivo central derecho (47,4 %. La mayoría de los alumnos (77,1 % no concurrieron a las clínicas estomatológicas para recibir tratamiento.A prospective cross-sectional study of 1280 students (679 boys and 601 girls aged 12-14 years-old from high schools located in San José de las Lajas municipality, La Habana province was conducted. The objective was to find out types, prevalence and etiology of traumatic dental injures in upper anterior teeth. Andreassen´s classification was used to determine the type of dental fracture. Simple enamel fracture predominated (63.1%. The main cause of dental injures was fall (75.3% followed by collisions with persons or objects (10,3%. Boys experienced more injures than girls (63,2 vs. 36,7% did. The most affected tooth was right central incisor (47,4%. The majority of students (77,1% that suffered dental injures did not go to a dental clinic to be treated.

  15. Endodoncia regenerativa: utilización de fibrina rica en plaquetas autóloga en dientes permanentes vitales con patología pulpar. Revisión narrativa de la literatura*

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    Tatiana Ramírez Giraldo

    2014-01-01

    Full Text Available Actualmente una de las mayores controversias en el tratamiento de dientes permanentes con diagnóstico de pulpitis está en la decisión de realizar una Terapia Pulpar Vital (TPV o un tratamiento convencional de conductos. Diferentes estudios han reportado que se pueden obtener resultados previsibles mediante la realización de una TPV. El éxito del tratamiento dependerá de una adecuada comprensión de la  biología pulpar, un estricto protocolo de tratamiento y una adecuada selección del caso. Con este fin, diferentes materiales han sido sugeridos. Recientemente se ha utilizado la Fibrina Rica en Plaquetas, biomaterial que cumple con propiedades biológicas para lograr una mayor rapidez y adecuada cicatrizacion del tejido. Es necesario desarrollar tratamientos dirigidos a preservar la vitalidad de la pulpa, evitando recurrir como primera opción al tratamiento convencional de conductos, teniendo como objetivo conservar o regenerar el complejo dentino pulpar.

  16. Endodoncia regenerativa: utilización de fibrina rica en plaquetas autóloga en dientes permanentes vitales con patología pulpar. Revisión narrativa de la literatura*

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    Tatiana Ramírez Giraldo

    2014-07-01

    Full Text Available Actualmente una de las mayores controversias en el tratamiento de dientes permanentes con diagnóstico de pulpitis está en la decisión de realizar una Terapia Pulpar Vital (TPV o un tratamiento convencional de conductos. Diferentes estudios han reportado que se pueden obtener resultados previsibles mediante la realización de una TPV. El éxito del tratamiento dependerá de una adecuada comprensión de la  biología pulpar, un estricto protocolo de tratamiento y una adecuada selección del caso. Con este fin, diferentes materiales han sido sugeridos. Recientemente se ha utilizado la Fibrina Rica en Plaquetas, biomaterial que cumple con propiedades biológicas para lograr una mayor rapidez y adecuada cicatrizacion del tejido. Es necesario desarrollar tratamientos dirigidos a preservar la vitalidad de la pulpa, evitando recurrir como primera opción al tratamiento convencional de conductos, teniendo como objetivo conservar o regenerar el complejo dentino pulpar.

  17. Diente más afectado por la celulitis facial de origen odontogénico en niños venezolanos

    OpenAIRE

    Gabriel Zambrano; Rosa Rondón; María Elena Guerra

    2016-01-01

    Objetivo: Determinar la prevalencia de celulitis facial de origen odontogénica e identifi el diente más afectado en niños con diagnóstico de celulitis facial hospitalizados en el Servicio de Infectología Pediátrica del Hospital Universitario de Caracas en el periodo 20062014. Materiales y métodos: se realizó un estudio documental, descriptivo y retrospectivo en niños entre 1-6 años de edad hospitalizados con diagnóstico de celulitis facial odontogénica en el Servicio de Infectología Pediátric...

  18. Implante transalveolar en sustitución de una corona espiga de pronóstico dudoso*

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    Josefina Fajardo Puig

    Full Text Available La sustitución de los dientes perdidos en la región estética presenta un complejo desafío debido a la dificultad en la reforma de la apariencia natural y de la anatomía papilar. Se Presenta un caso clínico donde se sustituyó un diente con corona espiga de pronóstico dudoso, por un implante inmediato Avanza. Se trata de una paciente de 24 años de edad atendida en la consulta multidisciplinaria de Implantología de la Clínica Docente de Prótesis de Marianao. Tenía una corona espiga en el incisivo central superior derecho, con cambio de coloración que le afectaba su estética. Además se le caía constantemente y estaba ligeramente inflamada por vestibular, lo cual le producía dolor. Después de una evaluación multidisciplinaria y el consentimiento de la paciente, se procede a la retirada de la corona espiga y exodoncia de la raíz del 11 mediante la técnica de colgajo. Inmediatamente se colocó el implante Avanza y se rehabilitó con una prótesis parcial acrílica removible por razones estéticas. Con este tratamiento, la paciente mantuvo el contorno de los tejidos blandos y la altura ósea de la zona intervenida, necesarios para alcanzar excelentes resultados estéticos.

  19. Efeitos dos fios de nivelamento de níquel-titânio e de aço inoxidável na posição dos incisivos inferiores Effects of nickel-titanium and stainless steel leveling wires on the position of mandibular incisors

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    Ricardo Moresca

    2011-10-01

    Full Text Available OBJETIVO: estudar os efeitos do nivelamento realizado com fios de NiTi termoativado e de aço inoxidável, avaliando-se as possíveis alterações na posição dos incisivos inferiores, em casos com extrações, correlacionando com o tempo de tratamento. MÉTODOS: a amostra foi composta de 36 indivíduos, de ambos os sexos, leucodermas brasileiros, com idade média inicial de 15 anos e 5 meses, portadores de más oclusões de Classes I e II, distribuídos em dois grupos. No Grupo 1 (n=17, o nivelamento foi realizado com a sequência 1, utilizando-se três fios - 0,016" e 0,019"x0,025" de NiTi termoativado, e 0,019"x0,025" de aço inoxidável. No Grupo 2 (n=19, foi testada a sequência 2, na qual foram utilizados apenas fios de aço inoxidável (0,014"; 0,016"; 0,018"; 0,020" e 0,019"x0,025" com torque passivo nos incisivos inferiores. Os dados foram coletados utilizando-se o método cefalométrico computadorizado e comparados pelo teste t de Student com o nível de significância de 5%. RESULTADOS: no Grupo 1, os incisivos inferiores inclinaram-se para lingual, com movimento significativo apenas da coroa (1,6mm. No Grupo 2, os incisivos inferiores permaneceram estáveis. Não houve alteração vertical em nenhum dos grupos. CONCLUSÕES: a sequência 2 proporcionou um melhor controle dos incisivos inferiores, não alterando suas posições iniciais, enquanto a sequência 1 permitiu a expressão do torque da prescrição utilizada, levando a uma inclinação lingual desses dentes. O tempo de tratamento foi menor utilizando-se a sequência 1. As variações biomecânicas estudadas apresentaram vantagens e desvantagens que devem ser conhecidas e ponderadas pelo ortodontista no planejamento do caso.OBJECTIVE: To study the effects of the leveling phase performed with heat activated NiTi and stainless steel archwires evaluating the possible changes in lower incisors position in extraction cases, as well as its correlation with treatment time. METHODS

  20. Normal microbiota of the perialveolar region of incisors of rats Microbiota normal da região perialveolar de incisivos em ratos

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    F.R.G. Araújo

    2007-12-01

    Full Text Available Identificou-se a microbiota normal da região peri-alveolar de incisivos em 72 ratos Wistar, com 70-90 dias de idade e 280-330g de peso. As bactérias foram coletadas com suabes embebidos em solução salina. Do material depositado em tubo contendo 460µl de Brain Heart Infusion e diluído em 1:10, retirou-se 1µl para semeadura em placas de Petri. O crescimento médio foi 1,4x10(6 ± 2,6x10(5UFC/ml. Segundo a ordem das freqüências, as bactérias encontradas foram: Bacillus sp., Staphylococcus aureus, Streptococcus viridans, Corynebacterium sp., Staphylococcus coagulase negativa, Enterococcus sp., Staphylococcus saprophyticcus, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae e Serratia liquefaciens. De todas as bactérias isoladas, as Gram-positivas e as Gram-negativas compreenderam 91,2% e 8,8%, respectivamente. Dentre as Gram-positivas, a mais freqüente foi Bacillus sp.(31,2% e a menos, Staphylococcus saprophyticcus (3,0%. Quanto às bactérias Gram-negativas, a mais encontrada foi Escherichia coli (50,1% e a menos, Serratia liquefaciens (6,2%.

  1. Cánula rígida, alternativa en el tratamiento estético-funcional de la apicoformación por fractura complicada de corona

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    Javier Alvarez Rodríguez

    Full Text Available Las edades más afectadas, por la presencia de fracturas complicadas de corona, son la niñez y la adolescencia. En la mayoría de los pacientes se afectan los incisivos centrales superiores permanentes de incompleta formación apical. Esto implica una disminución de las capacidades de masticación, dicción y trae consigo implicaciones psicológicas en la adolescencia. El tratamiento consiste en la aplicación de una técnica de apicoformación que dificulta lograr al unísono la resolución de la afección estética. Nuestro propósito es describir un caso de apicoformación en incisivo central superior izquierdo, con cementación de cánula rígida, conformación de muñón y restauración estético-funcional definitiva. Un paciente de 8 años, masculino acude a consulta tras sufrir traumatismo dentoalveolar consistente en fractura complicada de corona. Los rayos X muestran ligero ensanchamiento periodontal y ápice inmaduro. Se le aplicó anestesia local, se realizó la extirpación pulpar total del diente afectado, y se colocó medicamento intraconducto. La culminación del tratamiento de restauración total coronaria se realizó con la cementación con ionómero de vidrio tipo II de una cánula rígida No. 22 hasta las dos terceras partes de la longitud de trabajo; alrededor de esta se conformó un muñón y corona de nano composite híbrido fotopolimerizable. Se controló evolución cada 24 días, durante tres meses para comprobar el estado de maduración apical. La cementación de la cánula rígida, consituye una alternativa para el tratamiento funcional de la apicoformación por fractura complicada de corona. Supone una rápida recuperación de las funciones bucodentales y psicológico-sociales integrales del paciente.

  2. Revascularización pulpar en dientes permanentes jóvenes con ápice abierto y pulpa necrótica: revisión bibliográfica

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    Molina Adame, Nuria

    2016-01-01

    INTRODUCCIÓN: La revascularización pulpar es un tratamiento regenerativo para tratar dientes inmaduros con pulpa necrótica por caries o traumatismos que, a diferencia de la apexificación y el uso de barreras apicales artificiales, permite la continuación del desarrollo radicular. Esta revisión tiene por objeto exponer el procedimiento y principios básicos de la revascularización así como ver las posibles ventajas e inconvenientes que presenta. MATERIAL Y MÉTODO: se realiza l...

  3. Estudo cefalometrico da posição dos incisivos superiores em individuos dotados de oclusão normal em relação a uma perpendicular a linha SN que passa pelo ponto A

    OpenAIRE

    Zeferino Yutaca Miyamura

    1997-01-01

    Resumo: Realizou-se um estudo cefalométrico radiográfico da posição dos incisivos superiores em relação a uma linha auxiliar perpendicular à linha Sela-Násio, que passa pelo ponto A. Utilizaram-se 60 indivíduos brasileiros, leucodermas, de descendência européia. Trinta indivíduos eram do sexo masculino, com idade variando de 14 anos e 1 mês a 30 anos, com média de 18 anos e 9 meses e 30 indivíduos do sexo feminino, com idade variando de 13 anos a 29 anos e 5 meses, sendo a média de 19 anos e ...

  4. El uso de dientes artificiales de acrílico y porcelana como factor de reabsorción de procesos residuales en pacientes desdentados totales. Estudio transversal

    OpenAIRE

    Sánchez Rubio Carrillo, Raúl Armando; Universidad Autónoma de Baja California, Mexicali, México; Verdugo Díaz, Roberto de Jesús; Universidad Autónoma de Baja California, Mexicali, México; Sánchez Rubio Carrillo, Ricardo Manuel; Universidad Autónoma de Baja California, Mexicali, México; Barreras Serrano, Alberto; Universidad Autónoma de Baja California, Mexicali, México; Vélez Gutiérrez, Jesús Alfonso; Universidad Autónoma de Baja California, Mexicali, México

    2011-01-01

    Objetivo: valorar el efecto de dientes de porcelana y acrílico en los procesos residuales en pacientes desdentados totales. Métodos: se realizó un estudio transversal en 193 pacientes desdentados, quienes usaban dentaduras desde hacía más de cinco años y en quienes se analizó la altura de los procesos residuales. Los pacientes se clasificaron por medio de los criterios de Atwood. La significancia estadística de las hallazgos con los diferentes materiales fueron analizadas con la prueba χ2. Re...

  5. Game of Thrones – Fernsehserien als Artikulation gesellschaftlich-unbewusster Phantasien

    Directory of Open Access Journals (Sweden)

    Gerald Poscheschnik

    2016-08-01

    Full Text Available Kulturelle Produkte, wie z.B. Fernsehserien, lassen sich als Artikulationsformen gesellschaftspolitischer Phantasien verstehen, die bewusste und unbewusste Elemente in sich bergen. Game of Thrones, ein furioses Fantasy-Mittelalterspektakel, aufgeladen mit Gewalt und Sex, scheint auf den ersten Blick nur wenig tagesaktuelle Bezüge aufzuweisen. Eine psychoanalytische Untersuchung, die die Serie ihres manifesten Gewands entkleidet, legt wesentliche Elemente und ihre Relationen frei, die frappante Parallelen zu rezenten gesellschaftspolitischen Phantasien offenlegen. Die Verhältnisse am fiktiven Kontinent Westeros bieten sich als Zeitdiagnose einer niedergehenden Kultur an, deren Potentaten völlig von einem Ränkespiel um Macht und Einfluss absorbiert sind und ihre Wahrnehmung all dem verweigern, was nicht ihrem eigenen Machterhalt dient. Der durch eine Mauer abgeschottete Norden des Landes kann als Deponie für die verdrängten Nebenwirkungen des eigenen Treibens, wie z.B. Umweltzerstörung und menschliches Elend, verstanden werden, deren deletäre Wirkung letztlich die eigene Existenz bedroht. Der ferne Kontinent Essos repräsentiert die Hoffnung, es könnte noch eine Wende oder Alternative entstehen. Die Medienpädagogik kann einen bildungstheoretischen Beitrag zum Verständnis moderner Fernsehserien leisten, benötigt dazu aber auch den interdisziplinären Austausch.

  6. Efecto de las células madre mesenquimales del tejido adiposo en la reparación del hueso alveolar después de la extracción dental

    OpenAIRE

    Moreno Quispe, Luz Arelis

    2015-01-01

    En España la media de dientes ausentes en la población de 35-44 años es de 1.40 y en la población de 65-74 años con al menos 21 dientes funcionales asciende a 44.3%, siendo un problema generalizado, inclusive en muchos países de Latinoamérica como Perú, donde cerca de medio millón de dientes se extraen anualmente (Llodra, 2012) La resorción ósea alveolar tiene varias causas: la extracción dental, trauma, periodontitis moderada a severa y fuerza continúa en el tratamiento ortodóntico. Todo ...

  7. Anesthetic success of 1.8ml lidocaine 2% for mandibular tooth extraction. A pilot study

    OpenAIRE

    Pedro Aravena; Nicol Bustos; Andrea Cerón; Viviana Castillo; Claudio González

    2013-01-01

    RESUMEN Objetivo: Determinar el efecto anestésico de un cartucho de 1,8ml de anestesia lidocaína al 2% con epinefrina 1:100.000 en la técnica troncular al nervio alveolar inferior (NAI) para la exodoncia de dientes mandibulares. Material y método: Estudio piloto de carácter analítico. Participaron pacientes voluntarios del servicio Urgencia Dental de Valdivia-Chile con indicación de exodoncia en dientes mandibulares entre Mayo y Julio del año 2010. La técnica anestésica fue realizada por un ...

  8. Efecto de dos agentes remineralizantes en lesiones de mancha blanca: Estudio in Vitro

    Directory of Open Access Journals (Sweden)

    Grace Maribel Chicaiza Naranjo

    2016-07-01

    Full Text Available La caries dental continúa siendo la enfermedad con mayor prevalencia en el mundo, es importante diagnosticarla y tratarla desde su estadio inicial de mancha blanca ya que es una lesión reversible. La aparición de nuevos materiales como el fosfopéptido de caseína- estabilizado de fosfato de calcio amorfo (Recaldent para remineralizar las manchas blancas nos brindan más opciones terapéuticas en Odontopediatria. Objetivo: Evaluar in-vitro la remineralización de la mancha blanca a partir de la aplicación de las pastas dentales a base de Recaldent: Mi Paste y Mi Paste Plus en dientes temporales. Materiales y métodos: Fueron utilizados 30 dientes temporales sanos obtenidos por movilidad fisiológica, divididos en Grupo A 15 dientes, Grupo B 15 dientes, en ambos grupos se generó la mancha blanca con un agente desmineralizante, para la remineralización  al grupo A se le aplicó Mi Paste, al grupo B Mi Paste Plus, se evaluó el grado de desmineralización y remineralización mediante un láser, Diagnodent, después de 10 días de la aplicación de las pastas dentales. Resultados: Se demostró que en ambos grupos existió remineralización de la mancha blanca, 14.73 grados de fluorescencia con Mi Paste y 15.67 grados con Mi Paste Plus, siendo mayor el grupo B. Conclusión: Concluyendo que, si existe remineralización de la mancha blanca a partir de la aplicación de pasta dental, Mi Paste y Mi Paste Plus con derivados de la caseína (Recaldent en dientes temporales, estudio in vitro. Logrando mejores resultados al utilizar Mi Paste Plus. 

  9. Kino filmų titrai kaip kalbų mokymosi priemonė. Untertitel als Mittel zum Fremdsprachenerwerb

    Directory of Open Access Journals (Sweden)

    Alina Baravykaitė

    2007-01-01

    Full Text Available Das in den letzten Jahren spürbare Bestreben der litauischen Gesetzgeber, Untertitelung von Fernsehfilmen zwecks Fremdsprachenerwerb gesetzlich anzuordnen, löste eine Auseinandersetzung in der Öffentlichkeit aus, die sich in der Presse sowie im Internet widerspiegelt und als Anstoß zum vorliegenden Beitrag dient. Diese Arbeit stellt den Versuch dar, die Möglichkeiten und Grenzen der Untertitelung als eines Mittels zum Fremdsprachenerwerb zu untersuchen. Auf Grund der fehlenden wissenschaftlichen Forschungen in diesem Bereich sollen dabei empirische Betrachtungen und die vergleichende Textanalyse von Original und Übersetzung als Hilfe dienen. Auch wenn die Relevanz der Untertitelung für den Fremdsprachenerwerb nicht bestreitbar ist, ist sie aber zugleich nicht zu überschätzen: Durch die lediglich für diese Form der audiovisuellen Übersetzung charakteristischen Merkmale (kurze Einblendezeit, kondensierte Sprache und begrenzte Übertragungsmöglichkeiten von Realia-Begriffen, Phraseologismen, Intertextualismen, dem Wortspiel etc. bleiben dem Zuschauer oft sprachliche Stilmittel vorenthalten und der in allen Übersetzungsbereichen vorkommende unausweichliche Sinn- und Wirkungsverlust des Originals wird erheblich verstärkt. Anbetracht der erwähnten Aspekte und der häufigen fehlerhaften Übersetzungen sollen Untertitel nur als Hilfsmittel beim Fremdsprachenerwerb angewendet werden, wobei herkömmliche Lehr- und Lernstrategien von Fremdsprachen in den Vordergrund treten müssen.

  10. A fully variable, piezo-actuated research injection system as a tool in diesel engine combustion process development; Ein vollvariables, piezoaktuiertes Foschungs-Einspritzsystem als Werkzeug in der dieselmotorischen Brennverfahrensentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, S.; Stegemann, J.; Seebode, J.; Merker, G.P. [Hannover Univ. (Germany). Inst. fuer Technische Verbrennung

    2004-07-01

    The injection process is a central optimisation approach for low-cost, low-emission diesel engines. An injection system is presented which comprises a pressure modulator and a research injector with piezo-actuated direct actuation of the nozzle. The high flexibility of the system enables systematic investigations of different combustion processes. (orig.) [German] Die Einspritzverlaufsformung als Mittel zur Minimierung von Rohemissionen bleibt auch im heutigen, von Diskussionen und Partikelfilter und Entstickungstechnologien gepraegten Umfeld ein zentraler Optimierungsansatz fuer kostenguenstige und emissionsarme Dieselmotoren. Das hier vorgestellte Einspritzsystem, bestehend aus einer Druckmodulationseinheit und einem Forschungsinjektor mit piezogesteuerter Direktansteuerung der Duesennadel, dient zur Potenzialanalyse einer freien Einspritzverlaufsformung als Mittel zur innermotorischen Brennverfahrensoptimierung. Dank der hohen Flexibilitaet des Systems sind systematische Untersuchungen in Bezug auf unterschiedliche Brennverfahren moeglich. (orig.)

  11. Importancia del tratamiento ortodóncico en la efectividad de los implantes dentales

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Díaz Acosta

    Full Text Available Los implantes osteointegrados permite recuperar de forma fija y cómoda todas las funciones del diente perdido. El objetivo de esta presentación es demostrar los beneficios de realizar tratamientos ortodóncico previos a la colocación de implantes dentales en pacientes edentes. Un paciente de 21 años acudió a consulta de implantología en la Clínica Estomatológica Provincial Docente “Dr. Ismael Clark y Mascaró” de Camagüey, por ausencia de incisivos central y lateral superior derecho (11 y 12. Se valoró por el equipo multidisciplinario, el cual planteó cerrar el espacio de la brecha edente con aparatología ortodóncica fija y después realizar cirugía de avanzada y la colocación de un implante Leader Nano. La rehabilitación protésica se realizó a los ocho meses. Se demostró la eficacia de la realización de tratamiento ortodóncico previo a la colocación de implantes dentales así como el restablecimiento del estado estético y psicológico del paciente.

  12. Displasia ectodérmica en odontopediatría

    Directory of Open Access Journals (Sweden)

    Marcelle Danelon

    2018-01-01

    Full Text Available La displasia ectodérmica (DE se caracteriza por ser una enfermedad hereditaria que consiste en alteraciones genéticas y ambientales, provocando hipodoncia, distrofia en uñas, cabello escaso y anomalías dentarias. El tratamiento de rehabilitación en pacientes pediátricos con DE es difícil debido al continuo crecimiento y desarrollo cráneo facial de estos niños. El presente trabajo tiene como objetivo relatar un caso clínico de rehabilitación oral en paciente pediátrico diagnosticado con DE. Paciente de sexo femenino, con 5 años y 6 meses de edad que compareció a la clínica de odontopediatría en la UNIDERP. Al examen físico, extra oral, se constató que la paciente era respiradora bucal, y presentaba disminución del tercio inferior de la cara, labios protruidos y evertidos, frente prominente, nariz en “silla de montar”, escasez de cabello, pestañas y cejas, piel fina y seca. En el examen intraoral se observó ausencia de los siguientes dientes: 51/52, 61/62/63, 71/72, 81/82, y aspecto conoide de los dientes 53, 73 y 83. Al examen radiográfico se constató agenesia de 9 dientes primarios y de los gérmenes de los siguientes dientes permanentes: 11/12/13, 21/22/23, 41/42, 31/32, se observó la presencia de los gérmenes de los dientes 33 y 43. Con base en las características físicas y radiográficas se diagnosticó displasia ectodérmica hidrótica. Como conducta clínica, se optó por la instalación de mantenedores estéticos funcionales removibles, con el fin de favorecer la fonación, deglución, tonicidad muscular labial y lingual y el desenvolvimiento social.

  13. La influencia de la superficie de los implantes en la oseointegración. Un estudio histomorfométrico en animales

    OpenAIRE

    Ortiz García, Iván

    2011-01-01

    La implantología oral ha revolucionado la práctica odontológica al proporcionar un conjunto de técnicas diagnósticas, quirúrgicas y restauradoras integradas que constituyen la mejor opción terapéutica anatomofuncional en la sustitución artificial de los dientes perdidos. En este sentido, desde tiempos muy remotos el hombre ha intentado sustituir los dientes perdidos, ya sea por caries, traumatismo s o enfermedad periodontal, por otros elementos que restaurasen la función y la estética, pero n...

  14. Manejo clínico del quiste periapical

    Directory of Open Access Journals (Sweden)

    Clara Vergara Hernández

    2013-10-01

    Full Text Available ResumenEl quiste periapical es una lesión inflamatoria de los maxilares formada en el periápice de dientes con pulpa necrótica e infectada siendo una secuela directa de un granuloma apical, están asociados a la raíz dentaria y se encuentran con mayor frecuencia en el maxilar superior. Por lo general no provocan síntomas y su lenta evolución hace que el paciente no se percate del mismo hasta que aparece la asimetría facial. Se presenta un caso correspondiente a un paciente masculino con lesión de aspecto clínico tumoral en hemicara izquierda. Al examen radiográfico se observa imagen radiolúcida a nivel de incisivo central superior que continua con el ligamento periodontal. Se realiza biopsia por aspiración y basado en el estudio histopatológico, se diagnostica como quiste periapical. La conducta que se siguió con respecto al tratamiento fue quirúrgica. (DUAZARY 2010, 219 - 222AbstractThe periapical cyst it is an inflammatory injury of maxillaries formed in periápice of teeth with necrotic and infected pulp being a direct sequel of granuloma apical, is associate to the dental root and they are most frequently in superior maxilary. By the general they do not cause symptoms and its slow evolution causes that the patient does not notice of he himself until appears the face asymmetry. A case is exposed corresponding to a masculine patient with left injury of tumor like clinical aspect in hemicara. The radiographic examination radiolúcida image at level of superior central incisor is observed that continuous with the periodontal ligament. It makes biopsy by aspiration and based on the histopatológico study, it is diagnosed like periapical cyst. The conduct that was followed with respect to the treatment was surgical.Keywords: Periapical cyst; periapical disease; apical granuloma; periodontal ligament.

  15. Frenectomía en el tratamiento de la anquiloglosia - Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Danuze Batista Lamas Gravina

    2016-01-01

    Full Text Available Introducción: El frenillo lingual es una membrana mucosa adherida desde la base de la lengua hasta el reborde alveolar. Esta estructura en el recién nacido tiene una actuación importante en el acto de succión y amamantamiento. Un frenillo lingual corto influencia en la posición de los dientes en los arcos dentarios, en el amamantamiento y dificulta los movimientos de la lengua. Este aspecto patológico se llama anquiloglosia. Reporte de Caso: Este trabajo reporta el caso de una niña, 04 años de edad, que compareció con su padre a la Clínica de Odontopediatría de la Universidad Católica de Brasilia, con la queja de “lengua presa”. Tras la anamnesis, se diagnosticó anquiloglosia. La niña presentaba el frenillo lingual adherido a la base de la lengua, presencia de diastema entre los incisivos centrales inferiores, lengua en formato de corazón cuando proyectada y dificultad para articulación de determinados fonemas. Luego de la firma del Formulario de Consentimiento informado por el responsable, se propuso como plan de tratamiento su remoción quirúrgica: Frenectomía. La cirugía fue realizada con éxito, con remoción de la membrana adherida, lo que le posibilitó a la niña una mejora inmediata en su habla. La niña fue encaminada para fonoaudiología para recuperar fonemas que no lograba pronunciar. Conclusión: La frenectomía le devolvió las funciones de la lengua al sistema estomatognático de la paciente, permitiendo la ejecución de sus funciones normales como alimentación, deglución y correcta articulación de palabras.

  16. Estudio in vitro sobre los efectos de la cocaína sobre los tejidos duros del diente In vitro study on the effects of cocaine on the hard tissues of the tooth

    Directory of Open Access Journals (Sweden)

    Eduvigis Solórzano Navarro

    2008-12-01

    Full Text Available El uso de los derivados de la cocaína es un problema de salud pública en continuo crecimiento. Estas drogas son frecuentemente frotadas sobre la mucosa gingival, pero sus efectos son poco conocidos y de difícil diagnóstico. Con este trabajo se pretende demostrar in vitro, que la aplicación por frotación de la cocaína sobre la superficie dentaria produce erosión del esmalte. Se seleccionaron 30 dientes sanos, distribuidos aleatoriamente en 3 grupos, a los cuales se frotó sobre la superficie vestibular clorhidrato de cocaína, basuco y limón (grupo control respectivamente, durante 40 semanas. Las lesiones más características observadas fueron fractura y pérdida de sustancia dura, demostrando así que la aplicación tópica y continua de drogas en cavidad bucal produce lesiones en los tejidos duros del diente.The use of cocaine derivatives is an increasingly growing public health problem. These drugs are frequently rubbed on the gingival mucosa, but their efffects are little known and difficult to be diagnosed. This paper pretends to prove in vitro that the rubbing of cocaine on the dental surface produces enamel erosion. 30 healthy teeth were selected and distributed at random into 3 groups that were rubbed cocaine hydrochloride, bazuko and lemon (control group on the vestibular surface, respectively, during 40 weeks. The most observed characteristic lesions were fracture and loss of the dental hard substance, which showed that the topical and continual application of drugs on the oral cavity causes lesions in the hard tissues of the tooth.

  17. Bibliotheekgebruik in het objectgeoriënteerd programmeeronderwijs [The Use of Class Libraries in Object Oriented Programming Courses

    NARCIS (Netherlands)

    van den Berg, Klaas

    1997-01-01

    Het gebruik van bibliotheken met klassen is een essentieel onderdeel van objectgeoriënteerde software-ontwikkeling. In het objectgeoriënteerd programmeeronderwijs dient dit bibliotheekgebruik als leerdoel expliciet te worden opgenomen. De in de praktijk gebruikte standaardbibliotheken zijn echter

  18. Paaigebieden

    NARCIS (Netherlands)

    Hofstede, ter R.

    2006-01-01

    Rijkswaterstaat (RWS) dient als beheerder van de Noordzee en de kustwateren deskundig en adequaat te opereren bij milieucalamiteiten en rampen. Daarvoor is kennis nodig betreffende het ecologisch en economisch functioneren van de Nederlandse mariene wateren. IMARES draagt hieraan bij door te

  19. Orienterend onderzoek naar de rol van bodemverzuring bij bosschade in Friesland

    NARCIS (Netherlands)

    Breemen, van N.; Peek, G.J.W.C.; Poortinga, G.; Westeringh, van de W.

    1984-01-01

    Rapportage van een onderzoek in twee Friese bossen betreffende de relatie tussen waargenomen schade aan bossen en bodemverzuring. Dit rapport dient, naast een onderzoek van Staatsbosbeheer naar de vitaliteit van de Nederlandse bossen, als basis voor een inventarisatie van de in Nederland aanwezige

  20. Histomorfología de la atrición en dientes temporarios

    Directory of Open Access Journals (Sweden)

    Melisa R Lezcano

    Full Text Available Resumen En la Facultad de Odontología de la Universidad Nacional del Nordeste, provincia de Corrientes, Argentina, se desarrolló un trabajo de investigación en el cual se estudiaron las características histológicas que presentaban el esmalte y la dentina de piezas dentarias temporarias bajo el proceso fisiológico de la atrición. Para dicho estudio, se obtuvieron 25 piezas dentarias temporarias de pacientes que concurrieron a la Cátedra de Odontopediatría para su atención. Las muestras fueron protocolizadas y clasificadas según la escala de desgaste dentario de Gerasimov modificada. Las piezas dentarias se procesaron mediante la técnica de desgaste para su observación al microscopio óptico, determinándose que el 48% de los casos el desgaste correspondía a grado I, el 36% al grado II y el resto al grado III. En los casos que afectó al esmalte únicamente se observó la sección de los prismas del esmalte. Cuando afectó esmalte y dentina en los grados II y III de la escala se observan tanto casos de dentina esclerótica como de trayectos muertos

  1. Anomalías morfológicas en los dientes del cibario de Lutzomyia evansi (Diptera: Psychodidae en el estado Trujillo, Venezuela

    Directory of Open Access Journals (Sweden)

    Yolanda Méndez-de Daboín

    2015-06-01

    Full Text Available Introducción. Lutzomyia evansi es un reconocido vector de Leishmania infantum en Colombia y Venezuela. Objetivo. Describir e ilustrar las anomalías morfológicas presentes en el cibario de hembras de Lu. evansi capturadas en un foco rural de leishmaniasis visceral en Trujillo, Venezuela. Materiales y métodos. Para la captura de los flebótomos se utilizaron tres diferentes métodos (trampa Shannon, trampas de luz del tipo CDC y capturas en reposo. En la identificación taxonómica se siguió la clave de Young & Duncan (1994 y los diseños biológicos se hicieron utilizando un microscopio óptico con cámara clara. Resultados. En 3.477 especímenes de Lu. evansi se detectaron cuatro (0,12 % hembras con diferentes anomalías en el cibario. Conclusión. Algunos especímenes de Lu. evansi pueden presentar anomalías morfológicas relacionadas con aumento del número de los dientes en el cibario y con su disposición. La detección de estas anomalías en poblaciones naturales de Lu. evansi puede evitar dificultades y confusiones en el momento de la identificación taxonómica de los especímenes teratomorfos, reduciendo así el riesgo de incurrir en errores taxonómicos.

  2. Variability interexaminer of chronic apical periodontitis diagnostics in panoramic radiographs; Variabilidad interexaminador del diagnostico de periodontitis apical cronica en radiografias panoramicas

    Energy Technology Data Exchange (ETDEWEB)

    Montero Aguilar, Mauricio; Zeledon Mayorga, Rodolfo; Ramirez Mora, Tatiana; Monestel Umana, Silvia [Univ. de Costa Rica, Facultad de Odontologia (Costa Rica)

    2009-01-15

    The accuracy of radiological diagnosis of Apical Periodontitis (AP) is reported between examiners with differents levels of clinical experience using panoramic radiographs. 1032 teeth in 41 panoramic radiographs have been diagnosed. The evaluation of the x-rays and radiological diagnosis is performed by three independent dentists for AP to each tooth. The teeth have presented without radiological signs of AP in 96.6%. The number of teeth classified with an uncertain diagnosis of AP at the has been inversely proportional to the number of years of experience of the examiner. The examiner A has been used as a reference and compared the diagnoses of other examiners.The percentage agreement for all teeth was 95% for examiner B and 94% for examiner C. Kappa for all has been of 0.44 for examiner B and 0.43 for examiner C. The different categories were analyzed separately, the inferior teeth and the anterior teeth have obtained the best results. The level of clinical experience of the examiner has been indifferent in the diagnosis of AP in panoramic radiographs; however, it is important experience in the number of radiographs extras that will be needed to give a radiological diagnosis definitive. The panoramic radiographs were reliable diagnostic tools for AP. (author) [Spanish] La precision del diagnostico radiologico de la Periodontitis Apical Cronica (PAC) es reportado entre examinadores con diferentes niveles de experiencia clinica al utilizar radiografias panoramicas. 1032 dientes en 41 radiografias panoramicas han sido diagnosticados. La evaluacion de las radiografias y el diagnostico radiologico es realizado por tres odontologos independientes para la PAC a cada diente. Los dientes tampoco han presentado signos radiologicos de PAC en 96.6%. El numero de dientes clasificados con un diagnostico incierto de PAC ha sido inversamente proporcional al numero de anos de experiencia del examinador. El examinador A ha sido utilizado como referencia y se han comparado los

  3. Diseño y cálculo de un reductor de velocidad para un polipasto de uso industrial de engranajes cilíndricos de dientes helicoidales, con hipótesis de cálculo para los dos sentidos de giro de motor

    OpenAIRE

    SORO SALA, SANTIAGO

    2016-01-01

    [ES] El objetivo de este trabajo final de grado es el de diseñar y calcular un reductor de velocidades, de uso industrial, para un polipasto de cadena. El reductor de velocidades será de dos etapas, de engranajes cilíndricos de dientes helicoidales. Se realizan los cálculos para las hipótesis de giro horario y antihorario, Esto se debe a que este tipo de engranajes, transmiten esfuerzos axiales, de dirección variable según su sentido de giro. En el proceso de cálculo del red...

  4. Satisfacción con el aspecto dental general y tratamientos deseados en estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    Clarisse Virginia Díaz Reissner

    2015-08-01

    Full Text Available La apariencia dental es considerada un componente de la belleza facial, que al ser restaurada por el odontólogo, podría influir con un efecto positivo en la valoración personal y la calidad de vida. El objetivo del estudio fue determinar la satisfacción general con la apariencia dental en estudiantes de las carreras de Artes Visuales y Diseño de Indumentaria del Instituto Superior de Arte de la Facultad de Arquitectura Diseño y Arte de la Universidad Nacional de Asunción, matriculados en el 2014. Se aplicó un cuestionario que contenía preguntas sobre datos demográficos, satisfacción con el aspecto dental general y con diversos aspectos dentales, así como también sobre el tratamiento estético deseado. La muestra quedó conformada por 108 estudiantes, que corresponde al 49,1% de la población. Se observó que el 48,2% se encontraba insatisfecho con el aspecto general de sus dientes, siendo los tratamientos de elección: blanqueamiento (63,9% y ortodoncia (47,2%. Los factores predisponentes a la insatisfacción fueron residir en Gran Asunción e interior del país y percibir sus dientes como desalineados. Por otro lado, favoreció la satisfacción el haberse sentirse a gusto con el color de sus dientes.

  5. Enkele kanttekeningen bij de strafbaarstelling van stalking

    NARCIS (Netherlands)

    van Klink, B.M.J.; Royakkers, L.M.M.

    1998-01-01

    In dit artikel gaan wij nader in op het fenomeen stalking in het algemeen en het wetsvoorstel dienaangaande in het bijzonder. §2 biedt een conceptuele analyse van het begrip ¿belaging', dat door ons wordt opgevat als een vorm van geestelijke mishandeling. Beseft dient te worden dat het hierbij niet

  6. Relation between agenesis and shape anomaly of maxillary lateral incisors and canine impaction

    Directory of Open Access Journals (Sweden)

    Anísio Bueno de Carvalho

    2012-12-01

    Full Text Available OBJECTIVE: The purpose was to obtain information about the relation between agenesis and shape anomaly of maxillary lateral incisors and canine impaction. METHODS: Seventy-three patients with canine impaction and 73 control patients, without canine impaction, were evaluated. The mesiodistal distances of the maxillary lateral incisors adjacent to the impacted canines and the correspondent mandibular lateral incisors were measured. The adjacent lateral incisors were classified in: 1 - absent, 2 - small, 3 - peg-shaped, 4 - standard. RESULTS: The results showed that among the patients with impacted canines, there were 21 anomalous teeth (small and peg-shaped and among the control patients there were only three small and peg-shaped teeth, with a statistically significant difference (p = 0.001. No patients were found with impacted canines and absent lateral incisors. CONCLUSION: It was concluded that in patients with anomalous lateral incisors (small and peg-shaped there is a probability to present impacted canines and this must be considered.OBJETIVO: o objetivo foi obter informação sobre a relação existente entre a agenesia e/ou anomalia de forma de incisivos laterais superiores e impacção de caninos. MÉTODOS: foram avaliados 73 pacientes com impacção de caninos e 73 pacientes controle, sem impacção de caninos. Foram medidas as distâncias mesiodistais dos incisivos laterais superiores adjacentes aos caninos impactados e os incisivos laterais correspondentes inferiores. Os incisivos laterais adjacentes foram classificados em: 1 - ausentes; 2 - pequenos; 3 - conoides; 4 - normais. RESULTADOS: os resultados mostraram que no grupo de pacientes com caninos impactados foram encontrados 22 dentes anômalos (pequenos e conoides, e no grupo controle apenas três dentes pequenos e conoides, sendo uma diferença estatisticamente significativa (p=0,001. Não foram encontrados pacientes com canino impactado e incisivo lateral ausente. CONCLUS

  7. Alltägliche Lebensführung in der Kindergartenpraxis

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    dient dem Workshop als Grundlage, um mit Interessierten auch über deren Praxiserfahrungen mit Kindern (ob das nun „Forschung“ oder eine andere Praxis ist) zu diskutieren. Wer Lust hat, möge mir bis zum 1.9. 1-2 Seiten zum eigenen Projekt bzw. der eigenen Fragestellung per Mail zu schicken: VERSTECKTE...

  8. Efecto de la prednisona en la magnitud del movimiento dentario ortodóntico en ratas

    OpenAIRE

    Ruiz Ramirez, Eliberto

    2017-01-01

    Evalúa el efecto de la prednisona, glucocorticoide de acción intermedia, y su efecto en el movimiento dentario ortodóntico en ratas. Se utilizan 20 ratas albinas machos Holtzman, a las cuales se les coloca un aparato ortodóntico disyuntor entre sus incisivos centrales superiores, luego son divididas de manera aleatoria en dos grupos: Grupo control, el cual no recibe ningún tratamiento farmacológico y grupo experimental, al cual se le administra prednisona 5 días antes de la colocación del apa...

  9. Implante imediato com provisório imediato em incisivo central superior

    OpenAIRE

    Gomes Junior, Raul

    2007-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-graduação em Odontologia Com a reabilitação cirúrgica e protética na mesma sessão, através da implantodontia, em região estética superior, elimina-se a realização de uma segunda intervenção cirúrgica e a utilização de uma prótese provisória removível, além de favorecer o estado emocional do paciente. Este estudo teve como objetivo determinar quantitativamente a reabsorção óssea ver...

  10. Automatisierung von HiL Tests

    OpenAIRE

    Asbach, Lennart; Ebrecht, Lars

    2010-01-01

    Automatisierung von HiL Tests. Darstellung und Bewertung einer praktischen Umsetzung. Das Poster zeigt die Motivation, die Durchführung, einen aktuellen Stand und einen Ausblick der Testautomatisierung im Bahnlabor RailSiTe. Als Beispiel dient der Konformitätstest von ETCS-Onboard Zugrechnern, um die Einführung von ETCS zu unterstützen.

  11. Anatomía de la furca dentaria y lesiones de furcación. Parte 1. Revisión de tema

    Directory of Open Access Journals (Sweden)

    Yuri Alejandro Castro Rodríguez

    2015-01-01

    Full Text Available La enfermedad periodontal, debida principalmente a la presencia de la biopelícula, provoca la pérdida de inserción y de hueso a nivel de las raíces dentales, el avance de la patología periodontal conlleva en los dientes multiradiculares a compromisos en la zona de furca; estos constituyen una lesión particular, única y difícil de tratar por las características anatómicas de la zona. La furca dental es la zona anatómica que comprende al área de división de las raíces de dientes multiradiculares; ya sean premolares o molares. Las patologías que afectan esta zona son muy complejas y reciben el nombre de lesiones de furcación o lesiones de la furca. Los defectos en furcaciones representan un gran reto para los terapistas debido a sus características anatómicas y a su variabilidad en cuanto a la forma de respuesta al tratamiento. La pérdida de inserción se desarrolla en sentido horizontal o vertical. Un amplio rango de modalidades de tratamiento han sido dirigidos a mantener esta área anatómica. El presente artículo recopila la información más actualizada y relevante de bases de datos como PubMed y Cochrane sobre la anatomía de dientes multiradiculares, la furca dentaria así como las consideraciones para el diagnóstico de las lesiones de furcación.

  12. Frecuencia de restauraciones plásticas directas en dientes posteriores en tres centros públicos de Asunción

    Directory of Open Access Journals (Sweden)

    Isolde Fischer

    2015-08-01

    Full Text Available En la selección del material de restauración, para rehabilitar una pieza dentaria posterior que ha sufrido una lesión, el operador puede optar entre la amalgama o la resina compuesta, equilibrando las ventajas y desventajas de cada una. Este estudio de enfoque mixto, de diseño descriptivo, retrospectivo y transversal, tuvo como objetivo determinar la frecuencia en el uso de los biomateriales restauradores en dientes posteriores. Se utilizó un cuestionario aplicado a una muestra de 164 sujetos tratados previamente en tres centros públicos de referencia en Asunción en 2.013 y 2.014. El trabajo se complementó con una técnica cualitativa, la entrevista a grupo focal, en dos grupos distintos; por un lado a docentes y por el otro, a comerciantes de artículos dentales. Se observó que la resina es el material de uso más frecuente (77,7% seguido del ionómero de vidrio (18,4%, siendo la amalgama el menos utilizado (4,2%. Docentes y comerciantes entrevistados coincidieron en opinar que la resina es el material más utilizado por el factor estético, y que la amalgama se halla francamente en desuso, sea por su falta de estética o por efectos tóxicos, aunque pocos docentes conocían los criterios actuales sobre los efectos adversos de amalgamas y resinas, emitidos por entes sanitarios internacionales. Se propone tener en cuenta estos resultados para la reorientación del curriculum en la educación odontológica respecto a los biomateriales restauradores si fuese necesario, sobre fundamentos válidos y coherentes con las necesidades del contexto.

  13. Erinnerungen. Aus dem Feldzuge der Franzosen in Russland unter Napoleon im Jahre 1812, von einem preußischen Bombardier, dem jetzigen Major Weinberger. Unveröffentlichtes Manuskript (1849), herausgegeben von Peter-Michael Berger

    OpenAIRE

    Weinberger, Friedrich Ludwig

    2012-01-01

    Friedrich Ludwig Weinberger (1794–1869) diente im Juni 1812 als Freiwilliger bei der Königsberger Garnisonsartillerie. Diese 400 Soldaten wurden von Napoleon in die Garde seiner Grande Armée zur Invasion Russlands zwangsweise eingegliedert. Als einer von nur 13 Überlebenden seiner Truppe kehrte Weinberger im März 1813 aus russischem Gewahrsam zurück. Über seine Erlebnisse beim Vormarsch, den Kämpfen, der Besetzung Moskaus, dem Rückzug und der Heimkehr verfasste er einen Bericht, den er m...

  14. Incremento del índice de dientes permanentes cariados, perdidos por caries y obturados, entre escolares de Loja, España Increasing decayed, missing, and filled teeth index among school children in Loja, Spain

    Directory of Open Access Journals (Sweden)

    Diego Almagro-Nievas

    2001-06-01

    Full Text Available Objetivo. Identificar variables clínicas, socioeconómicas y de hábitos alimentarios e higiénicos, predictoras del incremento del índice (DMFT, por sus siglas en inglés de dientes definitivos que están cariados, ausentes por caries y obturados en la cohorte de escolares de la localidad de Loja, Granada, España, en un trienio (1994-1997. Material y métodos. Estudio de cohorte retrospectivo sobre 812 alumnos a los que se les realizó una exploración dental siguiendo la metodología recomendada por la Organización Mundial de la Salud. Para la construcción de modelos se usa la metodología de regresión logística. Resultado. El índice DMFT de toda la cohorte pasó de 1.86 a 4.5 (en el trienio y en los miembros de la cohorte de 12 años, de 3.71 a 4.47. El DMFT medio está asociado con el incremento del DMFT final. La asistencia al colegio 3 tiene un riesgo relativo (RR de 0.69 (IC 95% 0.60-0.8 frente a la asistencia al colegio 4, y un RR de 0.78 (IC 95% 0.67-0.90 frente a la asistencia al colegio 5. Conclusión. En el modelo final se encontró que el riesgo de incrementar la caries es por el DMFT medio del trienio, y que el factor protector es la asistencia al colegio 3. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlObjective. To identify the clinical, socioeconomic, dietary, and hygienic predictors of the increasing Decayed, Missing, and Filled Teeth (DMFT index, in a cohort of school children in Loja, Granada, Spain, during a three-year period (1994-1997. Material and methods. A retrospective cohort study was conducted in 812 students to measure the DMFT index, using the methods recommended by the World Health Organization. Statistical analysis was conducted using logistic regression models. Results. During the study period, the DMFT index increased from 1.86 to 4.5 for the study cohort as a whole, and from 3.71 to 4.47 among twelve-year olds. The DMFT at mid-period was

  15. Efectos de la chicha morada y café sobre el esmalte dental bovino blanqueado con peróxido de hidrógeno

    OpenAIRE

    Castillo-Ghiotto, Gisella; Delgado-Cotrina, Leyla; Evangelista-Alva, Alexis

    2014-01-01

    Objetivo: El propósito de este estudio in vitro fue evaluar la susceptibilidad del esmalte dental bovino expuesto a chicha morada y café después del blanqueamiento con peróxido de hidrógeno (PH) al 35% con y sin calcio. Material y métodos: Setenta y dos dientes de bovino fueron blanqueados con peróxido de hidrógeno al 35% con y sin calcio (Whiteness HP Blue® - FGM y Whiteness HP Maxx® - FGM, respectivamente) y se expusieron al café instantáneo, refresco de maíz morado artificial y saliva (con...

  16. Resistencia de dientes restaurados con postes prefabricados ante cargas de máxima intercuspidación, masticación y bruxismo Resistance of teeth restored with prefabricated posts to maximum intercuspidation loads, mastication and bruxism

    Directory of Open Access Journals (Sweden)

    Santiago Correa Vélez

    2013-03-01

    Full Text Available Objetivo: determinar por el método de los elementos finitos la resistencia de dientes restaurados con postes prefabricados ante cargas estáticas de máxima intercuspidación y cargas cíclicas de masticación y bruxismo y analizar el efecto de la pérdida periodontal en la resistencia de las restauraciones. Métodos: se realizó una investigación in vitro mediante el método de los elementos finitos de dientes con pérdida periodontal, rehabilitados con postes prefabricados en fibra de vidrio, carbono y titanio. Los dientes fueron reconstruidos a partir de imágenes tomográficas de un paciente periodontalmente sano. Resultados: se muestra que ante cargas estáticas las rehabilitaciones no presentan tendencia a la falla, independientemente del material del poste o del grado de pérdida periodontal. En el caso de bruxismo y pérdida periodontal de 4 mm, la dentina presenta una durabilidad de 60 000 ciclos independiente del material del poste. Para cargas de masticación y periodonto sano, la falla en la dentina ocurre a los 100 000 ciclos con poste en titanio, 200 000 ciclos con poste en fibra de carbono y 1 100 000 ciclos con poste en fibra de vidrio. Para una pérdida periodontal de 2 mm la durabilidad de la dentina se reduce a 4 000 ciclos con poste en titanio, 5 000 ciclos con poste en fibra de carbono y 7 000 ciclos con poste en fibra de vidrio. Para pérdida periodontal de 4 mm, la durabilidad de la dentina se estima en 1 000 ciclos, independientemente del material del poste utilizado. Conclusiones: ante carga estática de máxima intercuspidación las rehabilitaciones con postes prefabricados en fibra de vidrio, carbono y titanio no presentan tendencia a la falla, independientemente del grado de pérdida periodontal. Ante cargas cíclicas, los postes prefabricados presentan una vida útil infinita, y es la dentina la estructura más afectada ante dichos eventos.Objective: using the finite element method, determine the resistance of

  17. Maloclusiones en dentición mixta en un grupo de niños Venezolanos VIH/SIDA

    Directory of Open Access Journals (Sweden)

    María Elena Guerra

    2013-07-01

    Full Text Available En niños VIH/SIDA son múltiples las patologías bucales siendo las maloclusiones en dentición mixta las menos estudiadas. Objetivo: Determinar las maloclusiones dentales presentes en niños VIH/SIDA que acudieron al CAPEI/UCV. Materiales y métodos: Estudio descriptivo transversal y prospectivo en una muestra de 53 niños VIH/ SIDA que acudieron al CAPEI/UCV durante el año 2011, se analizaron los tipos de maloclusión dental y la prevalencia de maloclusiones. Resultados: La edad media fue 8,5 años, la prevalencia de maloclusiones fue de un 100%, el 100% presentó perdida prematura de algún diente primario, La maloclusión más frecuente fue la Clase II, observandose en 29 pacientes (54,7% seguida de clase I en 21 pacientes (40% que corresponden en su totalidad a Clase I tipo 5 causada por perdida prematura del molares primarios y Clase III en 3 pacientes (5%. Conclusión: Resaltamos que perdida prematura de dientes primarios la etiología más frecuente de las maloclusiones

  18. Tratamiento integrado ortoperiodontal en la periodontitis juvenil: Presentación de un caso Orthoperiodontal integrated treatment in juvenile periodontitis: A case report

    Directory of Open Access Journals (Sweden)

    Tatiana Peña Ruiz

    2007-12-01

    Full Text Available La periodontitis juvenil es un término que se usa para incluir diferentes tipos de periodontitis que afectan a jóvenes sanos. Esta entidad afecta a personas en la segunda década de la vida y se ha dividido en 2 formas: la localizada y la generalizada. Se presenta el caso de una paciente femenina de 13 años de edad, mestiza, estudiante de canto coral, la cual llevaba año y medio de tratamiento de ortodoncia, que después de instaurados los aparatos fijos, abandonó el seguimiento por consulta de la especialidad. Al examen físico se detecta una lesión de distribución márgino papilar, con pérdida de la morfología gingival, consistencia duroelástica, aspecto fibroedematoso y color rosado intenso con manchas melánicas aisladas, gingivorragia al sondeo, dolor y movilidad en dientes anterosuperiores y en menor escala en los anteroinferiores, bolsas periodontales de hasta 8 mm y pérdidas óseas horizontales y verticales localizadas en incisivos superiores e inferiores y en los primeros molares permanentes, constatada en las radiografías. Se presenta el tratamiento indicado y la evolución del caso mediante seguimiento imagenológico.Juvenile periodontitis is a term used to include different types of periodontitis affecting healthy young individuals. This entity affects persons on the second decade of life, and it has been divided into 2 forms: the localized and the generalized. The case of a 13-year-old black female student of choral singing, who had been under orthodontia treatment for a year and a half, and that after having the fixed appliances abandoned the follow-up, was presented. On the physical examination, it was detected a lesion of the marginal and papillary distribution with loss of gingival morphology, hardelastic consistency, fibroedematous aspect and dark pink colour with isolated melanic stains, gingivorrhagia, pain and mobility in the anterosuperior teeth, and in a less scale in the anteroinferior, periodontal pockets of

  19. Estudo dos parâmetros periodontais para a avaliação morfológica da papila gengival interdental na região anterior da maxila

    OpenAIRE

    Marinho, Carlos Frederico de Carvalho

    2007-01-01

    O alto grau de exigência estética de pacientes e profissionais no atual estágio da implantodontia implica num exame de diagnóstico extremamente apurado, devido as possíveis alterações na margem gengival e na papila interproximal advindas do tratamento com implantes unitários. O objetivo deste trabalho foi avaliar o efeito dos parâmetros periodontais sobre a altura da papila interdental na região de incisivos centrais, incisivos laterais, caninos e primeiros pré-molares superior...

  20. Supernumerarios : Anomalías dentarias de número más frecuentes en la clínica odontopediátrica

    OpenAIRE

    Hernández, Sandra Fabiana; Iriquin, Stella Maris; Ruiz, Miriam Ester; Rom, Mónica Graciela

    2017-01-01

    Los dientes supernumerarios o hiperodoncia se han definido como dientes que exceden de la fórmula dental normal, independientemente de su forma y localización. Esta anomalía parece tener componente hereditario que pueden estar o no asociadas a algún síndrome. La presencia de dientes supernumerarios puede ser doble, múltiple y única, siendo ésta la más frecuente. La prevalencia es mayor en la dentición permanente y su presencia es más frecuente en el sexo masculino. Los dientes supernumerarios...

  1. Erkennung, Modellierung und Vermeidung von Hubschrauberlärm durch Blatt-Wirbel-Interaktionen

    OpenAIRE

    Gläßel, Holger

    2010-01-01

    In dieser Arbeit wird ein System zur Erkennung und Vermeidung von impulsivem Hubschrauberlärm aufgrund Blatt-Wirbel-Interaktionen (blade-vortex interaction, BVI) entwickelt. Als Auslegungsbasis dient der Entwurf eines vereinfachten neuronalen und somit datengetriebenen Modells des Wirbelnachlaufs. Die Ergebnisse aus der Simulation des Nachlaufmodells führen zur logischen Ableitung einer sehr einfachen, allgemein gültigen Regelstrategie zur Kontrolle der Wirbelflugbahnen. Aufgrund der effizien...

  2. Gesamtfahrzeugsimulation betriebsfestigkeitsrelevanter Manöver unter Berücksichtigung von Fahrwerkregelsystemen

    OpenAIRE

    Brandes, Sebastian Jürgen

    2016-01-01

    In der Automobilbranche dient im Bereich der betriebsfesten Bemessung des Fahrwerks die Methode der Mehrkörpersysteme als Analyseverfahren zur Ermittlung von Bewegungen und Schnittgrößen an den Fahrwerksbauteilen. Eine der aktuellen Herausforderungen hierbei ist der zunehmende interdisziplinäre Charakter in Form von mechatronischen Fahrwerkssystemen. In rein virtuellen Entwicklungsphasen kann deren Einfluss auf die Fahrwerksbelastungen einzig anhand von Gesamtfahrzeugsimulationen ermittelt we...

  3. Odontoma compuesto como causa de retención dentaria: Presentación de un caso Compound odontoma as a cause of dental retention: A case presentation

    Directory of Open Access Journals (Sweden)

    Juan Carlos Quintana Díaz

    2006-08-01

    Full Text Available Se presenta el caso de un paciente masculino de 10 años de edad con presencia de retención dentaria del incisivo central superior derecho causado por la presencia de un odontoma compuesto, cuyo diagnóstico se corrobora clínica e histológicamente. El defecto óseo residual a la enucleación de dicho tumor fue rellenado con hidroxiapatita porosa del tipo HAP- 200 y el diente fue llevado a su posición en la arcada dentaria con la ayuda de aparatología ortodóncica. Con este tipo de tratamiento quirúrgico-ortodóncico se logró en el paciente un resultado estético y funcional muy bueno. Se corrobora que este tipo de lesión es una de las causas locales de retención dentaria.The case of a male patient aged 10-years with dental retention of right superior central incisor caused by a compound odontoma was presented in this paper. The diagnosis of this odontoma was confirmed clinically and histologically. The residual osseous defect after enucleation of such tumor was filled with HAP-200 type porous hydroxiapatite and the tooth was taken back to its position in dental archade with orthodontic implements. Thanks to this kind of surgical/orthodontic treatment, it was possible to reach a very good functional aesthetic result in this patient. It was confirmed that this type of lesion is one of the local causes of dental retention.

  4. Determinación y localización del plano oclusal en la rehabilitación de pacientes adultos mayores usuarios de prótesis completas

    OpenAIRE

    Vera, Mónica Mabel

    2015-01-01

    La orientación del plano oclusal es importante en el tratamiento protético en desdentados, al perder los dientes naturales las referencias oclusales están ausentes. Objetivo: Determinar el plano de oclusión posterior más adecuado que favorezca la funcionalidad de la rehabilitación protésica y conservación del reborde residual en la prótesis total removible. Determinar el punto anatómico posterior que conformará el plano protético más paralelo al reborde residual. Metodolog...

  5. Estudio de predicción de vida a fatiga de implantes dentales de titanio y de sus principales tipos de conexiones implantoprotésicas

    OpenAIRE

    Ivorra Server, Carlos

    2017-01-01

    Tesis Doctoral leída en la Universidad Rey Juan Carlos de Madrid en 2017. Directores de la Tesis: Juan Carlos Prados Frutos y Carlos Navarro Vila Se denomina implante dental al elemento aloplástico que se aloja en el tejido óseo o debajo del periostio con la finalidad de reemplazar los dientes ausentes (Schou et al. 2000). La Academia Americana de Implantología (AAID, por sus siglas en inglés) define el implante dental como un elemento cilíndrico, fabricado generalmente de tita...

  6. Evaluación de la dispersión de pigmento en resinas acrílicas para la fabricación de dientes artificiales

    Directory of Open Access Journals (Sweden)

    Germán Ricaurte Avella

    2010-01-01

    Full Text Available En la primera etapa de fabricación de dientes artificiales los pigmentos se dispersan en seco en un polvo de resina acrílica conformado por finas partículas esféricas. Esta dispersión tiene características especiales diferentes a la dispersión de pigmentos en resinas líquidas usual en el campo de las pinturas y recubrimientos o en la fabricación de plásticos. No hay muchos reportes sobre los métodos de análisis y control de este tipo de procesos. En este trabajo se pretende evaluar el método de poder colorante, usual en la industria de recubrimientos, contrastando sus resultados con el porcentaje de área de pigmento adherida a las esferas de resina aplicando técnicas de procesamiento digital de imágenes (PDI a micrografías SEM. Se proponen y discuten, además, otros tres métodos alternativos basados en análisis de curvas de reflectancia, que permiten una evaluación rápida del proceso de dispersión, e incluso determinar el valor de la energía de la banda prohibida del pigmento. El método de poder colorante resulta ser el más sensible a las diferencias de dispersión. Finalmente, se aplican los cuatro métodos a una comparación entre tres procesos de molienda con diferentes energías y se discuten los resultados y las limitaciones de cada uno.

  7. Soluciones estéticas para caries del biberón

    OpenAIRE

    Gatón Hernández, Patrícia; Espasa Suárez de Deza, José Enrique; Boj Quesada, Juan Ramón

    1997-01-01

    El síndrome de caries del biberón se caracteriza por presentar múltiples superficies infiltradas por caries y seguir una evolución rápida, hallándose afectados de forma preferente los cuatro incisivos superiores. El mantenimiento de los incisivos temporales es aconsejable siempre que sea posible para el desarrollo correcto de la erupción, de la función muscular y por razones estéticas. Pero su reconstrucción presenta díficultades debido a sus peculiaridades anatómicas y a la gran destrucc...

  8. Natal Teeth, Case Report and Review

    OpenAIRE

    Fierro Monti, Claudia; Bravo Rivera, Lorena; Torres Chianale, Francisca; Álvarez Helle, Camila; Pérez Flores, Ma Antonieta

    2010-01-01

    Los dientes natales y neonatales deben valorarse con mucho cuidado; estimando su movilidad, integridad y la presencia de una úlcera (Riga Fede) en la superficie ventral de la lengua causada por su roce con el diente. Los dientes natales podrían parecerse a la dentición temporal normal en tamaño y forma, sin embargo, también pueden presentarse más pequeños, cónicos, con esmalte y dentina hipoplásicos, con poca formación o ausencia de sus raíces. La mayoría de estos dientes no son supernumerari...

  9. Análise da dissipação das tensões em dentes humanos restaurados com facetas laminadas de cerâmica, com três tipos de preparos, através do método dos elementos finitos

    OpenAIRE

    Arthur Bessone da Cruz Ferreira

    2010-01-01

    O objetivo deste trabalho é analisar in vitro a dissipação de tensões em incisivos centrais superiores humanos restaurados com facetas de cerâmica feldspática, através da análise do método dos elementos finitos, considerando cargas funcionais de mastigação e corte dos alimentos, em função de três tipos de preparos utilizados: sem proteção incisal; com proteção incisal em ângulo e com proteção incisal em degrau palatino. Foram utilizadas modelagens bidimensionais de um incisivo central superio...

  10. Potencialidad de estudios arqueobotánicos sobre tártaro dental de cazadores recolectores de la provincia de La Pampa, Argentina

    Directory of Open Access Journals (Sweden)

    Musaubach, María G.

    2012-01-01

    Full Text Available El análisis del tártaro dental desde una perspectiva arqueobotánica, constituye un acercamiento innovador en el estudio de la alimentación humana, la manipulación de fibras vegetales con los dientes y el uso de plantas con fines medicinales. Esto se debe a que la identificación de microfósiles de interés arqueológico que quedaron entrampados en el sarro nos permite conocer qué plantas fueron consumidas o manipuladas con los dientes. En este trabajo se analizan los microfósiles extraídos del tártaro dental de individuos del sitio Chenque I y se evalúa la técnica apropiada para recuperar y observar la mayor cantidad y tipo de micropartículas. Las principales morfologías de fitolitos registradas corresponden al tejido epidérmico de especies de Poaceae. Es notable la presencia de restos de tejidos epidérmicos de frutos de (sp. Prosopis y gramíneas presentes en los molares. El tejido entrampado en el sarro, resulta un dato de interés al momento de analizar las prácticas alimenticias y de salud bucal de los cazadores recolectores pampeanos.

  11. Alargamiento de corona clínica por erupción pasiva alterada

    OpenAIRE

    Reyes Doimi, Juan; Cervantes Yabar, Priscilla; Noriega Castañeda, Jorge

    2011-01-01

    Caso clínico Las alteraciones en la erupción pasiva en las que la corona anatómica del diente se ve cubierta por un exceso de tejido blando son situaciones que se presentan muy a menudo. Son en ocasiones difíciles de diagnosticar y hoy en día están adquiriendo relevancia clínica debido al aumento de la demanda de tratamientos de odontología estética. El exceso de encía al sonreír depende de muchos factores, como la excesiva dimensión vertical del maxilar superior y las malposicion...

  12. Teachers’ attitudes, knowledge, and teaching strategies towards students with special educational needs in primary inclusive education in Indonesia

    OpenAIRE

    Kurniawati, Farida

    2014-01-01

    De opname van leerlingen met beperkingen in het reguliere onderwijs (ook wel inclusief onderwijs genoemd) is een internationale trend en dient het recht op onderwijs voor iedereen, ongeacht beperking, te garanderen. De trend naar inclusief onderwijs is in 2003 formeel geïntroduceerd in Indonesië. Leerkrachten spelen een belangrijke rol in het succes van de implementatie van inclusief onderwijs. De attitudes, kennis over beperkingen, en onderwijsstrategieën van leerkrachten worden gezien als b...

  13. Aufgabenspektrum, Ausgestaltung und Geschäftsmodelle von E-Learning-Einrichtungen an Hochschulen

    OpenAIRE

    Bremer, Claudia; Eichhorn, Michael

    2015-01-01

    Im Rahmen des Projektes „Uni:prise – Universities as Enterprises“ wurden Geschäftsmodelle und Transferbeziehungen an Hochschulen untersucht und dabei auch speziell die Leistungen und Transferbeziehungen von Zentren und Einrichtungen an Hochschulen und Universitäten insbesondere aus dem Bereich E-Learning in den Blick genommen. Als Richtschnur für die Untersuchung diente dem Gesamtprojekt (Gaus & Raith, 2013) der Business Model Canvas nach Osterwalder und Pigneur (2009) mit neun Teilaspekten, ...

  14. Wissenschaftliche Netzwerke und klassifikatorische Bedeutung im Psychiatrischen Handbuch (Traité de Psychiatrie der Medizinisch-Chirurgischen Enzyklopädie (1947-1977 am Beispiel des Begriffes der Psychose

    Directory of Open Access Journals (Sweden)

    Emmanuel Delille

    2009-12-01

    Full Text Available Der deutsche Ausdruck ‘Psychose’ (Carl Friedrich Canstatt, 1841 ist der wissenschaftliche Begriff, der sich zur Bezeichnung von bestimmten Geisteskrankheiten durchgesetzt hat. Als Ausgangsperspektive für die Untersuchung dient dabei die Geschichte der wissenschaftlichen Soziabilitäten. Der Zeitraum (1947-1977 wurde entsprechend der Tätigkeit des französischen Psychiaters Henri Ey im Rahmen der Gruppe „l’Evolution Psychiatrique“ (die Psychiatrische Entwicklung abgesteckt. Ich untersuche in ...

  15. Fahrstuhlfahrten und Einstiegsschwierigkeiten. Erschließungstechniken in Georges Perecs »La Vie mode d’emploi«

    Directory of Open Access Journals (Sweden)

    Johanne Mohs

    2014-05-01

    Full Text Available Der Artikel ist eine produktionsästhetische Untersuchung zu Einstiegsschwierigkeiten in literarische Schreibprozesse und ihre Auflösung mithilfe räumlicher und sprachspielerischer Erschließungstechniken. Als Beispiel dient mir die Poetik des OuLiPo (»Ouvroir de littérature potentielle« und hier insbesondere (die Genese von Georges Perecs Roman »La vie mode d’emploi«. Genauer wird daran gezeigt, wie Perec eine blockierte Fahrstuhlfahrt als metaphorische Referenz auf seine anfängliche Schreibhemmung in den Roman einfügt und wie diese Referenz als Kommentar zur Erzählbarkeit komplexer Raum-Zeit-Gefüge im Gesellschaftsroman des 20. Jahrhunderts, insbesondere zu Marcel Prousts »Recherche«, verstanden werden kann.

  16. “VALORACIÓN DE PLACA BACTERIANA Y GINGIVITIS, MEDIANTE EL ÍNDICE DE PLACA DE O ́LEARY E ÍNDICE GINGIVAL DE LOE-SILNESS, POSTERIOR AL USO DE CLORHEXIDINA AL 0.12%, EN PACIENTES CON APARATOLOGIA FIJA”

    OpenAIRE

    Bucio Hernández, María Sugey

    2012-01-01

    Antecedentes: La búsqueda de agentes para el control de la placa bacteriana ha sido amplia, más teniendo en cuenta la importancia que ha adquirido la enfermedad periodontal en los últimos años; esto ha llevado a diversas industrias farmaceuticas a investigar en este campo. En el presente estudio se utilizo el índice Gingival de Löe y Silness (1963), por ser sencillo y valorar todas las áreas del diente, el más utilizado actualmente para medir el estado de inflamación y de salud...

  17. Regeneración ósea en alvéolos dentarios de terceros molares mandibulares empleando plasma rico en plaquetas en pacientes fumadores

    Directory of Open Access Journals (Sweden)

    Fermín Gil Cárdenas

    2018-04-01

    Full Text Available Resumen: Objetivo: El propósito del trabajo fue evaluar la regeneración ósea en alvéolos dentarios empleando como coadyuvante PRP en pacientes fumadores. Materiales y método: Estudio de intervención cuasiexperimental; se asignaron 2 grupos de estudio, uno experimental y otro de control; se realizó exodoncia a los 2 grupos de los dientes 38 y 48. Al grupo control no se aplicó PRP y al experimental se le aplicó PRP con el método de una centrifugación en el alvéolo del diente 38 y PRP con doble centrifugación en alvéolo del diente 48; se realizaron controles radiográficos a los 8, 30 y 60 días después de la cirugía para evaluar la densidad ósea. Se realizó análisis estadístico descriptivo univariado, bivariado y prueba t de Student. Resultados: Hicieron parte del estudio 19 sujetos, el 52,6% de ellos fueron de sexo masculino, al estudiar la densidad ósea en los 3 controles radiográficos del grupo experimental en el alvéolo del diente 38 y 48, no se encontraron diferencias estadísticamente significativas (p > 0,05, pero sí una leve mejoría en la cicatrización del alvéolo 48 donde se empleó PRP con el método de doble centrifugación. Al comparar los controles radiográficos del grupo control con los del grupo experimental se encontraron valores estadísticamente significativos en el grupo que se le aplicó PRP con el método de una o doble centrifugación (p .05 were found in the experimental group in the sockets of tooth 38 and 48, but there was a slight improvement in the healing of socket 48 where PRP was used with the method of double centrifugation. On comparing the follow-up x-rays of the control with those of the experimental group, statistically significant values were found in the group where PRP was applied using the single or double centrifugation method (P<.05. Conclusions: The bone regeneration process is more favourable in

  18. Characteristics and distribution of dental anomalies in a Brazilian cleft population = Características e distribuição de anomalias dentárias em uma população brasileira de portadores de fissuras lábio-palatais

    Directory of Open Access Journals (Sweden)

    Menezes, Luciane Macedo de

    2010-01-01

    Full Text Available Objetivos: Determinar a prevalência de anomalias dentárias em 200 pacientes com fissura sob tratamento ortodôntico no Centro de Reabilitação Lábio-Palatal (CERLAP da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS. Metodologia: Os dados referentes à idade, raça, gênero, tipo de fissura (pré, trans ou pós-forame incisivo, lado afetado (uni ou bilateral, agenesias e supranumerários em ambas arcadas foram avaliados a partir da documentação ortodôntica constituída por radiografias panorâmicas, cefalométricas, oclusais e periapicais, modelos de estudo e fotografias intra e extrabucais obtidas no início do tratamento, fornecendo informações necessárias para diagnóstico de anomalias dentárias. Os dados coletados foram registrados em planilhas. Resultados: A média de idade dos pacientes foi de 13. 5 anos; 86% eram brancos; e 57% eram meninos. Fissuras transforame incisivo demonstraram-se mais frequentes (83%; o lado esquerdo foi mais afetado (48. 5%. Agenesias foram encontradas em 66. 5% dos pacientes. Incisivos laterais superiores foram os dentes mais ausentes (78. 5%. Supranumerários foram encontrados em 35. 5 % dos pacientes. Conclusão: Meninos demonstraram maior tendência a apresentar fissuras e a manifestar agenesias dentárias e supranumerários. As fissuras completas de lábio e palato prevaleceram e os incisivos laterais superiores foram os dentes mais ausentes. Os supranumerários localizaram-se distalmente à fissura na maioria dos casos

  19. Creative Industries and New Materials: Challenges for Fashion and Material Industries in Global Value Chains

    OpenAIRE

    Scheffer, M. (Michiel)

    2006-01-01

    Op 27 januari 2006 is dr. Michiel Scheffer geïnstalleerd als lector Fashion Materials Design bij Saxion in Enschede. Het lectoraat en de bijbehorende kenniskring is gericht op het versterken van de wisselwerking tussen creativiteit, technologie en economie op het gebied van mode en textiel. Deze wisselwerking moet sterker tot uiting komen in het onderwijs en dient ook in samenwerking met het bedrijfsleven tot uiting te komen in een onderzoeksprogramma. Het lectoraat is ondergebracht bij ...

  20. Der kluge Spieler und die Ethik des Computerspielens

    OpenAIRE

    Wunderlich, Ralf

    2012-01-01

    „Der kluge Spieler und die Ethik des Computerspielens“ ist eine moralphilosophische Analyse der sogenannten „Killerspiel-Diskussion“. Als Aufhänger dient der Amoklauf von Winnenden, in dessen Nachgang Diskussionen über Computerspiele, speziell solche mit gewalthaltigem Inhalt, aufkamen. In der öffentlichen Meinung wird häufig davon ausgegangen, dass das Spielen solcher Computerspiele auch in der Realität zu gewalttätigem Verhalten führt. Einige Politiker stellen diese Spiele sogar mit Kinderp...

  1. Evaluación del grado de sellado marginal y resistencia adhesiva de restauraciones de resina compuesta con adhesivo convencional en dentición primaria y definitiva

    OpenAIRE

    Monsalves Bravo, Silvia Isabel; Terrazas Soto, Pedro; Toro Urbina, Georgina; Bader Mattar, Marcelo

    2014-01-01

    El presente estudio evaluó el grado de sellado marginal y resistencia adhesiva de restauraciones de resinas compuestas confeccionadas con un sistema adhesivo de grabado y lavado en dentición primaria y definitiva. Para realizar ambos test se utilizaron 20 piezas primarias y 20 piezas definitivas. En resistencia al cizallamiento, los dientes fueron seccionados longitudinalmente y se les adhirió un cilindro de resina compuesta, utilizando la técnica adhesiva de grabado y lavado para ambas denti...

  2. Estabilidad y funcionalidad de sellantes dentales en altas temperaturas ambientales

    OpenAIRE

    Mishina, Anastasia; Mayelín Guerra, Rosa; Durán Ramos, Ivette; Sabatier, Juan D.

    2000-01-01

    Los sellantes dentales son materiales que se emplean en estomatología para sellar las fosas y fisuras oclusales de los dientes y evitar la adherencia del estreptococus mutans agente que produce la caries dental. Estos materiales se suministran en dos partes que al mezclarse producen el endurecimiento de la resina. Sin embargo, estos productos presentan dificultades para su comercialización en los países tropicales, debido a que las altas temperaturas ambientales traen problemas en...

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

    OpenAIRE

    LOVÓN QUISPE, WASHINGTON EDWARD

    2015-01-01

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

  4. Ajuste y evaluación de las constantes de regresión lineal para el análisis de dentición mixta

    Directory of Open Access Journals (Sweden)

    Jaime Fabián Gutiérrez Rojo

    2012-09-01

    Full Text Available Durante el intercambio de dentición se utilizan los análisis de dentición mixta para predecir el tamaño mesiodistal de los caninos y premolares sin erupcionar. Material y Métodos: Se revisaron 912 casos pre-tratamiento de ortodoncia y fueron 504 los que cumplieron con los criterios de inclusión. Se estimó la estadística descriptiva y las constantes de regresión lineal para la población general y por género, se compararon los valores mediante la prueba de t de Student. Resultados: Existen diferencias estadísticas significativas (P≤.01 entre las constantes de Tanaka Johnston y las obtenidas en Tepic, con excepción de la mandíbula en hombres. Al compararlos con los dientes erupcionados las constantes de Tanaka Johnston no son efectivas y las constantes de población general y género masculino si lo son. Conclusiones: El análisis de regresión lineal de Tanaka Johnston sobrestima los valores de los dientes sin erupcionar.

  5. Ajuste y evaluación de las constantes de regresión lineal para el análisis de dentición mixta

    Directory of Open Access Journals (Sweden)

    Jaime Fabián Gutiérrez Rojo

    2013-01-01

    Full Text Available Durante el intercambio de dentición se utilizan los análisis de dentición mixta para predecir el tamaño mesiodistal de los caninos y premolares sin erupcionar. Material y Métodos: Se revisaron 912 casos pre-tratamiento de ortodoncia y fueron 504 los que cumplieron con los criterios de inclusión. Se estimó la estadística descriptiva y las constantes de regresión lineal para la población general y por género, se compararon los valores mediante la prueba de t de Student. Resultados: Existen diferencias estadísticas significativas (P≤.01 entre las constantes de Tanaka Johnston y las obtenidas en Tepic, con excepción de la mandíbula en hombres. Al compararlos con los dientes erupcionados las constantes de Tanaka Johnston no son efectivas y las constantes de población general y género masculino si lo son. Conclusiones: El análisis de regresión lineal de Tanaka Johnston sobrestima los valores de los dientes sin erupcionar.

  6. Cómo evitar fracasos en prótesis dental parcial removible

    OpenAIRE

    Giraldo R, Olga Lucía

    2008-01-01

    Una prótesis dental parcial removible constituye una modalidad terapéutica para restaurar rebordes edéntulos parciales, donde una prótesis parcial fija no está indicada. La prótesis dental parcial removible, aunque es un excelente medio para reemplazar dientes perdidos, puede ser una seria amenaza para los dientes remanentes, por los posibles efectos de palanca que ejerce sobre las estructuras dentarias, cuando no se planea adecuadamente. La preservación de los dientes remanentes y la maximiz...

  7. Prevalencia de trastornos témporo mandibulares y bruxismo en Uruguay: PARTE I

    Directory of Open Access Journals (Sweden)

    Raúl Riva

    Full Text Available Resumen Objetivos: Determinar el nivel de prevalencia de Bruxismo y Trastornos Témporo Mandibulares (TTM en dos poblaciones, Montevideo e Interior, en Uruguay. Método: Se realizó un estudio descriptivo transversal a nivel nacional. El muestreo fue estratifi cado polietápico. Resultados: Las variables seleccionadas y analizadas en este primer artículo fueron: grado de apertura bucal, dolor muscular, chasquido de ATM, facetas de desgaste parafuncional, dolor de cabeza, relato de ruidos articulares, sensación de haber dormido apretando los dientes y autopercepción del stress. Se han comprobando las siguientes prevalencias globales: para TTM: 55% con al menos un síntoma, siendo más prevalente en Montevideo (57% que en el Interior (53%. Con al menos un signo clínico: 44%, siendo también mas prevalente en Montevideo (47% que en el Interior (41%. En cuanto a Bruxismo activo, ante la pregunta de tener la sensación al despertar de haber dormido apretando los dientes, se encontró una prevalencia de 30,72% en Montevideo y 23,19% en el Interior, en tanto que de ser o haber sido bruxómano a través de la valoración de las facetas de desgaste parafuncional 71,95% en Montevideo y 62,17% en el Interior. Conclusiones: Con este relevamiento hemos constatado una elevada prevalencia de TTM y Bruxismo en la población uruguaya y recomendamos la elaboración de medidas de prevención y tratamiento a nivel colectivo

  8. Posibilidad regenerativa y reparadora de estructuras dentarias de células mesenquimáticas post natales

    OpenAIRE

    Siragusa, Martha

    2014-01-01

    Objetivos: Presentar evidencias clínicas de la capacidad reparativa y de la formación de nuevos tejidos mineralizados en dientes con apices incompletamente desarrollados y diagnóstico de necrosis pulpar. Ha sido demostrado que las células pulpares adultas y las del ligamento periodontal presentan un comportamiento similar en su morfología y que la superficie cellular responde positivamente a marcadores de hueso, tejido adiposo, músculos y al estroma de tejido conectivo. La posibilid...

  9. El papel de la genética en la aparición y desarrollo de la periodontitis: II: Polimorfismos asociados a la enfermedad periodontal The role of genetics in the development and progression of periodontitis: II: Polymorphism associated to periodontal disease

    OpenAIRE

    D. Rodrigo-Gómez; A. Oteo-Calatayud; A. Alonso-Rosado; A. Bascones-Martínez

    2008-01-01

    La periodontitis es una enfermedad multifactorial que resulta de la interacción de bacterias periodontopatógenas con los mecanismos de respuesta inmune del huésped y que se caracteriza por una reacción inflamatoria que afecta al aparato de inserción del diente. Las enfermedades multifactoriales habitualmente envuelven complejas interacciones de muchos genes y factores ambientales. El tipo de variaciones genéticas involucradas en este tipo de enfermedades se denominan polimorfismos genéticos, ...

  10. Untersuchungen zur Genauigkeit digitaler intraoraler Scans

    OpenAIRE

    Benedickt, Christopher Roland

    2017-01-01

    Ziel der hier vorliegenden In-vitro-Studie war es, zu untersuchen, ob es bei digitalen int-raoralen Scans zu Verzerrungen, Streckungen, Stauchungen, Verdrillungen oder Biegun-gen, kommt. Als Prüfmodell diente ein vollbezahntes Oberkiefermodell aus einer Chrom-Kobalt-Molybdän-Legierung. Auf diesem waren die Zähne 11, 15, 24 und 26 zur Auf-nahme eines Veneers, einer Vollkrone, eines Inlays präpariert, und auf inzisalen bezie-hungsweise okklusalen Mulden der Zähne 13, 23, 17 und 27 waren Metallk...

  11. El bruxismo y su efecto en los planes de tratamiento

    OpenAIRE

    Marchioni, Aldana Pamela; Ingeniero, María José

    2017-01-01

    Muchas señales clínicas advierten el hábito excesivo de rechinar los dientes. Las señales clínicas típicas del bruxismo incluyen aumento en el tamaño de los músculos temporales y maseteros, desviación de la apertura del maxilar inferior, apertura oclusal limitada, mayor movilidad dental, abfracción cervical, fracturas de los dientes o porcelana y coronas no cementadas o prótesis fijas. Las facetas de desgaste no funcional en las superficies oclusales pueden presentarse en dientes naturales o ...

  12. Sonrisas Cool

    OpenAIRE

    Dixon, Cynthia

    2013-01-01

    La valoración de la estética dental por parte de la sociedad ha aumentado en los últimos años, pues aparentemente unos dientes más blancos y alineados tienen influencia sobre la autoestima de las personas y las relaciones profesionales. La correcta y adecuada higiene de los dientes y de la cavidad bucal, es el modo más eficaz y específico para prevenir enfermedades y mantener los dientes blancos. Actualmente el SGSSS incluye la limpieza dental en el POS y las EPS son las encargadas de prestar...

  13. Decision Management : De keuze tussen mens en machine

    NARCIS (Netherlands)

    dr. Martijn Zoet; Eline de Haan

    2015-01-01

    Wanneer een beslisarchitectuur is geformuleerd, dan is daarna vaak de vraag hoe iedere individueel gespecificeerde beslissing uitgewerkt dient te worden. Gaan we voor een beslissing elk van de onderliggende bedrijfsregels volledig specificeren? Dient er een predictive analytics engine te komen of is

  14. Wirkung mineralischer N-Düngung auf Blatterträge und Scopolamingehalte von Duboisia sp.

    Directory of Open Access Journals (Sweden)

    Oster, Sabine

    2014-09-01

    Full Text Available Duboisia wird als Rohstofflieferant für Scopolamin verwendet. Dieses Tropanalkaloid wird aus dem Blattmaterial von Duboisia Arthybriden gewonnen und dient als Wirkstoff zur Therapie der Reisekrankheit sowie als Ausgangsstoff für partialsynthetische Anticholinergika. Für die effiziente Produktion sind hohe Erträge an Biomasse bei möglichst hohem Wirkstoffgehalt wünschenswert. Eine der abiotischen Einflussgrößen ist die Stickstoffernährung. Der hier beschriebene Freilandversuch stellt den Einfluss von vier unterschiedlich hohen N-Düngungsgaben (0 kg N/ha, 100 kg N/ha, 200 kg N/ha, 100+100 kg N/ha mit Kalkammonsalpeter (KAS auf drei Genotypen dar. Die N-Düngung zeigte keinen Einfluss auf den Scopolamingehalt, jedoch stieg mit erhöhter N-Menge die Biomasse signifikant an.

  15. Influencia de la agenesia dental en el desarrollo de la dentición

    OpenAIRE

    Lloret García, Miriam

    2016-01-01

    La agenesia dental describe la ausencia de desarrollo de al menos un diente. Estudios recientes sugieren la relación entre determinados patrones de agenesia y retraso en el desarrollo dental, debido a algunos genes específicos. Existen diferentes métodos para evaluar la edad de desarrollo, por ello es difícil comparar en la bibliografía los estudios que relacionan desarrollo dental con agenesia, así mismo, existen diferentes variantes que dificultan la comparación de los diferentes estudio...

  16. Background information for the SER Energy Agreement for Sustainable Growth calculations. Sector Built Environment; Achtergronddocument bij doorrekening SER Energieakkoord. Sector Gebouwde omgeving

    Energy Technology Data Exchange (ETDEWEB)

    Menkveld, M.; Tigchelaar, C. [ECN Beleidsstudies, Petten (Netherlands)

    2013-09-01

    This publication is part of the support given by ECN and PBL in the development of a national energy agreement between March and September 2013 as initiated by the SER (Social and Economic Council of the Netherlands). The report gives background information on the evaluation of measures in the agreement aimed at the built environment. It is an annex of the general evaluation of PBL/ECN [Dutch] Dit rapport is geschreven als onderdeel van de ondersteuning door ECN en PBL bij het tot stand komen van het energieakkoord in de periode maart tot september 2013. Dit rapport dient als achtergrond bij de doorrekening van de maatregelen gericht op energiebesparing in de gebouwde omgeving.

  17. La hiperdontia en región de molares

    Directory of Open Access Journals (Sweden)

    George Táccio de Miranda Candeiro

    2011-12-01

    Full Text Available La hiperdontia constituye una de las anomalías más estudiadas de la dentición humana. Esa alteración representa la aparición de uno o más dientes en cantidades mayores de lo normal, que puede ocurrir en la mandíbula o maxila y de manera unilateral o bilateral. La etiología de los dientes supernumerarios puede ser explicada principalmente por hiperactividad de la lámina dentaria en la fase inicial. Es importante la detección precoz de dientes supernumerarios porque se ha visto una serie de complicaciones como los diastemas, que pueden causar en la cavidad bucal: retardo de la erupción o dientes impactados, posicionamiento inadecuado de dientes permanentes, desajuste oclusal y el desarrollo de quistes y tumores odontógenos. Así el diagnóstico es normalmente realizado a partir de un examen radiográfico convencional, principalmente la radiografía panorámica. Este trabajo tuvo como objetivo relatar 4 casos clínicos de pacientes con presencia de molares supernumerarios, que fueron atendidos en el Servicio de Radiología de la Escuela de Odontología de la Universidad Federal de Ceará.

  18. Influencia de los tratamientos microabrasivos sobre la resistencia adhesiva en dientes con fluorosis

    OpenAIRE

    Paola Mena Silva; Ana del Carmen Armas

    2015-01-01

    La búsqueda de tratamientos mínimamente invasivos y altamente estéticos para pacientes con fluorosis, ha llevado a buscar mecanismos para solucionar esta problemática, mediante la utilización de resinas como la primera opción. Sin embargo el principal problema del tratamiento, se centra en la poca adhesión debido a las características estructurales del esmalte fluorótico, en grados de fluorosis TF 1 al 3, el ácido no actúa correctamente, causando ausencia de grabado principalmente entre las e...

  19. Efecto de la pérdida prematura de molares primarios sobre la relación horizontal incisiva

    Directory of Open Access Journals (Sweden)

    Yérica M García

    2011-01-01

    Full Text Available La pérdida prematura de molares primarios predispone a maloclusiones incluyendo apiñamiento, impactación de dientes permanentes y alteración de la relación molar y canina. El objetivo del presente estudio es determinar el efecto de las pérdidas prematuras de molares primarios sobre la relación incisiva horizontal. El estudio es documental, retrospectivo y observacional. Se evaluaron los registros ortodóncicos (historias clínicas, fotografías y radiografías de 209 pacientes con edades entre 4 a 15 años. La relación incisiva horizontal se consideró normal (grupo 1 cuando hubo contacto entre en borde incisal del incisivo inferior con la cara palatina del superior, aumentada (grupo 2 cuando había distancia positiva entre ellos y negativa (grupo 3 cuando los bordes incisales se encontraban a tope o en mordida cruzada. Los datos se analizaron utilizando coeficiente Pearson (p≤0,001. El 22% (45 pacientes presentó pérdidas prematuras. La prevalencia de pérdidas prematuras no tuvo diferencia significativa entre géneros y fue mayor en el grupo de 7 a 9 años. De los pacientes con pérdidas prematuras, 6 (13,3% se clasificó en el grupo 1; 12 (26,7% en el grupo 2 y 27 (60% en el grupo 3. Hubo asociación positiva entre el número de molares perdidos y la presencia de mordida cruzada anterior, siendo la media de molares perdidos mayor (4, 7 en el grupo 3. Se demostró que las pérdidas prematuras de molares primarios tienen una relación estadísticamente significativa con la mordida cruzada anterior, siendo posible que la falta de soporte oclusal posterior favorezca el desplazamiento protrusivo de la mandíbula.

  20. Evaluación de la edad dental en niños venezolanos utilizando el método de Schour y Massler

    Directory of Open Access Journals (Sweden)

    Zapata-K

    2014-01-01

    Full Text Available Objetivo: La presente investigación pretende determinar la precisión del método propuesto por Schour y Massler para la estimación de la edad dental en un grupo de niños Venezolanos que asistió al Servicio de Ortodoncia de Interceptiva de la Universidad Central de Venezuela en el período de 2001-2011. Materiales y métodos: Se seleccionó una muestra estratifi por edad y sexo incluyendo radiografías panorámicas de alta calidad tomadas a pacientes sanos con edades de 4 a 10 años. Se determinó estadio de erupción (con barrera ósea, sin barrera ósea, en plano oclusal y formación radicular (etapas de Nolla en la muestra, comparando las medias con las tablas de Schour y Massler (ANOVA p=0.05 distribuyendo por rangos de edad. Resultados: La erupción dental fue similar a la graficada en las tablas de Schour y Massler, con un adelanto estadísticamente significavo para el incisivo central inferior y retardo para del primer premolar superior y segundo premolar inferior. La formación radicular estuvo retrasada en comparación con las tablas, siendo estadísticamente signifi\tpara las etapas fi\tde formación radicular del incisivo lateral inferior, el primer premolar superior, segundos premolares y segundo molar superior. Conclusiones: La estimación de edad dental utilizando las tablas de Schour y Massler fue apropiada en esta muestra de niños Venezolanos.

  1. Evaluación del osteocoral como material de implante en bolsas infraóseas de dientes multirradiculares

    Directory of Open Access Journals (Sweden)

    Tania Sotomayor Marín

    1999-12-01

    Full Text Available Se evalúa la eficacia del osteocoral como material de implante en el tratamiento de bolsas infraóseas en dientes multirradiculares. Se analizaron 14 pacientes que se dividieron en 2 grupos: el primero incluyó a 6 pacientes con un total de 12 defectos, los cuales se evaluaron hasta los 6 meses. El segundo, con 8 pacientes y 16 defectos, que se reevaluaron a los 12 y 24 meses. En los 2 grupos se incluyeron pacientes de ambos sexos, que fueron implantados con osteocoral (grupo estudio y con hidroxiapatita (grupo control. Se realizó reparación inicial que incluyó remoción de cálculo y pulido de la superficie dentaria, educación y motivación y evaluación del cepillado, que debía mostrar valores iguales o mayores del 80 % en la remoción de placa dentobacteriana. Posteriormente se realizó el implante mediante operación a colgajo. Se realizaron radiografías de control a los 14 días, 6 meses (para el primer grupo y 12 y 24 meses (para el segundo grupo. Se controló sistemáticamente la higiene bucal en ambos grupos. Se controlaron nuevamente los indicadores clínicos a los 6 meses para el primer grupo, y a los 12 y 24 meses para el segundo. Se observó una disminución estadísticamente significativa en el índice gingival, profundidad de la bolsa y movilidad dentaria para ambos materiales implantológicos, sin que se reportaran grandes diferencias entre éstos. Radiográficamente se observó la presencia de relleno en el defecto original, y no hubo reacciones locales adversas, por lo que se consideró efectivo el tratamiento.Effectiveness of osteocoral was assessed as material for implants at infraosseous pockets of multirooted teeth. 14 analised patients were divided into 2 groups: first, included 6 cases and 16 defects, which were evaluated ultil 6 months. Second, included 8 cases and 16 defects, evaluated at 12 and 24 months. In both groups, males and women, were included underwent to implants with osteocoral (study group and

  2. Evolución histórica del cepillo dental

    Directory of Open Access Journals (Sweden)

    Isidro de Jesús Nápoles González

    Full Text Available La higiene bucal proviene de épocas remotas. En la era primitiva el hombre empleaba sus uñas o fragmentos de madera, en la prehispánica los indígenas utilizaban la raíz de una planta o se frotaban los dientes con los dedos. Pero el cepillo de dientes tal y como hoy se conoce comenzó a utilizarse en el siglo XVII. En su diseño se han combinado diferentes tipos, tamaños y grosores de cerdas, dispuestas en distintas angulaciones para facilitar el cepillado dental. Conocer la evolución histórica del cepillo dental constituye el propósito de esta revisión. Se realizó una búsqueda exhaustiva retrospectiva automatizada en internet, utilizando el buscador Google. Para reunir la información necesaria se emplearon las herramientas para la comunicación asincrónica de gestores personales como Endnote, que facilitan el ordenamiento de las citas. Se consultaron artículos originales en revistas, informaciones en sitios web y blogs. No hubo restricciones en la selección de los materiales, ni por fecha, autores o estilos. Se revisaron textos que en sus páginas presentan referencias concernientes al tema de investigación. Consideramos que no es necesario utilizar cepillos de alta tecnología para la lograr la higiene dental. Aplicar una técnica adecuada y saber emplear el cepillo dental facilitará este proceso, para evitar enfermedades frecuentes causadas por la placa dentobacteriana (caries dentales y enfermedad periodontal, y así lograr por más tiempo la conservación dientes funcionales en la cavidad bucal.

  3. Enfermedad periodontal: ¿es factor de riesgo para parto pretérmino, bajo peso al nacer o preeclampsia?

    Directory of Open Access Journals (Sweden)

    José Luis Castaldi

    2006-04-01

    Full Text Available OBJETIVOS: Evaluar si la enfermedad periodontal (EP constituye un factor de riesgo de parto pretérmino, bajo peso al nacer o preeclampsia y si hay alguna relación entre las formas clínicas de la EP y los resultados obstétricos mencionados. MÉTODOS: Estudio analítico, transversal y prospectivo de todas las mujeres que tuvieron su parto en el Hospital Dr. José Penna, de la ciudad de Bahía Blanca, Argentina, entre el 1.º de febrero y el 18 de julio de 2003 y entre el 1.º de marzo y el 31 de mayo de 2004. A las mujeres que cumplieron los criterios de inclusión (ser mayor de 18 años, tener al menos 18 dientes, no ser diabética y que los hijos hubieran sobrevivido al parto se les practicó un examen odontológico en busca de hemorragia al sondaje, movilidad dentaria o inflamación gingival y se realizaron mediciones clínicas de la pérdida de inserción. Se calcularon las razones de posibilidades (odds ratios, RP con sus intervalos de confianza del 95% (IC95% y se ajustaron los resultados por las variables "ser fumadora" y "tener anemia". RESULTADOS: Se registraron 2 003 nacimientos, correspondientes a 1 982 partos. Se excluyeron 420 (21,2% mujeres por no cumplir los criterios de inclusión o por no poder realizárseles el diagnóstico odontológico previsto. De las 1 562 mujeres evaluadas, 809 (51,8% presentaban alguna de las afecciones buscadas; de ellas, 274 (17,5% padecían EP grave y 535 (34,3% tenían gingivitis. En total, 149 (9,5% partos fueron pretérmino, en 161 (10,3% nacieron niños con bajo peso y en 157 (10,0% se presentaron casos de preeclampsia. No se observó asociación alguna entre la EP y el parto pretérmino (RP = 1,06; IC95%: 0,74 a 1,50, el bajo peso al nacer (RP = 1,05; IC95%: 0,74 a 1,47 y la preeclampsia (RP = 0,99; IC95%: 0,70 a 1,40. El riesgo de dar a luz un niño con bajo peso al nacer en el subgrupo de fumadoras de más de 10 cigarrillos diarios fue mayor en las que tenían enfermedad periodontal grave que

  4. CHONDRICHTHYES, Knorpelfische

    Science.gov (United States)

    Goldschmid, Alfred

    Die über 1.100 Arten der Knorpelfische sind nur etwa 4% aller heute lebenden Fischarten. Ihrknorpeliges Endoskelett kann zwar verkalken, wird abernie zu Knochen umgebaut. Der Schädel besteht nur aus Neurocranium und Viscerocranium, ein Dermatocranium fehlt. Knochen findet sich nur in den Plakoidschuppen der Körperdecke. Eine Schwimmblase wie bei den Knochenfischen wird nie gebildet. Mund- und Nasenöffnungen liegen ventral; der Endolymphgang bleibt zeitlebens mit der Epidermis verbunden. Der mediale Teil der Beckenflosse der Männchen dient als Kopulationsorgan (Mixopterygium, Klasper) (Abb. 208, 209B) bei der inneren Befruchtung.

  5. Carious measurement and pulps modifications in rats undergoing habitual and cariogenic diets treated with collagenase type II

    OpenAIRE

    Kohli, Alicia; Pezzotto, Stella Maris; Poletto, Leonor; Dávila, Héctor

    2014-01-01

    El diente puede enfermar por caries, con destrucción de tejidos duros exponiéndolo a gérmenes, provocando inflamación y dolor, siendo factor de riesgo la dieta cariogénica. Nuestros objetivos fueron visualizar los componentes del órgano pulpodentinal en ratas, comparar métodos de medición de caries y observar modificaciones en pulpas sometidas a dieta cariogénica. Se utilizaron ratas endocriadas líneas “l” y “e” al destete, divididas en dos grupos (-G1 y -G2), alimentadas con balanceado rata-...

  6. Incontinencia pigmenti con defecto en la inmunidad celular

    OpenAIRE

    Zamora-Chávez, Antonio; Escobar-Sánchez, Argelia; Sadowinski-Pine, Stanislaw; Saucedo-Ramírez, Omar Josué; Delgado-Barrera, Palmira; Enríquez-Quiñones, Claudia G.

    2015-01-01

    Introducción: La incontinencia pigmenti es una enfermedad genética rara ligada al cromosoma X, letal en el varón, que afecta a todos los tejidos derivados del ectodermo, como piel, faneras, ojos, dientes y sistema nervioso central, y presenta alteraciones de grado variable en la inmunidad celular. Se caracteriza por la disminución de la melanina en la epidermis y su incremento en la dermis. Caso clínico: Se presenta el caso de una lactante de dos meses de edad con incontinencia pigmenti gr...

  7. CC City Center in Dresden; CC City Center in Dresden

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-09-01

    In the course of an optimisation process, it was attempted to meet both the requirements of a shopping mall and an administrative building. The new building is the representative administrative building of the ESAG and also houses several shops with a total floor space of 6000 m{sup 2}. (orig.) [Deutsch] In einem Optimierungsprozess wurde versucht, die Anforderungen eines Handelszentrums genauso wie die eines Verwaltungsgebaeudes zu erfuellen. Das daraus entstandene Gebaeude dient der ESAG als repraesentative Hauptverwaltung. Zusaetzlich fanden auf 6000 m{sup 2} mehrere Geschaefte Platz. (orig.)

  8. Avaliação comparativa da ultraestrutura e propriedades físicas do esmalte bovino, bubalino e humano

    Directory of Open Access Journals (Sweden)

    Bárbara C.L. Nogueira

    2014-05-01

    Full Text Available Este estudo teve como finalidade comparar a morfologia e propriedades físicas da estrutura do esmalte dos dentes bovinos, bubalinos e humanos. A análise deste tecido foi realizada por meio de microscopia eletrônica de varredura, composição mineral, microdureza e rugosidade superficial do esmalte em 41 incisivos bubalinos (Bos taurus indicus, 41 incisivos bovinos (Pelorovis antiques e 30 incisivos permanentes de humanos. Os resultados mostraram que a ultraestrutura do esmalte revela uma significativa similaridade das espécies estudadas com a encontrada em amostras humanas. No esmalte bovino e bubalino os elementos químicos que apresentaram maior concentração foram: O, Ca e P, justamente os que formam os cristais de hidroxiapatita - Ca10(PO46(OH2. Na microdureza Knoop não houve diferença estatisticamente significante entre as três espécies. Porém, a rugosidade superficial do esmalte bubalino (2,16µm ±0,23 foi significativamente maior quando comparada aos dentes humano (0,36µm ±0,05 e bovino (0,41µm ±0,07. Conclui-se que as características e propriedades do esmalte bovino e bubalino, por meio de análises e testes, apresentou uma morfologia semelhante à de humanos, arquitetura ultraestrutural similar, microdureza e composição mineral equivalente ao tecido dental humano, tornando-se modelos de referência para pesquisas.

  9. A influência da perda bilateral do primeiro molar inferior permanente na morfologia dentofacial: um estudo cefalométrico The influence of bilateral lower first permanent molar loss on dentofacial morfology: a cephalometric study

    Directory of Open Access Journals (Sweden)

    David Normando

    2010-12-01

    Full Text Available OBJETIVO: avaliar as alterações cefalométricas em pacientes com perda bilateral do primeiro molar inferior permanente. MÉTODOS: foram analisadas 68 telerradiografias laterais de pacientes de consultórios particulares. A amostra foi dividida em dois grupos pareados quanto ao sexo e idade - 34 indivíduos sem perdas (grupo controle e 34 com perda bilateral do primeiro molar inferior permanente (grupo com perda. Foram excluídos da amostra pacientes que haviam perdido outros dentes que não o primeiro molar inferior, casos de agenesia e pacientes com menos de 16 anos de idade. Buscou-se avaliar somente indivíduos que tivessem relatado a perda há pelo menos 5 anos. RESULTADOS: demonstraram que a perda bilateral do primeiro molar inferior permanente leva ao suave fechamento do ângulo GnSN (P=0,05, um giro anti-horário do plano oclusal (P=0,0001, uma suave diminuição da altura facial anteroinferior (P=0,05, uma acentuada inclinação lingual (P=0,04 e retrusão dos incisivos inferiores (P=0,03. Por outro lado, a perda bilateral do primeiro molar inferior permanente não foi capaz de influenciar a relação maxilomandibular no sentido anteroposterior (P=0,21, a quantidade de mento (P=0,45, a inclinação dos incisivos superiores (P=0,12 e a posição anteroposterior dos incisivos superiores (P=0,46. CONCLUSÃO: a perda bilateral dos primeiros molares inferiores é capaz de produzir alterações marcantes no posicionamento dos incisivos inferiores e no plano oclusal, além de uma suave redução vertical da faceOBJECTIVE: To evaluate cephalometric changes in patients after bilateral loss of lower first permanent molar teeth. METHODS: Sixty-eight lateral radiographs of patients from private practices were analyzed. The sample was divided into two groups matched for age and gender: 34 individuals without loss (control group and 34 presenting with bilateral loss of lower first permanent molar teeth (loss group. Patients who had lost teeth other

  10. 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.

  11. Mit Expertenwissen zu Aussagen über künftige Entwicklungen — der Horizon Report Higher Education

    Directory of Open Access Journals (Sweden)

    Rudolf Mumenthaler

    2014-03-01

    Full Text Available Der Horizon Report Higher Education dient auch für Hochschulbibliotheken als wichtige Referenz zur Bewertung aktueller Trends und künftiger Entwicklungen. Der Autor stellt die dem Report zugrunde liegende Methode vor, beleuchtet diese kritisch und reflektiert die Aussagekraft der Prognosen. Die Stärken des Horizon Report liegen in der breiten Abstützung, der Offenheit des Verfahrens und der Publikation sowie der Ausarbeitung der von Expertinnen und Experten ausgewählten Themen. Gewisse Schwächen sieht der Autor in der Abhängigkeit von anderen Trendstudien sowie beim Auswahlverfahren der Trendthemen.

  12. Opiniones y creencias de embarazadas en control prenatal relacionadas con salud oral y embarazo Opinion and beliefs of pregnancy women in prenatal control related to oral health and pregnant

    OpenAIRE

    R. Fuentes Fernández; G. Oporto Venegas; A.M. Alarcón; L. Bustos Medina; R. Prieto Gómez; H. Rico Williams

    2009-01-01

    Los procesos vitales son motivo de preguntas para la humanidad. La cultura popular da respuestas a éstas, no siempre científicamente, transformando las creencias en mitos. En salud oral, se cree que las embarazadas desarrollarían caries más fácilmente que la población general, considerándose normal que "por cada hijo se pierda un diente", y mujeres embarazadas no desean recibir atención odontológica por el daño que podría producir al feto el uso de anestésicos locales, hecho importante ante l...

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

    Directory of Open Access Journals (Sweden)

    Hikmatiar Pasya

    2017-07-01

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

  14. Supernumerarios múltiples no sindrómicos: descripción de un caso

    OpenAIRE

    Trull Gimbernat, Josep M.; Banchillería Balaguer, E.; Vall-llosera Riera, J.; Gay Escoda, Cosme

    1994-01-01

    Se describe un paciente que presentaba seis dientes supernumerarios asintornáticos, cuatro de ellos rnesiodens, y se comenta el tratamiento aplicado y el resultado después de un seguimiento de 6 años. Se revisan los métodos diagnósticos, las posibilidades terapéuticas y la secuencia de las mismas así como las complicaciones de los dientes supernumerarios múltiples.

  15. Desmoplastic ameloblastoma mimicking a periapical lesion = Ameloblastoma desmoplásico mimetizando lesão periapical

    Directory of Open Access Journals (Sweden)

    Santos, Esaú Pinheiro dos

    2010-01-01

    Full Text Available Ameloblastoma desmoplásico (AD é uma rara variante do ameloblastoma, com características clínicas, imaginológicas e histopatológicas específicas. O perfil biológico deste tumor não é totalmente compreendido, devido ao número limitado de casos notificados. O objetivo deste trabalho é relatar um caso de AD simulando uma lesão periapical. Este tumor apareceu na região anterior da maxila esquerda numa paciente do gênero feminino de 24 anos de idade, entre o incisivo lateral esquerdo e o canino. A lesão era indolor e apresentava apenas um ligeiro inchaço da mucosa do palato duro. Radiograficamente, uma área radiolúcida bem delimitada que promovia a divergência radicular foi observada. O incisivo lateral respondeu negativamente aos testes pulpares. Diagnóstico provisório de cisto radicular versus cisto fissural foi estabelecido e enucleação cirúrgica seguida de curetagem foi realizada. O exame histológico das amostras revelou a proliferação dos ninhos e cordões de epitélio odontogênico comprimido imersos em um estroma densamente colagenizado, associada a um trabeculado ósseo levemente irregular. Estas características eram consistentes com AD. A necrose pulpar do incisivo e o aparecimento radiográfico atípico, deixava a doença em absconso. Apesar das altas taxas de recorrência, nenhum sinal clínico ou radiográfico de recidiva do tumor foi detectado um ano mais tarde

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

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  17. 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

  18. Pulpitis irreversible como forma de presentación de un odontoma

    OpenAIRE

    Berástegui, Esther; Buenechea Imaz, Ramón

    1997-01-01

    Se presenta un caso de odontoma compuesto que provocó pulpitis irreversible en el incisivo central superior derecho (1,1) en una joven de 20 años. El tratamiento fue la biopulpectomía total y extirpación quirúrgica del tumor.

  19. Verlies van (thuis en haard. Het belang van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding binnen het Vluchtelingenwerk, regio Utrecht

    Directory of Open Access Journals (Sweden)

    Birgit Hoogenberk

    2014-06-01

    Full Text Available Loss of home and house. The importance of loss counseling as a part of refugee social supportIn this article it is advocated that it is important that the implementation of loss counseling is part of social support for refugees, also called integrative eclectic working. Social support from VluchtelingenWerk, also known as Refugee Council, is about supporting the client in an effective manner with their personal problems which can hinder their integration. Because the target group of VluchtelingenWerk is a group of people whom have suffered many losses, attention should be brought to this subject. Unfortunately in current work methods there is no room for loss counseling, partly due to the lack of methodological tools. The losses associated with this group have a lot of impact on their daily lives and often are the source of functional limitations. By offering loss counseling and multi-method grief counseling, volunteers and employees are offered tools to make loss more negotiable. In this article different examples will be discussed and the new loss model of Stroebe and Schut will be explained. What will be clarified is the importance of the implementation of loss counseling, for the well-being and the integration process of clients as well as achieving organizational goals.Verlies van (thuis en haard. Het belang van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding binnen het VluchtelingenWerk, regio UtrechtIn dit artikel wordt gepleit voor het implementeren van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding, er is sprake van integratief eclectisch werken. De maatschappelijke begeleiding van het VluchtelingenWerk heeft als taak de cliënt zo goed mogelijk te begeleiden bij persoonlijke problemen die de inburgering kunnen belemmeren. Aangezien de doelgroep van het VluchtelingenWerk bestaat uit mensen die ontzettend veel verliezen hebben geleden dient hier aandacht voor te zijn. Helaas is in de huidige

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

    Science.gov (United States)

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

    2018-06-01

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

  1. 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.

  2. 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

  3. Aplicación de Microscopia Electrónica y Radiación Sincrotrón al Estudio de Materiales y Procesos Avanzados para la Salud y la Estética Dental

    OpenAIRE

    Ortiz Alías, Pilar

    2012-01-01

    La salud de los dientes y la cavidad bucal se encuentra relacionada con la salud y bienestar general, suponiendo un problema económico importante debido a su alto coste y los largos periodos de tiempo que requiere. Des del punto de vista científico, el cuidado oral es un campo multidisciplinario donde científicos de distintas especialidades contribuyen en el desarrollo de nuevos conocimientos y objetivos. En el presente trabajo, los estudios han sido desarrollados en el área de Química Analít...

  4. El método de elementos finitos como alternativa en el cálculo de engranajes

    Directory of Open Access Journals (Sweden)

    Roberto José García Martín

    2002-01-01

    Full Text Available A pesar de que la optimización y el diseño racional de los engranajes han sido temas de muchas investigaciones, aún siguen siendo del interés de muchos especialistas y estudiosos de los engranajes. Las razones fundamentales para este hecho están condicionadas en primer lugar a que el diseño de un engranaje es en extremo complejo debido al número de variables, limitaciones y relaciones que involucra, y por otro lado existe la particularidad de que para cada caso de optimización la función objetivo, las restricciones y las variables independientes son generalmente diferentes. En los últimos años los nuevos sistemas de computación para auxiliar al diseño (CAD han sido empleados como alternativas para el cálculo de los engranajes, pero la variedad de sistemas y las amplias posibilidades de generación de modelos matemáticos empleados en la evaluación de esfuerzos y deformaciones requieren de una validación de sus resultados a partir de cotejarlos con los procedimientos y normas establecidos por la práctica y la experiencia de años. Es conocido que los resultados de los nuevos sistemas CAD con implementación del método de elementos finitos son generalmente muy dependientes de la forma de generación de los modelos de piezas y conjuntos diseñados por complicados procedimientos, que son tratados cuál una caja negra por los proveedores de estos potentes programas y sistemas en el mercado de la informática. En este sentido, el presente trabajo pretende contrastar los esfuerzos obtenidos mediante el empleo de dos de los más potentes sistemas CAD dirigidos a la aplicación del método de los elementos finitos, como son el Solid Edge y el Cosmo Edge, con los procedimientos de cálculo derivados de las vigentes normas ISO para evaluar la capacidad de carga de los engranajes cilíndricos. En el trabajo se exponen las bases del método de generación del perfil de los dientes de un engranaje cilíndrico de dientes rectos, un algoritmo

  5. Consejos de exfumadores (Tips From Former Smokers) – Felicita

    Centers for Disease Control (CDC) Podcasts

    2014-07-07

    Felicita empezó a fumar a los 12 años. No sabía que fumar podría dañar sus encías y dientes. Perdió todos sus dientes a los 50.  Created: 7/7/2014 by Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion.   Date Released: 7/7/2014.

  6. Habitus ist Macht – politische Partizipation in Parteien

    Directory of Open Access Journals (Sweden)

    Anna-Katharina Meßmer

    2013-03-01

    Full Text Available Der demografische und strukturelle Wandel der Gesellschaft macht auch vor Parteien nicht halt: Offener und diverser müssen ihre Strukturen werden, um den zunehmenden Mitgliederrückgang auszugleichen. Dieser Beitrag untersucht, inwieweit neue Formen der Partizipation und Maßnahmen zur Diversitätsförderung im Kontext sozialer Ungleichheiten wirken können. Dabei soll in der Analyse berücksichtigt werden, wie Parteistrukturen für bislang exkludierte Mitglieder geöffnet werden können. Als Beispiel dient dabei die Sozialdemokratische Partei Deutschlands (SPD, welche sich selbst 2011 per Parteireform einen Wandel hin zur „modernsten Partei Europas“ verordnete. Analysiert wird u. a., welche Inklusions- und Exklusionsbedingungen sich möglicherweise fortschreiben und somit marginalisierte Gruppen weiterhin vom Eintritt und Aufstieg in der SPD abhalten. Als theoretischer Rahmen dienen dabei Geschlechter- und Ungleichheitstheorien.

  7. Background information for the SER Energy Agreement for Sustainable Growth calculations. Sectors Industry, Agriculture and Horticulture; Achtergronddocument bij doorrekening Energieakkoord. Sectoren industrie en land- en tuinbouw

    Energy Technology Data Exchange (ETDEWEB)

    Wetzels, W. [ECN Beleidsstudies, Petten (Netherlands)

    2013-09-01

    On September 4, 2013, representatives of employers' associations, trade union federations, environmental organizations, the Dutch government and civil society have signed an Energy Agreement for Sustainable Growth. ECN and PBL have been asked to evaluate this agreement. This report gives background information on the evaluation of the measures aimed at improving energy efficiency in industry and agriculture [Dutch] Op 4 september 2013 is het 'Energieakkoord voor duurzame groei' getekend. ECN en PBL zijn gevraagd het akkoord te beoordelen en door te rekenen. Dit rapport dient als achtergronddocument bij de doorrekening van de maatregelen gericht op energiebesparing in de industrie en land- en tuinbouw.

  8. Background information on the estimation of short-term effects of the Energy Agreement for Sustainable Growth on renewable energy; Toelichting inschatting korte-termijneffecten Energieakkoord op hernieuwbare energie

    Energy Technology Data Exchange (ETDEWEB)

    Hekkenberg, M.; Londo, H.M.; Lensink, S.M. [ECN Beleidsstudies, Petten (Netherlands)

    2013-09-01

    On September 4, 2013, representatives of employers' associations, trade union federations, environmental organizations, the Dutch government and civil society have signed an Energy Agreement for Sustainable Growth. ECN and PBL have been asked to evaluate this agreement. This report gives background information on the evaluation of the measures aimed at improving energy efficiency in industry and agriculture [Dutch] Op 4 september 2013 is het 'Energieakkoord voor duurzame groei' getekend. ECN en PBL zijn gevraagd het akkoord te beoordelen en door te rekenen. Dit rapport dient als achtergronddocument bij de doorrekening van de maatregelen gericht op energiebesparing in de industrie en land- en tuinbouw.

  9. Estudio de brackets autoligables mediante microscopía electrónica de barrido.

    OpenAIRE

    González Ruiz, Aiala

    2015-01-01

    Desde finales del siglo XIX, cuando Angle desarrolló el arco E en su afán de mover los dientes en los tres planos del espacio, se han ido creando diferentes tipos de brackets. Así, a día de hoy tenemos lo que conocemos como brackets preajustados, que llevan la información de 1º, 2º y 3er orden en su estructura interna para evitar las dobleces de los arcos. Sin embargo, el afán de los últimos años ha sido el reducir al mínimo la fricción creada entre bracket y ligadura, y por ello han surgido ...

  10. Marcadores de inmunorrespuesta en la periodontitis juvenil

    Directory of Open Access Journals (Sweden)

    Amparo Pérez Borrego,

    2002-12-01

    Full Text Available La periodontitis juvenil es una enfermedad del periodonto propia de adolescentes y adultos jóvenes, afecta principalmente los primeros molares y los incisivos y se caracteriza por la pérdida severa del hueso alveolar alrededor de dientes permanentes sin correspondencia entre la rapidez y severidad de la destrucción con los factores locales. En la causa de la enfermedad se citan factores genéticos, infecciosos e inmunológicos. Estudiamos algunos marcadores de inmunorrespuesta en 6 adolescentes que acudieron a nuestro servicio con el diagnóstico de periodontitis juvenil, además de su valoración clínica y radiológica. Ambos sexos se afectaron por igual, la movilidad dentaria y el sangramiento al sondeo fueron los hallazgos clínicos más relevantes y el índice de higiene bucal fue adecuado en todos los casos. No encontramos homogeneidad en las alteraciones inmunológicas, pero todos los pacientes estuvieron afectados en más de un marcador. Predominaron las alteraciones funcionales de linfocitos T en los estudios celulares. La hipogammaglobulinemia y la IgM elevada fueron las alteraciones más frecuentes en la inmunidad de anticuerpos. Se señala la dificultad que aún existe para explicar la patogenia de la enfermedad basándose solamente en un único factor de riesgo, así como la importancia de la valoración individual de cada enfermo.Juvenile periodontitis is a disease of the periodontium inherent to adolescents and young adults, affecting mainly the first molars and incisives and characterized by the severe loss of the alveolar bone sorrounding the permanent teeth with no correspondance between the celerity and severity of the destruction and the local factors. Genetic, infectious and immunological factors are considereed as the causes of the disease. Some immunoresponse markers were studied in 6 adolescents that were seen at our service with the diagnosis of juvenile periodontitis in addition to their clinical and radiological

  11. Mophologic Analysis of the teeth and his relation with the slaughter age of buffalos ANÁLISE MORFOLÓGICA DOS DENTES E SUA RELAÇÃO COM A IDADE DE ABATE DE BÚFALOS

    Directory of Open Access Journals (Sweden)

    Francisco Carneiro Lima

    2008-07-01

    que os dentes incisivos apresentavam-se compostos por quatro pares, dispostos em semicírculo, denominados primeiro par (pinças, segundo par (primeiros médios, terceiro par (segundos médios e quarto par (cantos. Evidenciaram-se duas dentições – decídua e definitiva –, com formas e tamanhos variados, e variáveis níveis de desgaste dentário, além da presença de ranhuras longitudinais na superfície dos dentes decíduos e definitivos, com uma coloração variando de marrom-claro a escuro. Com a análise dentária, distinguiram-se cinco grupos de animais abatidos no Estado do Maranhão, sendo que os grupos de animais menores de 2,5 anos e maiores de 5,5 anos foram os mais freqüentemente observados. Após avaliação morfológica e cronológica dos dentes incisivos de búfalos, conclui-se que os búfalos apresentam uma morfologia dentária semelhante à de outros ruminantes e que, com base na observação dentária, os búfalos abatidos no Estado do Maranhão não seguem padrão zootécnico definido para descarte.

     

    PALAVRAS-CHAVES: Abate, anatomia, búfalos, dentes.

  12. Método para la estimación del número de enterramiento en un sitio funerario

    Directory of Open Access Journals (Sweden)

    Luis R Toribio Suárez¹

    1996-08-01

    Full Text Available La estimación del número de individuos inhumados en un sitio funerario, constituye uno de los grandes problemas de la arqueología. La información que pueden darnos los dientes, si se tiene en cuenta que las estructuras mejor conservadas del material esqueletal recolectado, es aprovechada en este trabajo mediante un análisis de los valores de variabilidad y asimetría de los caracteres odontoscópicos: tubérculo de Carabelli en M¹, incisivos superiores en forma de pala, desarrollo del hipocono en M¹ y el patrón de cúspides del M¹, así como de los datos odontométricos. Ambos análisis se hicieron en la dentición permanente de una muestra de estudiantes, clasificados como europoides. Se desarrolla un método de estimación paso a paso, prefijando los niveles de confiabilidad odontoscópica y odontométrica, que además, considera las estimaciones de las edades de los especímenes hallados en un sitio funerario.The estimation of the number of individuals buried in a funerary site constitutes one of the most problemic aspects of archaelogy. The information provided by the teeth, taking into account that they are the best preserved structures of the skeletal material collected, is used in this work through the analysis of the values of variability and asymetry of odontoscopic aspects such as Carabelli's tubercule in M1, upper shovel-shaped incisors, development of hypocone in M 1, and the cusp pattern in M 1, and odontometric data. Both analysis were made for the permanent identification of a sample made up by students classified as caucasoids. A step-by step estimation method is developved fixing the levels of odontoscopic and odontometirc confidence, which in addition considers age estimations of all specimens found in the funerary site.

  13. 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

  14. 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.

  15. Caracterización clínico epidemiológica del bruxismo en pacientes mayores de 15 años

    Directory of Open Access Journals (Sweden)

    Antonio Leyva Ponce de León

    2015-11-01

    Full Text Available Se realizó un estudio descriptivo de corte transversal, con el objetivo de caracterizar clínica y epidemiológicamente el bruxismo en pacientes mayores de 15 años, en el consultorio No. 6, perteneciente al Área de Salud del Policlínico “Romárico Oro Peña”, municipio de Puerto Padre. Se interrogó y se examinó a toda la población incluida en el estudio para determinar las características de esta afección. El grupo más afectado fue el de 25 a 34 años. Se observó un ligero predominio de pacientes del sexo femenino. Referido a la ocupación los más afectados fueron los intelectuales, seguidos de los trabajadores. Según forma de bruxismo y el horario en el que practican este hábito, se aprecia que el rechinamiento estuvo presente en la totalidad de los pacientes, en el horario nocturno, seguido del apretamiento durante el día. En cuanto a los síntomas prevaleció el dolor y cansancio muscular, seguido de los que presentaron fracturas de dientes y restauraciones. El signo más frecuente fue la existencia de patrones no funcionales de desgaste oclusal, seguido de la fractura de dientes y restauraciones.

  16. 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.)

  17. Erupción dentaria: estudio radiográfico de corredores de erupción de caninos superiores en niños con 10 años de edad.

    Directory of Open Access Journals (Sweden)

    Fernando Aguilera Zurira

    2014-12-01

    Full Text Available Las características anatómicas del canino superior lo convierten en el diente con mayor potencial de supervivencia en la arcada. Desde un punto de vista funcional, los caninos son considerados dientes claves en la oclusión. Con un gran protagonismo estético, dan armonía al frente anterior y la línea de la sonrisa. La erupción de los caninos superiores debe ser observada con frecuencia ya que es el diente en segundo lugar que presenta alteraciones en su erupción después de los terceros molares, este seguimiento se debe realizar con observaciones clínicas como radiográficas para tener la posibilidad de ir guiando el trayecto de erupción. Desde los 8 a 10 años de edad empieza a palparse la prominencia del canino en el fondo del vestíbulo. Si no se palpa a los 10 años, está indicado realizar un estudio radiológico para valorar la posición y reabsorción radicular del canino temporal. En este trabajo se realizó un estudio descriptivo en radiografías panorámicas en niños con 10 años de edad de ambos sexos de la ciudad de Quito, con el objetivo de analizar los corredores de erupción de caninos superiores, así como observar e interpretar la situación de los caninos superiores y su relación con las estructuras vecinas, describir las curvas y columnas de erupción en caninos superiores, para determinar si existe alteraciones y diferencias en cuanto a la erupción de los caninos definitivos en relación al sexo de los niños evaluados. La muestra estuvo constituida por 60 niños (30 hombres y 30 mujeres. De este grupo en cuanto a corredores de erupción se estableció que un 12% corresponde a curvas entrelazadas y un 7% a interrumpidas, estableciendo que el control clínico es fundamental y el seguimiento radiográfico secuencial permitirá ir revisando la evolución de la erupción de los caninos superiores y estructuras adyacentes. En cuanto a las columnas de erupción se determinó que el 2% de la muestra se encuentra en la

  18. Proton irradiation studies on Al and Al5083 alloy

    Science.gov (United States)

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

    2017-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Zaenuddin Mansyur

    2012-06-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

  1. The effects of boron in TiAl/Ti3Al

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohammed Shahien

    2011-10-01

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

  3. Defectos del esmalte, caries en dentición primaria, fuentes de fluoruro y su relación con caries en dientes permanentes Enamel defects, caries in primary dentition and fluoride sources: relationship with caries in permanent teeth

    Directory of Open Access Journals (Sweden)

    Ana Alicia Vallejos-Sánchez

    2007-06-01

    Full Text Available Objetivo: Explorar la relación entre la presencia de defectos del esmalte (DE, la experiencia de caries en la dentición temporal, y la exposición a diversas fuentes de fluoruros, con la presencia de caries en la dentición permanente de niños con dentición mixta. Material y métodos: Se realizó un estudio transversal en 713 sujetos de 6-9 años de edad de 4 escuelas de Campeche, México, mediante un cuestionario dirigido a las madres, y un examen clínico bucal a los niños. La variable dependiente fue la prevalencia de caries en la dentición permanente. Resultados: El promedio de dientes temporales cariados, extraídos y obturados (ceod y dientes permanentes cariados, perdidos y obturados (CPOD fue de 2,48 (2,82 (ceod > 0 = 58,9% y 0,40 (0,98 (CPOD > 0 = 18,2%, respectivamente. El índice SiC (índice de caries significativa, calculado en la dentición temporal fue de 5,85 para los niños de 6 años de edad. En el análisis de regresión logística multivariado permanecieron significativas, después de ajustar por variables de exposición a fluoruros, la mayor edad (odds ratio [OR] = 2,99, el ceod > 0 (OR = 5,46, la menor escolaridad de la madre (OR = 1,57 y una interacción entre sexo y defectos del esmalte. Conclusiones: Las caries en la dentición temporal y permanente fueron relativamente menores que las observaciones publicadas por otros estudios en México. Los resultados confirmaron que la caries en la dentición temporal se asoció fuertemente con la caries en la dentición permanente. No hubo una relación significativa entre las fuentes de fluoruro y la caries dental en la dentición permanente.Objective: To examine the relationship between the presence of enamel defects, dental caries in primary teeth, and exposure to various fluoride technologies and the presence of dental caries in permanent teeth in children with mixed dentition. Materials and methods: A cross-sectional study was conducted in 713 children aged 6-9 years old

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

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  5. 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.

  6. Estilos de vida saludables de niños, niñas y adolescentes

    Directory of Open Access Journals (Sweden)

    Lilia Campo-Ternera

    2017-01-01

    Full Text Available Objetivo: Describir los estilos de vida saludables de niños, niñas y adolescentes de Barranquilla. Materiales y métodos: Estudio descriptivo de corte transversal en 991 niños, niñas y ado - lescentes. Se evaluó la actividad física mediante los cuestionarios de Actividad Física para Adolescentes y para niños escolares; se aplicó una encuesta que midió los conocimientos y prácticas de los escolares sobre salud bucal, lavado de manos, consumo de frutas y verduras y cuidado postural; la Lista de Chequeo “Mi Vida en la Escuela”, la cual evalúa los índices de “bullying” y agresión; y la inteligencia emocional a través dela escala TMMS -24. Resultados: El 65,4 % se categoriza como inactivos físicamente. Solo el 14,7% de los estudiantes reconoce que el peso máximo del bolso es el 10 % de su peso corporal; el 34,1 % cambia el cepillo de dientes cada 3 meses, como lo recomiendan los expertos, y 48,4 % se cepilla los dientes entre 2 y 3 veces al día. El 16,6 % no se lava las manos antes y después de ir al baño y 9,4 % no lo hace antes y después de las comidas; el 17,5 % no tiene un buen consumo de verduras y frutas; y se encontró un Índice de “bullying” en el 55,6 % de los participantes. Conclusión: Los anteriores resultados obligan a plantear intervenciones que incrementen las prácticas saludables en niños, niñas y adolescentes.

  7. Acción antimicrobiana de extracto etanólico de propóleos sobre estreptococos mutans

    Directory of Open Access Journals (Sweden)

    Patricia Alejandra Vaculik

    2014-12-01

    Full Text Available El propóleo es un producto natural, posee una amplia variedad de propiedades vinculadas a las ciencias de la salud. De acuerdo al lugar de origen, condiciones climatológicas y tipo de especies botánicas circundantes, son las características que va a reunir. Por ello la particularidad de conocer el tipo de propóleos de nuestra zona geográfica y las propiedades que posee de acuerdo a sus compuestos químicos. La caries dental es una enfermedad infecciosa, que se origina por la interacción de múltiples factores, la dieta, el diente susceptible, los microorganismos, tiempo y la edad. Entre los microorganismos implicados en la formación de caries encontramos al Estreptococos mutans. El objetivo de este trabajo es conocer el propóleo de nuestra región y sus efectos antimicrobianos sobre los Estreptococos mutans.

  8. Celulitis facial iatrogénica como consecuencia de una sepsis odontógena

    Directory of Open Access Journals (Sweden)

    Martha Betancourt Pérez

    2013-08-01

    Full Text Available Se describe el caso clínico de un paciente de 56 años de edad, quien perdiera la obturación del canino superior derecho y acudió al servicio estomatológico de la Clínica Estomatológica Provincial Docente "Mártires del Moncada" de Santiago de Cuba con intenso dolor y sepsis apical incipiente, ante lo cual pedía una nueva obturación para aliviar sus síntomas. La especialista detectó la infección en ciernes y le alertó sobre las posibles complicaciones, pero debido a la insistencia del afectado obturó nuevamente el diente; en consecuencia, a las pocas horas se desarrolló una aguda celulitis facial con afectación periorbitaria, que solo cedió al administrar antibióticos de amplio espectro por vía endovenosa.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  10. 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

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

    OpenAIRE

    Gediminaitė, Barbora

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kerwanto Kerwanto

    2014-12-01

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

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

    International Nuclear Information System (INIS)

    Ma Xiaoguang; Liu Xiangfa; Ding Haimin

    2009-01-01

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

  14. Enfermedad periodental y nutrición

    OpenAIRE

    Abascal, Micaela

    2015-01-01

    Aunque no ponen en peligro la vida, las enfermedades dentales tienen un efecto pernicioso en la calidad de vida desde la infancia hasta la ancianidad, pues influyen en la autoestima, la capacidad para alimentarse, la nutrición y la salud. La salud bucal significa algo más que dientes en buen estado ,donde el estado nutricional cumple un rol importante dado que afecta a los dientes antes de que broten, aunque esa influencia es mucho menos importante que el efecto local de la die...

  15. Diseño y operación racional de engranajes cilíndricos orientado a aumentar la eficiencia y disminuir pérdidas por fricción

    OpenAIRE

    González Rey, Gonzalo; García Toll, Alejandra; García Domínguez, María E.

    2009-01-01

    Los engranes cilíndricos constituyen transmisiones mecánicas de elevada eficiencia pero los actuales requerimientos de lograr aún una eficiencia mayor hacen necesario una precisión en los procedimientos de cálculo de pérdidas de potencia. Los Reportes Técnicos ISO/TR 14179-1:2001 e ISO/TR 14179-2:2001 ofrecen importantes relaciones empíricas y teóricas para evaluar la eficiencia de los engranes considerando perdidas por rozamiento en el contacto diente- diente, por batimie...

  16. Síndrome de Cockayne: Informe de un caso: revisión de la literatura

    OpenAIRE

    Arenas Sordo, María de la Luz; Hernández Zamora, Edgar; Montoya Pérez, Luis A.; Aldape Barrios, B.

    2006-01-01

    El Síndrome de Cockayne (CS) es un desorden genético con un patrón de herencia autosómico recesivo que fue descrito por primera vez en 1936 por Cockayne. Los pacientes con este síndrome presentan detención del crecimiento, talla baja, envejecimiento prematuro, anormalidades neurológicas, fotosensibilidad, retraso en la erupción de los dientes primarios, ausencia congénita de dientes permanentes, macrodoncia parcial, atrofia de los procesos alveolares y caries dental. Puede ser causado por mut...

  17. Cockayne?s Syndrome : A case report. Literature review

    OpenAIRE

    Arenas Sordo, María de la Luz; Hernández Zamora, Edgar; Montoya Pérez, Luis A.; Aldape Barrios, B.

    2006-01-01

    El Síndrome de Cockayne (CS) es un desorden genético con un patrón de herencia autosómico recesivo que fue descrito por primera vez en 1936 por Cockayne. Los pacientes con este síndrome presentan detención del crecimiento, talla baja, envejecimiento prematuro, anormalidades neurológicas, fotosensibilidad, retraso en la erupción de los dientes primarios, ausencia congénita de dientes permanentes, macrodoncia parcial, atrofia de los procesos alveolares y caries dental. Puede ser causado por...

  18. Síndrome de Cockayne: Informe de un caso. Revisión de la literatura

    OpenAIRE

    Arenas Sordo, María de la Luz; Hernández Zamora, Edgar; Montoya Pérez, Luis Alberto; Aldape Barrios, Beatriz Catalina

    2006-01-01

    El Síndrome de Cockayne (CS) es un desorden genético con un patrón de herencia autosómico recesivo que fue descrito por primera vez en 1936 por Cockayne. Los pacientes con este síndrome presentan detención del crecimiento, talla baja, envejecimiento prematuro, anormalidades neurológicas, fotosensibilidad, retraso en la erupción de los dientes primarios, ausencia congénita de dientes permanentes, macrodoncia parcial, atrofia de los procesos alveolares y caries dental. Puede ser causado por mut...

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  20. 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.

  1. La psicología, la ética y los derechos humanos

    OpenAIRE

    Constaín Mosquera, César

    2010-01-01

    Se lo que es la psicología; con su ejercicio me gano modestamente la vida y ejerzo una vocación. La ética me acompaña desde hace muchos años, me obliga a andar derecho, a no dejar crecer en forma desmedida mi cuenta bancaria, me mantiene libre de sentimientos de culpa y hace que todos los días, al cepillarme los dientes, pueda mirarme en el espejo sin que me dé vergüenza. De los derechos humanos, que hoy en día están en boga, sé porque los violan por todas partes y todos los días. La psicolog...

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

    Institute of Scientific and Technical Information of China (English)

    韩延峰; 刘相法; 王海梅; 王振卿; 边秀房; 张均艳

    2003-01-01

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

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

    Science.gov (United States)

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

    2018-06-01

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

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

    OpenAIRE

    Cheng, Rong; Wu, Xiao-Yu

    2013-01-01

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

  5. Die Bedeutung des Knochenstoffwechsel-Biomarker in der Osteologie 2012

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2012-01-01

    Full Text Available In den vergangenen Jahren wurden zahlreiche Moleküle aus unterschiedlichen Knochenstoffwechselwegen – so genannte „Knochenbiomarker“ – identifiziert. Sowohl Serum und Plasma als auch Harnanalysen werden für klinische Messungen des Knochenstoffwechsels herangezogen, wobei die Genauigkeit und Nutzerfreundlichkeit Blutproben deutlich bevorzugt. Die systemische Messbarkeit dieser Labormarker außerhalb des Knochens dient dabei als Basis für einen aktuellen „Schnappschuss“ des Knochenstoffwechsels. Die Bedeutung der Knochenbiomarker 2012 liegt in der zunehmend ganzheitlichen Betrachtung von Knochenerkrankungen, wobei einzelne morphologische Messungen wie die Dual-Energie- Röntgenabsorptiometrie (DXA nicht mehr als einzige Methode zur Knochenbeurteilung herangezogen werden. Eine internationale Standardisierung der wichtigsten Knochenmarker zur besseren Vergleichbarkeit ist bereits im Laufen. Eine vereinfachte technische Umsetzung soll in den nächsten Jahren auch weniger spezialisierte Labors und Point-of-Care-Tests einschließen, wobei neue Erkenntnisse aus der Präanalytik von Bedeutung sind. Ob sich Knochenbiomarker in Zukunft weiter durchsetzen werden, hängt allerdings nicht nur von wissenschaftlichen und medizintechnischen, sondern auch von ökonomischen und demographischen Umständen ab.

  6. Die Bedeutung des Knochenstoffwechsel-Biomarker in der Osteologie 2012

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2013-01-01

    Full Text Available In den vergangenen Jahren wurden zahlreiche Moleküle aus unterschiedlichen Knochenstoffwechselwegen – so genannte „Knochenbiomarker“ – identifiziert. Sowohl Serum und Plasma als auch Harnanalysen werden für klinische Messungen des Knochenstoffwechsels herangezogen, wobei die Genauigkeit und Nutzerfreundlichkeit Blutproben deutlich bevorzugt. Die systemische Messbarkeit dieser Labormarker außerhalb des Knochens dient dabei als Basis für einen aktuellen „Schnappschuss“ des Knochenstoffwechsels. Die Bedeutung der Knochenbiomarker 2012 liegt in der zunehmend ganzheitlichen Betrachtung von Knochenerkrankungen, wobei einzelne morphologische Messungen wie die Dual-Energie- Röntgenabsorptiometrie (DXA nicht mehr als einzige Methode zur Knochenbeurteilung herangezogen werden. Eine internationale Standardisierung der wichtigsten Knochenmarker zur besseren Vergleichbarkeit ist bereits im Laufen. Eine vereinfachte technische Umsetzung soll in den nächsten Jahren auch weniger spezialisierte Labors und Point-of-Care-Tests einschließen, wobei neue Erkenntnisse aus der Präanalytik von Bedeutung sind. Ob sich Knochenbiomarker in Zukunft weiter durchsetzen werden, hängt allerdings nicht nur von wissenschaftlichen und medizintechnischen, sondern auch von ökonomischen und demographischen Umständen ab.

  7. Estudo comparativo da reabsorção radicular apical em pacientes bruxônomos e pacientes sem sinais clínicos de desgaste dentário Comparative study of apical root resorption in patients whith bruxism and without clinical signs of dental wearing

    Directory of Open Access Journals (Sweden)

    Rebeca Odebrech

    2004-05-01

    Full Text Available A reabsorção radicular, assim como o bruxismo, são temas amplamente abordados na literatura, contudo, a associação dos mesmos ainda permanece pouco documentada. Desse modo, esta pesquisa objetiva comparar pacientes portadores de bruxismo e pacientes sem sinais clínicos de desgaste dentário em relação à quantidade de reabsorção radicular apical nos incisivos superiores. Para tanto foram avaliados clínica e radiograficamente 64 pacientes, perfazendo um total de 256 incisivos acompanhados. Os resultados demonstram que há uma correlação positiva entre bruxismo e reabsorção radicular.Root resorption and bruxism are largely study in literature. However their association still remains few documented. The aim of this study is compare the quantity of apical root resorption in upper permanent incisors in patients with bruxism and without clinical signs of dental wearing. 64 patients (256 incisors were evaluated clinical and radiografically. The results shows the correlation between bruxism and root resorption.

  8. Caracterização morfológica dos dentes de mocó Kerodon rupestris: Mammalia: Rodentia

    Directory of Open Access Journals (Sweden)

    Juliana Montovani Thomaz

    2006-10-01

    Full Text Available O Kerodon rupestris, também conhecido como mocó, é um roedor herbívoro encontrado no Brasil. A dentição dos mamíferos apresenta-se variável de acordo com as espécies embora seja formada pelos mesmos componentes: esmalte, dentina, cemento e polpa. Neste estudo foram utilizadas sete cabeças de Kerodon rupestris, adultos, de ambos os sexos. Na cavidade oral do Kerodon rupestris, devido ao tamanho relativamente grande dos incisivos, estes se destacaram dos demais e foram encontrados um par em cada mandíbula. Dois pares de pré-molares e três pares de molares foram encontrados, sendo representados na fórmula 2x (I 1/1, C 0/0, P 1/1, M 3/3. Os molares apresentaram duas cúspides, conformação que conferia a estes dentes um aspecto serrilhado. Microscopicamente os dentes incisivos, pré-molares e molares foram classificados como hipsodontes, ou seja, dentes em constante erupção.

  9. Fechamento de Diastema com resina composta

    Directory of Open Access Journals (Sweden)

    Vanessa Schwarz

    2015-02-01

    Full Text Available A presença de diastemas na região de incisivos centrais e laterais superiores é considerado um fator antiestético altamente prejudicial do ponto de vista social. Os diastemas podem ser decorrentes da presença de inserção baixa do freio labial, presença de mesiodens, fatores genéticos ou mesmo estar ligado a doenças periodontais associadas ao tabagismo ou não. Contudo, podem comprometer a estética do sorriso substancialmente em função de sua extensão. Este trabalho descreve, através de um relato de caso clínico, a técnica de fechamento de diastema entre incisivos centrais e laterais superiores por meio de resinas compostas, realizado na faculdade de Odontologia da Faculdade Meridional (IMED. Concluiu-se que o uso de sistemas adesivos e resinas compostas, através de mínimas intervenções, podem proporcionar um melhor contorno aos dentes, resultando em um sorriso com aspecto mais estético e agradável.

  10. COMPARACIÓN DE LA PERCEPCIÓN ESTÉTICA DE LA SONRISA ENTRE ESPECIALISTAS DE ORTODONCIA, ESTUDIANTES DE ORTODONCIA, ODONTÓLOGOS Y LEGOS

    OpenAIRE

    García Garza, Edith Briceida

    2012-01-01

    Antecedentes: Una de las características de la estética facial que sin duda resalta a la vista es la sonrisa. Una sonrisa atractiva es fuertemente relacionada con rasgos de la personalidad como calidez, calma, extroversión, y baja ansiedad. Uno de los aspectos más importantes de la estética facial y dental es la exposición vertical anterior de los dientes. Desafortunadamente los dientes no siempre están en balance con las estructuras faciales adyacentes. Lo que puede afectar la...

  11. Consideraciones para la toma de impresión de prótesis sobre implantes

    OpenAIRE

    Pérez Pellin, Siulbel

    2008-01-01

    El diseño protésico depende de ciertas condiciones orales y hoy en día el tratamiento con implantes es un recurso terapéutico habitual en el reemplazo de dientes. Existen circunstancias que modifican el desarrollo del tratamiento implantológico y que deben ser evaluadas como son: el espacio entre las arcadas dentales, plano oclusal existente, relación y forma de las arcadas dentales, número y posición de los dientes, entre otras, que determinan la intervención interdisciplinaria del área prot...

  12. Impacto de la salud oral en la calidad de vida de la gestante

    OpenAIRE

    García-Martin, José M.; González-Díaz, Águeda; García-Pola, María J.

    2017-01-01

    RESUMEN Objetivo Identificar los factores determinantes de la calidad de vida relacionada con la salud oral (OHIP-14) en una población de mujeres embarazadas. Métodos En el estudio participaron 90 pacientes embarazadas, 45 inmigrantes y 45 españolas. Las participantes completaron el cuestionario de OHIP-14 (versión española) y se les exploró el índice CAOD (presencia de caries, ausencia de dientes por caries y dientes obturados) en el segundo trimestre de embarazo. Se realizó un estudio a...

  13. Comportamiento de proporciones divinas e índice de Bolton en mediciones dentales de individuos con maloclusión Behavior of "divine" proportions and the Bolton's index in dental measurements of subjects with malocclusion

    Directory of Open Access Journals (Sweden)

    Adriana Lorenzo Uribazo

    2011-09-01

    Full Text Available Los pacientes acuden cada vez con más frecuencia a los servicios estomatológicos en busca de mejorar su aspecto estético. Uno de los métodos más polémicos para el examen de la estética lo constituyen aquellos que se basan en el empleo de la proporción divina, esto motivó a la realización de este trabajo. Se evaluó el comportamiento de las proporciones divinas en mediciones dentales de individuos con maloclusión, mediante el empleo del índice de Bolton. Se realizó un estudio descriptivo transversal en estudiantes del segundo al quinto años de la Facultad de Estomatología de La Habana, Cuba, desde el mes de enero del año 2009 al mes de enero del año 2010. Se emplearon modelos de yeso pertenecientes a 80 estudiantes de 18 a 25 años de edad. Se efectuaron mediciones de los anchos mesiodistales de los dientes y se relacionaron algunas secciones de dientes donde se identificaron los que guardaron relación de proporción divina, según la variable oclusión. Los estudiantes que presentaron maloclusión se estudiaron según la variación del índice de Bolton. En los estudiantes con maloclusión el índice de Bolton que predominó fue a favor de un mayor tamaño de los dientes anteroinferiores, con rangos de proporción divina menores de 1,60.Patients came more and more frequently to Stomatology services to improve the esthetic feature. Among the more polemic methods for esthetics examination are those based on the use of divine proportion, leading to carrying out of present paper to assess the behavior of divine proportions in the dental measurements of subjects with malocclusion using the Bolton's index. A cross-sectional and descriptive study was conducted in second to fifth years students of the Stomatology Faculty of La Habana from January, 2009 to January, 2010 using the plaster casts in 80 students aged 18 to 25. Measurements of the mesio-distal width of teeth relating some sections of them where were identified those en

  14. /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.

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

    Directory of Open Access Journals (Sweden)

    M. Rusydi Khalid

    2017-12-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  18. 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

  19. Hipodoncia y hueso navicular accesorio: una interesante asociación sindrómica

    Directory of Open Access Journals (Sweden)

    Mario Cantín

    2012-09-01

    Full Text Available Los dientes se desarrollan a partir de múltiples interacciones recíprocas entre células del epitelio oral y el ectomesénquima. Una serie de genes participan en el desarrollo del diente, así como de otros órganos y miembros superiores e inferiores. PAX9, miembro de la familia de factores de transcripción, es uno de los principales responsables de este desarrollo, y juega un rol fundamental en la hipodoncia dental y malformaciones en los huesos del miembro inferior. El objetivo de este reporte es presentar un caso de asociación entre hipodoncia y el hueso navicular accesorio. Se trata de una paciente de 18 años de edad, que acude a la consulta dental por dolor agudo en la pieza dentaria 3.6 y dolor de 9 meses de evolución en la cara interna del pie izquierdo. Al examen radiográfico, se observó ausencia de las piezas dentarias 1.7, 2.7, 2.8, 3.8 y 4.8, además en el pie izquierdo se vio la presencia de un hueso navicular accesorio. Es interesante proponer esta rara asociación, de clara herencia autosómica dominante, dado que la agenesia dental y la presencia del hueso navicular accesorio, poseen una prevalencia semejante, lo que hace que pueda existir una nueva asociación sindrómica probablemente relacionada con la ausencia de PAX9.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-15

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

  3. Síntesis, caracterización y evaluación antimicrobiana de AgNPs, TiO2NPs, y Ag/TiO2NPs utilizando como soporte Al2O3 proveniente de brackets cerámicos

    OpenAIRE

    Morales Luckie, Raul Alberto

    2016-01-01

    En la actualidad uno de los tratamientos más solicitados en la práctica odontológica sin duda es la ortodoncia, que se encarga de mantener la relación funcional, armónica y estética del complejo dentocraneal, mediante el uso de aparatología fija y removible. El control de la placa dentobacteriana es especialmente importante durante el tratamiento ortodóntico, debido a que las áreas de los dientes que se encuentran cerca de los brackets y alambres son difíciles de limpiar con el cepillo dental...

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

    Science.gov (United States)

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

    2016-08-15

    Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share common clinical, genetic and neuropathological features. Some ALS patients have behavioral/personality changes, which could result in significant obstacles in the care provided by family members and caregivers. An easy screening tool would contribute greatly to the evaluation of these symptoms. We translated the ALS-FTD-Questionnaire, developed in the Netherlands, into Japanese (ALS-FTD-Q-J) and examined the clinimetric properties (internal consistency, construct and clinical validity). Patients with ALS and/or behavioral variant FTD (bvFTD) were evaluated alongside healthy controls in this multicenter study. All ALS patients, regardless of bvFTD status, were further evaluated by the frontal behavioral inventory (FBI) and for frontal/executive function, cognition, anxiety/depression, and motor functions. Data from 146 subjects were analyzed: ALS (92), ALS-bvFTD (6), bvFTD (16), and healthy controls (32). The internal consistency of the ALS-FTD-Q-J was good (Cronbach α=0.92). The ALS-FTD-Q-J showed construct validity as it exhibited a high correlation with the FBI (r=0.79). However, correlations were moderate with anxiety/depression and low with cognitive scales, in contrast to the original report, i.e. a moderate correlation with cognition and a low correlation with anxiety/depression. The ALS-FTD-Q-J discriminated ALS patients from (ALS-)bvFTD patients and controls. Thus, the ALS-FTD-Q-J is useful for evaluating Japanese ALS/FTD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. 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)

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

    Science.gov (United States)

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

    2014-01-01

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

  7. 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.

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

    Science.gov (United States)

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

    2017-07-01

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

  9. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Giridhar Pulletikurthi

    2015-12-01

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

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

    International Nuclear Information System (INIS)

    Watanabe, Y.; Fukui, Y.

    1997-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-25

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

  14. 27Al NMR studies of NpPd5Al2

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  15. Magnetic tunnel junctions with AlN and AlNxOy barriers

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  16. 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

  17. Mesiodens en posición inusual: reporte de un caso

    OpenAIRE

    Martha Rebolledo-Cobos; Manuel Escalante-Fontalvo

    2015-01-01

    Los dientes supernumerarios son alteraciones medianamente frecuentes que aparecen en cualquier área de los arcos dentales y pueden afectar a cualquier órgano dentario anterior, también llamado mesiodens. Esta alteración clínicamente presenta erupción retardada e inclusión de dientes permanentes, apiñamiento, diastemas, mal oclusión y en casos más complejos se pueden encontrar a nivel de piso de fosas nasales o incluídos en el seno maxilar, la mayoría de veces son asintomáticos. Las radiografí...

  18. Abordaje odontopedátrico de un paciente con Displasia Ectodérmica

    Directory of Open Access Journals (Sweden)

    Juan Diego Mejía Roldan

    2015-01-01

    Full Text Available La Displasia Ectodérmica hace parte un grupo de afecciones o síndromes, que tienen en común defectos en el desarrollo normal de dos o más tejidos derivados del ectodermo, en los cuales hay un desarrollo anormal de la piel, dientes, pelo, uñas o glándulas sudoríparas. Presenta oligodoncia, dientes en clavija y reabsorción de procesos alveolares, se le realizó un tratamiento integral odontológico, consiguiendo una estética, funcionalidad y adaptación excelente así como una considerable mejora de la autoestima.

  19. Opciones de tratamiento en un paciente con pérdida prematura de segundos molares primarios: zapato distal modificado / Treatment Options in a Patient with Primary Second Molar Premature Loss: Modified Distal Shoe Space Maintainer

    OpenAIRE

    Cardoso, María Lorena; Universidad Nacional del Nordeste. Corrientes, Argentina; Falcón, Diana Emilia; Universidad Nacional del Nordeste. Corrientes, Argentina; Galiana, Andrea Verónica; Universidad Nacional del Nordeste. Corrientes, Argentina

    2017-01-01

    RESUMEN. Antecedentes: La pérdida prematura de un molar primario conlleva a malposición de los dientes contiguos y del sucesor permanente. El efecto depende de las fuerzas que actúan sobre el diente, que están condicionadas a su vez por el estado de erupción del primer molar permanente. Propósito: Describir una opción de tratamiento para la pérdida prematura de segundos molares primarios hasta la erupción de los primeros molares permanentes. Descripción del caso: El caso clínico presentado in...

  20. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

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

  1. Evaluación radiográfica y microscópica de la acción de quelantes en la remoción del barro dentinario

    Directory of Open Access Journals (Sweden)

    Janet Ofelia Guevara Canales

    Full Text Available Introducción: el tratamiento endodóntico realiza la limpieza y conformación del sistema de conductos radiculares, ya que virutas de dentina y materiales orgánicos, como los microorganismos, creadas por la acción de la instrumentación, forman el llamado barro dentinario. Objetivo: evaluar in vitro la remoción del barro dentinario y la disminución de la densidad de túbulos dentinarios, con soluciones irrigadoras quelantes. Métodos: se trata de un estudio experimental para el cual fueron seleccionados 30 dientes unirradiculares de humanos después del examen radiográfico inicial, y en el que se constató la presencia de canal único, ausencia de calcificación, reabsorción interna y tratamiento endodóntico concluido o en proceso. Luego se procedió a la instrumentación con tres diferentes soluciones irrigadoras: ácido etilenodiaminetetracético 17 %, ácido cítrico 10 % e hipoclorito de sodio 5,25 % (grupo control. Posteriormente se evaluó radiográficamente cada diente instrumentado con el uso de una escala de densidad que fue confeccionada de aluminio con diferentes marcadores de densidades. Para el análisis por microscopio electrónico de barrido se utilizaron tres dientes de cada grupo, tratados con diferentes soluciones irrigadoras. Siete dientes de cada grupo se infiltraron con azul de metileno para la lectura de la infiltración marginal en el microscopio estereoscópico. Los dientes fueron evaluados en sus tres tercios: cervical, medio y apical. Resultados: se encontró que radiográficamente no hubo diferencia estadísticamente significativa entre los promedios de las densidades de los grupos de dientes en todos los tercios. Por microscopio electrónico de barrido se encontró una diferencia estadísticamente significativa entre los tres grupos de sustancias irrigadoras (p < 0,001, en el tercio cervical la remoción del barro dentinario fue mayor. Y por microscopio óptico se observó una mayor infiltración en el grupo

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    MOHD HAIDHAR KAMARZAMAN

    2016-12-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  5. Distribución de la caries dental en niños preescolares en una región urbana, Argentina, 1992

    Directory of Open Access Journals (Sweden)

    Elba Rosa Luna Maldonado de Yankilevich

    1993-12-01

    Full Text Available Se describen los resultados de una investigación desarollada sobre una muestra de 1.115 preescolares (5 años de jardines de infantes de la Ciudad de Córdoba (Argentina, destinada a establecer la prevalencia y distribución de la caries dental conforme a su nivel económicosocial. El estudio reveló que, respecto a 1973, la prevalencia de caries disminuyó el 55,0%, en tanto que la proporción de niños con dientes sanos fue mayor en el 26,7%. La frecuencia y severidad de la caries aumentó a medida que descendía la ubicación social del niño. En el nivel económicosocial más alto (NES I = burguesías empresarial y gerencial, los índices de caries fueron significativamente menores que en el nivel económicosocial más bajo (NES III = proletariado típico, proletariado no típico y subproletariado: ceo-d de 0,8 y 2,7 y ceo-s de 0,9 y 4,9, respectivamente. En el NES III, los principales componentes del ceo-d fueron dientes cariados y con extracción indicada, mientras que en el NES I fueron los dientes obturados. La proporción de niños sin experiencia de caries fue del 63,1% en el NES I y del 11,5% en el NES III. Inversamente, el índice de salud bucal resultó más alto en el NES I (8,8 que en el NES III (5,1. El gasto demandado por niño para el tratamiento restaurativo es aproximadamente dos veces y media más alto en el NES III que en el NES I. Considerando toda la muestra, el gasto en el NES III resultaría más de diez veces superior al del NES I. Se concluye que la programación de la atención odontológica privilegiando a los niños del NES III, que son los de mayor riesgo de enfermar, puede contribuir a contrarrestar los desniveles en el estado de salud bucal.

  6. Distribución de la caries dental en niños preescolares en una región urbana, Argentina, 1992

    Directory of Open Access Journals (Sweden)

    Yankilevich Elba Rosa Luna Maldonado de

    1993-01-01

    Full Text Available Se describen los resultados de una investigación desarollada sobre una muestra de 1.115 preescolares (5 años de jardines de infantes de la Ciudad de Córdoba (Argentina, destinada a establecer la prevalencia y distribución de la caries dental conforme a su nivel económicosocial. El estudio reveló que, respecto a 1973, la prevalencia de caries disminuyó el 55,0%, en tanto que la proporción de niños con dientes sanos fue mayor en el 26,7%. La frecuencia y severidad de la caries aumentó a medida que descendía la ubicación social del niño. En el nivel económicosocial más alto (NES I = burguesías empresarial y gerencial, los índices de caries fueron significativamente menores que en el nivel económicosocial más bajo (NES III = proletariado típico, proletariado no típico y subproletariado: ceo-d de 0,8 y 2,7 y ceo-s de 0,9 y 4,9, respectivamente. En el NES III, los principales componentes del ceo-d fueron dientes cariados y con extracción indicada, mientras que en el NES I fueron los dientes obturados. La proporción de niños sin experiencia de caries fue del 63,1% en el NES I y del 11,5% en el NES III. Inversamente, el índice de salud bucal resultó más alto en el NES I (8,8 que en el NES III (5,1. El gasto demandado por niño para el tratamiento restaurativo es aproximadamente dos veces y media más alto en el NES III que en el NES I. Considerando toda la muestra, el gasto en el NES III resultaría más de diez veces superior al del NES I. Se concluye que la programación de la atención odontológica privilegiando a los niños del NES III, que son los de mayor riesgo de enfermar, puede contribuir a contrarrestar los desniveles en el estado de salud bucal.

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

    Directory of Open Access Journals (Sweden)

    Zakiyah Zakiyah

    2012-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Duski Ibrahim

    2015-10-01

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

  9. Determinación de la edad de muerte a través del análisis de la altura total de la corona dental en muestras del Holoceno temprano del sudeste de la región pampeana

    Directory of Open Access Journals (Sweden)

    Barrientos, Gustavo

    2001-01-01

    Full Text Available La exploración de nuevas vías metodológicas y técnicas que permitan inferir con mayor precisión la estructura etárea de muestras arqueológicas y que, al mismo tiempo, incorporen parámetros de marcada especificidad poblacional (i.e. desgaste dental, constituye actualmente un problema relevante en bioarqueología. El objetivo de este trabajo es presentar la metodología utilizada para la determinación de la edad de muerte basada en el análisis de la variación intramuestral en la altura total de la corona dental (ATC. Para ello se analizó una muestra de 18 individuos del sitio Arroyo Seco 2 (Pcia. de Buenos Aires; ca. 8000 a 6000 años AP. La ATC, definida como la sumatoria de las alturas linguales y bucales de la corona de cada pieza dental, se midió en la totalidad de los dientes permanentes presentes (400 piezas dentales. Con los datos correspondientes al M1, M1 y M2 de los individuos subadultos, se generaron nueve curvas suavizadas por ponderación exponencial negativa con intersección en x= 0 a los 55, 60 y 65 años para al M1 y M1 y 61, 66 y 71 años para M2. Las edades de los individuos adultos se calcularon mediante el uso de cada uno de los modelos de curvas generados, promediándose los resultados obtenidos para cada diente y obteniéndose la media ponderada de las mismas. Finalmente, se compararon las distribuciones de edades resultantes con las derivadas del análisis de la sínfisis púbica y de la superficie auricular del ilion. Se concluye que el conjunto de los resultados obtenidos permite considerar a la media ponderada como la mejor estimación de la edad de muerte de los individuos que integran la muestra, debido a que ésta presentó la mejor correlación (R= 0,84 con las edades derivadas del uso de otros indicadores.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zhang Jing

    2010-02-01

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

  14. AlGaN nanocolumns and AlGaN/GaN/AlGaN nanostructures grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, J.; Sanchez-Garcia, M.A.; Ulloa, J.M.; Calleja, E. [Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Sanchez-Paramo, J.; Calleja, J.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Jahn, U.; Trampert, A.; Ploog, K.H. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2002-12-01

    This work reports on the characterization of hexagonal, single crystal AlGaN nanocolumns with diameters in the range of 30 to 100 nm grown by molecular beam epitaxy on Si(111) substrates. The change of the flux ratio between the Al and the total III-element controls the alloy composition. The Al composition trend versus the Al flux is consistent both with the E{sub 2} phonon energy values measured by inelastic light scattering and the luminescence emission peaks position. High quality low dimensional AlGaN/GaN/AlGaN heterostructures with five GaN quantum discs, 2 and 4 nm thick, embedded into the AlGaN columns, were designed in order to study the quantum confinement effects. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  15. Simplificação do índice CPO dos 18 aos 25 anos DMF Index simplification from 18 to 25 years

    Directory of Open Access Journals (Sweden)

    Luiz O. C. Guimarães

    1990-10-01

    Full Text Available O índice CPO pode ser estimado pelo dobro do valor obtido pelo exame de dois hemiarcos (superior direito e inferior esquerdo, e pelo quádruplo do valor observado em seis dentes (primeiro molar e incisivo central superiores direitos, primeiro pré-molar superior esquerdo, segundo molar e incisivo lateral inferiores esquerdos e segundo pré-molar inferior direito. As estimativas foram feitas por métodos da estatística descritiva, em termos de média, composição percentual e coeficiente de prevalência de cárie, tendo-se levantado dados em 100 indivíduos de 18 a 25 anos.The DMF index can be estimated at double the value observed in the exam of two hemiarchs (Upper Right and Lower Left, or at four times the value obtained from six teeth (First Molar and Central Incisor Upper Right, first bicuspid upper left, second molar and lateral incisor lower left and second bicuspid lower right. The estimates were made by the use of methods of descriptive statistics, averages, percentages and the coefficient of the prevalence of caries, in a sample of 100 people, aged from 18 to 25 years.

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

    Directory of Open Access Journals (Sweden)

    Muhammad Ardy Zaini

    2015-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    YU Huashun; CHEN Hongmei; MA Rendian; MIN Guanghui

    2006-01-01

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

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

    International Nuclear Information System (INIS)

    Wang Xiaoming

    2005-01-01

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

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

    International Nuclear Information System (INIS)

    Shahmiri, M.; Shahin, K.

    2001-01-01

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

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

    Science.gov (United States)

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

    2017-12-22

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

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Ahmad Fawaid

    2015-12-01

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

  3. La hiperdontia en región de molares Hyperdontia in molar region

    Directory of Open Access Journals (Sweden)

    George Táccio de Miranda Candeiro

    2011-12-01

    Full Text Available La hiperdontia constituye una de las anomalías más estudiadas de la dentición humana. Esa alteración representa la aparición de uno o más dientes en cantidades mayores de lo normal, que puede ocurrir en la mandíbula o maxila y de manera unilateral o bilateral. La etiología de los dientes supernumerarios puede ser explicada principalmente por hiperactividad de la lámina dentaria en la fase inicial. Es importante la detección precoz de dientes supernumerarios porque se ha visto una serie de complicaciones como los diastemas, que pueden causar en la cavidad bucal: retardo de la erupción o dientes impactados, posicionamiento inadecuado de dientes permanentes, desajuste oclusal y el desarrollo de quistes y tumores odontógenos. Así el diagnóstico es normalmente realizado a partir de un examen radiográfico convencional, principalmente la radiografía panorámica. Este trabajo tuvo como objetivo relatar 4 casos clínicos de pacientes con presencia de molares supernumerarios, que fueron atendidos en el Servicio de Radiología de la Escuela de Odontología de la Universidad Federal de Ceará.Hyperdontia is one of the more studied anomalies of human dentition. This alteration represents the appearance of one or more teeth in a number greater of normal, occurring in mandible or in maxilla and could be unilateral or bilateral. The etiology of supernumerary teeth may be explained mainly due to the hyperactivity of dental plate in its initial phase; its early detection is important because of there have been a series of complications that may to cause diastemata, eruption retard or impacted teeth, inappropriate positioning of permanent teeth, occlusal misalignment and the development of odontogenic cysts or tumors. Thus, the diagnosis is normally made from a conventional radiographic examination, mainly the panoramic X-ray. The objective of present paper is the present four clinical cases of patients presenting with supernumerary molars, seen in

  4. Reabsorción radicular inflamatoria en sujetos con tratamiento ortodóntico. Cartagena (Colombia

    Directory of Open Access Journals (Sweden)

    Farith González Martínez

    2012-01-01

    Full Text Available Objetivo: Determinar la ocurrencia de Reabsorción Radicular Inflamatoria en sujetos sometidos a movimiento dental con cuatro técnicas de ortodoncia. Materiales y métodos: Estudio de cohorte con seguimiento a un año, evaluando la reabsorción radicular inflamatoria con cuatro técnicas de ortodoncia, a partir de la escala de Levander and Malmgren. Las mediciones se realizaron en 176 dientes, usando tres radiografías periapicales por participante cada tres meses. Los datos fueron analizados a través de proporciones de incidencia. El Riesgo Relativo se utilizó para la asociación entre la presencia de reabsorción y la técnica de ortodoncia, con intervalos de confianza del 95 %. Para la significancia estadística se aplicaron los test de Kruskal Wallis, Mc-Nemar y Fischer. Se realizó un análisis multivariable por regresión logística. Resultados: La incidencia de Reabsorción Radicular fue del 68,2 %, presentándose a los nueve y doce meses. Se observaron cambios radiculares con grado 1 en 8,5 % de los dientes y grado 2 con 2,8 %, siendo laterales los de mayor proporción (6,3%. En los dientes sometidos a la técnica de Arco de canto se encontró un riesgo 3,3 veces mayor en comparación con las técnicas pre-ajustadas. Conclusiones: Existe Reabsorción Radicular en los dientes sometidos a movimiento dental durante el tratamiento de ortodoncia, sin embargo, estos cambios se consideran leves y dependen de la biomecánica utilizada en cada técnica.

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

    International Nuclear Information System (INIS)

    Li, Shuo; Bhushan, Bharat

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

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

    Directory of Open Access Journals (Sweden)

    Reza Pahlevi

    2016-07-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  9. Al2O3 adherence on CoCrAl alloys

    International Nuclear Information System (INIS)

    Kingsley, L.M.

    1980-04-01

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

  10. Características generales de la fluorosis dental

    Directory of Open Access Journals (Sweden)

    Josefa Calderón Betancourt

    2014-11-01

    Full Text Available Se realizó una revisión bibliográfica, utilizando los recursos disponibles desde la red infomed, con el objetivo de describir las características generales de la fluorosis dental. Esta es la hipomineralización del esmalte dental y tiene tres formas de presentación: leve, moderada y severa. Su cuadro clínico esta dado principalmente por manchas blanquecinas que cubre una mínima superficie del diente, hasta manchas de color café oscuro y su complicación más temida es la fractura que causa una agresiva y acentuada pérdida de la estructura dentaria. Es causada por el acumulo excesivo de flúor en el diente. Su prevención está encaminada a la administración de flúor sistémico en las diferentes edades y entre las recomendaciones para evitarla se encuentra: usar en lo posible agua con el nivel adecuado de flúor, utilizar pastas de dientes con los contenidos óptimos de flúor, excepto en las zonas con aguas fluoradas y no aplicar las lacas fluoradas a estos niños

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

    Directory of Open Access Journals (Sweden)

    Adlini Ilma Ghaisany Sjah

    2014-02-01

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

  12. 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 ...

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

    International Nuclear Information System (INIS)

    Duan, Jinsong

    2007-01-01

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

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

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    Dr. Muhammad Riaz al Azhari

    2017-01-01

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

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

    Science.gov (United States)

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

    2018-03-01

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

  16. ANÁLISIS DESCRIPTIVO DE LA RESPUESTA DEL COMPLEJO PULPO-DENTINAL DE ÓRGANOS DENTALES DE UNA POBLACIÓN PREHISPÁNICA CAZADORA-RECOLECTORA

    Directory of Open Access Journals (Sweden)

    María Clemencia Vargas Vargas

    2012-01-01

    Full Text Available Antecedentes: El diente es de gran importancia cuando se trata de caracterizar individuos, poblaciones vivas o desaparecidas. Este componente es el que más resiste a la descomposición, debido a que al terminar su calcificación, el diente se conforma definitivamente y por tal razón no sufre ningún cambio. A excepción del desgaste mecánico o atrición y la acumulación de dentina secundaria. Objetivo: Deducir los posibles factores etiológicos que ocasionaron grandes desgastes dentales y condujeron a una rápida respuesta del complejo pulpo dentinal, en los individuos pertenecientes a una población prehispánica de cazadores-recolectores, del precerámico temprano y tardío cuya dieta era basada en alimentos fibrogénicos y abrasivos. Materiales y Métodos: Estudio descriptivo transversal donde se tomaron 15 piezas dentales, pertenecientes a dos poblaciones cazadoras-recolectoras: Precerámico temprano (Chequa y Precerámico tardío (Aguazuque.  A estos dos grupos se tomaron las muestras para realizar un análisis clínico, radiográfico y microscópico. Resultados: Disminución evidente en el tamaño de la corona clínica dental, se observaron diferentes grados de desgaste dental con exposición dentinaria delimitado por esmalte en su circunferencia. La dentina expuesta por el desgaste dental presenta un color amarillo, las superficies oclusales e incisales se presentan lisas. Ninguna de las piezas dentarias presentó signos clínicos de caries. Respecto al examen radiográfico, los datos obtenidos confirmaron los hallazgos clínicos. Conclusiones: El desgaste dental es la característica clínica que más se presentó, posiblemente asociado al consumo de alimentos fibrosos y a la fuerza imprimida en la acción masticatoria, además es agravado por partículas abrasivas que se adherían a los alimentos, durante la maceración con elementos líticos. Las estructuras dentales más afectadas por el desgaste dental corresponden al esmalte y

  17. Terceros retenidos según su ubicación

    OpenAIRE

    Barreto, Milena Natalia

    2017-01-01

    Los terceros molares empiezan su formación alrededor de los 8 años de edadterminando su amelogénesis a los 18 o 20 años y completando su ápico-formación entre los 20 a 23 años. En la retención interósea (el diente esta rodeado por tejido óseo) o extra ósea (el diente esta rodeado por mucosa gingival) de los terceros molares, la causa principal es por la falta de espacio dentro de la boca. Los signos y síntomas que se presentan son: encías inflamadas y dolorosas disminución apertura bucal, dol...

  18. EFECTO DEL PASTOREO SOBRE LA PRODUCCIÓN Y PERSISTENCIA DE UN CULTIVO DE ESPARCETA

    OpenAIRE

    DELGADO, I.; MUÑOZ, F.; DEMDOUM, S.

    2013-01-01

    Se comparó la producción de forraje, composición química y persistencia de una pradera de esparceta, aprovechada a diente por ganado ovino en dos estados fenológicos, inicio (IF) y plena floración (PF), con la producción para heno, en regadío, en Zaragoza, durante 2010 y 2011. Se hicieron seis aprovechamientos en 2010 y tres en 2011, hasta que la densidad de plantas se redujo de 149 a 17 plantas m-2. Destacó por producción de materia seca (MS) el aprovechamiento a diente en PF con 14 846 kg M...

  19. Tratamiento implanto protético de la agenesia del segundo premolar superior: Reporte de un caso clínico

    OpenAIRE

    Tomaghelli, Emanuel Ricardo; Perdomo Sturniolo, Ivana Lorena

    2017-01-01

    La agenesia dental es una de las anomalías craneofaciales más comunes en el desarrollo humano. Paciente de género femenino de 22 años de edad que a la inspección ocular se observa la persistencia del diente temporario de la pieza Nº 65, realizando un examen radiográfico en búsqueda del diente permanente retenido o en ubicación ectópica se observa la “agenesia” del mismo. Como plan de tratamiento se optó por la exodoncia atraumática de la pieza temporaria y la colocación inmediata de un impla...

  20. Tamaños radiculares y coronales de molares temporales en una muestra de niños españoles.

    OpenAIRE

    Caleya Zambrano, Antonia María

    2011-01-01

    La reabsorción de los dientes temporales ha sido poco estudiada a pesar de que es un proceso fisiológico de gran relevancia en el ser humano. El estudio de la rizolisis podría servir para determinar el estado de maduración del niño, y por tanto tener una aplicación útil en la práctica clínica y forense de la odontología. Por ello en este trabajo de investigación, nos hemos centrado en el estudio de la rizolisis de los dientes temporales. [ABSTRACT] The aim of this work is to study the rhii...

  1. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

  3. Corrección de mordida cruzada posterior vestibular en dentición primaria. Reporte de dos casos clínico

    Directory of Open Access Journals (Sweden)

    Jerusalén E. Mata T.

    2016-07-01

    Full Text Available La mordida cruzada posterior vestibular cruzada bucal o mordida en tijera ocurre cuando las cúspides linguales de los molares superiores ocluyen vestibularmente a las fosas centrales de los molares inferiores o cuando las caras palatinas de los dientes superiores están en contacto con las caras vestibulares de los dientes inferiores. Pueden ser funcionales, causadas por inclinación de los molares inferiores hacia lingual o por asimetrías mandibulares. El tratamiento temprano es recomendado para normalizar las relaciones transversales y promover un correcto desarrollo de la oclusión. Se presentan dos casos de mordida cruzada posterior vestibular unilateral en dentición primaria y mixta temprana. Caso 1: paciente masculino de 5 años de edad, presentó lesiones extensas de caries, normoclusión, mordida cruzada posterior vestibular unilateral derecha y fue tratado mediante aparato fijo tipo Bi-Helix con bandas cementadas a los segundos molares primarios. Caso 2: paciente masculino de 5 años de edad, presentó lesiones extensas de caries, normoclusión y mordida cruzada posterior vestibular unilateral Izquierda. Fueron colocadas pistas directas de resina. En ambos casos se logró una relación trasversal satisfactoria, corrigiendo la mordida cruzada vestibular. Conclusión: La mordida cruzada posterior vestibular puede presentarse debido a desviación mandibular por interferencias oclusales y a inclinaciones inapropiadas de los molares primarios. Cuando esta es la etiología, el tratamiento es exitoso al utilizar pistas directas de resina, eliminación de contactos prematuros y expansor inferior tipo Bi-Helix.

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

    Directory of Open Access Journals (Sweden)

    Abdul Sattar

    2011-06-01

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

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

    OpenAIRE

    Molina, Luis

    2005-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  7. Anomalías dentomaxilofaciales en dientes permanentes y su relación con traumas en la primera infancia Dental-maxillary-facial anomalies in permanent teeth and their relation to traumas in early childhood

    Directory of Open Access Journals (Sweden)

    Arlene Liset Corrales León

    2009-03-01

    Full Text Available Se realizó un estudio descriptivo, longitudinal y retrospectivo que incluyó niños de 7 a 14 años de edad, pertenecientes al área de salud de la "Clínica Estomatológica Docente Guama" del municipio Pinar del Río, en el período comprendido entre febrero del 2003 a marzo de 2005, con el objetivo de determinar la presencia de anomalías dentomaxilofaciales en dentición permanente y su relación con traumas en la primera infancia. El universo de estudio estuvo constituido por 250 niños, y de ellos, se seleccionó una muestra de 60 niños y se les confeccionó una planilla recolectora de datos para la investigación. Los resultados obtenidos fueron procesados estadísticamente mediante el sistema automatizado STATISTIC y la prueba de CHI CUADRADO, en su aplicación de bondad de ajuste, y el paquete SPSS, para la prueba de comparación de proporciones. En todos los casos se prefija un nivel de significación de 0,05. Entre los resultados globales más significativos encontramos que fueron los traumas ocurridos en las edades de 5-6 años los que más anomalías dentomaxilofaciales causaron en la dentición permanente. Resultó el sexo masculino el más afectado por estas alteraciones, fueron los traumas recibidos directamente sobre los dientes, los mayores causantes de anomalías en la dentición permanente. Resultaron las hipoplasias del esmalte, como otras anomalías no ortodóncicas las más frecuentes; se comprobó que el sexo femenino tuvo mayor implicación psicosocial por estas alteraciones y se divulgaron a estomatólogos, padres y maestros orientaciones sobre la relación entre los traumas en la primera infancia y las anomalías dentomaxilofaciales en la dentición permanente.A descriptive, longitudinal and retrospective research was carried out including children from 7 to 14 years old belonging to the health area of "Guama" Dental University Clinic in Pinar del Rio Municipality, from February 2003 to March 2005 aimed at determining

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

    Directory of Open Access Journals (Sweden)

    Eliyahu, Ayala

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-08-19

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  11. Sintering Behavior of CNT Reinforced Al6061 and Al2124 Nanocomposites

    Directory of Open Access Journals (Sweden)

    Nouari Saheb

    2014-01-01

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

  12. Tendencias contemporáneas de las bases fisiopatológicas del bruxismo

    Directory of Open Access Journals (Sweden)

    Damila Nápoles García

    2014-08-01

    Full Text Available El bruxismo es un hábito parafuncional diurno o nocturno, caracterizado por rechinar y/o apretar los dientes. Hoy día se le concede un origen multicausal y entre los factores más relevantes figuran los psíquicos o psicosomáticos. Teniendo en cuenta las múltiples consecuencias clínicas que ocasiona, en términos de dolor, deterioro dental y osteomioarticular, se le considera uno de los trastornos orofaciales más complejos, de difícil tratamiento y pronóstico reservado. De acuerdo con la complejidad de este tema y de los conocimientos actuales al respecto, se realizó la presente investigación para describir las tendencias actuales en la fisiopatología de esta enfermedad

  13. GlasKon `99 - 7th Innovation Forum for Glass, Architecture, and Technology from January 18 to 23, 1999; GlasKon `99: 7. Innovations-Forum Glas, Architektur, Technik - Kongress und Ausstellung in Verbindung mit der Bau `99; GlasKon `99 - 7th Innovation Forum for Glass, Architecture, and Technology from January 18 to 23, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Krewinkel, H.W.; Seger, P.E.; Achenbach, J. [comps.

    1999-10-01

    Thanks to its basic properties, i.e. transparency, weather resistance, and easy recyclability, glass is very well suited as a ``solar radiation-trapping`` building material. This congress and exhibition report presents, amongst other things, a solar glass of variable light and energy transmission, possibilities of passivsolar energy recovery in non-transparent facades, glazing for intelligent daylight utilisation, and innovative facades with photovoltaics. Four contributions have been abstracted individually for the Energy Database. [Deutsch] Der Baustoff Glas mit seinen grundlegenden Eigenschaften - Transparenz, Wetterbestaendigkeit sowie problemlose Recyclebarkeit dient auch als `` solare Strahlenfalle``. Im Folgenden werden ein Sonnenschutzglas mit veraenderbarer Licht-und Energietransmission, Moeglichkeiten der passiven solaren Energiegewinnung im nicht-transparentern Fassadenbereich, Verglasungen fuer die intelligente Tageslichtnutzung sowie innovative Fassaden mit Photovoltaik vorgestellt. Fuer die Datenbank Energy wurden vier Beitraege einzeln aufgenommen.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Luthfi Hadi Aminuddin

    2013-11-01

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

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

    International Nuclear Information System (INIS)

    Fale, Sandeep; Likhite, Ajay; Bhatt, Jatin

    2014-01-01

    Highlights: • Formation of in-situ phases nucleated on AlN particles strengthens the matrix. • Formation of in-situ phases increases with AlN content in nanocomposites. • Stronger in-situ phases results in increased hardness and modulus of elasticity. - Abstract: Nanocrystalline Aluminium nitride (AlN) powder is dispersed in different weight ratio in Aluminum matrix to fabricate metal matrix nanocomposite (MMNC) using ex situ melt metallurgy process. The synthesized Al–AlN nanocomposites are studied for phase analysis using high resolution scanning electron microscopy (FEG-SEM) and for hardness behavior using microindentation and nanoindentation tests. Quantitative analysis of the oxide phases is calculated from thermodynamic data and mass balance equation using elemental data obtained from energy dispersive spectroscopy (EDS) results. Role of oxide phases in association with AlN particles is investigated to understand the mechanical behavior of composites using nanoindentation tester. Load–displacement profile obtained from nanoindentation test reveals distribution of oxide phases along with AlN particle and their effect on indent penetration

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    International Nuclear Information System (INIS)

    Paillard, P.

    1977-01-01

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

  19. 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.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    D.R. Zaynuddinov

    2017-03-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  4. Resultados de un sistema para la vigilancia de caries de la infancia temprana

    Directory of Open Access Journals (Sweden)

    Eduardo BERNABÉ ORTIZ

    2006-10-01

    Full Text Available Objetivo: Describir los resultados de un sistema, implementado con los estudiantes de la Facultad de Estomatología Roberto Beltrán Neira, para la vigilancia de caries de la infancia temprana (CIT en niños entre 6 y 36 meses de edad de comunidades urbano-marginales de Sol Naciente de Carabayllo. Materiales y métodos: Sesenta y dos de los 97 niños que aceptaron participar en la evaluación inicial durante el semestre 2004-I, fueron reexaminados a los 12 (semestre 2005-I y 18 meses (semestre 2005-II empleando los criterios diagnósticos recomendados por la Organización Mundial de la Salud. Los resultados del sistema de vigilancia son descritos en términos de prevalencia e incidencia de CIT así como de experiencia de caries dental (índices ceod y ceos. Resultados: La prevalencia inicial de CIT fue de 24,2%, 8,2% y 2,6% por unidad persona, diente y superficie respectivamente, con un ceod de 1,10 + 2,51 dientes y un ceos de 1,50 + 3,71 superficies. Después de 18 meses, la incidencia de CIT fue de 4,3%, 2,6% y 1,3% por unidad persona, diente y superficie, encontrándose un incremento significativo de 0,32 dientes en el ceod (p<0,001 y de 0,74 superficies en el ceos (p=0,001. Conclusiones: Los resultados indican un inicio temprano (prevalencia moderada y desarrollo lento (baja incidencia de la CIT en niños de 6 a 36 meses de las comunidades seleccionadas. Esta información es útil para planificar futuras intervenciones con un enfoque preventivo o recuperativo en este grupo de edad.

  5. Diagnóstico y manejo de la anquilosis dentoalveolar

    Directory of Open Access Journals (Sweden)

    María Alejandra Cardozo

    2015-07-01

    Full Text Available La Anquilosis Dentoalveolar es una anomalía dental, en la cual se presenta perdida de continuidad del ligamento periodontal, lo que lleva a la unión del hueso alveolar con el cemento o la dentina. Esto impide el proceso eruptivo normal y el crecimiento vertical óseo del diente anquilosado, mientras que los dientes adyacentes siguen su proceso de erupción y crecimiento alveolar normal. Esta situación genera que el diente alterado esté por debajo del plano oclusal, dando la impresión de estar sumergido. La anquilosis es casi exclusiva de la dentición primaria y su prevalencia varía entre 1,3 y 8,9%, presentándose con mayor frecuencia en los primeros molares primarios inferiores. Su etiología exacta aun se desconoce, pero existen diferentes teorías acerca del origen de esta alteración, una de estas es el factor genético y la perturbación del metabolismo local del ligamento periodontal. La presencia de anquilosis puede favorecer el desarrollo de diversas alteraciones en la dentición, como perdida de perímetro del arco, inclinación de dientes adyacentes, perdida de espacio y alteraciones de la masticación entre otras. Por esto es de gran importancia el diagnóstico clínico y radiográfico para la realización de un tratamiento oportuno para prevenir y minimizar el desequilibrio oclusal. Las alternativas terapéuticas para la anquilosis dentoalveolar son controvertidas, y la decisión de tratamiento básicamente esta orientada con base en los hallazgos clínicos y radiográficos, en las implicaciones clínicas y en la severidad de la infraoclusión.

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

    Directory of Open Access Journals (Sweden)

    A.M Ismatulloh

    2012-12-01

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

  7. Onlinespieler abseits des Mainstreams

    Directory of Open Access Journals (Sweden)

    Harald Baumgartlinger

    2012-12-01

    Full Text Available MMO(RPGs „Massively Multiplayer Online (Role-Playing Games“ nehmen einen Sonderstatus unter den Onlinespielen ein, welcher durch den wachsenden wirtschaftlichen Erfolg, insbesondere durch den „breakthrough hit“ (Duchenaut et al. 2006: 407 World of Warcraft (WoW, auch an Bedeutung für die Medien- und Kommunikationswissenschaft gewinnt (vgl. Inderst 2009: 15; vgl. Seifert/Jöckel 2008: 297. Der Primus des Genres, WoW, repräsentiert gemeinsam mit einigen nahezu identen Titeln insgesamt 85 Prozent der gespielten MMOGs (vgl. Williams et al. 2008: 999. Daher befasst sich auch die Mehrheit der vorliegenden Studien mit eben diesen Spielen. Neue Formen von MMO(Gs können jedoch zu ebenso neuartigen Spielerfahrungen führen und damit unterschiedliche Nutzungsmotive befriedigen (vgl. Seifert/Jöckel 2008: 309 und folglich zu einem gänzlich anderen Spielerleben führen. Während im Mainstream die kooperativen Spielerbeziehungen überwiegen, dominiert in Darkfall Online der soziale Wettbewerb. Der von Williams et al. 2008 verwendete Fragebogen diente als Rohling für die Kreation eines für die speziellen Anforderungen adaptierten Erhebungstools zur Erforschung der Spielertypologie und der Motive der Darkfall-Online-SpielerInnen. Die in der Onlinebefragung (N = 506 gesammelten Daten belegen, dass sich sowohl die Spielerdemographie, als auch die Motive der Spieler von den Mainstream MMOs unterscheiden. Zudem konnten realweltliche Eigenschaften der Spieler als signifikante Einflussfaktoren für die Spielzuwendung identifiziert werden.

  8. Dental caries and treatment needs among indigenous people of the Potiguara Indian reservation in Brazil Caries dental y necesidades de tratamiento en los indígenas de la reserva india Potiguara de Brasil

    Directory of Open Access Journals (Sweden)

    Fábio Correia Sampaio

    2010-04-01

    Full Text Available OBJETIVE: The aim of this study was to assess the caries prevalence and treatment needs of Brazilian indigenous residents on an Indian reservation. METHODS: This cross-sectional study comprised 1 461 individuals of ages 18-36 months and 5, 12, 15-19, 35-44, and 65-74 years living in the Potiguara Indian villages of Brazil. Decayed, missing, or filled permanent teeth (DMFT and deciduous teeth (dmft were determined by calibrated examiners using the methodology recommended by the World Health Organization. Treatment needs were assessed with the guidelines of the 2003 Brazilian Oral Health Survey. RESULTS: Means ± standard deviations (SD for dmft of 18- to 36-month-old and 5-year-old children were 2.5 ± 3.7 and 5.8 ± 4.3, respectively. For the age groups 12, 15-19, 35-44, and 65-74 years, mean ± SD values of DMFT were 3.6 ± 3.1, 7.1 ± 4.9, 16.4 ± 7.5, and 22.8 ± 8.6. The mean ± SD number of deciduous teeth requiring treatment varied from 2.4 ± 3.5 to 5.0 ± 4.0 in the 18- to 36-month and 5-year-old age groups, respectively. Among adolescents and adults, it was observed that on average at least three permanent teeth required dental treatment such as fillings, crowns, endodontic treatment, and extractions. CONCLUSIONS: High prevalence of caries and many teeth needing treatment were observed in all age groups of the Potiguara Indians.OBJETIVO: El objetivo de este estudio fue evaluar la prevalencia de caries y las necesidades de tratamiento en los residentes indígenas brasileños de una reserva india. MÉTODOS: En este estudio transversal se incluyó a 1 461 personas de 18 a 36 meses de edad, y de 5, 12, 15-19, 35-44, y 65-74 años, que vivían en aldeas indias Potiguara de Brasil. Se determinaron los dientes permanentes cariados, perdidos y obturados (CPO y los dientes deciduos mediante examinadores calibrados, con ayuda del método recomendado por la Organización Mundial de la Salud. Las necesidades de tratamiento se evaluaron con las

  9. Integration of liquid-cooled solar collectors into building walls; Gebaeudeintegration von Sonnenkollektoren mit Fluessigkeitskuehlung

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, S.; Rockendorf, G.; Bartelsen, B. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany)

    1998-02-01

    Three different methods are presented how to integrate active solar thermal components into building facades. The solar thermal absorber acts as overheating protection and the heat produced can be utilized further. The lower annual yield in comparison to roof-mounted installations is counterbalanced by a more uniform solar gain and an improved wall insulation. The new concept of elastomer-metal-absorbers can be realized in different configurations and material combinations and offers attractive options for collector installation. The methods discussed hold the promise of significant cost reductions. (orig.) [Deutsch] Es werden drei Methoden vorgestellt, aktive solarthermische Komponenten mit Fluessigkeit als Waermetraeger in die Gebaeudehuelle zu integrieren. Dabei dient der solarthermische Absorber als Ueberhitzungsschutz und die abgefuehrte Waerme kann einer Nutzung zugefuehrt werden. Der geringere jaehrliche Waermeertrag im Vergleich zur Dachmontage wird durch ein gleichmaesssiges Ertragsprofil und eine verbesserte Waermedaemmung weitgehend ausgeglichen. Das neu entwickelte Elastomer-Metall-Absorber-Konzept (EMA-Konzept) ist in unterschiedliche Konfigurationen und Materialkombinationen umsetzbar und eroeffnet attraktive Moeglichkeiten der Kollektorinstallation. Die diskutierten Methoden lassen eine deutliche Kostenersparnis erwarten. (orig.)

  10. "Doing pupil" nach Schulschluss – Videografie an einer Kinderuniversität

    Directory of Open Access Journals (Sweden)

    Alexandra König

    2015-03-01

    Full Text Available Auf der Basis einer Videografie an einer Kinderuniversität wird in dem vorliegenden Beitrag die Frage verfolgt, wie an einem außerschulischen Lernort generationale Ordnung hergestellt wird und welche Gestalt diese annimmt. Als heuristischer Rahmen dient das Modell der "Sozialisation als generationales Ordnen" (BÜHLER-NIEDERBERGER 2011; BÜHLER-NIEDERBERGER & TÜRKYILMAZ 2014. Die Analyse der ersten Sitzungen von zwei kontrastiven Kursen an der Kinder- und Jugenduniversität zeigt erstens, wie Kinder struktursensitiv Regeln in dem unbekannten Kontext erspüren, erarbeiten und modifizieren, wie sie KomplizInnen in der Herstellung generationaler Ordnung sind. Zweitens wird die Dominanz der schulischen Ordnung und des SchülerInnenstatus für Kindheit deutlich. Die Kinder stellen "Schule" her – paradoxerweise auch in einem außerschulischen Kontext. Drittens wird im kontrastiven Vergleich der untersuchten Kurse eine Varianz dieser Ordnungen – in Bezug auf die Form des Wissens und Adressierung der Kinder – herausgearbeitet, die allerdings die Dominanz der schulischen Ordnung nicht bricht. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs150263

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Agus Setiawan

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    M. S. Kaiser

    2014-12-01

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

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

    Science.gov (United States)

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

    2006-03-28

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

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

    Directory of Open Access Journals (Sweden)

    Liming Liu

    2014-02-01

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

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

    Science.gov (United States)

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

    2010-08-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Md. Toufiq Iqbal

    2014-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Z.S. Ilyasova

    2016-12-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-09-01

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

  5. Electronic Structures and Bonding Properties of Ti2AlC and Ti3AlC2

    Institute of Scientific and Technical Information of China (English)

    MIN Xinmin; REN Yi

    2007-01-01

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

  6. Diversos usos instrumentales del aparato masticatorio en restos humanos de la Patagonia Argentina

    Directory of Open Access Journals (Sweden)

    Kozameh, Livia Febes

    2005-01-01

    Full Text Available Desgastes dentarios atípicos y disarmónicos, asociados a patologías sugirieron la posibilidad que los mismos se hubieran producido por una actividad masticatoria excesiva y no alimentaria. La variedad de rastros registrados sugiere el uso de la boca con fines instrumentales, como recurso posiblemente constante. Los casos seleccionados son seis y sus rasgos predominantes se describen sucintamente. 1 Muestra dentaria de canoeros fueguinos. Fracturas cuspídeas pulimentadas únicamente en denticiones femeninas.2Resto de cazador canoero del Beagle. Notables desgastes dentarios con distintas angulaciones a modo de zigzag. Raíces en función oclusal con procesos alveolares concomitantes. 3Resto de cazador pedestre de Tierra del Fuego. Disminución del tamaño coronal de los dientes anteriores y primeros premolares, con pérdida completa de su morfología. Los bordes incisales exhiben tres planos de desgaste con diferentes direcciones. 4 y 5Cazadores de Santa Cruz. En uno de ellos los desgastes coronales son convexos en todos sus dientes. Patologías alveolares. En el otro ejemplar el desgaste tornó cilíndricas las coronas de las piezas anteriores. 6Resto femenino de Chubut. Pérdida prematura de los cuatro dientes anteriores con compromiso óseo y canino transpuesto.

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

    OpenAIRE

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

    2007-01-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Rong Fu Chen

    2011-05-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2015-10-01

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

  13. Hipomineralización incisivo Y molar: diagnóstico diferencial

    OpenAIRE

    Souza, Juliana Feltrin [UNESP; Jeremias, Fabiano [UNESP; Silva, Cristiane Maria da Costa [UNESP; Zuanon, Angela Cristina Cilense [UNESP; Santos-Pinto, Lourdes Aparecida Martins dos [UNESP; Cordeiro, Rita De Cássia Loiola [UNESP

    2011-01-01

    Hypomineralized first molar often in combination with hypomineralized incisors (MIH - molar incisor hypomineralization) is a common finding in everyday practice. In this condition, hypomineralized dental enamel is fragile and soft, and it can break easily leading to an exposed dentin, and causing dental sensitivity and progression of caries lesions. The prevalence of MIH range from 3.6 to 25% in North of Europe that consider this condition a public health problem. No conclusive information wa...

  14. 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...

  15. 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  17. Vitalidade pulpar em dentes portadores de brackets ortodônticos: apresentação de uma técnica = Pulp vitality test on teeth having orthodontics brackets: technique presentation

    Directory of Open Access Journals (Sweden)

    Barletta, Fernando Branco

    2007-01-01

    Full Text Available O presente trabalho teve como objetivo avaliar a confiabilidade do teste de vitalidade pulpar com o gás refrigerante tetrafluoretano (CS 68 em dentes portadores de brackets ortodônticos. Foram selecionados 37 pacientes de clínica privada, com faixa etária entre 12 e 60 anos de idade. O teste de vitalidade pulpar foi realizado na face palatina ou lingual, na região de terço médio dos dentes, abaixo do cíngulo, nos grupos dentários dos incisivos, caninos e pré-molares superiores e inferiores, totalizando 402 dentes. Quando a resposta de sensibilidade pulpar era negativa ao teste, o mesmo era repetido; confirmando-se o resultado como negativo, realizavase uma tomada radiográfica pela técnica periapical do dente em questão. Os resultados evidenciaram 4 elementos dentários com resposta negativa ao teste de vitalidade pulpar, sendo 3 pré-molares e um incisivo central. A resposta dos demais foi positiva ao teste. Diante dos resultados, verificou-se que a aplicação do teste de vitalidade pulpar pela face palatina em pacientes portadores de brackets ortodônticos constitui-se em uma alternativa segura e confiável

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Soravia, Bruna

    2004-12-01

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

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

  2. 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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    OpenAIRE

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

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-08

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

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

    Directory of Open Access Journals (Sweden)

    Asep Nahrul Musadad

    2015-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Shahla Moradi

    2017-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-15

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    Novel Al-based composites (Al-C-Cu-Al 2 O 3 ) obtained by mechanical milling (MM), were characterized by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). Analyses of composites were carried out in both, the as-milled and the as-sintered conditions. C nanoparticles were found in the as-milled condition and Al 2 O 3 nanofibers were found in as-sintered products, as determined by EELS. C and Cu react with Al to crystallize in Al 3 C 4 and Al 2 Cu structures, respectively

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-30

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

  12. Enfoque quirúrgico de canino incluido en el paladar: Reporte de un caso y revisión dela literatura

    Directory of Open Access Journals (Sweden)

    Adel Martínez Martínez

    2013-10-01

    Full Text Available ResumenLa inclusión dental hace referencia a la anomalía en la cual el diente pierde la fuerza de erupción y se encuentra sumergido en el maxilar con o sin patología asociada. El diente que más frecuentemente queda retenido después de los terceros molares mandibulares es el canino maxilar con una prevalencia que oscila entre el 1- 2.2 % dependiendo de la población evaluada. El diagnóstico de un canino incluido en el maxilar se realiza mediante evaluación clínica que incluye la inspección y palpación además del examen radiográfico periapical y panorámico. Varias opciones de tratamiento se pueden aconsejar al paciente desde el tratamiento interceptivo, la remoción quirúrgica del canino retenido, la exposición quirúrgica y tracción ortodóntica, el trasplante hasta el tratamiento no activo y observación, valorando las características individuales tanto del paciente como de la situación e inclinación del diente. A continuación se realiza una revisión bibliográfica seguida del reporte de caso clínico de un canino retenido en paladar en un paciente masculino de 27 años de edad donde esta indicada la extracción quirúrgica. (Duazary 2009 I; 56-61AbstractDental inclusion is when the tooth has lost the forcing eruption and is submerge in the maxilla with or any pathology. Maxillary canine are the most frecuently impacted teeth after the third molar with a prevalence ranging from 1 to 2•2% depending on the population examined. The diagnosis of an impacted maxillary canine is based through clinical evaluation that includes inspection, palpation and radiographic examination that involve taking periapical and orthopantomograph radiographs. Patient counseling on the various treatment options, from the interceptive treatment, the surgical remove of the ectopic canine, the surgical exposure and orthodontic alignment, the transplantation until the no active treatment and observation. We carried out a bibliographical revision

  13. "Arrancale los dientes al trópico": ambiente,enfermedad y el programa sanitario de Estados Unidos en Panamá, 1904-1914

    Directory of Open Access Journals (Sweden)

    Paul Sutter

    2000-01-01

    Full Text Available Apoyado en fuentes escritas durante y después de la construcción del Canal de Panamá (1904- 1914, este artículo examina la forma en que los estadunidenses conceptualizaron los trópicos de Panamá y el modo en que dicha conceptualización orientó su política, en especial la sanitaria, durante el periodo de construcción del canal. Debido a que las enfermedades tropicales, en especial la malaria y la fiebre amarilla, ocupaban un lugar central en el modo de concebir los trópicos por parte de los estadunidenses, el objetivo de este trabajo es mostrar que los problemas de enfermedades en Panamá eran el resultado de complejas interacciones ambientales y sociales, y no una mera característica natural de los trópicos.

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  15. Quiste odontógeno: Presentación de caso

    Directory of Open Access Journals (Sweden)

    Gladys Pérez López

    2003-12-01

    Full Text Available Se presenta un paciente de 18 años de edad, remitido al Servicio de Otorrinolaringología del Hospital Clinicoquirúrgico "Comandante Manuel Fajardo", con el cuadro clínico de sinusitis recurrente y opacidad homogénea de seno maxilar izquierdo . La radiografia convencional de senos perinasales es considerada un medio diagnóstico muy importante al nivel de la atención primaria de salud, aunque también se considera necesario el ortopantograma para el diagnóstico diferencial (dientes supernumerarios, quistes dentígenos, molares retenidos. La técnica de Caldwell-Luc mejora la visibilidad y accesibilidad de las lesions, contribuye al diagnóstico, al alivio del paciente y está exenta de complicaciones.A case of 18-years old male patient with recurrent maxillary sinusitis and radiographic study with opacity in left maxillay sinus was reported. He was admitted at the Otorhinolaringology Department of "Comandante Manuel Fajardo" university clinical and surgical hospital. Conventional radiographic examination of perinasal sinus is considered a very important tool in primary health care; but also orthopantogram is required to exclude diverse diagnosis (supernumerary teeth, dentigenous cyst, and embedded tooth. The Caldwell-Luc approach improves visibility of and accesibility to lesions, contributes to make diagnosis and relieves the patient's condition without further complications. The most relevant quotations found in research works about the topic were selected.

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

    Science.gov (United States)

    2017-10-01

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

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

    Science.gov (United States)

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

    2005-02-01

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

  18. 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 ...

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

    Directory of Open Access Journals (Sweden)

    Yusuf Hanafi

    2015-09-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

  1. Estudio embriológico de Iguana iguana (Linnaeus, 1758 bajo condiciones de incubación controladas

    Directory of Open Access Journals (Sweden)

    Edith Liliana Guzmán Lotero

    2000-07-01

    Full Text Available Se realiza un estudio de Iguana iguana para establecer los estadios embrionarios que caracterizan la especie, bajo condiciones de incubaci6n artificial controladas de 32.5°C y humedad relativa promedio de 90% ± 2, colectándose y fijándose 5 huevos diarios a partir de la postura y durante 67 días. El peso promedio de los huevos fue de 15.4001 g, largo 3.84 mm, ancho 2.7 mm, notándose que estos son independientes del tiempo transcurrido de incubación. El peso de los embriones no presenció diferencias significativas durante los primeros 6 estadios (periodo embrionario, a partir del estadio 7 (periódo fetal existen valores que van de 1.5834 g a 7.2323 g. 14 dimensiones fueron evaluadas en cada embrión, encontrándose que todas están directamente relacionadas con el tiempo de incubación. Se establecieron 12 estadios embrionarios para Iguana iguana teniendo en cuenta una tipificación rnorfométrica y morfológica, lepidosis, organización de órganos, proceso mandibular, grade de diferenciación de bulbos en extremidades y presencia de lengua, entre otros. Los embriones de Iguana iguana continúan su desarrollo postovipuestos con la presencia de esbozo cardíaco y hepático. Al final del estadio 8 la porción distal de la lengua se observa dividida en dos. Solo en el estadio 12 se evidencian los dientes y e! ovirruptor o diente embrionario. Los hemipenes en embriones machos, se mantienen externos durante todo el proceso embrionario.

  2. ¿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.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  5. 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

  6. Automation of room temperature control and heating cost distribution and components for further development; Automatisierung der Raumtemperaturregelung und Heizkostenverteilung sowie Komponenten ihrer Weiterentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Riedel, M.; Bentscheff, S. [Dr. Riedel Automatisierungstechnik GmbH, Berlin (Germany)

    1997-12-31

    The paper studies how much heat energy can be saved in buildings connected to the district heat grid by using an innovative automation system. This system not only permits to cut down energy consumption; it reduces service and administrative effort as well and enhances comfort. It helps to control the temperature of individual rooms, measure heat energy consumption in detail, and allocate heating costs. In 15 000 residential units this system is already in use. (MSK) [Deutsch] Die Untersuchung zielt auf das Einsparpotential an Heizwaerme in fernwaermeversorgten Gebaeuden bei Einsatz eines innovativen Automatisierungssystems. Neben der Reduktion des Energieverbrauchs ermoeglicht das System eine Reduktion des Service- und Verwaltungsaufwands und eine Erhoehung des Komforts. Es dient sowohl der Einzelraum-Temperaturregelung und der detaillierten Messung der Heizwaermebverbraeuche als auch der Heizkostenverteilung. Derzeit wird das System bereits in 15000 Wohungen eingesetzt.

  7. The use of hybrid dry cooling towers/condensors; Einsatz von hybriden Trockenkuehltuermen/Verfluessigern

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, W. [Jaeggi/Guentner AG, Feldmeilen (Switzerland). Niederlassung Ostschweiz

    1998-03-01

    The hybride dry cooling tower/condenser has a closed circuit and an air side heat transfer surface which can be wetted. It is used for recooling of a liquide fluid (Water/Glycole) or for condensation of refrigerant by outdoor air and by evaporation of water from a secondary loop. This cooling tower concept has higher first costs, but considerably lower annual costs compared with similar cooling systems. The economy can be shown by a calculated example. (orig.) [Deutsch] Der hybride Trockenkuehlturm/Verfluessiger hat einen geschlossenen Kreislauf und eine wasserbenetzbare, luftseitige Waermeuebertragungsflaeche. Er dient der Rueckkuehlung eines fluessigen Mediums (Wasser/Glykol) oder der Verfluessigung von Kaeltemitteln mittels Umgebungsluft und durch Verdunstung von Wasser aus einem Sekundaerkreislauf. Dieser Kuehlturm hat hoehere Investitionskosten, aber wesentlich tiefere Jahreskosten als aehnliche Kuehlsysteme. Die Wirtschaftlichkeit wird anhand eines gerechneten Beispiels nachgewiesen. (orig.)

  8. Zadie Smith: un homenaje

    Directory of Open Access Journals (Sweden)

    Rivera de la Cruz, Marta

    2009-06-01

    Full Text Available Considerada por la prestigiosa revista Granta uno de los nombres propios de las letras anglosajonas, Zadie Smith irrumpió en la escena literaria con Dientes blancos cuando contaba con poco más de veinte años. Su extraordinario talento unido a su extrema juventud sorprendieron a la crítica, pero también al público y a los medios de comunicación, que no tardaron en hacer de ella un nuevo icono de la literatura moderna. Zadie Smith ha pasado los últimos años escribiendo y huyendo a la vez de la feria de vanidades de la fama, que amenazaba con oscurecer sus dotes de narradora. Es una escritora total, cuya tercera novela, Sobre la belleza, la ha consagrado de forma definitiva.

  9. Herausforderungen beim Aufbau und bei der Pflege einer Bilddatenbank – ein Anwendungsbeispiel aus dem Digitalen Forschungsarchiv Byzanz (DiFAB

    Directory of Open Access Journals (Sweden)

    Nina Rannharter

    2017-09-01

    Full Text Available Mit Metadaten versehene, digital archivierte Bilder sind aufgrund ihrer hohen Komplexität eine ständige Herausforderung für den Aufbau von Metadatenstrukturen und für das Beibehalten von adäquaten Metadatenstandards in Bilddatenbanken. Besonders bei Bildern über eine materielle Kultur zeichnet sich diese Komplexität in den diversen Ebenen ab. Zur Verdeutlichung dieser Problematik dient ein einzelnes Monument mit seiner fotographischen Dokumentation als geisteswissenschaftliches Anwendungsbeispiel aus dem Digitalen Forschungsarchiv Byzanz (DiFAB der Universität Wien. Unter der grundsätzlichen Berücksichtigung der künftigen Anforderungen und der einfachen Navigation von Metadaten beinhaltet dieser Beitrag u. a. die Herausforderungen mit den diversen analogen und digitalen Formen der Dokumentation, der historischen Geographie, der kulturspezifischen Terminologie sowie mit der kunsthistorischen Bedeutung einer exakten und unscharfen Datierung für Forschungsarchive.

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

    Science.gov (United States)

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

    2006-12-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. Hot Corrosion Behavior of Stainless Steel with Al-Si/Al-Si-Cr Coating

    Science.gov (United States)

    Fu, Guangyan; Wu, Yongzhao; Liu, Qun; Li, Rongguang; Su, Yong

    2017-03-01

    The 1Cr18Ni9Ti stainless steel with Al-Si/Al-Si-Cr coatings is prepared by slurry process and vacuum diffusion, and the hot corrosion behavior of the stainless steel with/without the coatings is studied under the condition of Na2SO4 film at 950 °C in air. Results show that the corrosion kinetics of stainless steel, the stainless steel with Al-Si coating and the stainless steel with Al-Si-Cr coating follow parabolic laws in several segments. After 24 h corrosion, the sequence of the mass gain for the three alloys is the stainless steel with Al-Si-Cr coating coating coating. The corrosion products of the three alloys are layered. Thereinto, the corrosion products of stainless steel without coating are divided into two layers, where the outside layer contains a composite of Fe2O3 and FeO, and the inner layer is Cr2O3. The corrosion products of the stainless steel with Al-Si coating are also divided into two layers, of which the outside layer mainly consists of Cr2O3, and the inner layer is mainly SiO2. The corrosion film of the stainless steel with Al-Si-Cr coating is thin and dense, which combines well with substrate. Thereinto, the outside layer is mainly Cr2O3, and the inside layer is Al2O3. In the matrix of all of the three alloys, there exist small amount of sulfides. Continuous and protective films of Cr2O3, SiO2 and Al2O3 form on the surface of the stainless steel with Al-Si and Al-Si-Cr coatings, which prevent further oxidation or sulfide corrosion of matrix metals, and this is the main reason for the much smaller mass gain of the two alloys than that of the stainless steel without any coatings in the 24 h hot corrosion process.

  13. Gate length scaling effect on high-electron mobility transistors devices using AlGaN/GaN and AlInN/AlN/GaN heterostructures.

    Science.gov (United States)

    Liao, S Y; Lu, C C; Chang, T; Huang, C F; Cheng, C H; Chang, L B

    2014-08-01

    Compared to AlGaN/GaN HEMT with 0.15 μm T-gate length, the AlInN/AlN/GaN one exhibits much higher current density and transconductance of 1558 mA/mm at Vd = 2 V and 330 mS/mm, respectively. The high extrinsic ft and fmax of 82 GHz and 70 GHz are extracted from AlInN/AlN/GaN HEMT. Besides, we find that the transconductance roll-off is significant in AlGaN/GaN, but largely improved in AlInN/AlN/GaN HEMT, suggesting that the high carrier density and lattice-matched epitaxial heterostructure is important to reach both large RF output power and high operation frequency, especially for an aggressively gate length scaling.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-11-01

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

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Marikar, P.

    1979-06-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2018-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-29

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

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

    Directory of Open Access Journals (Sweden)

    Naoki Yamamoto

    2013-12-01

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

  3. PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni2AlTiCOMPOUND

    Institute of Scientific and Technical Information of China (English)

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

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  5. Prevalência de defeitos de esmalte em indivíduos portadores de fissuras labiopalatinas da Paraíba, Brasil

    Directory of Open Access Journals (Sweden)

    Rosa Helena Wanderley Lacerda

    2012-03-01

    Full Text Available Os defeitos de esmalte estão entre as alterações que acometem os indivíduos portadores de fissuras labiopalatinas. O propósito do presente estudo foi descrever a prevalência de defeitos de esmalte em indivíduos portadores de fissuras, bem como a sua distribuição quanto ao tipo de fissura e lado fissurado, nos pacientes que procuraram o serviço de referência em ortodontia no atendimento de fissurados da Paraíba, Brasil. Para tanto, este estudo caracterizou-se por ser do tipo transversal e observacional, adotando como estratégia de coleta de dados o exame clínico em 76 indivíduos portadores de fissuras pós e transforame incisivo unilateral ou bilateral, de ambos os sexos, com média de idade de 13,3 anos. O exame foi realizado nos dentes incisivos e caninos superiores, por dois examinadores previamente treinados (kappa= 0,89. Os pacientes incluídos foram todos que estavam em atendimento no período de janeiro a junho de 2011 em que as faces vestibulares dos dentes a serem examinados permitissem a avaliação clínica. Foram excluídos os que apresentavam outras deformidades associadas e que não tivessem sido submetidos às cirurgias primárias. Os dados foram submetidos à estatística descritiva e ao teste estatístico qui-quadrado, sendo significativo ao nível de 5 %. Houve predominância do gênero masculino (57,9 % e da fissura transforame incisiva unilateral esquerda (40,8 %. Em relação ao defeito de esmalte, o dente mais acometido foi o incisivo central, a maioria dos examinados apresentou opacidade difusa (14,9 %, seguida pela presença de opacidade demarcada (13,15 % e opacidade mais hipoplasia (10,9 % e houve diferença estatística significativa (p< 0,00001 entre o lado fissurado e o contralateral. Os resultados mostram elevada frequência de defeitos de esmalte nos pacientes estudados, particularmente nos casos bilaterais e nos dentes adjacentes à fissura.

  6. Efeito da perda prematura de molares decíduos na sobressaliência

    Directory of Open Access Journals (Sweden)

    Yérica M García

    2011-01-01

    Full Text Available A perda precoce de molares decíduos predispõe as maloclusões, entre estas o apinhamento dentário, impactação de dentes permanentes e alteração da relação molar e canino. O objetivo do estudo foi determinar o efeito das perdas precoces dos molares decíduos na relação horizontal incisiva. O estudo é do tipo documentado, retrospetivo e observacional. Foram avaliados os registros ortodônticos (histórias clínicas, fotografias e radiografias de 209 pacientes na faixa etária de 4 a 15 anos de idade. A relação incisiva horizontal foi considerada normal para os pacientes do GRUPO 1, com contato entre a face incisal dos incisivos inferiores e a face palatina dos incisivos superiores. No GRUPO 2, a relação incisiva horizontal foi considerada aumentada, com distância positiva entre eles e no GRUPO 3, a relação incisiva horizontal foi considerada negativa quando as faces incisais dos incisivos superiores e inferiores se encontravam a topo ou em mordida cruzada. Os dados foram analisados através do coeficiente Pearson (p ≤ 0,001. Na análise dos dados coletados, o total de quarenta e cinco pacientes (22% apresentaram perdas prematuras. A prevalência destas perdas não apresentou diferença significativa entre sexos e foi maior no grupo de faixa etária de 7 a 9 anos de idade. Dos pacientes com perda prematura seis (13,3% foram clasificados no GRUPO 1; doze (26,7% no GRUPO 2 e vinte e sete (60% no GRUPO 3. A relação entre o número de molares perdidos e a presença de mordida cruzada anterior foi encontrada, e a média de molares perdidos (4,7 foi maior no GRUPO 3. Os resultados mostraram que as perdas precoces dos molares decíduos apresentam uma relação estatisticamente significante com a mordida cruzada anterior, sugerindo que a falta de suporte oclusal pode favorecer o desenvolvimento protrusivo da mandibula.

  7. 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.

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

    OpenAIRE

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2008-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Anggraini Binti Ramli

    2016-12-01

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

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

    OpenAIRE

    Embabi, Nabil S.

    1981-01-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

  13. Bukti Kebenaran Al-quran

    OpenAIRE

    Aliyah, Sri

    2015-01-01

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

  14. Chemical strategies for modifications of the solar cell process, from wafering to emitter diffusion; Chemische Ansaetze zur Neuordnung des Solarzellenprozesses ausgehend vom Wafering bis hin zur Emitterdiffusion

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Kuno

    2009-11-06

    The paper describes the classic standard industrial solar cell based on monocrystalline silicon and describes new methods of fabrication. The first is an alternative wafering concept using laser microjet cutting instead of multiwire cutting. This method originally uses pure, deionized water; it was modified so that the liquid jet will not only be a liquid light conductor but also a transport medium for etching fluids supporting thermal abrasion of silicon by the laser jet. Two etching fluids were tested experimentally; it was found that water-free fluids based on perfluorinated solvents with very slight additions of gaseous chlorine are superior to all other options. In the second section, the wet chemical process steps between wafering and emitter diffusion (i.e. the first high-temperature step) was to be modified. Alternatives to 2-propanol were to be found in the experimental part. Purification after texturing was to be rationalized in order to reduce the process cost, either by using less chemical substances or by achieving shorter process times. 1-pentanol and p-toluolsulfonic acid were identified as two potential alternatives to 2-propanol as texture additives. Finally, it could be shown that wire-cut substrates processed with the new texturing agents have higher mechanical stabilities than substrates used with the classic texturing agent 2-propanol. [German] Im ersten Kapitel wird die klassische Standard-Industrie-Solarzelle auf der Basis monokristallinen Siliziums vorgestellt. Der bisherige Herstellungsprozess der Standard-Industrie-Solarzelle, der in wesentlichen Teilen darauf abzielt, diese Verluste zu minimieren, dient als Referenz fuer die Entwicklung neuer Fertigungsverfahren, wie sie in dieser Arbeit vorgestellt werden. Den ersten thematischen Schwerpunkt bildet die Entwicklung eines alternativen Wafering-Konzeptes zum Multi-Drahtsaegen. Die Basis des neuen, hier vorgestellten Wafering-Prozesses bildet das Laser-Micro-Jet-Verfahren. Dieses System

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Bo Yu

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  18. Prevalencia de lesiones incipientes de caries dental en niños escolares Prevalence of incipient lesions of dental caries in school children

    Directory of Open Access Journals (Sweden)

    Nayda Nasco Hidalgo

    2008-06-01

    Full Text Available OBJETIVOS: determinar la prevalencia de lesiones incipientes de caries dental en los niños de 6-11 años de la escuela primaria "José A Echeverría," municipio Plaza de la Revolución en el período de enero a diciembre del 2006, identificar en el grupo estudiado, la frecuencia de niños según número de lesiones incipientes y la frecuencia de lesiones incipientes por ubicación del diente en la arcada y por superficie dentaria. MÉTODOS: se realizó un estudio observacional descriptivo de corte transversal, el universo estuvo integrado por todos los niños que estuvieran en esas edades y que cumplieran con los criterios de inclusión, para un total de 236, los cuales fueron examinados al aire libre y con luz natural, utilizando el método visual- táctil suave. Los dientes se limpiaron con algodón y se secaron con peras de aire para detectar la presencia de lesiones incipientes de caries, las cuales fueron señalizadas en un modelo de dentigrama, en el lugar correspondiente a la superficie afectada. RESULTADOS: se halló que el 22,5 % de los escolares examinados presentaba estas lesiones, de ellos el 60,1 % correspondió al sexo femenino; el 19,5 % del total de niños presentó una lesión y sólo el 3% tenia dos lesiones incipientes de caries dental; el 79,2 % de las mismas se encontraron en los dientes posteriores, fueron las superficies lisas las más afectadas con un 45,3 %. CONCLUSIONES: Alrededor de la cuarta parte de los niños estudiados presentaron lesiones incipientes de caries, siendo el sexo femenino el más afectado. Del total de niños que poseían lesiones incipientes, la mayor cifra correspondió a los que presentaban una lesión. Los dientes posteriores fueron los más afectados por lesiones incipientes. Las superficies lisas mostraron más lesiones incipientes que las oclusales y proximalesOBJECTIVES: to determine the prevalence of incipient lesions of dental caries in children aged 6-11 of "José A Echeverría" Primary

  19. 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

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

    Science.gov (United States)

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

    2017-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-01

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

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

    KAUST Repository

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

    2010-01-01

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

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

    KAUST Repository

    Wang, Junsheng

    2010-10-27

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

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Bhishma Pandit

    2016-06-01

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

  8. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    International Nuclear Information System (INIS)

    Wolf, W.; Bolfarini, C.; Kiminami, C.S.; Botta, W.J.

    2016-01-01

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al 71 Co 13 Fe 8 Cr 8 , Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al 71 Co 13 Fe 8 Cr 8 alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al 71 Co 13 Fe 8 Cr 8 . The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al 5 Co 2 and Al 13 Co 4 and are quasicrystalline approximants. Although the Al 5 Co 2 phase has already been reported in the Al 71 Co 13 Fe 8 Cr 8 alloy, the presence of the monoclinic Al 13 Co 4 is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al 13 Co 4 phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al 71 Co 13 Fe 8 Cr 8 alloy, the compositions Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were chosen to be within the region of formation of the quaternary extension of the Al 13 Co 4 phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system, around the compositions studied, is composed of quaternary extensions of Al-Co intermetallic phases, which present solubility of Fe and Cr at Co atomic sites. - Highlights: •The Al rich region of the Al

  9. Comparison of ALS functionality and plant growth in ALS-inhibitor susceptible and resistant Myosoton aquaticum L.

    Science.gov (United States)

    Liu, Weitang; Bai, Shuang; Jia, Sisi; Guo, Wenlei; Zhang, Lele; Li, Wei; Wang, Jinxin

    2017-10-01

    Herbicide target-site resistance mutations may cause pleiotropic effects on plant ecology and physiology. The effect of several known (Pro197Ser, Pro197Leu Pro197Ala, and Pro197Glu) target-site resistance mutations of the ALS gene on both ALS functionality and plant vegetative growth of weed Myosoton aquaticum L. (water chickweed) have been investigated here. The enzyme kinetics of ALS from four purified water chickweed populations that each homozygous for the specific target-site resistance-endowing mutations were characterized and the effect of these mutations on plant growth was assessed via relative growth rate (RGR) analysis. Plants homozygous for Pro197Ser and Pro197Leu exhibited higher extractable ALS activity than susceptible (S) plants, while all ALS mutations with no negative change in ALS kinetics. The Pro197Leu mutation increased ALS sensitivity to isoleucine and valine, and Pro197Glu mutation slightly increased ALS sensitivity to isoleucine. RGR results indicated that none of these ALS resistance mutations impose negative pleiotropic effects on relative growth rate. However, resistant (R) seeds had a lowed germination rate than S seeds. This study provides baseline information on ALS functionality and plant growth characteristics associated with ALS inhibitor resistance-endowing mutations in water chickweed. Copyright © 2017. Published by Elsevier Inc.

  10. AL FIKR AL BALAGHI FI AL MA’ĂNI ‘INDA AS SAKĂKI FI KITABIHI MIFTAHUL ULUM DIRĂSAH BALAGHIYYAH

    Directory of Open Access Journals (Sweden)

    Talqis Nurdianto

    2018-02-01

    Full Text Available Miftāhul ‘Ulūm, written by al-Sakākī, especially the third part, was the beginning of a new phase in the development of Arabic rhetoric. Al-Sakākī divided the rhetoric into three fields of study, which are  (1 Ma’ānī, (2 Bayān, (3 Badī’. However, his style is influenced by philosophers, theologians and their verbal lexicon, which are difficult to take, especially for the ordinary recipient. Al-Sakākī described that his book containing several types of literature, namely, ‘ilm ṣarf in complete version and its conclusion, derivation science, and the grammatical study in the completeness of Ma’ānī and Bayān. The meaning of Makna is the study of completeness and conclusion. Therefore, books and prose, and poem require al-‘Arūḍ and al-Qawāfī include Ṣarf, Grammar, Ma’ānī, Bayān, limitation, reasoning, al’Arūḍ, and al-Qawāfī. He argued that the fields of study were influential in delivering knowledge to the student in order to reach the goal of the author towards his book.This research was an analytical descriptive study of al-Sakākī rhetoric that focused on the normative aspect represented by rhetorical rule and aesthetic aspects. Those aspects were shown by the feeling. Al-Sakākī rhetoric thought is a method based on mental division and has conducted in the construction of many factors, which the most important of them are philosophy and logic. Keywords: thought, rhetoric, meanings, sakkaki, study

  11. A study on wear resistance and microcrack of the Ti3Al/TiAl + TiC ceramic layer deposited by laser cladding on Ti-6Al-4V alloy

    International Nuclear Information System (INIS)

    Li Jianing; Chen Chuanzhong; Squartini, Tiziano; He Qingshan

    2010-01-01

    Laser cladding of the Al + TiC alloy powder on Ti-6Al-4V alloy can form the Ti 3 Al/TiAl + TiC ceramic layer. In this study, TiC particle-dispersed Ti 3 Al/TiAl matrix ceramic layer on the Ti-6Al-4V alloy by laser cladding has been researched by means of X-ray diffraction, scanning electron microscope, electron probe micro-analyzer, energy dispersive spectrometer. The main difference from the earlier reports is that Ti 3 Al/TiAl has been chosen as the matrix of the composite coating. The wear resistance of the Al + 30 wt.% TiC and the Al + 40 wt.% TiC cladding layer was approximately 2 times greater than that of the Ti-6Al-4V substrate due to the reinforcement of the Ti 3 Al/TiAl + TiC hard phases. However, when the TiC mass percent was above 40 wt.%, the thermal stress value was greater than the materials yield strength limit in the ceramic layer, the microcrack was present and its wear resistance decreased.

  12. Study of the 27Al(n,2,)26Al reaction via accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Wallner, A.

    2000-06-01

    The excitation function for the 27 Al(n,2n) 26 Al reaction is expected to show a strongly non-linear behavior in the neutron-energy region around 14 MeV, the neutron energy in D-T plasmas; thus the production rate of 26 Al (t 1/2 =7.2*10 5 a) in D-T fusion environments can in principle be used to measure the temperature of such plasmas. Existing measurements, however, are strongly discordant. Therefore, a new accurate measurement of the 27 Al(n,2n) 26 Al cross sections in the near threshold region (E n =13.5-14.8 MeV) was performed with the goal to achieve relative cross sections with the highest accuracy possible. In addition, the measurements were also designed to provide good absolute cross-section values, as absolute cross sections are important for radioactive waste predictions. Samples of Al metal were irradiated with neutrons in the energy range near threshold (E th =13.55 MeV) at the Radiuminstitutes of both Vienna and St. Petersburg, and in Tokai-mura, Japan. In Tuebingen irradiations with neutrons of higher energies (17 and 19 MeV) were performed. The amount of 26 Al produced during the irradiations was measured via accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA). This work represents the first 26 Al measurements for this new facility. With this system, a background as low as 3*10 -15 for 26 Al/ 27 Al isotope ratios was obtained, corresponding to a (n,2n) cross section of 0.04 mb. Utilizing AMS, cross sections with much higher precision and considerably closer to the threshold than in previous investigations could be measured. The prerequisite for its application as a temperature monitor, namely a very well known shape of the excitation function was met. A quantitative prediction of the sensitivity of this method for monitoring the temperature in a D-T fusion plasma was therefore possible. For thermal plasmas temperature changes in the order of 5 to 15 % should be detectable. An even higher sensitivity was found

  13. Magnetostrictive properties of FeAl/polyester and FeAl/silicone composites

    Energy Technology Data Exchange (ETDEWEB)

    Riesgo, G. [Dpto. de Ciencias y Técnicas de la Navegación, Universidad de Oviedo, Campus universitario de Gijón, 33203 Gijón (Spain); Carrizo, J. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Elbaile, L., E-mail: elbaile@uniovi.es [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Crespo, R.D. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Sepúlveda, R. [Dpto. de Ingeniería Mecánica y de los Materiales, Universidad de Sevilla, Isla Cartuja, 41092 Sevilla (Spain); García, J.A. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2017-01-15

    Highlights: • Nanocrystalline powders of FeAl have been obtained from the Fe{sub 81}Al{sub 19} ribbon produced by melt spinning. • The method allows the obtainment of a FeAl solid solution from the starting process. • The microstructure and magnetic properties of the powders were investigated. • Composites with a magnetostriction of 45 ppm have been obtained. - Abstract: Ribbons of composition Fe{sub 81}Al{sub 19} obtained by the melt spinning method have been used to yield powder by mechanical milling. Using this method, a rapid nanocrystallization and a FeAl solid solution phase was obtained from the start of the process. The microstructural and magnetic properties as well as the XRD patterns of the powders were studied in function of the milling time. Grain refinement and an increase of the coercive field were the main transformations resulting from increasing the milling time. Two sets of magnetostrictive composites were produced from the 100 h-milled powder. In one of them polyester was used as matrix and in the other one silicone. In the case of the silicone composites cured in a magnetic field of 140 mT in the longitudinal direction a saturation magnetostriction as high as 45 ppm was obtained.

  14. Thermodynamic calculation of Al-Gd and Al-Gd-Mg phase equilibria checked by key experiments

    International Nuclear Information System (INIS)

    Groebner, J.; Kevorkov, D.; Schmid-Fetzer, R.

    2001-01-01

    The binary Al-Gd and the ternary Al-Gd-Mg systems were calculated using the Calphad method. It is demonstrated that previous interpretation of ternary liquidus temperatures below 700 C must be related to other phase equilibria. The actual ternary liquidus temperatures are much higher, up to some 600 C above the previous interpretation in literature. They are widely governed by the high-melting compounds Al 2 Gd and Al 3 Gd with liquidus surfaces stretching far into the ternary system. A small number of key experiments in this work confirmed the calculated liquidus temperature and the phase relations. The available experimental data in literature fit excellently with the calculation in the binary Al-Gd system. In the ternary Al-Gd-Mg system, which is shown in several sections of the phase diagram, a good agreement can be observed too, considering the necessary reinterpretation of the liquidus temperatures suggested by Rokhlin et al. Ternary solubilities were not found experimentally. The ternary compound Al 4 GdMg (τ) forms in a ternary peritectic reaction at 761 C. (orig.)

  15. Forged HITEMAL: Al-based MMCs strengthened with nanometric thick Al{sub 2}O{sub 3} skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Balog, Martin, E-mail: ummsbama@savba.sk [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Krizik, Peter; Nosko, Martin; Hajovska, Zuzana [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Victoria Castro Riglos, Maria [Centro Atómico Bariloche, Av. Bustillo 9.500, 8400 Bariloche, Río Negro (Argentina); Rajner, Walter [New Materials Development GmbH, Römerstrasse 28, 83410 Laufen, Leobendorf (Germany); Liu, De-Shin [National Chung Cheng University, 168 University Rd., Min-Hsiung, 62102 Chia-Yi, Taiwan (China); Simancik, Frantisek [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia)

    2014-09-08

    Bulk Al–Al{sub 2}O{sub 3} metal matrix composites (MMCs) named HITEMAL (high temperature aluminum) were fabricated in situ by forging compaction of five different types of gas-atomized commercial purity Al powders with a mean particle size in the range of 1–9 µm. As-forged HITEMAL consisted of (sub)micrometric Al grains (matrix) decorated with nanometric thick amorphous Al{sub 2}O{sub 3} (a-Al{sub 2}O{sub 3}) skeleton. Low-angle grain boundaries (LAGBs) free of Al{sub 2}O{sub 3} were located in the Al grain interior. The Al grain size and the portion of LAGBs increased with the increase in the relative powder surface area. As-forged HITEMAL shows excellent thermal stability up to 400 °C for 24 h. Annealing at temperatures ≥450 °C led to crystallization and morphological transformation from a-Al{sub 2}O{sub 3} skeleton to nanometric γ-Al{sub 2}O{sub 3} particles. Owing to the pinning effect of Al{sub 2}O{sub 3} phase, no Al grain growth took place during annealing up to 500 °C. HITEMAL showed attractive mechanical properties especially when tested at 300 °C (yield strength up to 220 MPa, Young's modulus up to 58 GPa). Despite the presence of a nearly continuous a-Al{sub 2}O{sub 3} skeleton along adjacent Al grains, forged HITEMAL materials had reasonable room temperature elongation of 7–26%. HITEMAL's elongation decreased as the Al grain size decreased and with increased testing temperature. The loss in elongation (uniform and total) was attributed to the inhomogeneous flow, which occurred due to high densities of high angle grain boundaries (dislocation sinks) and small content of LAGBs. The strength of HITEMAL stemmed from grain boundary mediated strengthening mechanisms. The results showed a positive deviation from the Hall–Petch plot, which is typical behavior of ultrafine-grained metals. Transformation of a-Al{sub 2}O{sub 3} skeleton to γ-Al{sub 2}O{sub 3} particles led to deterioration of the HITEMAL strength and Young's modulus.

  16. Determination of Al concentration in Al doped ZnO using Auger spectra excited by Mo X-rays

    International Nuclear Information System (INIS)

    Toth, J.; Koever, L.; Cserny, I.; Varga, D.

    2006-01-01

    Complete text of publication follows. A good conductor with excellent transparency is of crucial importance for the window layer of CIGS solar cells. Al doped ZnO is a good candidate for this purpose, its conductivity depends on the concentration and chemical state of the Al dopant atoms. It was demonstrated that the non-conventional XPS using Mo X-rays for excitation is a very sensitive tool for the detection of Al, P, Si [1, 2, 3]. The present paper compares the experimental ratios for Zn/Al photoinduced peak intensity ratios obtained using both Al and Mo X-ray excitations. The Mo excited Zn/Al intensity ratios can be determined with higher selectivity and sensitivity than the Zn/Al intensity ratios excited by Al X-rays. The experiments were performed with a hemispherical deflector electron spectrometer [4]. The chemical state of the Al was identified to be close to that in Al 2 O 3 . The atomic concentrations were determined using a calibration curve based on ZnO/Al samples with known composition of Al. The energy dependent efficiency of the electron spectrometer was determined comparing REELS spectra of Cu specimen to standard spectra measured by K. Goto (Nagoya Institute of Technology, Japan). For evaluation of the Al atomic concentrations from the measured photoelectron intensities the photoionisation cross-sections of Band et al [5] and the IMFP data of S. Tanuma et al [6] and C.J. Powell and A. Jablonski [7] were used. (author)

  17. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    Science.gov (United States)

    Wang, Xiao; Wang, Wei; Wang, Jingli; Wu, Hao; Liu, Chang

    2017-03-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgGa δ doped AlGaN SLs. Mg acceptor activation energy was significantly reduced from 0.378 to 0.331 eV by using MgGa δ doping in SLs instead of traditional doping in alloys. This new process was confirmed to be able to realize high p-type doping in high Al-content AlGaN.

  18. Al-Shebab: An Al-Qaeda Affiliate Case Study (2Rev)

    Science.gov (United States)

    2017-10-01

    deputies responsible for finance , administration, and security. Coordination among regional groups is common.10 The deputy leader of al-Shebab, Mukhtar...Maaliya (Ministry of Finance ) controlled taxation. A complex court system also emerged. Multiple training camps were built that focused on hand-to-hand...Nathan Chandler, Counterterrorism and Counterinsurgency in Somalia: Assessing the Campaign Against Al Shabaab, Rand Corporation , 2016, accessed 6/5

  19. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    OpenAIRE

    Xiao Wang; Wei Wang; Jingli Wang; Hao Wu; Chang Liu

    2017-01-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgG...

  20. 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.

  1. NEK1 genetic variability in a Belgian cohort of ALS and ALS-FTD patients.

    Science.gov (United States)

    Nguyen, Hung Phuoc; Van Mossevelde, Sara; Dillen, Lubina; De Bleecker, Jan L; Moisse, Matthieu; Van Damme, Philip; Van Broeckhoven, Christine; van der Zee, Julie

    2018-01-01

    We evaluated the genetic impact of the amyotrophic lateral sclerosis (ALS) risk gene never in mitosis gene a-related kinase 1 (NEK1) in a Belgian cohort of 278 patients with ALS (n = 245) or ALS with frontotemporal dementia (ALS-FTD, n = 33) and 609 control individuals. We identified 2 ALS patients carrying a loss-of-function (LOF) mutation, p.Leu854Tyrfs*2 and p.Tyr871Valfs*17, that was absent in the control group. A third LOF variant p.Ser1036* was present in 2 sibs with familial ALS but also in an unrelated control person. Missense variants were common in both patients (3.6%) and controls (3.0%). The missense variant, p.Arg261His, which was previously associated with ALS risk, was detected with a minor allele frequency of 0.90% in patients compared to 0.33% in controls. Taken together, NEK1 LOF variants accounted for 1.1% of patients, although interpretation of pathogenicity and penetrance is complicated by the observation of occasional LOF variants in unaffected individuals (0.16%). Furthermore, enrichment of additional ALS gene mutations was observed in NEK1 carriers, suggestive of a "second hit" model were NEK1 variants may modify disease presentation of driving mutations. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Lichtdoorlatendheid van kasdekken onder verschillende omstsndigheden

    NARCIS (Netherlands)

    Bot, G.P.A.

    1984-01-01

    Aandacht voor lichtonderschepping; bewolkingsgraad; direkte straling; diffuse straling en gevolgen van veranderingen in kaskonstruktie of materiaaleigenschappen ten aanzien van de lichtdoorlatendheid. Bij vergelijking van de lichttransmissie van diverse kasdekken dient te worden uitgegaan van

  3. The effect of ammonia flow in the AlN spacer on the electrical properties of InAlN/AlN/GaN HEMT structures

    International Nuclear Information System (INIS)

    Gamarra, Piero; Lacam, Cedric; Magis, Michelle; Tordjman, Maurice; Di Forte Poisson, Marie-Antoinette

    2012-01-01

    During the past few years it has been reported that a thin AlN spacer of few nanometers needs to be inserted in InAlN/GaN high electron mobility transistors (HEMTs) to obtain high 2DEG carrier mobility. This work presents a systematic study of the effects of varying the ammonia flow in the AlN spacer of InAlN/AlN/GaN HEMTs grown by low pressure metalorganic vapour phase epitaxy (LP-MOVPE). The strain state, the surface roughness and the growth rate of AlN were found to be dependent on the V/III ratio. In addition the ammonia flow in the interlayer has a strong impact on the structural properties of the subsequent InAlN barrier layer and on the electrical properties of the structure. A sheet resistance as low as 327 Ω/□ with a sheet carrier density of 1.5 x 10 13 cm -2 has been obtained at room temperature. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. The effect of ammonia flow in the AlN spacer on the electrical properties of InAlN/AlN/GaN HEMT structures

    Energy Technology Data Exchange (ETDEWEB)

    Gamarra, Piero; Lacam, Cedric; Magis, Michelle; Tordjman, Maurice; Di Forte Poisson, Marie-Antoinette [III-V Lab., Marcussis (France)

    2012-01-15

    During the past few years it has been reported that a thin AlN spacer of few nanometers needs to be inserted in InAlN/GaN high electron mobility transistors (HEMTs) to obtain high 2DEG carrier mobility. This work presents a systematic study of the effects of varying the ammonia flow in the AlN spacer of InAlN/AlN/GaN HEMTs grown by low pressure metalorganic vapour phase epitaxy (LP-MOVPE). The strain state, the surface roughness and the growth rate of AlN were found to be dependent on the V/III ratio. In addition the ammonia flow in the interlayer has a strong impact on the structural properties of the subsequent InAlN barrier layer and on the electrical properties of the structure.istance as low as 327 {omega}/{open_square} with a sheet carrier density of 1.5 x 10{sup 13} cm{sup -2} has been obtained at room temperature. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, W., E-mail: witorw@gmail.com [Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Bolfarini, C., E-mail: cbolfa@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Kiminami, C.S., E-mail: kiminami@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Botta, W.J., E-mail: wjbotta@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil)

    2016-12-15

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}, Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}. The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al{sub 5}Co{sub 2} and Al{sub 13}Co{sub 4} and are quasicrystalline approximants. Although the Al{sub 5}Co{sub 2} phase has already been reported in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the presence of the monoclinic Al{sub 13}Co{sub 4} is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al{sub 13}Co{sub 4} phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the compositions Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were chosen to be within the region of formation of the quaternary extension of the Al{sub 13}Co{sub 4} phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system

  6. Corrosion analysis of AlMg2 and AlMgSi using electrochemical method

    International Nuclear Information System (INIS)

    Dian A; Maman Kartaman; Rosika K; Yanlinastuti

    2014-01-01

    Corrosion test of cladding materials and structures of research reactor fuel, AlMgSi and AlMg2 have been performed in demineralized water of pH 2 and 6.7 using an electrochemical method. Corrosion phenomenon is affected by several factor such as composition and condition of solution. The purpose of this activity is to investigate the corrosion phenomena through the determination of the parameters of corrosion and polarization curve. The materials used are AlMg2 and AlMgSi alloy in circular dish shape with an area of 1 Cm"2. Preparation of the test sample is performed through several stages polishing, cleaning and drying procedures followed ASTM G3. The electrochemical method is done by measuring the open circuit potential (OCP), polarization resistance and potentiodynamic in demineralized water of pH 2 and pH 6.7 at temperature of 25°C. The results of the OCP is the corrosion potential (Ecorr) of AlMg2 and AlMgSi each of -906.1 mV and -619.8 mV at pH 2 and -868.6 and -756.7 mV at pH 6.7 mV. The results of measurements by polarization resistance technique showed that the corrosion rate of AlMg2 and AlMgSi in safe category (<2 mpy) at pH 6.7 and at pH 2 corrosion rate increased significantly, but still in the lightweight category (<20 mpy). Potentiodynamic curves showed that the passivation at pH 6.7 is very low while the passivation at pH 2 occurs within a relatively short range potential and followed events corroded. (author)

  7. Catalytic effect of Al and AlN interlayer on the growth and properties of containing carbon films

    International Nuclear Information System (INIS)

    Zhou, Bing; Liu, Zhubo; Tang, Bin; Rogachev, A.V.

    2015-01-01

    Highlights: • DLC and CN x bilayers with Al (AlN) interlayer were fabricated by cathode arc technique. • Complete diffusion of Al and C atoms occurs at the interface of Al/DLC (CN x ) bilayer. • Al/CN x bilayer presents a higher content of Csp 3 /Csp 2 bonds. • The hardness of Al/DLC bilayer decreases but increases for the other bilayers. • Morphology of the bilayers was explained by growth mechanism of DLC and surface state of substrate. - Abstract: Diamond-like carbon (DLC) and carbon nitride (CN x ) bilayer films with Al and AlN interlayer were fabricated by pulse cathode arc technique. The structure, composition, morphology and mechanical properties of the films were investigated by Raman, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Knoop sclerometer and surface profilometer. The results indicated that the complete diffusion between C and Al atoms occurs in the Al/DLC and Al/CN x bilayer. Al interlayer induces the increase of the size and ordering of Csp 2 clusters in the films but AlN interlayer increases the disordering degree of Csp 2 clusters. XPS results showed that a higher content of Csp 3 /Csp 2 bonds presents in the Al/CN x bilayer, and Al and AlN interlayer decreases the atomic ratio of N/C. AFM with phase contrast mode illustrated the morphologic characteristics of the bilayer films. All the bilayers show a nano-structural surface. The morphology changes of the bilayer were well explained by the surface state of the substrate and the growth mechanism of DLC films. The hardness of Al/DLC bilayer decreases but it increases for the other bilayers compared to the corresponding DLC (CN x ) monolayer. The internal stress of the bilayer is significantly lower than that of the monolayer except for the AlN/CN x bilayer. These studies could make the difference at the time of choosing a suitable functional film for certain application

  8. Characteristics in AlN/AlGaN/GaN Multilayer-Structured High-Electron-Mobility Transistors

    International Nuclear Information System (INIS)

    Gui-Zhou, Hu; Ling, Yang; Li-Yuan, Yang; Si, Quan; Shou-Gao, Jiang; Ji-Gang, Ma; Xiao-Hua, Ma; Yue, Hao

    2010-01-01

    A new multilayer-structured AlN/AlGaN/GaN heterostructure high-electron-mobility transistor (HEMT) is demonstrated. The AlN/AlGaN/GaN HEMT exhibits the maximum drain current density of 800 mA/mm and the maximum extrinsic transconductance of 170 mS/mm. Due to the increase of the distance between the gate and the two-dimensional electron-gas channel, the threshold voltage shifts slightly to the negative. The reduced drain current collapse and higher breakdown voltage are observed on this AlN/AlGaN/GaN HEMT. The current gain cut-off frequency and the maximum frequency of oscillation are 18.5 GHz and 29.0 GHz, respectively. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    International Nuclear Information System (INIS)

    Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

    2013-01-01

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

  10. Cu-segregation at the Q'/α-Al interface in Al-Mg-Si-Cu alloy

    International Nuclear Information System (INIS)

    Matsuda, Kenji; Teguri, Daisuke; Uetani, Yasuhiro; Sato, Tatsuo; Ikeno, Susumu

    2002-01-01

    Cu segregation was detected at the Q ' /α-Al interface in an Al-Mg-Si-Cu alloy by energy-filtered transmission electron microscopy. By contrast, in a Cu-free Al-Mg-Si alloy no segregation was observed at the interface between the matrix and Type-C precipitate

  11. Effect of Al-5Ti-0.62C-0.2Ce Master Alloy on the Microstructure and Tensile Properties of Commercial Pure Al and Hypoeutectic Al-8Si Alloy

    Directory of Open Access Journals (Sweden)

    Wanwu Ding

    2017-06-01

    Full Text Available Al-5Ti-0.62C-0.2Ce master alloy was synthesized by a method of thermal explosion reaction in pure molten aluminum and used to modify commercial pure Al and hypoeutectic Al-8Si alloy. The microstructure and tensile properties of commercial pure Al and hypoeutectic Al-8Si alloy with different additions of Al-5Ti-0.62C-0.2Ce master alloy were investigated. The results show that the Al-5Ti-0.62C-0.2Ce alloy was composed of α-Al, granular TiC, lump-like TiAl3 and block-like Ti2Al20Ce. Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min can significantly refine macro grains of commercial pure Al into tiny equiaxed grains. The Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 30 min still has a good refinement effect. The tensile strength and elongation of commercial pure Al modified by the Al-5Ti-0.62C-0.2Ce master alloy (0.3 wt %, 5 min increased by roughly 19.26% and 61.83%, respectively. Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min can significantly refine both α-Al grains and eutectic Si of hypoeutectic Al-8Si alloy. The dendritic α-Al grains were significantly refined to tiny equiaxed grains. The morphology of the eutectic Si crystals was significantly refined from coarse needle-shape or lath-shape to short rod-like or grain-like eutectic Si. The tensile strength and elongation of hypoeutectic Al-8Si alloy modified by the Al-5Ti-0.62C-0.2Ce master alloy (1.5 wt %, 10 min increased by roughly 20.53% and 50%, respectively. The change in mechanical properties corresponds to evolution of the microstructure.

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

    Indian Academy of Sciences (India)

    and Ti-Al pre-alloyed powders at low temperature of 1150◦C. The composite mainly consisted ... Metal–matrix composites; mechanical properties; microstructures; sintering. 1. Introduction γ-TiAl-based intermetallic alloys have been extensively.

  13. Stagnation of the exploitation of Al ores and the depression of world prices of Al

    Directory of Open Access Journals (Sweden)

    Slavkovský Jozef

    1999-03-01

    Full Text Available In the contribution, data on Al – a metal of the 20th century are compiled together with the problems of genesis of the Al mineral raw ma-terials as well as types of bauxite and Al-laterite deposits. Furthermore, an overview of the world exploitation of bauxite during 1935-1980 is given along with the prognoses to 2000 and present situation (1992-1996. Overviews of the production of Al follows, providing its rela-tion to the bauxite exploitation. Contrary to the prognoses, a stabilization or stagnation has been observed in the exploitation of bauxite and production of Al during nineties, which a tendency is directly reflected in the world price of this commodity. When analyzing the Al prices for a longer period, some serious deviations can be noticed, that however presently represent a long-term minimum. We hope the stagnation of the production and the price decline are only temporary and new possibilities of the utilization of Al will be found soon.

  14. A study on preparation and hydriding of β-Mg2Al3 and γ-Mg17Al12

    International Nuclear Information System (INIS)

    Hadi Suwarno

    2009-01-01

    The mechanism of the synthetic formation of β-Mg 2 Al 3 and γ-Mg 17 Al 12 has been studied. Mechanical alloying of Mg and Al powders with the atomic ratio of Mg:Al = 2:3 in toluene solution yields β-Mg 2 Al 3 compound after milling for 30 h. The γ-Mg 17 Al 12 can be formed by heating the β-Mg 2 Al 3 at 430°C under high vacuum. The measured hydrogen capacities of β-Mg 2 Al 3 and γ-Mg 17 Al 12 as hydride at 300°C are 3.2 and 4.9 wt%, respectively. Microstructure of the Mg-Al specimen shows that on hydriding at 300°C the polygonal shape of the γ-Mg 17 Al 12 changes into irregular shapes which are composed of γ-MgH 2 and Al. (author)

  15. Marinbiologisk optegnelse i NUḪBAT AL-DAHR FĪ ʿAǦ ʾIB AL-BARR WA-AL-BAḤR

    OpenAIRE

    Provencal, Philippe

    2014-01-01

    I det arabiske geografiske værk NUḪBAT AL-DAHR FĪ ʿAǦ ʾIB AL-BARR WA-AL-BAḤR (færdigskrevet mellem 1324 og 1327) fra omtales seks dyr fra Adenbugten. Det dreje sig om savrokke, kuglefisk, pilrokke, pindsvinefisk og hvalhaj. Det sidste dyr har ikke kunnet bestemmes. Artiklen bringer en oversættelse af optegnelsen til engelsk samt både en filologisk som en biologisk kommentar. The aim of this article is to present a medieval Arabic report regarding sixanimals from the Gulf of Aden, to provid...

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

    Directory of Open Access Journals (Sweden)

    Imriyanti Imriyanti

    2014-02-01

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

  17. Adhesive and tribocorrosive behavior of TiAlPtN/TiAlN/TiAl multilayers sputtered coatings over CoCrMo

    Science.gov (United States)

    Canto, C. E.; Andrade, E.; Rocha, M. F.; Alemón, B.; Flores, M.

    2017-09-01

    The tribocorrosion resistance and adherence of multilayer coatings of TiAlPtN/TiAlN/TiAl synthesized by PVD reactive magnetron sputtering over a CoCrMo alloy substrate in 10 periods of 30 min each were analyzed and compared to those of the substrate alone and to that of a TiAlPtN single layer coating of the same thickness. The objective of the present work was to create multilayers with different amounts of Pt in order to enhance the tribocorrosion resistance of a biomedical alloy of CoCrMo. Tribocorrosion tests were performed using Simulated Body Fluid (SBF) at typical body temperature with a tribometer in a pin on disk test. The elemental composition and thickness of the coating which behave better at the tribocorrosion tests were evaluated by means of RBS (Rutherford Backscattering Spectroscopy) IBA (Ion Beam Analysis) technique, using an alpha particles beam of 1.8 MeV, before and after the reciprocating motion in the tribocorrosion test. In order to simulate the elemental profile of the samples, the SIMNRA simulation computer code was used. Measurements of the adhesion of the coatings to the substrate were carried on by means of a scratch test using a tribometer. By taking micrographs of the produced tracks, the critical loads at which the coatings are fully separated from the substrate were determined. From these tests it was observed that a coating with 10 min of TiAlPtN in a TiAlPtN/TiAl period of 30 min in multilayers of 10 periods and with an average thickness of 145 nm for the TiAlPtN nanolayers had the best tribocorrosion resistance behavior, compared to that of the CoCrMo alloy. The RBS experiments showed a reduction of the thickness of the films along with some loss of the multilayer structure after the reciprocating motion. The adhesion tests indicated that the multilayer with the average TiAlPtN thickness of 145 nm displayed the highest critical load. These results indicate a high correlation between the adherence and the tribocorrosion behavior.

  18. Microstructure of Reaction Zone Formed During Diffusion Bonding of TiAl with Ni/Al Multilayer

    Science.gov (United States)

    Simões, Sónia; Viana, Filomena; Koçak, Mustafa; Ramos, A. Sofia; Vieira, M. Teresa; Vieira, Manuel F.

    2012-05-01

    In this article, the characterization of the interfacial structure of diffusion bonding a TiAl alloy is presented. The joining surfaces were modified by Ni/Al reactive multilayer deposition as an alternative approach to conventional diffusion bonding. TiAl substrates were coated with alternated Ni and Al nanolayers. The nanolayers were deposited by dc magnetron sputtering with 14 nm of period (bilayer thickness). Joining experiments were performed at 900 °C for 30 and 60 min with a pressure of 5 MPa. Cross sections of the joints were prepared for characterization of their interfaces by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), high resolution TEM (HRTEM), energy dispersive x-ray spectroscopy (EDS), and electron backscatter diffraction (EBSD). Several intermetallic compounds form at the interface, assuring the bonding of the TiAl. The interface can be divided into three distinct zones: zone 1 exhibits elongated nanograins, very small equiaxed grains are observed in zone 2, while zone 3 has larger equiaxed grains. EBSD analysis reveals that zone 1 corresponds to the intermetallic Al2NiTi and AlNiTi, and zones 2 and 3 to NiAl.

  19. Al-quran dalam Perspektif Budaya

    OpenAIRE

    Sudrajat, Ajat

    2009-01-01

    Al-Quran merupakan kitab suci terakhir yang diturunkan kepada manusia. Tujuan utama diturunkannya al-Quran adalah sebagai kitab petunjuk yang meliputi bidang akidah, syariah, dan akhlak. Akan tetapi di luar ketiga petunjuk tersebut, al-Quran telah memberikan motivasi dan inspirasi kepada umat Islam dalam berbagai bidang kehidupan sehingga melahirkan jenis budaya tertentu. Dialog intelektual yang dilakukan secara kreatif oleh umat Islam terhadap al-Quran ternyata telah menghasilkan lahirnya ge...

  20. ITIJAHAT KAUN AL-NABI WA AL-RASUL FI SYAKHSIYAH MUHAMMAD FI NATSR MAULID AL-BARZANJI

    Directory of Open Access Journals (Sweden)

    Himmah Istomah

    2017-08-01

    Full Text Available One of human personalities is humanist. Based on the understanding of Maslow’s theory of motivation, researcher seeks to uncover kinds of motivational needs of Muhammad Saw contained in Maulid Al-Barzanjiy (the work of Ja 'far bin Hasan al-Barzanji (d. 1763 M. The goal is realized through a descriptive qualitative approach with  text analysis  about Psycholiterature of Endraswara. The results of this study indicate that in Maulid Al-Barzanji there are Muhammad Saw’s five needs and how their satisfying perfectly,  namely: physiological needs, safety, social, esteem, and self-actualization. Thus, it can be interpreted that Muhammad SAW as an ordinary human having motivational needs. His prophetic and apostleship honor is not a direct blessing from Allah, but he had been through some complicated processes in life. This can be applied by his followers, so they can complete their motivational needs to reach the satiation as a caliph and to be useful person in this world.

  1. Microstructure and bonding mechanism of Al/Ti bonded joint using Al-10Si-1Mg filler metal

    International Nuclear Information System (INIS)

    Sohn, Woong H.; Bong, Ha H.; Hong, Soon H.

    2003-01-01

    The microstructures and liquid state diffusion bonding mechanism of cp-Ti to 1050 Al using an Al-10.0wt.%Si-1.0wt.%Mg filler metal with 100 μm in thickness have been investigated at 620 deg. C under 1x10 -4 Torr. The effects of bonding process parameters on microstructure of bonded joint have been analyzed by using an optical microscope, AES, scanning electron microscopy and EDS. The interfacial bond strength of Al/Ti bonded joints was measured by the single lap shear test. The results show that the bonding at the interface between Al and filler metal proceeds by wetting the Al with molten filler metal, and followed by removal of oxide layer on surface of Al. The interface between Al and filler metal moved during the isothermal solidification of filler metal by the diffusion of Si from filler metal into Al layer. The interface between Al and filler metal became curved in shape with increasing bonding time due to capillary force at grain boundaries. The bonding at the interface between Ti and filler metal proceeds by the formation of two different intermetallic compound layers, identified as Al 5 Si 12 Ti 7 and Al 12 Si 3 Ti 5 , followed by the growth of the intermetallic compound layers. The interfacial bond strength at Al/Ti joint increased with increasing bonding time up to 25 min at 620 deg. C. However, the interfacial bond strength of Al/Ti joint decreased after bonding time of 25 min at 620 deg. C due to formation of cavities in Al near Al/intermetallic interfaces

  2. Micromechanisms of fracture and fatigue in Ti3Al based and TiAl based intermetallics

    International Nuclear Information System (INIS)

    James, A.W.; Chave, R.A.; Hippsley, C.A.; Bowen, P.

    1993-01-01

    Micromechanisms of fracture and fatigue crack growth resistance in specific Ti 3 Al based and TiAl based intermetallics are reviewed. Effects of test temperature, environment and microstructure on crack growth resistance are considered in detail for several Ti 3 Al and Ti'Al based intermetallic systems under development. The implications of these studies for the structural reliability of these materials is also addressed briefly. (orig.)

  3. Core electron binding energy shifts of AlBr3 and Al2Br6 vapor

    International Nuclear Information System (INIS)

    Mueller, Astrid M.; Plenge, Juergen; Leone, Stephen R.; Canton, Sophie E.; Rude, Bruce S.; Bozek, John D.

    2006-01-01

    The Al 2p and Br 3d inner-shell photoelectron spectra of aluminum tribromide monomer and dimer vapor were measured at 90 and 95 eV photon energy, respectively, to determine the core electron binding energies of the atoms in the two molecular species. While AlBr 3 has three identical Br atoms, Al 2 Br 6 exhibits four terminal and two bridging Br atoms. The species are identified by their distinct valence photoelectron spectra. Comparison of the observed Al 2p 1/2 and Al 2p 3/2 electron binding energies of AlBr 3 with those of Al 2 Br 6 shows that there is a chemical shift of (0.15 ± 0.03) eV to lower energy in the dimer. In Al 2 Br 6 , an assignment is proposed in which the Br 3d 3/2 and Br 3d 5/2 binding energies of terminal Br atoms are (1.18 ± 0.03) eV lower than those of bridging Br atoms. This assignment assumes that both types of Br atoms have similar cross-sections for ionization. With this result, the Br 3d 3/2 and Br 3d 5/2 binding energies of Br atoms in AlBr 3 are (0.81 ± 0.03) eV lower than those of bridging Br atoms of the dimer but (0.37 ± 0.03) eV higher than those of terminal Br atoms of the dimer. The obtained chemical shifts are considered in terms of the binding relations and electron density distributions in both molecules. Chemical shifts that are larger than a few hundred millielectron volts, as observed in the Al 2 Br 6 /AlBr 3 system, offer potential to study the dissociation dynamics of the dimer in a femtosecond visible or ultraviolet-pump/XUV-probe experiment

  4. PENDEKATAN HERMENEUTIK DALAM PEMAHAMAN HADIS (Kajian Kitab Fath al-Bari Karya Ibn Hajar Al-‘Asqalani

    Directory of Open Access Journals (Sweden)

    Agusni Yahya

    2014-12-01

    Full Text Available The hadith explanation book of Sahih al-Bukhari written by Ibn Hajar Al-‘Asqalani, Fath al-Bari, is one of the most pupular books in Moslem ummah. Is widely used by Moslem scholars to meet the meanings of hadiths compiled by the imam al-Bukhari in his Sahih al-Bukhari. Fath al-Bari is considered significant to do the research on it in order to develop the science of hadith, mainly through the hermeneutic method. By using this method, the research questions are: 1. How does Ibn Hajar Al-‘Asqalani explain the matans (hadith texts of Sahih al Bukhari in connection with hermeneutic method? 2. What are the hermeneutic principles used by Ibn Hajar Al-‘Asqalani in his explanations of hadith? This research is expected to respond the research questions above so that it can be implimented the field of hadith in relation to develop hadith methodology. Finally, the research uncover that in his explanations of hadiths,  Ibn Hajar Al-‘Asqalani is oriented his world views to the classical Islam, the era of Prophet’s companions and their successors, the Salaf al-Salih. He does not express the Islamic world issues available in his time in his explanations of the hadiths. He is considered a normative ‘ulama since he is not influenced by the emerging cases situated his time in Egypt, Mecca and Madina. He tends to be textual to explain the matans of hadiths although to some extent he uncovers the historical contexts of the hadiths he explains. This is common for a muhadith  whose main jobs is to collect and narrate the whole data on Prophet's sayings, acts and permissions either on sanads (narrators or matans (texts.Keywords:  Fath al-Bari; sharh al-hadith; hermeneutik.

  5. Les usages du sucre dans le manuel de pharmacie de Cohen al-‘Aṭṭār médecin juif du Caire au XIIIe siècle

    Directory of Open Access Journals (Sweden)

    Ouerfelli, Mohamed

    2013-06-01

    Full Text Available In the absence of a pharmaceutical guide for the usage of apothecaries and merchants of drugs and drinks, which took into account the evolution of pharmacy and the development of pharmaceutical products, Cohen al-‘Aṭṭar wrote a new manual in which he reminded us not only of the writings of his predecessors, but also the point of view of his contemporaries, notably his proper experiences he carried out in his shop in Cairo to make pharmaceutical products and the means to preserve them. This pharmaceutical manual, the richest in medicine formulas, also stands out on account of the extensive use of sugar in the making of recipes. Given the fact that this product was available in large quantities in Egypt and Syria during the second half of the 13th century, it gradually substituted honey to become the principal ingredient in the making of drugs and drinks. Thus, sugar broke through the food world to become the privilege of the royal class, who turned it into one of the essential elements for their festivities.[fr] Face à l’absence d’un guide pharmaceutique à l’usage des apothicaires et des marchands de drogues et de boissons, qui tient compte de l’évolution de la pharmacie et du développement de la matière médicale, Cohen al-‘Aṭṭār propose un nouveau manuel dans lequel il rappelle non seulement les écrits de ses prédécesseurs, mais il livre également les points de vue de ses contemporains, et surtout ses propres expériences, qu’il mène dans sa boutique du Caire, pour la confection des médicaments et les moyens de les conserver. Ce manuel pharmaceutique, le plus riche en formules médicamenteuses, se distingue également par l’usage massif du sucre dans l’élaboration des recettes. Ce produit, disponible en grandes quantités en Égypte et en Syrie pendant la seconde moitié du XIIIe siècle, se substitue progressivement au miel et devient l’ingrédient principal dans l’élaboration des médicaments et des

  6. Empleo racional de la coronectomía en la extracción de terceros molares incluidos Rational application of coronectomy when treating lower impacted third molar

    Directory of Open Access Journals (Sweden)

    C. Recio Lora

    2009-08-01

    Full Text Available Los terceros molares son los dientes que, con más frecuencia, sufren el fracaso de su erupción y quedan incluidos o retenidos dentro de los maxilares. Un gran porcentaje de nuestros pacientes presentan los cordales incluidos y, de ellos, una parte importante se acompaña de patología que hace aconsejable su tratamiento quirúrgico. La técnica de la coronectomía aplicada al tercer molar incluido fue descrita por primera vez por Ecuyer y Debien en 1984 como la eliminación parcial de dicho diente, dejando deliberadamente parte de su raíz en el interior de la mandíbula. Fue propuesta para evitar la lesión del nervio dentario inferior (NDI en aquéllos casos en los que existía una íntima relación entre ambas estructuras anatómicas. Aunque el objetivo de la técnica es muy claro, no está libre de controversia, ya que el cirujano debe valorar la posibilidad de una complicación infecciosa de origen pulpar. Presentamos un caso clínico exitoso de esta técnica, junto al análisis de la postura ante la técnica de los distintos autores, así como sus ventajas e inconvenientes.Third molars are the teeth that most frequently fail to erupt and remain impacted or retained inside the bone. A large percentage of our patients have impacted wisdom teeth and many of these patients also have pathologies that require surgical treatment. Applied coronectomy technique of the impacted third molar was first described by Ecuyer and Debien in 1984. The described it as partial elimination of the tooth in question, deliberately leaving part of the root inside the bone. This was proposed to avoid injuring the inferior dental nerve in cases where there was a close relationship between the two anatomical structures. Although the objective of the procedure is very clear, it is still controversial. Therefore, the surgeon should evaluate the possibility of an infectious complication of pulpar origin. We present the successful clinical case that uses this technique

  7. Nave de montaje Volkswagen, Venezuela

    Directory of Open Access Journals (Sweden)

    Bornhorst, D.

    1966-02-01

    Full Text Available To assemble Volkswagen cars for the Venezuela market, a large hall has been built, which is fitted with full facilities for its purpose, such as painting and greasing installations, and large parking area for the finished vehicles. The siting of this hall was carefully studied, and such factors as nearness to industrial zones, climate, and ease of access were decisive aspects that were taken into account. The final choice was a site near Morón, in the Carabobo Department, close to the sea. The main constructional item is the roof of the large hall. It is made of a series of hyperbolic-parabolic reinforced concrete thin shells, of rectangular planform, and slightly inclined towards the north, to produce a saw edge profile. Each of these shells is supported by a central column. The hollow spaces along the saw edge profile have been used for ventilation. The enclosing walls consist of trellice material, which also provide ample facility for additional ventilation.Para el montaje de los coches Volkswagen destinados al mercado venezolano, se ha construido una gran nave dotada de todos los servicios necesarios: pintura, engrases, aparcamiento de los vehículos terminados, etc. La elección del lugar más apropiado para la situación de la nave y edificios anexos fue motivo de un detenido estudio, en el que la proximidad a zonas industriales, clima, fácil entrada de materiales procedentes de ultramar y salida para los acabados, fueron los factores decisivos. Definitivamente se eligió un solar en las cercanías de Morón, del departamento de Carabobo, y próximo al mar. Lo más notable es la cubierta de la gran nave, formada por una serie de láminas parabólico-hiperbólicas de hormigón armado, de planta rectangular, inclinadas ligeramente hacia el norte para formar un perfil en diente de sierra. Cada una de estas láminas se soporta por un montante central. Los huecos que dichos dientes de sierra dejan se han aprovechado para la ventilación. Los

  8. Thermophysical properties of αAl2O3, MgAl2O4 and AlN at low tempertures

    International Nuclear Information System (INIS)

    Burghartz, S.

    1995-12-01

    A possibility for producing energy in future might be the nuclear fusion. The process of nuclear fusion is characterized by melting nuclei of hydrogen atoms (deuterium and tritium) which yield to the production of helium atom nuclei. For this process extremely high temperatures of the deuterium-tritium-gas plasma are necessary. The additional heating of the plasma by microwaves requires materials with low diaelectric losses and high thermal conductivity. The thermal conductivity can be increased by cooling the windows which lead to the plasma chambre. Experimental investigations with the aim to check the influence of liquid nitrogen (T=70 K) on the cooling of the windows were performed in the temperature region 70 K 2 O 3 , MgAl 2 O 4 and AlN were measured. The thermal conductivity can be calculated using the equation λ=αc p ρ λ=thermal conductivity α=thermal diffusivity c p =specific heat (at constant pressure) ρ=density. Furthermore a theoretical method to calculate the thermal conductivity at low temperatures is presented; this is done by using a model modification of heat transport in electric insulators. As result the influence of intrinsic parameters (crystal structure, interatomar binding, anharmonicity) and extrinsic parameters (point defects, dislocations, boundary areas) upon thermal conductivity of α-Al 2 O 3 , MgAl 2 O 4 and AlN are achieved. (orig.)

  9. Grain refinement of Al wrought alloys with newly developed AlTiC master alloys; Kornfeinung von Al-Knetlegierungen mit neu entwickelten AlTiC-Vorlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, W. [Vereinigte Aluminium-Werke AG, Bonn (Germany). Forschung und Entwicklung

    2000-10-01

    AlTiC master alloys are a new grain refiner type to produce an equiaxed grain structure of cast extrusion and rolling ingots. These master alloys contain Ti carbides which act as nucleants of the {alpha} solid solution during solidification. The TiC content is lower than the TiB{sub 2} content of the industrial proved AlTiB master alloys. Benefits of the AlTiC master alloys are the low agglomeration tendency of the Ti carbides in the melt and that no Zr poisoning takes place. Despite of the low Ti carbide content the grain refinement performance can be very efficient, if low melt temperatures during casting will be used and as result of this a sufficient constitutional supercooling at the solidification front is achieved. (orig.)

  10. Advanced life support (ALS) instructors experience of ALS education in Western Australia: a qualitative exploratory research study.

    Science.gov (United States)

    Taplin, John; McConigley, Ruth

    2015-04-01

    When cardiac arrest occurs, timely competent advanced life support (ALS) interventions by nursing staff can influence patient outcomes. Ongoing ALS education influences maintenance of competency and avoids skill decay. To explore the methods of ALS education delivery for nurses in the workplace; describe the issues relating to maintaining ALS competency; explore ALS competency decay for nurses and develop recommendations for the provision of continuing ALS education. A qualitative exploratory design was used to study ALS education provision in the workplace. Data were collected from ALS nurse experts in Western Australia by face-to-face and phone interviews. Semi-structured interviews were conducted and organised around a set of predetermined questions. Two major themes were identified; the first theme Demand and Supply describes the increasing demand for ALS education for nurses and the challenges with providing timely cost effective traditional face-to-face ALS education. The second theme, Choosing The Best Education Options describes new ways to provide ALS education using emerging technologies. The study suggested that using e-learning methods would assist with educating the maximum amount of nurses in a timely manner and e-learning and teleconferencing offer opportunities to reach nurses in distant locations. Delivering ALS education more frequently than annually would increase skills maintenance and lessen skill decay. Further research is required to explore which blended e-learning model is best suited to ALS education. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Al-Qaeda-Syria (AQS): An Al-Qaeda Affiliate Case Study

    Science.gov (United States)

    2017-10-01

    Special Operations/Low Intensity Conflict CT Counterterrorism FF Foreign Fighter FSA Free Syrian Army GEC Global Engagement Center HTS Hay’at...war as an opportunity for the global jihadist movement, an opportunity that paralleled the one Iraq had offered a decade earlier.11 He was initially...Zawahiri’s vision of Al-Qaeda franchises oriented toward winning popular support. When al-Zawahiri published his “General Guidelines for Jihad” in

  12. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    International Nuclear Information System (INIS)

    Qu, Jun; He, Xiaoman; Chen, Min; Hu, Huimin; Zhang, Qiwu; Liu, Xinzhong

    2017-01-01

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu_2(OH)_2CO_3) and aluminum hydroxide (Al(OH)_3) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  13. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun, E-mail: forsjun@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); He, Xiaoman; Chen, Min; Hu, Huimin [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Zhang, Qiwu, E-mail: zhangqw@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Liu, Xinzhong [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118 China (China)

    2017-04-15

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu{sub 2}(OH){sub 2}CO{sub 3}) and aluminum hydroxide (Al(OH){sub 3}) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  14. Superstructure formation in PrNi_2Al_3 and ErPd_2Al_3

    International Nuclear Information System (INIS)

    Eustermann, Fabian; Hoffmann, Rolf-Dieter; Janka, Oliver; Oldenburg Univ.

    2017-01-01

    The intermetallic phase ErPd_2Al_3 was obtained by arc-melting of the elements and subsequent annealing for crystal growth. The sample was studied by X-ray diffraction on powders and single crystals. The structure of ErPd_2Al_3 was refined from X-ray diffraction data and revealed a superstructure of PrNi_2Al_3 - a CaCu_5 derivative (P6/m, a=1414.3(1), c=418.87(3) pm wR=0.0820, 1060 F"2 values, 48 variables). The same superstructure was subsequently found for PrNi_2Al_3 (P6/m, a=1407.87(4), c=406.19(2) pm, wR=0.0499, 904 F"2 values, 47 variables). In the crystal structure, the aluminium and transition metal atoms form a polyanionic network according to [T_2Al_3]"δ"-, while rare earth atoms fill cavities within the networks. They are coordinated by six transition metal and twelve aluminum atoms. In contrast to the PrNi_2Al_3 type structure reported so far, two crystallographic independent rare-earth sites are found of which one (1b) is shifted by 1/2 z, causing a distortion in the structure along with a recoloring of the T and Al atoms in the network.

  15. Reevaluación del paciente periodontal: intervalo de tiempo adecuado para reevaluar sus parámetros

    Directory of Open Access Journals (Sweden)

    Berenice Flores Díaz

    2017-07-01

    Full Text Available La reevaluación es uno de los pasos del tratamiento periodontal enfocados en determinar los resultados de la terapia inicial y la necesidad de terapias de soporte adicionales. El objetivo del artículo es revisar la información relacionada al intervalo de tiempo para la reevaluación los signos de progresión de la enfermedad periodontal apropiado para medir los efectos de la terapia inicial. Después de este período de tiempo, la estabilidad del periodonto debe ser evaluada en lugar de los efectos de la terapia. Conclusión: En síntesis el establecimiento de la nueva unión dento-epitelial se realiza de manera rutinaria por lo que se sugiere la reevaluación después de 2 semanas. Luego del raspado y alisado radicular hay restablecimiento del epitelio de unión al diente la super cie en 1 a 2 semanas el tejido conjuntivo continúa durante 4 a 8 semanas pero más de 2 meses puede ser demasiado tiempo porque las bacterias patógenas ya han repoblado las bolsas periodontales.

  16. 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...

  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. Deformation mechanisms of nanotwinned Al

    International Nuclear Information System (INIS)

    Zhang, Xinghang

    2016-01-01

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

  19. Study on Microstructure and Mechanical Properties of Hypereutectic Al-18Si Alloy Modified with Al-3B.

    Science.gov (United States)

    Gong, Chunjie; Tu, Hao; Wu, Changjun; Wang, Jianhua; Su, Xuping

    2018-03-20

    An hypereutectic Al-18Si alloy was modified via an Al-3B master alloy. The effect of the added Al-3B and the modification temperature on the microstructure, tensile fracture morphologies, and mechanical properties of the alloy were investigated using an optical microscope, Image-Pro Plus 6.0, a scanning electron microscope, and a universal testing machine. The results show that the size of the primary Si and its fraction decreased at first, and then increased as an additional amount of Al-3B was added. When the added Al-3B reached 0.2 wt %, the fraction of the primary Si in the Al-18Si alloy decreased with an increase in temperature. Compared with the unmodified Al-18Si alloy, the tensile strength and elongation of the alloy modified at 850 °C with 0.2 wt % Al-3B increased by 25% and 81%, respectively. The tensile fracture of the modified Al-18Si alloy exhibited partial ductile fracture characteristics, but there were more areas with ductile characteristics compared with that of the unmodified Al-18Si alloy.

  20. 26Mg(p,n)26Al and 23Na(α,n)26Al reactions

    International Nuclear Information System (INIS)

    Skelton, R.T.

    1985-01-01

    Cross sections for the 26 Mg(p,n) 26 Al reaction were measured from threshold at 4.988 MeV to 5.820 MeV. Cross sections for the 23 Na(α,n) 26 Al reaction were measured from threshold at 3.483 MeV to 4.597 MeV. In each case, separate measurements were to the ground state and to the first and second excited states of 26 Al. Cross sections for the inverse reactions were calculated and reaction rate factors relating to the destruction of 26 Al in a supernova environment were determined. Astrophysical implications relating to the observation of live and extinct 26 Al are discussed. Excitation functions for several additional exit channels for the 26 Mg + rho and 23 Na + α reactions are reported

  1. effect of the parameters of AlN/GaN/AlGaN and AlN/GaN/InAlN heterostructures with a two-dimensional electron gas on their electrical properties and the characteristics of transistors on their basis

    Energy Technology Data Exchange (ETDEWEB)

    Tsatsulnikov, A. F., E-mail: andrew@beam.ioffe.ru [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation); Lundin, V. W.; Zavarin, E. E.; Yagovkina, M. A.; Sakharov, A. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation); Usov, S. O. [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation); Zemlyakov, V. E.; Egorkin, V. I. [National Research University of Electronic Technology (MIET) (Russian Federation); Bulashevich, K. A.; Karpov, S. Yu. [“Soft-Impact” Ltd. (Russian Federation); Ustinov, V. M. [Russian Academy of Sciences, Submicron Heterostructures for Microelectronics Research and Engineering Center (Russian Federation)

    2016-10-15

    The effect of the layer thickness and composition in AlGaN/AlN/GaN and InAlN/AlN/GaN transistor heterostructures with a two-dimensional electron gas on their electrical and the static parameters of test transistors fabricated from such heterostructures are experimentally and theoretically studied. It is shown that the use of an InAlN barrier layer instead of AlGaN results in a more than twofold increase in the carrier concentration in the channel, which leads to a corresponding increase in the saturation current. In situ dielectric-coating deposition on the InAlN/AlN/GaN heterostructure surface during growth process allows an increase in the maximum saturation current and breakdown voltages while retaining high transconductance.

  2. Fabrication and thermal characterization of amorphous and nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti compound

    Energy Technology Data Exchange (ETDEWEB)

    Tavoosi, Majid, E-mail: ma.tavoosi@gmail.com

    2017-01-15

    In this study, the fabrication and structural characterization of amorphous/nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti phase has been performed. In this regards, milling and annealing processes were applied on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} (at. %) powder mixture for different periods of time. The prepared samples were characterized using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM) and differential scanning calorimetery (DSC). According to the results, supersaturated solid solution, nanocrystalline Al{sub 9}FeNi/Al{sub 3}Ti (with average crystallite size of about 7 nm) and amorphous phases indicated three different microstructures which can be formed in Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} system during milling process. The formed supersaturated solid solution and amorphous phases were unstable and transformed to Al{sub 9}FeNi/Al{sub 3}Ti intermetallic compound during annealing process. It is shown that, Al{sub 9}FeNi phase in Al{sub 9}FeNi/Al{sub 3}Ti intermetallic compound can decompose into Al{sub 3}Ni, Al{sub 13}Fe{sub 4} and liquid phases during a reversible peritectic reaction at 809 °C. - Highlights: • We study the effect of milling process on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} alloy. • We study the effect of annealing on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} supersaturated solid solution phase. • We study the effect of annealing on Al{sub 80}Fe{sub 10}Ti{sub 5}Ni{sub 5} amorphous phase. • We study the thermal behaviour of Al{sub 9}FeNi/Al{sub 3}Ti compound.

  3. Computer aided cooling curve analysis for Al-5Si and Al-11Si alloys ...

    African Journals Online (AJOL)

    The effect of grain refiner, modifier, and combination of grain refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both grain refiner and modifier.

  4. AL-USRCRN Station Information

    Data.gov (United States)

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

  5. Gd3+-ESR and magnetic susceptibility of GdCu4Al8 and GdMn4Al8

    International Nuclear Information System (INIS)

    Coldea, R.; Coldea, M.; Pop, I.

    1994-01-01

    Gd ESR of GdCu 4 Al 8 and GdMn 4 Al 8 and magnetic susceptibility of GdCu 4 Al 8 , GdMn 4 Al 8 , and YMn 4 Al 8 were measured in the temperature range of 290K--460K and 90K--1050K, respectively. The occurrence of the Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 is strongly correlated with the critical value of d∼2.6 angstrom of the Mn-Mn distance below which the Mn moment is not stable. The experimental data for GdMn 4 Al 8 , compared with the data for the isostructural compounds GdCu 4 Al 8 and YMn 4 Al 8 , show that near the critical value of d, the existence of Mn moment depends not only on the value of d, but also on the local magnetic surroundings. It has been revealed that the magnetic character of Mn moment in YMn 4 Al 8 and GdMn 4 Al 8 changes from an itinerant electron type to a local-moment type with increasing temperature

  6. Effect of AlB2-Mg interaction on the mechanical properties of Al-based composites

    International Nuclear Information System (INIS)

    Calderon, Hermes E.; Hidalgo, Ruth G.I.; Melgarejo, Z. Humberto; Suarez, O. Marcelo

    2010-01-01

    A series of Al-based composites with a matrix containing 2.5 wt.%Cu and 1 wt.%Mg, and reinforced with Al diborides was manufactured and characterized via microscopy and mechanical testing. The impact resistance of the composites revealed interaction between AlB 2 dispersoids and Mg originally present in the Al matrix. An unexpected increase in the absorbed impact energy of composites with diborides prompted complementary experiments leading to this finding. Hardness tests were correlated to those results and provided further evidence of the interaction between Mg and the dispersoids. Additional energy dispersive spectroscopy (EDS) analysis and X-ray diffraction tests supported with crystal modeling demonstrated that Mg effectively diffused into the AlB 2 crystal producing a doped structure with an Al 1-x Mg x B 2 formula where x lies between 0.08 and 0.15.

  7. Potential skin involvement in ALS: revisiting Charcot's observation - a review of skin abnormalities in ALS.

    Science.gov (United States)

    Paré, Bastien; Gros-Louis, François

    2017-07-26

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motor neurons of the brain and spinal cord, leading to progressive paralysis and death. Interestingly, many skin changes have been reported in ALS patients, but never as yet fully explained. These observations could be due to the common embryonic origin of the skin and neural tissue known as the ectodermal germ layer. Following the first observation in ALS patients' skin by Dr Charcot in the 19th century, in the absence of bedsores unlike other bedridden patients, other morphological and molecular changes have been observed. Thus, the skin could be of interest in the study of ALS and other neurodegenerative diseases. This review summarizes skin changes reported in the literature over the years and discusses about a novel in vitro ALS tissue-engineered skin model, derived from patients, for the study of ALS.

  8. Effects of O in a binary-phase TiAl-Ti3Al alloy: from site occupancy to interfacial energetics

    International Nuclear Information System (INIS)

    Wei Ye; Xu Huibin; Zhou Hongbo; Zhang Ying; Lu Guanghong

    2011-01-01

    We have investigated site occupancy and interfacial energetics of a TiAl-Ti 3 Al binary-phase system with O using a first-principles method. Oxygen is shown to energetically occupy the Ti-rich octahedral interstitial site, because O prefers to bond with Ti rather than Al. The occupancy tendency of O in TiAl alloy from high to low is α 2 -Ti 3 Al to the γ-α 2 interface and γ-TiAl. We demonstrate that O can largely affect the mechanical properties of the TiAl-Ti 3 Al system. Oxygen at the TiAl-Ti 3 Al interface reduces both the cleavage energy and the interface energy, and thus weakens the interface strength but strongly stabilizes the TiAl/Ti 3 Al interface with the O 2 molecule as a reference. Consequently, the mechanical property variation of TiAl alloy due to the presence of O not only depends on the number of TiAl/Ti 3 Al interfaces but also is related to the O concentration in the alloy.

  9. A study on wear resistance and microcrack of the Ti{sub 3}Al/TiAl + TiC ceramic layer deposited by laser cladding on Ti-6Al-4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li Jianing, E-mail: ljnljn1022@163.com [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China); Chen Chuanzhong [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China); Squartini, Tiziano [INFM-Department of Physics, Siena University, Siena 53100 (Italy); He Qingshan [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Department of Materials Science, Shandong University, Jing Shi Road 17923, Jinan 250061, Shandong (China)

    2010-12-15

    Laser cladding of the Al + TiC alloy powder on Ti-6Al-4V alloy can form the Ti{sub 3}Al/TiAl + TiC ceramic layer. In this study, TiC particle-dispersed Ti{sub 3}Al/TiAl matrix ceramic layer on the Ti-6Al-4V alloy by laser cladding has been researched by means of X-ray diffraction, scanning electron microscope, electron probe micro-analyzer, energy dispersive spectrometer. The main difference from the earlier reports is that Ti{sub 3}Al/TiAl has been chosen as the matrix of the composite coating. The wear resistance of the Al + 30 wt.% TiC and the Al + 40 wt.% TiC cladding layer was approximately 2 times greater than that of the Ti-6Al-4V substrate due to the reinforcement of the Ti{sub 3}Al/TiAl + TiC hard phases. However, when the TiC mass percent was above 40 wt.%, the thermal stress value was greater than the materials yield strength limit in the ceramic layer, the microcrack was present and its wear resistance decreased.

  10. Synthesis behavior of nanocrystalline Al-Al2O3 composite during low time mechanical milling process

    International Nuclear Information System (INIS)

    Alizadeh, Mostafa; Aliabadi, Morteza Mirzaei

    2011-01-01

    Research highlights: → In the low time milling the effect of Al 2 O 3 amount is investigated → Al 2 O 3 particles are distributed uniformly in the Al matrix → In the low time milling it is possible to produce nanostructured composite powder → Median size and bulk density measurements demonstrate reaching the steady state. - Abstract: In this work, four different volume fractions of Al 2 O 3 (10, 20, 30 and 40 vol.%) were mixed with the fine Al powder and the powder blends were milled for 5 h. Scanning electron microscopy analysis, particle size analysis and bulk density measurements were used to investigate the morphological changes and achieving the steady state conditions. The results showed that increasing the Al 2 O 3 content can provide the steady state particle size in 5 h milling process. It was found that increasing the volume fraction of Al 2 O 3 leads to increasing the uniformity of Al 2 O 3 . Standard deviations of microhardness measurements confirmed this result. The XRD pattern and XRF investigations depicted that increasing the Al 2 O 3 content causes an increase in the crystal defects, micro-strain and Fe contamination during 5 h milling process of nanocrystalline composite powders while the grain size is decreased. To investigate the effect of milling time, Al-30 vol.% Al 2 O 3 (which achieved steady state during 5 h milling process) was milled for 1-4 h. The results depicted that the milling time lower than 5 h, do not achieve to steady state conditions.

  11. Study of the ternary alloy systems Al-Ni-Fe and Al-Cu-Ru with special regard to quasicrystalline phases

    International Nuclear Information System (INIS)

    Lemmerz, U.

    1996-07-01

    Two ternary alloy-systems, the Al-Ni-Fe system and the Al-Cu-Ru system were studied with special regard to quasicrystalline phases. Isothermal sections were established in both systems in the stoichiometric area of the quasicrystalline phase. In the Al-Ni-Fe system a new stable decagonal phase was found. Its stoichiometric range is very small around Al 71.6 Ni 23.0 Fe 5.4 . The temperature range in which it is stable lies between 847 and 930 C. The decagonal phase undergoes a eutectoid reaction to the three crystalline phases Al 3 Ni 2 , Al 3 Ni and Al 13 Fe 4 at 847 C. It melts peritectically at 930 C forming Al 13 Fe 4 , Al 3 Ni 2 and a liquid. The investigations in the Al-Cu-Ru system concentrated on the phase equilibria between the icosahedral phase and its neighbouring phases in a temperature range between 600 and 1000 C. The icosahedral phase was observed in the whole temperature range. The investigated stoichiometric area extends down to Al contents of 45%, which allows the fields of existence to be determined for the ternary phases α-AlCuRu, the icosahedral phase and Al 7 Cu 2 Ru. Binary phases were determined down to the upper (high Al content) border of AlRu. No hitherto unknown phase was observed in the investigated area. Rietveld analyses were carried out on α-AlCuRu and Al 7 Cu 2 Ru showing some discrepancies from the α-AlMnSi structure taken as a base for α-AlCuRu and confirming the Al 7 Cu 2 Fe structure for Al 7 Cu 2 Ru. (orig.)

  12. Al-Cu-Li and Al-Mg-Li alloys: Phase composition, texture, and anisotropy of mechanical properties (Review)

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Knyazev, M. I.

    2016-04-01

    The results of studying the phase transformations, the texture formation, and the anisotropy of the mechanical properties in Al-Cu-Li and Al-Mg-Li alloys are generalized. A technique and equations are developed to calculate the amounts of the S1 (Al2MgLi), T1 (Al2CuLi), and δ' (Al3Li) phases. The fraction of the δ' phase in Al-Cu-Li alloys is shown to be significantly higher than in Al-Mg-Li alloys. Therefore, the role of the T1 phase in the hardening of Al-Cu-Li alloys is thought to be overestimated, especially in alloys with more than 1.5% Li. A new model is proposed to describe the hardening of Al-Cu-Li alloys upon aging, and the results obtained with this model agree well with the experimental data. A texture, which is analogous to that in aluminum alloys, is shown to form in sheets semiproducts made of Al-Cu-Li and Al-Mg-Li alloys. The more pronounced anisotropy of the properties of lithium-containing aluminum alloys is caused by a significant fraction of the ordered coherent δ' phase, the deformation mechanism in which differs radically from that in the solid solution.

  13. Strain Balanced AlGaN/GaN/AlGaN nanomembrane HEMTs.

    Science.gov (United States)

    Chang, Tzu-Hsuan; Xiong, Kanglin; Park, Sung Hyun; Yuan, Ge; Ma, Zhenqiang; Han, Jung

    2017-07-25

    Single crystal semiconductor nanomembranes (NM) are important in various applications such as heterogeneous integration and flexible devices. This paper reports the fabrication of AlGaN/GaN NMs and NM high electron mobility transistors (HEMT). Electrochemical etching is used to slice off single-crystalline AlGaN/GaN layers while preserving their microstructural quality. A double heterostructure design with a symmetric strain profile is employed to ensure minimal residual strain in freestanding NMs after release. The mobility of the two-dimensional electron gas (2DEG), formed by the AlGaN/GaN heterostructure, is noticeably superior to previously reported values of many other NMs. AlGaN/GaN nanomembrane HEMTs are fabricated on SiO 2 and flexible polymeric substrates. Excellent electrical characteristics, including a high ON/OFF ratio and transconductance, suggest that III-Nitrides nanomembranes are capable of supporting high performance applications.

  14. Validated thermodynamic prediction of AlP and eutectic (Si) solidification sequence in Al-Si cast alloys

    International Nuclear Information System (INIS)

    Liang, S M; Schmid-Fetzer, R

    2016-01-01

    The eutectic microstructure in hypoeutectic Al-Si cast alloys is strongly influenced by AlP particles which are potent nuclei for the eutectic (Si) phase. The solidification sequence of AlP and (Si) phases is, thus, crucial for the nucleation of eutectic silicon with marked impact on its morphology. This study presents this interdependence between Si- and P-compositions, relevant for Al-Si cast alloys, on the solidification sequence of AlP and (Si). These data are predicted from a series of thermodynamic calculations. The predictions are based on a self-consistent thermodynamic description of the Al-Si-P ternary alloy system developed recently. They are validated by independent experimental studies on microstructure and undercooling in hypoeutectic Al-Si alloys. A constrained Scheil solidification simulation technique is applied to predict the undercooling under clean heterogeneous nucleation conditions, validated by dedicated experimental observations on entrained droplets. These specific undercooling values may be very large and their quantitative dependence on Si and P content of the Al alloy is presented. (paper)

  15. Phase diagrams of aluminium alloys of Al-Cu-Mg, Al-Mg-Si-Cu, and Al-Mg-Li system

    International Nuclear Information System (INIS)

    Ber, L.B.; Kaputkin, E.Ya.

    2001-01-01

    Isothermal diagrams of phase transformations (DPT) and temperature-time charts (TTC) of variation of electric conductivity and of mechanical features at tension were plotted following thermal treatment according to the pattern of direct hardening and ageing and according to the pattern of normal aging for D16 commercial alloy, Al-Cu-Mg model alloy of the same system, AD37 commercial alloys of Al-Mg-Si-Cu and 1424 one of Al-Li-Mg system. Phase transformations were studied by means of fluorescence electron microscopy, micro-X-ray spectral analysis, X-ray phase analysis of single crystals and polycrystals and differential scanning calorimetry. For every alloy comparison of TTC and DPT enables to clarity the mechanism of phase composition effect on features and to optimize conditions of hardening cooling and ageing [ru

  16. Superhydrophobic ZnAl double hydroxide nanostructures and ZnO films on Al and glass substrates

    Energy Technology Data Exchange (ETDEWEB)

    De, Debasis, E-mail: debasis.de@bcrec.ac.in [Electronics and Instrumentation Engineering Department, Dr. B C Roy Engineering College, Durgapur, West Bengal 713206 (India); Sarkar, D.K. [Centre Universitaire de Recherche sur l' Aluminium (CURAL), L' Université du Québec à Chicoutimi, 555 Blvd. Université, Chicoutimi, Saguenay, Québec G7H 2B1 (Canada)

    2017-01-01

    Superhydrophobic nanostructured ZnAl: layered double hydroxides (LDHs) and ZnO films have been fabricated on Al and glass substrates, respectively, by a simple and cost effective chemical bath deposition technique. Randomly oriented hexagonal patterned of ZnAl: LDHs thin nanoplates are clearly observed on Al-substrate in the scanning electron microscopic images. The average size of these hexagonal plates is ∼4 μm side and ∼30 nm of thickness. While on the glass substrate, a oriented hexagonal patterned ZnO nanorods (height ∼5 μm and 1 μm diameter) are observed and each rod is further decorated throughout the top few nanometers with several nanosteps. At the top of the nanorod, a perfectly hexagonal patterned ZnO surface with ∼250 nm sides is observed. The tendency to form hexagonal morphological features is due to the hexagonal crystal structure of ZnO confirmed from X-ray diffraction patterns and transmission electron microscopy image. The ZnAl: LDHs and/or ZnO coated substrates have been passivated by using stearic acid (SA) molecules. Infrared spectra of passivated ZnAl: LDHs coated substrates confirm the presence of SA. X-ray diffraction pattern also corroborates the results of infrared spectrum. The contact angle of the as prepared samples is zero. The superhydrophobicity is achieved by observing contact angle of ∼161° with a hysteresis of ∼4° for Al-substrate. On the glass substrate, a higher contact angle of ∼168° with a lower hysteresis of ∼3° is observed. A lower surface roughness of ∼4.93 μm is measured on ZnAl: LDHs surface layer on the Al substrate as compare to a higher surface roughness of 6.87 μm measured on ZnO layer on glass substrate. The superhydrophobicity of passivated nanostructured films on two different substrates is observed due to high surface roughness and low surface energy. - Highlights: • ZnAl: layered double hydroxides (LDHs) nanoplates are fabricated on Al substrate. • ZnO nanorods are fabricated on

  17. Formation of Nb3Al in powder processed Nb-Al superconductors

    International Nuclear Information System (INIS)

    Johnson, P.E.

    1987-05-01

    In high magnetic fields, the critical current density is strongly dependent on the upper critical field, which is determined primarily by the stoichiometry of the Nb 3 Al. The critical temperature (T/sub c/), like the upper critical field, is considered to be a measure of the ''intrinsic'' quality of the superconductor, indicating the stoichiometry, order, and strain. If the A15 phase is stoichiometric and well ordered, a high T/sub c/ (and high H/sub C 2 /) is expected, regardless of the volume fraction of superconductor. On the other hand, if sigma phase is present with the A15, the resultant composition gradient across the sigma-A15 interface(s) requires that some of the A15 be off-stoichiometric, and therefore that the T/sub c/ (and H/sub C 2 /) be low. Thus the extent of the A15 (Nb 3 Al) reaction and the quality of the A15 formed are interdependent. This work focuses on the factors that control the extent of Nb 3 Al formation in Nb/Al powder wires. The morphology and content of the reacted and unreacted wires are studied in optical, SEM, and TEM micrographs. Critical current density data and its dependence on processing are explained in terms of the unreacted microstructure and its effect on the extent of Nb 3 Al formation. As a method of improving the critical current density, a new variation of the conventional powder process for wire manufacturing is developed and tested

  18. Displasia ectodérmica: Presentación de un caso ECTODERMAL DYSPLASIA: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Jaime Diez Betancourt

    2005-04-01

    Full Text Available La displasia ectodérmica es una enfermedad genética muy rara, la cual se encuentra caracterizada por manifestaciones odontoestomatológicas imponentes; presenta aspectos interesantes desde el punto de vista del diagnóstico, así como la rehabilitación conjunta ortodóntica, protésica y estética. En el Servicio de Ortodoncia de la Clínica Estomatológica INPE concurrió una paciente de 9 años de edad con manifestaciones clínicas de displasia ectodérmica, principalmente anodoncia, hipoplasia de dientes anteriores y malposición dentaria, con dientes de aspecto de conos y anomalías de las cúspides, y con afectación sicológica de la paciente. Con un tratamiento conjunto de ortodoncia y del estomatólogo general integra,l se logró restituir la maloclusión, y al mismo tiempo, con el tratamiento estético, se devolvió a la paciente a la vida socialmente útil y afectiva en vísperas de cumplir los 15 años.The ectodermic dysplasia is a very rare genetic disease that is characterized by impressive odontostomatological manifestations. It presents interesting aspects regarding the diagnosis and the joined orthodontic, prosthetic and aesthetic rehabilitation. A 9-year-old patient with clinical manifestations of ectodermic dysplasia, mainly anodontia, hypoplasia of the anterior tooth and tooth malposition, with cone-like tooth, abnormalities of the cusps and psychological affectation, presented for care at the Orthodontics Service of the INPE Dental Clinic. By a joint treatment of orthdontics and the general stomatologist, it was possible to restore malocclusion and, at the same time, with the aesthetic treatment the patient was returned to the socially useful and affective life before being 15.

  19. Factores de riesgo asociados a trastornos temporomandibulares

    Directory of Open Access Journals (Sweden)

    Elizabeth de la Torre Rodríguez

    Full Text Available Introducción: los trastornos temporomandibulares conforman un conjunto de condiciones músculo-esqueléticas que afectan la articulación temporomandibular, músculos de la masticación y estructuras anatómicas adyacentes; complejas y moldeadas por diversos factores de riesgo interactuantes. Resulta de gran valor el conocimiento de los mismos para poder actuar sobre ellos e impedir la aparición y/o agravamiento de la enfermedad. Objetivo: caracterizar a la población objeto de estudio según las variables sociodemográficas: edad y sexo, factores precipitantes, hábitos parafuncionales y trastornos oclusales. Métodos: se realizó un estudio observacional, descriptivo, de corte transversal, en el Hospital Clinicoquirúrgico Universitario «Miguel Enríquez», en una población constituida por 181 pacientes que acudieron a la Consulta Multidisciplinaria de Atención Integral de la articulación temporomandibular en el período comprendido de enero del 2010 a enero del 2012. Resultados: del total de pacientes, 133 pertenecían al sexo femenino, para un 73 %. El grupo de edades de 25-35 años estuvo representado por 45 pacientes para un 24 %. En el 79 % se observó bruxismo, en el 24 % interposición lingual en tanto que el 52 % presentó dientes ausentes no restituidos. Conclusiones: el sexo predominante fue el femenino y el grupo de edades más representado es el de 25-35 años. El factor predisponente que más se observó fue los dientes ausentes no restituidos protésicamente. El factor precipitante que predominó fue el bruxismo y no se observaron factores perpetuantes de los trastornos temporomandibulares.

  20. Al-Si/B{sub 4}C composite coatings on Al-Si substrate by plasma spray technique

    Energy Technology Data Exchange (ETDEWEB)

    Sarikaya, Ozkan [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Anik, Selahaddin [Sakarya University, Faculty of Engineering, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Aslanlar, Salim [Sakarya University, Faculty of Technical Education, Department of Mechanical Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Cem Okumus, S. [Sakarya University, Faculty of Engineering, Department of Metallurgical and Materials Engineering, Esentepe Campus, Sakarya 54187 (Turkey); Celik, Erdal [Dokuz Eylul University, Engineering Faculty, Department of Metallurgical and Materials Engineering, Buca, Izmir 35160 (Turkey)]. E-mail: erdal.celik@deu.edu.tr

    2007-07-01

    Plasma-sprayed coatings of Al-Si/B{sub 4}C have been prepared on Al-Si piston alloys for diesel engine motors. The Al-Si/B{sub 4}C composite powders including 5-25 wt% B{sub 4}C were prepared by mixing and ball-milling processes. These powders were deposited on Al-Si substrate using an atmospheric plasma spray technique. The coatings have been characterised with respect to phase composition, microstructure, microhardness, bond strength and thermal expansion. It was found that Al, Si, B{sub 4}C and Al{sub 2}O{sub 3} phases were determined in the coatings with approximately 600 {mu}m thick by using X-ray diffraction analysis. Scanning electron microscope observation revealed that boron carbide particles were uniformly distributed in composite coatings and B{sub 4}C particles were fully wetted by Al-Si alloy. Also, no reaction products were observed in Al-Si/B{sub 4}C composite coatings. It was found that surface roughness, porosity, bond strength and thermal expansion coefficient of composite coatings decreased with increasing fraction of the boron carbide particle. It was demonstrated that the higher the B{sub 4}C content, the higher the hardness of coatings because the hardness of B{sub 4}C is higher than that of Al-Si.